ML13289A094

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Sequoyah Nuclear Plan (Sqn) NPDES Permit No. TN0026450 - Application for Renewal
ML13289A094
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 05/02/2013
From: Anderson C M
Tennessee Valley Authority
To: Janjic V
Office of Nuclear Reactor Regulation, State of TN, Dept of Environment & Conservation
Shared Package
ML13289A109 List: ... further results
References
TAC MF0057, TAC MF0058, TN0026450
Download: ML13289A094 (243)
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Tennessee Valley Authority, 1101 Market Street, BR4A, Chattanooga, Tennessee 37402 May 2, 2013 Mr. Vojin Janjic Manager, Permit Section Division of Water Pollution Control Tennessee Department of Environment and Conservation 6th Floor, L&C Annex 401 Church Street Nashville, Tennessee 37243 Dear Mr, Janjic: TENNESSEE VALLEY AUTHORITY (TVA) -SEOUOYAH NUCLEAR PLANT (SON) -NPDES PERMIT NO. TN0026450 -APPLICATION FOR RENEWAL Enclosed is the NPDES renewal application package for SON consisting of EPA Form 1, site map, Form 2C, flow schematic, and NPDES permit address form. TVA would appreciate consideration of the following in the renewed permit. Outfall 101 1. Enclosed is a summary of the Reasonable Potential evaluation and toxicity test results since 2005. As discussed in the enclosure, TVA requests that the current monitoring limit be replaced with an IC2s = 42.8%, which is based on revised effluent flow and is consistent with the Technical Support Document for effluents demonstrating No Reasonable Potential. Toxicity at the instream wastewater concentration would serve only as a hard trigger for accelerated biomonitoring, as stated in the current permit. 2. TVA requests continuation of the 316(a) variance as incorporated in the current permit. Enclosed is SON's revised Alternate Thermal Limit (ATL) study plan, which proposes to conduct biological monitoring at SON during applicable autumn months and once per permit cycle during the summer months to assess the aquatic community. TVA believes this approach is the most efficient use of resources and will provide TDEC with the data necessary for continued support of SaN's permitted ATL under Section 316(a) of the Clean Water Act. Based on the results summarized in the enclosed Reservoir Fish Assemblage Index Report, TVA believes that thermal discharges from SON have not had a negative effect on the maintenance of a balanced indigenous fish population in Chickamauga Reservoir. Also enclosed are additional reports for studies related to Clean Water Act Section 316 evaluations as required by Part III.F. of the current permit and the study to confirm the calibration of the numerical model as required by Part III.G.

Mr. Vojin Janjic Page 2 May 2,2013 Outfall 103 1. This is an internal monitoring point (IMP) for various flows treated in the low volume waste treatment pond (L VWTP) and ultimately discharges through the Diffuser Pond at Outfall 101. Turbine building sump (TBS) flows are the primary wastewaters treated in the LVWTP. TVA requests when flows are routed through the permitted alternate path of the Yard Drainage Pond that compliance monitoring be required at Outfall 101 for IMP 103 parameters and frequencies. 2. TVA requests the monitoring frequency for Total Suspended Solids and Oil and Grease at IMP 103 be reduced to once per month. SON has consistently demonstrated compliance reliability with established permit limitations for these parameters. 3. TVA requests the monitoring frequency for flow and be reduced to once per week in the renewal permit. TVA requests that flow measurements be recorded based on instantaneous flow meter readings. Historical data demonstrates that SON has consistently maintained compliance with the permit for these parameters. In addition, project planning is underway to upgrade the existing pH control process by using carbon dioxide injection to adjust L VWTP discharge pH. Outfall 107 1. This is an internal monitoring point for discharges of metal cleaning wastewater and storm water from a lined pond and an unlined pond. The existing permit allows that storm water be discharged from these ponds without monitoring since metal cleaning wastes are no longer discharged to these ponds. TVA requests approval through the renewal permit to also discharge stormwater via alternate paths of the Yard Drainage Pond and Condenser Cooling Water Discharge Channel, which both ultimately discharge through the Diffuser Pond at Outfall 101. 2. Since the influent lines from the plant to the Metal Cleaning Waste Treatment Ponds have been disconnected, SON plans to close these ponds in the future. The final closure plan will be submitted to the Division for review and approval prior to the construction phase. To facilitate dewatering for future closure, TVA requests the existing language found in Part 1.A.3. be replaced with the following in the renewal permit. TVA Sequoyah Nuclear Plant is authorized to discharge rain water from the Metal Cleaning Waste *Treatment Ponds to the Low Volume'Waste Treatment Pond, the Yard Drainage Pond, or the Condenser Cooling Water Discharge Channel, which ultimately discharges in the Diffuser Pond (Outfall 101). The permittee is not required to monitor discharge through IMP 107 for routine decanting of accumulated rainwater.

Mr. Vojin Janjic Page 3 May 2,2013 During the process of closing the Metal Cleaning Waste Treatment Ponds, al/ monitoring requirements at IMP 107 shall be waived to facilitate complete dewatering. During the dewatering process, samples shall be collected for TSS, O&G, copper, iron and flow at Outfall 101 to ensure the water quality of the receiving stream is protected. Due to the additional residence time within the Diffuser Pond, these parameters shall be monitored daily at Outfall 101 from the beginning of the dewatering event(s) through three days following termination of the dewatering. All monitoring results shall be reported in the DMR for Outfall 101. Miscellaneous 1. TVA requests that the following language be included in the introduction to Part I.A. We believe this would alleviate the need for preparing a separate water quality certification for the Nuclear Regulatory Commission. This TN-NPDES permit also constitutes the State's certification under Section 401 of the Clean Water Act for the purpose of obtaining any federal license for activities resulting in the discharges covered under the TN-NPDES permit. 2. SON discharges storm water from outfalls covered under the Tennessee MUlti-Sector General Permit, tracking number TNR050015. TVA requests the requirement in Part II.C. of the NPDES permit to maintain signage for storm water runoff be removed in the renewal permit. 3. In January 1990, TVA received a consent order from the Division requiring that SON submit a plan to the Division detailing TVA's systems and procedures to prevent damage to fish and aquatic life from TVA's discharges in response to an alleged fish kill incident. A copy of this Order is enclosed for your convenience. Pursuant to the plan submitted to the Division, SON has maintained an aeration system at the intake forebay for the purpose of compliance with this Order. TVA now requests the following language be incorporated in Part III of the renewal permit to facilitate resolution or termination of the long-standing Order. TVA shal/provide supplemental aeration, as necessary, in Jaw-oxygen zones of the intake forebay area to serve as a fish refuge. Aeration may be temporarily discontinued during periods of maintenance. The permittee may request approval from the Division to permanently discontinue aeration upon demonstration that supplemental aeration is not necessary for fish survival in the intake forebay. 4. TVA requests the existing language found in Part IV.B. for maintaining a Biocide/Corrosion Treatment Plan (B/CTP) be replaced with the following in the renewal permit. This language is consistent with that found in other TN-NPDES permits. The use of toxic chemicals and biocides at the site for process and non-process flows shall be managed under a Biocide/Corrosion Treatment Plan (BlCTP). The BlCTP shall describe chemical applications and macroinvertebrate controls, include all material feed rates, and proposed monitoring schedule(s). The permittee shall conduct treatments of Mr. Vojin Janjic Page 4 May 2,2013 intake or process waters under this permit using biocides, dispersants, surfactants, corrosion inhibiting chemicals, or detoxification chemicals in accordance with conditions approved and specified in the BlCTP. The permittee shall maintain the BlCTP at the facility and make the plan available to the pennit issuing authority upon request. The permittee shall amend the BlCTP whenever there is a change in the application of the chemical additives or change in the operation of the facility that materially increases the potential for these activities to result in a discharge of significant amounts of pollutants. The Division shall also be notified in writing within 30 days of any material changes that will change the active ingredients or quantities used of any such chemical additives. TVA appreciates your consideration of the information provided herein in the development of the reissued permit. If you have any questions regarding this NPDES permit renewal application, please contact Travis Markum at (423) 751-2795 in Chattanooga or by email at trmarkum@tva.gov. Sincerely, M . C hia M. Anderson Senior Manager Water and Waste Compliance Enclosure cc (Enclosure): Dr. Richard Urban Manager, Chattanooga Environmental Field Office Division of Water Pollution Control State Office Building, Suite 550 540 McCallie Avenue Chattanooga, Tennessee 37402-2013 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Please print or type in the unshaded areas only(fill-in areas are spaced for elite type, I.e., 12 characters/inch).Form Approved. OMB No. 2040-0086. Approval expires 5-31-92.FORMU.S. ENVIRONMENTAL PROTECTION AGENCYI. EPA I.D. NUMBER1GENERAL INFORMATIONGENERALConsolidated Permits Program(Read the "General Instructions" before starting.)12131415LABEL ITEMSGENERAL INSTRUCTIONSIf a preprinted label has been provided, affix in the I. EPA I.D. NUMBERdesignated space. Review the information care-fully; if any of it is incorrect, cross through it and enter the correct data in the appropriate fill-in areaIII. FACILITY NAMEbelow. Also, if any of the preprinted data is absent PLEASE PLACE LABEL IN THIS SPACE(the area to the left of the label space lists the information that should appear), please provide it V. FACILITYin the proper fill-in area(s)below. If the label is MAILING ADDRESScomplete and correct, you need not complete Items 1, III, V, and VI (except VI-B which must be completed regardless). Complete all items if no VI. FACILITYlabel has been provided. Refer to the instructions LOCATIONfor detailed item descriptions and for the legal authorizations under which this data is collected.II. POLLUTANT CHARACTERISTICSINSTRUCTIONS: Complete A through J to determine whether you need to submit any permit application forms to the EPA. if you answer "yes" to any questions, youmust submit this form and the supplemental form listed in the parenthesis following the question. Mark "X" in the box in the third column if the supplemental form isattached. If you answer "no" to each question, you need not submit any of these forms. You may answer "no" if your activity is excluded from permit requirements; seeSection C of the instructions. See also, Section D of the instructions for definitions of bold-faced terms.MARK 'X'MARK 'X'SPECIFIC QUESTIONSYESNOFORMSPECIFIC QUESTIONSYESNOFORMATTACHEDATTACHEDA.Is this facility a publicly owned treatment worksB.Does or will this facility (either existing or proposed)which results in a discharge to waters of the U.S.?include a concentrated animal feeding operation or(FORM 2A)aquatic animal production facility which results in 161718a dischargeto waters of the U.S.? (FORM 2B)192021C. Is this a facility which currently results in dischargesD.Is this a proposed facility (other than those describedto waters of the U.S. other than those described inin A or B above)which will result in a discharge toA or B above? (FORM 2C)222324waters of the U.S.? (FORM 2D)252627E.Does or will this facility treat, store, or dispose ofF.Do you or will you inject at this facility industrial orhazardous wastes? (FORM 3)municipal effluent below the lowermost stratum con-taining, within one quarter mile of the well bore, 282930underground sources of drinking water? (FORM 4)313233G.Do you or will you inject at this facility any producedH.Do you or will you inject at this facility fluids for specialwaterorotherfluidswhicharebroughttothesurprocessessuchasminingofsulfurbytheFrasch0400205TN564XXXXXXXFEPAST/ACDwater or other fluids which are brought to the sur-processes such as mining of sulfur by the Fraschface in connection with conventional oil or naturalprocess, solution mining of minerals, in situ combus-gas production, inject fluids used for enhancedtion of fossil fuel, or recovery of geothermal energy?recovery of oil or natural gas, or inject fluids for(FORM 4)storage of liquid hydrocarbons? (FORM 4)343536373839I.Is this facility a proposed stationary sourcewhich isJ.Is this facility a proposed stationary source which isone of the 28 industrial categories listed in the in-NOT one of the 28 industrial categories listed in the structions and which will potentially emit 100 tonsinstructions and which will potentially emit 250 tonsper year of any air pollutant regulated under theper year of any air pollutant regulated under the Clean Clean Air Act and may affect or be located in anAir Act and may affect or be located in an attainmentattainment area? (FORM 5)404142area? (FORM 5)434445III. NAME OF FACILITY1SKIPTVASEQUOYAHNUCLEARPLANT1516-293069IV. FACILITY CONTACTA. NAME & TITLE (last, first, & title)B. PHONE (area code & no.)2JOHN T.CARLIN,VICEPRESIDENT423843700115164546-4849-5152-55V. FACILITY MAILING ADDRESSA. STREET OR P.O. BOX3P.O.BOX2000,OPS4A-SQN151645B. CITY OR TOWNC. STATED. ZIP CODE4SODDYDAISYTN37379151640414247 -51VI. FACILITY LOCATION A. STREET, ROUTE NO. OR OTHER SPECIFIC IDENTIFIER5SEQUOYAHACCESSROAD15545B. COUNTY NAMEHAMILTON 4670C. CITY OR TOWND. STATEE. ZIP CODEF. COUNTY CODE(if known)6SODDYDAISYTN37379151640414247 15152-54EPA Form 3510-1 (8-90)CONTINUE ON PAGE 2XXX XCCCCCC ELECTRIC SERVICES ENNESSEE V ALL e Y AUTHORITY Operafing Permil, Cooling Tower, Unill (see ned page forofhtJr air ptlrmits) SON Inert Landfill Permil MLllfi*Sector General (stonnwater) i , Ii slorage, or disposal Include II oltler SLlrtace water bodies in Itle map area. See instructions Sequoyan NLlclear Plant (SON) prodLlceS electric power by tnermonLlclear li"ion Jonn T. Cartin Site Vice President, SeqLloyan NLlclear Plant , ,

Form 1 - General Section X - Existing Environmental PermitsChattanooga-Hamilton County Air Pollution Control Bureau4150-30600701-03COperating Permit, Cooling Tower, Unit 24150-30700804-06COperating Permit, Insulation Saw A and Saw B 4150-10200501-08COperating Permit, Auxiliary Boilers A and B 4150-30703099-09COperating Permit, Carpenter Shop 4150-30900203-10COperating Permit, Abrasive Blasting Operation 4150-20200102-11COperating Permit, Emergency Generators 1A, 1B, 2A, 2B andBlackout Generators 1 and 2 5°5' 15 W85Intake Outfall 116Outfall 117Outfall 118IMP103IMP 107ForebayOutfall 110Outfall 101E35°12' 30 NOutfall 101IMP 1030.75 mi0TVA Sequoyah Nuclear PlantNPDES Permit No. TN0026450Hamilton CountyApril 2013 Please print or type in the unshaded areas only. EPA I.D. NUMBER (copy from Item 1 of Form 1) TN5640020504 Form Approved. OMB No. 2040-0086. Approval expires 8-31-98. FORM 2C NPDES EPA U.S. ENVIRONMENTAL PROTECTION AGENCY APPLICATION FOR PERMIT TO DISCHARGE WASTEWATER EXISTING MANUFACTURING, COMMERCIAL, MINING AND SILVICULTURAL OPERATIONS Consolidated Permits Program I. OUTFALL LOCATION For each outfall, list the latitude and longitude of its location to the nearest 15 seconds and the name of the receiving water. A. OUTFALL NUMBER (list) B. LATITUDE C. LONGITUDE D. RECEIVING WATER (name) 1. DEG. 2. MIN. 3. SEC. 1. DEG. 2. MIN. 3. SEC. 101 35 12 30 85 5 15 Tennessee River 101E 35 13 15 85 5 45 Tennessee River IMP 103 35 8 15 85 8 0 SQN Diffuser Pond IMP 107 35 8 30 85 8 0 SQN Low Volume Waste Treatment Pond 110 35 13 30 85 5 15 Intake Forebay 116 35 13 30 85 5 15 Tennessee River 117 35 13 30 85 5 0 Tennessee River 118 35 13 30 85 5 15 Intake Forebay II. FLOWS, SOURCES OF POLLUTION, AND TREATMENT TECHNOLOGIES A. Attach a line drawing showing the water flow through the facility. Indicate sources of intake water, operations contributing wastewater to the effluent, and treatment units labeled to correspond to the more detailed descriptions in Item B. Construct a water balance on the line drawing by showing average flows between intakes, operations, treatment units, and outfalls. If a water balance cannot be determined (e.g., for certain mining activities), provide a pictorial description of the nature and amount of any sources of water and any collection or treatment measures. B. For each outfall, provide a description of: (1) All operations contributing wastewater to the effluent, including process wastewater, sanitary wastewater, cooling water, and storm water runoff; (2) The average flow contributed by each operation; and (3) The treatment received by the wastewater. Continue on additional sheets if necessary. 1. OUT- FALL NO (list) 2. OPERATION(S) CONTRIBUTING FLOW 3. TREATMENT a. OPERATION (list) b. AVERAGE FLOW(include units) a. DESCRIPTION b. LIST CODES FROMTABLE 2C-1 101 Discharges from Diffuser Pond include: 1490.854 MGD Discharge to surface water 4 A Sedimentation 1 U (1) Low Volume Waste Treatment Pond (via Internal Monitoring Point 103): (1.230 MGD) pH adjustment / neutralization 2 K (a) Discharge from metal cleaning waste ponds (IMP 107) (b) Turbine building sump (2) CCW Discharge Channel: (1447.014 MGD) (a) Raw cooling water system Disinfection (other) 2 H (b) Diesel fuel recover trench; high pressure fire water, potable water (c) Condenser Circulating system (d) Stormwater Runoff (3) Cooling tower blowdown basin (40.436 MGD) (a) Essential Raw Cooling Water system Disinfection (other) 2 H (b) Cooling towers (closed/helper mode) stormwater runoff (c) Liquid rad waste treatment system Ion exchange 2 J (d) Steam Generator Blowdown Multi-media filtration 1 Q (4) Yard drainage pond: (2.125 MGD) Sedimentation (settling) 1 U (a) Construction/Demo landfill stormwater (b) Switchyard runoff (c) Various building heat loads (d) Yard drainage system (5) Net Storm Water (Runoff, precipitation, less evaporation) (0.049 MGD) 101E Discharges from Diffuser Pond during emergency conditions only. 0 MGD Discharge to surface water 4 A OFFICIAL USE ONLY (effluent guidelines sub-categories) EPA Form 3510-2C (8-90) PAGE 1a OF 4 CONTINUE ON PAGE 1b Please print or type in the unshaded areas only. EPA I.D. NUMBER (copy from Item 1 of Form 1) TN5640020504 Form Approved. OMB No. 2040-0086. Approval expires 8-31-98. FORM 2C NPDES EPA U.S. ENVIRONMENTAL PROTECTION AGENCY APPLICATION FOR PERMIT TO DISCHARGE WASTEWATER EXISTING MANUFACTURING, COMMERCIAL, MINING AND SILVICULTURAL OPERATIONS Consolidated Permits Program I. OUTFALL LOCATION For each outfall, list the latitude and longitude of its location to the nearest 15 seconds and the name of the receiving water. A. OUTFALL NUMBER (list) B. LATITUDE C. LONGITUDE D. RECEIVING WATER (name) 1. DEG. 2. MIN. 3. SEC. 1. DEG. 2. MIN. 3. SEC. See Page 1a II. FLOWS, SOURCES OF POLLUTION, AND TREATMENT TECHNOLOGIES C. Attach a line drawing showing the water flow through the facility. Indicate sources of intake water, operations contributing wastewater to the effluent, and treatment units labeled to correspond to the more detailed descriptions in Item B. Construct a water balance on the line drawing by showing average flows between intakes, operations, treatment units, and outfalls. If a water balance cannot be determined (e.g., for certain mining activities), provide a pictorial description of the nature and amount of any sources of water and any collection or treatment measures. D. For each outfall, provide a description of: (1) All operations contributing wastewater to the effluent, including process wastewater, sanitary wastewater, cooling water, and storm water runoff; (2) The average flow contributed by each operation; and (3) The treatment received by the wastewater. Continue on additional sheets if necessary. 1. OUT- FALL NO (list) 2. OPERATION(S) CONTRIBUTING FLOW 3. TREATMENT a. OPERATION (list) b. AVERAGE FLOW(include units) a. DESCRIPTION b. LIST CODES FROMTABLE 2C-1 IMP 103 Discharges from Low Volume Waste Treatment Pond (LVWTP): 1.230 MGD Sedimentation (Settling) 1 U pH adjustment / neutralization 2 K (1) Discharges from metal cleaning waste (0.0022 MGD) ponds (IMP 107) (2) Turbine Building Sump: (1.047 MGD) (a) Miscellaneous Low Volume Wastewaters (b) Turbine building floor and equipment drains pH adjustment / neutralization 2 K (c) Condensate demin. regeneration waste (d) Secondary system leaks and draindown (e) Steam Generator blowdown (f) Component Cooling System wastewater (g) Miscellaneous equipment cooling (h) Ice condenser waste Sedimentation (settling) 1 U (i) Alum sludge ponds (WTP) Landfill 5 Q (3) Neutral waste sump (WTP) (0.177 MGD) (4) Net Storm Water (Runoff, precipitation, less evaporation) (0.004 MGD) IMP 107 Discharges from Metal Cleaning Waste Ponds: 0.0022 MGD Sedimentation (Settling) 1 U pH adjustment / neutralization 2 K (1) Metal cleaning waste (0.000 MGD)** Chemical precipitation 2 C (2) Net Storm Water (Runoff, precipitation, less evaporation) (0.0022 MGD) Chemical oxidation 2 B Flocculation 1 G ** Influent lines to MCWP are disconnected Last MCWP discharge occurred on 5/31/2006 OFFICIAL USE ONLY (effluent guidelines sub-categories) EPA Form 3510-2C (8-90) PAGE 1b OF 4 CONTINUE ON PAGE 1c Please print or type in the unshaded areas only. EPA I.D. NUMBER (copy from Item 1 of Form 1) TN5640020504 Form Approved. OMB No. 2040-0086. Approval expires 8-31-98. FORM 2C NPDES EPA U.S. ENVIRONMENTAL PROTECTION AGENCY APPLICATION FOR PERMIT TO DISCHARGE WASTEWATER EXISTING MANUFACTURING, COMMERCIAL, MINING AND SILVICULTURAL OPERATIONS Consolidated Permits Program I. OUTFALL LOCATION For each outfall, list the latitude and longitude of its location to the nearest 15 seconds and the name of the receiving water. A. OUTFALL NUMBER (list) B. LATITUDE C. LONGITUDE D. RECEIVING WATER (name) 1. DEG. 2. MIN. 3. SEC. 1. DEG. 2. MIN. 3. SEC. See Page 1a II. FLOWS, SOURCES OF POLLUTION, AND TREATMENT TECHNOLOGIES E. Attach a line drawing showing the water flow through the facility. Indicate sources of intake water, operations contributing wastewater to the effluent, and treatment units labeled to correspond to the more detailed descriptions in Item B. Construct a water balance on the line drawing by showing average flows between intakes, operations, treatment units, and outfalls. If a water balance cannot be determined (e.g., for certain mining activities), provide a pictorial description of the nature and amount of any sources of water and any collection or treatment measures. F. For each outfall, provide a description of: (1) All operations contributing wastewater to the effluent, including process wastewater, sanitary wastewater, cooling water, and storm water runoff; (2) The average flow contributed by each operation; and (3) The treatment received by the wastewater. Continue on additional sheets if necessary. 1. OUT- FALL NO (list) 2. OPERATION(S) CONTRIBUTING FLOW 3. TREATMENT a. OPERATION (list) b. AVERAGE FLOW(include units) a. DESCRIPTION b. LIST CODES FROMTABLE 2C-1 110 Discharges include wastewater from: 0.058 MGD Discharge to surface waters 4 A (1) ERCW system ** 0 MGD (2) Cooling towers (closed cycle) ** 0 MGD (3) Liquid rad waste treatment system ** 0 MGD (4) Net Storm Water (Runoff, precipitation, less evaporation) (0.058 MGD) ** Recycle cooling water during closed mode operation is discharged through Outfall 110. Outfall 110 has been inactive for approximately 18 years, but remains in the event the plant goes into closed mode. 116 CCW Intake Trash sluice 0.006 MGD Discharge to surface waters 4 A 117 Essential Raw Cooling Water screen and strainer backwash 0.014 MGD Discharge to surface waters 4 A 118 Dredge Pond 0 MGD Discharge to surface waters 4 A Sedimentation (settling) 1 U Filtration 1 Q Pond is not in service at this time. Therefore outfall 118 is inactive. Only stormwater from surrounding vegetated area discharges. No industrial activity in area. If in service, the pond would provide sedimentation during dredge activities and filtration for lower depth waste waters. OFFICIAL USE ONLY (effluent guidelines sub-categories) EPA Form 3510-2C (8-90) PAGE 1c OF 4 CONTINUE ON PAGE 2

CONTINUED FROM PAGE 1c C. Except for storm runoff, leaks, or spills, are any of the discharges described in Items II-A or B intermittent or seasonal? YES (complete the following table) NO (go to Section III) 1. OUTFALL NUMBER (list) 2. OPERATION(s) CONTRIBUTING FLOW (list) 3. FREQUENCY 4. FLOW a. DAYS PER WEEK (specify average) b. MONTHS PER YEAR (specify average) a. FLOW RATE (in mgd) b. TOTAL VOLUME (specify with units) c. DURATION (in days) 1. LONG TERM AVERAGE 2. MAXIMUM DAILY 1. LONG TERM AVERAGE 2. MAXIMUM DAILY IMP 107 110 116 117 118 Metal cleaning waste waters Cooling Tower blowdown basin CCW Intake Trash Sluice ERCW Traveling Screen and ERCW Strainer Backwash ERCW Dredge Pond (a)

(b) 1 4 3 (c) (a)

(b) 12 12 12 (c) (a)

(b) 0.0060 0.0100 0.0040 (c) (a)

(b) 0.0450 0.0216 0.0096 (c) (a)

(b) 0.0060 MG 0.0100 MG 0.0040 MG (c) (a)

(b) 0.0450 MG 0.0216 MG 0.0096 MG (c) (a)

(b) < 1 < 1 < 1 (c) (a) Last MCWP discharge occurred on 5/31/2006. Influent lines are cut and capped. Stormwater flows only are discharged from pond. (b) Cooling Tower blowdown basin discharges recycled cooling water through outfall 110 while the plant is in closed mode. The plant has not entered closed mode for approximately 18 years. Outfall 110 remains inactive until closed mode operation is necessary, which will result in a discharge flow of approximately 1487.4276 MGD. (c) No dredging operations conducted during current permit cycle. Pond is vegetated and no industrial activity in the area. III. PRODUCTION A. Does an effluent guideline limitation promulgated by EPA under Section 304 of the Clean Water Act apply to your facility? YES (complete Item III-B) NO (go to Section IV) B. Are the limitations in the applicable effluent guideline expressed in terms of production (or other measure of operation)? YES (complete Item III-C) NO (go to Section IV) C. If you answered "yes" to Item III-B, list the quantity which represents an actual measurement of your level of production, expressed in the terms and units used in the applicable effluent guideline, and indicate the affected outfalls. 1. AVERAGE DAILY PRODUCTION 2. AFFECTED OUTFALLS (list outfall numbers) a. QUANTITY PER DAY b. UNITS OF MEASURE c. OPERATION, PRODUCT, MATERIAL, ETC. (specify) IV. IMPROVEMENTS A. Are you now required by any Federal, State or local authority to meet any implementation schedule for the construction, upgrading or operation of wastewater treatment equipment or practices or any other environmental programs which may affect the discharges described in this application? This includes, but is not limited to, permit conditions, administrative or enforcement orders, enforcement compliance schedule letters, stipulations, court orders, and grant or loan conditions. YES (complete the following table) NO (go to Item IV-B) 1. IDENTIFICATION OF CONDITION, AGREEMENT, ETC. 2. AFFECTED OUTFALLS 3. BRIEF DESCRIPTION OF PROJECT 4. FINAL COM- PLIANCE DATE a. NO. b. SOURCE OF DISCHARGE a. RE- QUIRED b. PRO- JECTED B. OPTIONAL: You may attach additional sheets describing any additional water pollution control programs (or other environmental projects which may affect your discharges) you now have underway or which you plan. Indicate whether each program is now underway or planned, and indicate your actual or planned schedules for construction. MARK "X" IF DESCRIPTION OF ADDITIONAL CONTROL PROGRAMS IS ATTACHED EPA Form 3510-2C (Rev. 2-85) PAGE 2 OF 4 CONTINUE ON PAGE 3 CONTINUED FROM PAGE 2 V. INTAKE AND EFFLUENT CHARACTERISTICS A, B, & C: See instructions before proceeding - Complete one set of tables for each outfall - Annotate the outfall number in the space provided. NOTE: Tables V-A, V-B, and V-C are included on separate sheets numbered V-1 through V-9. D. Use the space below to list any of the pollutants listed in Table 2c-3 of the instructions, which you know or have reason to believe is discharged or may be discharged from any outfall. For every pollutant you list, briefly describe the reasons you believe it to be present and report any analytical data in your possession. 1. POLLUTANT 2. SOURCE 1. POLLUTANT 2. SOURCE See site Biocide Corrosion Treatment Plan (B/CTP).

Dimethylamine (The use of dimethylamine will not result in detectible quantities at Outfall 101)

Steam Generator Layup VI. POTENTIAL DISCHARGES NOT COVERED BY ANALYSIS Is any pollutant listed in Item V-C a substance or a component of a substance which you currently use or manufacture as an intermediate or final product or byproduct? YES (list all such pollutants below) NO (go to Item VI-B)

EPA FORM 3510-2C (8-90) PAGE 3 OF 4 CONTINUE ON PAGE 4 EPA I.D. NUMBER (copy from Item 1 of Form 1) TN5640020504 reason any biological test for 8ClJle or chronic toxicity has been made on sny of your discharges or on your discharge within the last 3 years? 181 YES (identify the tes/(s) and describe their purposes below) o NO (go to Section VIII) Per the requirements of the SON NPOES Permit No. TN0026450, IC2510xicity testing has been conducted on discharges from Outfall 101 once per year when oxidizing biocides are being used and once per year when non-oxidizing biocides are being used. Results are routinely submitted with the appropriate Discharge Monitoring Reports. it.;;;\,.",,;;;;; .. by a contract laboratory or consulting firm? 181 YES (Iisl the n8f11fJ, address, and telephone number of, and pollutants analyzed by, each such laboniloly or flfm below) A. NAME B. ADDRESS GEL Laboratories LLC PO Box 30712 (843) 556-8171 I . 2040 Savage Road Charleston. SC 29407 o NO (go to Section IX) All pollutants except for field parameterii (temperature, flow, pH, sulfite, and tola! residua! chlorine) I certify under penalty of law Ihal this documenl and al/ attachmenls WBf8 prepared under my direclion or supetvision in accordance with a system designed to aSSUf8 that qualified personnel properly gather and eva/uale the Information submitted. Based on my Inquiry of the person or persons who the system or those persons dif8ctly f8sponsitJ/e forgathering the Informetion, the Information submitted Is, 10 the best of my knowledge and ""., ....... accurate, lam* aware that there are signific8nt penalties for submitting false infOlmation, including tha possibility of fine and PAGE. OF.

PLEASE PRINT OR TYPE IN THE UNSHADED AREAS ONLY. You may report some or all ofEPA I.D. NUMBER (copy from Item 1 of Form 1)this information on separate sheets (use the same format) instead of completing these pages.SEE INSTRUCTIONS.OUTFALL NO.V. INTAKE AND EFFLUENT CHARACTERISTICS (continued from page 3 of Form 2-C)PART A - You must provide the results of at least one analysis for every pollutant in this table. Complete one table for each outfall. See instructions for additional details.2. EFFLUENT3. UNITS4. INTAKE (optional)1. POLLUTANTa. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUE(specify if blank)a. LONG TERM(if available)(if available)d. NO. OFAVERAGE VALUEb. NO. OF(1)(2) MASS(1)(2) MASS(1)(2) MASSANALYSESa. CONCEN-b. MASS(1)(2) MASSANALYSESCONCENTRATIONCONCENTRATIONCONCENTRATIONTRATIONCONCENTRATIONa. BiochemicalOxygen Demand(BOD)b. Chemical Oxygen Demand(COD)c. Total OrganicCarbon (TOC)d. Total SuspendedSolids (TSS)e. Ammonia (as N)VALUEVALUEVALUEVALUEf. Flowg. TemperatureVALUEVALUEVALUEVALUE(winter)°C1017623940.1441mg/Lmg/L mg/L mg/L mg/L<2.001<2.0025.82.87 4.670.129152726.5177034.41 1

123.4 2.84 2.641MGD16161TN56400205041 1

1 1h. TemperatureVALUEVALUEVALUEVALUE(summer)°CMINIMUMMAXIMUMMINIMUMMAXIMUMI. pHSTANDARD UNITSPART B - Mark "X" in column 2-a for each pollutant you know or have reason to believe is present. Mark "X" in column 2-b for each pollutant you believe to be absent. If you mark column 2a for any pollutant which is limitedeither directly, or indirectly but expressly, in an effluent limitations guideline, you must provide the results of at least one analysis for that pollutant. For other pollutants for which you mark column 2a, you mustprovide quantitative data or an explanation of their presence in your discharge. Complete one table for each outfall. See the instructions for additional details and requirements.2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)1. POLLUT-a. BE-b. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMANT ANDLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEb. NO. OFCAS NO.PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1)(2) MASSANAL-(if available)SENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESCONCENTRATIONYSESa. Bromide(24959-67-9)b. Chlorine,Total Residualc. Colord. FecalColiformXe. Fluoride (16984-48-8)f. Nitrate-Nitrite (as N)<0.0720.0<0.10043.27.527.68XX36.7X<0.200X1mg/LX1mg/L0.1671PCU25.81mg/L11mg/L43541 1<0.200<0.0515.0<0.1000.1271 1

1EPA Form 3510-2C (8-90)Page V-1CONTINUE ON PAGE V-2 ITEM V-B CONTINUED FROM PAGE V-12. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)1. POLLUT-a. BE-b. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFANT ANDLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-CAS NO.PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1)(2) MASSYSES(if available)SENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESCONCENTRATIONg. Nitrogen,Total OrganicX1mg/L1(as N)h. Oil andGreaseX1mg/L1I. Phosphorus(as P), TotalX1mg/L1(7723-14-0)j. Radioactivity(1) Alpha, TotalX*(2) Beta,TotalX*(3) Radium,TotalX*(4) Radium226, TotalX*k. Sulfate(as SO4)X1mg/L1(14808-79-8)l. Sulfide(as S)X1mg/L1m Sulfite(as SO4)X1mg/L1(14265-45-3)n. SurfactantsX1mg/L1o. Aluminum,TotalX1mg/L1(7429-90-5)p. Barium,TotalX1mg/L1(7440-39-3)q. Boron,TotalX1mg/L1(7440-42-8)r. Cobalt,TotalX1mg/L1(7440-48-4)s. Iron,Total(7439-89-6)X1mg/L1t. Magnesium,TotalX1mg/L1(7439-95-4)u. Molybdenum,TotalX1mg/L1(7439-98-7)v. Manganese,TotalX1mg/L1(7439-96-5)w. Tin, Total(7440-31-5)X1mg/L1x. Titanium,TotalX1mg/L1(7440-32-6)*Believed absent other than naturally occurring radioactive materials.0.314<3.95<0.050<4.000.0005640.2470.0630<0.005<0.0050.0279 0.0281<0.0010.1316.3612.9<0.100<2.0<0.0500.050<0.05012.9<0.100<2.0<0.050<0.0500.0005840.0395<0.005

<0.0050.0280 0.0178<0.0010.09196.18EPA Form 3510-2CPage V-2CONTINUE ON PAGE V-3 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE 3 OF FORM 2-CPART C - If you are a primary industry and this outfall contains process wastewater, refer to Table 2c-2 in the instructions to determine which of the GC/MS fractions you must test for. Mark "X" in column 2-a for all such GC/MS fractions that apply to your industry and for ALL toxic metals, cyanides, and total phenols. If you are not required to mark column 2-a (secondary industries, nonprocess wastewater outfalls, andnonrequired GC/MS fractions), mark "X" in column 2-b for each pollutant you know or have reason to believe is present. Mark "X" in column 2-c for each pollutant you believe is absent. If you mark column 2a for any pollutant, you must provide the results of at least one analysis for that pollutant. If you mark column 2b for any pollutant, you must provide the results of at least one analysis for that pollutant if youknow or have reason to believe it will be discharged in concentrations of 10 ppb or greater. If you mark column 2b for acrolein, acrylonitrile, 2,4 dinitrophenol, or 2-methyl-4, 6 dinitrophenol, you must provide the results of at least one analysis for each of these pollutants which you know or have reason to believe that you discharge in concentrations of 100 ppb or greater. Otherwise for pollutants for which you mark column 2b, you must either submit at least one analysis or briefly describe the reasons the pollutant is expected to be discharged. Note that there are 7 pages to this part; please review each carefully.

Complete one table (all 7 pages) for each outfall. See instructions for additional details and requirements.1. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONMETALS, CYANIDE, AND TOTAL PHENOLS1M. Antimony,Total (7440-36-0)X<0.0021mg/L<0.00212M. Arsenic, Total(7440-38-2)X<0.0051mg/L<0.00513M. Beryllium,Total, (7440-41-7)X<0.00051mg/L<0.000514M. Cadmium, Total (7440-43-9)X<0.00011mg/L<0.000115M. Chromium, Total (7440-47-3)X<0.0031mg/L<0.00316M. Copper, Total(7440-50-8)X0.001091mg/L<0.00117M. Lead, Total (7439-92-1)X<0.0021mg/L<0.00218M. Mercury, Total(7439-97-6)X0.000002781mg/L19M. Nickel, Total (7440-02-0)X<0.0021mg/L<0.002110M. Selenium, Total (7782-49-2)X<0.0051mg/L<0.005111M. Silver, Total (7440-22-4)X<0.0011mg/L<0.001112M. Thallium, Total (7440-28-0)X<0.00051mg/L<0.0005113M. Zinc, Total (7440-66-6)X<0.0101mg/L<0.010114M. Cyanide,Total (57-12-5)X<0.0051mg/L<0.005115M. Phenols, TotalX<0.0071mg/L<0.0051DIOXIN2,3,7,8-Tetra-DESCRIBE RESULTSchlorodibenzo-PXDioxin (1764-01-6)0.00000169TN5640020504101EPA Form 3510-2C (8-90)Page V-3CONTINUE ON PAGE V-4 CONTINUED FROM PAGE V-31. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - VOLATILE COMPOUNDS1V. Acrolein(107-02-8)X<0.0051mg/L<0.00512V. Acrylonitrile(107-13-1)X<0.0051mg/L<0.00513V. Benzene (71-43-2)X<0.0011mg/L<0.00114V.Bis(Chloro-methyl) EtherX**(542-88-1)5V. Bromoform (75-25-2)X<0.0011mg/L<0.00116V. Carbon TetrachlorideX<0.0011mg/L<0.0011(56-23-5)7V. Chlorobenzene(108-90-7)X<0.0011mg/L<0.00118V. Chlorodi-bromomethaneX<0.0011mg/L<0.0011(124-48-1)9V. Chloroethane (75-00-3)X<0.0011mg/L<0.001110V. 2-Chloro-ethylvinyl EtherX<0.0051mg/L<0.0051(110-75-8)11V. Chloroform (67-66-3)X<0.0011mg/L<0.001112V. Dichloro-bromomethaneX<0.0011mg/L<0.0011(75-27-4)13V. Dichloro-difluoromethaneX*<0.0011mg/L<0.0011(75-71-8)14V. 1,1-Dichloro-ethane (75-34-3)X<0.0011mg/L<0.001115V. 1,2-Dichloro-ethane (107-06-2)X<0.0011mg/L<0.001116V. 1,1-Dichloro-ethylene (75-35-4)X<0.0011mg/L<0.001117V. 1,2-Dichloro-propane (78-87-5)X<0.0011mg/L<0.001118V. 1,3-Dichloro-propylene (542-75-6)X<0.0021mg/L<0.002119V. Ethylbenzene(100-41-4)X<0.0011mg/L<0.001120V. MethylBromide (74-83-9)X<0.0011mg/L<0.001121V. MethylChloride (74-87-3)X<0.0011mg/L<0.0011* NOTE: Bis (Chloro-methyl) Ether and Dichloro-difluoromethane were removed as requirements from 40 CFR Part 123 by US EPA in 1995.EPA Form 3510-2C (8-90)Page V-4CONTINUE ON PAGE V-5 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE V-41. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - VOLATILE COMPOUNDS (continued)22V. MethyleneChloride (75-09-2)X<0.0021mg/L<0.002123V. 1,1,2,2-Tetra-chloroethaneX<0.0011mg/L<0.0011(79-34-5)24V. Tetrachloro-ethylene (127-18-4)X<0.0011mg/L<0.001125V. Toluene(108-88-3)X<0.0011mg/L<0.001126V. 1,2-Trans-Dichloroethylene X<0.0011mg/L<0.0011(156-60-5)27V. 1,1,1-Tri-chloroethaneX<0.0011mg/L<0.0011(71-55-6)28V. 1,1,2-Tri-chloroethaneX<0.0011mg/L<0.0011(79-00-5)29V. Trichloro-ethylene (79-01-6)X<0.0011mg/L<0.001130V. Trichloro-fluoromethane X*<0.0011mg/L<0.0011(75-69-4)31V. VinylChloride (75-01-4)X<0.0011mg/L<0.0011GC/MS FRACTION - ACID COMPOUNDS1A. 2-Chloropheno(95-57-8)X<0.0101mg/L<0.01012A. 2,4-Dichloro-phenol (120-83-2)X<0.0101mg/L<0.01013A. 2,4-Dimethyl-phenol (105-67-9)X<0.0101mg/L<0.01014A. 4,6-Dinitro-O-Cresol (534-52-1)X<0.0101mg/L<0.01015A. 2,4-Dinitro-phenol (51-28-5)X<0.0201mg/L<0.02016A. 2-Nitrophenol(88-75-5)X<0.0101mg/L<0.01017A. 4-Nitrophenol(100-02-7)X<0.0101mg/L<0.01018A. P-Chloro-MCresol (59-50-7)X<0.0101mg/L<0.01019A. Pentachloro-phenol (87-86-5)X<0.0101mg/L<0.010110A. Phenol(108-95-2)X<0.0101mg/L<0.010111A. 2,4,6-Trichloro-phenol (88-06-2)X<0.0101mg/L<0.0101* NOTE: Trichlorofluoromethane was removed as a requirement from 40 CFR Part 123 by US EPA in 1995.TN5640020504101EPA Form 3510-2C (8-90)Page V-5CONTINUE ON PAGE V-6 CONTINUED FROM PAGE V-51. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS1B. Acenaphthene(83-32-9)X2B. Acenaphtylene(208-96-8)X3B. Anthracene(120-12-7)X4B. Benzidine (92-87-5)X 5B.Benzo(a)AnthraceneX(56-55-3)6B.Benzo(a)Pyrene (50-32-8)X 7B. 3,4-Benzo-fluorantheneX(205-99-2)8B. Benzo (ghi)PeryleneX(191-24-2)9B.Benzo(k)FluorantheneX(207-08-9)10B.Bis(2-Chloro-ethoxy) MethaneX(111-91-1)11B.Bis(2-Chloro-ethyl) EtherX(111-44-4)12B.Bis(2-Chloro-isopropyl) Ether X(102-60-1)13B. Bis (2-Ethyl-hexyl) PhthalateX(117-81-7)14B. 4-Bromo-phenyl PhenylXEther (101-55-3)15B. Butyl BenzylPhthalate (85-68-7)X16B. 2-Chloro-naphthaleneX(91-58-7)17B. 4-Chloro-phenyl PhenylXEther (7005-72-3)18B. Chrysene(218-01-9)X19B.Dibenzo(a,h)AnthraceneX(53-70-3)20B. 1,2-Dichloro-benzene (95-50-1)X<0.0011mg/L<0.001121B. 1,3-Dichloro-benzene (541-73-1)X<0.0011mg/L<0.0011EPA Form 3510-2C (8-90)Page V-6CONTINUE ON PAGE V-7 EPAI.D.NUMBER(copyfromItem1ofForm1)OUTFALL NUMBERCONTINUED FROM PAGE V-61. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS (continued)22B. 1,4-Dichloro-benzene (106-46-7)X<0.0011mg/L<0.001123B. 3,3'-Dichloro-benzidineX(91-94-1)24B. DiethylPhthalateX(84-66-2)25B. DimethylPhthalateX(131-11-3)26B. Di-N-ButylPhthalateX(84-74-2)27B. 2,4-Dinitro-toluene (121-14-2)X 28B. 2,6-Dinitro-toluene (606-20-2)X 29B. Di-N-OctylPhthalateX(117-84-0)30B. 1,2-Diphenyl-hydrazine (as Azo-Xbenzene)(122-66-7)31B. Fluoranthene(206-44-0)X 32B. Fluorene(86-73-7)X 33B. Hexachlorobenzene(118-74-1)X 34B. Hexa-chlorobutadieneX(87-68-3)35B. Hexachloro-cyclopentadieneX(77-47-4)36B. Hexachloro-ethane (67-72-1)X37B. Indeno(1,2,3-cd) PyreneX(193-39-5)38B. Isophorone(78-59-1)X 39B. Naphthalene(91-20-3)X40B. Nitrobenzene(98-95-3)X41B. N-Nitro-sodimethylamineX(62-75-9)42B. N-Nitrosodi-PropylamineX(621-64-7)TN5640020504101EPA Form 3510-2C (8-90)Page V-7CONTINUE ON PAGE V-8 CONTINUED FROM PAGE V-71. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS (continued)43B. N-Nitro-sodiphenylamineX(86-30-6)44B. Phenanthrene (85-01-8)X 45B. Pyrene(129-00-0)X 46B. 1,2,4 - Tri-chlorobenzeneX<0.0011mg/L<0.0011(120-82-1)GC/MS FRACTION - PESTICIDES1P. Aldrin(309-00-2)X2P.BHC(319-84-6)X 3P.-BHC(319-85-7)X 4P.-BHC(58-89-9)X 5P.-BHC(319-86-8)X 6P. Chlordane(57-74-9)X 7P. 4,4'-DDT(50-29-3)X 8P. 4,4'-DDE(72-55-9)X 9P. 4,4'-DDD(72-54-8)X 10P. Dieldrin(60-57-1)X 11P.-Endosulfan(115-29-7)X12P.-Endosulfan(115-29-7)X 13P. EndosulfanSulfateX(1031-07-8)14P. Endrin (72-20-8)X15P. Endrin AldehydeX(7421-93-4)16P. Heptachlor(76-44-8)X EPA Form 3510-2C (8-90)Page V-8CONTINUE ON PAGE V-9 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE V-81. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFAVERAGE VALUEAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-a. CONCEN-b. MASS(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONTRATIONGC/MS FRACTION - PESTICIDES (continued)17B. HeptachlorEpoxideX(1024-57-3)18P. PCB-1242(53469-21-9)X19P. PCB-1254 (11097-69-1)X20P. PCB-1221 (11104-28-2)X21P. PCB-1232 (11141-16-5)X22P. PCB-1248 (12672-29-6)X23P. PCB-1260 (11096-82-5)X24P. PCB-1016 (12674-11-2)X25P. Toxaphene(8001-35-2)XTN5640020504101EPA Form 3510-2C (8-90)Page V-9 PLEASE PRINT OR TYPE IN THE UNSHADED AREAS ONLY. You may report some or all ofEPA I.D. NUMBER (copy from Item 1 of Form 1)this information on separate sheets (use the same format) instead of completing these pages.SEE INSTRUCTIONS.OUTFALL NO.V. INTAKE AND EFFLUENT CHARACTERISTICS (continued from page 3 of Form 2-C)PART A - You must provide the results of at least one analysis for every pollutant in this table. Complete one table for each outfall. See instructions for additional details.2. EFFLUENT3. UNITS4. INTAKE (optional)1. POLLUTANTa. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUE(specify if blank)a. LONG TERM(if available)(if available)d. NO. OFAVERAGE VALUEb. NO. OF(1)(2) MASS(1)(2) MASS(1)(2) MASSANALYSESa. CONCEN-b. MASS(1)(2) MASSANALYSESCONCENTRATIONCONCENTRATIONCONCENTRATIONTRATIONCONCENTRATIONa. BiochemicalOxygen Demand(BOD)b. Chemical Oxygen Demand(COD)c. Total OrganicCarbon (TOC)d. Total SuspendedSolids (TSS)e. Ammonia (as N)VALUEVALUEVALUEVALUEf. Flowg. TemperatureVALUEVALUEVALUEVALUE(winter)hTemperatureVALUEVALUEVALUEVALUE<9.11037620.1441mg/Lmg/L mg/L mg/L mg/L<2.0012.9128.3 4.7316.0*0.1701.062.061 1

123.4 2.84 2.64MGD16161TN56400205041 1

1541h. TemperatureVALUEVALUEVALUEVALUE(summer)°CMINIMUMMAXIMUMMINIMUMMAXIMUMI. pHSTANDARD UNITSPART B - Mark "X" in column 2-a for each pollutant you know or have reason to believe is present. Mark "X" in column 2-b for each pollutant you believe to be absent. If you mark column 2a for any pollutant which is limitedeither directly, or indirectly but expressly, in an effluent limitations guideline, you must provide the results of at least one analysis for that pollutant. For other pollutants for which you mark column 2a, you mustprovide quantitative data or an explanation of their presence in your discharge. Complete one table for each outfall. See the instructions for additional details and requirements.2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)1. POLLUT-a. BE-b. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMANT ANDLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEb. NO. OFCAS NO.PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1)(2) MASSANAL-(if available)SENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESCONCENTRATIONYSESa. Bromide(24959-67-9)b. Chlorine,Total Residualc. Colord. FecalColiformXe. Fluoride (16984-48-8)f. Nitrate-Nitrite (as N)72<0.0640.00.10434.86.738.35XXX<0.20X1mg/LX1mg/L0.30125.81411mg/L1 1mg/L1PCU* Value based on historical TSS data from routine grab samples collected as required by the permit and does not include the composite sample result of 7.20 mg/L TSS.1 1<0.200<0.0515.0<0.1000.1271EPA Form 3510-2C (8-90)Page V-1CONTINUE ON PAGE V-2 ITEM V-B CONTINUED FROM PAGE V-12. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)1. POLLUT-a. BE-b. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFANT ANDLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-CAS NO.PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1)(2) MASSYSES(if available)SENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESCONCENTRATIONg. Nitrogen,Total OrganicX1mg/L1(as N)h. Oil andGreaseX55mg/L1I. Phosphorus(as P), TotalX1mg/L1(7723-14-0)j. Radioactivity(1) Alpha, TotalX*(2) Beta,TotalX*(3) Radium,TotalX*(4) Radium226, TotalX*k. Sulfate(as SO4)X1mg/L1(14808-79-8)l. Sulfide(as S)X1mg/L1m Sulfite (as SO4)X1mg/L1(14265-45-3)n. SurfactantsX1mg/L1o. Aluminum,TotalX1mg/L1(7429-90-5)p. Barium,TotalX1mg/L1(7440-39-3)q. Boron,TotalX1mg/L1(7440-42-8)r. Cobalt,TotalX1mg/L1(7440-48-4)s. Iron,Total(7439-89-6)X1mg/L1t. Magnesium,TotalX1mg/L1(7439-95-4)u. Molybdenum,TotalX1mg/L1(7439-98-7)v. Manganese,TotalX1mg/L1(7439-96-5)w. Tin, Total(7440-31-5)X1mg/L1x. Titanium,TotalX1mg/L1(7440-32-6)* Believed absent other than naturally occurring radioactive materials.<5.70.314<3.95<0.05017.00.000920.7400.0966<0.005<0.0050.0312 0.0287<0.0010.2216.3323.7<0.1002.0<0.0500.09680.069612.9<0.100<2.0<0.050<0.0500.0005840.0395<0.005

<0.0050.0280 0.0178<0.0010.09196.18EPA Form 3510-2CPage V-2CONTINUE ON PAGE V-3 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE 3 OF FORM 2-CPART C - If you are a primary industry and this outfall contains process wastewater, refer to Table 2c-2 in the instructions to determine which of the GC/MS fractions you must test for. Mark "X" in column 2-a for all such GC/MS fractions that apply to your industry and for ALL toxic metals, cyanides, and total phenols. If you are not required to mark column 2-a (secondary industries, nonprocess wastewater outfalls, andnonrequired GC/MS fractions), mark "X" in column 2-b for each pollutant you know or have reason to believe is present. Mark "X" in column 2-c for each pollutant you believe is absent. If you mark column 2a for any pollutant, you must provide the results of at least one analysis for that pollutant. If you mark column 2b for any pollutant, you must provide the results of at least one analysis for that pollutant if youknow or have reason to believe it will be discharged in concentrations of 10 ppb or greater. If you mark column 2b for acrolein, acrylonitrile, 2,4 dinitrophenol, or 2-methyl-4, 6 dinitrophenol, you must provide the results of at least one analysis for each of these pollutants which you know or have reason to believe that you discharge in concentrations of 100 ppb or greater. Otherwise for pollutants for which you mark column 2b, you must either submit at least one analysis or briefly describe the reasons the pollutant is expected to be discharged. Note that there are 7 pages to this part; please review each carefully.

Complete one table (all 7 pages) for each outfall. See instructions for additional details and requirements.1. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONMETALS, CYANIDE, AND TOTAL PHENOLS1M. Antimony,Total (7440-36-0)X<0.0021mg/L<0.00212M. Arsenic, Total(7440-38-2)X<0.0051mg/L<0.00513M. Beryllium,Total, (7440-41-7)X<0.00051mg/L<0.000514M. Cadmium, Total (7440-43-9)X<0.00011mg/L<0.000115M. Chromium, Total (7440-47-3)X<0.0031mg/L<0.00316M. Copper, Total(7440-50-8)X0.002241mg/L<0.00117M. Lead, Total (7439-92-1)X<0.0021mg/L<0.00218M. Mercury, Total(7439-97-6)X0.000001031mg/L19M. Nickel, Total (7440-02-0)X<0.0021mg/L<0.002110M. Selenium, Total (7782-49-2)X<0.0051mg/L<0.005111M. Silver, Total (7440-22-4)X<0.0011mg/L<0.001112M. Thallium, Total (7440-28-0)X<0.00051mg/L<0.0005113M. Zinc, Total (7440-66-6)X<0.0101mg/L<0.010114M. Cyanide,Total (57-12-5)X<0.0051mg/L<0.005115M. Phenols, TotalX<0.0051mg/L<0.0051DIOXIN2,3,7,8-Tetra-DESCRIBE RESULTSchlorodibenzo-PXDioxin (1764-01-6)0.00000169TN5640020504103EPA Form 3510-2C (8-90)Page V-3CONTINUE ON PAGE V-4 CONTINUED FROM PAGE V-31. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - VOLATILE COMPOUNDS1V. Acrolein(107-02-8)X<0.0051mg/L<0.00512V. Acrylonitrile(107-13-1)X<0.0051mg/L<0.00513V. Benzene (71-43-2)X<0.0011mg/L<0.00114V.Bis(Chloro-methyl) EtherX**(542-88-1)5V. Bromoform (75-25-2)X<0.0011mg/L<0.00116V. Carbon TetrachlorideX<0.0011mg/L<0.0011(56-23-5)7V. Chlorobenzene(108-90-7)X<0.0011mg/L<0.00118V. Chlorodi-bromomethaneX<0.0011mg/L<0.0011(124-48-1)9V. Chloroethane (75-00-3)X<0.0011mg/L<0.001110V. 2-Chloro-ethylvinyl EtherX<0.0051mg/L<0.0051(110-75-8)11V. Chloroform (67-66-3)X<0.0011mg/L<0.001112V. Dichloro-bromomethaneX<0.0011mg/L<0.0011(75-27-4)13V. Dichloro-difluoromethaneX*<0.0011mg/L<0.0011(75-71-8)14V. 1,1-Dichloro-ethane (75-34-3)X<0.0011mg/L<0.001115V. 1,2-Dichloro-ethane (107-06-2)X<0.0011mg/L<0.001116V. 1,1-Dichloro-ethylene (75-35-4)X<0.0011mg/L<0.001117V. 1,2-Dichloro-propane (78-87-5)X<0.0011mg/L<0.001118V. 1,3-Dichloro-propylene (542-75-6)X<0.0021mg/L<0.002119V. Ethylbenzene(100-41-4)X<0.0011mg/L<0.001120V. MethylBromide (74-83-9)X<0.0011mg/L<0.001121V. MethylChloride (74-87-3)X<0.0011mg/L<0.0011* NOTE: Bis (Chloro-methyl) Ether and Dichloro-difluoromethane were removed as requirements from 40 CFR Part 123 by US EPA in 1995.EPA Form 3510-2C (8-90)Page V-4CONTINUE ON PAGE V-5 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE V-41. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - VOLATILE COMPOUNDS (continued)22V. MethyleneChloride (75-09-2)X<0.0021mg/L<0.002123V. 1,1,2,2-Tetra-chloroethaneX<0.0011mg/L<0.0011(79-34-5)24V. Tetrachloro-ethylene (127-18-4)X<0.0011mg/L<0.001125V. Toluene(108-88-3)X<0.0011mg/L<0.001126V. 1,2-Trans-Dichloroethylene X<0.0011mg/L<0.0011(156-60-5)27V. 1,1,1-Tri-chloroethaneX<0.0011mg/L<0.0011(71-55-6)28V. 1,1,2-Tri-chloroethaneX<0.0011mg/L<0.0011(79-00-5)29V. Trichloro-ethylene (79-01-6)X<0.0011mg/L<0.001130V. Trichloro-fluoromethane X*<0.0011mg/L<0.0011(75-69-4)31V. VinylChloride (75-01-4)X<0.0011mg/L<0.0011GC/MS FRACTION - ACID COMPOUNDS1A. 2-Chloropheno(95-57-8)X<0.0101mg/L<0.01012A. 2,4-Dichloro-phenol (120-83-2)X<0.0101mg/L<0.01013A. 2,4-Dimethyl-phenol (105-67-9)X<0.0101mg/L<0.01014A. 4,6-Dinitro-O-Cresol (534-52-1)X<0.0101mg/L<0.01015A. 2,4-Dinitro-phenol (51-28-5)X<0.0201mg/L<0.02016A. 2-Nitrophenol(88-75-5)X<0.0101mg/L<0.01017A. 4-Nitrophenol(100-02-7)X<0.0101mg/L<0.01018A. P-Chloro-MCresol (59-50-7)X<0.0101mg/L<0.01019A. Pentachloro-phenol (87-86-5)X<0.0101mg/L<0.010110A. Phenol(108-95-2)X<0.0101mg/L<0.010111A. 2,4,6-Trichloro-phenol (88-06-2)X<0.0101mg/L<0.0101* NOTE: Trichlorofluoromethane was removed as a requirement from 40 CFR Part 123 by US EPA in 1995.TN5640020504103EPA Form 3510-2C (8-90)Page V-5CONTINUE ON PAGE V-6 CONTINUED FROM PAGE V-51. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS1B. Acenaphthene(83-32-9)X2B. Acenaphtylene(208-96-8)X3B. Anthracene(120-12-7)X4B. Benzidine (92-87-5)X 5B.Benzo(a)AnthraceneX(56-55-3)6B.Benzo(a)Pyrene (50-32-8)X 7B. 3,4-Benzo-fluorantheneX(205-99-2)8B. Benzo (ghi)PeryleneX(191-24-2)9B.Benzo(k)FluorantheneX(207-08-9)10B.Bis(2-Chloro-ethoxy) MethaneX(111-91-1)11B.Bis(2-Chloro-ethyl) EtherX(111-44-4)12B.Bis(2-Chloro-isopropyl) Ether X(102-60-1)13B. Bis (2-Ethyl-hexyl) PhthalateX(117-81-7)14B. 4-Bromo-phenyl PhenylXEther (101-55-3)15B. Butyl BenzylPhthalate (85-68-7)X16B. 2-Chloro-naphthaleneX(91-58-7)17B. 4-Chloro-phenyl PhenylXEther (7005-72-3)18B. Chrysene(218-01-9)X19B.Dibenzo(a,h)AnthraceneX(53-70-3)20B. 1,2-Dichloro-benzene (95-50-1)X<0.0011mg/L<0.001121B. 1,3-Dichloro-benzene (541-73-1)X<0.0011mg/L<0.0011EPA Form 3510-2C (8-90)Page V-6CONTINUE ON PAGE V-7 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE V-61. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS (continued)22B. 1,4-Dichloro-benzene (106-46-7)X<0.0011mg/L<0.001123B. 3,3'-Dichloro-benzidineX(91-94-1)24B. DiethylPhthalateX(84-66-2)25B. DimethylPhthalateX(131-11-3)26B. Di-N-ButylPhthalateX(84-74-2)27B. 2,4-Dinitro-toluene (121-14-2)X 28B. 2,6-Dinitro-toluene (606-20-2)X 29B. Di-N-OctylPhthalateX(117-84-0)30B. 1,2-Diphenyl-hydrazine (as Azo-Xbenzene)(122-66-7)31B. Fluoranthene(206-44-0)X 32B. Fluorene(86-73-7)X 33B. Hexachlorobenzene(118-74-1)X 34B. Hexa-chlorobutadieneX(87-68-3)35B. Hexachloro-cyclopentadieneX(77-47-4)36B. Hexachloro-ethane (67-72-1)X37B. Indeno(1,2,3-cd) PyreneX(193-39-5)38B. Isophorone(78-59-1)X 39B. Naphthalene(91-20-3)X40B. Nitrobenzene(98-95-3)X41B. N-Nitro-sodimethylamineX(62-75-9)42B. N-Nitrosodi-PropylamineX(621-64-7)TN5640020504103EPA Form 3510-2C (8-90)Page V-7CONTINUE ON PAGE V-8 CONTINUED FROM PAGE V-71. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFa. CONCEN-b. MASSAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-TRATION(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONGC/MS FRACTION - BASE/NEUTRAL COMPOUNDS (continued)43B. N-Nitro-sodiphenylamineX(86-30-6)44B. Phenanthrene (85-01-8)X 45B. Pyrene(129-00-0)X 46B. 1,2,4 - Tri-chlorobenzeneX<0.0011mg/L<0.0011(120-82-1)GC/MS FRACTION - PESTICIDES1P. Aldrin(309-00-2)X2P.BHC(319-84-6)X 3P.-BHC(319-85-7)X 4P.-BHC(58-89-9)X 5P.-BHC(319-86-8)X 6P. Chlordane(57-74-9)X 7P. 4,4'-DDT(50-29-3)X 8P. 4,4'-DDE(72-55-9)X 9P. 4,4'-DDD(72-54-8)X 10P. Dieldrin(60-57-1)X 11P.-Endosulfan(115-29-7)X12P.-Endosulfan(115-29-7)X 13P. EndosulfanSulfateX(1031-07-8)14P. Endrin (72-20-8)X15P. Endrin AldehydeX(7421-93-4)16P. Heptachlor(76-44-8)X EPA Form 3510-2C (8-90)Page V-8CONTINUE ON PAGE V-9 EPA I.D. NUMBER (copy from Item 1 of Form 1)OUTFALL NUMBERCONTINUED FROM PAGE V-81. POLLUTANT2. MARK 'X'3. EFFLUENT4. UNITS5. INTAKE (optional)AND CASa. TEST-b. BE-c. BE-a. MAXIMUM DAILY VALUEb. MAXIMUM 30 DAY VALUEc. LONG TERM AVRG. VALUEa. LONG TERMa. LONG TERMb. NO. OFNUMBERINGLIEVEDLIEVED(if available)(if available)d. NO. OFAVERAGE VALUEAVERAGE VALUEANAL-(if available)RE-PRE-AB-(1)(2) MASS(1)(2) MASS(1)(2) MASSANAL-a. CONCEN-b. MASS(1) CONCEN-(2) MASSYSESQUIREDSENTSENTCONCENTRATIONCONCENTRATIONCONCENTRATIONYSESTRATIONTRATIONGC/MS FRACTION - PESTICIDES (continued)17B. HeptachlorEpoxideX(1024-57-3)18P. PCB-1242(53469-21-9)X19P. PCB-1254 (11097-69-1)X20P. PCB-1221 (11104-28-2)X21P. PCB-1232 (11141-16-5)X22P. PCB-1248 (12672-29-6)X23P. PCB-1260 (11096-82-5)X24P. PCB-1016 (12674-11-2)X25P. Toxaphene(8001-35-2)XTN5640020504103EPA Form 3510-2C (8-90)Page V-9 42.320ERCW Intake40.306ERCW Screen & Strainer BackwashCCWDischarge0.014Outfall 117Intake Forebay1447.871CCW Trash Sluice0.006Outfall 116Tennessee RiverCondenserCooling(INACTIVE)Outfall 118Dredge PondOutfall 110DP1447.014Raw WaterTreatmentCond. Circulating WaterRaw Cooling Water Diesel fuel recover trench High Press Fire water Potable waterCooling WaterCCW Discharge Channel (DC)Helper ModeCold WaterReturn ChannelCondenser CoolingWater (CCW)Intake1447.865CondenserCirculating SystemTennesseeNS0.0241409.865Cooling Tower Blowdown BasinCooling TowersUnits 1 & 2NS0.058Closed ModeTBSCCW Discharge Channel CCS Wastewaters Primary System WasteLVP38.000e RiverLiquid RadwasteTreatment System (LRW)odoas(CTB)DCRaw Cooling WaterSystem087537.125Radioactive Floor Drain and SumpWest Valve Vault Room DrainsLaundry, Shower, and Chemical DrainsCCS Wastewater Condensate Demin. SystemWastewater0.030Low Volume WasteTreatment Pond (LVP)Diffuser Pond (DP)40.436NS0.0040.177NS0.0491447.014Neutral WasteSumpSteam Generator BlowdownERCW System Condensate Demin.System (Alt)0.050Raw WaterTreatmentRaw Service WaterSystemMiscellaneousEquipment CoolingOutfall 1011490.8540.412Water TreatmentSystem1.230IMP1070.00222.125Emergency SpillwayOutfall 101E0.875TBS0.463Makeup Water ProcesswastewatersSystem WastewaterRaw WaterLeaks & DraindownsYDP1.047IMP 103pUnlined MetalCleaningWaste PondLined MetalCleaningWaste PondNSTreatmentTurbine Building Sump (TBS)Yard DrainagePond (YDP)System1.047Process wastewatersFilter Backwash andWTP WastewatersMake-up Water(DWST)Component CoolingSystemTBS0.0300.004Primary SystemCCS WastewaterLRWDPNS0.0061DCYDP2.119TBS0.0300.202Condensate DeminSystemSystemSteam Generator Fill0.180Steam GeneratorBlowdownSecondary System0.030CTBLRWSecondary SystemLeaks&DowndrainsMiscellaneous Low Volume Wastewater & Yard DrainageService Building SumpOffice Bldg Floor & Equip Drains Diesel Gen Bldg Sump & O&G Interceptor (o/w separator)Backup Security Diesel O&G Interceptor (o/w separator)Solar Bldg Sump Air Cooling Water Switchyard Bus Cooling Water Miscellaneous line leaks, flushesand draindownsERCWtitdidMiscellaneous Low Volume WastewatersMiscellaneous Equipment Cooling WaterEssential Raw Cooling Water Maintenance DraindownComponent Cooling SystemWastewaterProcess waters and wastewaters Steam Generator Blowdown Condensate DeminRegenWaste Secondary System leaks andDraindownsTennessee Valley AuthorityShNlPltCondensate DeminRegeneration WasteSystem0.1000.022Negligible flow nLeaks & DowndrainsTBSERCW system maint. draindownsElectrical Sumps East Valve Vault Room drains Pressure washing & vehicle rinses Switchyard stormwater runoff Landfill RunoffIce Condenser waste Laboratory wastewaters Turbine Building floor andEquipment drainsAlum Sludge PondCTBDCCCW Discharge ChannelCooling Tower BasinSequoyah Nuclear PlantWastewater Flow SchematicNPDES Permit No. TN0026450April 2013All flows shown in million gallons per day (MGD)Alternate pathChemical Additive Net Stormwater Flow (runoff, precipitation, less evaporation)NSDPTBSLRWLVPYDPLiquid RadwasteTreatment SystemTurbine Building SumpLow Volume Waste Treatment PondYard Discharge PondDiffuser Pond CN-1090 (rev. 04-2007) RDAs 2352 AND 2366 Tennessee Department of Environment and Conservation Division of Water Pollution Control 401 Church Street, 6th Floor L & C Annex Nashville, TN 37243-1534 Phone: (615)532-0625 PERMIT CONTACT INFORMATION Please complete all sections. If one person serves multiple functions, please repeat this information in each section. PERMIT NUMBER: TN0026450 DATE: April 2013 PERMITTED FACILITY: TVA Sequoyah Nuclear Plant COUNTY: Hamilton (The permit signatory authority, e.g. responsible corporate officer, principle executive officer or ranking elected official) John T. Carlin Site Vice President Sequoyah Acess Road, PO Box 2000 Soddy Daisy TN 37379 (423) 843-7001 jtcarlin@tva.gov Brad M. Love Environmental Scientist Sequoyah Acess Road, PO Box 2000 Soddy Daisy TN 37379 (423) 843-6714 bmlove@tva.gov Brad M. Love Environmental Scientist Seqouyah Access Road Soddy Daisy TN 37379 (423) 843-6714 bmlove@tva.gov Yes No* . OFFICIAL PERMIT CONTACT: Official Contact:Title or Position:PERMIT BILLING ADDRESS (where invoices should be sent): Billing Contact: Phone number(s):Title or Position:Mailing Address:City:State:Zip:E-mail:FACILITY LOCATION (actual location of permit site and local contact for site activity): Facility Location Contact:Phone number(s):Title or Position:Facility Location (physical street address):City:State:Zip:E-mail:Alternate Contact (if desired): Phone number(s):Title or Position:Mailing Address:City:State:Zip:E-mail:FACILITY REPORTING (Discharge Monitoring Report (DMR) or other reporting): Mailing Address:City:State:Zip:E-mail:Phone number(s):Cognizant Official authorized for permit reporting:Phone number(s):E-mail:Fax number for reporting:Does the facility have interest in starting electronic DMR reporting?* Facility Location (physical street address):City:State:Zip:Title or Position:

TENNESSEE VALLEY AUTHORITY (TVA) - SEQUOYAH NUCLEAR PLANT (SQN) - NPDES PERMIT NO. TN0026450 - WET REASONABLE POTENTIAL Current Whole Effluent Toxicity (WET) Requirements: Outfall 101 - 7-day or 3-brood IC25 Hard Trigger = 43.2% [IWC = 43.2% effluent (2.3 TUc)] Monitoring Frequency Governed by B/CTP:

1/year when oxidizing biocides used 1/year when non-oxidizing biocides used Proposed WET Requirements: Outfall 101 - 7-day or 3-brood IC25 Hard Trigger = 42.8% [IWC = 42.8% effluent (2.3 TUc)] Monitoring Frequency Governed by B/CTP:

1/year when oxidizing biocides used 1/year when non-oxidizing biocides used Background: The current permit, effective March 1, 2011, requires chronic toxicity biomonitoring at a frequency governed by the B/CTP and with a monitoring limit (IC25 43.2%) that serves as a hard trigger for accelerated biomonitoring. Previous to the issuance of the current permit, Outfall 101 demonstrated No Reasonable Potential for excursions above the ambient water quality chronic (CCC) criterion using historical effluent data. This demonstration of No Reasonable Potential has been maintained throughout the current permit cycle as evidenced in the accompanying historical effluent data for the last 20 studies.

Based on guidance in EPA's Technical Support Document (TSD) for Water Quality-based Toxics Control (EPA/505/2-90-001), a permit limit is not required when No Reasonable Potential exists for excursions above the CCC. In this situation, the TSD recommends that biomonitoring be conducted at a frequency of once every 5 years as part of the permit renewal process.

Proposed Changes: 1. TVA requests that the current permit's requirement for the B/CTP to govern the frequency of biomonitoring remain (i.e., once per year when oxidizing biocides are used, and once per year when non-oxidizing biocides are used).

2. TVA requests that the current monitoring limit be replaced with an IC25 = 42.8%, which is based on revised effluent flow, and is consistent with the TSD guidance for effluents demonstrating No Reasonable Potential. Toxicity at the instream wastewater concentration (IWC) would serve only as a hard trigger for accelerated biomonitoring, as stated in the current permit.

2 3. TVA requests changes to the Serial Dilutions table as follows: Page 22 of 28, table following paragraph 3:

4. TVA also requests that all other text in Section E of the permit remain unchanged.

Dilution and Instream Waste Concentration Calculations Outfall 101:

Average Discharge = 1491 MGD

Tennessee River 1Q10 = 3483 MGD Dilution Factor (DF): 34.214913483QwQsDF Instream Wastewater Concentration (IWC): %8.42100x34831491QsQwIWC Reasonable Potential Determination:

The last 20 studies for Outfall 101 were used for determining Reasonable Potential, with all studies resulting in no observed toxicity (<1.0 TUc) and a coefficient of variation equal to zero. This outcome demonstrates that no Reasonable Potential for excursions above the CCC exists, based on data obtained from testing conducted under the current operating conditions. Historical data for the last 20 studies follows, and is followed thereafter with documentation of chemical additions which occurred during sampling for toxicity tests for Outfall 101.

Serial Dilutions for Whole Effluent Toxicity (WET) Testing 100% Effluent (100+ML)/2 Monitoring Limit (ML) 0.5 X ML O.25 X ML Control % effluent 100 71.4 42.8 21.4 10.7 0 3SQN Documentation: Summary of SQN Outfall 101 WET Biomonitoring Results ** Acute Results (96-h Survival) Chronic Results

Test Date

Test Species % Survival in Undiluted Sample Study Toxicity Units (TUa) Study Toxicity Units (TUc) 64. Feb 8-15, 2005 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 93 65. Jun 7-14, 2005 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 66. Jul 19-26, 2005 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 67. Nov 1-8, 2005 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 68. Nov 16-23, 2005 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 98 69. Nov 14-21, 2006 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 70. Nov 28 - Dec 5, 2006 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 98 71. May 30- Jun 6, 2007 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 72. Dec 4-11, 2007 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 73. Apr 15-22, 2008 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 93 74. Oct 28- Nov 4, 2008 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 98 75. Feb 10-17, 2009 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 76. May 12-19, 2009 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 98 77. Nov 17-24, 2009 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 78. May 11-18, 2010 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 79. Nov 2-9, 2010 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 80. May 3-10, 2011 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 81. Nov 8-15, 2011 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 98 82. May 8-15, 2012 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 83. Aug 12-17, 2012 Ceriodaphnia dubia 100 <1.0 <1.0 Pimephales promelas 100 n 40 20 20 Maximum 100 <1.0 <1.0 Minimum 93 <1.0 <1.0 Mean 99 <1.0 <1.0 CV 0.02 0.00 0.00 **Last 20 studies only were included for determining RP. Shaded area includes data collected under the current permit.

4Sequoyah Nuclear Plant Diffuser (Outfall 101) Discharge Concentrations of Chemicals Used to Control Microbiologically Induced Corrosion and Mollusks, During Toxicity Test Sampling November 7, 2004 - August 17, 2012 Date Sodium Hypochloritemg/L TRC Towerbrom mg/L TRC PCL-222 mg/L Phosphate PCL-401 mg/L CopolymerCL-363mg/L DMADCuprostat-PF mg/L Azole H-130M mg/L Quat Nalco 73551 mg/L EO/PO H-150Mmg/L Quat 11/07/2004 11/08/2004 11/09/2004 11/10/2004 11/11/2004 11/12/2004 - - - - - - <0.0187

<0.0192 <0.0233 <0.0149 <0.0149 <0.0253 0.000 0.047 0.048 0.047 0.049 0.048 0.014 0.030 0.016 0.016 0.017 0.017 - - - - - - - - - - - - - - - - 0.041 0.041 0.043 0.042 - - - - - - - - - - 02/06/2005 02/07/2005 02/08/2005 02/09/2005 02/10/2005 02/11/2005 - - - - - - <0.0042

<0.0116

<0.0080 0.0199 <0.0042 0.0155 0.028 0.028 0.028 0.028 0.028 0.028 0.010 0.010 0.010 0.010 0.010 0.010 - - - - - - -

-

- - -

- - - - - - - - 0.007 - - - 0.007 - - - - - - 06/05/2005 06/06/2005 06/07/2005 06/08/2005 06/09/2005 06/10/2005 - - - - - - 0.0063 0.0043 0.0103 0.0295 0.0129 0.0184 - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - 0.037 0.037 0.037 - - 07/17/2005 07/18/2005 07/19/2005 07/20/2005 07/21/2005 07/22/2005 - - - - - - 0.0109 0.0150 0.0163 0.0209 0.0242 0.0238 0.026 0.026 0.026 0.026 0.026 0.054 0.009 0.009 0.009 0.009 0.009 0.018 - - - - - - - - - -

- - - - - - - - - - - 0.014 - 0.014 - 0.036 0.036 0.036 - - 10/30/2005 10/31/2005 11/01/2005 11/02/2005 11/03/2005 11/04/2005 - - - - - - 0.0068 0.0112 0.0104 0.0104 0.0117 0.0165 - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - 0.035 0.036 0.036 0.035 11/14/2005 11/15/2005 11/16/2005 11/17/2005 11/18/2005 11/19/2005 - - - - - - 0.0274 0.0256 0.0234 0.0231 0.0200 0.0116 - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - -

5Sequoyah Nuclear Plant Diffuser (Outfall 101) Discharge Concentrations of Chemicals Used to Control Microbiologically Induced Corrosion and Mollusks, During Toxicity Test Sampling November 7, 2004 - August 17, 2012 Date Sodium Hypochloritemg/L TRC Towerbrom mg/L TRC PCL-222 mg/L PhosphatePCL-401 mg/L CopolymerCL-363mg/L DMADCuprostat-PF mg/L Azole H-130M mg/L Quat Nalco 73551 mg/L EO/PO H-150M mg/L Quat MSW 101 mg/L Phosphate11/12/2006 11/13/2006 11/14/2006 11/15/2006 11/16/2006 11/17/2006 - - - - - - 0.0055 0.0068 0.0143 0.0068 0.0267 0.0222 - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - 0.037 0.037 0.037 0.037 - -

- - - - - 11/26/2006 11/27/2006 11/28/2006 11/29/2006 11/30/2006 12/01/2006 - - - - - - 0.0188 0.0138 0.0120 0.0288 0.0376 0.0187 - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - 05/28/07 05/29/07 05/30/07 05/31/07 06/01/07 06/02/07 - - - - - - - - 0.0084 0.0103 0.0164 0.0305 - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - 0.017 - 0.017 - - 0.036 0.036 0.036 0.036 - 0.015 0.015 0.015 0.015 0.015 0.015 12/02/07 12/03/07 12/04/07 12/05/07 12/06/07 12/07/07 - - - - - - 0.0241 0.0128 0.0238 0.0158 0.0162 0.0175 - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - 04/13/08 04/14/08 04/15/08 04/16/08 04/17/08 04/18/08 - - - - - - 0.0039 0.0124 0.0229 0.0143 0.0120 0.0149 - - - - - - -

-

- - -

- - - - - - - -

-

- - -

- - - - - - - -

-

- - -

- - - - - - - -

-

- - -

- 10/26/08 10/27/08 10/28/08 10/29/08 10/30/08 10/31/08 - - - - - - 0.0260 0.0151 0.0172 0.0154 - 0.0086 - - - - - - - -

- - -

- - - - - - - -

-

- - -

- - - - - - - - 0.017 - 0.018 -

- - - 0.041 0.041 0.041 0.041 -

-

- 0.030 0.030 0.030

6Sequoyah Nuclear Plant Diffuser (Outfall 101) Discharge Concentrations of Chemicals Used to Control Microbiologically Induced Corrosion and Mollusks, During Toxicity Test Sampling November 7, 2004 - August 17, 2012 Date Sodium Hypochloritemg/L TRC Towerbrom mg/L TRC PCL-222 mg/L Phosphate PCL-401 mg/L CopolymerCL-363 mg/L DMADCuprostat-PF mg/L Azole H-130Mmg/L Quat Nalco 73551 mg/L EO/PO Spectrus CT1300 mg/L Quat H-150M mg/L Quat MSW 101 mg/L Phosphate02/08/09 02/09/09 02/10/09 02/11/09 02/12/09 02/13/09 - - - - - - 0.0197 0.0237 0.0104 0.0155 0.0106 - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - 0.017 0.017 0.021 0.017 0.017 - - - - - - - - - - - - - - - - - - - 05/10/09 05/11/09 05/12/09 05/13/09 05/14/09 05/15/09 - - - - - - 0.0129 0.0415 0.0053 0.0049 <0.0141 <0.0160 - - - - - - -

-

- - -

- - - - - - - -

-

- - -

- - - - - - - -

-

- - -

- - - - - - - - 0.0446 0.0396 0.0396 0.0397 - -

-

- - -

- 11/15/09 11/16/09 11/17/09 11/18/09 11/19/09 11/20/09 - - - - - - 0.025 0.0152 0.0255 0.0306 0.0204 0.0093 - - - - - - -

- - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - - - - - - - -

- - - - - 05/09/10 05/10/10 05/11/10 05/12/10 05/13/10 05/14/10 - - - - - - 0.0192 0.0055 0.0100 0.0171 0.0041 0.0099 - - - - - - -

-

- - -

- - - - - - -

-

- - -

- - - - - - - -

-

- - -

- - - 0.039 0.039 0.039 0.039 - - - - - - -

-

- - -

-

7Sequoyah Nuclear Plant Diffuser (Outfall 101) Discharge Concentrations of Chemicals Used to Control Microbiologically Induced Corrosion and Mollusks, During Toxicity Test Sampling November 7, 2004 - August 17, 2012 Date Sodium Hypochlorite mg/L TRC Towerbrom mg/L TRC PCL-222 mg/L Phos-phate PCL-401 mg/L Copolymer CL-363 mg/L DMAD Cuprostat-PF mg/L Azole H-130Mmg/L Quat Nalco 73551 mg/L EO/PO Spectrus CT1300 mg/L Quat H-150M mg/L Quat MSW 101 mg/L PhosphateFloguard MS6236 mg/L Phosphate10/31/10 11/01/10 11/02/10 11/03/10 11/04/10 11/05/10 - - - - - - - 0.0122 0.0112 0.0163 0.0107 0.0132 - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - - - - - - - -

- - - - - -

- - - 05/01/2011 05/02/2011 05/03/2011 05/04/2011 05/05/2011 05/06/2011 - - - - - - -

- - 0.0155 0.0179 0.0089 - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - 0.04 0.04 0.04 0.04 - - - - - - - -

- - - - - -

- - - - - 11/06/2011 11/07/2011 11/08/2011 11/09/2011 11/10/2011 11/11/2011 - - - - - - 0.0168 0.0225 0.0141 0.0239 0.0242 0.0231 - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - - - - - - - -

- - - - - -

- - - - - 05/06/2012 05/07/2012 05/08/2012 05/09/2012 05/10/2012 05/11/2012 - - - - - - - - - 0.0145 0.0298 0.0174 - - - - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - -

- - - - 0.041 0.041 0.041 - - - - - - - - - - -

- - - - - -

- - 08/12/2012 08/13/2012 08/14/2012 08/15/2012 08/16/2012 08/17/2012 - - - - - - - 0.0256 0.0209 0.0279 0.0076 0.0446 - - - - - - -

- - - - - - - - - - - -

- - - - - - - - - - - - 0.028 - 0.028 -

- - 0.037 0.037 - - - - - - - - - -

- - - - - 0.029 0.029 0.029 0.029 0.029 0.032

Study Plan for Evaluation of the TVA Sequoyah Nuclear Plant Discharge in Support of an Alternate Thermal Limit Soddy Daisy, Hamilton County, Tennessee Tennessee Valley Authority June 8, 2011 i TABLEOFCONTENTS EXECUTIVE SUMMARY ............................................................................................. iii1.0INTRODUCTION ................................................................................................. 11.1Facility Information .......................................................................................... 11.2Regulatory Basis ............................................................................................... 11.2.1Applicable Thermal Criteria ....................................................................... 11.2.2Permitted Conditions .................................................................................. 21.2.3Criteria for Alternate Thermal Limits Under §316(a) ................................ 21.2.4Mixing Zone Requirements in Tennessee Rule 1200-4-3-0.5 .................... 41.3Study Plan Organization ................................................................................... 52.0STUDY BACKGROUND ..................................................................................... 52.1Sequoyah Nuclear Plant .................................................................................... 52.2Description of the Receiving Waterbody ......................................................... 52.3Previous §316(a) Demonstration Study ............................................................ 62.4Contemporary Studies ...................................................................................... 73.0STUDY PLAN ....................................................................................................... 83.1Study Timing .................................................................................................... 83.2Study Scope ...................................................................................................... 8Task 1 - Evaluate Plant Operating Conditions ......................................................... 8Task 2 - Thermal Plume Monitoring and Mapping ................................................. 9Task 3 - Establishment of Biological Sampling Stations ....................................... 10Task 4 - Shoreline and River Bottom Habitat Characterization ............................ 10Task 5 - Supporting Water Quality Measurements ................................................ 11Task 6 - Biological Evaluations ............................................................................. 11Task 7 -Water Supply and Recreational Use Support Evaluation ......................... 143.3Data Contribution to the Analysis/Demonstration ......................................... 143.3.1Traditional Analyses ................................................................................. 143.3.2Supporting Multi-metric Bioassessment ................................................... 153.3.4Reasonable Potential Evaluation .............................................................. 163.4Reporting ........................................................................................................ 163.5Study Schedule Summary ............................................................................... 164.0LITERATURE CITED ........................................................................................ 18 ii LISTOFFIGURES Figure 1. Vicinity map for Sequoyah Nuclear plant depicting Chickamauga and Watts Bar Dam locations and water supply intakes downstream of the plant thermal discharge ........................................................................................................................................ 20Figure 2. Site map for Sequoyah Nuclear plant showing condenser cooling water intake structure, skimmer wall, and NPDES-permitted discharge Outfall No. 101 .................. 21Figure 3. Biological monitoring zone downstream of Sequoyah Nuclear plant ............. 22Figure 4. Biological monitoring zone upstream of Sequoyah Nuclear plant thermal discharge ......................................................................................................................... 23Figure 5. Anticipated transects to be established for conduct of the integrative multi-metric aquatic shoreline habitat assessment ................................................................... 24 iii EXECUTIVESUMMARYThis document sets forth a revised Study Plan, which the Tennessee Valley Authority (TVA) plans to implement for the purpose of evaluating the Sequoyah Nuclear Plant (SQN) thermal discharge in support of compliance with the National Pollutant Discharge Elimination System (NPDES) permit for the facility and continuance of the associated Alternate Thermal Limit (ATL) for Outfall 101 as authorized under Section 316(a) of Clean Water Act and Tennessee Department of Environment and Conservation rules. As required by the NPDES permit, the Study Plan was first submitted to the Tennessee Department of Environment and Conservation (TDEC) on December 20, 2010 and subject to review by TDEC and the U. S. Environmental Protection Agency (EPA), Region 4. Comments and suggested revisions were provided to TVA by TDEC in a meeting held on April 7, 2011 and have been incorporated herein.

The Study Plan provides regulatory background for the work; information about SQN operations; a brief description of the receiving waterbody; a summary of previous §316(a) and more recent monitoring studies conducted at the plant; and a detailed Scope of Work proposing the collection of new data to evaluate the potential impact of the Sequoyah Nuclear thermal discharge on the aquatic life and other classified uses of the Tennessee River/Chickamauga Reservoir in the vicinity of the plant. Specifically, studies are proposed to: 1. Collect the temperature data needed to delineate and map the spatial boundaries of the thermal discharge plume; 2. Characterize the aquatic and wildlife habitat in the study area; 3. Sample the fish, macroinvertebrate, and plankton communities; 4. Survey potentially affected wildlife; 5. Evaluate maintenance of a balanced indigenous population (BIP) by performing traditional and multi-metric analyses of collected data, as appropriate; and 6. Evaluate the reasonable potential for impairment of non-aquatic life uses of the receiving waterbody as they relate to the thermal discharge. Field sampling activities are scheduled to begin in the summer and autumn of 2011. Resultant information will be used to support renewal of the facility's NPDES permit set to expire October 31, 2013.

1 1.0INTRODUCTIONThis document sets forth a revised Study Plan, which the Tennessee Valley Authority (TVA) plans to implement for the purpose of evaluating the Sequoyah Nuclear Plant (SQN) thermal discharge in support of compliance with the National Pollutant Discharge Elimination System (NPDES) permit for the facility (NPDES Permit No.: TN0026450). The Study Plan includes a review and discussion of applicable regulatory requirements for the thermal discharge and presents specific work elements for the re-verification of the existing Alternate Thermal Limit (ATL) for Outfall 101 in accordance with Clean Water Act (CWA) Section (§) 316(a). As required by the NPDES permit, the Study Plan was first submitted to the Tennessee Department of Environment and Conservation (TDEC) on December 20, 2010 and subject to review by TDEC and the U. S. Environmental Protection Agency (EPA), Region 4. Comments and suggested revisions were provided to TVA by TDEC in a meeting held on April 7, 2011 and have been incorporated herein. 1.1FacilityInformationUnit 1 and 2 were placed in operation in 1981 and 1982, respectively. Both units can produce more than 2,400 megawatts of electricity. SQN is located on the right descending bank of the Tennessee River (Chickamauga Reservoir) near Chattanooga, Tennessee (Figure 1). The facility withdraws cooling water from Chickamauga Reservoir via an intake channel and skimmer wall at river mile (TRM) 484.8. The cooling water intake structure (supporting six circulator pumps) provides the units a nominal flow of 1.11 x 106 gallons per minute (gpm) or 1,602 million gallons per day (mgd). The facility employs a once-through (open cycle) condenser cooling water system and can also operate with cooling towers in helper mode. The plant discharges heated effluent to Chickamauga Reservoir via Outfall 101 located at TRM 483.6 as authorized by the NPDES permit (Figure 2). 1.2RegulatoryBasis1.2.1ApplicableThermalCriteriaTDEC has specified "use classifications" for the state's surface waters and developed temperature criteria intended to support those uses (TDEC Rule 1200-4-4 and 1200-4-3-.03, respectively). The Tennessee River at the location of SQN has been classified for the following uses: Municipal, Industrial, and Domestic Water Supply, Industrial Water Supply, Fish and Aquatic Life, Recreation, Irrigation, Livestock Watering and Wildlife, and Navigation. Except for Irrigation and Livestock Watering and Wildlife (qualitative criteria), temperature criteria relevant to warm-water conditions of the Tennessee River at SQN specify that: "The maximum water temperature change shall not exceed 3°C [5.4°F] relative to an upstream control point. The temperature of the water shall not exceed 30.5°C [86.9°F] and the maximum 2 rate of change shall not exceed 2°C [3.6°F] per hour. The temperature of impoundments where stratification occurs will be measured at a depth of 5 feet, or mid-depth whichever is less, and the temperature in flowing streams shall be measured at mid-depth." [Rule 1200-4-3-.03] The SQN plant's "once-through" cooling water system design utilizing cooling towers in helper mode provides for the most thermodynamically efficient method of generating electricity and as a result produces a heated discharge. As such, the thermal discharge typically exceeds TDEC's established temperature criteria, therefore, multiport diffusers with mixing zone are used to adequately mix the thermal effluent to meet the state water quality standard at the end of the mixing zone. In such cases, the TDEC rules specific to the Fish and Aquatic Life use classification provide that: "A successful demonstration as determined by the state conducted for thermal discharge limitations under Section 316(a) of the Clean Water Act, (33 U.S.C. §1326), shall constitute compliance- [with the temperature criteria]." TVA has previously made such successful demonstration for the SQN thermal discharge in support of mixing zone criteria as further discussed below. 1.2.2PermittedConditionsCurrently permitted thermal discharge limitations for SQN specify that the daily maximum temperature is not to exceed 30.5°C (86.9°F) at the end of the mixing zone (Page 1 of 28), NPDES permit TN0026450). This mixing zone criteria are based on a previous demonstration by TVA, in accordance with CWA §316(a) and TDEC Rule 1200-4-3-.03 noted above, that a balanced indigenous population (BIP) of fish, shellfish, and wildlife is supported in the Tennessee River potentially affected by the thermal discharge. The mixing zone criteria, as supported by the biological studies, also encompass other components of the TDEC temperature criteria, specifically the change in temperature from ambient/upstream conditions and rate of change in temperature. SQN has maintained a good compliance record with its mixing zone criteria throughout each NPDES permit term since first authorized in the late-1980s; ongoing biological monitoring has consistently demonstrated the mixing zone criteria are protective of aquatic communities in the river near the facility. 1.2.3CriteriaforAlternateThermalLimitsUnder§316(a)The regulatory provisions that implement CWA §316(a) provide limited guidance on precisely what the demonstration study must contain to be considered adequate and do not identify precise criteria against which to measure whether a "balanced and indigenous" aquatic community is protected and maintained. Instead, the regulations provide broad guidelines. Under the broad regulatory guidelines, the discharger must show that the ATL desired, "considering the cumulative impact of its thermal discharge together with all other significant impacts on the species affected," will "assure the protection and propagation of a balanced, indigenous community of shellfish, fish and wildlife in and on the body of water into which the 3 discharge is to be made (40 CFR §125.73). Critical to the demonstration is the meaning of the term "balanced indigenous community". The rules provide the following definition: "The term "balanced indigenous community" is synonymous with the term balanced, indigenous population (i.e., BIP) in the Act and means a biotic community typically characterized by diversity, the capacity to sustain itself through cyclic seasonal changes, presence of necessary food chain species and by a lack of domination by pollution tolerant species. Such a community may include historically non-native species introduced in connection with a program of wildlife management and species whose presence or abundance results from substantial, irreversible environmental modifications" (40 CFR §125.73). Pursuant to this regulatory definition, a successful demonstration must show that under the desired ATL, and in light of the cumulative impact of the thermal discharge together with all other significant impacts on the species affected, the following characteristics, which are indicative of a BIP, will continue to exist: (1) diversity, (2) the capacity of the community to sustain itself through cyclic seasonal changes, (3) presence of necessary food chain species, and (4) a lack of domination by pollution tolerant species. There are several methodologies a discharger may pursue in making a §316(a) demonstration. Under the regulations, new dischargers must use predictive methods (e.g., laboratory studies, literature surveys, or modeling) to estimate an appropriate ATL that will assure the protection and propagation of a balanced, indigenous community prior to commencing the thermal discharge. However, existing dischargers, such as SQN, need not use predictive methods. For such dischargers, §316(a) demonstrations may be based upon the "absence of prior appreciable harm" to a balanced, indigenous community (see 40 CFR §125.73(c)(1)(i) and (ii)). Such demonstrations must show either that: i) No appreciable harm has resulted from the thermal component of the discharge taking into account the interaction of such thermal component with other pollutants and the additive effect of other thermal sources to a balanced, indigenous community of shellfish, fish, and wildlife in and on the body of water into which the discharge has been made; or ii) Despite the occurrence of such previous harm, the desired alternative effluent limitations (or appropriate modifications thereof) will nevertheless assure the protection and propagation of a balanced, indigenous community of shellfish, fish, and wildlife in and on the body of water into which the discharge is made. Furthermore, in determining whether or not prior appreciable harm has occurred, the regulations provide that the permitting agency consider the length of time during which the applicant has been discharging and the nature of the discharge. The regulations do not define "prior appreciable harm." However, using the definition of "balanced, indigenous community," mixing zone criteria are generally granted under either of the following circumstances:

4 1. When a discharger shows that the characteristics of a BIP (i.e., diversity, the capacity to sustain itself through cyclic seasonal changes, presence of necessary food chain species, and a lack of domination by pollution tolerant species) exist. Stated another way, the existence of such characteristics essentially prove that the aquatic community has not been appreciably harmed; or 2. Despite any evidence of previous harm, the characteristics of a BIP, as stated above, will nevertheless be protected and assured under the alternate limit. 1.2.4MixingZoneRequirementsinTennesseeRule1200430.5As noted above, §316(a) pertains to the Fish and Aquatic Life use classification and provides NPDES-permitted facilities a regulatory compliant means of demonstrating that promulgated temperature criteria may be more stringent than necessary to support a BIP. In such cases, less stringent thermal criteria (i.e., ATLs) are justified. However, other use classifications such as Domestic Water Supply and Recreation must be protected as well. Compliance with TDEC temperature criteria for these uses is typically determined after the discharge has had the opportunity to mix with the receiving water; that is, an allowable mixing zone is determined. TDEC rules define the mixing zone as: "That section of a flowing stream or impounded waters in the immediate vicinity of an outfall where an effluent becomes dispersed and mixed." [1200-4-3-.04(8)] The rules [1200-4-3-.05(2)] further provide that mixing zones are to be restricted in area and length and not: 1. prevent the free passage of fish or cause aquatic life mortality in the receiving waters; 2. contain materials in concentrations that exceed acute criteria beyond the zone immediately surrounding the outfall; 3. result in offensive conditions; 4. produce undesirable aquatic life or result in dominance of a nuisance species; 5. endanger the public health or welfare; or 6. adversely affect the reasonable and necessary uses of the area; 7. create a condition of chronic toxicity beyond the edge of the mixing zone; 8. adversely affect nursery and spawning areas; or 9. adversely affect species with special state or federal status. While TVA's proposed §316(a) demonstration study plan fully examines the effects of the thermal discharge on the aquatic life components of the mixing zone requirements, the potential effects to other non-aquatic life use classifications (items 3, 5, and 6 above) are generally not evaluated. Therefore, this plan has been revised herein to incorporate and/or collect additional 5 information needed to address the reasonable potential for impairment of other non-aquatic life uses in the Tennessee River near the facility. 1.3StudyPlanOrganization This Study Plan is organized into the following sections: 1. Introductory information, including regulatory basis and rationale for the study; 2. Background information, including a summary of the findings of the previous §316(a) investigation and subsequent biological monitoring; and, 3. The proposed design and implementation schedule for the SQN §316(a) demonstration Study Plan. 2.0STUDYBACKGROUND2.1SequoyahNuclearPlantThe SQN facility is operated to produce base-load electric power throughout the year. When operating at design (nameplate) capacity (2,400 MW), the units requires approximately 1,602 million gallons per day of condenser cooling water. Waste heat increases the temperature of the cooling water by approximately 16.4°C (29.5°F) before it is discharged into the river. The actual condenser flow, and hence the T, may vary somewhat with the circulating water pump head and the condenser efficiency. 2.2DescriptionoftheReceivingWaterbodySequoyah Nuclear is located on the right descending bank of Chickamauga Reservoir (TRM 484.5) approximately 18 miles northeast of Chattanooga, Tennessee, and 7 miles southwest of Soddy-Daisy, Tennessee (Figure 1). Chickamauga Reservoir was impounded in 1940 and at full pool covers approximately 36,240 acres. The topography of the reservoir in the vicinity of the discharge outlet consists of a shallow overbank area on the plant side which extends from TRM 484 downstream to TRM 481.8 and varies in depth from 2 to 20 ft and from 500 to 3,100 ft in width. This shallow area is bordered by a main river channel which is about 900 feet (ft) wide and approximately 60 ft deep. Along this reach there are several small, shallow embayments. The Tennessee River flow in the vicinity of SQN is controlled by releases from Watts Bar and Chickamauga Dams, and to a lesser extent Hiwassee River. SQN is situated on Chickamauga Reservoir approximately 54.5 river miles downstream from Watts Bar Dam and 13.5 river miles upstream from Chickamauga Dam.

6 2.3Previous§316(a)DemonstrationStudyTVA conducted comprehensive §316(a) demonstration-related studies of the SQN thermal effluent in the mid-1980s to support establishment of the current mixing zone criteria for the plant discharge (TVA, 1989). The minimum average daily flow for the Tennessee River near SQN at the time of the early studies was 6,000 cfs. The mid-1980s studies included extensive sampling of the aquatic community including: Phytoplankton, Periphyton, Aquatic macrophytes, Zooplankton, Benthic macroinvertebrates; and Fish populations. Hydrothermal, water quality and other parameters also were evaluated. Major findings of these studies included: Average dissolved concentration in the water column was similar immediately upstream and downstream of SQN. Analysis of the data indicate that the assemblages of phytoplankton, zooplankton, and macroinvertebrates were diverse and, in general, relatively abundant. Dominance of blue-green algae was similar upstream and downstream of SQN. The phytoplankton and zooplankton communities were found to be similar, or if different, not impacted by SQN operation, at all stations during 20 of the 27 survey months when the plant was in operation. Species richness in the benthic macroinvertebrate communities during pre-operational and operational monitoring was similar. No changes were documented in the aquatic macrophyte community that reflected effects of the thermal effluent. Fish species occurrence and abundance data indicated insignificant impacts. Avoidances of the plume could not be detected for any species of fish. One study found that sauger (Sander canadensis) were not concentrated in the thermal plume during winter months nor inhibited from movement past SQN. Results of gonadal inspections indicate that the heated discharge did not adversely affect fish reproduction.

7 Other fisheries studies indicated that the thermal discharge resulted in no discernible increase in parasitism. No mortalities of threadfin shad due to cold shock following shutdown of SQN were observed or reported, and none are anticipated to occur in the future. 2.4ContemporaryStudiesMonitoring of the thermal effects of the SQN discharge on the aquatic community of the receiving waterbody has been more recently conducted by TVA after an agreement was reached with TDEC in 2001. TVA's "Vital Signs" monitoring program also provides useful information for evaluating reservoir-wide effects. Monitoring has included sampling of the fish and macroinvertebrate communities and associated collection of temperature and other water quality parameters. Results of the permit monitoring work and TVA's ongoing Vital Signs monitoring (TVA, 2011) have consistently demonstrated that fish and macroinvertebrate assemblages of Chickamauga Reservoir within and downstream of the SQN thermal discharge are similar to those of upstream locations, as well as to established mainstem reservoir reference conditions for the area. Results of the above studies notwithstanding, TVA plans to implement this Study Plan for the purpose of further evaluating the SQN thermal discharge to support continuance of the ATL for the facility discharge in accordance with CWA §316(a) and TDEC Rule 1200-4-3-.03(e).

8 3.0STUDYPLANThis §316(a) demonstration Study Plan is informed by communications with TDEC and EPA, the study design of the previous demonstration study, and TVA's ongoing river/reservoir biological monitoring programs. 3.1StudyTimingAs reasonably practicable, TVA sampling crews will coordinate with SQN facility operations staff to schedule field studies to coincide with representative conditions of maximum generation for the time period to be sampled as dictated by seasonal power demand. The additional field studies will be conducted during the period of critical environmental (thermal) conditions in summer (mid-July - August) when plant operations and ambient reservoir temperatures are at expected seasonal maximums. Summer monitoring will be conducted once during the SQN permit cycle. Data collection during this period will focus on characterization/delineation of the thermal plume and biological field investigations inclusive of thermally affected and unaffected areas. TVA will also conduct monitoring in autumn (October - mid-December) as has been occurring in previous study years. 3.2StudyScopeThe following tasks will be conducted for the SQN §316(a) demonstration Study: Task1-EvaluatePlantOperatingConditionsDuring the course of the study, SQN operational data will be recorded, compiled, and analyzed to assist in the interpretation of thermal plume characteristics and biological community information. Available historical operational data will also be compiled and analyzed to evaluate and identify any material changes in SQN operations over the most recent 5-year period that might affect the thermal plume characteristics. Parameters to be recorded during the proposed study and evaluated historically include, but are not limited to: Cooling water intake flow and water temperature; Discharge flow and water temperature; and Power generation statistics. The data will be presented in tabular and graphical formats to describe SQN operational conditions during the current study.

9 Task2-ThermalPlumeMonitoringandMappingPhysical measurements will be taken to characterize and map the SQN thermal plume concurrent with biological field sampling during the sampling events. In this manner, it is expected that the plume will be characterized under representative thermal maxima and seasonally-expected low flow conditions. Measurements will be collected during periods of high power production from SQN, as reasonably practicable, to capture maximum extent of the thermal plume under existing river flow/reservoir elevation conditions. This effort will allow general delineation of the "Primary Study Area" per the EPA (1977) draft guidance defined as the: "entire geographic area bounded annually by the locus of the 2°C above ambient surface isotherms as these isotherms are distributed throughout an annual period"); ensure placement of the biological sampling locations within thermally influenced areas; and inform the evaluation of potential impacts on recreation and water supply uses. However, it is important to emphasize that the >2ºC isopleth boundary is not a bright line; it is dynamic, changing geometrically in response to changes in ambient river flows and temperatures and SQN operations. As such, samples collected outside of, but generally proximate to the Primary Study Area boundary should not be discounted as non-thermally influenced. Every effort will be made to collect biological samples in thermally affected areas as guided by the Primary Study Area definition. Field activities will include measurement of surface to bottom temperature profiles along transects across the plume. One transect will be located proximate to the thermal discharge point; subsequent downstream transects will be concentrated in the near field area of the plume where the change in plume temperature is expected to be most rapid. The distance between transects in the remainder of the Primary Study Area will increase with distance downstream or away from the discharge point. The farthest downstream transect will be just outside of the Primary Study Area. A transect upstream of the discharge that is not affected by the thermal plume will be included for determining ambient temperature conditions. The total number of transects needed to fully characterize and delineate the plume will be determined in the field. Temperature profile measurement (surface to bottom) points along a given transect will begin at or near the shoreline from which the discharge originates and continue across the plume until ambient background temperature conditions (based on surface (0.1 meters (m)/0.3 ft depth) measurements) or the far shore is reached. The number of measurement points along transects will generally be proportional to the width of the plume and the magnitude of the temperature change across a given transect. The distances between transects and measurement points will depend on the size of the discharge plume. The temperature measurement instrument (Hydrolab or equivalent) will be calibrated to a thermometer whose calibration is traceable to the National Institute of Standards and Technology.

10 Temperature data will be compiled and analyzed to present the horizontal and vertical dimensions of the SQN thermal plume using spatial analysis techniques to yield plume cross-sections, which can be used to demonstrate the existence of a zone of passage under and/or around the plume. Task3-EstablishmentofBiologicalSamplingStationsWater temperature data from Task 2 will define the relationships between the biological sampling zone and thermally affected areas as informed by the EPA (1977) draft guidance, which identifies the Primary Study Area as having water temperatures of >2°C (3.6ºF) above ambient temperature. The thermally affected sampling location will be referred to as the "downstream zone;" the non-thermally-affected sampling location will be referred to as the "upstream zone." If it is determined, based on the plume temperature measurements/mapping that the currently used biological sampling zone downstream of SQN is not fully within the EPA guidance-defined Primary Study Area, that sampling zone will be re-established within the EPA Primary Study Area. Figure 3 depicts the downstream biological sampling zone; Figure 4 includes the location of the ambient biological sampling zone upstream of SQN. Task4-ShorelineandRiverBottomHabitatCharacterizationInformed by the results of Tasks 2 and 3, habitat characterization will be conducted at each selected sampling location to evaluate potential for bias in the results due to habitat differences between the thermally affected area and the ambient sampling locations, and to support interpretation of the biological data. Eight line-of-sight transects will be established across the width of Chickamauga Reservoir downstream and upstream of SQN to assess the quality of shoreline habitat (Figure 5). An integrative multi-metric index (Shoreline Aquatic Habitat Index or SAHI), including several habitat parameters important to resident fish species, will be used to measure the existing fish habitat quality. Using the SAHI, individual metrics are scored through comparison of observed conditions with reference conditions and assigned a corresponding value. River bottom habitat characterization for both the upstream and downstream study zones will consist of eight transects each collected perpendicular to the shoreline. Each transect will evaluate substrate by collecting 10 equally spaced Ponar dredge samples across the width of the reservoir. Each sample will be visually estimated to define substrate and then sieved to define percent makeup of substrate. At each sample location, depth, and sediment type encountered will be recorded. Sediment categories include bedrock, boulder, cobble, gravel, sand, fines, and detritus. Each site will be assigned one of three habitat categories to reduce the amount of assessment variability. Habitat categories are as follows: A) areas with presence of large substrates such as cobble and boulders, B) areas dominated by sand or fine substrates and C) areas with a presence of a mixture of both A and B (small and large) habitat types.

11 Task5-SupportingWaterQualityMeasurementsIn addition to the thermal plume measurements, additional water quality profiles will be collected as necessary in conjunction with the field studies to: (i) support interpretation of the biological data; and (ii) evaluate potential impacts to water supply and recreational uses. Using a Hydrolab, or equivalent unit, three water column profiles at one-meter increments will be collected near the left descending bank, right descending bank and mid-channel at the upstream and downstream ends of each sample zone, and other areas as needed (e.g., at water supply intakes). Each profile collected will include temperature, dissolved oxygen concentration, pH, and conductivity. Task6-BiologicalEvaluationsThe biological evaluations will focus on major representative species of the aquatic and wildlife community that could potentially be affected by the SQN thermal discharge. Sampling will be conducted during the summer months (mid-July - August) once during the SQN permit cycle to evaluate "worst case" conditions. Autumn monitoring (October - mid-December) will be conducted as a measure of potential manifested effects to the aquatic community from summer-long exposure to the thermal discharge and other stressors (basis for existing multi-metric assessments). The biological communities to be sampled and collection methodologies are provided in the following sections. ReservoirFishCommunityMonitoringInformed by the habitat characterization and temperature measurements, the fish community will be sampled during sample events at two locations: downstream within the thermal influence of the power plant (Figure 3); and upstream and beyond thermal influence of SQN (centered at TRM 489.5) (Figure 4). Sampling will be conducted by boat electrofishing and gill netting (Hubert 1996; Reynolds, 1996). The electrofishing methodology is based on existing monitoring programs and consists of 15 shoreline-oriented boat electrofishing runs in the upstream sampling zone and 15 shoreline runs in the downstream zone. Each run is 300 m (984 ft) long and electrofishing is conducted for a duration of approximately 15 minutes each. The total near-shore linear area sampled will be approximately 4,500 m (15,000 ft) per zone (Jennings, et al., 1995; Hickman and McDonough, 1996; McDonough and Hickman, 1999). Should the size of the SQN thermal plume (i.e., Primary Study Area) be too small to allow collection of all replicate electrofishing runs, the needed remaining replicate runs will be conducted as close as practicable to the Primary Study Area and be identified in the data analyses. As indicated previously, the >2ºC isopleth boundary that defines the Primary Study Area is not a rigid boundary; rather, its geometry changes in response to ambient river flows and temperatures and SQN operations (discharge flow). As such, samples collected outside of, but generally proximate to the Primary Study Area boundary should not be discounted as non-thermally influenced.

12 Experimental gill nets (so called because of their use for research as opposed to commercial fishing) are used as an additional gear type to collect fish from deeper habitats not effectively sampled by electrofishing. Each experimental gill net consists of five-6.1 m (20 ft) panels for a total length of 30.5 m (100 ft). The distinguishing characteristic of experimental gill nets is mesh size that varies between panels. For this application, each net has panels with mesh sizes of 2.5 (1 inch (in)), 5.1 (2 in), 7.6 (3 in), 10.2 (4 in), and 12.7 (5 in) centimeters (cm). Experimental gill nets are typically set perpendicular to river flow extending from near-shore to the main channel of the reservoir. Ten overnight experimental gill net sets will be used at each area. Fish collected will be identified by species, counted, and examined for anomalies (such as disease, deformities, or hybridization). ReservoirBenthicMacroinvertebrateCommunityMonitoringBenthic macroinvertebrates will be sampled with benthic grab samplers at ten equally-spaced points along the upstream (ambient) and downstream (mid-plume) sampling zones (Figures 3 and 4). A Ponar sampler (area per sample 0.06 m2) will be used for most samples. When heavier substrates are encountered, a Peterson sampler (area per sample 0.11 m2) will be used. Bottom sediments will be washed on a 533 micron () screen; organisms will be picked from the screen and from any remaining substrate. Organisms will be sent to an independent laboratory for identification to the lowest practicable taxonomic level. ReservoirPlanktonCommunityMonitoringAt the request of TDEC, phytoplankton samples will be obtained from a photic zone1 composite water sample collected at two locations each in the main channel area of the downstream sampling zone (Primary Study Area: mid-plume and plume downstream boundary; see Figure 3) and the upstream zone (Figure 4). This will be accomplished by lowering the intake end of a peristaltic pump sample tube to the bottom of the photic zone; and with the pump activated, slowly retrieving the sample tubing at a constant rate until the reservoir surface is reached. The phytoplankton data will be used to compare potential algal community response to thermal influence based on high-level taxonomy (i.e., Chrysophyta, Chlorophyta, Cyanophyta). Zooplankton samples will be collected with a plankton net (300 millimeter (1 ft) diameter with 153 mesh) towed at two locations each in the main channel area of the downstream sampling zone (Primary Study Area: mid-plume and plume downstream boundary) and the upstream zone (Figures 3 and 4). Tows will consist of a vertical pull (tow) of the entire water column from 2 m off the bottom to the surface of the reservoir. Comparative analysis of zooplankton data from the two locations will be used to evaluate potential thermal influence on community structure. 1 For the purposes of this study, the photic zone is defined as twice the Secchi disk transparency depth or 4 meters, whichever is greater.

13 Plankton sampling will be conducted once during the sampling events utilizing established TVA procedures. Among other criteria, these procedures specify replicate sampling, proper sample preservation, and data processing requirements. WildlifeCommunityEvaluationThe wildlife community will be evaluated via implementation of visual encounter (observational) wildlife survey methodology and supported through review of the available literature, and communications with natural resource agency contacts. The effort will focus on the more water dependent species of the herpetofaunal, avian, and mammalian communities.

These activities will assist in identifying the wildlife species expected for the ecoregion, establish the presence/absence of a BIP of wildlife in the study area, and support evaluation of potential direct effects of temperature on sensitive life stages and any indirect effects such as increased predation. A review of available resources to identify any threatened or endangered species potentially occurring in the study area will also be conducted.

For the visual encounter surveys, two permanent transects will be established both upstream and downstream of the SQN thermal effluent. The midpoint of the upstream transect will be positioned at TRM 489.5 and span a distance of 2,100 m within this transect. The downstream transect will be located in the field based on sampling event and likewise span a distance 2,100 m. The beginning and ending point of each transect will be marked with GPS for relocation. Transects will be positioned approximately 30 m offshore and parallel to the shoreline occurring on both right and left descending banks. Basic inventories will be conducted to provide a representative sampling of wildlife present during summer (mid-July - August) and late autumn-early winter (October - December). Each transect will be surveyed by steadily traversing the length by boat and simultaneously recording observations of wildlife. Sampling frame of each transect will generally follow the strip or belt transect concept with all individuals enumerated that crossed the center-line of each transect landward to an area that included the shoreline and riparian zone (i.e., belt width generally averages 60 m where vision is not obscured). Information recorded will include wildlife identification (to the lowest taxonomic trophic level) that is observed visually and/or audibly and a direct count of individuals observed per trophic level. If flocks of a species or mixed flock of a group of species are observed, an estimate of the number of individuals present will be generated. Time will be recorded at the starting and ending point of each transect to provide a general measure of effort expended. However, times may vary among transects primarily due to the difficulty in approaching some wildlife species without inadvertently flushing them from basking or perching sites. To compensate for the variation of effort expended per transect, observations will be standardized to numbers per minute or numbers per hectare in preparation for analysis.

14 The principal objective and purpose behind the wildlife surveys are to provide a preliminary set of observations to verify trophic levels of birds, mammals, amphibians and reptiles present that might be affected by thermal effects of the power plant (i.e., the ATL). If trophic levels are not represented, further investigation will be used to target specific species and/or species groups (guilds) that will determine the cause. Task7-WaterSupplyandRecreationalUseSupportEvaluationWater temperature data collected as part of the thermal mapping (Task 2) and collection of supporting water quality information (Task 5) will be used to evaluate potential thermal impacts to water supply and recreational uses in the vicinity of SQN. Locations of any public water supply intakes and/or established public recreational areas will be determined and their position(s) mapped relative to the SQN thermal plume. We are aware of one domestic water supply intake located within approximately 10 river miles downstream of the SQN thermal discharge (Figure 1). The existence of any relevant water temperature data collected by the owners of these water supply intake(s) will be determined; and if available, requested to augment the field-collected data. As necessary (limited or no available owner-supplied temperature data), direct measurements of water temperature may also be conducted specifically at these locations to evaluate potential thermal effects of the SQN discharge. 3.3DataContributiontotheAnalysis/DemonstrationThe analysis of fish, macroinvertebrate, and plankton community data will include traditional analyses whereby community attributes for the thermally affected areas will be compared to the non-thermally affected ambient location. For the purposes of the demonstration (within river/reservoir comparisons), the composition of fish and macroinvertebrate assemblages collected at the upstream station, uninfluenced by the SQN thermal discharge, is expected to set the baseline for evaluating the presence of a BIP in the downstream thermally influenced area. In that regard, a BIP is the expected determination for the thermally uninfluenced area. 3.3.1TraditionalAnalysesAs applicable, biological community data will be compiled into tables providing a listing of species collected and their status with regard to expected occurrence in the ecoregion. Reference materials such as: "The Fishes of Tennessee" (Etnier and Starnes, 1993); similarly applicable publications; and best professional judgment by experienced aquatic biologists will be used for this determination. The dataset will be further evaluated with regard to the following: Life stages represented, Food chain species present (e.g., predator and prey species), Thermally-tolerant or -sensitive species present (based on Yoder et al., 2006), Representative Important Species (commercially and/or recreationally); and Other community attributes (fish and macroinvertebrates) 15 To evaluate similarity with the downstream thermally influenced area, traditional species diversity indices will be used. Diversity indices provide important information about community composition and take the relative abundances of different species into account as well as species richness (i.e., number of individual species). Two diversity indices will be calculated for each sample location; such as: the Shannon-Weiner diversity index (H) (Levinton, 1982) and Simpson's Index of Diversity (Ds) (Simpson, 1949). Of the many biological diversity indices, these two indices are the most commonly reported in the scientific literature and will be evaluated for use in determining if community structure is similar between the thermally influenced and non-thermally influenced sampling locations. Other methods/indices for evaluating similarity between sampling sites will also be considered. Based on the BIP baseline for the thermally uninfluenced ambient (upstream) location, comparative statistical analysis of the diversity indices and/or other measures of biological community status such as: species richness, relative abundance, pollution tolerance, trophic guilds, indigenousness, and thermal sensitivity (each pending sufficient sample size) will be used to confirm the presence/absence of a BIP in the thermally influenced study area. 3.3.2SupportingMultimetricBioassessmentUpon review of the species listings and establishment that the fish and macroinvertebrate populations are appropriate to the aquatic systems of the ecoregion, sample data also will be analyzed using TVA's Reservoir Fish Assemblage Index (RFAI) methodology (McDonough and Hickman 1999) and Reservoir Benthic Index to further evaluate if the SQN thermal discharge has materially changed ecological conditions in the receiving water body (Tennessee River - Chickamauga Reservoir). Reservoir Fish Assemblage Index The RFAI uses 12 fish assemblage metrics from four general categories: Species Richness and Composition (8 metrics); Trophic Composition (two metrics); Abundance (one metric); and Fish Health (absence of anomalies) (one metric). Individual species can be utilized for more than one metric. Each metric is assigned a score based on "expected" fish assemblage characteristics in the absence of human-induced impacts other than impoundment of the reservoir. Individual metric scores for a sampling area (i.e., upstream or downstream) will be summed to obtain the RFAI score for each sample location and comparatively analyzed. The maximum RFAI score is 60. Ecological health ratings (12-21 "Very Poor", 22-31 "Poor", 32-40 "Fair", 41-50 "Good", or 51-60 "Excellent") are then applied to scores. Based on statistical analysis of multiple RFAI datasets, RFAI scores between sites (e.g., downstream vs. upstream) will need to differ by 6 points or more to be considered to have different fish assemblages based on documented variability in the sampling methodology.

16 Regardless of the scores, a metric-by-metric examination will be conducted; this review will be helpful in evaluating potential metric-specific impacts that may be thermally related. Reservoir Benthic Macroinvertebrate Index The RBI is similarly calculated as the RFAI except that it uses seven metrics specific to the macroinvertebrate assemblage. Each metric is assigned a score based on reference conditions and then summed to produce an overall RBI score for each sample site. The maximum RBI score is 35. Ecological health ratings (7-12 "Very Poor", 13-18 "Poor", 19-23 "Fair", 24-29 "Good", or 30-35 "Excellent") will then be applied to scores. Based on statistical analysis of multiple RBI datasets, RBI scores between sites (e.g., downstream vs. upstream) that differ by 4 points or more will be considered to have different macroinvertebrate assemblages. A metric-by-metric examination will also be conducted, regardless of the scores, to evaluate potential thermally-related impacts on specific metrics. 3.3.4ReasonablePotentialEvaluationBased on existing information and temperature data collected/obtained during the study, the reasonable potential for the thermal discharge to impair current and future water supply and recreational (water contact) uses will be evaluated. The measured temperatures at the water supply intake location and location of any named recreational areas or areas where recreational users are known to congregate within the thermally influenced area (if any), will form the basis for determining reasonable potential for use impairment. Should reasonable potential be indicated, TVA will discuss with TDEC; and as necessary, submit a revised scope of work (study design) for this task (Task 7) proposing additional data collections and/or analysis to focus the evaluation. 3.4ReportingA final Project Report will be prepared providing a description of the study design, data collection methods, SQN operational data, thermal plume mapping results, water quality monitoring data, and aquatic and wildlife community information. Raw data and associated field collection parameters will be appended to the report.

Results and conclusions regarding the §316(a) demonstration (maintenance of a BIP) and support of other use classifications (recreation and water supply) will be presented. 3.5StudyScheduleSummaryField sampling will be conducted during summer (mid-July - August) once during the SQN permit cycle and autumn (October - mid-December); each event will include sampling of the Primary Study Area/downstream zone and upstream/ambient zone.

17 TVA will provide TDEC with an interim progress report of the summer 2011 sampling results in spring of 2012. Final report will be completed and submitted with the SQN NPDES permit renewal package.

18 4.0LITERATURECITED EPA 1977. Draft Interagency 316(a) technical guidance manual and guide for thermal effects sections of nuclear facilities environmental impact statements. U.S. Environmental Protection Agency and U.S. Nuclear Regulatory Commission. U.S. Environmental Protection Agency, Office of Water Enforcement, Permits Division, Industrial Permits Branch, Washington, D.C. Etnier, D.A. & Starnes, W.C. 1993. The Fishes of Tennessee. University of Tennessee Press, Knoxville, TN, 681 pp. Hickman, G.D. and T.A. McDonough. 1996. Assessing the Reservoir Fish Assemblage Index- A potential measure of reservoir quality. In: D. DeVries (Ed.) Reservoir symposium- Multidimensional approaches to reservoir fisheries management. Reservoir Committee, Southern Division, American Fisheries Society, Bethesda, MD. pp 85-97. Hubert, W. A. 1996. Passive capture techniques, entanglement gears. Pages 160-165 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society, Bethesda, MD. Jennings, M. J., L. S. Fore, and J. R. Karr. 1995. Biological monitoring of fish assemblages in Tennessee Valley reservoirs, Regulated Rivers: Research and Management, Vol. 11, pages 263-274. Levinton, J.S. 1982. Marine Ecology. Prentice-Hall, Inc. Englewood Cliffs, NJ McDonough, T.A. and G.D. Hickman. 1999. Reservoir Fish Assemblage Index development: A tool for assessing ecological health in Tennessee Valley Authority impoundments. In: Assessing the sustainability and biological integrity of water resources using fish communities. Simon, T. (Ed.) CRC Press, Boca Raton, FL. pp 523-540. Reynolds, J.B. 1996. Electrofishing. Pages 221-251 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society, Bethesda, MD. Simpson, E.H. (1949) Measurement of diversity. Nature 163:688 see http://www.wku.edu/~smithch/biogeog/SIMP1949.htm TVA 2011. Biological Monitoring of the Tennessee River Near Sequoyah Nuclear Plant Discharge Autumn 2010. Tennessee Valley Authority, Knoxville, TN. TVA 1989. A Predictive 316(a) Demonstration for an Alternative Winter Thermal Discharge Limit for Sequoyah Nuclear Plant, Chickamauga Reservoir, Tennessee. Tennessee Valley Authority, Chattanooga, TN Yoder, C.O., B.J. Armitage, and E.T. Rankin. 2006. Re-evaluation of the technical justification for existing Ohio River mainstem temperature criteria. Midwest Biodiversity Institute, Columbus, OH.

19 FIGURES 20 Figure 1. Vicinity map for Sequoyah Nuclear plant depicting Chickamauga and Watts Bar Dam locations and water supply intakes downstream of the plant thermal discharge 21 Figure 2. Site map for Sequoyah Nuclear plant showing condenser cooling water intake structure, skimmer wall, and NPDES-permitted discharge Outfall No. 101 22 Figure 3. Biological monitoring zone downstream of Sequoyah Nuclear plant Biomonitoring Stations Downstream of Sequoyah Nuclear Plant

  • Electrofishing Stations o Gill Netting Stations -Benthic Macroinvertebrate Transects 23 Figure 4. Biological monitoring zone upstream of Sequoyah Nuclear plant thermal discharge Biomonitoring Stations Upstream of Sequoyah Nuclear Plant
  • Electrofishing Stations o Gill Netting Stations -Benthic Macroinvertebrate Transects .
  • 24 Figure 5. Anticipated transects to be established for conduct of the integrative multi-metric aquatic shoreline habitat assessment Transects for Shoreline Aquatic Habitat Index (SAHI) Upstream and Downstream of Sequoyah Nuclear Plant CCW Discharge --SAHI Transects Biological Monitoring of the Tennessee River Near Sequoyah Nuclear Plant Discharge, Summer and Autumn 2011 May 2012 Tennessee Valley Authority Biological and Water Resources Knoxville, Tennessee Table of Contents Table of Contents ............................................................................................................................. iList of Tables ................................................................................................................................. iiiList of Figures ................................................................................................................................ viAcronyms and Abbreviations ...................................................................................................... viiiIntroduction ..................................................................................................................................... 1Plant Description ............................................................................................................................. 2Methods........................................................................................................................................... 2Shoreline Aquatic Habitat Assessment ........................................................................................... 2River Bottom Habitat ...................................................................................................................... 3Fish Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN....................................................................................................................................... 3Traditional Analyses ....................................................................................................................... 8Benthic Macroinvertebrate Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN ...................................................................................................... 9Plankton Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN ................................................................................................................................ 11Phytoplankton ............................................................................................................................... 11Zooplankton .................................................................................................................................. 12Data Analysis ................................................................................................................................ 12Visual Encounter Surveys (Observations of Wildlife) ................................................................. 12Chickamauga Reservoir Flow and SQN Temperature .................................................................... 1Thermal Plume Characterization .................................................................................................... 1Water Quality Parameters at Fish Sampling Sites during RFAI Samples ...................................... 2Results and Discussion ................................................................................................................... 2Aquatic Habitat in the Vicinity of SQN .......................................................................................... 2Shoreline Aquatic Habitat Assessment ........................................................................................... 2River Bottom Habitat ...................................................................................................................... 3Fish Community.............................................................................................................................. 3Traditional Analyses ....................................................................................................................... 9Benthic Macroinvertebrate Community ....................................................................................... 12Plankton Community .................................................................................................................... 15Plankton Summary ........................................................................................................................ 18Review of Previous Plankton Studies ........................................................................................... 19Visual Encounter Survey/Wildlife Observations .......................................................................... 20Chickamauga Reservoir Flow and Temperature Near SQN ......................................................... 21i Thermal Plume Characterization .................................................................................................. 21Water Quality Parameters at Fish Sampling Sites During RFAI Samples ................................... 22Literature Cited ............................................................................................................................. 23Tables ............................................................................................................................................ 25Figures........................................................................................................................................... 77 ii List of Tables Table 1. Shoreline Aquatic Habitat Index (SAHI) metrics and scoring criteria. ......................... 26Table 2. Expected values for upper mainstem Tennessee River reservoir transition and forebay zones ................................................................................................................................... 27Table 3. Average trophic guild proportions and average number of fish species, bound by confidence intervals (95%), expected in upper mainstem Tennessee River reservoir transition and forebay zones and proportions and numbers of species observed during summer and autumn 2011. .................................................................................................. 28Table 4. RFAI scoring criteria (2002) for fish community samples in forebay, transition, and inflow sections of upper mainstream Tennessee River reservoirs. ..................................... 29Table 5. Scoring criteria for benthic macroinvertebrate community samples (lab-processed) for forebay, transition, and inflow sections of mainstream Tennessee River reservoirs. ......... 30Table 6. SAHI scores for 16 shoreline habitat assessments conducted within the Upstream RFAI sampling area of SQN on Chickamauga Reservoir, autumn 2009. .................................... 31Table 7. SAHI Scores for 16 Shoreline Habitat Assessments Conducted within the Downstream RFAI Sampling Area of SQN on Chickamauga Reservoir, Autumn 2009. ....................... 32Table 8. Substrate percentages and average water depth (ft) per transect upstream (8 transects) and downstream (8 transects) of SQN. ............................................................................... 33Table 9. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 482) and Upstream (TRM 490.5) of Sequoyah Nuclear Plant Summer 2011. .................................. 34Table 10. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 482) and Upstream (TRM 490.5) of (Sequoyah nuclear) Autumn 2011. .......................................... 38Table 11. Summer 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Downstream (TRM 482.0) of Sequoyah Nuclear Plant Discharge, Summer 2011. ........... 42Table 12. Summer 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 490.5) of Sequoyah Nuclear Plant Discharge, Summer 2011. ................................ 43Table 13. Autumn 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Downstream (TRM 482.0) of Sequoyah Nuclear Plant Discharge, Autumn 2011. ........... 44Table 14. Autumn 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 490.5) of Sequoyah Nuclear Plant Discharge, Autumn 2011. ................................. 45Table 15. Spatial statistical comparisons of numbers of species, mean electrofishing catch per unit effort values (number/run), tolerance designations, trophic levels, and non-indigenous individuals, along with species richness and Simpson and Shannon diversity values, collected near Sequoyah Nuclear Plant, summer 2011. ...................................................... 46Table 16. Spatial statistical comparisons of numbers of species, mean electrofishing catch per unit effort values (number/run), tolerance designations, trophic levels, and non-indigenous individuals, along with species richness and Simpson and Shannon diversity values, collected near Sequoyah Nuclear Plant, autumn 2011. ....................................................... 47iii Table 17. Summary of RFAI scores from sites located directly upstream and downstream of Sequoyah Nuclear Plant as well as scores from sampling conducted during autumn 1993-2011 as part of the Vital Signs Monitoring Program in Chickamauga Reservoir. ............. 48Table 18. Comparison of mean density per square meter of benthic taxa collected at upstream and downstream sites near SQN during August and October 2011. ................................... 49Table 19. Summary of RBI Scores from Sites Located Directly Upstream and Downstream of Sequoyah Nuclear Plant as Well as Scores from Sampling Conducted as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir. ..................................................... 50Table 20. Comparison of mean density per Square Meter of Benthic Taxa collected with a Ponar Dredge along Transects Upstream and Downstream of Sequoyah Nuclear Plant, Chickamauga Reservoir, Summer and Autumn 2011. ........................................................ 51Table 21. Individual Metric Ratings and the Overall RBI Field Scores for Downstream and Upstream Sampling Sites Near SQN, Chickamauga Reservoir, Autumn 2000-2010. ....... 56Table 22. Mean percent composition of major phytoplankton groups at sites sampled upstream and downstream of SQN in August and October, 2011. ..................................................... 57Table 23. Comparison of the similarity of phytoplankton taxa within paired replicate samples. 57Table 24. Taxa richness of the main phytoplankton groups. ....................................................... 57Table 25. Percent Similarity Index for comparison of phytoplankton communities among sites.............................................................................................................................................. 57Table 26. Phytoplankton taxa and density (cells/ml) data for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. Abbreviations "R1" and R2" designate replicate samples. ................................................. 58Table 27. Percentage Composition of phytoplankton for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. ...... 61Table 28. Concentrations of chlorophyll a (apparent and corrected), phaeophytin a and the chlorophyll/phaeophytin index values for samples collected upstream and downstream of SQN during 2011. ............................................................................................................... 64Table 29. Mean percent composition of major zooplankton groups at sites sampled upstream and downstream of SQN in August and October, 2011. ........................................................... 64Table 30. Comparison of the similarity of zooplankton taxa within paired replicate samples. ... 65Table 31. Taxa richness of the main zooplankton groups. ........................................................... 65Table 32. Percent Similarity Index for comparison of zooplankton communities among sites. . 65Table 33. Zooplankton taxa and density (organisms/m3) data for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. Abbreviations "R1" and R2" designate replicate samples. ................................ 66Table 34. Percentage composition of zooplankton taxa for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011.............................................................................................................................................. 68Table 35. Wildlife Visual Encounter Survey Results of Shoreline Upstream and Downstream of Sequoyah Nuclear Plant during August (Summer) and October (Autumn) 2011. (RDB = right descending bank, LDB = Left Descending Bank) ...................................................... 70iv Table 36. Water temperature (°F) profiles measured at five locations (10%, 30%, 50%, 70%, 90%) from right descending bank along transects located at TRM 486.7 (ambient), TRM 483.4 (discharge), TRM 481.1 (middle of plume), TRM 480.0 (downstream limit of plume), and TRM 478.3 (below plume) on August 25, 2011 (Summer). ........................... 71Table 37. Water temperature (°F) profiles measured at five locations (10%, 30%, 50%, 70%, 90%) from right descending bank along transects located at TRM 487 (ambient), TRM 483.4 (discharge), TRM 482.2 (below discharge), TRM 481.0 (downstream limit of plume), and TRM 478.3 (below plume) on September 14, 2011 (Autumn). ..................... 72Table 38. Seasonal water quality parameters collected along vertical depth profiles downstream (TRM 482) and upstream (TRM 490.5) of the Sequoyah Nuclear Plant in Chickamauga Reservoir on the Tennessee River. Abbreviations: °C -Temperature in degrees Celsius, °F - Temperature in degrees Fahrenheit, Cond - Conductivity, DO - Dissolved Oxygen ..... 73 v List of Figures Figure 1. Vicinity map for Sequoyah Nuclear plant depicting Chickamauga and Watts Bar Dam locations and water supply intakes downstream of the plant thermal discharge ................ 78Figure 2. Site map for Sequoyah Nuclear plant showing condenser cooling water intake structure, skimmer wall, and NPDES-permitted discharge Outfall No. 101 ...................... 79Figure 3. Biological monitoring stations upstream of Sequoyah Nuclear Plant. ......................... 80Figure 4. Biological monitoring stations downstream of Sequoyah Nuclear Plant, including mixing zone and thermal plume from SQN CCW discharge. ............................................ 81Figure 5. Benthic and shoreline habitat transects within the fish community sampling area upstream and downstream of SQN. .................................................................................... 82Figure 6. Locations of water temperature monitoring stations used to compare water temperatures upstream of SQN intake and downstream of SQN discharge during October 2010 through November 2011. ........................................................................................... 83Figure 7. Substrate composition at ten equally spaced points per transect (1 and 2) across the Tennessee River downstream of SQN. ............................................................................... 84Figure 8. Substrate composition at ten equally spaced points per transect (3 and 4) across the Tennessee River downstream of SQN. ............................................................................... 85Figure 9. Substrate composition at ten equally spaced points per transect (5 and 6) across the Tennessee River downstream of SQN. ............................................................................... 86Figure 10. Substrate composition at ten equally spaced points per transect (7 and 8) across the Tennessee River downstream of SQN. ............................................................................... 87Figure 11. Substrate composition at ten equally spaced points per transect (1 and 2) across the Tennessee River upstream of SQN. .................................................................................... 88Figure 12. Substrate composition at ten equally spaced points per transect (3 and 4) across the Tennessee River upstream of SQN. .................................................................................... 89Figure 13. Substrate composition at ten equally spaced points per transect (5 and 6) across the Tennessee River upstream of SQN. .................................................................................... 90Figure 14. Substrate composition at ten equally spaced points per transect (7 and 8) across the Tennessee River upstream of SQN. .................................................................................... 91Figure 15. Number of indigenous fish species collected during RFAI samples downstream of SQN (TRM 482) during 1996 and 1999 through 2011....................................................... 92Figure 16. Number of indigenous fish species collected during RFAI samples upstream of SQN (TRM 490.5) during 1993 to 1997 and 1999 through 2011. .............................................. 92Figure 17. Proportions of selected benthic taxa from Ponar dredge sampling at locations upstream and downstream of SQN, summer and autumn 2011. ......................................... 93Figure 18. Mean phytoplankton densities (cells/ml) for samples collected August 25, 2011. .... 94Figure 19. Mean phytoplankton biovolume (µm3/ml) for samples collected August 25, 2011. . 94Figure 20. Mean phytoplankton densities (cells/ml) for samples collected October 10, 2011. .... 94Figure 21. Mean phytoplankton biovolume (µm3/ml) for samples collected October 10, 2011. 94Figure 22. Mean chlorophyll a concentrations for samples collected August 25 and October 10, 2011..................................................................................................................................... 95vi Figure 23. Mean zooplankton densities (number/m3) for samples collected August 25, 2011. .. 95Figure 24. Mean zooplankton densities (number/m3) for samples collected October 10, 2011 .. 95Figure 25. Dendrogram of phytoplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected August 25, 2011. Samples for each location are coded by river mile and month. (Coph. Corr = 0.89) .................................................................................................................................... 96Figure 26. Dendrogram of phytoplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected October 10, 2011. Samples for each location are coded by river mile and month. (Coph. Corr =

0.78) .................................................................................................................................... 97Figure 27. Dendrogram of zooplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected August 25, 2011. Samples for each location are coded by river mile and month. (Coph. Corr =

0.87) .................................................................................................................................... 98Figure 28. Dendrogram of zooplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected October 10, 2011. Samples for each location are coded by river mile and month. (Coph. Corr =

0.78) .................................................................................................................................... 99Figure 29. Average hourly discharge from Chickamauga, Watts Bar, Apalachia, and Ocoee #1 dams, August 23 through August 25, 2011 ...................................................................... 100Figure 30. Average hourly discharge from Chickamauga, Watts Bar, Apalachia, and Ocoee #1 dams, October 8 through October 10, 2011 ...................................................................... 100Figure 31. Total daily average releases (cubic feet per second) from Watts Bar, Apalachia, and Ocoee 1 dams, October 2010 through November 2011 and historic daily average flows averaged for the same period 1976 through 2010. ............................................................ 101Figure 32. Daily average water temperatures (°F) at a depth of five feet, recorded upstream of SQN intake (Station 14) and downstream of SQN discharge (Station 8), October 2009 through November 2010. .................................................................................................. 102 vii viii Acronyms and Abbreviations BIP Balanced Indigenous Population CCW Condenser cooling water CFS Cubic feet per second MW Megawatts NPDES National Pollutant Discharge Elimination System QA Quality Assurance RBI Reservoir Benthic Macroinvertebrate Index RFAI Reservoir Fish Assemblage Index SAHI Shoreline Assessment Habitat Index SQN Sequoyah Nuclear Plant TRM Tennessee River Mile TVA Tennessee Valley Authority VS Vital Signs

Introduction Section 316(a) of the Clean Water Act (CWA) authorizes alternative thermal limits (ATL) for the control of the thermal component of a discharge from a point source so long as the limits will assure the protection of Balanced Indigenous Populations (BIP) of aquatic life. The term "balanced indigenous population," as defined in EPA's regulations implementing Section 316(a), means a biotic community that is typically characterized by: (1) diversity appropriate to ecoregion; (2) the capacity to sustain itself through cyclic seasonal changes; (3) the presence of necessary food chain species; (4) lack of domination by pollution-tolerant species; and Prior to 1999, the Tennessee Valley Authority's (TVA) Sequoyah Nuclear Plant (SQN) was operating under a 316(a) ATL that had been continued with each permit renewal based on studies conducted in the mid-1970s. In 1999, EPA Region IV began requesting additional data in conjunction with NPDES permit renewal applications to verify that BIP was being maintained at TVA's thermal plants with ATLs. TVA proposed that its existing Vital Signs (VS) monitoring program, supplemented with additional fish and benthic macroinvertebrate community monitoring upstream and downstream of thermal plants with ATLs, was appropriate for that purpose. The VS monitoring program began in 1990 in the Tennessee River System. This program was implemented to evaluate ecological health conditions in major reservoirs as part of TVA's stewardship role. One of the 5 indicators used in the VS program to evaluate reservoir health is the Reservoir Fish Assemblage Index (RFAI) methodology. RFAI has been thoroughly tested on TVA and other reservoirs and published in peer-reviewed literature (Jennings, et al., 1995; Hickman and McDonough, 1996; McDonough and Hickman, 1999). Fish communities are used to evaluate ecological conditions because of their importance in the aquatic food web and because fish life cycles are long enough to integrate conditions over time. Benthic macroinvertebrate populations are assessed using the Reservoir Benthic Index (RBI) methodology. Because benthic macroinvertebrates are relatively immobile, negative impacts to aquatic ecosystems can be detected earlier in benthic macroinvertebrate communities than in fish communities. These data are used to supplement RFAI results to provide a more thorough examination of differences in aquatic communities upstream and downstream of thermal discharges. TVA initiated a study to evaluate fish and benthic macroinvertebrate communities in areas immediately upstream and downstream of SQN during autumn 1999-2011 using RFAI and RBI multi-metric evaluation techniques. Beginning in 2011, evaluations of plankton and wildlife communities were included as well. This report presents the results of summer and autumn 2011 RFAI, RBI, plankton, and wildlife data collected upstream and downstream of SQN. 1 Plant Description Sequoyah Nuclear Power Plant (SQN) is located on the right (west) bank of Chickamauga Reservoir at Tennessee River Mile (TRM) 484.5 approximately 18 miles northeast of Chattanooga, Tennessee, and 7 miles southwest of Soddy-Daisy, Tennessee. SQN is situated approximately 54.5 river miles downstream from Watts Bar Dam and 13.5 river miles upstream from Chickamauga Dam (Figure 1). SQN Unit 1 began commercial operation on July 1, 1981, and Unit 2 on June 1, 1982. Net operating capacity is about 2,400 MW of electricity. Waste heat load is about 4,800 MW of thermal energy. Waste heat is transferred to the condenser cooling water (CCW), pumped from the river at TRM 484.8 (Figure 2). This heat is then dissipated either to the atmosphere using two natural-draft cooling towers, to the river through a two-leg submerged multiport diffuser located at TRM 483.6, or by a combination of the two. With both units operating at maximum power, maximum CCW water demand is 2,558 cfs. Methods Aquatic Habitat in the Vicinity of SQN Shoreline and river bottom habitat data presented in this report were collected during autumn 2009. TVA assumes habitat data to be valid for three years, barring any major changes to the river/reservoir (e.g., flood). Since no significant changes have occurred in the river system from the initial characterization, habitat will be sampled again during the next autumn sampling event. In the event of a major change to the river/reservoir, habitat would be re-sampled the following autumn.

Shoreline Aquatic Habitat Assessment An integrative multi-metric index (Shoreline Aquatic Habitat Index or SAHI), including several habitat parameters important to resident fish species, was used to measure existing fish habitat quality in the vicinity of Sequoyah Nuclear Plant. Using the general format developed by Plafkin et al. (1989), seven metrics were established to characterize selected physical habitat attributes important to resident fish populations which rely heavily on the littoral or shoreline zone for reproductive success, juvenile development, and/or adult feeding (Table 1). Habitat Suitability Indices (US Fish and Wildlife Service), along with other sources of information on biology and habitat requirements (Etnier and Starnes 1993), were consulted to develop "reference" criteria or "expected" conditions from a high quality environment for each parameter. Some generalizations were necessary in setting up scoring criteria to cover the various requirements of all species into one index. Individual metrics are scored through comparison of observed conditions with these "reference" conditions and assigned a corresponding value: good-5; fair-3; or poor-1 (Table 1). The scores for each metric are summed to obtain the SAHI value. The range of potential SAHI values (7-35) is trisected to provide some descriptor of habitat quality (poor: 7-16; fair: 17-26; and good: 27-35). 2 The quality of shoreline aquatic habitat was assessed while traveling parallel to the shoreline in a boat and evaluating the habitat within 10 vertical feet of full pool. This was much easier to accomplish when the reservoir was at least 10 feet below full pool during the assessment allowing accurate determination of near-shore aquatic habitat quality. To sample river bottom habitat, eight line-of-sight transects were established across the width of Chickamauga reservoir within the SQN downstream (TRMs 481.1 to 483.6) and upstream (TRMs 487.9 to 491.1) fish community sampling areas (Figure 5). Near-shore aquatic habitat was assessed along sections of shoreline corresponding to the left descending (LDB) and right descending (RDB) bank locations for each of the eight line-of-sight transects. These individual sections (8 on the LDB and 8 on the RDB for a total of 16 shoreline assessments) were scored using SAHI criteria. Percentages of aquatic macrophytes in the littoral areas of the 8 LDB and 8 RDB shoreline sections were also estimated. River Bottom Habitat Along each of the 8 line-of-sight transects described above, 10 benthic grab samples were collected with a Ponar sampler at equally spaced points from the LDB to RDB. Substrate material collected with the Ponar was dumped into a screen and substrate percentages were estimated to determine existing benthic habitat across the width of the river. Water depths at each sample location were recorded (feet). If no substrate was collected after multiple Ponar drops, it was assumed that the substrate was bedrock. For example, when the Ponar was pulled shut, collectors could feel substrate consistency; if it shut easily and was not embedded in the substrate on numerous drops within the same location, substrate was recorded as bedrock. Fish Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN Two sample locations, one upstream and one downstream of the plant discharge were selected in Chickamauga Reservoir. The SQN discharge enters the Tennessee River at TRM 483.6 (Figure 2). The upstream monitoring site was centered at TRM 490.5 (Figure 3) and the downstream site was centered at TRM 482.0 (Figure 4). Fish sampling methods included boat electrofishing and gill netting (Hubert, 1996; Reynolds, 1996). Electrofishing methodology consisted of fifteen boat electrofishing runs near the shoreline, each 300 meters long with a duration of approximately 10 minutes each. The total near-shore area sampled was approximately 4,500 meters (15,000 feet). Experimental gill nets (so called because of their use for research as opposed to commercial fishing) were used as an additional gear type to collect fish from deeper habitats not effectively sampled by electrofishing. Each experimental gill net consists of five 6.1-meter panels for a total length of 30.5 meters (100.1 feet). The distinguishing characteristic of experimental gill nets is mesh size that varies between panels. For this application, each net has panels with mesh sizes of 2.5, 5.1, 7.6, 10.2, and 12.7 cm. Experimental gill nets are typically set perpendicular to river flow extending from near-shore toward the main channel of the reservoir. Ten overnight experimental gill net sets were used at each area. 3 Fish collected were identified by species, counted, and examined for anomalies (such as disease, deformations, parasites, or hybridization). The resulting data were analyzed using RFAI methodology. The RFAI uses 12 fish community metrics from four general categories: Species Richness and Composition; Trophic Composition; Abundance; and Fish Health. Individual species can be utilized for more than one metric. Together, these 12 metrics provide a balanced evaluation of fish community integrity. The individual metrics are described below, grouped by category: Species Richness and Composition (1) Total number of indigenous species -- Greater numbers of indigenous species are considered representative of healthier aquatic ecosystems. As conditions degrade, numbers of species at an area decline. (2) Number of centrarchid species -- Sunfish species (excluding black basses) are invertivores and a high diversity of this group is indicative of reduced siltation and suitable sediment quality in littoral areas.

(3) Number of benthic invertivore species -- Due to the special dietary requirements of this species group and the limitations of their food source in degraded environments, numbers of benthic invertivore species increase with better environmental quality.

(4) Number of intolerant species -- This group is made up of species that are particularly intolerant of physical, chemical, and thermal habitat degradation. Higher numbers of intolerant species suggest the presence of fewer environmental stressors. (5) Percentage of tolerant individuals (excluding Young-of-Year) -- This metric signifies poorer water quality with increasing proportions of individuals tolerant of degraded conditions.

(6) Percent dominance by one species -- Ecological quality is considered reduced if one species inordinately dominates the resident fish community. (7) Percentage of non-indigenous species -- Based on the assumption that non-indigenous species reduce the quality of resident fish communities. 4 (8) Number of top carnivore species -- Higher diversity of piscivores is indicative of the availability of diverse and plentiful forage species and the presence of suitable habitat. Trophic Composition (9) Percentage of individuals as top carnivores -- A measure of the functional aspect of top carnivores which feed on major planktivore populations. (10) Percentage of individuals as omnivores -- Omnivores are less sensitive to environmental stresses due to their ability to vary their diets. As trophic links are disrupted due to degraded conditions, specialist species such as insectivores decline while opportunistic omnivorous species increase in relative abundance.

Abundance (11) Average number per run -- (number of individuals) -- This metric is based upon the assumption that high quality fish assemblages support large numbers of individuals. Fish Health (12) Percentage of individuals with anomalies -- Incidence of diseases, lesions, tumors, external parasites, deformities, blindness, and natural hybridization are noted for all fish measured, with higher incidence indicating less favorable environmental conditions. RFAI methodology addresses all four attributes or characteristics of a "balanced indigenous population" defined by the CWA, as described below:

(1.) A biotic community characterized by diversity appropriate to the ecoregion: Diversity is addressed by the metrics in the Species Richness and Composition category, especially metric 1 - "total number of indigenous species." Determination of reference conditions based on the forebay and transition zones of upper mainstem Tennessee River reservoirs (as described below) ensures appropriate species expectations for the ecoregion. (2.) The capacity for the community to sustain itself through cyclic seasonal change: TVA uses an autumn data collection period for biological indicators, both VS and upstream/downstream monitoring. Autumn monitoring is used to document community condition or health after being subjected to the wide variety of stressors throughout the year. One of the main benefits of using biological indicators is their ability to integrate stressors through time. Examining the condition or health of a community at the end of the "biological year" (i.e., autumn) provides insight into how well the community has dealt with the stresses through an annual seasonal cycle. Likewise, evaluation of the condition of individuals in the community (in this case, individual fish as reflected in Metric 12) provides insight into how well the community can be expected to withstand stressors through winter. Further, multiple sampling years during the permit renewal cycle add to the evidence of whether or not the autumn 5 monitoring approach has correctly demonstrated the ability of the community to sustain itself through repeated seasonal changes. Summer sampling was conducted during August 2011. This time of year is considered a stressful time for the biotic community. Summer sampling was conducted to collect data on the biotic community during a high stress period near SQN plant. These data were compared with data collected during summer 2010.

(3.) The presence of necessary food chain species: Integrity of the food chain is measured by the Trophic Composition metrics, with support from the Abundance metric and Species Richness and Composition metrics. Existence of a healthy fish community indicates presence of necessary food chain species because the fish community is comprised of species that utilize multiple feeding mechanisms that transcend various levels in the aquatic food web. Basing evaluations on a sound multi-metric system such as the RFAI enhances the ability to discern alterations in the aquatic food chain.

Three dominant fish trophic levels exist within Tennessee River reservoirs; insectivores, omnivores, and top carnivores. To determine the presence of necessary food chain species, these three groups should be well represented within the overall fish community. Other fish trophic levels include benthic invertivores, planktivores, herbivores, and parasitic species. Insectivores include most sunfish, minnows, and silversides. Omnivores include gizzard shad, common carp, carpsuckers, buffalo, channel catfish, and blue catfish. Top carnivores include black bass, gar, skipjack herring, crappie, flathead catfish, sauger, and walleye. Benthic invertivores include freshwater drum, suckers, and darters. Planktivores include alewife, threadfin shad, and paddlefish. Herbivores include largescale stonerollers. Lampreys in the genus Ichthyomyzon are the only parasitic species occurring in Tennessee River reservoirs.

To establish expected proportions of each trophic guild and the expected number of species included in each guild occurring in upper mainstem Tennessee River reservoirs (Nickajack, Chickamauga, Watts Bar, and Fort Loudon reservoirs), data collected from 1993 to 2010 during autumn were analyzed for each reservoir zone where upstream and downstream sample stations were established to monitor effects of the SQN discharge (forebay- downstream of SQN and transition- upstream of SQN). Samples collected in the downstream vicinity of thermal discharges were not included in this analysis so that accurate expectations could be calculated with the assumption that these data represent what should occur in upper mainstem Tennessee River reservoirs absent from point source effects (i.e. power plant discharges). Therefore, data from the monitoring site downstream of SQN at TRM 482 were not included in this analysis. Data from 900 electrofishing runs (a total of 270,000 meters of shoreline sampled) and from 600 overnight experimental gill net sets were included in this analysis for forebay areas in upper mainstem Tennessee River reservoirs. For upper mainstem Tennessee River transition zones, data from 750 electrofishing runs and 500 overnight experimental gill net sets were included. From these data, the range of proportional values for each trophic level and the range of the number of species included in each trophic level were trisected. This trisection is intended to show less than expected, expected and above expected values for trophic level proportions and species occurring within each reservoir zone in upper mainstem Tennessee River reservoirs (Table 2). These data were also averaged and bound by confidence intervals (95%) to further 6 evaluate expected values for proportions of each trophic level and the number of species expected for each trophic level by reservoir zone (Table 3).

(4.) A lack of domination by pollution-tolerant species: Domination by pollution-tolerant species is measured by metrics 3 ("Number of benthic invertivore species"), 4 ("Number of intolerant species"), 5 ("Percentage of tolerant individuals"), 6 ("Percent dominance by one species"), and 10 ("Percentage of individuals as omnivores"). Scoring categories are based on "expected" fish community characteristics in the absence of human-induced impacts other than impoundment of the reservoir. These categories were developed from historical fish assemblage data representative of forebay and transition zones from upper mainstem Tennessee River reservoirs (Hickman and McDonough, 1996). Attained values for each of the 12 metrics were compared to the scoring criteria and assigned scores to represent relative degrees of degradation: least degraded (5); intermediate degraded (3); and most degraded (1). Scoring criteria for upper mainstem Tennessee River reservoirs are shown in Table 4. If a metric was calculated as a percentage (e.g., "Percentage of tolerant individuals"), data from electrofishing and gill netting were scored separately and allotted half the total score for that individual metric. Individual metric scores for a sampling area (e.g., upstream or downstream) are summed to obtain the RFAI score for the area.

TVA uses RFAI results to determine maintenance of BIP using two approaches. One is "absolute" in that it compares the RFAI scores and individual metrics to predetermined values. The other is "relative" in that it compares RFAI scores attained downstream to the upstream control site. The "absolute" approach is based on Jennings et al. (1995) who suggested that favorable comparisons of the attained RFAI score from the potential impact zone to a predetermined criterion can be used to identify the presence of normal community structure and function and hence existence of BIP. For multi-metric indices, TVA uses two criteria to ensure a conservative screening of BIP. First, if an RFAI score reaches 70% of the highest attainable score of 60 (adjusted upward to include sample variability as described below), and second, if fewer than half of RFAI metrics receive a low (1) or moderate (3) score, then normal community structure and function would be present indicating that BIP had been maintained, thus no further evaluation would be needed. RFAI scores range from 12 to 60. Ecological health ratings (12-21 ["Very Poor"], 22-31 ["Poor"], 32-40 ["Fair"], 41-50 ["Good"], or 51-60 ["Excellent"]) are then applied to scores. As discussed in detail below, the average variation for RFAI scores in TVA reservoirs is 6 (+ 3). Therefore, any location that attains an RFAI score of 45 or higher would be considered to have BIP. It must be stressed that scores below this threshold do not necessarily reflect an adversely impacted fish community. The threshold is used to serve as a conservative screening level; i.e., any fish community that meets these criteria is obviously not adversely impacted. RFAI scores below this level would require a more in-depth look to determine if BIP exists. An inspection of individual RFAI metric results and species of fish used in each metric would be an initial step to help identify if operation of SQN is a contributing factor. This approach is appropriate because a validated multi-metric index is being used and scoring criteria applicable to the zone of study are available. 7 A difference in RFAI scores attained at the downstream area compared to the upstream (control) area is used as one basis for determining presence or absence of impacts on the resident fish community from SQN's operations. The definition of "similar" is integral to accepting the validity of these interpretations. The Quality Assurance (QA) component of the Vital Signs monitoring program deals with how well the RFAI scores can be repeated and is accomplished by collecting a second set of samples at 15%-20% of the areas each year. Comparison of paired-sample QA data collected over seven years shows that the difference in RFAI index scores ranges from 0 to 18 points. The mean difference between these 54 paired scores is 4.6 points with 95% confidence limits of 3.4 and 5.8. The 75th percentile of the sample differences is 6, and the 90th percentile is 12. Based on these results, a difference of 6 points or less in the overall RFAI scores is the value selected for defining "similar" scores between upstream and downstream fish communities. That is, if the downstream RFAI score is within 6 points of the upstream score and if there are no major differences in overall fish community composition, then the two locations are considered similar. It is important to bear in mind that differences greater than 6 points can be expected simply due to method variation (i.e., 25% of the QA paired sample sets exceeded a difference of 6). An examination of the 12 metrics (with emphases on fish species used for each metric) is conducted to determine any difference in scores and the potential for the difference to be thermally related. Traditional Analyses In addition to RFAI analyses, data were analyzed using traditional statistical methods. Data from the survey were used to calculate catch per unit effort (CPUE), which was expressed as number of fish per electrofishing run or fish per net night. CPUE values were calculated by pollution tolerance, trophic guilds (e.g., benthic invertivores, top carnivores, etc.), thermal sensitivity (Yoder et al. 2006), and indigenousness. CPUE, species richness, and diversity values were computed for each electrofishing effort (to maximize sample size; n = 30) and compared upstream and downstream to assess potential effects of power plant discharges. Diversity was quantified using two commonly used diversity indices: Shannon diversity index (Shannon 1948) and Simpson diversity index (Simpson 1949). Both indices account for the number of species present, as well as the relative abundance of each species. Shannon diversity index values were computed using the formula: where: S = total number of species N = total number of individuals ni = total number of individuals in the ith species The Simpson diversity index was calculated as follows: 8 where: S = total number of species N = total number of individuals ni = total number of individuals in the ith species An independent two-sample t-test was used to test for differences in CPUE, species richness, and diversity values upstream and downstream of SQN ( = 0.05). Before statistical tests were performed using this method, data were analyzed for normality using the Shapiro-Wilk test (Shapiro and Wilk, 1965) and homogeneity of variance using Levene's test (Levene, 1960). Non-normal count data or data with unequal variances were transformed using square root conversion; the transformation ln(x+1) was used for CPUE data without a normal distribution or unequal variance. Transformed data was reanalyzed for normal distribution and equal variances. If transformation normalized the data and/ or resulted in homogeneous variances, transformed data were tested using an independent two-sample t-test. If transformed data were not normally distributed or had unequal variances, statistical analysis was conducted using the Wilcoxon-Mann-Whitney test (Mann and Whitney, 1947; Wilcoxon, 1945).

Benthic Macroinvertebrate Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN During summer 2011, benthic macroinvertebrate data were collected along transects established across the full width of the reservoir at TRMs 481.3 and 483.4 downstream of SQN (Figure 3) and TRMs 488.0 and 490.5 upstream of SQN (Figure 4). Autumn 2011 sites included only TRM 481.3, TRM 483.4 and TRM 490.5. TRM 488.0 was not used as a collection site in autumn 2011 because TRM 490.5 is a long-term data collection site for the autumn seasons. Historically, the benthic macroinvertebrate community downstream of SQN was sampled at TRM 482.0; however during summer and autumn 2011, benthic macroinvertebrates were sampled at two transects (TRM 481.3 and TRM 483.4) to more accurately depict the health of the downstream benthic community. Benthic grab samples were used to collect samples at equally spaced points along the upstream and downstream transects. During summer 2011, benthic grab samples were collected from five points along the two upstream transects. Autumn 2011 samples were collected from ten points along the transect located at TRM 490.5 and five points at TRM 488.0. Samples were collected from ten points along each downstream transect during summer and autumn 2011. A Ponar sampler (area per sample 0.06 m2) was used for most samples. When heavier substrate was encountered, a Peterson sampler (area per sample 0.11 m2) was used. Collection and processing techniques followed standard VS procedures (OER-ESP-RRES-AMM-21.11; Quantitative Sample Collection - Benthic Macroinvertebrate Sampling with a Ponar Dredge). Bottom sediments were washed on a 533 screen; organisms were then picked from the screen and any remaining substrate. For each sample, organisms and substrate were placed in a sample 9 jar and fixed in formalin. Samples were sent to an independent consultant who identified each organism collected to the lowest possible taxonomic level. Benthic community results were evaluated using seven community characteristics or metrics. Results for each metric were assigned a score of 1, 3, or 5 depending upon how they scored based on reference conditions developed for VS reservoir inflow sample sites. Scoring criteria for upper mainstem Tennessee River reservoirs are shown in Table 5. The scores for the seven metrics were summed to produce a benthic score for each sample site. Potential scores ranged from 7 to 35. Ecological health ratings (7-12 ["Very Poor"], 13-18 ["Poor"], 19-23 ["Fair"], 24-29 ["Good"], or 30-35 ["Excellent"]) were then applied to scores. The individual metrics are shown below: (1) Average number of taxa-This metric is calculated by averaging the total number of taxa present in each sample at a site. Taxa generally mean family or order level because samples are processed in the field. For chironomids, taxa refers to obviously different organisms (i.e., separated by body size, head capsule size and shape, color, etc.). Greater taxa richness indicates better conditions than lower taxa richness. (2) Proportion of samples with long-lived organisms-This is a presence/absence metric which is evaluated based on the proportion of samples with at least one long-lived organism (Corbicula, Hexagenia, mussels, and snails) present. The presence of long-lived taxa is indicative of conditions which allow long-term survival. (3) Average number of EPT taxa-This metric is calculated by averaging the number of Ephemeroptera, Plecoptera, and Trichoptera taxa present in each sample at a site. Higher diversity of these taxa indicates good water quality and better habitat conditions. (4) Percentage as oligochaetes-This metric is calculated by averaging the percentage of oligochaetes in each sample at a site. Oligochaetes are considered tolerant organisms so a higher proportion indicates poorer water quality. (5) Percentage as dominant taxa-This metric is calculated by selecting the two most abundant taxa in a sample, summing the number of individuals in those two taxa, dividing that sum by the total number of animals in the sample, and converting to a percentage for that sample. The percentage is then averaged for the 10 samples at each site. Often, the most abundant taxa differed among the 10 samples at a site.

This allows more discretion to identify imbalances at a site than developing an average for a single dominant taxon for all samples a site. This metric is used as an evenness indicator. Dominance of one or two taxa indicates poor conditions. (6) Average density excluding Chironomids and Oligochaetes-This metric is calculated by first summing the number of organisms, excluding chironomids and oligochaetes, present in each sample and then averaging these densities for the 10 10 samples at a site. This metric examines the community, excluding taxa which often dominate under adverse conditions. A high abundance of non-chironomids and non-oligochaetes indicates good water quality conditions. (7) Zero-samples: Proportion of samples with containing no organisms-This metric is the proportion of samples at a site which have no organisms present. "Zero-samples" indicate living conditions unsuitable to support aquatic life (i.e. toxicity, unsuitable substrate, etc.). Any site having one empty sample was assigned a score of three, and any site with two or more empty samples received a score of one. Sites with no empty samples were assigned a score of five. A similar or higher benthic index score at the downstream site compared to the upstream site is used as basis for determining absence of impact on the benthic macroinvertebrate community related to SQN's thermal discharge. The QA component of VS monitoring shows that the comparison of benthic index scores from 49 paired sample sets collected over the past seven years range from 0 to 14 points, the 75th percentile is 4, the 90th percentile is 6. The mean difference between these 49 paired scores is 3.1 points with 95% confidence limits of 2.2 and 4.1. Based on these results, a difference of 4 points or less is the value selected for defining "similar" scores between upstream and downstream benthic communities. That is, if the downstream benthic score is within 4 points of the upstream score, the communities will be considered similar and it will be concluded that SQN has had no effect. Once again, it is important to bear in mind that differences greater than 4 points can be expected simply due to method variation (25% of the QA paired sample sets exceeded that value). When such occurs, a metric-by-metric examination will be conducted to determine what caused the difference in scores and the potential for the difference to be thermally related. Plankton Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of SQN Samples for analysis of the phytoplankton and zooplankton communities were collected in the mid-channel at four locations, two upstream of SQN at TRM 490.1 and 487.9 and two downstream at TRM 483.4 and 481.1, on August 25 and October 10, 2011. Two replicate samples for both phytoplankton and zooplankton were collected at each site on each sample date. Phytoplankton A low-volume peristaltic pump and tubing apparatus were used to collect integrated water samples along a vertical gradient from the bottom to the top of the photic zone, which was defined as the zone from the surface to twice the Secchi depth reading or from the surface to four meters, whichever was greater. From each of these water samples, a subsample was removed and preserved in glutaraldehyde for taxonomic identification and enumeration of the phytoplankton community. A second subsample was removed from each water sample for analysis of phytopigment (chlorophyll) concentrations. 11 12 Zooplankton Samples for taxonomic identification and enumeration of the zooplankton community were collected using a conical net with 80 µm mesh, towed vertically through the water column from two meters off the bottom to the surface of the reservoir. Samples were preserved in 70% ethyl alcohol (EtOH). Data Analysis Basic summary statistics were used to compare abundances among sites. Two separate measures of diversity, percent similarity and the Bray-Curtis Index of similarity, were used to examine spatial variability within the plankton communities, taking into account both the taxa richness and the uniformity of distribution of individuals among the taxa. Species or taxa richness is expressed simply as the number of species or distinct taxa in the community.

One measure of spatial variability between plankton communities was the calculation of Percent Similarity (PS). To calculate PS, the number of individuals in each species was calculated as the fractional proportion of the total community. For each species, the proportion in community 1 was then compared to the proportion in community 2, and the lower of the two values was tabulated. When all taxa had been compared in this manner, the tabulated list (of the lower of each pair of values) was summed, and this sum defined as the PS of the two communities.

Within the plankton community, spatial variability was also analyzed using hierarchical clustering based on the Bray-Curtis index of similarity. Samples were sorted into groups (clusters) based on the overall resemblance to each other. Cluster analyses were interpreted graphically on dendrograms to relate the similarity of communities among the sampling stations.

Before calculating the measures of diversity for the zooplankton data, the immature specimens identified as Cladocera and Bosminidae (one sample each) were removed; the taxa Eurytemora affinis and Eurytemora sp. were combined in one sample; and in October samples, specimens from all taxa under the group Sididae were combined.

Visual Encounter Surveys (Observations of Wildlife) Two permanent transects were established both upstream and downstream of the SQN thermal discharge. The midpoint of the upstream transect was positioned at the RFAI upstream study area and spanned a distance of 2,100 m within this transect (Figure 3). The downstream transect was collected directly below the power plant and likewise spanned a distance 2,100 m (Figure 4). The beginning and ending point of each transect were marked with GPS for relocation. Transects were positioned approximately 30 m offshore and parallel to the shoreline occurring on both right and left descending banks. Visual Encounter Surveys were conducted to provide a representative sampling of wildlife present during summer (August) and autumn (October). Each transect was surveyed by steadily traversing the length by boat and simultaneously recording observations of wildlife. Sampling frame of each transect generally followed the strip or belt transect concept with all individual species enumerated that crossed the center-line of each transect landward to an area that included the shoreline and riparian zone (i.e., belt width generally averages 60 m where vision is not obscured). Information recorded was identified to the lowest taxonomic trophic level that was observed visually and a direct count of individuals observed per trophic level. If flocks of a species or mixed flock of a group of species were observed, an estimate of the number of individuals present was generated. Time was recorded at the start and end points of each transect to provide a general measure of effort expended. If times varied among transects, it was primarily due to the difficulty in approaching some wildlife species without inadvertently flushing them from basking or perching sites. To compensate for the variation of effort expended per transect, observations were standardized to numbers per minute or numbers per hectare in preparation for analysis. The principal objective and purpose behind the surveys were to provide a preliminary set of observations to verify trophic levels of birds, mammals, amphibians and reptiles have not been affected by thermal effects from the SQN discharge. If trophic levels were not represented, further investigations will be used to target specific species and/or species groups (guilds) in an attempt to determine the cause. Chickamauga Reservoir Flow and SQN Temperature Total daily average discharge from Watts Bar, Apalachia (Hiwassee River), and Ocoee 1 (Ocoee River) dams was used to describe the volume of water flowing past SQN and was obtained from TVA's River Operations database. Water temperature data were also obtained from TVA's River Operations database. Locations of water temperature monitoring stations used to compare water temperatures upstream of SQN intake and downstream of SQN discharge are depicted in Figure 6. Station 14 (TRM 490.4) was used to measure the ambient temperature upstream of the SQN intake. Station 8 (TRM 483.4) was used to measure temperatures downstream of SQN discharge. Water temperatures at both stations were computed as the average of temperatures measured at the 3-, 5-, and 7-ft depths. Thermal Plume Characterization Physical measurements were taken to characterize and map the SQN thermal plume concurrent with biological field sampling during both summer and fall sampling events. The plume was characterized under representative thermal maxima and seasonally expected low flow conditions. Measurements were collected during periods of high power production from SQN, as reasonably practicable, to capture maximum extent of the thermal plume under existing river flow/reservoir elevation conditions. This effort allowed general delineation of the "Primary Study Area" per the EPA (1977) draft guidance defined as the "entire geographic area bounded annually by the locus of the 2°C above ambient surface isotherms as these isotherms are distributed throughout an annual period", ensuring placement of the biological sampling locations within thermally influenced areas. However, it is important to emphasize that the >2ºC isopleth boundary is not a bright line; it is dynamic, changing geometrically in response to changes in ambient river flows and temperatures and SQN operations. As such, samples collected outside of, but generally proximate to the Primary Study Area boundary should not be discounted as non-thermally influenced. Every 1 effort was made to collect biological samples in thermally affected areas as guided by the Primary Study Area definition. Field activities included measurement of surface to bottom temperature profiles along transects across the plume. One transect was located proximate to the thermal discharge point; subsequent downstream transects were concentrated in the near field area of the plume where the change in plume temperature was expected to be most rapid. The distance between transects in the remainder of the Primary Study Area increased with distance downstream or away from the discharge point. The farthest downstream transect was just outside of the Primary Study Area. A transect upstream of the discharge that is not affected by the thermal plume was included for determining ambient temperature conditions. The total number of transects needed to fully characterize and delineate the plume were determined in the field. Temperature profile measurement (surface to bottom) points along a given transect were spaced equally across the river channel. Points began at or near the shoreline from which the discharge originated and continued across the plume [based on surface (0.1 m or 0.3 ft depth) measurements] until the far shore was reached. Measurements along transects were conducted at points 10%, 30%, 50%, 70%, and 90% from the originating shoreline. The distances between transects and measurement points depended on the size of the discharge plume. The temperature measurement instrument (Hydrolab) was calibrated to a thermometer whose calibration is traceable to the National Institute of Standards and Technology. Temperature data were compiled and analyzed to present the horizontal and vertical dimensions of the SQN thermal plume, which was used to demonstrate the existence of a zone of passage under and/or around the plume. Water Quality Parameters at Fish Sampling Sites during RFAI Samples Water quality conditions were measured using a Hydrolab which provided readings for dissolved oxygen (ppm), water temperature (°C and °F), conductivity (µs/cm), and pH. Readings were taken along a vertical gradient from just above the bottom of the river to approximately 0.3 m from the surface at 1- to 2-m intervals. Readings were conducted in the mid-channel at the most downstream and upstream boundaries of the electrofishing sample area at stations upstream and downstream of SQN. Results and Discussion Aquatic Habitat in the Vicinity of SQN Shoreline Aquatic Habitat Assessment Of the sixteen shoreline sections sampled upstream of SQN, 6% (1 transect) rated "Good," 88% (14 transects) rated "Fair," and 6% (1 transect) rated "Poor." The average scores for transects on the left and right descending banks were similar at 22 ("Fair") and 21 ("Fair"), respectively. No aquatic macrophytes were present on either shoreline (Table 6). 2 Of the sixteen shoreline transects sampled downstream of SQN, 19% (3 transects) rated "Good," 56% (9 transects) rated "Fair," and 25% (4 transects) rated "Poor" (Table 7). The average scores for transects on the left and right descending banks were identical at 22 ("Fair"). Aquatic macrophyte coverage averaged 2% on the left descending bank and 5% on the right descending bank (Table 7). River Bottom Habitat Figures 7-10 display substrate percentages as well as water depth at each sample point along each of the 8 transects downstream of SQN. Figures 11-14 display substrate percentages as well as water depth at each sample point along each of the 8 transects upstream of SQN. The three most dominant substrate types encountered along the 8 transects downstream of SQN were mollusk shell (27.6%), silt (19.9%) and clay (16.4%). The three most dominant substrate types encountered along the 8 transects upstream of SQN were silt (51.2%), mollusk shell (18.4%), and bedrock (8.8%). Overall average water depth was similar upstream and downstream of SQN (Table 8). Fish Community During summer 2011, RFAI scores of 41 ("Good") and 38 ("Fair") were recorded for the downstream and upstream sites, respectively (Table 9). Given the downstream site scored higher than the upstream (control), it was concluded that BIP was maintained at the downstream site during summer 2011. During autumn 2011, an RFAI score of 35 ("Fair") was recorded at both the downstream and upstream sites (Table 10). Because both sites received the same score, it can be concluded that BIP was maintained at the downstream site during autumn 2011. For each season, the upstream and downstream sites were compared using the four characteristics of BIP. For the discussion of each characteristic, the downstream site was compared to the upstream site (control) using the RFAI metrics applicable to each characteristic. (1) A biotic community characterized by diversity appropriate to the ecoregion Summer 2011 Total number of indigenous species (> 27 required for highest score for the site downstream of SQN; > 29 required for highest score for the site upstream of SQN) Twenty-eight indigenous species were collected at the downstream site, while 29 indigenous species were collected at the upstream site, resulting in the highest score for the downstream site and a mid-range score for the upstream site for this metric (Table 9). River redhorse and sauger were collected at the upstream site only, while white bass were only collected at the downstream site; all other species were collected at both sites (Tables 11 and 12). Total number of centrarchid species (> 4 required for highest score) 3 Both upstream and downstream sites received the highest possible score for the metric "Number of centrarchid species." The same eight sunfish species were collected at both sites (Tables 9, 11, and 12). Total number of benthic invertivore species (> 7 required for highest score) Only three benthic invertivore species were collected at the downstream site, resulting in the lowest score (1) for the metric "Number of benthic invertivore species." Freshwater drum, logperch, and spotted sucker were collected at both upstream and downstream sites; river redhorse was only collected at the upstream site. As a result of this one additional species, the upstream site received a moderate score of 3 (Tables 9, 11, and 12).

Total number of intolerant species (> 4 required for highest score) Both the upstream and downstream sites received the highest score for the metric "Number of intolerant species." Five of the six intolerant species were collected at both sites; river redhorse was collected at the upstream site only (Tables 9, 11, and 12). Total number of top carnivore species (> 6 required for highest score) Ten top carnivore species were collected at both sites resulting in both sites receiving the highest score (5) for the metric "Number of top carnivore species." White bass were only collected downstream of SQN, while sauger were only collected at the upstream site. All other top carnivore species (black crappie, flathead catfish, largemouth bass, skipjack herring, smallmouth bass, spotted bass, spotted gar, white crappie, and yellow bass) were collected at both sites (Tables 9, 11, and 12).

The overall RFAI score for the downstream site was 41 ("Good") and for the upstream site 38 ("Fair"). These similar scores indicated that the species richness and composition for the five previous metrics described above were similar between sites (Table 9). Autumn 2011 Total number of indigenous species (> 27 required for highest score for site downstream of SQN; > 29 required for highest score for site upstream of SQN) Twenty-five indigenous species were collected at the downstream site, while 27 indigenous species were collected at the upstream site resulting in the mid-range score (3) for this metric at both sites. Longear sunfish and golden redhorse were collected at the downstream site, but not at the upstream site. White crappie, largescale stoneroller, yellow perch, logperch, and walleye were collected only at the upstream site (Tables 10, 13, and 14). Total number of centrarchid species (> 4 required for highest score) Both the upstream and downstream sites received the highest possible score (5) for the metric "Number of centrarchid species." Six of the seven centrarchid species were collected at both sites while white crappie was only collected at the upstream site and longear sunfish only at the downstream site (Tables 10, 13, and 14). Total number of benthic invertivore species (> 7 required for highest score) 4 With only 3 benthic invertivore species each, both sites received the lowest score for the metric "Number of benthic invertivore species." Golden redhorse was collected at the downstream site only and logperch was only collected upstream of SQN (Tables 10, 13, and 14). Total number of intolerant species (> 4 required for highest score) Both the upstream and downstream sites received the mid-range score (3) for the metric "Number of intolerant species." Three of the four intolerant species (skipjack herring, smallmouth bass, and spotted sucker) were collected at each site; longear sunfish was collected downstream of SQN only (Tables 10, 13, and 14). Total number of top carnivore species (> 6 required for highest score) Nine top carnivore species were collected at the downstream site and 11 at the upstream site. However, both the upstream and downstream sites received the highest score (5) for this metric. Walleye and white crappie were only collected at the upstream site; the remaining nine top carnivore species were collected at both sites (Tables 10, 13, and 14). Both sites received the same overall score (35-"Fair") for the five aforementioned RFAI diversity metrics, indicating that fish community diversity during autumn 2011was similar upstream and downstream of SQN (Table 10).

(2) The capacity for the community to sustain itself through cyclic seasonal change Autumn RFAI sampling was conducted downstream of SQN during 1996 and from 1999 through 2011. RFAI scores during this period averaged 41 which rated "Good." With the exception of 1998, autumn RFAI sampling was conducted upstream of SQN from 1993 through 2011. RFAI scores during this period averaged 44 ("Good") (Table 17). The downstream site during summer 2011 received a score of 41 ("Good") and the upstream site scored 38 ("Fair") (Table 9). During autumn 2011, both sites received the same score of 35 ("Fair") (Table 10). These scores are below the historical average for these sites, but fall within the historical range of overall RFAI scores (upstream: 34-51; downstream: 35-48) (Table 17). The composition of the autumn 2011 sample should be indicative of the ability of the fish community to withstand the stressors of an annual seasonal cycle. The numbers of indigenous species collected during autumn RFAI samples downstream of SQN during 1996 and from 1999 through 2011 ranged from 23 to 31 and the average was 27 (Figure 15). During the periods from 1993 to 1997 and 1999 to 2011, the numbers of indigenous species collected during autumn RFAI samples upstream of SQN ranged from 20 to 31 and the average number of indigenous species was 28 (Figure 16). Although the long term average of indigenous species was similar between sites, the upstream site has consistently contained a higher number of species. Regardless, a diverse fish community has continued to persist and has exhibited the ability to sustain itself through cyclic seasonal change at both sites. During summer 2011, 28 indigenous species were collected downstream of SQN and 29 at the upstream site. During autumn 2011, twenty-five indigenous species were collected downstream, and 27 upstream of SQN. These numbers from both summer and autumn were within the 5 average range for this metric when compared to the historical data (Figures 15, 16), indicating that the indigenous fish community was similar upstream and downstream of SQN. Percentage of anomalies (< 2 % required for highest score) The percentage of anomalies (e.g., visible lesions, bacterial and fungal infections parasites, muscular and skeletal deformities, and hybridization) in the summer sample should be indicative of the ability of the fish community to withstand the stressors of an annual seasonal cycle. Both upstream and downstream sites recorded the highest score for this metric during summer 2011 due to a low percentage of observed anomalies (Tables 9 and 10). (3) The presence of necessary food chain species Summer 2011 Insectivores constituted 52.0%, omnivores 35.2%, top carnivores 11.0%, benthic invertivores 1.7%, and planktivores 0.1% of the overall fish sample downstream of SQN during summer 2011. Proportions of insectivores and omnivores met the expectations calculated from historical data for upper mainstem Tennessee River reservoir forebay areas. Proportions of benthic invertivores and top carnivores were below historical averages. Percentages of planktivores were low which is indicative of a healthy environment. No parasitic species were collected (Tables 2 and 3). Trophic levels were represented with 10 insectivorous species, 10 top carnivore species, 7 omnivorous species, 3 benthic invertivore species, and 1 planktivore species (Tables 2, 3, and 11). The number of species for each observed trophic guild met or exceeded expectations, which were calculated from historical data for upper mainstem Tennessee River forebay zones (Tables 2 and 3). At the upstream site during summer 2011, composition by trophic guild was insectivores 52.0%, omnivores 36.3%, top carnivores 8.8%, benthic invertivores 2.6%, and planktivores 0.1% of the overall fish sample. Proportions of planktivores and insectivores exceeded the expectations calculated from historical data for upper mainstem Tennessee River reservoir transition areas, proportions of benthic invertivores met average expectations, proportions of omnivores and top carnivores were less than expected (Tables 2 and 3). Ten insectivorous species, 10 top carnivore species, 7 omnivorous species, 4 benthic invertivore species, and 1 plantivorous species made up the overall fish sample at the upstream site (Tables 2, 3, and 11). The number of species for each trophic guild, except for omnivores, met or exceeded expectations calculated from historical data for upper mainstem Tennessee River transition zones. Omnivore species were less than the expected number (Tables 2 and 3). Overall, trophic guild proportions and composition were similar between sites upstream and downstream of SQN during summer 2011, indicating that the thermal discharge did not affect fish community composition downstream of SQN. Autumn 2011 Insectivores composed 48.3%, omnivores 29.7%, top carnivores 5.2%, planktivores 16.1%, and benthic invertivores 0.8% of the overall fish sample downstream of SQN. Proportions of insectivores, omnivores, and plantivores either met or exceeded expectations calculated from historical data for upper mainstem Tennessee River reservoir forebay areas. Proportions of top 6 carnivores and benthic invertivores were low and did not meet the average proportional expectations. No parasitic species were collected (Tables 2 and 3). Trophic levels were represented with 8 insectivore species, 9 top carnivore species, 6 omnivore species, 1 planktivore species and 3 benthic invertivore species (Tables 2, 3, and 13). The number of species for each observed trophic guild met or exceeded expectations, which were calculated from historical data for upper mainstem Tennessee River forebay zones (Tables 2 and 3). At the upstream site, insectivores constituted 45.6%, omnivores 33.3%, top carnivores 8.2%, benthic invertivores 1.3%, herbivores 0.7%, and planktivores 1.1% of the overall fish sample. Proportions of insectivores and omnivores met the expectations calculated from historical data for upper mainstem Tennessee River reservoir transition areas. Proportions of benthic invertivores and top carnivores were lower than expectations, while proportions of planktivores exceeded historical expectations (Tables 2 and 3). Trophic levels were represented with 8 insectivore species, 11 top carnivore species, 6 omnivore species, 3 benthic invertivore species, 1 herbivore species, and 1 plantivorous species (Table 11). The number of species for each observed trophic guild met or exceeded expectations, which were calculated from historical data for upper mainstem Tennessee River transition zones (Tables 2 and 3).

Overall, trophic guild proportions and composition were similar between sites upstream and downstream of SQN, indicating that the thermal discharge did not affect fish community composition downstream of SQN. (4) A lack of domination by pollution-tolerant species Summer 2011 Number of intolerant species (> 4 required for highest score) Five pollution intolerant species were collected at the downstream site during summer 2011, while 6 were collected at the upstream site. Both sites received the highest RFAI score for this metric (Table 9). Percentage of tolerant individuals (< 31% required for highest electrofishing score upstream and downstream of SQN; < 14% required for highest gill net score downstream of SQN-forebay criteria; < 16% required for highest gill net score upstream of SQN- transition criteria) Both sites received the lowest RFAI score (0.5) for the electrofishing and gill net portions of this metric. At both sites, this was primarily due to collection of a high percentage of bluegill and gizzard shad in the electrofishing samples and collection of large percentages of gizzard shad in the gill net samples (Table 9).

Percentage of omnivores (< 24% required for highest electrofishing score downstream of SQN-forebay criteria; < 22% required for highest electrofishing score upstream of SQN-transition criteria; < 17% required for highest gill net score downstream of SQN; < 23% required for highest gill net score upstream of SQN) Omnivores constituted 31.2% of the electrofishing sample downstream of SQN and 35.1% upstream of SQN. Although only 3.9% difference, the downstream site received a mid-range score and the upstream site a low score for the metric during summer 2011. Proportions of 7 omnivores in the gill net samples at each site were much higher due to large numbers of gizzard shad, resulting in the lowest score for this portion of the metric for both sites (Table 9). The overall proportion of omnivores (electrofishing and gill net combined) was 36.3% at the upstream site and 35.2% at the downstream site. These proportions met expectations for this trophic guild in upper mainstem Tennessee River reservoirs (Tables 2 and 3). Percent dominance by one species (< 25% required for highest electrofishing score downstream of SQN-forebay criteria; < 20% required for highest electrofishing score upstream of SQN-transition criteria; < 15% required for highest gill net score downstream of SQN; < 14% required for highest gill net score upstream of SQN) This metric received the lowest RFAI score for the electrofishing sample at the upstream site, while receiving the mid-range score at the downstream site. Both sites received the lowest score for the gill net sample. The electrofishing samples both downstream and upstream of SQN were dominated by bluegill. Gill net samples at both sites were dominated by gizzard shad (Table 9). Autumn 2011 Number of intolerant species (> 4 required for highest score) Four pollution intolerant species were collected at the downstream site and three at the upstream site during autumn 2011, one more that at the upstream site. Both sites received the mid-range RFAI score for this metric (Table 9).

Percentage of tolerant individuals (< 31 % required for highest electrofishing score upstream and downstream of SQN; < 14% required for highest gill net score downstream of SQN-forebay criteria; < 16% required for highest gill net score upstream of SQN- transition criteria)

The percentage of tolerant individuals in electrofishing samples was almost twice as large (80.8%) at the upstream site compared to the downstream site (42.6%), resulting in the lowest score for the upstream site and mid-range for the downstream site. The difference was mostly due to higher numbers of bluegill in the electrofishing sample at the upstream site. The gill netting samples contained high percentages of gizzard shad and received the lowest scores at both sites (Table 10). Percentage of omnivores (< 24% required for highest electrofishing score downstream of SQN-forebay criteria; < 22% required for highest electrofishing score upstream of SQN-transition criteria; < 17% required for highest gill net score downstream of SQN; < 23% required for highest gill net score upstream of SQN) Omnivores made up 27.5% of the electrofishing sample downstream of SQN and 31.9% upstream of SQN, resulting in a mid-range score for this metric at both sites. Proportions of omnivores in the gill net samples at each site were higher due to large numbers of gizzard shad, resulting in the lowest score for this portion of the metric for both sites. The overall proportion of omnivores (electrofishing and gill net combined) at the upstream site was 33.3% and 29.7% at the downstream site (Table 10). These proportions met expectations for this trophic guild in upper mainstem Tennessee River reservoirs (Tables 2 and 3).

8 Percent dominance by one species (< 25% required for highest electrofishing score downstream of SQN-forebay criteria; < 20% required for highest electrofishing score upstream of SQN-transition criteria; < 15% required for highest gill net score downstream of SQN; < 14% required for highest gill net score upstream of SQN) The downstream site received the mid-range RFAI score for the electrofishing sample and the lowest score for the gill net sample. The upstream site received the lowest score for this metric for both electrofishing and gill net samples. The electrofishing sample downstream of SQN was dominated by Mississippi silversides (non-indigenous), while the electrofishing sample upstream of SQN was dominated by bluegill. Gill net samples at both sites were dominated by gizzard shad (Table 10).

Traditional Analyses Summer 2011 One species richness parameter (number of insectivore species) was statistically (P<0.05) higher upstream than downstream of SQN. Although the differences were not significant, seven of the other nine species richness measures were also higher upstream of the plant (including non-indigenous species). Numbers of omnivore and tolerant species were higher downstream, but the differences were not significant. Of the parameters comparing CPUE, two, total CPUE and CPUE of intolerant individuals, were statistically higher at the site upstream of SQN than the downstream. Seven of the remaining eight parameters were higher upstream than downstream, but the differences were not significant. CPUE of top carnivores was slightly higher at the downstream site. Both diversity values showed no statistical difference between sites, although both were higher at the upstream site (Table 15). Autumn 2011 All species richness parameters were similar (no statistical difference) upstream and downstream of SQN. Six of the ten species richness measures were higher at the downstream site (including numbers of omnivore and tolerant species), while three were higher at the upstream site; mean numbers of benthic invertivore species were the same at both sites. Two of the ten parameters comparing CPUE, total CPUE and CPUE of non-indigenous individuals, were statistically higher at the downstream site (Table 16). These significant differences were driven by the higher numbers (approximately nine times more) of the non-indigenous Mississippi silverside collected at the downstream site (Tables 13 and 14). All other CPUE parameters showed no statistical difference between sites. CPUEs of insectivores, omnivores, top carnivores, and thermally sensitive individuals were also higher at the downstream site, but differences were not statistically significant. The remaining four parameters (CPUE of benthic invertivores, indigenous, tolerant, and intolerant individuals) were higher at the upstream site. Both diversity values were slightly higher at the downstream site, but differences were not significant (Table 16).

9 Fish Community Summary In conclusion, evaluation of the five characteristics of BIP and their respective metrics and traditional analyses indicated the downstream site was similar to the upstream site and that a balanced fish community existed at the site downstream of SQN in summer and autumn 2011. Summer 2011 Seven of the 12 RFAI metrics received equal scores at both sites for the summer of 2011. The upstream site received a lower score for the metrics "Number of indigenous species," "Percent dominance by one species," "Percent top carnivores," and "Percent omnivores" (Table 9). Twenty-nine indigenous species were collected at the upstream site and 28 were collected at the downstream site. No statistical difference existed in numbers of indigenous species and CPUE of indigenous individuals between sites (Table 15). Thirty-one resident important species (RIS) were collected at the upstream site compared to 29 at the downstream site (Tables 11 and 12). RIS are defined in EPA guidance as those species which are representative in terms of their biological requirements of a balanced, indigenous community of fish, shellfish, and wildlife in the body of water into which the discharge is made (EPA and NRC 1977). RIS often include non-indigenous species. The same three aquatic nuisance (non-indigenous) species, common carp, yellow perch, and Mississippi silverside, were collected at both sites (Tables 11 and 12); CPUE of these three species was similar between sites (Table 15).

The same two thermally sensitive species (spotted sucker and logperch) were collected at both sites (Tables 11 and 12) and were collected in similar densities (Table 15). Water temperatures greater than 32.2°C (90°F) are known to be the avoidance level and/or lethal level to these species (Yoder et al. 2006).

Four commercially valuable species were collected at the downstream site and five were collected at the upstream site. Twenty-four recreationally valuable species were collected at the upstream site, while 25 were collected at the downstream site (Tables 11 and 12). Autumn 2011 Nine of the 12 RFAI metrics received the same scores at both sites. The upstream site received a lower score for the electrofishing portion of the metric "Percent dominance by one species" and "Percent tolerant individuals", while the downstream site received a lower score for the metric "Percent top carnivores" (Table 10). Twenty-eight indigenous species were collected at the upstream site, while 25 were collected at the downstream site. Numbers of indigenous species and indigenous CPUEs at the downstream site were similar to those at the upstream site (Table 16). Thirty resident important species were collected at the upstream site compared to 27 resident important species at the downstream stations (Tables 13 and 14). Representative important species are defined in EPA guidance as those species which are representative in terms of their biological requirements of a balanced, indigenous community of fish, shellfish, and wildlife in the body of water into which the discharge is made (EPA and NRC 1977). 10 Three aquatic nuisance species (common carp, yellow perch, and Mississippi silverside) were collected at the upstream site, while two aquatic nuisance species (common carp and Mississippi silverside) were collected at the downstream site (Tables 13 and 14). Although the numbers of non-indigenous species was similar between sites, CPUE of non-indigenous individuals was significantly higher at the downstream site (Table 16). This was due to a large number of Mississippi silversides collected at the downstream site (917, or 33.5% of total catch) compared to the upstream site (124, or 6.3 % of total catch) (Tables 13 and 14). This is a schooling fish species and is commonly collected in large numbers. Two thermally sensitive species (spotted sucker and logperch) were collected upstream, while one (spotted sucker) was collected downstream (Tables 13 and 14). CPUE of these species was similar between sites (Table 16). Water temperatures greater than 32.2°C (90°F) are known to be the upper avoidance level or lethal to the aforementioned species (Yoder et al. 2006). Thirteen commercially valuable species were collected at downstream site and 11 at the upstream site. Twenty-four recreationally valuable species were collected at the upstream site, while 19 were collected at the downstream site (Tables 13 and 14). As discussed above, RFAI scores have an intrinsic variability of +/-3 points. This variability comes from various sources, including annual variations in air temperature and stream flow; variations in pollutant loadings from nonpoint sources; changes in habitat, such as extent and density of aquatic vegetation; natural population cycles and movements of the species being sampled (TWRC, 2006). Another source of variability arises from the fact that nearly any practical measurement, lethal or non-lethal, of a biological community is a sample rather than a measurement of the entire population. As long as scores are within the 6-point range, there is no certainty that any real change at a site has occurred or difference between sites exists beyond method variability. It should be noted that the upstream site is scored using transition criteria and the downstream site using forebay criteria (Table 4). More accurate comparisons can be made between sites that are located in the same reservoir zone (i.e., transition to transition). Due to the location of SQN, it is not possible to have an upstream and downstream site within the same reservoir zone. SQN is located at the downstream end of the transition zone on Chickamauga Reservoir; therefore, the downstream site is located in the upstream section of the forebay. The physical and chemical composition of a forebay is often different than that of a transition zone; consequently, inherent differences exist among the aquatic communities (e.g. species diversity is often higher in a transition zone than a forebay).

Through the years sampled, the upstream site averaged a score of 44 ("Good") while the downstream site averaged a score of 41 ("Good"), indicating the sites were similar annually and that the SQN heated effluent is not adversely affecting the fish community in the vicinity of the plant (Table 17). RFAI scores are presented for the Chickamauga Reservoir inflow site (TRM 529.0), the forebay site (TRM 472.3), and the Hiwassee River Embayment site (HiRM 8.5) to provide additional information on the health of the fish community throughout the reservoir; however, aquatic communities at these sites are not affected by SQN thermal discharges and are not used to determine BIP in relation to SQN. The average RFAI scores at these three sites among all years sampled have remained in the "Good" range (Table 17). 11 Individual metric scores, overall RFAI scores, species collected, and catch per effort from electrofishing and gill netting for the upstream and downstream sampling sites at SQN during 1999 through 2010 are included in Shaffer et al., 2010 and Simmons, 2011. Benthic Macroinvertebrate Community Summer 2011 During summer 2011, RBI scores at the downstream transects TRM 481.3 and TRM 483.4 were 27 ("Good") and 29 ("Good"), respectively, and were slightly higher than those at upstream transects TRM 488.0 and TRM 490.5 [27 ("Good") and 23 ("Fair"), respectively] (Table 18). A difference of 4 points or less between upstream and downstream stations is used to define "similar" conditions between the two sites. Because the average of the downstream sites (28) scored three points higher than that of the upstream sites (25) and rated "Good", it can be determined that BIP was maintained. For the discussion of each RBI metric, the downstream site was compared to the upstream control site. Average number of taxa (> 5 required for highest score-forebay criteria; > 6.6 required for highest score-transition criteria) The downstream sites (forebay) averaged 11.2 taxa, while the upstream sites (transition) averaged 7.1 taxa; all sites received the highest score for this metric (Table 18). Proportion of samples with long-lived organisms (> 0.8 required for highest score-forebay criteria; > 0.9 required for highest score-transition criteria) The observed values for the metric "Proportion of samples with long-lived organisms" (e.g., Corbicula, Hexagenia, mussels, and snails) were 0.8 at both downstream transects and both sites scored 3 (mid-range). Upstream of SQN, all samples at the transect at TRM 488.0 contained long-lived organisms (1.0) resulting in a score of 5, while TRM 409.5 received a score of 1 with only 40% of samples containing long-lived organisms (Table 18). Snail proportions, in particular, were higher downstream of SQN as compared to those upstream (Figure 19). Average number of EPT taxa (> 0.9 required for highest score-forebay criteria; > 1.4 required for highest score-transition criteria) The average number of EPT taxa present in each sample were 0.9 and 1.2 at the downstream transects, resulting in scores of 3 and 5, respectively. At the upstream transects TRM 488.0 and TRM 490.5, average number of EPT taxa was 0.8 (score: 3) and 0.2 (score: 1), respectively (Table 18). Ephemeroptera (mayflies) and Trichoptera (caddisflies) proportions were slightly higher at the downstream sites as compared to the upstream sites (Figure 17). Average proportion of oligochaete individuals (< 21.0 required for highest score-forebay criteria; < 11.0 required for highest score-transition criteria) The average proportion of oligochaete individuals at the downstream sites were 35.6% (score of 3) and 54.4% (score of 1). The upstream sites had smaller percentages of samples containing oligochaetes (15.5% at TRM 488.0 and 7.2% at TRM 490.5) and therefore, received higher scores of 3 and 5, respectively (Table 18). 12 Average proportion of total abundance comprised by the two most abundant species (< 81.7 required for highest score-forebay criteria; < 77.8 required for highest score-transition criteria) Both downstream sites received scores of 5 with proportions of 73.7% (TRM 481.3) and 75.5% (TRM 483.4) of the samples comprising the two most abundant taxa (chironomids and oligochaetes). At the upstream sites TRM 488.0 and TRM 490.5, 82.8% and 86.4% of the total abundance, respectively, was comprised of the two most abundant taxa (chironomids and oligochaetes) resulting in mid-range scores for both sites (Tables 18 and 20). Average density excluding chironomids and oligochaetes (> 249.9 required for highest score-forebay criteria; > 609.9 required for highest score-transition criteria) At the downstream sites, average densities of organisms excluding chironomids and oligochaetes were 235/m2 and 525/m2, resulting in scores of 3 and 5, respectively. At the sites upstream of SQN, densities excluding chironomids and oligochaetes were 470/m2 and 396.7/m2 and both sites received scores of 3 (Table 18). Proportion of samples containing no organisms (0 required for highest score) There were no samples at any site upstream and downstream of SQN which were void of organisms. Therefore, all sites received the highest score for this RBI metric during summer 2011 (Table 18).

In conclusion, during the summer of 2011 downstream sites scored the same or higher than the upstream site on all metrics except "Average number of oligochaetes" indicating BIP was maintained downstream of SQN. Autumn 2011 Autumn RBI scores for downstream were 29 ("Good"), 27 ("Good"), while the upstream site scored 19 ("Fair") (Table 18). A difference of 4 points or less between upstream and downstream stations is used to define "similar" conditions between the two sites. Because the downstream site scored 8 to 10 points higher and rated "Good," it can be determined that BIP was maintained. For the discussion of each RBI metric, the downstream site was compared to the upstream control site. Average number of taxa (> 5 required for highest score-forebay criteria; > 6.6 required for highest score-transition criteria) Averages of 7.8 and 13.6 taxa were observed for sites downstream of SQN. The site upstream of SQN averaged 6.6 taxa per sample. The downstream sites both received the highest score for this metric, while the upstream site received the mid-range score (Table 18). Proportion of samples with long-lived organisms (> 0.8 required for highest score-forebay criteria; > 0.9 required for highest score-transition criteria) The metric "proportion of samples with long-lived organisms" (Corbicula, Hexagenia, mussels, and snails) scored 3 at both downstream sites with proportions of 0.7 and 0.8. The proportion of samples with long-lived organisms (0.8) was similar at the upstream site and therefore, also a score of 3 (Table 18). 13 Average number of EPT taxa (> 0.9 required for highest score-forebay criteria; > 1.4 required for highest score-transition criteria) The average numbers of EPT taxa present per sample at each of the downstream sites were 1.0 and 0.9, resulting in scores of 5 and 3, respectively. The site upstream of SQN received a score of 1 with 0.5 EPT taxa per sample (Table 18). Ephemeroptera (mayflies) and Trichoptera (caddisflies) proportions were higher at the downstream sites as compared to the upstream site (Figure 19). Average proportion of oligochaete individuals (< 21.0 required for highest score-forebay criteria; < 11.0 required for highest score-transition criteria) At the downstream sites, average proportion of oligochaete individuals in each sample was 29.4% at TRM 481.3 and 48.1% at TRM 483.4 resulting in scores of 3 and 1, respectively. The upstream site received a score of 3 with a proportion of 14.8% (Table 18). Average proportion of total abundance comprised by the two most abundant species (< 81.7 required for highest score-forebay criteria; < 77.8 required for highest score-transition criteria) During autumn 2011, 78.6% of the total abundance at TRM 481.3 was comprised of the two most abundant taxa (chironomids and oligochaetes). The two most abundant taxa at TRM 483.4 were oligochaetes and flatworms (Planariidae) and constituted 77% of the total abundance. Both downstream sites received the highest score of 5. At the upstream site TRM 490.5, 84.5% of the total abundance was comprised by the two most abundant taxa, chironomids and fingernail clams (Sphaeriidae), resulting in a mid-range score for this metric (Tables 18 and 20). Average density excluding chironomids and oligochaetes (> 249.9 required for highest score-forebay criteria; > 609.9 required for highest score-transition criteria) At the downstream sites, average densities excluding chironomids and oligochaetes were 181.7/m2 and 1,685/m2 resulting in scores of 3 and 5, respectively. Average density excluding chironomids and oligochaetes at the upstream site was 263.3/m2, resulting in the lowest score for this metric (Table 18). Proportion of samples containing no organisms (0 required for highest score) There were no samples at any site which were void of organisms. Therefore, all sites received the highest score for this RBI metric during autumn 2011 (Table 18). In conclusion, during the autumn of 2011, downstream sites scored the same or higher on all the metrics indicating a BIP of benthic macroinvertebrates was maintained downstream of SQN (Table 18). The low score at the upstream site (19) was lower than expected based on historical scores; however, similarly low scores of 21 and 17 were observed in 2007 and 2008, respectively. A possible reason for the low score at the upstream site could be pollution impacts from the Hiwassee River, which enters the Tennessee River 9 miles upstream of TRM 490.5. Individual RBI metric ratings and field scores from TRM 482.0 (downstream) and TRM 490.5 (upstream) are listed in Table 21 for comparison of results from 2000 to 2010. Although downstream sites sampled in 2011 were proximate to the transect sampled from 2000-2010 14 (TRM 482.0), 2011 RBI scores cannot be directly compared to those from 2000 to 2010 without inference. RBI scores for the inflow, forebay, and Hiwassee River embayment sites are included in Table 19 to provide additional information on the overall health of the benthic macroinvertebrate community in Chickamauga Reservoir. RBI scores have averaged "Good" for the inflow and forebay sites and "Fair" for the Hiwassee River embayment over all sample years. Plankton Community Detailed results of taxa collected and estimates of sample density are provided in Table 26 (phytoplankton) and in Table 33 (zooplankton). Phytoplankton Summer 2011 Figure 18 indicates that average phytoplankton densities decreased progressively from TRM 490.7 (the most upstream site) to TRM 483.4 (immediately downstream of the diffusers). Phytoplankton density was lowest at TRM 483.4 and increased further downstream at TRM 481.1 to concentrations similar to the most upstream site. Numerically, cyanophytes were the dominant taxa (96 to 99 percent; Table 22, Figure 18) at all sites, with a prevalence of Cyanogranis and several taxa in the family Chroococcaceae (Table 26). Considered as a percentage of total biovolume, bacillariophytes (diatoms) were more dominant (Figure 19). Total taxa richness for paired replicate samples ranged from 43 to 49, and the percentage of taxa shared between replicates samples ranged from 52.1 to 76.7 percent (Table 23). However, of the 67 taxa collected in August, seven cyanophyte taxa were common to all replicate samples and accounted for 86 to 95 percent of the total population (Tables 24, 26). Percent Similarity coefficients (ranging from 75 to 87; Table 25) and Bray-Curtis similarity coefficients (BCe) were high (ranging from 0.78 to 0.81, Figure 25), indicating that the structure of the phytoplankton community was similar at all sites. The cluster analysis indicated that the communities at TRM 481.1 and TRM 487.9 were the most similar, followed by TRM 483.4 and 490.7. No upstream to downstream trend was evident. Autumn 2011 Total population densities in October were much lower compared to those in August, and the spatial trend was reversed. That is, phytoplankton density increased progressively from the most upstream site (TRM 490.7) to a maximum density at the diffuser (TRM 483.4), then decreased again slightly at the site further downstream at TRM 481.1 (Figure 20). Bacillariophytes (diatoms) were numerically dominant (36 to 63 percent; Table 22, Figure 20) at all sites and comprised approximately 74 to 91 percent of the total biovolume (Figure 21). Cryptophytes (Cryptomonas) were subdominant (21 to 36 percent) and the composition of chlorophytes and cyanophytes ranged from 6 to 16 percent. Total taxa richness for paired replicate samples ranged from 27 to 32 at the three lower sites, but only 19 taxa were collected at 15 TRM 490.7. The number of taxa shared between replicate samples ranged from 50.0 to 57.9 percent (Table 23). However, of the 38 taxa collected in October, nine were common to all samples and accounted for 74 to 97 percent of the total population. A mix of cyanophyte taxa often comprised more than 10 percent of the population in any given sample, but seldom was the same taxon present in both replicates, and no single taxon was represented in all samples (Tables 24, 26). October PS coefficients among the three lower sites were relatively high (71 to 80), while the PS coefficients for TRM 490.7 were notably lower (63 for each site comparison) (Table 25). By this measure, the communities downstream (TRM 487.9, 483.4, and 481.1) were relatively similar, but the community at the most upstream site (TRM 490.7) showed the greatest dissimilarity to any other. The same taxa (Aulacoseira, Fragilaria, and Cryptomonas) were dominant at each site, but TRM 490.7 had lower taxa richness and the dominant taxa comprised a greater percentage of the overall population (Table 27). The Bray-Curtis similarity coefficients (BCe) (0.64 to 0.73) indicate that phytoplankton community structure was slightly more dissimilar among sites in October than in August, which is supported by the PS coefficients. TRM 483.4 and TRM 487.9 formed the first cluster (BCe, 0.73), followed by a secondary cluster with TRM 481.1 (BCe, 0.68). TRM 490.7 clustered last, indicating this site was least similar in terms of taxa shared and taxa abundances (Figure 26). Overall, TRM 490.7 had higher composition of diatoms and lower composition of chlorophytes and cryptophytes compared to the three downstream locations (Table 22). Chlorophyll Chlorophyll a concentrations differed among the four sites in samples collected in both August and October (Table 28, Figure 22). Upstream to downstream differences in chlorophyll a concentrations closely paralleled phytoplankton density, but as expected, the chlorophyll a concentration was more closely associated with biovolume (Figures 19, 21). August data show TRM 483.4 had the lowest concentrations (6.0 µg/l) followed by TRM 490.7 (9.5 µg/l). Chlorophyll a concentrations were similar for TRM 481.1 (12 µg/l) and TRM 487.9 (14 µg/l) (Table 28). Decreased concentrations at TRM 483.4 are supported by findings of reduced phytoplankton cell densities and biovolume at this location (Table 26, Figure 19). October chlorophyll a concentrations increased progressively from TRM 490.7 to TRM 483.4, and then decreased at TRM 481.1 to a concentration similar to that of the uppermost site (TRM 490.7). Again, the spatial differences are supported by the phytoplankton density (Table 26) and biovolume data (Figure 21). Zooplankton Overall, 35 zooplankton taxa were represented in the samples collected. The number of taxa represented in each major group was 10 to 12, with the exception of the Bivalvia, for which only 2 taxa were represented (Table 31). Notably, taxa richness for individual samples ranged from 8 to 16, but the number of taxa shared between replicates ranged from only 3 to 8 (21.4 to 66.7 percent) due to substantial variability in the presence/absence of less abundant taxa (Tables 30, 33). In the samples collected during both August and October, four to five taxa comprised the majority (approximately 90 to 99 percent) of the populations at each of the four sites. The 16 dominant taxa were the cladocerans Bosmina longirostris and Diaphanosoma birgei (not present in October); copepods in the orders Calanoida and Cyclopoida; and the rotifer Conochilus unicornis (Table 33). Summer 2011 Data from August samples showed that zooplankton densities were notably higher at sites downstream of the diffusers. Densities increased progressively from the most upstream site (TRM 490.7) to the highest density at TRM 483.4, just downstream of the diffusers, then decreased slightly at TRM 481.2. The lower overall density at TRM 481.2 was largely due to the collection of fewer rotifers. TRM 483.4 had higher rotifer group density than all other sites. TRM 481.1 had the highest density of cladocerans (Figure 23). Cladocerans were numerically dominant (49 to 68 percent; Table 29, Figure 23) at all sites. The composition of copepods and rotifers was generally similar (15 to 26 percent) among all sites except TRM 481.1. Rotifers comprised only two percent of the population at TRM 481.1 and copepods comprised a slightly higher percentage (30 percent) compared to other sites. Total taxa richness for paired replicate samples was relatively low, ranging from 8 to 14. Taxa richness was highest (14) at TRM 481.1, with sites upstream having only 8 to 9 taxa represented (Table 30). August PS coefficients (70 to 80) were relatively high among the three most upstream sites, indicating similar community structure. TRM 481.1 had somewhat low PS coefficients with TRM 483.4 and TRM 487.9 (63 and 69, respectively), due largely to lower composition of copepods in the order Calanoida and the rotifer Conochilus unicornis at TRM 481.1. The PS coefficient (75) for TRM 481.1 and TRM 490.7 was relatively high (Table 32).

Bray-Curtis Similarity yielded similar results. Coefficients ranged from 0.65 to 0.80. TRM 483.4 and TRM 490.7 were the most similar, with a high coefficient of 0.80. These sites formed a secondary cluster with TRM 487.9 (BCe, 0.72). TRM 481.1 clustered last (BCe, 0.65), indicating this site was least similar to the other sites in terms of taxa shared and taxa abundances (Figure 27). Autumn 2011 In October, average zooplankton densities were highest at TRM 481.1, but variability between the replicate samples was high. TRM 490.7 had the second highest population density. Densities were similar at TRM 483.4 and TRM 487.5 (Figure 24). Comparable to findings in August, cladocerans were numerically dominant (44 to 71 percent) at all sites and copepods were subdominant (23 to 40 percent). However, the composition of rotifers was higher at TRM 481.1 (16 percent) than at sites upstream (2 to 6 percent), which is the reverse of findings in August (Table 29). Total taxa richness ranged from 12 to 16 at the three most upstream sites, but only 9 taxa were collected at TRM 481.1 (Table 30). October PS coefficients (72 to 93) were higher among sites than in August, but yielded similar findings, with the lowest PS coefficients (72 to 83) for TRM 481.1 (Table 32). However, the density and composition of copepods in the order Calanoida and the rotifer Conochilus unicornis were highest at TRM 481.1 in October and lowest in August (Table 33). These taxa contributed to the dissimilarity between TRM 481.1 and other sites exhibited during both sample dates. 17 Bray-Curtis Similarity yielded similar results. Coefficients ranged from 0.63 to 0.70. TRM 483.3 and TRM 487.9 formed the first cluster (BCe, 0.70), indicating the communities at these sites were the most similar of the four. These sites form a secondary cluster with TRM 490.7 (BCe, 0.68). TRM 481.1 clustered last, indicating greater dissimilarity with other sites (Figure 28).

Plankton Summary The results of the Phytoplankton and Zooplankton studies at SQN during 2011 generally support findings from previous studies, which are presented in the section following this summary. Phytoplankton Phytoplankton data indicated that quantitative characteristics (total and group cell densities) differed among sites in both August and October, but there were few differences in community structure among the four sample sites on either date. Notably, the reduced phytoplankton densities, biovolume, and chlorophyll concentrations at TRM 483.4 in August could be interpreted as an effect from SQN diffuser discharge. Previous studies have indentified reduced phytoplankton densities and chlorophyll concentrations (biovolume was not measured) at TRM 483.4 due to the diffusers mixing water from the bottom - containing low phytoplankton densities - with water of the upper strata that typically contain greater densities. Previous studies have also documented that when phytoplankton reductions have occurred at TRM 483.4 in apparent relation to diffuser mixing, densities recovered within a few miles downstream of the diffusers. Likewise, in August, phytoplankton parameters (density, biovolume, and chlorophyll) showed lowest values at TRM 483.4, and then increased at TRM 481.1 to levels similar to those found upstream of the diffuser. Additionally, previous studies have documented that when differences have occurred in phytoplankton communities among locations, these differences typically have been either increases or decreases in organism densities, not compositional changes in the community. This was supported in the current study. In both August and October, the two independent measures of diversity indicated relatively high levels of similarity among sites upstream and downstream of the diffusers, even though population densities differed. Only TRM 490.7 exhibited lower similarity when compared with the other sites, and then only in October. However, we do not consider this dissimilarity related to the operation of SQN.

Zooplankton Zooplankton data indicated that quantitative differences existed among sites in both August and October, but there were no upstream to downstream trends in population densities that provided definitive evidence of an effect from the operation of SQN. In August, zooplankton densities were highest at TRM 483.4, just downstream of the diffuser, and densities at both downstream sites were higher compared to those of the upstream sites. In October, zooplankton densities were highest at TRM 481.1, the most downstream site. Densities at TRM 483.4 and TRM 487.9 were very similar, but were lower than those at the most upstream and most downstream sites. As with phytoplankton, compositions of the zooplankton communities were generally similar among sites, even though population densities differed. Overall, TRM 481.1 was more dissimilar to the other sites in both August and October. This was due in part to higher population densities at TRM 481.1, but interestingly, the taxa that contributed most to the 18 dissimilarity of this site were the same in both months. In August, TRM 481.1 had the lowest density and composition of calanoid copepods and of the rotifer Conochilus unicornis. In October, the same site had the highest density and composition of these taxa. Although the reduced densities of these taxa in August may have been due in part to operation of SQN, the greater abundance of organisms at TRM 481.1 - including the highest densities of copepods and cladocerans among all four sites - suggests that the majority of the reduction is more likely related to other variables. One such variable is the "patchy" nature of plankton distributions, as evidenced by the high variability in density of some taxa observed between replicate samples collected at each site. Such patchy distributions have been described in previous studies, and are discussed further in the review following this summary. Review of Previous Plankton Studies Previous plankton studies around SQN were conducted with the objective of evaluating the effects of SQN operations on plankton, but these were not controlled experiments (i.e. experiments designed to keep all variables constant except the test factor - in this case, the power plant). Instead, the program monitored a dynamic system: even without the influence of SQN, differences between the control locations (upstream of the plant) and the test locations (downstream of the plant) were expected due to other possible variables. One possible variable is the longitudinal point, or transition zone, where water velocities become sufficiently low for phytoplankton to remain in the photic zone long enough to sustain growth and reproduction. The location of this transition zone in the reservoir is dependent on flow conditions, and it might fluctuate upstream or downstream daily or even hourly, as inflows from the Hiwassee River and releases from Chickamauga and Watts Bar dams vary (Figures 29 and 30 - hourly average flows). Other variables may include but are not limited to: reservoir stratification; inflow from the overbanks and other highly productive areas; phase of population (and community) growth; the patchy nature of plankton distribution; differences in depth among sample locations; travel time between sample locations; and light penetration. Like the transition zone, many of the factors in this list are also directly or indirectly related to flow conditions. Each of the factors listed here has an important influence on plankton, and each contributes to the composition of the community sampled at each location. Studies to date have documented that when differences in phytoplankton and zooplankton communities occurred among sample locations, these differences typically were either increases or decreases in organism densities, not community changes. Studies have shown that downstream increases were more commonly observed under relatively high reservoir flows (e.g., 30,000 cfs), while when reservoir flows were quite low (i.e., <10,000), decreases in downstream plankton densities were expected, particularly at the diffuser location (TRM 483.4). Greater variability in plankton densities was observed at intermediate flows. The studies also indicated that reductions in phytoplankton densities were caused by different mechanisms than were reductions in zooplankton densities. The mechanism most likely responsible for reductions of phytoplankton densities and of chlorophyll concentrations is mixing of the water column at the diffuser location. In-plant plankton studies conducted in 1987 (TVA, 1988) and in 1988 (TVA, 1989) indicated some reduction in cell densities may have occurred as water was entrained through the CCWS, but most of the reductions observed at TRM 483.4 were due to mixing caused by the diffusers. The cooling water that is withdrawn from the lower strata near the skimmer wall has naturally low 19 concentrations of phytoplankton compared to upper strata. This water is carried through the CCWS, heated, and discharged through the diffusers. The momentum from being discharged through the diffuser ports, plus the buoyancy from the added heat, cause this water to rise and mix with ambient water near the diffusers. The water withdrawn from and discharged at the bottom, already low in phytoplankton, and the mixing which redistributes the phytoplankton concentrated near the surface, are reflected as reduced phytoplankton concentrations for TRM 483.4 at most strata. Previous studies have also documented that when phytoplankton reductions occurred at TRM 483.4 in apparent relation to diffuser mixing, recovery was realized by TRM 478.2 (previous study site). Furthermore, special biweekly surveys conducted from April to October, 1989, showed downstream phytoplankton concentrations recovered to levels similar to those above the diffuser within 1-2 river miles (TVA, 1990). Reductions in zooplankton densities appear to be caused by a more complex set of factors, including passage through the SQN CCWS. In-plant studies have shown substantial reductions in zooplankton densities during passage through the CCWS, even without heat (TVA, 1988). Zooplankton densities were significantly lower in the diffuser pond samples compared to intake samples, and essentially all zooplankton examined from the diffuser pond were immobile and presumed dead (TVA, 1989). Discharge of the water with reduced number of zooplankters would result in some reduction in density at the diffuser location (TRM 483.4). However, these reductions alone were not sufficient to account for the magnitude of decreased density typically observed, particularly since many of the dead zooplankters would still be discharged and included in the enumeration from TRM 483.4. These results indicate that some other factor or combination of factors, in addition to mixing at the diffuser, must be involved in reduced zooplankton densities at the diffuser site. One possible factor that became evident as more studies were conducted is the complex hydraulics in the vicinity of the diffuser discharge. The hydraulics of this area were likely complex even before SQN was constructed, due to the narrowing and deepening of the channel compared to upstream, and to the presence of an overbank (typically highly productive) with its point of inflow to the channel just upstream of where the channel narrows and deepens. Construction of SQN, including the addition of an underwater dam that occupies about half of the cross-sectional area of the river channel and the installation of the diffusers with buoyant discharge, further complicated the hydraulics in this area. Obviously, collection of representative samples from this area is difficult due to varying contributions of several factors, including reduced densities in the discharge water, increased densities in water entering the channel from the upstream overbank, and physical mixing of the zooplankton (which typically are not evenly distributed in the water column) in the ambient channel water. Although some of the reductions in zooplankton densities are due to operation of SQN, it has not been possible to specify the magnitude of that reduction separate from that due to other variables. Visual Encounter Survey/Wildlife Observations Summer 2011 Thirty-three individuals composing 11 bird species and 1 mammal species were observed along shoreline transects (RDB and LDB) upstream of SQN. Along shoreline transects downstream of SQN, 51 individuals constituting 10 bird and one mammal species were observed. Bird species 20 observed both upstream and downstream of SQN included unidentified species of swallow, belted kingfisher, osprey, and great blue heron. American crow, turkey vulture, red-winged blackbird, and an unidentified duck species were only observed at the transects upstream of SQN, while wood duck, double-crested cormorant, European starling, and green heron were only observed along transects downstream. White-tailed deer was the only mammal species observed during the survey and was observed in equal numbers (4 individuals) upstream and downstream of SQN (Table 35). Autumn 2011 Four species of birds comprising 9 individuals were observed along transects upstream of SQN. Downstream of SQN, 1,024 birds composing 17 species and one species of mammal were observed. Three of the four bird species (great blue heron, belted kingfisher, and an unidentified songbird species) observed upstream were viewed downstream; an unidentified wren species was observed along transects upstream of SQN only. Fourteen bird species were only observed downstream of SQN and included blue jay, northern mockingbird, double-crested cormorant, American coot, American widgeon, pied-billed grebe, mallard, tufted titmouse, killdeer, wood duck, black-crowned night heron, gadwall, green-winged teal, and an unidentified sandpiper species. The only mammal species observed at the downstream transect was eastern gray squirrel (1 individual) (Table 35). In summary, the wildlife community downstream of SQN was similar to that upstream during summer 2011. During the autumn 2011 survey, species richness and total numbers observed were significantly higher downstream of SQN. Chickamauga Reservoir Flow and Temperature Near SQN Total average daily flows from Watts Bar Dam, Ocoee No. 1 Dam, and Appalachia Dam from October 2010 to November 2011 and historical daily average flows from 1976 through 2010 are shown in Figure 31. Daily average flows from October 2010 to November 2011 were similar (total daily average flows averaged 6% higher) to historical daily average flows, but were below the historical averages during the summer and autumn sampling periods (Figure 31). Daily average water temperatures recorded upstream of the SQN intake and downstream of SQN discharge, October 2010 through November 2011, are shown in Figure 20. Water temperatures remained within permitted limits (below 86.9°F) throughout the year (Figure 32). Thermal Plume Characterization Summer 2011 Temperature profiles collected on August 25, 2011 indicated the thermal plume extended from the SQN discharge point (TRM 483.6) downstream approximately 4.1 miles to TRM 479.5 (Table 36, Figure 4). The average ambient surface water temperature (0.3 m and 1 m depths) measured at TRM 486.7 on the date of the survey was 81.86°F; the maximum temperature recorded downstream of the discharge was 86.85°F. Once discharged from diffusers located on the river bottom, the thermal plume rose to the surface and remained in the upper 1 m (3.3 ft) of 21 the water column, as evidenced by temperatures measured at TRM 481.1 and TRM 480.0 (Table 36). Autumn 2011 On August 14, 2011, the SQN thermal plume extended downstream approximately 2.6 miles to TRM 481 (Table 37, Figure 4). The average ambient surface water temperature (0.3 m and 1 m depths) measured at TRM 487.0 on the date of the survey was 77.16°F. Downstream of the discharge, the maximum water temperature measured was 81.91°F. The thermal plume remained in the upper 1 m (3.3 ft) of the water column, as evidenced by temperatures measured at TRM 483.4, TRM 482.2, and TRM 481 (Table 37). In summary, the entire biomonitoring zone downstream of SQN was contained within the thermal plume during the summer and autumn 2011 survey periods (Figure 4). The thermal plume extended further downstream during the summer monitoring period than the autumn period. The difference was attributed to several factors including releases from Watts Bar Dam upstream and Chickamauga Dam downstream of the plant, power generation at SQN, and condenser cooling water discharge. Water Quality Parameters at Fish Sampling Sites During RFAI Samples Observed values of water temperature, conductivity, dissolved oxygen, and pH are listed for each profile (LDB, mid-channel, and RDB), transect (downstream, middle, and upstream), site (TRM 482 and 490.5), and season (summer and autumn 2011) in Table 38. Summer 2011 Water temperatures at the sampling site upstream of SQN ranged from 80.44 to 83.73°F. Downstream of SQN, water temperatures ranged from 81.73 to 87.04°F. Dissolved oxygen concentrations ranged from 4.22 to 6.56 ppm at the sampling site upstream of SQN. Dissolved oxygen readings taken at the sampling site downstream of SQN ranged from 5.26 to 7.56 ppm. Conductivity values ranged from 190 to 227.5 µS at the downstream site and 193.2 to 201.3 at the upstream site. At the downstream site, pH values ranged from 7.55 to 8.5, while at the upstream site pH values ranged from 7.3 to 8.66 (Table 38). Autumn 2011 Water temperatures at the sampling site upstream of SQN ranged from 69.85 to 70.47°F. Downstream of SQN, water temperatures ranged from 70.43 to 74.89°F. Dissolved oxygen concentrations ranged from 7.10 to 7.94 ppm at the sampling site upstream of SQN. Dissolved oxygen readings taken at the sampling site downstream of SQN ranged from 6.60 to 9.69 ppm. Conductivity values ranged from 182.7 to 185.3 µS at the downstream site and 179.4 to 191.6 µS at the upstream site. At the downstream site, pH values ranged from 7.23 to 8.50, while at the upstream site pH values ranged from 7.17 to 7.6 (Table 38). 22 Literature Cited EPA (U.S. Environmental Protection Agency) and NRC (U.S. Nuclear Regulatory Commission). 1977 (draft). Interagency 316(a) Technical Guidance manual and Guide for Thermal Effects Sections of Nuclear Facilities Environmental Impact Statements. U.S. Environmental Protection Agency, Office of Water Enforcement, Permits Division, Industrial Permits Branch, Washington, DC. Etnier, D.A. & Starnes, W.C. (1993) The Fishes of Tennessee. University of Tennessee Press, Knoxville, Tennessee, 681 pp. Hickman, G. D. and T. A. McDonough. 1996. Assessing the Reservoir Fish Assemblage Index- A potential measure of reservoir quality. In: D. DeVries (Ed.) Reservoir symposium- Multidimensional approaches to reservoir fisheries management. Reservoir Committee, Southern Division, American Fisheries Society, Bethesda, MD. pp 85-97. Hubert, W. A., 1996. Passive capture techniques, entanglement gears. Pages 160-165 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society Bethesda, Maryland, USA. Jennings, M. J., L. S. Fore, and J. R. Karr. 1995. Biological monitoring of fish assemblages in the Tennessee Valley reservoirs. Regulated Rivers 11:263-274. Levene, Howard. 1960. Robust tests for equality of variances. In Ingram Olkin, Harold Hotelling, et alia. Stanford University Press. pp. 278-292. Mann, H. B.; Whitney, D. R. 1947. On a Test of Whether one of Two Random Variables is Stochastically Larger than the Other. Annals of Mathematical Statistics 18 (1): 50-60. McDonough, T.A. and G.D. Hickman. 1999. Reservoir Fish Assemblage Index development: A tool for assessing ecological health in Tennessee Valley Authority impoundments. In: Assessing the sustainability and biological integrity of water resources using fish communities. Simon, T. (Ed.) CRC Press, Boca Raton, pp 523-540. Plafkin, J.L., Barbour, M.T., Porter, K.D., Gross, S.K., and Hughes, R.M. (1989). Rapid assessment protocols for use in streams and rivers: benthic macroinvertebrates and fish. EPA/444/4-89-001, Washington DC, USA. Reynolds, J. B., 1996. Electrofishing. Pages 221-251 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society Bethesda, Maryland, USA. Shaffer, G.P., J.W. Simmons, and D.S. Baxter. 2010. Biological monitoring in the vicinity of the Sequoyah Nuclear Plant discharge, autumn 2009. Tennessee Valley Authority, Aquatic Monitoring and Management, Knoxville, TN. 76 pp. 23 Shapiro, S. S. and M. B. Wilk. 1965. An analysis of variance test for normality (complete samples). Biometrika 52 (3-4): 591-611. Simmons, J.W. 2011. Biological monitoring in the vicinity of the Sequoyah Nuclear Plant discharge, autumn 2010. Tennessee Valley Authority, Biological and Water Resources, Chattanooga, TN. 58 pp. Tennessee Valley Authority. 1988. Results of plankton studies conducted in 1986 and 1987 as part of the Operational Aquatic Monitoring Program at Sequoyah Nuclear Plant, Chickamauga Reservoir. Office of Natural Resources and Economic Development, Division of Air and Water Resources, Knoxville, Tennessee. Tennessee Valley Authority. 1989. Plankton studies at Sequoyah Nuclear Plant in 1988. River Basin Operations, Water Resources, Chattanooga, Tennessee, TVA/WR/AB-89/3.

Tennessee Valley Authority. 1990. Plankton studies at Sequoyah Nuclear Plant in 1989. River Basin Operations, Water Resources, Chattanooga, Tennessee, TVA/WR/AB-90/2. TWRC. 2006. Strategic Plan, 2006-2012. Tennessee Wildlife Resources Commission, Nashville, TN. March 2006. pp 124-125. http://tennessee.gov/twra/pdfs/StratPlan06-12.pdf Wilcoxon, F. 1945. Individual comparisons by ranking methods. Biometrics Bulletin 1 (6): 80-83 Yoder, C.O., B.J. Armitage, and E.T. Rankin. 2006. Re-evaluation of the Technical Justification for Existing Ohio River Mainstem Temperature Criteria. Midwest Biodiversity Institute, Columbus, Ohio. 24 25

Tables

26 Table 1. Shoreline Aquatic Habitat Index (SAHI) metrics and scoring criteria. Metric Scoring Criteria Score Cover Stable cover (boulders, rootwads, brush, logs, aquatic vegetation, artificial structures) in 25 to 75 % of the drawdown zone 5 Stable cover in 10 to 25 % or > 75 % of the drawdown zone 3 Stable Cover in < 10 % of the drawdown zone 1 Substrate Percent of drawdown zone with gravel substrate > 40 5 Percent of drawdown zone with gravel substrate between 10 and 40 3 Percent substrate gravel < 10 1 Erosion Little or no evidence of erosion or bank failure. Most bank surfaces stabilized by woody vegetation. 5 Areas of erosion small and infrequent. Potential for increased erosion due to less desirable vegetation cover (grasses) on > 25 % of bank surfaces. 3 Areas of erosion extensive, exposed or collapsing banks occur along > 30% of shoreline. 1 Canopy Cover Tree or shrub canopy > 60 % along adjacent bank 5 Tree or shrub canopy 30 to 60 % along adjacent bank 3 Tree or shrub canopy < 30 % along adjacent bank 1 Riparian Zone Width buffered > 18 meters 5 Width buffered between 6 and 18 meters 3 Width buffered < 6 meters 1 Habitat Habitat diversity optimum. All major habitats (logs, brush, native vegetation, boulders, gravel) present in proportions characteristic of high quality, sufficient to support all life history aspects of target species. Ready access to deeper sanctuary areas present. 5 Habitat diversity less than optimum. Most major habitats present, but proportion of one is less than desirable, reducing species diversity. No ready access to deeper sanctuary areas. 3 Habitat diversity is nearly lacking. One habitat dominates, leading to lower species diversity. No ready access to deeper sanctuary areas. 1 Gradient Drawdown zone gradient abrupt (> 1 meter per 10 meters). Less than 10 percent of shoreline with abrupt gradient due to dredging. 5 Drawdown zone gradient abrupt. (> 1 meter per 10 meters) in 10 to 40 % of the shoreline resulting from dredging. Rip-rap used to stabilize bank along > 10 % of the shoreline. 3 Drawdown zone gradient abrupt in > 40 % of the shoreline resulting from dredging. Seawalls used to stabilize bank along > 10 % of the shoreline. 1 Table 2. Expected values for upper mainstem Tennessee River reservoir transition and forebay zones. Upper Mainstem Tennessee River Transition Upper Mainstem Tennessee River Forebay Proportion Number of species Proportion Number of species Trophic Guild - Avg + - Avg + - Avg + - Avg + Benthic Invertivore < 2.4 2.4 to 4.8 > 4.8 < 2 2 to 4 > 4 < 2.2 2.2 to 4.2 > 4.2 < 2 2 to 4 > 4 Insectivore < 24.2 24.2 to 48.4 > 48.4 < 4 4 to 8 > 8 < 34.2 34.2 to 62.6 > 62.6 < 4 4 to 8 > 8 Top Carnivore < 18.9 18.9 to 37.7 > 37.7 < 4 4 to 8 > 8 < 18.8 18.8 to 33.4 > 33.4 < 4 4 to 8 > 8 Omnivore > 40.2 20.2 to 40.2 < 20.2 > 6 3 to 6 < 3 > 40.1 21.4 to 40.1 < 21.4 > 6 3 to 6 < 3 Planktivore > 41.2 20.6 to 41.2 < 20.6 0 1 > 1 > 10.4 5.2 to 10.4 < 5.2 0 1 > 1 Parasitic < 0.4 0.4 to 0.9 > 0.9 0 1 > 1 < 0.4 0.4 to 0.8 > 0.8 0 1 > 1 Herbivore --- --- --- --- --- --- --- --- --- --- --- --- *Values calculated from data collected from 1993 to 2010 from 750 electrofishing runs and 500 overnight experimental gill net sets in upper mainstem Tennessee River reservoir transition areas and from 900 electrofishing runs and 600 overnight experimental gill net sets in forebay areas of upper mainstem Tennessee River reservoirs. This trisection is intended to show less than expected (-), expected or average (Avg), and above expected or average (+) values for trophic level proportions and species occurring within each reservoir zone in upper mainstem Tennessee River reservoirs..27 Table 3. Average trophic guild proportions and average number of fish species, bound by confidence intervals (95%), expected in upper mainstem Tennessee River reservoir transition and forebay zones and proportions and numbers of species observed during summer and autumn 2011. Transition Zones Summer 2011 (Upstream) Autumn 2011 (Upstream) Forebay Zones Summer 2011 (Downstream) Autumn 2011 (Downstream) Trophic Guild Average Proportion (%) Average Number of Species Proportion (%) Number of Species Proportion (%) Number of Species Average Proportion (%) Average Number of Species Proportion (%) Number of Species Proportion (%) Number of Species Benthic Invertivore 3.1 + 0.2 3.7 + 0.2 2.6 4 1.3 3 2.3 + 0.4 3.3 + 0.3 1.7 3 0.8 3 Insectivore 44.5 + 2.2 9.2 + 0.5 52.2 10 45.6 8 50.4 + 5.7 8.7 + 0.5 52.0 10 48.3 8 Top Carnivore 18.2 + 0.9 10.2 + 0.5 8.8 10 8.2 11 19.0 + 2.7 9.9 + 0.3 11.0 10 5.2 9 Omnivore 29.5 + 1.5 6.4 + 0.3 36.3 7 33.3 6 22.4 + 3.5 6.1 + 0.3 35.2 7 29.7 6 Planktivore 5.6 + 0.3 1.1 + 0.1 0.1 1 1.1 1 1.8 + 0.9 1.0 + 0.1 0.1 1 16.1 1 Parasitic 0.04 + 0.02 1.0 + 0.1 ---- ---- ---- ---- 0.05 + 0.05 0.1 + 0.08 ---- ---- ---- ---- Herbivore 0.01 + 0.004 1.0 + 0.1 ---- ---- 0.1 1 ---- ---- ---- ---- ---- ---- *Expected values were calculated using data collected from 1993 to 2010 from 750 electrofishing runs and 500 overnight experimental gill net sets in upper mainstem Tennessee River reservoir transition areas and from 900 electrofishing runs and 600 overnight experimental gill net sets in forebay areas of upper mainstem Tennessee River reservoirs.28 Table 4. RFAI scoring criteria (2002) for fish community samples in forebay, transition, and inflow sections of upper mainstream Tennessee River reservoirs. Upper mainstream reservoirs include Nickajack, Chickamauga, Watts Bar, Fort Loudoun, Melton Hill, and Tellico. Scoring Criteria Forebay Transition Inflow Metric Gear 1 3 5 1 3 5 1 3 5 1. Total species Combined <14 14-27 >27 <15 15-29 >29 <14 14-27 >27 2. Total Centrarchid species Combined <2 2-4 >4 <2 2-4 >4 <3 3-4 >4 3. Total benthic invertivores Combined <4 4-7 >7 <4 4-7 >7 <3 3-6 >6 4. Total intolerant species Combined <2 2-4 >4 <2 2-4 >4 <2 2-4 >4 5. Percent tolerant individuals Electrofishing >62% 31-62%<31% >62% 31-62%<31% >58% 29-58%<29% Gill netting >28% 14-28%<14% >32% 16-32%<16% 6. Percent dominance by 1 species Electrofishing >50% 25-50%<25% >40% 20-40%<20% >46% 23-46%<23% Gill netting >29% 15-29%<15% >28% 14-28%<14% 7. Percent non-indigenous species Electrofishing >4% 2-4% <2% >6% 3-6% <3% >17% 8-17% <8% Gill netting >16% 8-16% <8% >9% 5-9% <5% 8. Total top carnivore species Combined <4 4-7 >7 <4 4-7 >7 <3 3-6 >6 9. Percent top carnivores Electrofishing <5% 5-10% >10% <6% 6-11% >11% <11% 11-22%>22% Gill netting <25% 25-50%>50% <26% 26-52%>52% 10. Percent omnivores Electrofishing >49% 24-49%<24% >44% 22-44%<22% >55% 27-55%<27% Gill netting >34% 17-34%<17% >46% 23-46%<23% 11. Average number per run Electrofishing <121 121-241>241 <105 105-210>210 <51 51-102 >102 Gill netting <12 12-24 >24 <12 12-24 >24 12. Percent anomalies Electrofishing >5% 2-5% <2% >5% 2-5% <2% >5% 2-5% <2% Gill netting >5% 2-5% <2% >5% 2-5% <2% 29 Table 5. Scoring criteria for benthic macroinvertebrate community samples (lab-processed) for forebay, transition, and inflow sections of mainstream Tennessee River reservoirs. (TRM 481.3 and TRM 483.4-Forbay, TRM 488.0 and TRM 490.5-Transition) scoring criteria were used for sites upstream and downstream of SQN. Benthic Community Forebay Transition Inflow Metrics 1 3 5 1 3 5 1 3 5 Average number of taxa < 2.8 2.8-5.5 > 5.5 < 3.3 3.3-6.6 > 6.6 < 4.2 4.2-8.3 > 8.3 Proportion of samples with long-lived organisms

< 0.6 0.6-0.8 > 0.8 < 0.6 0.6-0.9 > 0.9 < 0.6 0.6-0.8 > 0.8 Average number of EPT (Ephemeroptera, Plecoptera, Trichoptera)

< 0.6 0.6-0.9 > 0.9 < 0.6 0.6-1.4 > 1.4 < 0.9 0.9-1.9 > 1.9 Average proportion of oligochaete individuals

> 41.9 41.9-21.0 < 21.0 > 21.9 21.9-11.0 < 11.0 > 23.9 23.9-12.0 < 12.0 Average proportion of total abundance comprised by the two most abundant taxa > 90.3 90.3-81.7 < 81.7 > 87.9 87.9-77.8 < 77.8 > 86.2 86.2-73.1 < 73.1 Average density excluding chironomids and oligochaetes < 125.0 125.0-249.9 > 249.9 < 305.0 305.0-609.9 > 609.9 < 400.0 400.0-799.9 > 799.9 Zero-samples - proportion of samples containing no organisms > 0 --- 0 > 0 --- 0 > 0 --- 0 30 31 Table 6. SAHI scores for 16 shoreline habitat assessments conducted within the Upstream RFAI sampling area of SQN on Chickamauga Reservoir, autumn 2009. 1(LD) 2(LD) 3(LD) 4(LD) 5(LD) 6(LD) 7(LD) 8(LD) Avg. Latitude 35.26755 35.27312 35.27784 35.28179 35.28669 35.29674 35.20021 35.3037 Longitude -85.09749 -85.09602 -85.09093 -85.08571 -85.0741 -85.06678 -85.06367 -85.06049 Aquatic Macrophytes 0% 0% 0% 0% 0% 0% 0% 0% 0% SAHI Variables Cover 1 1 5 1 5 1 1 3 2 Substrate 5 1 1 1 3 5 3 5 3 Erosion 1 5 1 5 5 3 1 3 3 Canopy Cover 5 5 5 5 1 5 5 5 5 Riparian Zone 5 5 5 5 1 5 5 5 5 Habitat 1 1 3 1 3 1 1 3 2 Slope 1 1 1 1 3 3 3 3 2 Total 19 19 21 19 21 23 19 27 22 Rating Fair Fair Fair Fair Fair Fair Fair Good Fair 1(RD) 2(RD) 3(RD) 4(RD) 5(RD) 6(RD) 7(RD) 8(RD) Avg. Latitude 35.26823 35.27665 35.28347 35.28747 35.29329 35.30095 35.30458 35.3092 Longitude -85.108 -85.10484 -85.09809 -85.09035 -85.08268 -85.07718 -85.07455 -85.07194 Aquatic Macrophytes 0% 0% 0% 0% 0% 0% 0% 0% 0% SAHI Variables Cover 3 1 5 5 3 3 5 1 3 Substrate 5 5 5 5 1 5 1 1 4 Erosion 1 1 5 5 5 5 5 3 4 Canopy Cover 5 5 1 3 5 3 3 1 3 Riparian Zone 5 5 1 1 5 1 1 1 3 Habitat 1 3 3 3 1 3 3 1 2 Slope 1 1 1 1 1 3 1 3 2 Total 21 21 21 23 21 23 19 11 21 Rating Fair Fair Fair Fair Fair Fair Fair Poor Fair *Scores are shown for eight shoreline sections on the left descending bank (LD) and eight shoreline sections along the right descending bank (RD). Scoring criteria: poor (7-16); fair (17-26); and good (27-35).

32 Table 7. SAHI Scores for 16 Shoreline Habitat Assessments Conducted within the Downstream RFAI Sampling Area of SQN on Chickamauga Reservoir, Autumn 2009. 1(LD) 2(LD) 3(LD) 4(LD) 5(LD) 6(LD) 7(LD) 8(LD) Avg. Latitude 35.19455 35.20021 35.20443 35.20584 35.20617 35.2061 35.20865 35.21104 Longitude -85.11967 -85.11858 -85.11671 -85.11346 -85.10754 -85.10212 -85.09711 -85.09188 Aquatic Macrophytes 0% 0% 15% 0% 0% 10% 0% 0% 2% SAHI Variables Cover 5 5 5 5 3 1 1 3 4 Substrate 1 1 1 3 1 1 1 1 1 Erosion 3 5 3 3 3 1 3 5 3 Canopy Cover 5 3 5 5 5 5 1 1 4 Riparian Zone 5 3 5 5 5 5 1 3 4 Habitat 3 3 3 3 1 1 3 1 2 Slope 3 5 5 3 5 5 1 1 4 Total 25 25 27 27 23 19 11 15 22 Rating Fair Fair Good Good Fair Fair Poor Poor Fair 1(RD) 2(RD) 3(RD) 4(RD) 5(RD) 6(RD) 7(RD) 8(RD) Avg. Latitude 35.19718 35.20069 35.20722 35.20967 35.21449 35.21521 35.21565 35.2159 Longitude -85.12923 -85.12331 -85.12156 -85.11884 -85.1115 -85.10953 -85.10047 -85.09368 Aquatic Macrophytes 0% 0% 0% 0% 10% 5% 25% 0% 5% SAHI Variables Cover 3 5 5 3 1 3 5 3 4 Substrate 3 1 3 3 1 1 1 1 2 Erosion 5 5 5 5 3 3 1 5 4 Canopy Cover 5 5 5 1 1 1 5 1 3 Riparian Zone 5 5 5 1 1 1 3 5 3 Habitat 1 3 3 3 1 1 3 1 2 Slope 3 1 3 1 5 5 5 5 4 Total 25 25 29 17 13 15 23 21 22 Rating Fair Fair Good Fair Poor Poor Fair Fair Fair *Scores are Shown for Eight Shoreline Sections on the Left Descending Bank (LD) and Eight Shoreline Sections Along the Right Descending Bank (RD). Scoring Criteria: Poor (7-16); Fair (17-26); and good (27-35).

Table 8. Substrate percentages and average water depth (ft) per transect upstream (8 transects) and downstream (8 transects) of SQN.  % Substrate per transect downstream of SQN 1 2 3 4 5 6 7 8 AVG Mollusk shell 15.5 32.0 20.5 26.0 24.5 22.5 26.5 52.9 27.6 Silt 37.5 12.0 11.0 13.0 23.5 36.0 19.5 7.0 19.9 Clay 14.0 16.0 9.0 30.0 8.0 29.5 6.0 17.0 16.4 Sand 19.5 14.0 22.0 6.0 12.0 3.5 28.5 2.5 13.5 Bedrock 10.0 9.0 18.0 20. 20.0 0 10.0 15.0 12.8 Detritus 2.5 4.5 3.5 3.5 3.0 5.0 3.0 4.6 3.7 Gravel 0 3.0 7.0 1.0 8.0 3.5 3.5 0.5 3.0 Cobble 1.0 9.5 9.0 0.5 1.0 0 3.0 0.5 3.1 Avg. depth (ft) 27.1 39.7 32.6 33.2 27 29.8 35.1 44.7 33.7 Actual depth range: 7.4 to 78.5 ft  % Substrate per transect upstream of SQN 1 2 3 4 5 6 7 8 AVG Silt 30.5 43.0 56.5 22.0 45.5 71.0 63.5 77.5 51.2 Mollusk shell 25.0 19.5 15.5 33.5 20.0 10.0 15.5 8.0 18.4 Bedrock 10.0 20.0 0 20.0 20.0 0 0 0 8.8 Detritus 7.0 7.0 8.5 7.5 2.5 10.5 9.0 8.0 7.5 Clay 14.0 0 0 5 7.0 8.5 8.0 6.5 6.1 Cobble 4.0 5.0 10.0 0 2.5 0 4.0 0 3.2 Sand 7.5 5.5 7.5 4.5 0.5 0 0 0 3.1 Gravel 2.0 0 2.0 7.5 2.0 0 0 0 1.7 Avg. depth (ft) 33 30.1 34.9 33.6 26.2 31.8 32.2 26.1 31.0 Actual depth range: 6.4 to 55.2 ft 33 34 Table 9. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 482) and Upstream (TRM 490.5) of Sequoyah Nuclear Plant Summer 2011. Summer 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net)Obs Score Obs Score A. Species richness and composition 1. Number of indigenous species (Tables 11 and 12) Combined 28 5 29 3 2. Number of centrarchid species (less Micropterus) Combined 8 Black crappie Bluegill Green sunfish Longear sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 5 8 Black crappie Bluegill Green sunfish Longear sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 5 3. Number of benthic invertivore species Combined 3 Freshwater drum Logperch Spotted sucker 1 4 Freshwater drum Logperch River redhorse Spotted sucker 3 4. Number of intolerant species Combined 5 Brook silverside Longear sunfish Skipjack herring Smallmouth bass Spotted sucker 5 6 Brook silverside Longear sunfish River redhorse Skipjack herring Smallmouth bass Spotted sucker 5 35 Table 9. (Continued) Summer 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net)Obs Score Obs Score 5. Percent tolerant individuals Electrofishing 85.7% Bluegill 49.1% Bluntnose minnow 1.6% Common carp 0.2% Gizzard shad 26.9% Golden shiner 1.6% Green sunfish 0.1% Largemouth bass 3.8% Redbreast sunfish 1.6% Spotfin shiner 0.7% 0.5 79.8% Bluegill 40.7% Bluntnose minnow 5.3% Common carp 0.2% Gizzard shad 28.2% Golden shiner 1.1% Green sunfish 0.3% Largemouth bass 1.7% Redbreast sunfish 1.4% Spotfin shiner 1.0% 0.5 Gill Netting 55.1% Bluegill 0.7% Common carp 0.7% Gizzard shad 52.2% White crappie 1.4% 0.5 43.9% Bluegill 0.8% Gizzard shad 37.9% Golden shiner 3.8% Largemouth bass 0.8% White crappie 0.8% 0.5 6. Percent dominance by one species Electrofishing 49.1% Bluegill 1.5 40.7% Bluegill 0.5 Gill Netting 52.2% Gizzard shad 0.5 37.9% Gizzard shad 0.5 7. Percent non-indigenous species Electrofishing 2.9% Common carp 0.3% Mississippi silverside 2.5% Yellow perch 0.1% 1.5 5.2% Common carp 0.1% Mississippi silverside 4.8% Yellow perch 0.3% 1.5 Gill Netting 0.7% Common carp 2.5 0% 2.5 36 Table 9. (Continued) Summer 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net)Obs Score Obs Score 8. Number of top carnivore species

Combined 10 Black crappie Flathead catfish Largemouth bass Skipjack herring Smallmouth bass Spotted bass Spotted gar White bass White crappie Yellow bass 5 10 Black crappie Flathead catfish Largemouth bass Sauger Skipjack herring Smallmouth bass Spotted bass Spotted gar White crappie Yellow bass 5 B. Trophic composition 9. Percent top carnivores Electrofishing 8.2% Black crappie 1.0% Largemouth bass 3.0% Smallmouth bass 0.1% Spotted bass 0.8% Spotted gar 2.2% White bass 0.1% Yellow bass 0.2% 1.5 5.3% Flathead catfish 0.8% Largemouth bass 1.7% Smallmouth bass 0.2% Spotted bass 1.1% Spotted gar 1.5% 0.5 Gill Netting 29.0% Black crappie 10.1% Flathead catfish 1.4% Skipjack herring 1.4% Spotted bass 7.2% Spotted gar 1.4% White bass 0.7% White crappie 1.4% Yellow bass 5.1% 1.5 42.4% Black crappie 16.7% Flathead catfish 1.5% Largemouth bass 0.8% Sauger 0.8% Skipjack herring 15.2% Spotted bass 2.3% White crappie 0.8% Yellow bass 4.5% 1.5 37 Table 9. (Continued) Summer 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net)Obs Score Obs Score 10. Percent omnivores Electrofishing 31.2% Bluntnose minnow 1.6% Channel catfish 0.7% Common carp 0.2% Gizzard shad 26.9% Golden shiner 1.6% Smallmouth buffalo 0.1% 2.5 35.1% Bluntnose minnow 5.3% Channel catfish 0.2% Common carp 0.2% Gizzard shad 28.2% Golden shiner 1.1% Smallmouth buffalo 0.2% 1.5 Gill Netting 61.6% Blue catfish 5.8% Channel catfish 1.4% Common carp 0.7% Gizzard shad 52.2% Smallmouth buffalo 1.4% 0.5 47.7% Blue catfish 4.5% Channel catfish 1.5% Gizzard shad 37.9% Golden shiner 3.8% 0.5 C. Fish abundance and health 11. Average number per run Electrofishing 60.7 0.5 82.4 0.5 Gill Netting 13.8 1.5 13.2 1.5 12. Percent anomalies Electrofishing 1.2% 2.5 0.6% 2.5 Gill Netting 0% 2.5 0% 2.5 Overall RFAI Score 41 Good 38 Fair 38 Table 10. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 482) and Upstream (TRM 490.5) of (Sequoyah nuclear) Autumn 2011. Autumn 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net) Obs Score Obs Score A. Species richness and composition 1. Number of indigenous species (Tables 13 and 14) Combined 25 3 27 3 2. Number of centrarchid species (less Micropterus) Combined 7 Black crappie Bluegill Green sunfish Longear sunfish Redbreast sunfish Redear sunfish Warmouth 5 7 Black crappie Bluegill Green sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 5 3. Number of benthic invertivore species Combined 3 Freshwater drum Golden redhorse Spotted sucker 1 3 Freshwater drum Logperch Spotted sucker 1 4. Number of intolerant species Combined 4 Longear sunfish Skipjack herring Smallmouth bass Spotted sucker 3 3 Skipjack herring Smallmouth bass Spotted sucker 3 5. Percent tolerant individuals Electrofishing 42.6% Bluegill 12.3% Bluntnose minnow 0.5% Common carp 0.% Gizzard shad 26.1% Golden shiner 0.3% Green sunfish 0.1% Largemouth bass 1.6% Redbreast sunfish 0.9% Spotfin shiner 0.5% 1.5 80.8% Bluegill 43.0% Bluntnose minnow 0.1% Common carp 0.1% Gizzard shad 30.8% Golden shiner 0.2% Green sunfish 0.1% Largemouth bass 1.7% Redbreast sunfish 4.7% Spotfin shiner 0.2% 0.5 39 Table 10 (continued). Autumn 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net) Obs Score Obs Score Gill Netting 64.8% Bluegill 0.8% Gizzard shad 63.1% Largemouth bass 0.8% 0.5 42.4% Bluegill 0.7% Gizzard shad 39.6% Golden shiner 0.7% White crappie 1.4% 0.5 6. Percent dominance by one species Electrofishing 35.1% Mississippi silverside 1.5 43.0% Bluegill 0.5 Gill Netting 63.1% Gizzard shad 0.5 39.6% Gizzard shad 0.5 7. Percent non-indigenous species Electrofishing 33.8% Common carp 0.3% Mississippi silverside 33.5% 0.5 6.9% Common carp 0.1% Mississippi silverside 6.3% Yellow perch 0.1% 0.5 Gill Netting 0% 2.5 0% 2.5 40 Table 10. (Continued)Autumn 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net) Obs Score Obs Score 8. Number of top carnivore species Combined 9 Black crappie Flathead catfish Largemouth bass Skipjack herring Smallmouth bass Spotted bass Spotted gar White bass Yellow bass 5 11 Black crappie Flathead catfish Largemouth bass Skipjack herring Smallmouth bass Spotted bass Spotted gar Walleye White bass White crappie Yellow bass 5 B. Trophic composition 9. Percent top carnivores Electrofishing 4.5% Black crappie 1.9% Flathead catfish 0.01% Largemouth bass 1.6% Smallmouth bass 0.01% Spotted bass 0.4% Spotted gar 0.6% 0.5 6.2% Black crappie 1.4% Flathead catfish 0.5% Largemouth bass 1.7% Smallmouth bass 0.9% Spotted bass 1.4% Spotted gar 0.1% White bass 0.1% Yellow bass 0.2% 1.5 Gill Netting 19.7% Black crappie 7.4% Flathead catfish 2.5% Largemouth bass 0.8% Skipjack herring 1.6% Smallmouth bass 0.8% Spotted bass 4.1% White bass 0.8% Yellow bass 1.6% Black crappie 7.4% 0.5 34.5% Black crappie 12.2% Flathead catfish 0.7% Skipjack herring 8.6% Spotted bass 6.5% Walleye 0.7% White bass 1.4% White crappie 1.4% Yellow bass 2.9% 1.5 41 Table 10. (Continued) Autumn 2011 Gear TRM 482 TRM 490.5 Metric (Electrofishing/Gill Net) Obs Score Obs Score 10. Percent omnivores Electrofishing 27.5% Blue catfish 0.01% Bluntnose minnow 0.5% Channel catfish 0.2% Common carp 0.3% Gizzard shad 26.1% Golden shiner 0.3% 1.5 31.9% Blue catfish 0.1% Bluntnose minnow 0.1% Channel catfish 0.7% Common carp 0.1% Gizzard shad 30.8% Golden shiner 0.2% Blue catfish 0.1% 1.5 Gill Netting 76.2% Blue catfish 9.8% Channel catfish 3.3% Gizzard shad 63.1% 0.5 51.1% Blue catfish 5.8% Channel catfish 5.0% Gizzard shad 39.6% Golden shiner 0.7% 0.5 C. Fish abundance and health 11. Average number per run Electrofishing 174.2 1.5 122.4 1.5 Gill Netting 12.2 1.5 13.9 1.5 12. Percent anomalies Electrofishing 0.6 2.5 0.3 2.5 Gill Netting 0 2.5 0 2.5 Overall RFAI Score 35 35 Fair Fair 42 Table 11. Summer 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Downstream (TRM 482.0) of Sequoyah Nuclear Plant Discharge, Summer 2011. Common Name Scientific name Trophic level Indigenous species ToleranceThermally Sensitive Species Commer-cially Valuable Species Recrea- tionally ValuableSpecies EF Catch Rate Per Run EF CatchRate PerHour Total fish EF Gill Netting Catch Rate PerNet Night Total Gill net fish Total fish Combined Percent Composition Gizzard shad Dorosoma cepedianum OM X TOL . X X 16.33 57.38 245 7.20 72 317 30.2% Common carp Cyprinus carpio OM . TOL . X . 0.13 0.47 2 0.10 1 3 0.3% Golden shiner Notemigonus crysoleucas OM X TOL . X . 1.00 3.51 15 . . 15 1.4% Spotfin shiner Cyprinella spiloptera IN X TOL . . . 0.40 1.41 6 . . 6 0.6% Bluntnose minnow Pimephales notatus OM X TOL . . X 1.00 3.51 15 . . 15 1.4% Redbreast sunfish Lepomis auritus IN X TOL . . X 1.00 3.51 15 . . 15 1.4% Green sunfish Lepomis cyanellus IN X TOL . . X 0.07 0.23 1 . . 1 0.1% Bluegill Lepomis macrochirus IN X TOL . . X 29.80 104.68 447 0.10 1 448 42.7% Largemouth bass Micropterus salmoides TC X TOL . . X 2.33 8.20 35 . . 35 3.3% White crappie Pomoxis annularis TC X TOL . . X . . . 0.20 2 2 0.2% Skipjack herring Alosa chrysochloris TC X INT . X X . . . 0.20 2 2 0.2% Spotted sucker Minytrema melanops BI X INT X X . 0.47 1.64 7 0.20 2 9 0.9% Longear sunfish Lepomis megalotis IN X INT . . X 0.13 0.47 2 0.10 1 3 0.3% Smallmouth bass Micropterus dolomieu TC X INT . . X 0.07 0.23 1 . . 1 0.1% Brook silverside Labidesthes sicculus IN X INT . X X 0.07 0.23 1 . . 1 0.1% Spotted gar Lepisosteus oculatus TC X . . X . 1.33 4.68 20 0.20 2 22 2.1% Threadfin shad Dorosoma petenense PK X . . X X 0.13 0.47 2 . . 2 0.2% Smallmouth buffalo Ictiobus bubalus OM X . . X X 0.07 0.23 1 0.20 2 3 0.3% Blue catfish Ictalurus furcatus OM X . . X X . . . 0.80 8 8 0.8% Channel catfish Ictalurus punctatus OM X . . X X 0.40 1.41 6 0.20 2 8 0.8% Flathead catfish Pylodictis olivaris TC X . . X X . . . 0.20 2 2 0.2% White bass Morone chrysops TC X . . . X 0.07 0.23 1 0.10 1 2 0.2% Yellow bass Morone mississippiensis TC X . . . X 0.13 0.47 2 0.70 7 9 0.9% Warmouth Lepomis gulosus IN X . . . X 0.07 0.23 1 . . 1 0.1% Redear sunfish Lepomis microlophus IN X . . . X 2.53 8.90 38 0.50 5 43 4.1% Spotted bass Micropterus punctulatus TC X . . . X 0.47 1.64 7 1.00 10 17 1.6% Black crappie Pomoxis nigromaculatus TC X . . . X 0.60 2.11 9 1.40 14 23 2.2% Yellow perch Perca flavescens IN . . . . X 0.07 0.23 1 . . 1 0.1% Logperch Percina caprodes BI X . X . X 0.33 1.17 5 . . 5 0.5% Freshwater drum Aplodinotus grunniens BI X . . X X . . . 0.40 4 4 0.4% Mississippi silverside Menidia audens IN . . . X . 1.73 6.09 26 . . 26 2.5% Total 28 2 14 25 60.73 213.33 911 13.80 138 1,049 100% Number Samples 15 10 Species Collected 26 18 *All species listed are Resident Important Species (RIS). No federally threatened or endangered species were collected. Trophic: benthic invertivore (BI), insectivore (IN), omnivore (OM), planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT).

43 Table 12. Summer 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 490.5) of Sequoyah Nuclear Plant Discharge, Summer 2011. Common Name Scientific name Trophic level Indigenous species ToleranceThermally Sensitive Species Commer-cially Valuable Species Recrea- tionally ValuableSpecies EF Catch Rate Per Run EF CatchRate PerHour Total fish EF Gill Netting Catch Rate PerNet Night Total Gill net fish Total fish Combined Percent Composition Gizzard shad Dorosoma cepedianum OM XTOL.XX23.27 81.543495.005039929.2% Common carp Cyprinus carpio OM . TOL . X . 0.13 0.47 2 . . 2 0.1% Golden shiner Notemigonus crysoleucas OM X TOL . X . 0.87 3.04 13 0.50 5 18 1.3% Spotfin shiner Cyprinella spiloptera IN X TOL . . . 0.80 2.80 12 . . 12 0.9% Bluntnose minnow Pimephales notatus OM X TOL . . X 4.33 15.19 65 . . 65 4.8% Redbreast sunfish Lepomis auritus IN X TOL . . X 1.13 3.97 17 . . 17 1.2% Green sunfish Lepomis cyanellus IN X TOL . . X 0.27 0.93 4 . . 4 0.3% Bluegill Lepomis macrochirus IN X TOL . . X 33.53 117.52 503 0.10 1 504 36.8% Largemouth bass Micropterus salmoides TC X TOL . . X 1.40 4.91 21 0.10 1 22 1.6% White crappie Pomoxis annularis TC X TOL . . X . . . 0.10 1 1 0.1% Skipjack herring Alosa chrysochloris TC X INT . X X . . . 2.00 20 20 1.5% Spotted sucker Minytrema melanops BI X INT X X . 0.53 1.87 8 0.10 1 9 0.7% River redhorse Moxostoma carinatum BI X INT . . . 0.07 0.23 1 . . 1 0.1% Longear sunfish Lepomis megalotis IN X INT . . X 0.53 1.87 8 . . 8 0.6% Smallmouth bass Micropterus dolomieu TC X INT . . X 0.13 0.47 2 . . 2 0.1% Brook silverside Labidesthes sicculus IN X INT . X . 0.13 0.47 2 . . 2 0.1% Spotted gar Lepisosteus oculatus TC X . . X . 1.27 4.44 19 . . 19 1.4% Threadfin shad Dorosoma petenense PK X . . X X 0.07 0.23 1 . . 1 0.1% Smallmouth buffalo Ictiobus bubalus OM X . . X X 0.13 0.47 2 . . 2 0.1% Blue catfish Ictalurus furcatus OM X . . X X . . . 0.60 6 6 0.4% Channel catfish Ictalurus punctatus OM X . . X X 0.20 0.70 3 0.20 2 5 0.4% Flathead catfish Pylodictis olivaris TC X . . X X 0.67 2.34 10 0.20 2 12 0.9% Yellow bass Morone mississippiensis TC X . . . X . . . 0.60 6 6 0.4% Warmouth Lepomis gulosus IN X . . . X 0.13 0.47 2 . . 2 0.1% Redear sunfish Lepomis microlophus IN X . . . X 5.93 20.79 89 0.70 7 96 7.0% Spotted bass Micropterus punctulatus TC X . . . X 0.87 3.04 13 0.30 3 16 1.2% Black crappie Pomoxis nigromaculatus TC X . . . X . . . 2.20 22 22 1.6% Yellow perch Perca flavescens IN . . . . X 0.27 0.93 4 . . 4 0.3% Logperch Percina caprodes BI X . X . X 1.27 4.44 19 . . 19 1.4% Sauger Sander canadense TC X . . . X . . . 0.10 1 1 0.1% Freshwater drum Aplodinotus grunniens BI X . . X X 0.13 0.47 2 0.40 4 6 0.4% Mississippi silverside Menidia audens IN . . . X . 4.33 15.19 65 . . 65 4.8% Total 292142482.39 288.791,23613.201321,368100% Number Samples 15 10 Species Collected 26 16 *All species listed are Resident Important Species (RIS). No federally threatened or endangered species were collected. Trophic: benthic invertivore (BI), insectivore (IN), omnivore (OM), planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT).

44 Table 13. Autumn 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Downstream (TRM 482.0) of Sequoyah Nuclear Plant Discharge, Autumn 2011. Common Name Scientific name Trophic level Indigenous species Tolerance Thermally Sensitive Species Commer-cially Valuable Species Recrea- tionally ValuableSpecies EF Catch Rate Per Run EF CatchRate PerHour Total fish EF Gill Netting Catch Rate PerNet Night Total Gill net fish Total fish Combined Percent Composition Gizzard shad Dorosoma cepedianum OM X TOL . X X 45.53 212.11 683 7.70 77 760 27.8% Common carp Cyprinus carpio OM . TOL . X . 0.47 2.17 7 . . 7 0.3% Golden shiner Notemigonus crysoleucas OM X TOL . X . 0.60 2.80 9 . . 9 0.3% Spotfin shiner Cyprinella spiloptera IN X TOL . . . 0.80 3.73 12 . . 12 0.4% Bluntnose minnow Pimephales notatus OM X TOL . . X 0.93 4.35 14 . . 14 0.5% Redbreast sunfish Lepomis auritus IN X TOL . . X 1.60 7.45 24 . . 24 0.9% Green sunfish Lepomis cyanellus IN X TOL . . X 0.07 0.31 1 . . 1 0.0% Bluegill Lepomis macrochirus IN X TOL . . X 21.47 100.00 322 0.10 1 323 11.8% Largemouth bass Micropterus salmoides TC X TOL . . X 2.73 12.73 41 0.10 1 42 1.5% Skipjack herring Alosa chrysochloris TC X INT . X X . . . 0.20 2 2 0.1% Spotted sucker Minytrema melanops BI X INT X X . 0.73 3.42 11 0.10 1 12 0.4% Longear sunfish Lepomis megalotis IN X INT . . X 0.13 0.62 2 . . 2 0.1% Smallmouth bass Micropterus dolomieu TC X INT . . X 0.07 0.31 1 0.10 1 2 0.1% Spotted gar Lepisosteus oculatus TC X . . X . 1.00 4.66 15 . . 15 0.5% Threadfin shad Dorosoma petenense PK X . . X . 29.27 136.34 439 . . 439 16.1% Golden redhorse Moxostoma erythrurum BI X . . X . . . . 0.10 1 1 0.0% Blue catfish Ictalurus furcatus OM X . . X X 0.07 0.31 1 1.20 12 13 0.5% Channel catfish Ictalurus punctatus OM X . . X X 0.33 1.55 5 0.40 4 9 0.3% Flathead catfish Pylodictis olivaris TC X . . X X 0.07 0.31 1 0.30 3 4 0.1% White bass Morone chrysops TC X . . . X . . . 0.10 1 1 0.0% Yellow bass Morone mississippiensis TC X . . . X . . . 0.20 2 2 0.1% Warmouth Lepomis gulosus IN X . . . X 0.47 2.17 7 . . 7 0.3% Redear sunfish Lepomis microlophus IN X . . . X 2.27 10.56 34 0.10 1 35 1.3% Spotted bass Micropterus punctulatus TC X . . . X 0.73 3.42 11 0.50 5 16 0.6% Black crappie Pomoxis nigromaculatus TC X . . . X 3.27 15.22 49 0.90 9 58 2.1% Freshwater drum Aplodinotus grunniens BI X . . X X 0.47 2.17 7 0.10 1 8 0.3% Mississippi silverside Menidia audens IN . . . X . 61.13 284.78 917 . . 917 33.5% Total 25 1 13 19 174.21 811.49 2,613 12.20 122 2,735 100% Number Samples 15 10 Species Collected 23 16 *All species listed are Resident Important Species (RIS). No federally threatened or endangered species were collected. Trophic: benthic invertivore (BI), insectivore (IN), omnivore (OM), planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT).

45 Table 14. Autumn 2011 Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 490.5) of Sequoyah Nuclear Plant Discharge, Autumn 2011. Common Name Scientific name Trophic level Indigenous species Tolerance Thermally Sensitive Species Commer-cially Valuable Species Recrea- tionally ValuableSpecies EF Catch Rate Per Run EF CatchRate PerHour Total fish EF Gill Netting Catch Rate PerNet Night Total Gill net fish Total fish Combined Percent Composition Gizzard shad Dorosoma cepedianum OM X TOL . X X 37.73 164.53 566 5.50 55 621 31.4% Common carp Cyprinus carpio OM . TOL . X . 0.07 0.29 1 . . 1 0.1% Golden shiner Notemigonus crysoleucas OM X TOL . X . 0.27 1.16 4 0.10 1 5 0.3% Spotfin shiner Cyprinella spiloptera IN X TOL . . . 0.27 1.16 4 . . 4 0.2% Bluntnose minnow Pimephales notatus OM X TOL . . X 0.13 0.58 2 . . 2 0.1% Redbreast sunfish Lepomis auritus IN X TOL . . X 5.73 25.00 86 . . 86 4.4% Green sunfish Lepomis cyanellus IN X TOL . . X 0.07 0.29 1 . . 1 0.1% Bluegill Lepomis macrochirus IN X TOL . . X 52.60 229.36 789 0.10 1 790 40.0% Largemouth bass Micropterus salmoides TC X TOL . . X 2.07 9.01 31 . . 31 1.6% White crappie Pomoxis annularis TC X TOL . . X . . . 0.20 2 2 0.1% Skipjack herring Alosa chrysochloris TC X INT . X X . . . 1.20 12 12 0.6% Smallmouth bass Micropterus dolomieu TC X INT . . X 1.07 4.65 16 . . 16 0.8% Spotted sucker Minytrema melanops BI X INT X . . 0.40 1.74 6 0.40 4 10 0.5% Spotted gar Lepisosteus oculatus TC X . . X X 0.13 0.58 2 . . 2 0.1% Threadfin shad Dorosoma petenense PK X . . X . 1.47 6.40 22 . . 22 1.1% Largescale stoneroller Campostoma oligolepis HB X . . . X 0.93 4.07 14 . . 14 0.7% Blue catfish Ictalurus furcatus OM X . . X X 0.07 0.29 1 0.80 8 9 0.5% Channel catfish Ictalurus punctatus OM X . . X X 0.80 3.49 12 0.70 7 19 1.0% Flathead catfish Pylodictis olivaris TC X . . X X 0.60 2.62 9 0.10 1 10 0.5% White bass Morone chrysops TC X . . . X 0.07 0.29 1 0.20 2 3 0.2% Yellow bass Morone mississippiensis TC X . . . X 0.20 0.87 3 0.40 4 7 0.4% Warmouth Lepomis gulosus IN X . . . X 0.67 2.91 10 . . 10 0.5% Redear sunfish Lepomis microlophus IN X . . . X 4.27 18.60 64 1.50 15 79 4.0% Spotted bass Micropterus punctulatus TC X . . . X 1.67 7.27 25 0.90 9 34 1.7% Black crappie Pomoxis nigromaculatus TC X . . . X 1.73 7.56 26 1.70 17 43 2.2% Yellow perch Perca flavescens IN . . . . X 0.13 0.58 2 . . 2 0.1% Logperch Percina caprodes BI X . X . X 0.07 0.29 1 . . 1 0.1% Walleye Sander vitreum TC X . . . X . . . 0.10 1 1 0.1% Freshwater drum Aplodinotus grunniens BI X . . X X 0.93 4.07 14 . . 14 0.7% Mississippi silverside Menidia audens IN . . . X . 8.27 36.05 124 . . 124 6.3% Total 27 2 11 24 122.42 533.71 1,836 13.90 139 1,975 100% Number Samples 15 10 Species Collected 27 15 *All species listed are Resident Important Species (RIS). No federally threatened or endangered species were collected. Trophic: benthic invertivore (BI), insectivore (IN), omnivore (OM), planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT).

46 Table 15. Spatial statistical comparisons of numbers of species, mean electrofishing catch per unit effort values (number/run), tolerance designations, trophic levels, and non-indigenous individuals, along with species richness and Simpson and Shannon diversity values, collected near Sequoyah Nuclear Plant, summer 2011. Mean (Standard Deviation) Parameter Downstream (TRM 482)Upstream(TRM 490.5) Significant Difference Test Statistic(a)P Value Number of species (per run) Total (Species richness) 10.7 (2.3) 12.1 (3.5) No t= -1.23 0.23 Benthic invertivores 0.5 (0.7) 0.8 (0.8) No Z= -1.28 0.20 Insectivores 3.4 (1.5) 4.5 (1.1) Yes Z= -2.08 0.04 Omnivores 2.2. (1.1) 1.8 (0.9) No Z= 1.44 0.15 Top carnivores 2.3 (0.7) 2.5 (1.4) No Z= 0.09 0.93 Non-indigenous 0.5 (0.5) 0.9 (0.7) No Z= -1.57 0.11 Indigenous 7.9 (2.1) 8.7 (1.9) No t= -1.79 0.28 Tolerant 4.5 (0.8) 4.4 (1.2) No Z= 0.39 0.69 Intolerant 0.5 (1.0) 1.0 (0.8) No Z= -1.90 0.06 Thermally sensitive 0.5 (0.7) 0.6 (0.8) No Z= -0.41 0.68 CPUE (per run) Total 4.05 (1.63) 5.49 (2.10) Yes t= -2.11 0.04 Benthic invertivores 0.05 (0.10) 0.13 (0.21) No Z= -1.50 0.13 Insectivores 2.35 (1.36) 3.13 (1.29) No t= -1.59 0.12 Omnivores 1.26 (1.47) 1.92 (1.68) No Z= -1.14 0.25 Top Carnivores(b) 0.33(0.14) 0.29 (0.22) No t= 0.98 0.33 Non-indigenous 0.13 (0.27) 0.32 (0.39) No Z= -1.65 0.10 Indigenous 4.83 (1.72) 6.06 (2.02) No t= -1.79 0.08 Tolerant 3.47 (1.52) 4.38 (1.92) No t= -1.44 0.16 Intolerant 0.05 (0.09) 0.09 (0.09) Yes Z= -1.99 0.05 Thermally sensitive 0.07 (0.10) 0.13 (0.22) No Z= -0.47 0.64 Diversity indices (per run) Simpson 0.64 (0.14) 0.70 (0.11) No Z= -1.37 0.17 Shannon(b) 5.02 (2.18) 7.02 (4.10) No t= -1.79 0.13 (a) t-Value indicates results of independent two-sample t-test (=0.05). Z-Value indicates results of Mann-Whitney-Wilcoxon Z-test (=0.05) used when raw data could not be normalized using transformation.

(b) Square root or ln(x+1) transformed data used for statistical analyses because raw data were not normally distributed and/or did not have equal variances.

47 Table 16. Spatial statistical comparisons of numbers of species, mean electrofishing catch per unit effort values (number/run), tolerance designations, trophic levels, and non-indigenous individuals, along with species richness and Simpson and Shannon diversity values, collected near Sequoyah Nuclear Plant, autumn 2011.

Mean (Standard Deviation) Parameter Downstream (TRM 482)Upstream(TRM 490.5) Significant Difference Test Statistic(a)P Value Number of species (per run) Total (Species richness) 13.5 (3.0) 12.9 (2.4) No t= 0.6 0.55 Benthic invertivores 0.5 (0.3) 0.5 (0.5) No Z= 0.94 0.35 Insectivores 3.9 (1.8) 4.1 (1.0) No Z= -0.45 0.65 Omnivores 2.3 (1.0) 1.9 (0.6) No Z= 1.16 0.25 Top carnivores 3.1 (1.0) 3.2 (1.7) No Z= 0.04 0.97 Non-indigenous 1.2 (0.4) 1.1 (0.5) No Z= 0.78 0.44 Indigenous(b) 10.1 (3.5) 9.4 (2.2) No t= 0.48 0.63 Tolerant 4.7 (1.7) 3.9 (0.9) No t= 1.62 0.12 Intolerant 0.7 (0.9) 0.8 (0.6) No Z= -0.67 0.50 Thermally sensitive 0.6 (0.5) 0.4 (0.6) No Z= 1.18 0.24 CPUE (per run) Total(b) 3.34 (0.71) 2.81 (0.50) Yes t= 2.34 0.03 Benthic invertivores 0.08 (0.06) 0.09 (0.07) No Z= -0.22 0.83 Insectivores 5.86 (2.98) 4.80 (3.25) No t= 0.93 0.36 Omnivores 3.19 (1.36) 2.60 (1.54) No t= 1.16 0.25 Top Carnivores 0.52 (0.27) 0.50 (0.47) No Z= 0.94 0.35 Non-indigenous 4.11 (3.41) 0.56 (0.50) Yes Z= 3.43 0.0006 Indigenous(b) 7.51 (4.37) 7.60 (2.86) No t= -0.30 0.76 Tolerant 4.95 (2.66) 6.60 (2.74) No t= -1.67 0.11 Intolerant 0.05 (0.07) 0.10 (0.11) No Z= -1.53 0.13 Thermally sensitive 0.05 (0.05) 0.03 (0.05) No Z= 1.18 0.24 Diversity indices (per run) Simpson 0.84 (0.06) 0.83 (0.12) No Z= -0.33 0.74 Shannon 9.1 (2.1) 8.9 (2.6) No t= 0.16 0.87 (a) t-Value indicates results of independent two-sample t-test (=0.05). Z-Value indicates results of Wilcoxon Rank-Sum Z-test (=0.05) used when raw data could not be normalized using transformation. (b) Square root or ln(x+1) transformed data used for statistical analyses because raw data were not normally distributed and/or did not have equal variances.

48 Table 17. Summary of RFAI scores from sites located directly upstream and downstream of Sequoyah Nuclear Plant as well as scores from sampling conducted during autumn 1993-2011 as part of the Vital Signs Monitoring Program in Chickamauga Reservoir. Station Location 1993 1994 19951996199719992000200120022003 20042005200620072008200920102011Average Inflow TRM 529.0 52 52 48 42 44 42 44 46 48 48 42 42 42 42 44 44 44 50 45 Transition SQN Upstream TRM 490.5 51 40 48 44 39 45 46 45 51 42 49 46 47 44 34 41 39 35 44 Forebay SQN Downstream TRM 482.0 --- --- --- 47 --- 41 48 46 43 45 41 39 35 38 38 37 39 35 41 Forebay TRM 472.3 43 44 47 --- 40 45 45 48 46 43 43 46 43 41 41 42 40 34 43 Hiwassee River Embayment HiRM 8.5 46 39 39 --- 40 43 43 47 --- 36 42 45 --- 41 --- 42 --- 37 42 *TRM 482 scored with forebay criteria, TRM 490.5 scored with transition criteria (Refer to Table 4). **RFAI Scores: 12-21 ("Very Poor"), 22-31 ("Poor"), 32-40 ("Fair"), 41-50 ("Good"), or 51-60 ("Excellent")

49 Table 18. Comparison of mean density per square meter of benthic taxa collected at upstream and downstream sites near SQN during August and October 2011. DOWNSTREAM UPSTREAM TRM 481.3 TRM 483.4 TRM 488.0 TRM 490.5 Summer Autumn Summer Autumn Summer Summer Autumn Metric Obs Rating Obs Rating Obs Rating Obs Rating Obs Rating Obs Rating Obs Rating 1. Average number of taxa 9.0 5 7.8 5 13.6 5 13.6 5 7.0 5 7.2 5 6.6 3 2. Proportion of samples with long-lived organisms 0.8 3 0.7 3 0.8 3 0.8 3 1.0 5 0.4 1 0.8 3 3. Average number of EPT taxa 0.9 3 1.0 5 1.2 5 0.9 3 0.8 3 0.2 1 0.5 1 4. Average proportion of oligochaete individuals 35.6 3 29.4 3 54.4 1 48.1 1 15.5 3 7.2 5 14.8 3 5. Average proportion of total abundance comprised by the two most abundant taxa 73.7 5 78.6 5 75.5 5 77.0 5 82.8 3 86.4 3 84.5 3 6. Average density excluding chironomids and oligochaetes 235.0 3 181.7 3 525.0 5 1685.0 5 470.0 3 396.7 3 263.3 1 7. Zero-samples - proportion of samples containing no organisms 0 5 0 5 0 5 0 5 0 5 0 5 0 5 Benthic Index Score 27 29 29 27 27 23 19 Good Good Good Good Good Fair Fair *TRM 481.3 and 483.4 scored with forebay criteria, TRM 488.9 and 490.5 scored with transition criteria (Refer to Table 5). Reservoir Benthic Index Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), 30-35 ("Excellent")

Table 19. Summary of RBI Scores from Sites Located Directly Upstream and Downstream of Sequoyah Nuclear Plant as Well as Scores from Sampling Conducted as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir. Station Location 1994 19951997199920002001200220032004 2005 200620072008200920102011 Average Inflow TRM 527.4 --- --- --- --- --- 29 27 33 35 31 --- 23 23 23 21

  • 27 Inflow TRM 518.0 19 31 25 21 23 29 23 27 35 29 33 25 --- 31 --- 27 27 Transition SQN Upstream TRM 490.5 33 29 31 31 23 25 25 31 31 31 27 21 17 27 23 19 27 Forebay SQN Downstream TRM 482.0 --- --- --- --- 23 31 29 29 33 31 31 25 25 23 29 --- 28 Forebay TRM 472.3 31 27 29 25 27 27 21 27 29 27 29 19 25 23 --- 21 26 Hiwassee River Embayment HiRM 8.5 17 27 25 21 --- 21 --- 31 --- 25 --- 13 --- 19 --- 19 22 * - Sampling was conducted, but data was not available at the time this report was issued. Reservoir Benthic Index Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), 30-35 ("Excellent") 50 51 Table 20. Comparison of mean density per Square Meter of Benthic Taxa collected with a Ponar Dredge along Transects Upstream and Downstream of Sequoyah Nuclear Plant, Chickamauga Reservoir, Summer and Autumn 2011. Taxa Summer Downstream TRM 481.3 Autumn Downstream TRM 481.3 Summer Downstream TRM 483.4 Autumn Downstream TRM 483.4 Summer Upstream TRM 488.0 Summer Upstream TRM 490.5 Autumn Upstream TRM 490.5 Insecta Diptera Chironomidae Ablabesmyia annulata 5 8 2 2 13 7 7 Ablabesmyia mallochi 2 ----- 3 ----- ----- ----- ----- Ablabesmyia rhamphe gp. 7 ----- 10 13 ----- ----- ----- Ablabesmyia sp. ----- ----- ----- ------ ----- 3 ----- Chironomidae 3 2 ----- ------ ----- ----- ----- Chironomus crassicaudatus 10 2 10 ------ 7 73 22 Chironomus decorus gp. 2 2 ------ ------ ----- ------ ----- Chironomus major 15 2 ------ ------ ----- 27 2 Chironomus sp. 5 ------ ------ ------ ------ ------ ------ Cladopelma sp. ------ ------ ------ ------ ------ ------ 2 Cladotanytarsus sp. ------ ------ 5 2 ------ ------ 15 Coelotanypus sp. 135 23 35 12 217 410 ------ Coelotanypus tricolor ------ 205 ------- 103 ------ ------ 292 Clinotanypus sp. ------ ------ ------- 2 ------ ------ ------ Cryptochironomus sp. 7 7 2 7 3 ------ 3 Cricotopus sp. ------ ------ ------- 2 ------ ------ ------- Cricotopus reverses gp. ------ 2 ------- -------- ------ ------ ------- Dicrotendipes lucifer ------ ------- 58 45 ------ ------ ------- Dicrotendipes modestus ------ ------- 12 53 ------ ------ ------- Dicrotendipes neomodestus 2 2 28 5 ------ ------ ------- Dicrotendipes simpsoni ------ ------- 3 3 ------ ------ ------- Dicrotendipes sp. ------ ------- 2 2 ------ ------ ------- Glyptotendipes sp. ------ 2 27 3 ------ ------ ------- Hydrobaenus sp. 2 ------- ------- ------- ------ ------ ------- Microtendipes pedellus gp. 2 ------- ------- ------- ------ ------ ------- Nanocladius alternantherae ------ ------- ------- 2 ------ ------ ------- Nanocladius distinctus ------ ------- 3 5 ------ ------ ------- Orthocladius sp. ------ ------- 2 ------- ------ ------- ------- Parachironomus carinatus ------- ------- 7 3 ------ ------- ------- Parachironomus frequens ------- -------- ------- 7 ------- ------- ------- Parachironomus sp. ------- ------- ------- 2 ------- ------- ------- Polypedilum halterale gp. ------- 2 3 ------- ------- ------- ------- Procladius sp. 5 2 2 2 7 ------- 5 Pseudochironomus sp. ------- ------- ------- 2 ------- ------- -------

52 Table 20 (continued). Taxa Summer Downstream TRM 481.3 Autumn Downstream TRM 481.3 Summer Downstream TRM 483.4 Autumn Downstream TRM 483.4 Summer Upstream TRM 488.0 Summer Upstream TRM 490.5 Autumn Upstream TRM 490.5 Chironomidae (Cont.) Tanytarsus sp. 2 3 ------- 5 ------- ------- ------- Thienemanniella lobapodema ------- ------- ------- ------- 10 ------- ------- Ceratopogonidae 3 ------- ------- ------- ------- ------- 2 Argia sp. ------- ------- 2 ------- ------- ------- ------- Palpomyia sp. ------- ------- ------- ------- ------- 7 ------- Chaoboridae ------- ------- ------- ------- ------- ------- ------- Chaoborus punctipennis 115 67 22 2 63 260 10 Ephemeroptera Ephemeridae Hexagenia limbata 28 23 3 13 20 3 7 Hexagenia sp. 2 ------- ------- 2 ------- ------- 2 Heptageniidae Stenacron interpunctatum 2 3 ------- ------- ------- ------- ------- Caenidae Caenis sp. ------- ------- ------- ------- ------- ------- 2 Trichoptera Leptoceridae Oecetis sp. 7 8 20 12 7 ------- 3 Polycentropodidae Cyrnellus fraternus 3 ------- 17 18 ------- ------- ------- Polycentropus sp. ------- ------- ------- ------- ------- ------- 2 Hydroptilidae Orthotrichia sp. ------- 2 3 ------- ------- ------- ------- Ostracoda Podocopa Candoniidae Candona sp. 3 70 ------- 58 ------- 7 22 Ostracoda 5 2 3 ------- ------- ------- ------- Brachiopoda Cladocera Daphnidae Ceriodaphnia 2 ------- ------- ------- ------- ------- ------- Sididae Sida crystallina 2 2 32 5 ------- ------- 3 53 Table 20 (continued). Taxa Summer Downstream TRM 481.3 Autumn Downstream TRM 481.3 Summer Downstream TRM 483.4 Autumn Downstream TRM 483.4 Summer Upstream TRM 488.0 Summer Upstream TRM 490.5 Autumn Upstream TRM 490.5 Oligocheata Haplotaxida Tubificidae Aulodrilus piqueti 392 33 27 77 7 3 2 Branchiura sowerbyi 3 2 10 3 ----- ----- ----- Limnodrilus hoffmeisteri 10 13 7 93 20 ----- 10 Limnodrilus cervix ----- 2 ----- ----- ----- ----- ----- Tubificidae 168 75 52 542 60 70 120 Naididae Dero sp. 60 18 855 822 7 ----- ----- Naididae 3 3 137 167 ----- ----- 12 Nais cf. pardalis ----- ----- 30 2 ----- ----- ----- Nais sp. ----- ----- 22 40 ----- ----- 5 Prisitina breviseta ----- 2 ----- ----- ----- ----- 5 Pristina leidyi ----- ----- 2 ----- ----- ----- ----- Pristina sp. ----- 2 ----- 25 ----- ----- ----- Slavina appendiculata ----- ----- 15 18 ----- ----- ----- Stylaria lacustris ----- ----- ----- 410 ----- ----- ----- Branchiobdellida Branchiodellida ----- ----- ----- 2 ----- ----- ----- Bivalvia Veneroida Corbiculidae Corbicula fluminea 42 38 98 212 223 67 67 Dreissenidae Dreissena polymorpha ------- ------- 77 198 ------- ------- ------- Sphaeriidae Eupera cubensis ------- ------- 2 ------- ------- ------- ------- Musculium transversum 100 62 27 138 187 283 165 Pisidium sp. 20 12 12 5 20 27 3 Sphaeriidae ------- ------- ------- 2 ------- ------- ------- Unionoida Unoinidae Utterbackia imbecillis 2 ------- ------- 5 ------- ------- ------- Truncilla truncata ------- ------- ------- ------- ------- ------- 2 Gastropoda Mesogastropoda Viviparidae Viviparus sp. 7 ------- 13 55 3 ------- -------

54 Table 20 (continued). Taxa Summer Downstream TRM 481.3 Autumn Downstream TRM 481.3 Summer Downstream TRM 483.4 Autumn Downstream TRM 483.4 Summer Upstream TRM 488.0 Summer Upstream TRM 490.5 Autumn Upstream TRM 490.5 Gastropoda (cont.) Campeloma decisum ------- ------- 2 7 ------- ------- 2 Hydrobiidae Amnicola limosa ------- ------- 3 2 ------- ------- ------- Pleuroceridae Pleurocera canaliculata ------- ------- 3 10 ------- ------- 3 Basommatophora Planorbidae Menetus dilatatus ------- ------- 2 ------- ------- ------- ------- Malacostraca Amphipoda Crangonyctidae Crangonyx sp. 2 ------- ------- 8 ------- ------- ------- Gammaridae Gammarus sp. ------- ------- 7 3 ------- ------- ------- Talitrida Hyalella azteca ------- 3 ------- ------- ------- ------- ------- Maxillopoda Copepoda Cyclopoida 5 ------- 3 5 3 7 2 Harpacticoida ------- ------- 2 ------- ------- ------- ------- Turbellaria Tricladida Planariidae Dugesia tigrina 2 2 185 625 ------- ------- ------- Cura foremanii ------- 2 ------- ------- ------- ------- ------- Hirudinea Rhynchobdellida Glossiphoniidae Glossiphoniidae sp. ------- ------- 12 88 ------- 3 ------- Helobdella stagnalis 15 22 17 165 10 3 3 Helobdella sp. ------- 2 2 73 ------- ------- ------- Helobdella triserialis ------- ------- 8 13 ------- ------- ------- Placobdella montifera ------- 3 ------- ------- ------- ------- ------- Pharyngobdellida Erpobdellidae Erpobdellidae ------- ------- 3 28 ------- ------- -------

Table 20 (continued). Taxa Summer Downstream TRM 481.3 Autumn Downstream TRM 481.3 Summer Downstream TRM 483.4 Autumn Downstream TRM 483.4 Summer Upstream TRM 488.0 Summer Upstream TRM 490.5 Autumn Upstream TRM 490.5 Nematoda Nematoda Nematoda 2 ------- 2 ------- ------- 3 2 Arachnoidea Unoinicolidae Unionicola sp. ------- 2 ------- ------- ------- ------- 8 Acariformes Hygrobatidae Atractides sp. ------- ------- 2 ------- ------- ------- 2 Hydrozoa Hydroida Hydridae Number of samples 10 10 10 10 5 5 10 Mean Density per meter² 1,205 735 1,883 4,283 887 1,263 810 Taxa Richness 42 40 54 58 20 18 36 Sum of area sampled (meters²) 0.60 0.60 0.60 0.60 0.30 0.30 0.60 55 56 Table 21. Individual Metric Ratings and the Overall RBI Field Scores for Downstream and Upstream Sampling Sites Near SQN, Chickamauga Reservoir, Autumn 2000-2010. Reservoir Benthic Index Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), 30-35 ("Excellent"). Downstream (TRM 482.0) 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Metric Obs Score Obs ScoreObsScoreObsScoreObsScoreObsScore ObsScoreObsScoreObsScoreObsScoreObsScore Avg. Number of Taxa 3.7 3 6.2 5 5.4 5 5.7 5 6.3 5 6.6 5 4.9 5 4.1 3 5.8 5 4.2 3 5 5 % Long-Lived Organisms 0.9 5 0.8 5 1 5 0.6 3 1 5 0.9 5 0.9 5 0.6 3 0.6 3 0.7 3 0.9 5 Avg. Number of EPT Taxa 0.3 1 0.6 3 0.4 1 0.3 1 0.5 3 0.7 3 0.7 3 0.5 3 0.6 3 0.5 3 0.5 3 % as Oligochaetes 27.9 3 27.1 3 19.43 9.4 5 8.8 5 15 3 17.3 3 6.3 5 21.7 3 4.4 5 11.7 5 % as Dominant Taxa 87.6 3 80.8 5 78.65 79.85 68.4 5 79 5 78.1 5 90.6 3 83.9 3 83.9 3 81.3 5 Density excluding chironomids and oligochaetes 230 3 348.3 5 365 5 580 5 563.35 573.35 265 5 125 3 166.73 104.41 98.3 1 Number of Samples with Zero Organisms 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 Overall Score 23 31 29 29 33 31 31 25 25 23 29 Upstream (TRM 490.5) 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Metric Obs Score Obs ScoreObsScoreObsScoreObsScoreObsScore ObsScoreObsScoreObsScoreObsScoreObsScore Avg. Number of Taxa 4.7 5 6 5 6.4 5 7.4 5 7.2 5 6.8 5 5.4 5 4.7 5 5.4 5 5 5 4.4 5 % Long-Lived Organisms 0.9 5 0.9 5 1 5 0.9 5 0.9 5 0.9 5 0.8 5 0.5 3 0.3 1 0.8 5 0.7 3 Avg. Number of EPT Taxa 0.3 1 0.4 3 0.2 1 0.7 3 0.7 3 0.9 5 0.5 3 0.3 1 0.1 1 0.6 3 0.7 3 % as Oligochaetes 7.7 5 14.8 3 8.4 5 10.75 6.4 5 4.4 5 2.5 5 5.2 5 16.7 3 7.2 5 1.1 5 % as Dominant Taxa 88.4 1 79.4 3 85 3 71 5 78 5 79.8 3 83.1 3 93.4 1 95 1 81.2 3 91.8 1 Density excluding chironomids and oligochaetes 218.3 1 230 1 168.61 341.73 571.73 479.23 223.31 56.7 1 31.7 1 81.7 1 181.71 Number of Samples with Zero Organisms 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 Overall Score 23 25 25 31 31 31 27 21 17 27 23 57 Table 22. Mean percent composition of major phytoplankton groups at sites sampled upstream and downstream of SQN in August and October, 2011. August 25, 2011 October 10, 2011 Division TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 Bacillariophyta 0 0 1 0 36 38 39 63 Chlorophyta 1 1 2 1 16 16 13 11 Chrysophyta 0 0 0 0 --- --- --- --- Cryptophyta 0 0 0 0 30 34 36 21 Cyanophyta 99 98 96 98 16 12 12 11 Euglenophyta 0 0 0 0 1 0 --- 0 Pyrrophyta 0 0 0 0 1 0 0 --- *To enhance pattern recognition, percentages are rounded to whole numbers, and values may not add to 100. "0" values indicate percentages less than 0.5%. Blank values indicate no individuals of the taxa collected. Table 23. Comparison of the similarity of phytoplankton taxa within paired replicate samples. August 25, 2011 October 10, 2011 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Replicate Taxa Richness 37 39 36 40 36 43 33 40 23 25 21 24 19 22 15 15 Combined Taxa Richness 43 46 49 48 32 30 27 19 Species Shared 33 30 30 25 16 15 14 11 Percent Shared 76.7% 65.2% 61.2% 52.1% 50.0% 50.0% 51.9% 57.9%

Table 24. Taxa richness of the main phytoplankton groups. Group Total Number of Taxa August October Combined Bacillariophyta 9 12 16 Chlorophyta 31 14 37 Chrysophyta 7 --- 7 Cryptophyta 2 1 2 Cyanophyta 14 7 18 Euglenophyta 1 2 2 Pyrrophyta 3 2 4 Total Taxa Richness 67 38 86 Table 25. Percent Similarity Index for comparison of phytoplankton communities among sites. Phytoplankton - Percent SimilarityaStation Comparison August 25, 2011 October 10, 2011 TRM 481.1 - TRM 483.4 83 76 - TRM 487.9 85 71 - TRM 490.7 75 63 TRM 483.4 - TRM 487.9 87 80 - TRM 490.7 81 63 TRM 487.9 - TRM 490.7 84 63 a. Percent Similarity comparison of two communities Table 26. Phytoplankton taxa and density (cells/ml) data for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. Abbreviations "R1" and R2" designate replicate samples. TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 August October August October August October August October Division Taxon R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Bacillariophyta Achnanthes 30.3 34.1 28.4 Anomoeneis 56.8 Aulacoseira 151.5 151.5 74.9 66.1 60.6 56.8 90.4 74.9 170.4 166.5 51.0 68.3 56.8 69.1 76.5 Cyclotella 568.0 814.1 17.6 22.0 333.2 312.4 20.9 16.5 2044.7 1908.4 23.1 20.9 710.0 1164.4 2.2 6.6 Nitzschia 68.2 265.1 3.3 2.2 121.2 113.6 3.3 702.9 306.7 4.4 3.3 56.8 170.4 0.5 1.0 Skeletonema 45.4 75.7 397.6 357.8 454.4 227.2 Stephanodiscus 18.9 60.6 2.2 Surirella 28.4 Synedra 22.7 113.6 12.1 9.9 30.3 56.8 16.5 9.9 68.2 5.5 6.6 8.8 28.4 5.9 5.6 Achnanthidium 1.1 3.3 1.1 0.7 0.1 2.9 1.5 Cocconeis 2.2 1.1 0.1 0.7 Cymbella 0.1 0.7 0.1 0.7 0.5 Fragilaria 50.7 63.9 86.0 50.7 72.7 52.9 83.7 54.4 Gyrosigma 0.5 Melosira 0.2 0.4 Navicula 0.1 0.7 0.1 3.3 2.2 Bacillariophyta Total 856 1,439 161 168 636 625 223 153 3,384 2,779 163 158 1,221 1,676 165 146 Chlorophyta Carteria 22.7 18.9 28.4 Chlamydomonas 386.2 302.9 5.5 6.6 121.2 198.8 49.6 20.9 681.6 511.2 23.1 16.5 198.8 142.0 9.6 6.6 Chlorococcaceae 22.7 56.8 121.2 113.6 136.3 408.9 170.4 142.0 Chlorogonium 34.1 Coelastrum 75.7 272.6 408.9 Cosmarium 28.4 Crucigenia 121.2 5.7 0.6 0.8 894.6 0.3 7.6 Diacanthos 34.1 Dictyosphaerium 249.9 121.2 227.2 136.3 113.6 312.4 Euastrum 22.7 Eudorina 484.7 Golenkinia 28.4 34.1 34.1 28.4 Kirchneriella 136.3 Lagerheimia 30.3 28.4 34.1 85.2 Micractinium 113.6 121.2 113.6 170.4 113.6 Monomastix 28.4 Monoraphidium 249.9 151.5 4.4 151.5 426.0 4.4 443.0 920.1 0.1 397.6 227.2 58 Table 26 (continued). TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 August October August October August October August October Division Taxon R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Chlorophyta Mougeotia 22.7 (continued) Oocystis 18.9 60.6 142.0 545.3 272.6 113.6 113.6 Pandorina 363.5 87.8 87.8 Pediastrum 76.8 208.3 22.8 242.3 87.8 22.8 1.8 1056.4 0.8 113.6 2.1 Pyramichlamys 22.7 56.8 28.4 Quadrigula 28.4 Scenedesmus 284.0 1022.4 0.4 10.5 1272.3 426.0 3.1 13.2 1363.1 1158.7 16.1 17.6 1703.9 1168.4 15.6 6.1 Schroederia 22.7 75.7 30.3 28.4 34.1 28.4 Sphaerocystis 272.6 Staurastrum 28.4 0.7 34.1 0.1 0.0 Teilingia 21.9 Tetraedron 45.4 0.7 30.3 113.6 34.1 34.1 0.7 113.6 85.2 Tetrastrum 75.7 5.7 113.6 0.4 136.3 136.3 2.9 Treubaria 30.3 28.4 34.1 Actinastrum 17.6 11.4 8.8 0.8 0.4 17.6 3.8 0.4 Ankistrodesmus 8.8 5.7 0.2 Chlorella 23.1 16.5 13.2 7.7 3.3 3.3 0.1 Closterium 0.7 Elakatothrix 0.6 1.0 Selenastrum 9.4 0.2 1.4 Chlorophyta Total 1,792 2,265 98 52 2,938 2,189 104 50 3,987 5,521 47 58 3,126 3,306 32 21 Chrysophyta Chrysococcus 28.4 Conradiella 132.5 242.3 198.8 408.9 204.5 170.4 340.8 Erkenia 272.6 208.3 121.2 113.6 408.9 937.2 568.0 198.8 Goniochloris 34.1 28.4 Gonyostomum 5.5 5.5 5.5 Kephyrion 28.4 Mallomonas 68.2 68.2 Chrysophyta Total 273 341 364 312 920 1,215 801 573 Cryptophyta Cryptomonas 318.1 397.6 146.6 123.4 30.3 56.8 188.4 139.9 306.7 681.6 157.6 137.7 426.0 284.0 53.6 49.2 Rhodomonas 454.4 284.0 121.2 113.6 238.6 1465.4 568.0 312.4 Cryptophyta Total 772 682 147 123 151 170 188 140 545 2,147 158 138 994 596 54 49 59 60 Table 26 (continued). TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 August October August October August October August October Division Taxon R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Cyanophyta Anabaena 43.9 738.4 0.9 76.8 1.5 886.1 477.1 1.9 74.4 Anabaenopsis 153.6 Aphanocapsa 6179.6 17561.7 3513.9 2186.7 5316.3 477.1 10947.7 6957.8 Chroococcaceae 98554.4 65702.9 78022.2 70835.9 100607.6 104714.0 151938.0 170416.9 Chroococcus 795.2 75.7 22.0 0.2 363.5 340.8 11.4 681.6 477.1 2.9 227.2 Cyanocatena 21900.9 10266.1 14783.2 Cyanogranis 59789.6 158097.6 65702.9 94447.9 68988.0 98760.2 123192.9 68988.0 Cylindrospermopsis 2805.8 2515.9 1206.5 1318.4 1243.9 1756.2 666.0 467.4 Dactylococcopsis 22.7 56.8 136.3 142.0 142.0 Leptolyngbya 32.8 Limnothrix 25.7 2.3 Lyngbya 3358.7 1416.2 1269.2 1817.5 963.3 1613.1 1363.2 3908.7 Merismopedia 8497.0 5566.2 11.4 1931.1 2.4 59.3 272.6 2453.7 454.4 681.6 Oscillatoria 6410.1 3691.9 4543.8 4158.1 4089.5 6043.3 8503.5 7403.6 Planktothrix 48.5 27.9 Pseudanabaena 0.9 34.3 19.8 Synechococcus 61664.6 110873.7 30113.8 34989.9 40203.9 62789.2 22585.4 35415.9 Synechocystis 5339.0 4998.2 4453.0 3635.1 7497.3 6986.2 5963.8 5310.6 Cyanophyta Total 253,461 371,295 56 87 211,090 226,004 4 107 230,750 286,683 22 77 325,757 314,856 0 28 Euglenophyta Euglena 45 11 6 7 15 0 1 5 5 1 Trachelomonas 1 Euglenophyta Total 45 11 6 7 15 0 3 5 5 1 Pyrrophyta Glenodinium 23 5 11 28 Gymnodinium 45 38 30 34 28 Peridinium 45 5 2 0 0 11 1 28 Ceratium 0 0 Pyrrophyta Total 114 49 2 30 0 0 11 45 1 28 57 Total Phytoplankton Cell Count 257,313 376,081 467 439 215,224 229,301 519 453 239,603 298,391 389 432 331,933 321,065 251 244 61 Table 27. Percentage Composition of phytoplankton for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. August 25, 2011 October 10, 2011 Taxon TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Bacillariophyta Achnanthes --- --- 0 --- --- 0 --- 0 --- --- --- --- --- --- --- --- Anomoeneis --- --- --- 0 --- --- --- --- --- --- --- --- --- --- --- --- Aulacoseira 0 0 0 0 0 0 --- 0 16 15 17 17 13 16 27 31 Cyclotella 0 0 0 0 1 1 0 0 4 5 4 4 6 5 1 3 Nitzschia 0 0 0 0 0 0 0 0 1 1 1 --- 1 1 0 0 Skeletonema 0 0 --- --- 0 0 0 0 --- --- --- --- --- --- --- --- Stephanodiscus --- 0 0 --- --- --- --- --- --- --- 0 --- --- --- --- --- Surirella --- --- --- 0 --- --- --- --- --- --- --- --- --- --- --- --- Synedra 0 0 0 0 0 0 --- 0 3 2 3 2 2 2 2 2 Achnanthidium --- --- --- --- --- --- --- --- --- 0 1 0 0 0 1 1 Cocconeis --- --- --- --- --- --- --- --- 0 0 --- 0 0 --- --- --- Cymbella --- --- --- --- --- --- --- --- 0 0 0 --- --- 0 0 --- Fragilaria --- --- --- --- --- --- --- --- 11 15 17 11 19 12 33 22 Gyrosigma --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 0 Melosira --- --- --- --- --- --- --- --- --- --- --- --- 0 0 --- --- Navicula --- --- --- --- --- --- --- --- 0 0 --- 0 1 1 --- --- Bacillariophyta Total 0 0 0 0 1 1 0 1 34 38 43 34 42 36 66 60 Chlorophyta Carteria 0 0 --- 0 --- --- --- --- --- --- --- --- --- --- --- --- Chlamydomonas 0 0 0 0 0 0 0 0 1 2 10 5 6 4 4 3 Chlorococcaceae 0 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Chlorogonium --- --- --- --- --- 0 --- --- --- --- --- --- --- --- --- --- Coelastrum --- 0 --- --- 0 0 --- --- --- --- --- --- --- --- --- --- Cosmarium --- --- --- 0 --- --- --- --- --- --- --- --- --- --- --- --- Crucigenia --- --- 0 --- --- --- --- 0 --- --- 1 0 --- 0 0 3 Diacanthos --- --- --- --- --- 0 --- --- --- --- --- --- --- --- --- --- Dictyosphaerium 0 --- 0 0 --- 0 0 0 --- --- --- --- --- --- --- --- Euastrum 0 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Eudorina --- --- 0 --- --- --- --- --- --- --- --- --- --- --- --- --- Golenkinia --- --- --- 0 0 0 --- 0 --- --- --- --- --- --- --- --- Kirchneriella --- --- --- --- 0 --- --- --- --- --- --- --- --- --- --- --- Lagerheimia --- --- 0 0 --- 0 0 --- --- --- --- --- --- --- --- --- Micractinium --- 0 0 0 0 --- 0 --- --- --- --- --- --- --- --- --- Monomastix --- --- --- 0 --- --- --- --- --- --- --- --- --- --- --- --- Monoraphidium 0 0 0 0 0 0 0 0 1 --- --- 1 --- 0 --- --- Mougeotia 0 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Oocystis --- 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Pandorina 0 0 --- --- --- --- 0 --- --- --- --- --- --- --- --- --- Pediastrum 0 0 0 0 --- 0 --- 0 5 --- 4 0 0 --- 1 --- Pyramichlamys 0 0 --- --- --- --- --- 0 --- --- --- --- --- --- --- --- Quadrigula --- --- --- --- --- --- 0 --- --- --- --- --- --- --- --- --- Scenedesmus 0 0 1 0 1 0 1 0 0 2 1 3 4 4 6 3 62 Table 27. (Continued) August 25, 2011 October 10, 2011 Taxon TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 (Chlorophyta) Schroederia 0 0 0 0 --- 0 --- 0 --- --- --- --- --- --- --- --- Sphaerocystis --- --- --- --- --- 0 --- --- --- --- --- --- --- --- --- --- Staurastrum --- --- --- 0 0 --- --- --- --- --- --- 0 0 --- --- 0 Teilingia --- --- --- --- --- --- --- 0 --- --- --- --- --- --- --- --- Tetraedron 0 --- 0 0 0 0 0 0 --- 0 --- --- --- 0 --- --- Tetrastrum --- 0 --- 0 0 0 --- --- 1 --- 0 --- 1 --- --- --- Treubaria --- --- 0 0 --- 0 --- --- --- --- --- --- --- --- --- --- Actinastrum --- --- --- --- --- --- --- --- 4 3 2 0 0 4 2 0 Ankistrodesmus --- --- --- --- --- --- --- --- 2 1 --- --- --- 0 --- --- Chlorella --- --- --- --- --- --- --- --- 5 4 3 2 1 1 --- 0 Closterium --- --- --- --- --- --- --- --- --- 0 --- --- --- --- --- --- Elakatothrix --- --- --- --- --- --- --- --- 0 --- --- --- --- --- 0 --- Selenastrum --- --- --- --- --- --- --- --- 2 --- 0 --- --- 0 --- --- Chlorophyta Total 1 1 1 1 2 2 1 1 21 12 20 11 12 14 13 9 Chrysophyta Chrysococcus --- --- --- --- --- --- 0 --- --- --- --- --- --- --- --- --- Conradiella --- 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Erkenia 0 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Goniochloris --- --- --- --- 0 --- 0 --- --- --- --- --- --- --- --- --- Gonyostomum --- --- --- --- --- 0 0 0 --- --- --- --- --- --- --- --- Kephyrion --- --- --- --- --- --- --- 0 --- --- --- --- --- --- --- --- Mallomonas --- --- --- --- 0 0 --- --- --- --- --- --- --- --- --- --- Chrysophyta Total 0 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Cryptophyta Cryptomonas 0 0 0 0 0 0 0 0 31 28 36 31 41 32 21 20 Rhodomonas 0 0 0 0 0 0 0 0 --- --- --- --- --- --- --- --- Cryptophyta Total 0 0 0 0 0 1 0 0 31 28 36 31 41 32 21 20 Cyanophyta Anabaena 0 0 --- 0 0 0 --- --- 0 --- 0 --- 0 17 --- --- Anabaenopsis --- --- --- --- --- --- --- 0 --- --- --- --- --- --- --- --- Aphanocapsa 2 5 2 1 2 0 3 2 --- --- --- --- --- --- --- --- Chroococcaceae 38 17 36 31 42 35 46 53 --- --- --- --- --- --- --- --- Chroococcus 0 0 0 0 0 0 --- 0 5 0 --- 3 --- 1 --- --- Cyanocatena --- --- 10 4 --- --- --- 5 --- --- --- --- --- --- --- --- Cyanogranis 23 42 31 41 29 33 37 21 --- --- --- --- --- --- --- --- Cylindrospermopsis 1 1 1 1 1 1 0 0 --- --- --- --- --- --- --- --- Dactylococcopsis 0 0 --- --- --- 0 0 0 --- --- --- --- --- --- --- --- Leptolyngbya --- --- --- --- --- --- --- --- 7 --- --- --- --- --- --- --- Limnothrix --- --- --- --- --- --- --- --- --- 6 --- 1 --- --- --- --- Lyngbya 1 0 1 1 0 1 0 1 --- --- --- --- --- --- --- --- Merismopedia 3 1 --- 1 0 1 0 0 --- 3 0 13 --- --- --- --- Oscillatoria 2 1 2 2 2 2 3 2 --- --- --- --- --- --- --- --- Planktothrix --- --- --- --- --- --- --- --- --- 11 --- --- --- --- --- 11 Pseudanabaena --- --- --- --- --- --- --- --- --- 0 --- 8 5 --- --- --- Synechococcus 24 29 14 15 17 21 7 11 --- --- --- --- --- --- --- --- Synechocystis 2 1 2 2 3 2 2 2 --- --- --- --- --- --- --- --- Cyanophyta Total 99 99 98 99 96 96 98 98 12 20 1 24 6 18 --- 11 63 Table 27. (Continued) August 25, 2011 October 10, 2011 Taxon TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Euglenophyta Euglena 0 0 0 --- 0 --- 0 --- 1 2 0 0 --- --- 0 --- Trachelomonas --- --- --- --- --- --- --- --- --- --- --- 0 --- --- --- --- Euglenophyta Total 0 0 0 --- 0 --- 0 --- 1 2 0 1 --- --- 0 --- Pyrrophyta Glenodinium 0 0 --- --- --- 0 0 --- --- --- --- --- --- --- --- --- Gymnodinium 0 0 0 --- --- 0 --- 0 --- --- --- --- --- --- --- --- Peridinium 0 0 --- --- 0 --- --- 0 --- 1 0 0 --- 0 --- --- Ceratium --- --- --- --- --- --- --- --- --- 0 --- 0 --- --- --- --- Pyrrophyta Total 0 0 0 --- 0 0 0 0 --- 1 0 0 --- 0 --- ---

64 Table 28. Concentrations of chlorophyll a (apparent and corrected), phaeophytin a and the chlorophyll/phaeophytin index values for samples collected upstream and downstream of SQN during 2011. Collection Date Sample Site Replicate Chlorophyll a (µg/L) Phaeophytin a (µg/L) Chlorophyll/Phaeophytin Index Apparent Corrected 08/25/2011 TRM 481.2 R1 13 11 2.2 1.6 R2 14 13 1.5 1.6 TRM 483.4 R1 8 6 2.5 1.5 R2 8 6 2.6 1.5 TRM 487.9 R1 13 13 < 1.0 1.7 R2 15 15 < 1.0 1.7 TRM 490.7 R1 11 10 1.0 1.6 R2 11 9 1.5 1.6 10/10/2011 TRM 481.1 R1 6 5 1.0 1.6 R2 8 7 1.7 1.6 TRM 483.4 R1 10 9 1.4 1.6 R2 13 11 1.6 1.6 TRM 487.9 R1 7 6 1.7 1.5 R2 9 8 1.4 1.6 TRM 490.8 R1 7 5 2.0 1.5 R2 6 6 1.1 1.6 Table 29. Mean percent composition of major zooplankton groups at sites sampled upstream and downstream of SQN in August and October, 2011.

August 25, 2011 October 10, 2011 Group TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 Bivalvia (veliger) --- --- --- --- --- 0 0 --- Cladocera 66 51 65 62 44 59 71 69 Copepoda 32 27 20 23 40 37 23 29 Rotifera 2 22 15 16 16 4 6 2

  • Percentages are rounded to whole numbers, and values may not add to 100. "0" values indicate percentages less than 0.5%. Blank values indicate no individuals of the taxa collected.

65 Table 30. Comparison of the similarity of zooplankton taxa within paired replicate samples. August 25, 2011 October 10, 2011 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Replicate Taxa Richness 8 9 6 7 7 8 7 7 7 7 11 11 8 9 12 9 Combined Taxa Richness 14 8 9 9 9 16 12 13 Species Shared 3 5 6 5 5 6 5 8 Percent Shared 21.4% 62.5% 66.7% 55.6% 55.6% 37.5% 41.7% 61.5% Table 31. Taxa richness of the main zooplankton groups. Group Total Number of Taxa August October Combined Bivalvia --- 2 2 Cladocera 7 8 11 Copepoda 3 9 10 Rotifera 8 7 12 Total Taxa Richness 18 26 35 Table 32. Percent Similarity Index for comparison of zooplankton communities among sites. Zooplankton - Percent Similaritya Station Comparison August 25, 2011 October 10, 2011 TRM 481.1 - TRM 483.4 63 83 - TRM 487.9 69 72 - TRM 490.7 75 74 TRM 483.4 - TRM 487.9 70 86 - TRM 490.7 72 89 TRM 487.9 - TRM 490.7 80 93 a. Percent Similarity comparison of two communities Table 33. Zooplankton taxa and density (organisms/m3) data for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. Abbreviations "R1" and R2" designate replicate samples. TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 August October August October August October August October Taxon R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Bivalvia Corbiculidae Corbicula fluminea (veliger) 9 Dreissenidae Dreissena polymorpha (veliger) 9 9 15 Cladocera Cladocera (immature) 15 Diplostraca Bosminidae Bosmina longirostris 1175 2385 5017 18182 1421 784 2461 3614 596 1083 2895 3762 627 796 5511 5863 Bosminidae (immature) 40 Eubosmina tubicen 18 34 41 Daphiniidae Ceriodaphnia 147 41 79 120 37 14 Daphnia galeata 76 31 Daphnia lumholtzi 73 9 160 30 17 40 Daphnia retrocurva 89 Leptodoridae Leptodora kindtii 38 38 18 Sididae Diaphanosoma birgei 417 1027 958 1238 397 321 111 265 Diaphanosoma brachyurum 14 Sididae (immature) 112 14 40 Ilyocryptidae Ilyocryptus spinifer 9 Macrothricidae Macrothrix sp. 9 Copepoda Calanoida Calanoida 37 3961 12907 247 372 1558 1276 357 80 1006 872 111 44 2020 2193 Temoridae Epischura fluviatilis 34 Eurytemora affinis 377 186 120 15 77 82 120 Eurytemora sp. 673 66 67 Table 33 (continued). TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 August October August October August October August Taxon R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 (Copepoda) Cyclopoida Cyclopoida 1023 1284 453 2918 1019 661 230 370 119 241 137 94 221 265 220 179 Cyclopidae Cyclops sp. 38 41 37 Eucyclops agilis 9 Mesocyclops edax 27 Tropocyclops prasinus 41 20 Harpacticoida Harpacticoida 112 Poecilostomatoida Ergasilidae Ergasilus sp. 18 41 40 Rotifera Flosculariaceae Conochilidae Conochilus unicornis 38 1773 6846 31 2312 416 278 281 503 184 265 96 199 Ploima Brachionidae Brachionus angularis 14 Brachionus calyciflorus 37 38 9 9 Brachionus patulus 9 Brachionus quadridentatus 17 Brachionus quadridentatus f. brevispinus 15 Kellicottia longispina 40 Keratella cochlearis 40 14 Platyias patulus 37 Gastropidae Ascomorpha sp. 44 Lecanidae Lecane sp. 38 Trichocercidae Trichocerca sp. 37 Total Zooplankton Abundance 2842 5064 11657 41751 3707 5449 4930 5462 1866 2326 4632 4917 1327 1769 8122 8734 Table 34. Percentage composition of zooplankton taxa for samples collected at four stations within Chickamauga Reservoir on the Tennessee River - August 25 and October 10, 2011. August 25, 2011 October 10, 2011 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 Bivalvia Corbiculidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Corbicula fluminea (veliger) --- --- --- --- --- --- --- --- --- --- --- 0 --- --- --- --- Dreissenidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Dreissena polymorpha (veliger) --- --- --- --- --- --- --- --- --- --- 0 0 0 --- --- --- Bivalvia Total --- --- --- --- --- --- --- --- --- --- 0 0 0 --- --- --- Cladocera Cladocera (immature) --- --- --- --- --- --- --- --- --- --- --- --- 0 --- --- --- Diplostraca --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Bosminidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Bosmina longirostris 41 47 38 14 32 47 47 45 43 44 50 66 63 77 68 67 Bosminidae (immature) --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 0 Eubosmina tubicen --- --- --- --- --- --- --- --- --- --- 0 --- --- 1 1 --- Daphiniidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Ceriodaphnia --- 3 --- 1 4 5 3 --- --- --- --- --- --- --- 0 --- Daphnia galeata 3 --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- Daphnia lumholtzi --- 1 --- --- --- 7 --- --- --- --- --- 0 1 0 --- 0 Daphnia retrocurva --- --- --- --- --- --- --- 5 --- --- --- --- --- --- --- --- Leptodoridae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Leptodora kindtii 1 --- --- --- --- --- --- --- 0 --- --- 0 --- --- --- --- Sididae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Diaphanosoma birgei 15 20 26 23 21 14 8 15 --- --- --- --- --- --- --- --- Diaphanosoma brachyurum --- --- --- --- --- --- --- --- --- --- --- --- --- --- 0 --- Sididae (immature) --- --- --- --- --- --- --- --- --- 0 --- --- --- --- 0 0 Ilyocryptidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Ilyocryptus spinifer --- --- --- --- --- --- --- --- --- --- 0 --- --- --- --- --- Macrothricidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Macrothrix sp. --- --- --- --- --- --- --- --- --- --- --- 0 --- --- --- --- Cladocera Total 60 72 65 38 57 72 58 65 43 44 50 67 63 78 69 68 Copepoda Calanoida --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Calanoida ---17719382 3431322322182525 Temoridae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Epischura fluviatilis --- --- --- --- --- --- --- --- --- --- --- --- ---1 --- --- Eurytemora affinis --- --- --- --- --- --- --- --- 3 ---420211 Eurytemora sp. --- --- --- --- --- --- --- --- ---2 --- --- --- --- --- --- Cyclopoida --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Cyclopoida 362527126101715 47573232 68 69 Table 34. (Continued) August 25, 2011 October 10, 2011 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 TRM 481.1 TRM 483.4 TRM 487.9 TRM 490.7 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 R1 R2 (Cyclopoida) Cyclops sp. 1 --- --- 1 --- --- 3 --- --- --- --- --- --- --- --- --- Eucyclops agilis --- --- --- --- --- --- --- --- --- --- 0 --- --- --- --- --- Mesocyclops edax --- --- --- --- --- --- --- --- --- --- 1 --- --- --- --- --- Tropocyclops prasinus --- --- --- --- --- --- --- --- --- --- --- --- --- --- 1 0 Harpacticoida --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Harpacticoida --- --- --- --- --- --- --- --- --- 0 --- --- --- --- --- --- Poecilostomatoida --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Ergasilidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Ergasilus sp. --- --- --- --- --- --- --- --- --- --- --- 0 --- --- 1 0 Copepoda Total 37 26 34 20 26 14 28 17 41 40 41 33 25 22 30 29 Rotifera Flosculariaceae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Conochilidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Conochilus unicornis 1 --- 1 42 15 12 14 15 15 16 8 --- 11 --- 1 2 Ploima --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Brachionidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Brachionus angularis --- --- --- --- --- --- --- --- --- --- --- --- --- --- 0 --- Brachionus calyciflorus --- 1 --- --- --- --- --- --- 0 --- 0 0 --- --- --- --- Brachionus patulus --- --- --- --- --- --- --- --- --- --- --- --- --- 0 --- --- Brachionus quadridentatus --- --- --- --- --- --- --- --- --- --- --- --- --- 0 --- --- Brachionus quadridentatus f. brevispinus --- --- --- --- --- --- --- --- --- --- --- --- 0 --- --- --- Kellicottia longispina --- --- --- --- --- 2 --- --- --- --- --- --- --- --- --- --- Keratella cochlearis --- --- --- --- 2 --- --- --- --- --- --- --- --- --- 0 --- Platyias patulus --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- Gastropidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Ascomorpha sp. --- --- --- --- --- --- --- 2 --- --- --- --- --- --- --- --- Lecanidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Lecane sp. 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Trichocercidae --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Trichocerca sp. --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- Rotifera Total 3 2 1 42 17 14 14 17 16 16 9 0 11 1 2 2

  • Percentages are rounded to whole numbers, and values may not add to 100. "0" values indicate percentages less than 0.5%. Blank values indicate no individuals of the taxa collected.

70 Table 35. Wildlife Visual Encounter Survey Results of Shoreline Upstream and Downstream of Sequoyah Nuclear Plant during August (Summer) and October (Autumn) 2011. (RDB = right descending bank, LDB = Left Descending Bank) Season Site Transect Birds Obs. Mammals Obs. August 2011 Upstream RDB Swallow sp. 1 Belted Kingfisher 1 American Crow 4 Turkey Vulture 2 Osprey 1 Great Blue Heron 5 Unidentified Duck 2 Upstream LDB Swallow sp. 2 White-tailed Deer 4 Red-winged Blackbird 5 American Crow 1 Great Blue Heron 5 Downstream RDB Swallow Sp. 3 White-tailed Deer 4 Osprey 2 Wood Duck 1 Great Blue Heron 4 Double-crested Cormorant 2 Downstream LDB Belted Kingfisher 1 Swallow sp. 5 European Starling 30 Green Heron 1 Great Blue Heron 2 October 2011 Upstream RDB Songbird sp. 2 Great Blue Heron 4 Upstream LDB Wren sp. 1 Belted Kingfisher 1 Great Blue Heron 1 Downstream RDB Songbird sp. 6 Eastern Gray Squirrel 1 Belted Kingfisher 3 Blue Jay 1 Northern Mockingbird 1 Double-crested Cormorant 1 Great Blue Heron 5 American Coot 335 American Widgeon 2 Pied-billed Grebe 2 Mallard 5 Downstream LDB Belted Kingfisher 2 Tufted Titmouse 3 Killdeer 2 Sandpiper sp. 2 Songbird sp. 3 Great Blue Heron 7 Wood Duck 15 American Coot 603 Black-crowned Night Heron 1 Gadwall 3 Mallard 13 Green-winged Teal 2 Pied-billed Grebe 2 Double-crested Cormorant 5 71 Table 36. Water temperature (°F) profiles measured at five locations (10%, 30%, 50%, 70%, 90%) from right descending bank along transects located at TRM 486.7 (ambient), TRM 483.4 (discharge), TRM 481.1 (middle of plume), TRM 480.0 (downstream limit of plume), and TRM 478.3 (below plume) on August 25, 2011 (Summer). Green numbers represent ambient temperatures used to characterize the thermal plume. Red numbers represent temperatures 3.6ûF (2°C) or greater above ambient temperature. Depth (m) Ambient TRM 486.7 SQN Discharge TRM 483.4 Middle of Plume TRM 481.1 At Plume Limit TRM 480.0 Below Plume TRM 478.3 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 0.3 82.35 82.63 81.63 81.55 81.59 85.42 85.15 84.92 85.30 84.69 85.28 85.69 86.63 86.22 86.85 85.95 85.51 85.89 86.72 86.77 84.18 84.74 85.19 85.46 85.86 1 81.93 82.38 81.52 81.43 81.54 85.08 85.06 83.52 84.85 84.87 85.03 84.87 85.03 86.04 86.72 85.77 85.08 85.69 84.97 86.16 84.11 84.63 85.03 85.30 85.37 2 81.63 81.50 81.32 81.23 81.41 84.72 84.58 82.58 84.96 84.43 84.69 84.51 84.65 85.32 84.51 84.18 85.21 84.88 83.52 83.98 84.74 84.31 85.33 3 81.36 81.32 81.21 81.68 81.37 82.60 82.96 81.73 84.51 83.32 84.02 84.16 84.40 84.27 84.40 83.93 84.31 83.55 83.95 84.51 84.13 85.32 4 81.25 81.09 81.10 81.05 81.27 82.13 82.40 84.31 84.45 83.75 83.97 84.29 84.24 84.34 83.82 83.84 83.93 84.11 84.11 85.26 5 81.12 81.09 81.03 81.05 82.18 84.22 83.80 83.86 84.25 84.20 84.18 83.59 83.89 83.93 84.06 84.97 6 81.03 81.01 80.73 84.33 83.82 83.66 84.16 84.11 82.96 83.82 83.86 83.84 84.16 7 80.98 80.94 80.65 84.20 83.75 83.75 84.07 83.98 82.58 83.46 83.79 83.82 83.84 8 80.85 80.89 80.65 84.20 82.76 83.12 83.84 83.61 82.36 83.43 83.75 83.80 83.77 9 80.80 80.85 80.65 83.70 82.11 82.94 83.53 83.39 82.17 83.17 83.66 83.75 83.68 10 80.80 80.85 80.65 83.55 82.09 82.85 83.16 83.28 82.11 83.26 83.17 83.71 83.66 11 80.80 80.83 80.64 83.10 81.68 82.49 82.72 83.19 82.11 83.25 82.99 83.66 83.64 12 80.83 80.64 83.14 81.70 82.54 82.47 83.14 82.09 83.10 82.90 82.92 13 80.64 82.67 81.63 82.47 82.20 82.11 83.10 82.80 82.87 14 80.64 82.17 81.59 82.38 82.08 82.11 83.05 82.54 82.63 15 82.18 82.26 82.08 83.01 82.53 82.58 16 82.13 82.26 82.08 82.51 82.58 17 82.06 82.27 82.08 82.51 82.56 18 82.04 82.15 82.08 82.45 82.56 Table 37. Water temperature (°F) profiles measured at five locations (10%, 30%, 50%, 70%, 90%) from right descending bank along transects located at TRM 487 (ambient), TRM 483.4 (discharge), TRM 482.2 (below discharge), TRM 481.0 (downstream limit of plume), and TRM 478.3 (below plume) on September 14, 2011 (Autumn). Green numbers represent ambient temperatures used to characterize the thermal plume. Red numbers represent temperatures 3.6ûF (2°C) or greater above ambient temperature. Depth (m) Ambient TRM 487 SQN Discharge TRM 483.4 Below Discharge TRM 482.2 At Plume Limit TRM 481 Below Plume TRM 480.5 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 10% 30% 50% 70% 90% 0.3 77.18 77.18 77.54 77.36 77.54 81.25 80.42 80.55 80.01 81.68 81.45 81.21 81.14 81.48 81.91 80.15 81.03 81.32 80.53 80.65 80.08 80.04 80.42 79.25 79.45 1 77.00 76.82 77.18 76.64 77.18 80.71 80.29 80.10 79.88 81.09 81.09 80.28 79.79 80.06 80.71 79.61 79.74 79.75 79.66 79.59 78.18 79.14 79.00 78.62 78.76 2 76.64 76.46 76.46 76.46 76.28 82.35 80.08 80.06 79.70 80.58 79.83 79.29 79.20 80.24 78.60 78.60 79.00 79.30 78.80 78.82 78.49 78.48 78.44 77.58 3 76.64 76.46 76.10 76.10 76.10 78.40 79.61 80.06 79.54 80.69 79.74 78.93 79.00 79.39 78.40 78.21 78.04 78.84 78.51 78.71 78.19 78.21 77.52 4 76.46 76.46 75.92 75.20 75.38 78.06 79.97 79.47 80.80 79.47 78.84 78.87 77.83 77.49 78.75 77.61 78.58 78.04 77.94 77.49 5 76.46 75.56 75.20 80.20 79.34 80.64 78.24 78.53 78.71 77.68 77.34 78.69 77.49 78.13 77.81 77.56 6 75.20 75.02 79.02 79.25 80.55 78.37 78.58 77.38 77.32 78.51 77.43 77.74 77.50 7 75.20 75.02 78.49 80.28 78.28 77.32 77.20 77.70 77.45 8 75.02 74.48 77.58 78.49 78.06 77.20 76.93 77.67 77.36 9 75.02 74.48 77.22 77.54 77.67 77.04 76.84 77.58 77.34 10 74.48 74.30 76.15 77.43 77.59 76.96 76.80 77.52 77.09 11 73.58 74.30 76.12 77.36 77.58 76.66 76.69 77.49 76.96 12 73.22 75.97 76.82 77.56 76.28 76.41 77.47 76.23 13 75.94 76.82 77.23 76.21 76.24 77.05 76.19 14 75.87 76.05 76.14 76.08 76.19 15 75.76 75.83 76.08 76.06 1 16 75. 77.07776 75. 8 76 3 17 75. 4 75. 8 18 75. 2 72 Table 38. Seasonal water quality parameters collected along vertical depth profiles downstream (TRM 482) and upstream (TRM 490.5) of the Sequoyah Nuclear Plant in Chickamauga Reservoir on the Tennessee River. Abbreviations: °C -Temperature in degrees Celsius, °F - Temperature in degrees Fahrenheit, Cond - Conductivity, DO - Dissolved Oxygen Summer - TRM 482 LDB Mid-channel RDB Depth ûC °F Cond DOpHDepthûC°FCond DOpHDepthûC°FCondDOpH Downstream Transect 0.3 29.33 84.79 192.8 7.467.910.329.5085.10192.2 8.058.110.329.7385.51192.66.737.74 1.5 29.09 84.36 193.1 7.187.831.529.1584.47192.3 7.557.981.529.3084.74192.87.227.86 3 28.67 83.61 193.0 6.517.67329.1084.38192.4 7.497.95329.0784.33193.87.597.98 5 28.62 83.52 193.1 6.397.64429.0784.33192.5 7.457.93528.7483.73192.48.228.18 628.8583.93192.4 7.177.85 828.6983.64192.0 7.027.80 1228.4083.12191.4 6.557.70 1528.1982.74192.2 6.387.64 1928.0782.53227.5 6.247.63 Middle Transect 0.3 29.60 85.28 192.8 6.897.780.329.3584.83191.6 7.35 0.330.5887.04191.89.128.37 1.5 29.14 84.45 191.6 7.037.811.529.0384.25191.3 7.357.921.529.1984.54191.08.588.21 3 28.59 83.46 192.3 8.058.07328.7983.82191.2 7.167.86328.6985.44190.47.948.02 4.5 28.30 82.94 190.2 8.358.23428.6583.57191.0 7.237.87 828.3583.03191.7 6.947.79 1227.9382.27191.8 6.607.71 14.527.8782.17191.2 6.537.67 Upstream Transect 0.3 28.75 83.75 190.9 9.008.210.329.2084.56192.0 7.617.810.329.3184.76190.09.668.50 1.5 27.84 82.11 190.0 7.127.721.529.0784.33191.7 7.447.791.529.2584.65191.59.588.45 3 27.78 82.00 190.5 7.147.63329.0984.36191.9 6.787.68329.1584.47190.79.488.42 3.5 27.77 81.99 190.0 6.967.55428.7583.75191.2 6.737.67429.1884.52190.79.698.46 628.4483.19191.8 6.847.70629.1284.42191.09.558.44 828.5083.30191.5 6.887.72828.8383.89190.88.368.19 1227.8682.15190.6 6.867.731227.6381.73191.96.607.64 1627.8082.04190.4 6.857.75 73 Table 38 (continued). Summer - TRM 490.5 LDB Mid-channel RDB Depth ûC °F Cond DOpHDepthûC°FCond DOpHDepthûC°FCondDOpH Downstream Transect 0.3 28.19 82.74 198.5 9.588.520.327.9082.22198.7 8.888.330.328.3282.98194.59.508.51 1.5 28.15 82.67 199.0 9.548.491.527.7281.90200.1 7.078.161.528.2982.92194.99.408.42 3 27.51 81.52 197.7 6.607.62327.6881.82200.2 7.748.03327.4381.37196.66.137.55 5 26.91 80.44 200.6 4.237.33427.3081.14200.5 5.757.624.527.1980.94198.15.177.42 7 26.91 80.44 199.5 4.317.36627.1980.94200.0 5.507.53 827.1580.87201.1 5.217.48 1027.0980.76200.7 5.047.45 1327.1180.80200.3 5.177.46 1727.1480.85200.1 5.377.47 Middle Transect 0.3 28.70 83.66 196.0 10.9n/a0.328.3883.08198.8 9.848.570.328.7483.73193.29.838.64 1.5 28.28 82.90 196.2 10.0n/a1.527.9082.22200.6 8.488.201.527.4481.39199.46.587.75 3 27.16 80.89 198.2 4.68n/a327.2581.05201.3 5.617.54327.2781.09200.45.887.55 5 27.09 80.76 197.3 4.37n/a527.1380.83200.9 4.977.45427.3481.21200.46.157.59 727.0280.64200.3 4.717.40627.1780.91200.85.507.44 927.0080.60200.7 4.627.38727.1980.94201.15.577.37 1126.9880.56200.5 4.567.40 Upstream Transect 0.3 28.71 83.68 197.8 10.48.660.328.1582.67200.6 8.308.150.328.0782.53200.06.158.12 1.5 28.49 83.28 197.9 9.928.551.527.8782.17200.0 7.777.971.527.8082.04200.16.247.89 3 27.70 81.86 197.0 6.007.79327.3681.25200.3 5.787.51327.4681.43199.67.937.49 427.2481.03200.5 5.217.42427.3781.27199.38.587.43 627.1880.92200.7 4.947.36 827.0880.74200.5 4.737.30 9.527.0780.73200.2 4.687.30 74 Table 38 (continued). Autumn - TRM 482 LDB Mid-channel RDB Depth ûC °F Cond DOpHDepthûC°FCond DOpHDepthûC°FCondDOpH Downstream Transect 0.3 22.43 72.37 184.5 7.457.490.322.9273.26183.7 7.577.480.322.4372.37184.47.497.54 1.5 22.42 72.36 184.3 7.417.471.522.8973.20183.7 7.487.471.522.1971.94184.77.487.49 2 22.38 72.28 184.0 7.427.44322.6372.73184.2 7.417.44322.1471.85185.17.377.47 522.5172.52184.6 7.387.43522.1271.82185.37.327.44 722.3572.23185.0 7.347.40 922.1871.92184.4 7.297.36 1121.7571.15184.8 7.297.33 1321.7071.06184.2 7.337.29 1521.6370.93183.7 7.297.25 Middle Transect 0.3 23.49 74.28 183.7 7.727.570.323.4674.23183.4 7.597.500.322.9773.35183.87.627.52 1.5 23.21 73.78 183.6 7.667.531.523.8975.00183.8 7.477.491.522.7172.88183.87.577.52 3 23.21 73.78 183.4 7.667.49322.9673.33183.8 7.457.47322.6572.77184.17.457.51 422.9273.26183.4 7.407.45422.5972.66183.97.747.46 622.8173.06183.9 7.337.44 822.4572.41183.5 7.347.39 1021.9971.58183.3 7.327.37 1221.7471.13182.9 7.317.33 1421.4170.54183.0 7.237.29 1621.3970.50183.1 7.157.23 Upstream Transect 0.3 23.75 74.75 183.8 7.497.490.323.8374.89183.7 7.427.490.323.4274.16183.59.668.50 1.5 23.46 74.23 183.5 7.397.511.523.5774.43183.3 7.377.481.523.2873.90183.49.588.45 3 22.97 73.35 183.9 7.337.48323.0373.45183.9 7.347.84323.0873.54183.69.488.42 4 22.69 72.84 184.0 7.307.47422.7172.88183.3 7.337.47 9.698.46 6 22.61 72.70 183.6 7.247.46622.4872.46183.3 7.317.46 9.558.44 8 22.38 72.28 184.2 7.127.44822.4472.39183.1 7.327.45 8.368.19 10 22.15 71.87 184.4 7.067.421022.3272.18183.9 7.277.43 6.607.64 12 22.17 71.91 184.1 7.067.391221.8971.40182.7 7.297.41 1421.5470.77182.8 7.247.38 1621.3570.43183.0 7.267.39 75 76 Table 38 (continued). Autumn - TRM 490.5 LDB Mid-channel RDB Depth ûC °F Cond DO pH Depth ûC °F Cond DO pH Depth ûC °F Cond DO pH Downstream Transect 0.3 21.23 70.21 182.7 7.687.540.321.2670.27182.9 7.677.550.321.2170.18182.67.827.58 1.5 21.23 70.21 182.7 7.667.521.521.2670.27183.0 7.627.561.521.2170.18182.87.827.56 2 21.22 70.20 182.6 7.667.54321.2670.27183.0 7.597.54321.2070.16186.77.847.55 421.2670.27183.0 7.557.53421.1970.14183.57.947.55 621.2570.25183.0 7.507.56 821.2470.23183.0 7.487.51 1021.2470.23182.6 7.467.59 1221.2370.21183.0 7.447.47 1421.2470.23183.0 7.377.44 1621.0369.85183.0 7.397.42 Middle Transect 0.3 21.09 69.96 191.6 7.817.570.321.3370.39187.0 7.687.540.321.3470.41182.77.677.52 1.5 21.09 69.96 182.7 7.797.571.521.3370.39182.0 7.657.501.521.3470.41182.87.667.57 3 21.10 69.98 180.7 7.757.55321.3270.38182.2 7.607.51321.3470.41187.77.657.51 5 21.20 70.16 181.7 7.757.48521.3770.47182.4 7.547.17421.3470.41182.77.597.54 721.2970.32181.1 7.507.45621.3370.39182.87.557.53 921.2770.29181.3 7.477.40821.3270.38182.87.447.50 1021.3170.36182.87.457.48 Upstream Transect 0.3 21.06 69.91 179.4 7.817.560.321.2070.16179.5 7.407.490.321.2970.32180.77.727.55 1.5 21.06 69.91 179.5 7.817.521.521.2070.16179.5 7.467.501.521.2870.30180.27.837.56 3 21.03 69.85 179.9 7.777.55321.2070.16180.0 7.457.50221.2270.20181.17.867.60 521.1970.14179.4 7.447.48 721.1970.14179.4 7.397.46 921.2570.25179.5 7.107.41

Figures

77 78 Figure 1. Vicinity map for Sequoyah Nuclear plant depicting Chickamauga and Watts Bar Dam locations and water supply intakes downstream of the plant thermal discharge 79 Figure 2. Site map for Sequoyah Nuclear plant showing condenser cooling water intake structure, skimmer wall, and NPDES-permitted discharge Outfall No. 101 Figure 3. Biological monitoring stations upstream of Sequoyah Nuclear Plant. 80 Biomonitoring Stations Upstream of Sequoyah Nuclear Plant

  • Electrofishing o Gill Netting e Plankton! Water Quality --Benthic Macroinvertebrate Transect __ Wildlife Observation Transect 81 Figure 4. Biological monitoring stations downstream of Sequoyah Nuclear Plant, including mixing zone and thermal plume from SQN CCW discharge. Biomonitoring Stations Downstream of Sequoyah Nuclear Plant
  • Electrofishing o Gill Netting o Planktonl Water Quality --Benthic Macroinvertebrate Transect --Wildlife Observation Transect DThermal Plume, Summer (0812512011) Thermal Plume, Autumn (0911412011)

Figure 5. Benthic and shoreline habitat transects within the fish community sampling area upstream and downstream of SQN. SAHI data were collected on the left and right descending banks at endpoints of each transect. 82 Transects for Shoreline Aquatic Habitat Index (SAHI) Upstream and Downstream of Sequoyah Nuclear Plant CCW Discharge --SAHI Transects Figure 6. Locations of water temperature monitoring stations used to compare water temperatures upstream of SQN intake and downstream of SQN discharge during October 2010 through November 2011. Station 14 was used for upstream ambient temperatures of the SQN intake and was located at TRM 490.4. Station 8 was used for temperatures downstream of SQN discharge and was located at TRM 483.4. 83 84 Figure 7. Substrate composition at ten equally spaced points per transect (1 and 2) across the Tennessee River downstream of SQN. *Water depth (ft) at each point is denoted. Transects 1 and 2 are the most downstream of the eight transects downstream of the SQN discharge.

Figure 8. Substrate composition at ten equally spaced points per transect (3 and 4) across the Tennessee River downstream of SQN. *Water depth (ft) at each point is denoted. 85 Figure 9. Substrate composition at ten equally spaced points per transect (5 and 6) across the Tennessee River downstream of SQN. *Water depth (ft) at each point is denoted. 86 Figure 10. Substrate composition at ten equally spaced points per transect (7 and 8) across the Tennessee River downstream of SQN. *Water depth (ft) at each point is denoted.87 Figure 11. Substrate composition at ten equally spaced points per transect (1 and 2) across the Tennessee River upstream of SQN. *Water depth (ft) at each point is denoted. Transects 1 and 2 are the most downstream of the eight transects upstream of the SQN discharge. 88 Figure 12. Substrate composition at ten equally spaced points per transect (3 and 4) across the Tennessee River upstream of SQN. *Water depth (ft) at each point is denoted. 89 Figure 13. Substrate composition at ten equally spaced points per transect (5 and 6) across the Tennessee River upstream of SQN. *Water depth (ft) at each point is denoted. 90 Figure 14. Substrate composition at ten equally spaced points per transect (7 and 8) across the Tennessee River upstream of SQN. *Water depth (ft) at each point is denoted.91 Figure 15. Number of indigenous fish species collected during RFAI samples downstream of SQN (TRM 482) during 1996 and 1999 through 2011. 3125282924252726262630232625051015 20 25303519961999 200020012002 2003 2004 2005 2006 2007 2008 2009 2010 2011#ofindigenousspeciesYearAvg=27 Figure 16. Number of indigenous fish species collected during RFAI samples upstream of SQN (TRM 490.5) during 1993 to 1997 and 1999 through 2011.30282927202823313029312930312728282705101520 25 30354019931994 1995 199619971999 2000 2001 2002 200320042005 2006 2007 200820092010 2011#ofindigenousspeciesYearAvg=28 92 01234STRM481.3ATRM481.3STRM483.4ATRM483.4STRM488.0STRM490.5ATRM490.5PercentofoverallsampleMayfliesCaddisfliesSnailsFigure 17. Proportions of selected benthic taxa from Ponar dredge sampling at locations upstream and downstream of SQN, summer and autumn 2011. 93 Figure 18. Mean phytoplankton densities (cells/ml) for samples collected August 25, 2011. Figure 19. Mean phytoplankton biovolume (µm3/ml) for samples collected August 25, 2011. Figure 20. Mean phytoplankton densities (cells/ml) for samples collected October 10, 2011.

Figure 21. Mean phytoplankton biovolume (µm3/ml) for samples collected October 10, 2011.050,000100,000150,000 200,000250,000300,000 350,000400,000TRM481.1TRM483.4TRM487.9TRM490.7PhytoplanktonDensity(cells/ml)SiteBacillariophytaChlorophytaChrysophytaCryptophytaCyanophytaEuglenophytaPyrrophyta0200,000400,000 600,000800,0001,000,0001,200,000 1,400,000 1,600,000TRM481.1TRM483.4TRM487.9TRM490.7Biovolume(µm3/ml)BacillariophytaChlorophytaChrysophytaCryptophytaCyanophytaEuglenophytaPyrrophyta0100200 300400500 600TRM481.1TRM483.4TRM487.9TRM490.7PhytoplanktonDensity(cells/ml)SiteBacillariophytaChlorophytaChrysophytaCryptophytaCyanophytaEuglenophytaPyrrophyta020,00040,00060,00080,000100,000120,000TRM481.1TRM483.4TRM487.9TRM490.7Biovolume(µm3/ml)BacillariophytaChlorophytaChrysophytaCryptophytaCyanophytaEuglenophytaPyrrophyta94 Figure 22. Mean chlorophyll a concentrations for samples collected August 25 and October 10, 2011.

Figure 23. Mean zooplankton densities (number/m3) for samples collected August 25, 2011. Figure 24. Mean zooplankton densities (number/m3) for samples collected October 10, 2011 126149.561075.502 46810 121416TRM481.2TRM483.4TRM487.9TRM490.7Chlorophyllaconcentration(µg/l)SiteAugust2011October201101,0002,0003,0004,000 5,000 6,000TRM481.2TRM483.4TRM487.9TRM490.7ZooplanktonDensity(No./m3)SiteRotiferaCopepodaCladocera05,00010,00015,000 20,00025,00030,000 35,000 40,000 45,000TRM481.1TRM483.4TRM487.9TRM490.7ZooplanktonDensity(No./m3)SiteRotiferaCopepodaCladocera95 0.7750.80.8250.850.8750.90.9250.950.975Bray-Curtis SimilarityT_487.9_8T_481.1_8T_483.4_8T_490.7_8 Figure 25. Dendrogram of phytoplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected August 25, 2011. Samples for each location are coded by river mile and month. (Coph. Corr = 0.89) 96 0.60.650.70.750.80.850.90.95Bray-Curtis SimilarityT_490.7_10T_483.4_10T_487.9_10T_481.1_10 Figure 26. Dendrogram of phytoplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected October 10, 2011. Samples for each location are coded by river mile and month. (Coph. Corr = 0.78) 97 0.640.680.720.760.80.840.880.920.96Bray-Curtis SimilarityT_483.3_8T_490.7_8 T_487.9_8T_481.1_8 Figure 27. Dendrogram of zooplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected August 25, 2011. Samples for each location are coded by river mile and month. (Coph. Corr = 0.87) 98 99 Figure 28. Dendrogram of zooplankton community (taxa density, log10+1) cluster analysis (average distance) based on Bray-Curtis distance matrix among samples collected October 10, 2011. Samples for each location are coded by river mile and month. (Coph. Corr = 0.78) 0.60.650.70.750.80.850.90.95Bray-Curtis SimilarityT_483.3_10T_487.9_10 T_490.7_10T_481.1_10 Figure 29. Average hourly discharge from Chickamauga, Watts Bar, Apalachia, and Ocoee #1 dams, August 23 through August 25, 2011 05,00010,00015,00020,000 25,00030,00035,000 40,00045,00050,00013579111315171921231357911131517192123135791113151719212308/23/201108/24/201108/25/2011Discharge(cfs)DateandHourChickamaugaWattsBarApalachiaandOcoee#1 Figure 30. Average hourly discharge from Chickamauga, Watts Bar, Apalachia, and Ocoee #1 dams, October 8 through October 10, 2011 05,00010,00015,00020,000 25,000 30,00035,00040,000 45,000 50,00013579111315171921231357911131517192123135791113151719212310/08/201110/09/201110/10/2011Discharge(cfs)DateandHourChickamaugaWattsBarApalachiaandOccoe#1100 010,00020,00030,000 40,000 50,000 60,000 70,000 80,000 90,000100,00010/111/112/11/12/13/14/15/16/17/18/19/110/111/1Discharge(cfs)Date2011DailyAverageFlowHistoricalDailyAverage19762010Figure 31. Total daily average releases (cubic feet per second) from Watts Bar, Apalachia, and Ocoee 1 dams, October 2010 through November 2011 and historic daily average flows averaged for the same period 1976 through 2010. 101 102 Figure 32. Daily average water temperatures (°F) at a depth of five feet, recorded upstream of SQN intake (Station 14) and downstream of SQN discharge (Station 8), October 2009 through November 2010. 010203040 50 607080 90100WaterTemperature(°F)DateDownstreamofSQNDischargeUpstreamofSQNIntakeTNStateThermalDischargeLimit(86.9°F)

April 19, 2013 Bradley M. Love, OPS 5N-SQN SEQUOY AH NUCLEAR PLANT (SQN)--RlVER SCHEDULING FOR LOW FLOW CONDITONS Part IlI.F.l.b. and Part IlI.F.l.c. of the current SQN National Pollutant Discharge Elimination System (NPDES) permit summarize requirements related to monitoring thermal compliance for Outfall 101, the plant diffuser discharge to the Tennessee River. In particular, in these parts of the permit, ranges for the daily average flow past SQN are defined wherein special field surveys are required to verify the adequacy of the plant ambient river temperature and the adequacy of the plant diffuser mixing zone. These ranges in flow are given both for river conditions characterized by unsteady flow and river conditions characterized by steady flow. The type of unsteady flows of concern is the type created by strong hydro peaking, sustained day after day with low daily average flows. Similarly, the type of steady flows of concern is the type created by continuous, unvarying hydro operation, again sustained day after day, but at daily average flows lower than those of concern for low flow hydro peaking. To verify compliance to these requirements for special field surveys, the NPDES permit specifies that river flow data shall be submitted with the application for re-issuance of the permit. The purpose of this memo is to provide these data. In general, in the current NPDES permit, the daily average river flows past SQN that trigger the need for special field surveys are as follows: No units in operation at SON: No field surveys required. One unit in operation at SQN: Field surveys required if the daily average flow past SQN drops below 3,000 cfs in steady hydro operation or below 6,500 cfs in unsteady/peaking operation. Two units in operation at SQN: Field surveys required if the daily average flow past SQN drops below 6,000 cfs in steady hydro operation or below 13,000 cfs in unsteady/peaking operation. The current TV A strategy for managing these requirements is to schedule the operation of Chickamauga Reservoir in a manner so that there is no need to perform these special surveys. Thus far, there has been no need to schedule daily average river flows past SQN at a level below the trigger for steady-related surveys. And thus far, when it has been necessary to schedule river flows at a level below the trigger for unsteady-related surveys, such has been accomplished by limiting hydro peaking at Chickamauga Dam and Watts Bar Dam.

Given in Attachment 1 is a plot showing the daily average flow past SQN for the period beginning March 1,2011 and ending March 31, 2013. This period spans the time from the effective date of the current NPDES permit through the most recent full month (as of the date of this memo). Based on the actual operation of SQN, also given are the trigger levels summarized above. As shown, within the period of record, the daily average flow past SQN never dropped below the steady trigger for special field surveys. The daily average flow past SQN dropped below the unsteady trigger only for single events in May 2011 and October 2011, and several events from April 2012 through July 2012. In these events, and as presented above, hydro peaking at Chickamauga Dam and Watts Bar Dam was limited to move Chickamauga Reservoir toward steady operation, providing a more predictable behavior of the SQN thermal effluent and precluding the need for special field surveys. In limiting peaking operations at Chickamauga Dam and Watts Bar Dam, restrIctIOns are provided in as much as such is feasible in consideration of TVA's responsibility for providing public safety, navigation, power supply, recreation, water supply, and water quality. Peaking operations are characterized by providing hydro releases only during those hours of the day wherein there is a large demand for power, with little or no releases made during off-peak hours. In peaking operations, hydro releases can be suspended for eight or more hours per day (i.e., zero flow), followed by a period of intense high flow, creating significant sloshing in Chickamauga Reservoir. In contrast, when peaking operations are limited, efforts are made to provide hydro releases around-the-clock. Furthermore, if a change in flow is needed, an attempt is made to implement such as a single step from one steady condition to another steady condition. In practice, it is not uncommon for a hydro unit to trip out of service, temporarily interrupting the flow. Incidents in the immediate vicinity of the dams also can cause interruptions (e.g., capsized boat). In such events, releases are usually resumed within a short period of time following the incident, and may require a short duration release at a higher flow to preserve the total volume of release required for that day. Short duration releases at a higher flow also are sometimes required in response to unexpected disturbances in the power system, such as a shortfall in power supply due to the unexpected trip of a large generating unit. For the same period of time as in Attachment 1, given in Attachment 2 is a plot of the hourly releases from Chickamauga Dam and Watts Bar Dam. Release patterns associated with hydro peaking are apparent, with hourly flows from each hydro plant regularly varying within a single day between 5,000 cfs or less and over 45,000 cfs. Periods of zero flow also are common, particularly at Chickamauga Dam. Given in Attachment 3 is the same plot as in Attachment 2, but showing only those periods containing special hydro operations in support of SQN (i.e., as prompted by the requirements of Part 1lI.F.1.b. and Part 1lI.F.I.c. of the SQN NPDES permit). Within the period of record, a total of 762 days, there were a total 77 days requiring special hydro operations in support of SQN. For these periods, the limitations on peaking operations are apparent, with flow variations far less than those shown in Attachment 1. Given in Attachment 4 is the same plot as Attachment 3, but showing only the period from April 2012 through July 2012, which contained most of the events with daily average river flows below the unsteady trigger of 13,000 cfs. As shown, peaking operations as describe above are absent. At Watts Bar Dam, there were no events where the flow had to be interrupted or where higher releases were required in response to a river or power system need. At Chickamauga Dam, there were four events where the flow was temporarily interrupted and three events where higher releases were required on a short term basis in response to river or power system needs.

In conclusion, by the operating strategy discussed above and by the data presented herein, SQN thus far has operated in compliance with the requirements of Part III.F.l.b. and Part III.F.l.c. of the current NPDES permit. TV A River Scheduling will continue to maintain notes in their special operations database in support of these requirements, as long as they are found in the NPDES permit. Furthermore, TVA River Scheduling is prepared to manage special field surveys if there is a need to operate Chickamauga Reservoir in a manner that necessitates such by the NPDES permit requirements. Please contact me if you have any questions regarding the contents of this memo. Technical Special st V -River Scheduling WT IOB-K PNH:JGP Attachments cc (Attachments): T. W. Barnett, WT IOC-K L. D. Bean, WT IOB-K J. H. Everett, WT IOC-K T. R. Markum, BR 4A-C EDMS Vault -Knoxville, WT CA -K

Attachment

1 Approximate Daily Average Flow Past SQN from March 1, 2011 through March 31, 2013 051015 202530 354045 50 5560Mar-11Apr-11May-11Jun-11Jul-11Aug-11Sep-11Oct-11Nov-11Dec-11Jan-12Feb-12Mar-12Apr-12May-12Jun-12Jul-12Aug-12Sep-12Oct-12Nov-12Dec-12Jan-13Feb-13Mar-13Approx Daily Avgerage River Flow Past SQN (1000 cfs)Approx daily average flow past SQNUnsteady trigger for special field surveysSteady trigger for special field surveysU1OutageU1TripU1OutageU1TripU2TripU2OutageU2Trip

Attachment

2 Hourly Releases from Chickamauga Dam and Watts Bar Dam from March 1, 2011 through March 31, 2013 051015 202530 354045 50 5560Mar-11Apr-11May-11Jun-11Jul-11Aug-11Sep-11Oct-11Nov-11Dec-11Jan-12Feb-12Mar-12Apr-12May-12Jun-12Jul-12Aug-12Sep-12Oct-12Nov-12Dec-12Jan-13Feb-13Mar-13Hourly Release (1000 cfs)Chickamauga DamWatts Bar Dam

Attachment

3 Hourly Releases from Chickamauga Dam and Watts Bar Dam for Periods Requiring Special Hydro Operations for SQN 051015 202530 354045 50 5560Mar-11Apr-11May-11Jun-11Jul-11Aug-11Sep-11Oct-11Nov-11Dec-11Jan-12Feb-12Mar-12Apr-12May-12Jun-12Jul-12Aug-12Sep-12Oct-12Nov-12Dec-12Jan-13Feb-13Mar-13Hourly Release (1000 cfs)Chickamauga DamWatts Bar Dam

Attachment

4 Hourly Releases from Chickamauga Dam and Watts Bar Dam for Periods Requiring Special Hydro Operations for SQN, April 2012 through July 2012 0510 15 20 25 30 35 40 455055 60Apr-12May-12Jun-12Jul-12Hourly Releases (1000 cfs)Chickamauga DamWatts Bar Dam March 5, 2013 Bradley M. Love, OPS 5N-SON SEOUOYAH NUCLEAR PLANT UPDATE OF FLOWRATE CHARACTERISTICS THROUGH THE DIFFUSERS Part III, Section G of the current Sequoyah Nuclear Plant (SON) National Pollutant Discharge Elimination System (NPDES) permit states that: "The permittee shall calibrate the flowrate characteristics through the diffusers on a schedule of at least once every two years." In fulfillment of this requirement, a test of the flowrate characteristics through the diffusers was conducted on November 16, 2012. Plant conditions for the test included the operation of three Condenser Cooling Water pumps and three Essential Raw Cooling Water pumps. In the test, the flowrate through the diffusers was determined based on measurements of water velocities in the diffuser pond using an acoustic doppler current profiler. Measurements for the diffuser head were made using the stage recorders belonging to the SON Environmental Data Station. All instruments were certified prior to the test. The results of the measurements, which include a summary of all tests since 1986, are provided in Attachment 1. The rating curve for computing the diffuser flowrate has been updated based on the new information and is provided in Attachment 2. With the updated curve, the mean-square error between the computed and measured diffuser flowrates is about 6.5 percent. This error falls within the +/-1 0 percent standard given by the NPDES inspection manual and demonstrates that the hydraulic characteristics of the diffusers continue to provide a good method to estimate the discharge from SON to the Tennessee River. The updated rating curve will be incorporated into the compliance model for Outfall 101. If you have any questions regarding this work, please call me at (423) 632-2881. /Paul N. Hopping Technical Speci ist River Scheduling WT 10B-K PNH:JGP Attachments cc (Attachments): Matthew T. Boyington, WT 10B-K Kelie H. Hammond, WT 10C-K Gary D. Lucas, WT 10B-K Travis R. Markum, BR 4A-C Robert D. Stone, MP 5G-C EDMS, WT 10C-K

Attachment

1 Calibration Data for SQN Diffuser Discharge, 1986 -2012 Field Measurements Number Test Of Water Surface Elevation (Bl Diffuser Diffuser Discharge Pumps Diffuser Head Discharge Date Measurement River Method (Al Pond H Q CCW ERCW (feet MSL) (feet MSL) (feet) (cfs) 12118/1986 2 4 MM 678.03 677.00 1.03 889 12117/1986 3 4 MM 678.46 676.90 1.56 1,297 12/18/1986 4 4 MM 680.41 676.90 3.51 1,686 12119/1986 6 4 MM 683.53 677.17 6.36 2,490 03128/1989 5 4 MM 680.80 676.46 4.34 2,015 03/29/1989 5 4 MM 680.82 676.35 4.47 2,161 03/22/1990 2 3 MM 678.44 677.27 1.17 943 04/05/1990 3 4 MM 680.57 678.54 2.03 1,470 10105/1990 3 4 MM 682.30 680.20 2.10 1,457 12/19/1990 6 4 MM 682.54 676.26 6.28 2,350 04103/1991 6 4 MM 684.20 678.18 6.02 2,511 05/22/1991 6 4 MM 688.70 682.60 6.10 2,451 12/10/1991 5 4 MM 682.70 677.90 4.80 2,213 04/10/1992 2 3 MM 680.13 679.12 1.01 879 02/18/1994 "} 2 3 MM 679.42 678.13 1.29 871 06/14/1994 6 4 MM 688.50 682.00 6.50 2,507 04/03/1997 'U} 3 3 MM 679.50 677.30 2.20 1,223 05/23/1997 6 3 MM 688.40 681.80 6.60 2,551 05/06/1998 6 3 ADCP 688.20 681.70 6.50 2,345 05/11/1999 6 3 ADCP 689.20 682.60 6.60 2,274 10/10/2001 6 3 ADCP 687.10 680.30 6.80 2,359 07/272002 6 4 ADCP 689.40 682.40 7.00 2,759 04/23/2003 ,., 3 4 ADCP 684.05 682.20 1.85 1,552 03/07/2006 6 3 ADCP 682.06 675.97 6.09 2,511 11/04/2007 3 4 ADCP 680.88 678.66 2.22 1,291 11117/2009 3 3 ADCP 679.71 677.67 2.04 1350 12/17/2009 6 3 ADCP 683.29 677.15 6.14 2354 01/03/2011 6 3 ADCP 686.08 678.90 7.18 2360 11/16/2012 3 3 ADCP 681.08 678.62 2.46 1299 Notes: (A) MM=Marsh.McBirney instrumentation. ADCP=AcQustic Doppler Current Profiler instrumentation. (8) Water surface elevations for the diffuser pond and river recorded by instrumentation of the SQN Environmental Data Station. MSL=Mean Sea Level. (C) The test of 02118/94 was performed with very windy conditions, making it difficult to keep the boat steady. Due to the potential error introduced by these conditions, the resulting measurement was not used to dctennine the head-discharge relationship for the diffuser discharge. (D) The test of 04103/97 included a malfunction of the Marsh-McBimey compass, which prohibited the collection of data for flow direction. The diffuser discharge is based on an assumed flow direction. Due to the potential error introduced by these conditions, the resulting measurement was not used to determine the head-discharge relationship for the diffuser discharge. (E) The test of 04/23/03 was performed with an ADCP setting that likely overestimated the volume of water passing through the diffuser pond. The resulting discharge significantly exceeded the capacity of pumps in service at the time. Due to the potential error introduced by these conditions, the resulting measurement was not used to determine the head-discharge relationship for the diffuser discharge.

Attachment

2 Rating Curve for SQN Diffuser Discharge 9 8 7 _ 6 -Q) .! -J: 5 "C ca Q) J: 4 Q) III 3 c 2 1 2012 Rating Curve Computation :' / Q= CAHII2, where: // C/Co = 0.8949+0.4697 (HlHo)-1.201 0(HlHo)'+1.6581(HlHo)'-1.0888H1Ho)'+0.2584(HlHo)'. for HlHo < 1.0 .. / -C/Co = 0.9913. for HlHo > 1.0 / / Co = 3.736 cfsffeel"'; Ho = 6 feet; A =259.6 feet' l,l' , .. ,/ H = Difference in elevation between the water surface in the diffuser pond (EDS Station 12) and the water : .. ".' surface in the river (EDS Station 13). ./0 : :' 0 / .'1' ,..//0 ,:' h .,/' .// ....... ,/ . : " ......... / .... /. 00 ..... D ... ** .... .... -10% / .... /" y:' ....... ... ,,/ ......... .' 0***** .... v/ .' "" ......... / ..... " .... ... 'O'. -Rating Curve .,/ .. ..0 . ...,;,-0:: ..... ... 0 Field Measurements .. -... Note: Rating curve valid only for ___ .-.;;;;ii diffuser head below about 8 feet. 0 o 500 1000 1500 2000 2500 3000 Diffuser Discharge, Q (cfs)

TENNESSEE VALLEY AUTHORITY River Operations & Renewable

Study to Confirm the Calibration of the Numerical Model for the Thermal Discharge from Sequoyah Nuclear Plant as Required by NPDES Permit No. TN0026450 of March 2011

WR2013-1-45-152

Prepared by T. Matthew Boyington Paul N. Hopping Walter L. Harper

Knoxville, Tennessee

April 2013 i EXECUTIVE SUMMARY The National Pollutant Discharge Elimination System (NPDES) permit for Sequoyah Nuclear Plant (SQN) identifies the release of cooling water to the Tennessee River through the plant discharge diffusers as Outfall 101. The primary method to monitor compliance with the NPDES temperature limits for this outfall includes the use of a numerical model that solves a set of governing equations for the hydrothermal conditions produced in the river by the interaction of the SQN release and the river discharge. The numerical model operates in real-time and utilizes a combination of measured and computed values for the temperature, flow, and stage in the river; and the temperature and flow from the SQN discharge diffusers. Part III, Section G of the permit states: The numerical model used to determine compliance with the temperature requirements for Outfall 101 shall be subject of a calibration study once during the permit cycle. The study should be accomplished in time for data to be available for the next permit application for re-issuance of the permit. A report of the study will be presented to the division of Water Pollution Control. This report is provided in fulfillment of these requirements.

The basic formulation of the numerical model is presented herein. Three empirical parameters are used to calibrate the model. The first is the effective width of the diffuser slot, and the second is a relationship used to compute the entrainment of ambient water along the trajectory of the plume. The third parameter is a relationship for the amount of diffuser effluent that is re-entrained into the diffuser plume for periods of sustained low river flow.

Temperature measurements across the downstream end of the SQN mixing zone from fifty samples collected between 1982 and 2012 were used in this calibration study. These observed data were compared with computed downstream temperatures from the numerical model for the same periods of time. In this process, sensitivity tests were performed for the effective diffuser slot width, entrainment relationship, and plume re-entrainment function. The results show acceptable agreement between computed and measured temperatures, particularly at river temperatures greater than 75ºF. The overall average discrepancy between the measured and computed downstream temperatures was about 0.55 Fº (0.31 Cº). For downstream temperatures above 75ºF, the average discrepancy was about 0.38 Fº (0.21 Cº). There was no significant change in the model performance compared to the previous calibration, and as a result, no update was required in the model parameter set.

ii CONTENTS Page EXECUTIVE SUMMARY ............................................................................................................. iLIST OF FIGURES ....................................................................................................................... iiiLIST OF TABLES ......................................................................................................................... iiiINTRODUCTION .......................................................................................................................... 1BACKGROUND ............................................................................................................................ 3NUMERICAL MODEL .................................................................................................................. 7Plume Entrainment ........................................................................................................... 12Diffuser Effluent Re-Entrainment ..................................................................................... 13CALIBRATION ........................................................................................................................... 13Previous Calibration Data and Calibration Work ................................................................... 13New Calibration Data and Calibration Work .......................................................................... 16Diffuser Slot Width ............................................................................................................ 16Plume Entrainment Coefficient ......................................................................................... 16Diffuser Effluent Re-Entrainment ..................................................................................... 18Results of Updated Calibration ........................................................................................ 20CONCLUSIONS........................................................................................................................... 23REFERENCES ............................................................................................................................. 24 iii LIST OF FIGURES Page Figure 1. Location of Sequoyah Nuclear Plant .............................................................................. 1Figure 2. Chickamauga Reservoir in the Vicinity of Sequoyah Nuclear Plant ............................. 2Figure 3. Locations of Instream Temperature Monitors for Sequoyah Nuclear Plant ................... 6Figure 4. Sequoyah Nuclear Plant Outfall 101 Discharge Diffusers ............................................. 7Figure 5. Two-Dimensional Plane Buoyant Jet Model for a Submerged Diffuser ........................ 8Figure 6. Sensitivity of Computed Temperature Td to Diffuser Effective Slot Width ................ 17Figure 7. Sensitivity of Computed Temperature Td to Plume Entrainment Coefficient .............. 18Figure 8. Sensitivity of Computed Temperature Td to Effluent Re-Entrainment Function ......... 19Figure 9. Comparison of Computed and Measured Temperatures Td for Field Studies from April 1982 through November 2012 ...................................................................21Figure 10. Comparison of Computed and Measured 24-hour Average Temperatures Td for Station 8 for 2010 .................................................................................................21Figure 11. Comparison of Computed and Measured Hourly Average Temperatures Td for Station 8 for 2010 ................................................................................................22 LIST OF TABLES Table 1. Summary of SQN Instream Thermal Limits for Outfall 101 ........................................... 5Table 2. Thermal Surveys at SQN from April 1982 through March 1983 .................................. 14Table 3. Thermal Surveys at SQN from March 1996 through April 2003 .................................. 15Table 4. Thermal Surveys at SQN from February 2004 through November 2007 ...................... 15Table 5. Thermal Surveys at SQN from November 2012 ........................................................... 16Table 6. Plume Re-Entrainment Iteration Numbers and Factors ................................................. 19 1 INTRODUCTION The Sequoyah Nuclear Plant (SQN) is located on the right bank of Chickamauga Reservoir at Tennessee River Mile (TRM) 484.5. As shown in Figure 1, the plant is northeast of Chattanooga, Tennessee, about 13.5 miles upstream and 45.4 miles downstream of Chickamauga Dam and Watts Bar Dam, respectively. As shown in Figure 2, the reservoir in the vicinity of SQN contains a deep main channel with adjacent overbanks and embayments. The main channel is approximately 900 feet wide and 50 to 60 feet deep, depending on the pool elevation in Chickamauga Reservoir. The overbanks are highly irregular and usually less than 20 feet deep.

SQN has two units with a total summertime gross generating capacity of about 2350 MWe and an associated waste heat load of about 15.6x109 Btu/hr (TVA, 2010). The heat transferred from the steam condensers to the cooling water is dissipated to the atmosphere by two natural draft cooling towers, to the river by a two-leg submerged multiport diffuser, or by a combination of both. The release to the river is identified in the National Pollutant Discharge Elimination System (NPDES) Permit as Outfall 101. Figure 1. Location of Sequoyah Nuclear Plant 2 Figure 2. Chickamauga Reservoir in the Vicinity of Sequoyah Nuclear Plant f/llllllm Denotes Reservoir areas of water depth less than 20 feet Mixing Zone 3 The compliance of SQN operation with the instream temperature limits specified in the NPDES permit (TDEC, 2011) is based on a downstream temperature that is calculated on a real-time basis by a numerical computer model. Part III, Section G of the permit states: The numerical model used to determine compliance with the temperature requirements for Outfall 101 shall be subject of a calibration study once during the permit cycle. The study should be accomplished in time for data to be available for the next permit application for re-issuance of the permit. A report of the study will be presented to the Division of Water Pollution Control. Any adjustments to the numerical model to improve its accuracy will not need separate approval from the Division of Water Pollution Control; however, the Division will be notified when such adjustments are made. This report presents a summary of compliance model and the required calibration study.

BACKGROUND The original method of monitoring thermal compliance for the SQN diffuser discharge (i.e., Outfall 101), included two temperature stations located near the downstream corners of the mixing zone, Station 8 and Station 11 (see Figure 2). Because of the necessity to keep the navigation channel free of obstructions, temperature stations could not be situated between these locations to monitor the center of the thermal plume. The upstream ambient river temperature was measured at Station 13, located on the plant intake skimmer wall. In August 1983, the Tennessee Valley Authority (TVA) reported the results of six field studies of the SQN diffuser performance under various river and plant operating conditions (TVA, 1983a). The data summarized in the report showed that based on measured temperature variations across the downstream edge of the mixing zone, Station 8 and Station 11 were inadequate in providing a representative cross-sectional average temperature of the thermal plume. In particular, it was found that Station 11 often was not in the main path of flow of the thermal plume and did not always show elevated temperatures. The remaining downstream monitor, Station 8, also was not considered adequate because it again was located outside the navigation channel. In the report, TVA proposed an alternate method to monitor thermal compliance involving the use of a numerical model to simulate the behavior of the thermal plume in the mixing zone. The model would provide a real-time assessment of compliance with the thermal discharge limitations. Information required for the model included: the ambient river temperature upstream of the diffuser mixing zone (measured at Station 13, see Figure 2), the discharge in the river at SQN (determined from measurements at Watts Bar Dam and Chickamauga Dam), the depth of flow in the river (measured at Station 13), the temperature of the flow issuing from the plant diffusers (measured at Station 12, see Figure 2), and the discharge of the flow issuing from the diffusers (determined from measurements at both Station 12 and Station 13). A PC, located in the SQN Environmental Data Station (EDS), was to be used collect the required data, compute the thermal compliance parameters, and distribute the results to plant operators (see TVA, 1983b). The August 1983 report presented results demonstrating the validity of using the numerical model for tracking compliance with the Outfall 101 thermal limitations.

4 The method of using the numerical model was sent to the Environmental Protection Agency (EPA) and the Tennessee Department of Environment and Conservation (TDEC), requesting approval for implementation as a valid means for monitoring SQN thermal compliance. The key advantage of the method includes a representation of the cross-sectional average downstream temperature that is at least as good as the instream temperature measurements from Station 8 and Station 11. The method also provides consistency with procedures that are used for scheduling releases from Watts Bar Dam and Chickamauga Dam, as well as procedures for operating Sequoyah Nuclear Plant. This consistency helps TVA minimize unexpected events that can potentially threaten the NPDES thermal limits for Outfall 101. In March 1984 approval was granted for TVA to use the numerical model as the primary method to track thermal compliance. Except for infrequent outages, the model has been in use ever since. Subsequently, Station 11 was removed from the river. However, Station 8 was retained to provide an optional method to track thermal compliance should there be a need to remove the model from service. Due to the ever changing understanding of the hydrothermal aspects of Chickamauga Reservoir, as well as the operational aspects of the nuclear plant and river system, modifications have been necessary over the years for both the numerical model and thermal criteria for Outfall 101. The current version of the model is presented in more detail later. The current thermal criteria are presented in Table 1. The limit for the temperature at the downstream end of the mixing zone (Td) is a 24-hour average value of 86.9°F (30.5°C) and an hourly average value of 93.0°F (33.9°C). The instream temperature rise (T) is limited to a 24-hour average of 5.4 F° (3.0 Cº) for months April through October, and 9.0 F° (5.0 Cº) for months November through March. The latter "wintertime" limit was obtained by a 316(a) variance. The temperature rate-of-change at the downstream end of the mixing zone (dTd/dt) is limited to 3.6 F°/hr (2 Cº/hr). With the compliance model, dTd/dt is based on 24-hour average river conditions and 15 minute plant conditions. Other details related to the temperature limits for Outfall 101 are provided in the notes accompanying Table 1. It is important to note that compliance with instream temperature limits are based on a computed downstream temperature at a depth of 5.0 feet. And in a similar fashion, the upstream temperature is measured at the 5.0 foot depth, based on the average of temperature readings at the 3-foot, 5-foot and 7-foor depths.

Originally, the ambient river temperature for the temperature rise was measured at Station 13, about 1.1 miles upstream of the discharge diffusers. However, under sustained low flow conditions, it was discovered that heat from the diffusers can migrate upstream and reach the area of Station 13. In this manner, the ambient temperature can become elevated, thereby artificially reducing the measured impact of the plant on the river (i.e., T). As such, in late March 2006, a new ambient temperature station was installed in the river further upstream at TRM 490.4, about 6.8 miles upstream of the diffusers. The location of the new monitor, entitled Station 14, is shown in Figure 3.

5 Table 1. Summary of SQN Instream Thermal Limits for Outfall 101 Type of Limit Averaging (hours) NPDES Limit2 Max Downstream Temperature, Td 24 86.9°F (30.5°C) Max Downstream Temperature, Td 1 93.0°F (33.9°C) Max Temperature Rise, T 24 5.4 F°/9.0 F° (3.0 Cº/5.0 Cº) Max Temperature Rate-of-Change, dTd/dt Mixed 3.6 F°/hr (2 Cº/hr) Notes: 1. Compliance with the river limitations (river temperature, temperature rise, and rate of temperature change) shall be monitored by means of a numerical model that solves the thermohydrodynamic equations governing the flow and thermal conditions in the reservoir. This numerical model will utilize measured values of the upstream temperature profile and river stage; flow, temperature and performance characteristics of the diffuser discharge; and river flow as determined from releases at the Watts Bar and Chickamauga Dams. In the event that the modeling system described here is out of service, an alternate method will be employed to measure water temperatures at least one time per day and verify compliance of the maximum river temperature and maximum temperature rise. Depth average measurements can be taken at a downstream backup temperature monitor at the downstream end of the diffuser mixing zone (left bank Tennessee River mile 483.4) or by grab sampling from boats. Boat sampling will include average 5-foot depth measurements (average of 3, 5, and 7-foot depths). Sampling from a boat shall be made outside the skimmer wall (ambient temperature) and at quarter points and mid-channel at downstream Tennessee River mile 483.4 (downstream temperature). The downstream reported value will be a depth (3, 5, and 7-foot) and lateral (quarter points and midpoint) average of the instream measurements. Monitoring in the alternative mode using boat sampling shall not be required when unsafe boating conditions occur. 2. Compliance with river temperature, temperature rise, and rate of temperature change limitations shall be applicable at the edge of a mixing zone which shall not exceed the following dimensions: (1) a maximum length of 1500 feet downstream of the diffusers, (2) a maximum width of 750 feet, and (3) a maximum length of 275 feet upstream of the diffusers. The depth of the mixing zone measured from the surface varies linearly from the surface 275 feet upstream of the diffusers to the top of the diffuser pipes and extends to the bottom downstream of the diffusers. When the plant is operated in closed mode, the mixing zone shall also include the area of the intake forebay. 3. Information required by the numerical model and evaluations for the river temperature, temperature rise, and rate of temperature change shall be made every 15 minutes. The ambient temperature shall be determined at the 5-foot depth as the average of measurements at depths 3 feet, 5 feet, and 7 feet. The river temperature at the downstream end of the mixing zone shall be determined as that computed by the numerical model at a depth of 5 feet. 4. Daily maximum temperatures for the ambient temperature, the river temperature at the downstream edge of the mixing zone, and temperature rise shall be determined from 24-hour average values. The 24-hour average values shall be calculated every 15 minutes using the current and previous ninety-six 15-minute values, thus creating a 'rolling' average. The maximum of the ninety-six observations generated per day by this procedure shall be reported as the daily maximum value. For the river temperature at the downstream end of the mixing zone, the 1-hour average shall also be determined. The 1-hour average values shall be calculated every 15 minutes using the average of the current and previous four 15-minute values, again creating a rolling average. 5. The daily maximum 24-hour average river temperature is limited to 86.9°F (30.5°C). Since the state's criteria makes exception for exceeding the value as a result of natural conditions, when the 24-hour average ambient temperature exceeds 84.9°F (29.4°C) and the plant is operated in helper mode, the maximum temperature may exceed 86.9°F (30.5°C). In no case shall the plant discharge cause the 1-hour average downstream river temperature at the downstream of the mixing zone to exceed 93.0°F (33.9°C) without the consent of the permitting authority. 6. The temperature rise is the difference between the 24-hour average ambient river temperature measured at Station 14 and the computed 24-hour average temperature at the downstream end of the mixing zone. The 24-hour average temperature rise shall be limited to 5.4F° (3.0 C°) during the months of April through October. The 24-hour average temperature rise shall be limited to 9.0F° (5.0 C°) during the months of November through March. 7. The rate of temperature change shall be computed at 15-minute intervals based on the current 24-hour average ambient river temperature, current 24-hour-hour average river flow, and current values of the flow and temperature of water discharging through the diffuser pipes. The 1-hour average rate of temperature change shall be calculated every 15-minutes by averaging the current and previous four 15-minute values. The 1-hour average rate of temperature change shall be limited to 3.6F° (2 C°) per hour.

6 Figure 3. Locations of Instream Temperature Monitors for Sequoyah Nuclear Plant SQNSta 8, TRM 483.4Mixing ZoneDiffusersSta 12Sta 13, TRM 484.7T = Td-TuTuSta 14, TRM 490.4TddTd/dtChickamauga ReservoirTennessee RiverSoddyCreekOpossumCreekDaily average flowIntake 7 NUMERICAL MODEL The diffusers at SQN are located on the bottom of the navigation channel in Chickamauga Reservoir. As shown in Figure 4, each diffuser is 350 feet long, and contains seventeen 2-inch diameter ports per linear foot of pipe, arranged in rows over an arc of approximately 18 degrees in the downstream upper quadrant of the diffuser conduit. The two diffuser legs rest on an elevated pad approximately 10 feet above the bottom of the river, occupying the 700 feet of navigation channel on the plant-side of the river (right side of the channel, looking downstream). The flow in the immediate vicinity of the ports is far too complex to be analyzed on a real-time basis with current computer technology. Therefore, a simplifying assumption is made that the diffusers can be treated as a slot jet with a length equal to that of the perforated sections of the pipe. The width of this assumed slot is one of three empirical parameters used to calibrate the model. The second is a relationship used to compute the entrainment of ambient water along the trajectory of the plume and the third is a relationship for the amount of diffuser effluent that is re-entrained into the diffuser plume for sustained low river flow.

The initial development of the numerical model is described in detail by Benton (2003). Based on later studies that provided evidence that re-entrainment occurs (TVA, 2009), the original numerical model was modified to better reflect the local buildup of heat that occurs in the river under such conditions. Before presenting calibration results, it is appropriate first to provide a brief description of the model formulation. Figure 4. Sequoyah Nuclear Plant Outfall 101 Discharge Diffusers 8 In general, the model treats the effluent discharge from the diffusers as a fully mixed, plane buoyant jet with a two-dimensional (vertical and longitudinal) trajectory. This is shown schematically in Figure 5. The jet discharges into a temperature-stratified, uniform-velocity flow and entrains ambient fluid as it evolves along its trajectory. The width, b, of the jet and the dilution of the effluent heat energy increase along the jet trajectory, decreasing the bulk mixed temperature along its path. Figure 5. Two-Dimensional Plane Buoyant Jet Model for a Submerged Diffuser Consideration of the mass, momentum, and energy for a cross section of the plume orthogonal to the jet trajectory and having a differential thickness ds, yields the following system of ordinary differential equations, ejjmbvdsd (conservation of mass in jet), (1) eejjumbuvdsd (conservation of x momentum in jet), (2) jeeejjbgvmbvvdsd (conservation of y momentum in jet), (3) eejjjcTmbcTvdsd (conservation of thermal energy in jet), (4) jvudsdx, and (5) jvvdsdy, (velocity of jet tangent to trajectory). (6) uriver(y) = ueyxsb(s)Triver(y)Ruvjv 9 The following auxiliary relationships also are needed to solve the differential equations, 2/122vuumeee, (7) jwaterjT, (8) ewatereT, (9) yTTrivere, (10) rivereuu, (11) 0ev, and (12) 2/122vuvj. (13) In these equations, the subscripts j and e denote conditions within the buoyant jet and conditions within the water upstream of the mixing zone that is entrained by the jet, respectively. Thus, j denotes the density of water at a point inside the jet and e denotes the density of water entrained from upstream of the mixing zone. Te denotes the temperature of the water upstream of the mixing zone that is entrained by the jet. The x-velocity of the entrained water, ue, is the same as the river velocity, uriver, which is negligible in the vertical direction (i.e., ve = 0). The magnitude of the velocity along the jet trajectory is denoted by vj, with x- and y-components u and v, respectively. The individual jets issuing from the array of 2-inch diameter outlet ports of each diffuser are modeled as a plane jet issuing from a slot of width b0. Ideally, the slot width is chosen to preserve the total momentum flux issuing from the circular ports of the diffuser. However, as indicated earlier, for this formulation, the slot width is used as a term to calibrate the numerical model. The river velocity uriver is computed by a one-dimensional unsteady flow model of Chickamauga Reservoir. Apart from information for the reservoir geometry, the basic input for the flow model includes the measured hydro releases at Watts Bar Dam and Chickamauga Hydro Dam and the measured river water surface elevation at SQN.

The transverse gradients of velocity, temperature, and density that occur within the jet due to turbulent diffusion of the effluent momentum and energy are modeled as an entrainment mass flux, me, induced by the vectorial difference between the velocity of the jet and that of the river flow upstream of the mixing zone. Empirical relationships for the entrainment coefficient are based on arguments of jet self-similarity and asymptotic behavior. These relationships incorporate non-dimensional parameters, such as a Richardson or densimetric Froude number, that describe the relative strengths of buoyancy and momentum flux in the jet (e.g., see Fischer et al., 1979). Again, as indicated earlier, the entrainment coefficient, like the slot width, is adjusted as part of the calibration process.

10 The initial conditions required by the model include, 00bbss, (14) cos0Rxss, (15) sin0Ryss, (16) cos000bquss, (17) sin000bqvss, and (18) 00TTssj. (19) This system of differential equations, auxiliary equations, and initial conditions comprise a first-order, initial-value problem that can be integrated from the diffuser slot outlet (s = s0) to any point along the plume trajectory. Note in the above that R is the radius of the diffuser conduit, b0 is the effective width of the diffuser slot, is the exit angle of the diffuser jet, T0 is the temperature of effluent issuing from the slot, and q0 is the effluent discharge per unit length of diffuser. In practice, integration of the governing equations is halted when the jet centerline reaches a point five feet below the water surface (the regulatory compliance depth) or when the upper boundary of the jet reaches the water surface. The jet temperature, Tj, at this point is reported as the fully-mixed temperature to which the thermal regulatory criteria are applied or to which monitoring station data at the edge of the regulatory mixing zone are compared. The integration is done with an adaptive step-size, fourth-order Runge-Kutta algorithm.

In the model, Station 13 (Figure 2), located 1.1 miles upstream of the diffusers, is used to represent the temperature of the water entrained in the mixing zone, yTTrivere. Whereas this is a good assumption for river flows where the effluent plume is carried downstream, it weakens for low river flows. Based on the understanding gained in recent studies (TVA, 2009), it is known that partial re-entrainment of the effluent plume occurs at sustained low river flow, increasing the temperature of the water entering the mixing zone above that represented by Station 13. To simulate this phenomenon, the model modifies the Station 13 temperature profile for low river flows. For each point in the profile, a local densimetric Froude number is computed as bZZgeeperiverruF, (20) 11 where uriver is the average river velocity, Ze-Zb is the elevation of the profile point relative to the bottom elevation of the river, e is the entrainment water density at that elevation, and p is the density of the effluent plume at the 5-foot compliance depth. The densimetric Froude number represents the ratio of momentum forces to buoyancy forces in the river flow. If Fr is less than 1.0 (i.e., buoyancy greater than momentum), it is assumed that the buoyancy of the plume is sufficient to cause part of the plume to travel upstream and become re-entrained into the flow, thereby increasing the temperature of the water entering the mixing zone. The modified entrainment temperature NeT at each point in the Station 13 profile is computed by repeatedly evaluating 1nepneTR1.0TRT (21) for values of n from 1 to N, where N is the number of iterations of Eq. (21), R is a re-entrainment fraction, 0neT is the original Station 13 temperature, and Tp is the computed plume temperature at the 5-foot depth. N and R are functions of the 24-hour average river velocity. After new Station 13 temperatures have been computed for the entire profile, the mixing zone computation is performed again, using the modified profile to get a new plume temperature at the 5-foot depth. It is emphasized that the final result of the model is the computed temperature at the downstream end of the mixing zone. The instream temperature rise is still computed based on the temperature measurement at the new ambient temperature monitor, Station 14.

Values for N and R are calibrated based on observed temperatures at the downstream end of the diffuser mixing zone for low river flow conditions, as indicated earlier. Depending on the river stage, the modifications by Equation 21 begin to take effect as the 24-hour average river flow drops through the range of 17,000 cfs to 25,000 cfs, and increases as the 24-hour average river flow continues to drop. For river flows above this range, no modification is needed for re-entrainment.

The downstream temperature and instream temperature rise provided by the model are computed every 15 minutes, using instantaneous values of the measured diffuser discharge temperature (Station 12), measured upstream temperature profile (Station 13), measured ambient temperature (Station 14), measured river elevation (Station 13), and computed values of the river velocity (one-dimensional unsteady flow model of Chickamauga Reservoir) and diffuser discharge. The diffuser discharge is computed based on the difference in water elevation between the SQN diffuser pond (Station 12) and the river (Station 13). All computations are performed every 15 minutes to provide rolling hourly and 24-hour average values. The hourly averages are based on the current and previous four 15-minute values, whereas the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> averages are based on current and previous ninety-six 15-minute values. The temperature rate-of-change is determined slightly different, being computed every 15 minutes based on current 24-hour average river conditions and current 15-minute values of the flow and temperature of water discharging from the SQN diffusers. This method was adopted in August 2001 in order to distinguish between rate-of-change events due to changes in SQN operations (i.e. changes in plant discharge flow and/or temperature) and those due to non-SQN changes in operations (e.g., changes in river flow). Prior to this change, SQN was held accountable for temperature rate-of-change events over which it had very little control or influence.

12 Plume Entrainment Two empirical relationships for the plume entrainment coefficient are available in the numerical model. The first, developed by McIntosh, was inferred from a relationship for the entrainment coefficient determined from the data reported in 1983 (TVA, 1983a) and is given by 00.155.000.175.027.0dd2.5ddF for F0.75 for F0.27F for , (22) where Fd is the densimetric Froude number of the diffuser discharge defined by oododdgbwF. (23)

The term wd is the velocity of the diffuser discharge, g is the gravitational constant, b0 is the diffuser slot width, d is the density of the diffuser discharge, and o is the density of the ambient river water at the discharge depth.

The second entrainment coefficient, based on laboratory data, was originally developed by Benton in 1986 and is given by 20584254361691310.rmf.tanh.., (24) where b/urmfriver3, (25) and odolgQb0. (26) Term uriver is the ambient river velocity, as previously defined, Q0 is the diffuser discharge flowrate, and l is the length of the ported section of the diffuser.

13 Diffuser Effluent Re-Entrainment Partial re-entrainment of the diffuser plume is known to occur under conditions of low river flow. When the diffuser plume attempts to entrain an amount of ambient flow greater than what is available from further upstream, the upper portions of the plume tend to migrate upstream and plunge downward to be mixed with the flow in the lower portion of the river. The formulation to simulate this phenomenon was presented earlier (Eqs. 20 and 21). The unknown coefficients to be determined in the calibration process are the number of iterations N and re-entrainment fraction R in Eq. (21), which are functions of the 24-hour average river velocity. CALIBRATION The numerical model is calibrated to achieve the best match between computed downstream temperatures and field measurements at the downstream end of the mixing zone. Field measurements at the downstream end of the mixing zone are of two types-those including samples from field surveys across the entire width of the mixing zone and those from Station 8, which includes samples only at the left-hand corner of the mixing zone (e.g., see Figure 2). Higher priority is given to matching data from field surveys, since such measurements are made across the entire width of the plume mixing zone and are more representative of the average temperature in the thermal plume at the 5-foot compliance depth. Previous Calibration Data and Calibration Work Prior to the NPDES permit of March 2011, field surveys were performed in 1981, 1982, 1983, 1987, 1996, 1997, 1999, 2000, 2002, 2003, 2004, 2006, and 2007. In July 1981, TVA conducted the first field survey of the SQN thermal discharge (TVA, 1982). The results of the field surveys were compared to projections from modeling relationships developed from mixing theory and a physical model test of the discharge diffusers. Adequate agreement was achieved between measured data and model projections. In cases where there were discrepancies, the model under-predicted the observed dilutions (i.e., over-predicted temperatures).

Between April 1982 and March 1983, five field surveys containing seventeen sets of samples across the downstream end of the mixing zone were performed to acquire data for validation of the computed compliance technique (TVA, 1983a). The results of these surveys are given in Table 2. Only one SQN unit was operating during the March 1983 test-the other five tests were for operation with two units. The results of the numerical model compared favorably with the field-measured downstream temperatures. On average, the discrepancy between the measured and computed downstream temperatures was about 0.40 F° (0.22 C°). Since the accuracy of the temperature sensors used by TVA are only about +/-0.25 F° (+/-0.14 C°), the agreement between the field measurements and the computer model was considered good. A similar comparison between the Station 8 and Station 11 temperatures and the measured average temperatures across the downstream edge of the mixing zone revealed that the discrepancy for Station 8 was about 0.79 F° (0.44 C°) and for Station 11 about 0.65 F° (0.36 C°). Consequently, it was concluded 14 that the numerical model is not only an accurate representation of the downstream temperature but also is likely superior to the monitoring approach using Station 8 and Station 11.

In September 1987, TVA released a report describing the field surveys in support of the validation and calibration of the SQN numerical model that had been performed up to that date (TVA, 1987). In the report, a chart was introduced that described the ambient and operational conditions for which field surveys had been performed. This chart indicated combinations of river flow, season, and number of operating units, showing what tests had been performed, and assigning relative priorities for tests to be performed in the future. With this guidance, six more field surveys were performed between March 1996 and April 2003, to measure downstream temperatures for various river flows and at different times of year. The results of these surveys produced ten sets of samples across the downstream end of the mixing zone, as given in Table 3.

Between 2004 and 2007 a number of additional field surveys were performed, providing twenty-three more sets of samples containing temperature measurements across the downstream end of the diffuser mixing for various river flows and at different times of the year. The results of these surveys are given in Table 4.

Table 2. Thermal Surveys at SQN from April 1982 through March 1983 Date Approx Time River Temperatures (5-foot depth) Flow (cfs) Stage (ft MSL)Tu Td T Measured (F) Measured (F) Measured (F) 04/04/1982 0900 CST 19900 676.46 56.8 61.9 5.1 04/04/1982 1000 CST 19800 676.46 56.7 60.1 3.4 04/04/1982 1100 CST 19600 676.47 56.7 61.2 4.5 04/04/1982 1200 CST 19700 676.50 57.2 61.9 4.7 04/04/1982 1300 CST 19700 676.45 57.4 62.2 4.8 05/14/1982 0900 CDT 7200 682.43 74.5 71.8 -2.7 05/14/1982 1100 CDT 9100 682.40 73.4 71.8 -1.6 05/14/1982 1300 CDT 6300 682.42 72.1 73.6 1.5 09/02/1982 1400 CDT 38500 680.30 78.1 80.1 2.0 11/10/1982 1300 CST 36200 677.57 59.0 60.1 1.1 11/10/1982 1400 CST 31600 677.59 59.0 60.6 1.6 11/10/1982 1500 CST 32300 677.58 59.0 60.4 1.4 03/31/1983 1100 CST 9800 676.34 51.4 54.3 2.9 03/31/1983 1200 CST 9400 676.34 50.4 54.7 4.3 03/31/1983 1300 CST 9300 676.34 52.5 54.5 2.0 03/31/1983 1400 CST 9500 676.34 51.4 54.9 3.5 03/31/1983 1500 CST 9400 676.36 51.4 54.9 3.5

15 Table 3. Thermal Surveys at SQN from March 1996 through April 2003 Date Approx Time River Temperatures (5-foot depth) Flow (cfs) Stage (ft MSL) Tu Td T Measured (F) Measured (F) Measured (F) 03/01/1996 1100 CST 42456 676.96 45.9 48.8 2.9 03/01/1996 1445 CST 28136 677.04 46.2 50.2 4.0 03/01/1996 1600 CST 21962 677.00 46.1 51.4 5.3 03/01/1996 1700 CST 20280 677.00 46.0 51.5 5.5 07/24/1997 1550 CDT 40441 682.57 83.5 84.7 1.2 03/24/1999* 1250 CST 35731 677.46 51.9 54.5 2.7 08/02/2000 1000 CDT 12472 682.20 82.1 85.1 3.0 08/02/2000 1100 CDT 8624 682.20 82.1 85.3 3.1 07/27/2002 1250 CDT 17231 682.37 84.0 86.6 2.6 04/23/2003 1445 CDT 34178 682.53 63.7 64.2 0.5

  • The survey of 03/24/1999 is lacking valid upstream temperature data and was not used in the calibration. Table 4. Thermal Surveys at SQN from February 2004 through November 2007 Date Approx Time River Temperatures (5-foot depth) Flow (cfs) Stage (ft MSL) Tu Td T Measured (F) Measured (F) Measured (F) 02/14/2004 0600 CST 51133 677.50 43.7 46.3 2.6 02/22/2004 1800 CST 18468 678.40 45.8 50.5 4.7 08/22/2004 1800 CST 12340 682.00 79.8 84.1 4.3 08/23/2004 1800 CST 39238 682.20 79.8 82.4 2.6 04/01/2006 1915 CST 7084 677.20 59.7 63.5 3.8 04/04/2006 0015 CST 7996 677.70 59.3 63.9 4.6 04/04/2006 1105 CST 8251 677.80 59.6 61.3 1.7 04/04/2006 2030 CST 8258 678.00 59.0 63.2 4.2 04/05/2006 0915 CST 7917 678.20 59.2 62.8 3.6 04/05/2006 2215 CST 8277 678.40 60.4 64.2 3.8 04/06/2006 0915 CST 8174 678.50 59.7 63.3 3.6 04/06/2006 2315 CST 8077 678.70 61.0 64.5 3.5 04/07/2006 0840 CST 8162 678.80 59.9 63.9 4.0 04/07/2006 1435 CST 7889 678.80 60.0 64.7 4.7 05/22/2006 1445 CST 14511 682.00 73.4 72.9 -0.5 05/23/2006 1455 CST 17878 682.20 73.5 73.9 0.4 05/28/2006 1440 CST 13396 682.30 76.6 76.7 0.1 05/29/2006 1435 CST 13713 682.40 77.5 77.6 0.1 05/30/2006 1425 CST 14304 682.40 79.7 79.2 -0.5 09/20/2007 1200 CST 8545 681.80 79.3 83.4 4.1 09/21/2007 1300 CST 8629 681.70 80.6 82.5 1.9 09/22/2007 0600 CST 6969 681.70 79.5 81.8 2.3 11/04/2007 1200 CST 7664 678.70 64.9 69.5 4.6 16 The most recent calibration of the numerical model was performed in 2009 to support the NPDES permit of September 2005 (TVA, 2009). The data from Table 2, Table 3, and Table 4 were used in this calibration. The average overall discrepancy between the measured and computed downstream temperatures was about 0.55 Fº (0.31 Cº). For downstream temperatures above 75ºF, the average discrepancy improved to about 0.38 Fº (0.21 Cº). New Calibration Data and Calibration Work Since the 2009 model calibration, an additional field study was performed in November 2012 (Table 5). The study included the operation of one unit at SQN and was conducted concurrently with independent measurements for the discharge through the diffusers (TVA, 2013). With this, altogether fifty data points with sets of temperature samples across the downstream end of the mixing zone were available for updating the model calibration (i.e., Table 2 through Table 5). Table 5. Thermal Surveys at SQN from November 2012 Date Approx Time River Temperatures (5-foot depth) Flow (cfs) Stage (ft MSL) Tu Td T Measured (F) Measured (F) Measured (F) 11/16/2012 1400 CST 12599 678.62 57.0 60.3 3.3 Diffuser Slot Width The effective slot width for a multiport diffuser of the type at SQN can be assumed to fall somewhere between the width of a rectangle with length equal to that of the diffuser section and area equal to the total area of the ports; and the width a rectangle with length equal to that of the diffuser section and area equal to the arc length of the perforated section of the diffuser. For the SQN diffuser, this slot width would be between 0.37 feet and 2.67 feet. Multiple slot widths in this range were evaluated and compared with fifty measured data points from the field surveys (i.e., from Table 2 through Table 5). The results, given in Figure 6, show that larger slot widths yielded better agreement with the measured data. The nominal arc length of the perforated section of the diffuser (i.e., 2.67 feet) was selected as the best diffuser slot width to be used in the numerical model. This is the same value used in the 2009 model calibration. Plume Entrainment Coefficient Figure 7 shows the comparison with measured data of downstream temperatures computed with the McIntosh (Eq. 22) and Benton (Eq. 24) entrainment coefficients, again based on fifty data points from the field surveys in Table 2 through Table 5. Both entrainment coefficients result in relatively close matches with the measured data. Although the McIntosh coefficient seems to perform better at low ambient river temperatures, temperatures computed using the Benton coefficient more closely match measured downstream temperatures at higher river temperatures.

17 Since the accuracy of the computation is more critical at temperatures approaching the NPDES limit for downstream temperature, the Benton coefficient, Eq. (24) is used in the compliance model.

Figure 6. Sensitivity of Computed Temperature Td to Diffuser Effective Slot Width 45505560 657075 80859045505560657075808590Computed (oF)Measured (oF)Field Data -1982 -2012 Line of perfect agreementB0 = 0.37 ftB0 =1.137 ftB0 = 1.903 ftB0 = 2.67 ftB0 = 3.437 ft 18 Figure 7. Sensitivity of Computed Temperature Td to Plume Entrainment Coefficient Diffuser Effluent Re-Entrainment Based on the evaluation of numerous combinations of N and R for diffuser effluent re-entrainment (Eq. 20 and 21), Table 6 gives the values that resulted in computed downstream temperatures that most closely matched measurements in the field surveys (i.e., fifty data points from Table 2 through Table 5). For river velocities between the values given in Table 6, the re-entrainment factor R is interpolated between the table values. The number of iterations N is interpolated and then rounded to the nearest integer. No re-entrainment correction is performed for 24-hour river velocities greater than the highest value in the table.

Figure 8 shows the comparison of measured and computed downstream temperatures with and without the correction for plume re-entrainment as given in Table 6. Temperatures computed using the plume re-entrainment correction more closely matched measured values for twenty-seven of the fifty data points. Temperatures computed without using the plume re-entrainment correction more closely matched measured values for six data points, with no significant differences for the remaining data points. Based upon these results the re-entrainment correction method is used. 4550 55 60 657075 80 85 9045505560657075808590Computed (oF)Measured (oF)Field Data -1982-2012Line of perfect agreementBenton Entrainment Coefficient McIntosh Entrainment Coefficient 19 Table 6. Plume Re-Entrainment Iteration Numbers and Factors River Velocity (ft/sec) Number of IterationsN Re-entrainment Factor R 0.000 3 0.21930 0.050 3 0.13300 0.075 3 0.11000 0.100 3 0.10000 0.200 3 0.02670 0.300 3 0.03507 0.400 3 0.00893 0.500 3 0.00447 0.600 0 0.00000 Figure 8. Sensitivity of Computed Temperature Td to Effluent Re-Entrainment Function 4550556065707580859045505560657075808590Computed (oF)Measured (oF)Field Data -1982-2012Line of perfect agreementUsing Plume ReentrainmentNot Using Plume Reentrainment 20 Results of Updated Calibration For the assumed diffuser slot width and entrainment coefficient, and updated calibration including the re-entrainment function for low river flow, the computed and measured downstream temperatures for the fifty downstream temperature data points collected in SQN field surveys since March 1982 are shown in Figure 9. The average discrepancy between the measured and computed downstream temperatures was about 0.55 Fº (0.31 Cº). For downstream temperatures above 75ºF, the average discrepancy was 0.38 Fº (0.21 Cº). There was no significant change in the model performance compared to the previous calibration.

To be consistent with the 24-hour averaging specified in the current NPDES permit, the 24-hour average temperatures measured in 2010 at the downstream temperature monitor, Station 8, are compared to those computed by numerical model in Figure 10. 2010 was selected because it represents a new climatic extreme in East Tennessee for the period of record for this model. As before, the measured temperatures correspond to the average of sensor readings at the 3-foot, 5-foot, and 7-foot depths. The overall average discrepancy between the measured and computed 24-hour average downstream temperatures was about 0.71 Fº (0.39 Cº), and about 0.63 Fº (0.35 Cº) for downstream temperatures above 75ºF.

Measured downstream hourly average temperatures for the same time period are compared to those computed by numerical model in Figure 11. As expected, the temperature data are much more scattered for the hourly temperatures. The average discrepancy between the measured and computed hourly average downstream temperatures was 0.86 Fº (0.48 Cº) for the full range of river temperatures, decreasing to 0.71 Fº (0.39 Cº) for downstream temperatures above 75ºF.

It needs to be emphasized that in Figure 10 and Figure 11, the data from Station 8 is not necessarily representative of the average temperature across the downstream end of the mixing zone. However, in monitoring the NPDES compliance for Outfall 101, data from Station 8 is considered valuable for verifying basic trends in the downstream temperature as determined by the numerical model, thus providing the motivation for presenting the comparisons given in these figures.

21 Figure 9. Comparison of Computed and Measured Temperatures Td for Field Studies from April 1982 through November 2012 Figure 10. Comparison of Computed and Measured 24-hour Average Temperatures Td for Station 8 for 2010 4550556065 707580859045505560657075808590Computed (oF)Measured (oF)Line of perfect agreementField Data 1982 -20124045 50 55 60 65 70 75 80 85 904045505560657075808590Computed (oF)Measured(oF)Line of perfect agreementMeasured 2010Erroneous data due to faulty sensor--values removed from discrepancy calculations 22 Figure 11. Comparison of Computed and Measured Hourly Average Temperatures Td for Station 8 for 2010404550 55 60 65 70 75 80 85 904045505560657075808590Computed (oF)Measured (oF)Line of perfect agreementMeasured 2010Erroneous data due to faulty sensor--values removed from discrepancy calculations 23 CONCLUSIONS The numerical model for the SQN effluent discharge computes the temperature at the downstream end of the mixing zone with sufficient accuracy for use as the primary method of verifying thermal compliance for Outfall 101. In the updated calibration study summarized herein, which used the results from fifty sets of temperature samples across the downstream end of the diffuser mixing zone, the average discrepancy between the measured and computed downstream temperatures was about 0.55 Fº (0.31 Cº). For downstream temperatures above 75ºF, the average discrepancy improved to about 0.38 Fº (0.21 Cº). There was no significant change in the model performance compared to the previous calibration, and as a result, no update was required in the model parameter set.

24 REFERENCES Benton, D.J. (2003), "Development of a Two-Dimensional Plume Model," Dynamic Solutions, LLC, Knoxville, Tennessee, May 2003.

Fischer, H. B., E. J. List, R. C. Y. Yoh, J. Imberger, and N. H. Brooks (1979), Mixing in Inland and Coastal Waters, Academic Press: New York, 1979. TDEC (2005), "NPDES Permit No. TN0026450, Authorization to discharge under the National Pollutant Discharge Elimination System (NPDES)", Tennessee Department of Environment and Conservation, Division of Water Pollution Control, Nashville, Tennessee 37243-1534, July 29, 2005.

TDEC (2011), "NPDES Permit No. TN0026450, Authorization to discharge under the National Pollutant Discharge Elimination System (NPDES)", Tennessee Department of Environment and Conservation, Division of Water Pollution Control, Nashville, Tennessee 37243-1534, January 31, 2011.

TVA (1982), McIntosh, D.A., B.E. Johnson, and E.B. Speaks, "A Field Verification of Sequoyah Nuclear Plant Diffuser Performance Model One-Unit Operation," TVA Division of Air and Water Resources, Water Systems Development Branch, Report No. WR28-1-45-110, October 1982.

TVA (1983a), McIntosh, D.A., B.E. Johnson, and E.B. Speaks, "Validation of Computerized Thermal Compliance and Plume Development at Sequoyah Nuclear Plant," Tennessee Valley Authority, Division of Air and Water Resources, Water Systems Development Branch Report No. WR28-l-45-115, August 1983.

TVA (1983b), Waldrop, W.R., and D.A. McIntosh, Real-Time Computation of Compliance with Thermal Water Quality Standards, Proceedings of Microcomputers in Civil Engineering, University of Central Florida, Orlando, Florida, November 1983.

TVA (1987), Ostrowski, P., and M.C. Shiao, "Quality Program for Verification of Sequoyah Nuclear Plant Thermal Computed Compliance System," Tennessee Valley Authority, Office of Natural Resources and Economic Development, Division of Air and Water Resources Report No. WR28-3-45-134, September 1987.

TVA (2003), Harper, W.L., "Study to Confirm the Calibration of the Numerical Model for the Thermal Discharge from Sequoyah Nuclear Plant as Required by NPDES Permit No. TN0026450 of August 2001, Report No. WR2003-1-45-149, Tennessee Valley Authority, River Operations, June 2003.

25 TVA (2009), Harper, W.L. and P.N. Hopping, "Study to Confirm the Calibration of the Numerical Model for the Thermal Discharge from Sequoyah Nuclear Plant as Required by NPDES Permit No. TN0026450 of September 2005, Report No. WR2009-1-45-150, Tennessee Valley Authority, River Operations, January 2009. TVA (2009), "Ambient Temperature and Mixing Zone Studies for Sequoyah Nuclear Plant as Required by NPDES Permit No. TN0026450 of September 2005," Report No.

WR2009-1-45-151, Tennessee Valley Authority, River Operations, January 2009.

TVA (2010), "Sequoyah Nuclear Plant (SQN) - Revised Thermal Performance Baseline and Capacity Ratings," Memo from Scott D. Terry to J.D. Williams (B85100419001),

April 14, 2010.

TVA (2013), "Sequoyah Nuclear Plant (SQN)--Update of Flowrate Characteristics Through the Diffusers," Memo from Paul N. Hopping to Bradley M. Love, March 4, 2013.

... RECEIVED STATE OF TENNESSEE 90 JAN 18 Ai'lIO: 05 DEPARTMENT OF HEALTH AND ENVIRONMENT r-r,'*-u. SECil(r,,{R):::OF'ST,"TE IN THE l-1ATTER OF: TENNESSEE VALLEY AUTHORITY RESPONDENT ) ) ) ) ) ) ) ) ) OFFICE OF WATER MANAGEMENT DIVISION OF WATER POLLUTION CONTROL No. 89-3036 DdCKET No. 17.30-D-89-0674A AGREED ORDER This cause came to be heard before the Water Quality Control Board in open meeting upon the motion of the parties that the* Board approve the parties' settlement as embodied herein. By signatures of the parties' counsel, as entered below, representing that each attorney is acting with tne full and explicit authority of their clients, the Board finds that these named parties have agreed to the terms and conditions of this agreed and final order as a resolution between said 'parties regarding the Commissioners's Order and Assessment issued to Respondent on May 22, 1989. The *Commiss'ioner's Order and Assessment' alleg;es that fish were killed as a result of the operation 'of Respondent TVA's Sequoyah Nuclear Plant in the summer of 1988 in violation of T.C.A. Section 69-3-114(a) and (b) Division personnel determined the cause of the fish kills to be low, dissol ved oxygen and high temperature conditions in the waters affected by Respondent's operation of Sequoyah Nuclear Plant. TVA contends that during this period, thermal requirements in the plant's Naticrli:1l :E-ollutant Discharge Elimination System (NPDES) permit No. TN0026450 were not violated and that diss,olved oxygen levels were not lowered due to operation of the plant in accordance

.. with the NPDES permit. However, TVA desires resolve this matter as provided herein. The Board now finds the Agreement of these parties *to be as follows, and it is so found and ordered by the Board that: FINDINGS OF FACT I I. TVA is a co:cpor.ate agency and instrumentality of the United States . Government. It operates the Sequoyah Nuclear Plant* for the purpose of producing electrical power as authorized by an act of Congress known as the Tennessee Valley Authority Act of 1933, 16 U.S.C. SS 831-831dd (1988). 2. TVA is authorized to discharge wastewater from a facility' located at the Sequoyah Nuclear Plant in Hamilton County, Tennessee, to receiving waters named Tenness.ee River, Plant Intake Embayment (hereinafter "Intake Embayment"), and Diffuser Pond in accordance with the terms and conditions of NPDES permit No.TN0026450. The NPDES permit was issued by the United States Environmental Protection Agency in conjunction with the State of Tennessee's Certification Conditions. Tennessee's Certification Conditions state that TVA is in no way relieved from any liability for damages which might .result from the discharge of wastewater. The primary nature of the wastewater in question is a ther:llal discharge resulting from TVA's plant operations. 3. Cooling water for TVA's Sequoyah Nuclear Plant is drawn into the Intake Embayment below a deep skimmer wall to provide cooler water from the lower depths of the Tennessee River. The bottom of the skimmer wall is about 12 feet from the river bottom and 'i'lbout 39.5 fest* below the normal maximum summer elevation of the water. surface. Dissolved oxygen and temperature conditions in the Intake Embayment are thus related to the conditions present in the lower strata of the river .where summer temperatures are cooler and summer dissolved oxygen levels are lower than those in the lower strata.

... 4. In open mode operation, the cooling water is discharged from* the condensers into the Diffuser Pond and then to the Tennessee River through two diffusers. In mode, the cooling water is pumped through the cooling towers into the Diffuser Pond and then discharged to the Tennessee River through the diffusers. In closed mode, the cooling wat.er. is pumped through the. cooling towers and into the Intake Embayment. The plant was operated in open mode until approximately 6:30 p.m. on August 2 when operation in helper mode commenced to lower the temperature of the discharged water. 5. The Tennessee River, Intake Embayment, and Diffuser Pond are "waters" of* the State, as defined by T.C.A. Section 69-3-103(33). Pursuant to Section 69-3-105(a)(1), all waters of the State of Tennessee have been classified by the Tennessee Water Quality Control Board for suitable uses. The above waters* are classified by .Rule 1200-4-4-.01 of *the Official Compilation, Rules and Regulations of the State of Tennessee ( hereinafter referred to as Rules) all classified uses including the use of fish and aquatic life. The waters of the Diffuser Pond are physically separated from the Tennessee River by a dike. 6. In addition to earlier reported fish kill events, the Division was notified by TVA on August I., 1988, of a fish kill in the Intake Embayment at sequoyC!h Nuclear Plant. Division personnel investigated the reported fish kill and counted 278 dead fish in the Intake Embayment. A reading of the dissolved oxygen at the location of the fish kill ranged from*O. 2* to 0.7 mg!l. 7. On August 2, 1988, a second was conducted. The dissolved oxygen present in the Intake Embayment was measured by Division personnel. On.e location showed dissdlved oxygen to range from 1.9 to 2.5 mg/l. A second location showed dissolved oxygen to range from 0.2 to 0.4 mg/l.

., The Diffuser Pond was also inspected on this date. Dead and dying fish were observed. The temperature of the water in the Diffuser Pond was measured at 37°C (98°F) (within allowable temperature limits under NPDES permit No. TN00264S0 for the Diffuser Pond). Dissolved oxygen was less than 1.0 mg/l: B.. On August 4, 1988, Division personnel took measurements of .dissolved oxygen in the Tennessee River. Midchannel dissolved *oxygen readings at theS-footdepth ranged from 4.3 to 8.7 rog/l with most readings approximating 7.5 mg/l. Dissolved oxygen readings at the IS-foot depth and below, from where water is drawn into the Intake Embayment below the deep skimmer wall, corresponded to the. dissolyed oxygen* levels. in the Intake Embayment. 9. On August 25, 198B, the Division received a report from TVA regarding the August 1, 1988, fish kill. The report, stated that the loss of fish in the Intake Embayment was undoubtedly related to extremely low dissolved oxygen levels** in the Intake Embayment. 10. In October of 1988, TVA submitted a report to the Division on "The Effects of Sequoyah Nuclear Plant on 'Temperature and Dissolved Oxygen in Chickamauga Reservoir During Summer 1988" in response to the Division's request that TVA document the conditions in the reservoir and actions taken by TVA to mitigate the impacts of its therJT.al discharge. TVA reported that it had released cold water from Norris Dam in an effort to .lower water temperatures and raise the level of dissolved oxygen in the water. Also! cooJ.er*water from Watts Bar Dam and near b5.nk turbines were used to achieve higher dissolved oxygen releases from Watts Bar Darn. It was also reported that water entered* Seguoyah at approximately 27.5°C (B2°P), was warmed to about 40.5°C (105°F) through the plant, cooled to about 3PC (88°F) with a cooling tower (after switching to helper mode on August 2), then discharged back to the reservoir through the Diffuser Pond at approximately 31.7°C (89.8°F) in complianc;e with applicable

"-thermal criteria established in the NPDES permi"t for the Diffuser Pond discharge. The repo"rted temperatures were based upon an "August 25, 1988, in-plant survey. 11. On October 20, 1988, the Division" received a summary from TVA of dead fish observed" in the Sequoyah Nuclear Plant Intake Embayment and Diffuser Pond from August 3 to September 14, 1988. The total number of dead fish observed during this time period was reported to be 16,372 in the Intake Embayment and 392 in the Diffuser Pond. 12. On March 14, 1989, the Division received a report from the Tennessee Wildlife Resources Agency ("TWRA") which contained calculations of fishery value loss "and TWRA personnel salary expenses. TWRA reported the following costs: Diffuser Pond Total value lost: Personnel salaries: Total Intake Embayment Total fishery value lost: Personnel salaries: Total $ 56.92 95.03 $151. 95 $1,233.93 117.39 $1,351.3"2 13. The Division has incurred costs in the form of expenses for "travel, salaries, and analyses costs in the amount of $588.70. 14. TVA has cooperated with the Division in its investigations.

.. CONCLUSIONS OF LAW 1. The operation of the intake pumps at TVA's Sequoyah Nuclear Plant to draw low dissolved oxygen water into the Intake Embayment and the discharge of heated water into the Diffuser Pond caused a condition which resulted in harm to fish in said embayment and pond for which condition, if not properiy authorized, the Commissioner may assess damages under T. C.A. Section 69-3-116. 2. A discharge resulting in harm to fish and aquatic li'fe which is not properly authorized is pollution and in violation of T.e.A. Section 69-3-114(a) and (b). ORDER WHEREFORE, premises considered, it is Ordered by the Board that TVA shall: 1. Operate Sequoyah Nuclear Plant in full compliance with it.s NPDES permit and applicable provisions of the Act and rules promulgated thereunder. 2. Pay the State of Tennessee a monetary amount of TWO THOUSAND NINETY-ONE DOLLARS AND NINETY,..SEVEN CENTS ($2,091.97) within thirty (30) days of the effective date of this Order. 3. Prepare and submit a plan to the Division, within ninety (9 0) days of receipt of this Order, which details TVA's proposed systems and procedures to prevent damage to fish and aquatic life from TVA's.discharges. Either party may request that the Board review and receive comments on the plan from the parties.

4. The facts and conclusions of law recited herein are to be used only in administrative proceedings before the Board between these parties. Neither party waives any rights or defenses regarding the facts and conclusions of law stated herein by entering into this Agreed Order. Furthermorer TVA is advised that the foregoing Order is not in any way to be construed as a waiverr express or impliedr of any provision of the law or regulations r i'ncludinq, but not limited tOr future enforcement for violations of the Act .and Regulations* which are not charged as violations of this Order. However, compliance with the Order will be one factor considered in any decision whether to take enforcement action against TVA in the future. REASONS FOR DECISION It appears to* the Board that the parties signatory hereto have proposed this Order in good faith and in the interest of settling these proceedings in accord and in the interest of avoiding the time and expense of prolonged litigation. The Board has reviewed the Order and finds nothing in it which is contrary to the public interest and the purposes and intent of the Water Quality Control Act. The Board wishes to encourage such agreed resolutions when they do not endanger public healthr safetYr and welfare, consistent with the provisions of the Uniform Adnd.nist.r.o,tive Procedures Act which encourage informal settlements as a means to resolve a contested case. The proposed final order is proper and. lawful. There being no good and satis'factory reason for the Board to set aside the voluntary agreement of the parties ri t will be approved as they have executed it.

.. REVIEW OF THE FINAL ORDER Any person aggrieved by the entry of this Order is entitled to file a petition for reconsideration before the Board within ten (10) days after the date of entry of .this Order. If no action is taken upon the petition within twenty (20) days of its receipt by the Board, the petition shall be deemed to have been denied. See T.C.A. Section 4-5-317. Further, any party may petition the Board to stay the effectiveness of this Order within seven (7) days of its entry. See T.C.A. Section 4-5-316. Any person aggrieved by the entry of this Order is entitled to petition the Chancery Court of Davidson County for review within sixty (60) days 0+ the entry of this Order. See T.C.A. Section 69-3-111 and 'Section 4-5-322. A, petition for reconsideration of the Order does not act to extend this sixty (60) day period which begins to run on the effective date of the Order disposing of the petition. This the 17 day of Chairman The Tennessee Water Quality Control Board APPROVED FOR ENTRY: FOR THE COMMISSIONER OF THE TENNESSEE DEPARTMENT OF HEALTH AND ENVIRONMENT ... b.fox' -James E. Fox, Deputy General Counsel Attorney for Respondent, Tennessee Valley Filed in the Administrative Procedures Division, Office of the Secretary of State, on this 1990. E3149 320 I D6/0GC Charles C. Sullivan, II, Director Administrative Procedures Division

" / ,J>urpose: }'rocedure: PROCEDURE ,S eglibyiliNtidlear1?lant ," . 'Operating Procedure for Intake:Forebay:FishRefuge This :procedure .identifies, (1) how low dissolved oxygen (DO) concentrations within:the Sequo.yah NuClear :Plant (SQN) Intake -p orebay willbe-predicted;'(2) howSQN -will create 'aDO enhanced :fish refuge within the lntake :F orebayio :prevent. a -possible DO induced :fish 'kill; and *(3) establishes protocol interfaces with appropriate State agencies. N orris Engineering Laboratory will monitor Chickamauga Reservoir :for DO concentrations. Methodology employed will include continuous:measurement of DO irom:stations in the 'Watts Bar Bydro(WBH) tailrace. Additional DO measurements will be taken routinely :from .stations located at Tennessee River Miles (TRM)-472:3 and 490.:5. The SQN intake is located between these stations at TRM 484.7. 'NorrisEngineeringLaboratorywill use the:BoxExchange Transport Temperature Ecology Reservoir (BETTER) model to simulate "Chickamauga Reservoir and predict DO concentrations ahheSQN intake skimmer wall. Results will be displayed on the TVAEnvironment and River Resource Aide (TERRA) soihatpredictions are availableio Reservoir System Operations, Environmental Compliance, :and SQNEnvironmentalSection. DOpredictions the model will be updated daily (Monday through :Friday). 'The:predictions will cover:a :period of-three days .and will use ,the 'most recent data -for -measured no, forecast meteoro logy, .and forecast :riverflows. 'Engineering '.Services Central Region :and SQN Environmental Section will 'be alerted by Norris Engineering Laboratory if the measured or'thepredicted DO at the SQN intake skimmer dropsto-4.0mg/L or lower. Norris Engineering 'Laboratory will alert ,SQN Environmental Section to implement ., ...... uIJuuF. if: '. The measured or predicted DO at any station drops to 'below '2.:5mgIL (i,e.,-WBHtailrace, TRM-472.3, or TRM 490.:5). .* Thepredicted.DO attheSQN skimmer drops to 3.0 mgIL. ,:' ,.'; ; i* i I* I I I f

/ .To implement dailysampling,SQN Environmental Section will ensure that DOmeasurementsaretaken.at depths 0.3, I,J"and5meters onthe"inside of the .skimmer wall, .and on*the outside of the skimmer wall at approximately 14 meters 'below the top of-the wall* (center* of the submerged opening).S QN Environmental :Section will ensure'that:there.are visual inspections of the intakeforebayfor :stressed fish at the'water .surface .. Alternately, :sampling and visual :may :be performed by Engineering .services ,-Centnil Region as the situation dictates . The organization collecting .samples and.visuals will report results io 'Water 'Management Environmental Compliance in 'Chattanooga and to the 'Norris Engineering Laboratory. The SQNEnvironmental ancrWasteControl manager or designeewi11.advise SQNOperations during each moming's shift turnover meeting oftheDO levels and predicted trends in:the SQN.intakeforebay when dailyDO sampling is initiated. Aeration system openibilitywillbe ensured' daily. Aeration effectiveness 'at several forebay'locations will be detennined byweeldysampJing at 0:3, 1,:3 ,and 5..;meter ' ,Aeration systemilow'vvilrbe initiated whenever any of the following conditions are met* .. '. If the measured DO at the center of the intake skinuner wall opening (14-meter depth) onthe outside of the skimnierwalLfalls between2.0 and 2.:5 mgIL Jor .2 .consecutive daily samples. , Ifthe.measured'DO of anyone daily sample fallsbetween 2. 0 and , .and TERRAreflects:aprediction of constant or worsening conditions. 'Whenevedhe measured DO of any daily sample drops -to 2. 0 :mgIL or .lower. 'WhenevertheineasuredDO at the center of the skimmer wall opening on the outside of the wall increases to above 2:5 mgIL for .2 consecutive daily samples and conditions are predicted to -remain stable or improve, aeration sampling will I I ! i I* l-,

Attachment

1 -Organizational Contacts Water ManagemenrEnvironrnental-Compliance WaneyBuilding --'Chattanooga) Woomer . -W l!-yne Wilson DonDycus .Jack Milligan 7.5J..:.7307 751-8961 75),-7322 751-7360 Engineering Services-CentniJRegion (power Service Center--Chickamauga Dam) .RobertBond ]erryLiner Garry' Grant -Secretary . 697-4108 697-4100 697-4380 697-4263 Engineering 'Services -Norris Engineering -Laboratory Ming'Shiao -Walter Harper Switchboard 632-1886 632-1882 632-1900 Corporate Environmental Protection (Nuclear) Diedre ::Nida Debby.Bodine lamar Strickland . Stephanie Howard Jerry Osborne :Shlft*Operations 'Supervisor Jim Baumstark 7.51-8123 'Sequoyah Environmental Section 843-6700, Pager Number 10496 843-7748, -Pager Number 10861 843-6713, Pager Number 60438 843-7630, Pager Number 90091 843-6211 843-6501

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