Text

National Pollutant Discharge Elimination System Permit No. TN0026450 Approved Changes
	ML110660596
Person / Time
Site:	Sequoyah
Issue date:	03/02/2011
From:	Krich R; Tennessee Valley Authority
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	TN0026450
	Download: ML110660596 (85)
	v • d • e

Tennessee Valley Authority 1101 Market Street, LP 3R Chattanooga, Tennessee 37402-2801 R. M. Krich Vice President Nuclear Licensing March 2, 2011 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Units 1 and 2 Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328

Subject:

National Pollutant Discharge Elimination System Permit No. TN0026450 Approved Changes The enclosure provides the approved changes to Sequoyah Nuclear Plant (SQN)

National Pollutant Discharge Elimination System (NPDES) Permit No. TN0026450 as required by SQN Environmental Technical Specification Section 5.5.2, Changes in Permits and Certifications.

There are no regulatory commitments associated with this submittal. If you have any questions concerning this matter, please contact James W. Proffitt at (423) 843-6651.

Respectfully, R. M. Krich

Enclosure:

NPDES Permit No. TN0026450 cc (Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant coo(

printed on recycled paper

U.S. Nuclear Regulatory Commission Page 2 March 3, 2011 JWP:SKD Enclosure bcc (Enclosure):

NRC Project Manager - Sequoyah Nuclear Plant P. M. Billingsley T. J. Bradshaw G. M. Cook R. M. Cook R. E. Detwiler S. K. Dunn K. Langdon M. D. Skaggs P. D. Swafford E. J. Vigluicci EDMS, WT CA-K P:\Licensing and Industry Affairs\CorpLicensing\NuclearLicensing\corp_lic\NRC\Sequoyah\NPDES Permit\NPDES Permit No. TN0026450 approval.docx

ENCLOSURE TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM PERMIT NO. TN0026450 The following provides an overview of the changes to National Pollutant Discharge Elimination System Permit for the Sequoyah Nuclear Plant.

Outfall 101 (Diffuser Pond discharge)

Monitoring requirements for annual polychlorinated biphenyl (i.e., PCB), weekly pH, monthly oil and grease (O&G), monthly total suspended solids (TSS), and quarterly boron have been deleted.

Ouffall 103 (Low Volume Waste Treatment Pond discharge)

Mass calculations (i.e., pounds/day) requirements have been deleted.

Monitoring requirements for TSS and O&G have been reduced from weekly samples to twice per month samples.

Outfall 107 (Metal Cleaning Waste Ponds)

Monitoring requirements deleted for flow, pH, O&G, TSS, copper, iron, and phosphorus.

An allowance is provided to discharge rainfall into the Low Volume Waste Treatment Pond without any sampling.

The permit prohibits metal cleaning wastewater to be discharged to the metal cleaning ponds.

Outfalls 116 and 117 (Backwash to Condenser Circulating Water and Essential Raw Cooling Water).

Visual monitoring and reporting requirements have been deleted.

Outfall 118 (Settling Pond for dredged materials from Intake forebay)

Monitoring requirements only apply when the Settling Pond is in use as a settling basin for dredged sediments.

Diesel Fuel Oil Interceptor System

Monitoring of the Diesel Fuel Oil Interceptor System is no longer required.

STATE OF TENNESSEE DEPARTMENT OF ENVIRONMENT AND CONSERVATION DIVISION OF WATER POLLUTION CONTROL 401 CHURCH STREET L & C ANNEX 6TH FLOOR NASHVILLE TN 37243 Mr. Timothy P. Cleary FEB 0 2 2011 Site Vice President TVA Sequoyah Nuclear Plant Sequoyah Access Rd.

P.O. Box 2000 (OPS-4A)

Soddy Daisy, TN 37384

Subject:

NPDES Permit No. TN0026450 TVA - Sequoyah Nuclear Plant Soddy Daisy, Hamilton County, Tennessee

Dear Mr. Cleary:

In accordance with the provisions of the Tennessee Water Quality Control Act, Tennessee Code Annotated (T.C.A.), Sections 69-3-101 through 69-3-120, the Division of Water Pollution Control hereby issues the enclosed NPDES Permit. The continuance and/or reissuance of this NPDES Permit is contingent upon your meeting the conditions and requirements as stated therein.

Please be advised that a petition for permit appeal may be filed, pursuant to T.C.A. Section 69-3-105, subsection (i), by the permit applicant or by any aggrieved person who participated in the public comment period or gave testimony at a formal public hearing whose appeal is based upon any of the issues that were provided to the commissioner in writing during the public comment period or in testimony at a formal public hearing on the permit application. Additionally, for those permits for which the department gives public notice of a draft permit, any permit applicant or aggrieved person may base a permit appeal on any material change to conditions in the final permit from those in the draft, unless the material change has been subject to additional opportunity for public comment.

Any petition for permit appeal under this subsection (i) shall be filed with the board within thirty (30) days after public notice of the commissioner's decision to issue or deny the permit.

If you have questions, please contact the Division of Water Pollution Control at your local Field Office at 1-888-891-TDEC; or, at this office, please contact Mr. Bob Alexander at (615) 532-0659 or by E-mail at Robert.Alexander@ tn.gov.

Sincerely, Vojin Janjid

_.lianager, Permit Section Division of Water Pollution Control cc/ec: DWPC, Permit Section &Chattanooga Environmental Field Office Ms. Stephanie Howard, Environmental Engineer, TVA - Sequoyah Nuclear Plant, sahoward@tva.gov Ms. Linden (Lindy) P. Johnson, Manager -Water Permitting &Compliance, Ipjohnson@tva.gov Ms. Connie A. Kagey, NPDES Permit Section, EPA Region IV. Kagey.Connie@epamail.epa.gov Mr. Michael D. Skaggs, WBN Vice President, TVA - Watts Bar Nuclear Plant, mdskaggs@tva.gov Mr. Brian Paddock. Attorney, Save Our Cumberland Mountains (SOCM). bpaddock@twlakes.net

No. TN0026450 Authorization to discharge under the National Pollutant Discharge Elimination System (NPDES)

Issued By Tennessee Department of Environment and Conservation Division of Water Pollution Control 401 Church Street 6th Floor, L &C Annex Nashville, Tennessee 37243-1534 Under authority of the Tennessee Water Quality Control Act of 1977 (T.C.A. 69-3-101 et 5q.) and the delegation of authority from the United States Environmental Protection Agency under the Federal Water Pollution Control Act, as amended by the Clean Water Act of 1977 (33 U.S.C. 1251, -et§M.)

Discharger: TVA - SEQUOYAH NUCLEAR PLANT is authorized to discharge: process and non-process wastewater through Outfalls 101, 110, 116,117, and 118, and Internal Monitoring Points (IMP) 103, and 107 from a facility located: In Soddy Daisy, Hamilton County, Tennessee to receiving waters named: Tennessee River at mile 483.65 (Outfall 101), 485.2 (Outfall 116),

484.852 (Outfall 117), and 484.8 (Outfall 118) in accordance with effluent limitations, monitoring requirements and other conditions set forth herein.

This permit shall become effective on: March 1, 2011 This permit shall expire on: October 31, 2013 Issuance date: January 31, 2011 P ulo. Davis, Director D Wion of Water Pollution Control

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CN-0759 RDAs 2352 and 2366 2

PART I ....................................................................................................................................................................... 1 A. EFFLUENTLIM ITATIONS AND M ONITORING REQUIREMENTS .................................................................. I

1. OutfIoll 101 ................................................................................................................................................. 1

2. InternalM onitoringPoint (formerly Outfoll) 103 ................................................................................. 5

3. InternalM onitoringPoint (formerly Outfall) 107 ................................................................................. 5

4. Outfall110 ................................................................................................................................................. 5 "

5. Outfal ll16 and 117 ................................................................................................................................... 6

6. Outfal 1118 ................................................................................................................................................. 6

7. Additional monitoring requirementsand conditions applicable to all Outfalls include:............................. 6 D. REPORTING .......................................................................................................................................... :... 10

4. Outlier Data ............................................................................................................................................. 11 A. GENERAL PROVISIONS ..................................................................................................................................... 12

1. Duty to Reapply ............................................................................................................................................ 12

2. Right of Entry ................................................................................................................................................ 12

3. Availaobility of Reports................................................................................................................................... 12

4. ProperOperationand Maintenance ............................................................................................................. 13

5. Treatment Facility Failure ............................................................................................................................. 13

6. PropertyRights ............................................................................................................................................. 13

7. Severability ................................................................................................................................................... 13

8. Otherinform aotion ........................................................................................................................................ 13 B. CHANGESAFFECTING THE PERM IT.................................................................................................................. 14

1. Planned Changes .......................................................................................................................................... 14

2. PermitModification, Revocation, or Termination................................................................................... 14

3. Cha onge of Ownership................................................................................................................................... 15

4. Change of Mailing Address........................................................................................................................... 15 C. NONCOM PLIANCE ........................................................................................................................................... 15

1. Effect of Noncompliance ............................................................................................................................... 15

2. Reporting of Noncompliance........................................................................................................................ 16

3. Overflow ....................................................................................................................................................... 16

4. Upset ............................................................................................................................................................ 17

5. Adverse Impact............................................................................................................................................. 18

6. Bypass ........................................................................................................................................................... 18 D. LIABILITIES ....................................................................................................................................................... 19

1. Civil ond Criminol Liobility ............................................................................................................................ 19

2. Liability Under State Low .............................................................................................................................. 19 OTHER REQUIREM ENTS ......................................................................................................................................... 20 B. REOPENER CLAUSE .......................................................................................................................................... 20 C. PLACEM ENTOFSIGNS ..................................................................................................................................... 21 D. ANTIDEGRADATION ........................................................................................................................................ 21 STORM WATER POLLUTION PREVENTION PLAN ............................................................................................... 27 B. BIOCIDE/CORROSION TREATM ENT PLAN (B/CTP) ..................................................................................... 27 ADDENDUM TO RATIONALE ........................................................ ............................................................ 1

. Background and Introduction............................................................................................................ 1 II. AdministrativeRecord ............................................................................................................................... 1 Il. Facility Description..................................................................................................................................... 2 IV. PermitHistory............................................................................................................................................ 2 V. COMMENTS RECEIVED AND RESPONSES ............................................................................................... 2 RATIONALE ............................................................................................................................................................... 1 I. DISCHARGER .............................................................................................................................................. 1 II. PERMITSTATUS ......................................................................................................................................... 1

III. FACILITY DISCHARGES AND RECEIVING WATERS.................................................................................. 2 IV. APPLICABLE EFFLUENT LIMITATIONS GUIDELINES ............................................................................... 3 V. PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS .......................................................... 4 VI. HISTORICA L MONITORING AND INSPECTION ......................................................................................... 4 VI1. NEW PERMIT LIMITS AND MONITORING REQUIREMENTS ............................................................... 4 A. Outfall 101 ................................................................................................................................................. 4 B. InternalMonitoringPoint 103 ........................................................................................................... 11 C. InternalMonitoringPoint 107 ................................................................................................................. 12 D. Outfall 110 [Closed Mode Operationsonly] ......................................................................................... 13 E. Outfalls 116 and 117................................................................................................................................ 13 F. Outfal 1118 ............................................................................................................................................... 13 G. Additional Limitations, Monitoring Requirements and Conditions..................................................... 14 VIII. Water QualityBased Calculationsfor METALS AND TOXICS ............................................................... 16 Storm Water...................................................................................................................................................... 20 IX. BIOM ONITORING REQUIREMENTS, CHRONIC.................................................................................... 21 X. OTHER REQUIREM ENTS ........................................................................................................................... 22 XI. XIII. ANTIDEGRADA7T ON .......................................................................................................................... 23 XII. PERMIT DURATION .................................................................................................................................. 24 APPENDIX I ....................................................................................................................................................... 25 APPENDIX 2 ....................................................................................................................................................... 29 APPLICABLE EFFLUENT LIMITATIONS GUIDELINES......................................................................................... 29 APPENDIX 3 ....................................................................................................................................................... 32 PREVIOUS PERMIT LIMITS ................................................................................................................................. 32 APPENDIX 4 ....................................................................................................................................................... 36 HISTORICAL M ONITORING AND INSPECTION................................................................................................ 36 APPENDIX 5 ..................................................................................................................................................... 37 NEW PERMIT LIMITS AND MONITORING REQUIREMENTS .......................................................................... 37 APPENDIX 5b ..................................................................................................................................................... 38 New Permit LIM ITS ............................................................................................................................................ 38 Internal MonitoringPoint 107 ........................................................................................................................... 39 TNO026450.doc

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 1 of 2a PART I A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS

1. Outfall 101 TVA - Sequoyah Nuclear Plant is authorized to discharge process and non-process wastewater (condenser circulating water, essential raw cooling water, cooling tower blowdown, raw cooling water, low volume wastes, miscellaneous low volume wastes, including various facilities drains and sumps, A/C condensate, steam generator blowdown, high pressure fire protection water, regeneration wastes from condensate demineralizer and stormwater runoff) through Outfall 101 to the Tennessee River at mile 483.65. The discharge shall be limited and monitored by the permittee as specified below:

Feature Description : External Outfall, Number : 101 Monitoring: Effluent Gross, Season : All Year

. ....- ., .E,.. M W R Chlorine, total residual <= .1 mg/L Calculated Weekdays Daily Maximum Chlorine, total residual <= .1 mg/L Calculated Weekdays Monthly Average Flow, in conduit or thru treatment Report plant MgaVd Recorder Continuous Daily Maxim urn Flow, In conduit or thru treatment Report Mgal/d Calculated Daily Monthly Average plant Temperature, water deg. Report centigrade deg C Calculated Continuous Daily Maximum IC25 Static Renewal 7 Day Chronic Chrceriodaphnia 43.2 % Composite Monthly Minimum IC25 Static Renewal 7 Day Chronic Chrpimephales 43.2 % Composite Monthly Minimum Monitoring: Effluent Gross, Season : Winter Temp. diff. between samp. &

<= 5 deg C Calculated Continuous Daily Maximum upstrm deg. C Monitoring : Instream Monitoring, Season : All Year Temperature rate of change deg <= 2 deg C/hr Calculated Continuous Daily Maximum C/hr Temperature, water deg. 30.5 deg C Calculated Continuous Daily Maximum centigrade Monitoring : Instream Monitoring, Season : Summer Temp. diff. between samp. & <= 3 deg C Calculated Continuous Daily Maximum upstrm deg. C e Cluae Samples taken in compliance with the monitoring requirements specified above shall be taken as follows: flow - sampled at diffuser gate prior to entry to the Tennessee River; ambient temperature - from station 14 located at TN River mile 490.5 upstream of SQN; river temperature - river temperature, temperature rise and rate of temperature change shall be determined by numerical model.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 2 of Xtt few WET testing frequency and results reporting will be governed by the B/CTP. However, in order to effectively track WET monitoring monthly reporting shall continue. For monitoring periods when WET testing is not required by the approved B/CTP; monitoring not required (or MNR) shall be reported on the discharge monitoring reports (DMRs) or the electronic report (if being used) to reflect that monitoring is not required.

See Part III of this permit for further description of toxicity tests.

TRC analysis shall be performed within fifteen (15) minutes of sample collection.

The acceptance methods for analysis of TRC are any methods specified in Title 40 CFR, Part 136, as amended. The method detection level (MDL) for TRC shall not exceed 0.08 mg/L unless the permittee demonstrates that its MDL is higher. The permittee shall retain the documentation that justifies the higher MDL and have it available for review upon request. Under the renewed permit limits, reporting of TRC at less than 0.08 mg/L shall be interpreted to constitute compliance with the permit.

The following requirements also apply to discharges from Outfall 101:

a. 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.

b. Depth average measurements can be taken at a backup temperature monitor at the downstream end of the diffuser mixing zone (left bank Tennessee River Mile 483.4, Station 8) 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 at Station 14, at about. Tennessee River Mile 490.5 (ambient temperature) and at quarter points and mid-channel at 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.

c. 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.

d. 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

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 3 of Q*(.0c) downstream end of the mixing zone shall be determined as that computed by the numerical model at a depth of 5 feet.

e. 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 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.

f. The daily maximum 24-hour average river temperature is limited to 30.50C. Since the state's criteria makes exception for exceeding the value as a result of natural conditions, where the 24-hour average ambient temperature exceeds 29.40C and the plant is operated in helper mode the maximum temperature may exceed 30.50C. In no case shall the plant discharge cause the 1-hour average river temperature at the downstream edge of the mixing zone to exceed 33.90 C without the consent of the permitting authority.

g. The temperature rise is the difference between the 24-hour average ambient river temperature and the 24-hour average temperature at the downstream edge of the mixing zone. The 24-hour average temperature rise shall be limited to 3.0 C0 during the months of April through October. The 24-hour average temperature rise shall be limited to 5.0 Co during the months of November through March.

h. 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 average river flow, and current 15-minute values of 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 2 C° per hour.

During periods when the Essential Raw Cooling Water (ERCW) and/or Raw Cooling Water (RCW) systems are receiving applications of biocides, (oxidizing or non-oxidizing), chemical dispersants, or detoxicant chemical additives, the permittee shall implement the Biocide/Corrosion Treatment Plan (B/CTP), which was approved April 27, 2005, and all subsequent revisions as approved by the Division. The B/CTP [plan] for these activities describes the specific chemical additive, material feed rate, method detection level (MDL) for the active compound(s), and the allowable concentration and/or mass limits, and actions proposed to ensure compliance with established effluent limitations during application. The B/CTP refers to the NPDES permit for specific language associated with monitoring Total Residual Chlorine (TRC). Note: the term TRC will encompass all references to any oxidants (i.e. chlorine/bromine) in use at the SQN facility; therefore, the acronym 'TRO" may be used interchangeably. WET frequency and results reporting will be governed by the B/CTP. The permit table for Outfall 101 will state that WET testing frequency and results reporting will be governed by the B/CTP. However, in order to effectively track WET monitoring monthly, reporting shall continue. For monitoring periods when WET testing is not required by the approved B/CTP; monitoring not required, or "MNR" shall be reported on the discharge monitoring report (DMR) or the electronic report (if being used) to reflect that monitoring is not required.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 4 of ?189 Z9 '

j. Total Residual Chlorine shall be sampled downstream of the chlorine injection points but prior to mixing with any other waste streams. TRC shall be calculated for the diffuser discharge (Outfall 101) based on these analyses and the proportional flows of the Condenser Circulating Water (CCW), ERCW, and RCW systems to indicate whether permit limits may be in danger of being exceeded. This calculation is a simple dilution calculation to project the maximum amount of chlorine that could be present at the discharge. The calculation will not allow for the decay of residual chlorine. If the CCW system is to be chlorinated or chlorination of the ERCW and/or RCW system is to occur while none of the units are discharging flow from the CCW system (i.e. zero CCW pumps in service), the B/CTP shall be revised and submitted to the Division for approval prior to initiation of the changes.

k. Any substance, including radioactive materials, is of interest to our Agency if it has reasonable potential to exceed applicable water quality criteria. However, radioactive releases to the environment, notwithstanding point source discharges authorized via this permit, are not regulated under the Clean Water Act, but are instead regulated under the Nuclear Regulatory Commission (NRC) by Issuance of an Operating License.

Pertinent regulations are found under 10 CFR Part 20 and 10 CFR Part 50. Sequoyah Nuclear Plant effluents that may contain radioactive material are not addressed as part of the NPDES permitting process.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 5 of 0829 (241

2. Internal Monitoring Point (formerly Outfall) 103 TVA-Sequoyah Nuclear Plant is authorized to discharge wastewater from the Low Volume Waste Treatment Pond through an internal monitoring point, IMP1 03 discharges into the Diffuser Pond, which finally discharges through Outfall 101. Wastewater consists of condensate demineralizer (CONDI), turbine building sump, stormwater from IMP 107, essential raw cooling water, raw cooling water and storm water runoff.

This discharge shall be limited and monitored by the permittee as specified below:

Description : Internal Outfall, Number :103, Monitoring : Effluent Gross, Season : All Year Flow, in conduit or thru Report MgaI/d Totalizer Continuous Daily Maximum treatment plant Flow, in conduit or thru Report Mgal/d Totalizer Continuous Monthly Average treatment plant Oil & Grease 20 mg/L Grab Twice Every Daily Maximum Month Oil & Grease 15 mg/L Grab Twice Every Monthly Average Month Solids, total suspended 100 mg/L Grab Twice Every Daily Maximum Month Solids, total suspended 30 mg/L Grab Twice Every Monthly Average Month pH 9 SU Grab Three WeekPer Maximum pH >= 6 SU Grab Three WeekPer Minimum Samples taken in compliance with the monitoring requirements specified above shall be taken at the following locations: low volume treatment pond discharge prior to mixing with other waste streams.

In the event that the turbine building sump is discharged directly to the CCW channel or the yard drainage pond, TSS, Oil and Grease and pH'shall be monitored 5/Week.

3. Internal Monitoring Point (formerly Outfall) 107 TVA Sequoyah Nuclear Plant is authorized to discharge rain water from the defunct metal cleaning ponds into the Low Volume Waste Treatment Pond, (IMP103) which discharges into the Diffuser Pond (Outfallil). TVA will be allowed to direct rainwater that falls in the now defunct metal cleaning ponds to the Low Volume Waste Treatment Pond without any requirements to monitor the discharge at the defunct metal cleaning ponds (IMP107). TVA will put in place a procedure to ensure that no wastewater will be discharge to the metal cleaning ponds.

4. Outfall 110 TVA - Sequoyah Nuclear Plant is authorized to discharge backwash wastewater through Outfall 110, to the cooling channel and intake forebay. Note that Outfall 110 is not

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 6 of 28 29 (Ai,;*

normally used in day-to-day operations of the plant and effluent limitations and monitoring requirements are applicable only during periods of closed-mode operation. However, should conditions apply that require its use as the main discharge point in place of Outfall 101 the same requirements of Outfall 101 shall apply to Outfall 110.

5. Ouffall 116 and 117 TVA - Sequoyah Nuclear Plant is authorized to discharge backwash wastewater through Outfall 116 to the Tennessee River at mile 485.2 and through Outfall 117 to the Tennessee River at mile 484.85. There are no limits or monitoring requirements for these discharges.

6. Outfall 118 TVA - Sequoyah Nuclear Plant is authorized to discharge settling pond water and storm water runoff (only applicable when the pond is in service) through Outfall 118 to the intake forebay at Tennessee River mile 484.8.

These discharges shall be limited and monitored by the permittee as specified below:

Description External Outfall, Number : 118, Monitoring Effluent Gross, Season All Year Flow, in conduit or thru Report Mgal/d Estimate Once Per Daily Maximum treatment plant Batch Flow, In conduit or thru Report - Mgal/d Estimate Once Per Monthly Average treatment plant Batch Oxygen, dissolved (DO) >= 2 mg/L Grab Twice Every Minimum Week Solids, settleable <= 1 mLIL Grab Monthly Daily Maximum Solids, total suspended 100 mg/L Grab Twice Every Daily Maximum Week There shall be no discharge of floating scum, solids, oil sheen, visible foam, and other floating matter in other than trace amounts Samples taken in compliance with the monitoring requirements specified above shall be taken of a discharge from the settling pond prior to mixing with the Intake Forebay.

Grab samples shall be taken at these frequencies, including a grab sample taken immediately prior to termination of the batch discharge.

These effluent limitations and monitoring requirements only apply at times when this settling pond is in use as a settling basin for dredged sediment. Best Management Practices (BMP) shall be used to control runoff from the pond. Examples include vegetative cover, silt fences, and/or hay bales.

7. Additional monitoring requirements and conditions applicable to all Outfalls include:

a) Flow shall be reported in Million Gallons per Day (MGD)

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 7 of 28 Z9 b) No discharge of polychlorinated biphenyl compounds (PCB) is allowed under this permit.

c) There shall be no distinctly visible floating scum, solids, oil sheen, visible foam, and other floating matter discharged with the wastewater to the receiving stream. The wastewater discharge must not cause an objectionable color contrast in the receiving stream.

d) The wastewater discharge shall not contain pollutants in quantities that will be hazardous or otherwise detrimental to humans, livestock, wildlife, plant life, or fish and aquatic life in the receiving stream.

e) Sludge or any other material removed by any treatment works must be disposed of in a manner that prevents its entrance into or pollution of any surface or subsurface waters. Additionally, the disposal of such sludge or other material must be in compliance with the Tennessee Solid Waste Disposal Act, TCA 68-31-101 et seq. and the Tennessee Hazardous Waste Management Act, TCA 68-46-101 et seq.

f) Priority Pollutants will not be discharged in cooling tower blowdown in amounts that are detectable by analytical methods in 40 CFR Part 136.

Monitoring for the Priority Pollutants will not be required unless making application for new NPDES permit.

B. MONITORING PROCEDURES

1. Representative Sampling Samples and measurements taken in compliance with the monitoring requirements specified herein shall be representative of the volume and nature of the monitored discharge, and shall be taken after treatment and prior to mixing with uncontaminated storm water runoff or the receiving stream.

2. Sampling Frequency Where the permit requires sampling and monitoring of a particular effluent characteristic(s) at a frequency of less than once per day or daily, the permittee is precluded from marking the "No Discharge" block on the Discharge Monitoring Report if there has been any discharge from that particular outfall during the period which coincides with the required monitoring frequency, i.e. if the required monitoring frequency is once per month or 1/month, the monitoring period is one month, and if the discharge occurs during only one day in that period then the permittee must sample on that day and report the results of analyses accordingly.

3. Test Procedures

a. Test procedures for the analysis of pollutants shall conform to regulations published pursuant to Section 304 (h) of the Clean Water Act (the "Act"),

as amended, under which such procedures may be required.

b. Unless otherwise noted in the permit, all pollutant parameters shall be determined according to methods prescribed in Title 40, CFR, Part 136, as amended, and promulgated pursuant to Section 304 (h) of the Act.

c. The acceptable methods for analysis of TRC are any methods specified in Title 40, CFR Part 136. The method detection level (MDL) for TRC shall not exceed 0.05mg/L unless the permittee demonstrates that its

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 8 of .2KZ96*,f MDL is higher. The permittee shall retain the documentation that justifies the higher MDL, and shall have that documentation available for review upon request. In cases where the permit limit is less than the MDL, the reporting of TRC at less than the MDL shall be interpreted to constitute compliance with the permit limit.

4. Recording of Results For each measurement or sample taken pursuant to the requirements of this permit, the permittee shall record the following information:

a. The exact place, date and time of sampling;

b. The exact person(s) collecting samples;

c. The dates and times the analyses were performed;

d. The person(s) or laboratory that performed the analyses;

e. The analytical techniques or methods used, and;

f. The results of all required analyses.

5. Records Retention All records and information resulting from the monitoring activities required by this permit including all records of analyses performed and calibration and maintenance of instrumentation shall be retained for a minimum of three (3) years, or longer, if requested by the Division of Water Pollution Control.

C. DEFINITIONS The Daily Maximum Concentrationis a limitation on the average concentration, in milligrams per liter (mg/L), of the discharge during any calendar day. When a proportional-to-flow composite sampling device is used, the daily concentration is the concentration of that 24-hour composite; when other sampling means are used, the daily concentration is the arithmetic mean of the concentrations of equal volume samples collected during any calendar day or sampling period.

The Monthly Average Concentration, a limitation on the discharge concentration, in milligrams per liter (mg/L), is the arithmetic mean of all daily concentrations determined in a one-month period. For the purpose of this definition, a frequency of 2/Month is representative of 2 separate daily samples, each sample having been collected on a separate day during the monitoring period.

The Monthly Average Amount, a discharge limitation measured in pounds per day (lb/day), is the total amount of any pollutant in the discharge by weight during a calendar month divided by the number of days in the month that the production or commercial facility was operating. Where less than daily sampling is required by a permit, the monthly average amount shall be determined by the summation of all the measured daily discharges by weight divided by the number of days during the calendar month when the measurements were made. For the purpose of this definition, a frequency of 2/Month is representative of 2 separate daily samples, each sample having been collected on a separate day during the monitoring period.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 9 of 26'29Q0,,

The Daily Maximum Amount is a limitation measured in pounds per day (lb/day), on the total amount of any pollutant in the discharge by weight during any calendar day.

The Instantaneous Concentration is a limitation on the concentration, in milligrams per liter (mg/L), of any pollutant contained in the discharge determined from a grab sample taken at any point in time.

For the purpose of this permit a Totalizer is a device or meter that continuously measures and calculates (adds) total flows in gallons, million gallons, cubic feet, or some other unit of volume measurement.

For the purposes of this permit, a Composite Sample* for non-storm water discharges is a sample composed of equal aliquots collected at the rate of at least once per hour at regular time intervals over the period of discharge in a 24-hour period and combined into a single sample. A composite sample may also be a sample collected continuously over a period of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months at a rate proportional to the flow. (*Except for sampling associated with Biomonitoring; use procedures for sampling from EPA-821-R-02-013, or most current edition.)

Continuous Discharge: A routine release to the environment that occurs without interruption, except for infrequent shutdowns for maintenance, process changes, etc.

For the purpose of this permit a Recorder is a device that makes a graph or other automatic record of the stage, pressure, depth, velocity, or the movement or position of water controlling devices, usually as a function of time.

A Grab Sample, for the purposes of this permit, is defined as a single effluent sample of at least 100 milliliters collected over a period not exceeding 15 minutes. The sample(s) shall be collected at the period(s) most representative of the total discharge.

For the purpose of this permit, a CalendarDay is defined as any 24-hour period.

For the purpose of this permit, a Quarter is defined as any one of the following three month periods: January 1 through March 31, April 1 through June 30, July 1 through September 30, or October 1 through December 31.

For the purpose of this permit, Semi-annually means the same as nonce every six months." Measurements of the effluent characteristics concentrations may be made anytime during a 6 month period beginning from the issuance date of this permit so long as the second set of measurements for a given 12 month period are made approximately 6 months subsequent to that time, if feasible.

For the purpose of this permit, Annually is defined as a monitoring frequency of once every twelve (12) months beginning with the date of issuance of this permit so long as the following set of measurements for a given 12 month period are made approximately 12 months subsequent to that time.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 10 of 2 '

D. REPORTING

1. Monitoring Results Monitoring results shall be recorded monthly and submitted monthly using Discharge Monitoring Report (DMR) forms supplied by the Division of Water Pollution Control or comparable forms provided by the permittee, and approved by the Division of Water Pollution Control. Submittals shall be postmarked no later than 15 days after the completion of the reporting period. The top two copies of each report are to be submitted. A copy should be retained for the permittee's files. DMRs and any communication regarding compliance with the conditions of this permit must be sent to:

TENNESSEE DEPT. OF ENVIRONMENT & CONSERVATION DIVISION OF WATER POLLUTION CONTROL COMPLIANCE REVIEW SECTION 401 CHURCH STREET L & C ANNEX 6TH FLOOR NASHVILLE TN 37243-1534 The first DMR is due on the fifteenth of the month following permit effectiveness.

DMRs and any other information or report must be signed and certified by a responsible corporate officer as defined in 40 CFR 122.22, a general partner or proprietor, or a principal municipal executive officer or ranking elected official or his duly authorized representative. Such authorization must be submitted in writing and must explain the duties and responsibilities of the authorized representative.

The electronic submission of DMRs shall be accepted only if approved in writing by the division. For purposes of determining compliance with this permit, data submitted in electronic format is legally equivalent to data submitted on signed and certified DMR forms.

2. Additional Monitoring by Permittee If the permittee monitors any pollutant specifically limited by this permit more frequently than required at the location(s) designated, using approved analytical methods as specified herein, the results of such monitoring shall be included in the calculation and reporting of the values required in the DMR form. Such increased frequency shall also be indicated on the form.

3. Falsifying Reports Knowingly making any false statement on any report required by this permit may result in the imposition of criminal penalties as provided for in Section 309 of the Federal Water Pollution Control Act, as amended, and in Section 69-3-115 of the Tennessee Water Quality Control Act.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 11 of 2'29

4. Outlier Data Outlier data include analytical results that are probably false. The validity of results is based on operational knowledge and a properly implemented quality assurance program. False results may include laboratory artifacts, potential sample tampering, broken or suspect sample containers, sample contamination or similar demonstrated quality control flaw.

Outlier data are identified through a properly implemented quality assurance program, and according to ASTM standards (e.g. Grubbs Test, 'h' and 'k' statistics).

Furthermore, outliers should be verified, corrected, or removed, based on further inquiries into the matter. If an outlier was verified (through repeated testing and/or analysis), it should remain in the preliminary data set. If an outlier resulted from a transcription or similar clerical error, it should be corrected and subsequently reported.

Therefore, only if an outlier was associated with problems in the collection or analysis of the samples, and as such does not conform with the Guidelines Establishing Test Procedures for the Analysis of Pollutants (40 CFR §136), it can be removed from the data set and not reported on the Discharge Monitoring Report forms (DMRs).

Otherwise, all results (including monitoring of pollutants more frequently than required at the location(s) designated, using approved analytical methods as specified in the permit) should be included in the calculation and reporting of the values required in the DMR form. The permittee is encouraged to use "comment" section of the DMR form (or attach additional pages), in order to explain any potential outliers or dubious results.

E. SCHEDULE OF COMPLIANCE Full compliance and operational levels shall be attained from the effective date of this permit.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 12 of ?8W2-9 PART II A. GENERAL PROVISIONS

1. Duty to Reapply Permittee is not authorized to discharge after the expiration date of this permit. In order to receive authorization to discharge beyond the expiration date, the permittee shall submit such information and forms as are required to the Director of Water Pollution Control (the "Director") no later than 180 days prior to the expiration date. Such applications must be properly signed and certified.

2. Right of Entry The permittee shall allow the Director, the Regional Administrator of the U.S.

Environmental Protection Agency, or their authorized representatives, upon the presentation of credentials:

a. To enter upon the permittee's premises where an effluent source is located or where records are required to be kept under the terms and conditions of this permit, and at reasonable times to copy these records;

b. To inspect at reasonable times any monitoring equipment or method or any collection, treatment, pollution management, or discharge facilities required under this permit; and

c. To sample at reasonable times any discharge of pollutants.

3. Availability of Reports Except for data determined to be confidential under Section 308 of the Federal Water Pollution Control Act, as amended, all reports prepared in accordance with the terms of this permit shall be available for public inspection at the offices of the Division of Water Pollution Control. As required by the Federal Act, effluent data shall not be considered confidential.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 13 of ?2 9

4. Proper Operation and Maintenance QI-W

a. The permittee shall at all times properly operate and maintain all facilities and systems (and related appurtenances) for collection and treatment which are installed or used by the permittee to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance also includes adequate laboratory and process controls and appropriate quality assurance procedures. This provision requires the operation of backup or auxiliary facilities or similar systems, which are installed by a permittee only when the operation is necessary to achieve compliance with the conditions of the permit. Backup continuous pH and flow monitoring equipment are not required.

b. Dilution water shall not be added to comply with effluent requirements to achieve BCT, BPT, BAT and or other technology-based effluent limitations such as those in State of Tennessee Rule 1200-4-5-.03.

5. Treatment Facility Failure The permittee, in order to maintain compliance with this permit, shall control production, all discharges, or both, upon reduction, loss, or failure of the treatment facility, until the facility is restored or an alternative method of treatment is provided. This requirement applies in such situations as the reduction, loss, or failure of the primary source of power.

6. Property Rights The issuance of this permit does not convey any property rights in either real or personal property, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State, or local laws or regulations.

7. Severability The provisions of this permit are severable. If any provision of this permit due to any circumstance, is held invalid, then the application of such provision to other circumstances and to the remainder of this permit shall not be affected thereby.

8. Other Information If the permittee becomes aware that he failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to the Director, then he shall promptly submit such facts or information.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 14 of ?82-9 B. CHANGES AFFECTING THE PERMIT

1. Planned Changes The permittee shall give notice to the Director as soon as possible of any planned physical alterations or additions to the permitted facility. Notice is required only when:

a. The alteration or addition to a permitted facility may meet one of the criteria for determining whether a facility is a new source in 40 CFR 122.29(b); or

b. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged. This notification applies to pollutants which are subject neither to effluent limitations in the permit, nor to notification requirements under 40 CFR 122.42(a) (1).

2. Permit Modification, Revocation, or Termination

a. This permit may be modified, revoked and reissued, or terminated for cause as described in 40 CFR 122.62 and 122.64, Federal Register, Volume 49, No. 188 (Wednesday, September 26,1984), as amended.

b. The permittee shall furnish to the Director, within a reasonable time, any information which the Director may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit, or to determine compliance with this permit. The permittee shall also furnish to the Director, upon request, copies of records required to be kept by this permit.

c. If any applicable effluent standard or prohibition (including any schedule of compliance specified in such effluent standard or prohibition) is established for any toxic pollutant under Section 307(a) of the Federal Water Pollution Control Act, as amended, the Director shall modify or revoke and reissue the permit to conform to the prohibition or to the effluent standard, providing that the effluent standard is more stringent than the limitation in the permit on the toxic pollutant. The permittee shall comply with these effluent standards or prohibitions within the time provided in the regulations that establish these standards or prohibitions, even if the permit has not yet been modified or revoked and reissued to incorporate the requirement.

d. The filing of a request by the permittee for a modification, revocation, reissuance, termination, or notification of planned changes or anticipated noncompliance does not halt any permit condition.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 15 of W829

3. Change of Ownership This permit may be transferred to another party (provided there are neither modifications to the facility or its operations, nor any other changes which might affect the permit limits and conditions contained in the permit) by the permittee if:

a. The permittee notifies the Director of the proposed transfer at least 30 days in advance of the proposed transfer date;

b. The notice includes a written agreement between the existing and new permittee's containing a specified date for transfer of permit responsibility, coverage, and liability between them; and

c. The Director, within 30 days, does not notify the current permittee and the new permittee of his intent to modify, revoke or reissue, or terminate the permit and to require that a new application be filed rather than agreeing to the transfer of the permit.

Pursuant to the requirements of 40 CFR 122.61, concerning transfer of ownership, the permittee must provide the following information to the division in their formal notice of intent to transfer ownership: 1) the NPDES permit number of the subject permit; 2) the effective date of the proposed transfer; 3) the name and address of the transferor; 4) the name and address of the transferee; 5) the names of the responsible parties for both the transferor and transferee; 6) a statement that the transferee assumes responsibility for the subject NPDES permit; 7) a statement that the transferor relinquishes responsibility for the subject NPDES permit; 8) the signatures of the responsible parties for both the transferor and transferee pursuant to the requirements of 40 CFR 122.22(a), "Signatories to permit applications"; and, 9) a statement regarding any proposed modifications to the facility, its operations, or any other changes which might affect the permit limits and conditions contained in the permit.

4. Change of Mailing Address The permittee shall promptly provide to the Director written notice of any change of mailing address. In the absence of such notice the original address of the permittee will be assumed to be correct.

C. NONCOMPLIANCE

1. Effect of Noncompliance All discharges shall be consistent with the terms and conditions of this permit.

Any permit noncompliance constitutes a violation of applicable State and Federal laws

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 16 of 28 29C4'g and is grounds for enforcement action permit termination, permit modification, or denial of permit reissuance.

2. Reporting of Noncompliance

a. 24-Hour Reporting In the case of any noncompliance which could cause a threat to public drinking supplies, or any other discharge which could constitute a threat to human health or the environment, the required notice of non-compliance shall be provided to the Division of Water Pollution Control in the appropriate Environmental Assistance Center within 24-hours from the time the permittee becomes aware of the circumstances. (The Environmental Assistance Center should be contacted for names and phone numbers of environmental response personnel).

A written submission must be provided within five days of the time the permittee becomes aware of the circumstances unless this requirement is waived by the Director on a case-by-case basis. The permittee shall provide the Director with the following information:

i. A description of the discharge and cause of noncompliance; ii. The period of noncompliance, including exact dates and times or, if not corrected, the anticipated time the noncompliance is expected to continue; and iii. The steps being taken to reduce, eliminate, and prevent recurrence of the noncomplying discharge.

b. Scheduled Reporting For instances of noncompliance which are not reported under subparagraph 2.a.

above, the permittee shall report the noncompliance on the Discharge Monitoring Report. The report shall contain all information concerning the steps taken, or planned, to reduce, eliminate, and prevent recurrence of the violation and the anticipated time the violation is expected to continue.

3. Overflow

a. "OverfloW' means the discharge to land or water of wastes from any portion of the collection, transmission, or treatment system other than through permitted outfalls.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 17 of ?.29

b. Overflows are prohibited. owif

c. The permittee shall operate the collection system so as to avoid overflows. No new or additional flows shall be added upstream of any point in the collection system, which experiences chronic overflows (greater than 5 events per year) or would otherwise overload any portion of the system.

d. Unless there is specific enforcement action to the contrary, the permittee is relieved of this requirement after: 1) an authorized representative of the Commissioner of the Department of Environment and Conservation has approved an engineering report and construction plans and specifications prepared in accordance with accepted engineering practices for correction of the problem; 2) the correction work is underway; and 3) the cumulative, peak-design, flows potentially added from new connections and line extensions upstream of any chronic overflow point are less than or proportional to the amount of inflow and infiltration removal documented upstream of that point. The inflow and infiltration reduction must be measured by the permittee using practices that are customary in the environmental engineering field and reported in an attachment to a Monthly Operating Report submitted to the local TDEC Environmental Assistance Center. The data measurement period shall be sufficient to account for seasonal rainfall patterns and seasonal groundwater table elevations.

e. In the event that more than five (5) overflows have occurred from a single point in the collection system for reasons that may not warrant the self-imposed moratorium or completion of the actions identified in this paragraph, the permittee may request a meeting with the Division of Water Pollution Control EAC staff to petition for a waiver based on mitigating evidence.

4. Upset

a. "Upset' means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation.

b. An upset shall constitute an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the permittee demonstrates, through properly signed, contemporaneous operating logs, or other relevant evidence that:

i. An upset occurred and that the permittee can identify the cause(s) of the upset;

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page IS of 29"29 6W ii. The permitted facility was at the time being operated in a prudent and workman-like manner and in compliance with proper operation and maintenance procedures; iii. The permittee submitted information required under "Reporting of Noncompliance" within 24-hours of becoming aware of the upset (if this information is provided orally, a written submission must be provided within five days); and iv. The permittee complied with any remedial measures required under "Adverse lmpact.u

5. Adverse Impact The permittee shall take all reasonable steps to minimize any adverse impact to the waters of Tennessee resulting from noncompliance with this permit, including such accelerated or additional monitoring as necessary to determine the nature and impact of the noncomplying discharge. It shall not be a defense for the permittee in an enforcement action that it would have been necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit.

6. Bypass

a. "Bypass"is the intentional diversion of wastewater away from any portion of a treatment facility. "Severe property damage" means substantial physical damage to property, damage to the treatment facilities, which would cause them to become inoperable, or substantial and permanent loss of natural resources, which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production.

b. Bypasses are prohibited unless the following 3 conditions are met:

iL The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage; ii. There are not feasible alternatives to bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment down time. This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass, which occurred during normal periods of equipment down time or preventative maintenance;

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 19 of ,29"29 iii. The permittee submits notice of an unanticipated bypass to the Division of Water Pollution Control in the appropriate environmental assistance center within 24-hours of becoming aware of the bypass (if this information is provided orally, a written submission must be provided within five days). When the need for the bypass is foreseeable, prior notification shall be submitted to the Director, if possible, at least 10 days before the date of the bypass.

c. Bypasses not exceeding limitations are allowed only if the bypass is necessary for essential maintenance to assure efficient operation. All other bypasses are prohibited. Allowable bypasses not exceeding limitations are not subject to the reporting requirements of 6.b.iii, above.

D. LIABILITIES

1. Civil and Criminal Liability Except as provided in permit conditions for "Bypassing," "Overflow," and "Upset," nothing in this permit shall be construed to relieve the permittee from civil or criminal penalties for noncompliance. Notwithstanding this permit, the permittee shall remain liable for any damages sustained by the State of Tennessee, including but not limited to fish kills and losses of aquatic life and/or wildlife, as a result of the discharge of wastewater to any surface or subsurface waters. Additionally, notwithstanding this Permit, it shall be the responsibility of the permittee to conduct its wastewater treatment and/or discharge activities in a manner such that public or private nuisances or health hazards will not be created.

2. Liability Under State Law Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties established pursuant to any applicable State law or the Federal Water Pollution Control Act, as amended.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 20 of 28 29 PART III Q(V OTHER REQUIREMENTS A. TOXIC POLLUTANTS The permittee shall notify the Division of Water Pollution Control as soon as it knows or has reason to believe:

1. That any activity has occurred or will occur which would result in the discharge on a routine or frequent basis, of any toxic substance(s) (listed at 40 CFR 122, Appendix D, Table II and III) which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels":

a. One hundred micrograms per liter (100 ug/);

b. Two hundred micrograms per liter (200 ug/l) for acrolein and acrylonitrile; five hundred micrograms per liter (500 ug/) for 2,4-dinitrophenol and for 2-methyl-4,6-dinitrophenol; and one milligram per liter (1 mg/L) for antimony;

c. Five (5) times the maximum concentration value reported for that pollutant(s) in the permit application in accordance with 122.21 (g) (7); or

d. The level established by the Director in accordance with 122.44(f).

2. That any activity has occurred or will occur which would result in any discharge, on a non-routine or infrequent basis, of a toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels":

a. Five hundred micrograms per liter (500 ug/l);

b. One milligram per liter (1 mg/L) for antimony;

c. Ten (10) times the maximum concentration value reported for that pollutant in the permit application in accordance with 122.21(g)(7); or

d. The level established by the Director in accordance with 122.44(f).

B. REOPENER CLAUSE If an applicable standard or limitation is promulgated under Sections 301(b) (2)

(C) and (D), 304(B) (2), and 307(a) (2) and that effluent standard or limitation is more stringent than any effluent limitation in the permit or controls a pollutant not limited in the permit, the permit shall be promptly modified or revoked and reissued to conform to that effluent standard or limitation.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 21 of ?2"29 C. PLACEMENT OF SIGNS Within sixty (60) days of the effective date of this permit, the permittee shall place and maintain a sign(s) at each outfall and any bypass/overflow point in the collection system. For the purposes of this requirement, any bypass/overflow point that has discharged five (5) or more times in the last year must be so posted. The sign(s) should be clearly visible to the public from the bank and the receiving stream or from the nearest public property/right-of-way, if applicable. The minimum sign size should be two feet by two feet (2' x 2') with one inch (1") letters. The sign should be made of durable material and have a white background with black letters.

The sign(s) are to provide notice to the public as to the nature of the discharge and, in the case of the permitted outfalls, that the discharge is regulated by the Tennessee Department of Environment and Conservation, Division of Water Pollution Control. The following is given as an example of the minimal amount of information that must be included on the sign:

TREATED INDUSTRIAL WASTEWATER TVA - Sequoyah Nuclear Plant (Permittee's Phone Number)

NPDES Permit NO. TN0026450 TENNESSEE DIVISION OF WATER POLLUTION CONTROL 1-888-891-8332 CHATTANOOGA-ENVIRONMENTAL FIELD OFFICE INDUSTRIAL STORM WATER RUNOFF TVA - Sequoyah Nuclear Plant (Permittee's Phone Number)

NPDES Permit NO. TN0026450 TENNESSEE DIVISION OF WATER POLLUTION CONTROL 1-888-891-8332 CHATTANOOGA-ENVIRONMENTAL FIELD OFFICE D. ANTIDEGRADATION Pursuant to the Rules of the Tennessee Department of Environment and Conservation, Chapter 1200-4-3-.06, titled 'Tennessee Antidegradation Statement," and in consideration of the Department's directive in attaining the greatest degree of effluent reduction achievable in municipal, industrial, and other wastes, the permittee shall further be required, pursuant to the terms and conditions of this permit, to comply with the effluent limitations and schedules of compliance required to implement applicable water quality standards, to comply with a State Water Quality Plan or other State or Federal laws or regulations, or where practicable, to comply with a standard permitting no discharge of pollutants.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 22 of ?A829 E. BIOMONITORING REQUIREMENTS, CHRONIC The permittee shall conduct a 3-Brood Ceriodaphnia dubia Survival and Reproduction Test and a 7-Day Fathead Minnow (Pimephalespromelas) Larval Survival and Growth Test on samples of final effluent from Outfall 101. Sampling shall be representative of the discharges made. The permittee shall try to arrange some samples for the biomonitoring testing to coincide with the intermittent application of chemicals so that there are toxicity test results that reflect seasonal variations in chemical treatments.

The measured endpoint for toxicity shall be the inhibition concentration causing 25% reduction (IC25) in survival, reproduction, or growth of the test organisms. The IC25 shall be determined based on a 25% reduction as compared to the controls. The average reproduction and growth responses shall be determined based on the number of Ceriodaphnia dubia or Pimephales promelas larvae used to initiate the test. A separate statistical analysis based on survival information is not required.

Test shall be conducted and its results reported based on appropriate replicates of a total of five serial dilutions and a control, using the percent effluent dilutions as presented in the following table:

Serial Dilutions for Whole Effluent Toxicity (WET) Testing 100% (100+PL)/2 Monitoring 0.50 X ML 025 X ML Control Effluent Limit (ML)

% effluent 100 86.4 43.2 21.6 10.8 0 The dilution/control water used will be moderately hard water as described in Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receivinq Waters to Freshwater Organisms, EPA-821-R-02-013 (or the most current edition).

Results from a chronic standard reference toxicant quality assurance test for each species tested shall be submitted with the discharge monitoring report. Reference toxicant tests shall be conducted as required in EPA-821-R-02-013 (or the most current edition). Additionally, the analysis of this multi-concentration test shall include review of the concentration-response relationship to ensure that calculated test results are interpreted appropriately.

Toxicity will be demonstrated if the IC25 is less than the monitoring limit indicated for each outfall in the above table(s). Toxicity demonstrated by the tests specified herein will serve as a hard trigger for accelerated biomonitoring. However, if raw water intake samples (tested concurrently with the effluent samples) are shown to be toxic enough to represent a test failure (100 percent samples statistically less than controls using t-tests and minnow growth or daphnia reproduction is 25 percent less than controls) and if effluent toxicity is not statistically greater than calculated intake toxicity, the effluent toxicity test in question will be considered invalid. In the event these two above described conditions occur, the toxicity test shall be repeated according to the schedule

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 23 of R8 O29W' requirements for test failure. Effluent toxicity that is not consistent with the intake toxicity conditions specified above will serve as a hard trigger for accelerated biomonitoring.

All tests will be conducted using a minimum of three 24-hour flow-proportionate composite samples of final effluent (e.g., collected on days 1, 3 and 5). If, in any control more than 20% of the test organisms die in 7 days, the test (control and effluent) is considered invalid and the test shall be repeated within 30 days of the date the initial test is invalidated. Furthermore, if the results do not meet the acceptability criteria of section 4.9.1, EPA-821-R-02-013 (or the most current edition), or if the required concentration-response review fails to yield a valid relationship per guidance contained in Method Guidance and Recommendations for Whole Effluent Toxicity (WET) Testing, EPA-821-B-00-004 (or the most current edition), that test shall be repeated. Any test initiated but terminated before completion must also be reported along with a complete explanation for the termination.

The toxicity tests specified herein for Outfall 101 shall be conducted according to the B/CTP and begin during the first chemical application requiring biomonitoring following the effective date of this permit. WET frequency and results reporting will be governed by the B/CTP. However, in order to effectively track WET monitoring, monthly reporting shall continue. For monitoring periods when WET testing is not required by the approved B/CTP, monitoring not required, or "MNR" shall be reported on the discharge monitoring report (DMR) or electronic report (if being used) to reflect that monitoring is not required.

In the event of a test failure, the permittee must start a follow-up test within 2 weeks and submit results from a follow-up test within 30 days from obtaining initial WET testing results. The follow-up test must be conducted using the same serial dilutions as presented in the corresponding table(s) above. The follow-up test will not negate an initial failed test. In addition, the failure of a follow-up test will constitute a hard trigger for accelerated blomonltoring, which must also be reported.

In the event of 2 consecutive test failures or 3 test failures within a 12-month period for the same outfall, the permittee must initiate a Toxicity Identification Evaluation/Toxicity Reduction Evaluation (TIE/TRE) study within 30 days and so notify the division by letter. This notification shall include a schedule of activities for the initial investigation of that outfall. During the term of the TIE/TRE study, the frequency of blomonltorlng shall be once every three months. Additionally, the permittee shall submit progress reports once every three months throughout the term of the TIE/TRE study. The toxicity must be reduced to allowable limits for that outfall within 2 years of initiation of the TIE/ITRE study. Subsequent to the results obtained from the TIE/TRE studies, the permittee may request an extension of the TIE/TRE study period if necessary to conduct further analyses. The final determination of any extension period will be made at the discretion of the division.

The TIE/TRE study may be terminated at any time upon the completion and submission of 2 consecutive tests (for the same outfall) demonstrating compliance.

Following the completion of TIE/TRE study, the frequency of monitoring will return to a

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 24 of 26 regular schedule, as defined previously in this section as well in Part I of the permit.

During the course of the TIE/TRE study, the permittee will continue to conduct toxicity testing of the outfall being investigated at the frequency of once every three months but will not be required to perform follow-up tests for that outfall during the period of TIEITRE study.

Test procedures, quality assurance practices, determinations of effluent survival/reproduction and survival/growth values, and report formats will be made in accordance with Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013, or the most current edition.

Results of all tests, reference toxicant information, copies of raw data sheets, statistical analysis and chemical analyses shall be compiled in a report. The report will be written in accordance with Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013, or the most current edition.

Two copies of biomonitoring reports (including follow-up reports) shall be submitted to the division. One copy of the report shall be submitted along with the discharge monitoring report (DMR). The second copy shall be submitted to the local Division of Water Pollution Control office address:

Chattanooga-Environmental Field Office Division of Water Pollution Control 540 McCallie Avenue, Suite 550 Chattanooga, TN 37402-2013 F. STUDIES RELATED TO EVALUATION OF CWA SECTION 316 Studies as outlined below shall be conducted by the permittee to confirm the performance of the SQN monitoring system and to verify that Section 316 of the Clean Water Act is being adequately met. The data from the studies shall be compiled with past data and reported to the Division of Water Pollution Control with a request for continuation of the thermal variance in the next permit application.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 25 of 9Z29 Section 316(a) QW('

(The variance for this requirementwill be public noticed with the permit.)

a. For Section 316(a), the permittee shall analyze previous and new data to determine whether significant changes have occurred in plant operation, reservoir operation or instream biology that would necessitate the need for changes in the thermal variance. The Reservoir Fish Assemblage Index will be used to annually assess the overall health of the fish community in Chickamauga Reservoir. If the fish community or particular populations fall significantly below expectations, further investigations will be proposed, and upon approval by the Division of Water Pollution Control, initiated to verify apparent declines and assist in the identification of possible sources of impairment.

b. To determine the adequacy of the measurement for ambient river temperature, TVA shall conduct field surveys of the river temperature for low river flow, as recommended in TVA Report No. WR2009-1-45-151. Specifically, field surveys shall be conducted if TVA finds it necessary to operate the river in a steady manner below a daily average flow of about 6000 cfs past the plant, or if TVA finds it necessary to operate the river in an unsteady manner below a daily average flow past the plant of about 13000 cfs. This is for operation of both units at SQN. For the operation of one unit at SQN, the limiting river flows for such surveys shall be 3000 cfs and 6500 cfs for steady river flow and unsteady river flow, respectively. Surveys are not required for low flow events where there are no units in operation at SQN. If TVA operates consistently above these levels, no field surveys are required. Also, if an event requires reducing the river flow below these levels without adequate advance notice (e.g., emergency situation),

the field surveys should be conducted at the earliest opportunity, in consideration of safe boating conditions and the time required in mobilizing staff and equipment. River flow data to demonstrate compliance to these conditions shall be submitted with the application for re-issuance of the permit. The results of any such surveys, if required, shall be provided to the Division within 90 days of completion of the survey.

c. To determine the adequacy of the diffuser mixing zone, TVA shall conduct field surveys of the river temperature for low river flow, as recommended in TVA Report No. WR2009-1-45-151. Specifically, field surveys shall be conducted if TVA finds it necessary to operate the river in a steady manner below a daily average flow of about 6000 cfs past the plant, or if TVA finds it necessary to operate the river in an unsteady manner below a daily average flow past the plant of about 10000 cfs. This is for operation of both units at SQN. For the operation of one unit at SQN, the limiting river flows for such surveys shall be 3000 cfs and 5000 cfs for steady river flow and unsteady river flow, respectively.

Surveys are not required for low flow events where there are no units in operation at SQN. If TVA operates consistently above these levels, no field surveys are required. Also, if an event requires reducing the river flow below these levels without adequate advance notice (e.g., emergency situation), the field surveys should be conducted at the earliest opportunity, in consideration of safe boating conditions and the time required mobilizing staff and equipment.

River flow data to demonstrate compliance to these conditions shall be submitted with the application for re-issuance of the permit. The results of any such surveys, if required, shall be provided to the Division within 90 days of completion of the survey.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 26 of 98"Z9cQ'g

2. Within 60 days of the permit effective date, the permittee shall prepare and submit for review by the Division a study plan which outlines how the permittee will conduct assessments that will generate information sufficient to support a determination of whether the Sequoyah Nuclear Plant's alternative thermal limit under Section 316(a) can be continued in its next NPDES permit. The proposed study plan shall be designed to supplement information previously provided by the permittee. The permittee shall implement provisions of the plan within 60 days of its approval by the Division.

3. Section 316(b)

a. Remaining 316(b) requirements for this facility are determined to be in compliance based on best professional judgment in accordance with 40 CFR 401.14 and 122.43. This permit may be reopened to address new 316(b) compliance requirements upon issuance of a new rule or final guidance by EPA.

G. STUDY TO CONFIRM CALIBRATION OF NUMERICAL MODEL The numerical model used to determine compliance with the temperature requirements for Outfall 101 shall be the 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.

The permittee shall calibrate the flow rate characteristics through the diffusers on a schedule of at least once every two years. For this permit period, such calibration shall be coordinated with the evaluation of the numerical modeling.

H. DIESEL FUEL OIL INTERCEPTOR SYSTEM As previously requested by TVA in February 2006, to close out the monitoring requirements associated with the diesel fuel oil interceptor system; TDEC concurs that the diesel fuel oil recovery project can be terminated. This project has been successful in recovering spilled diesel fuel that leaked out onto the ground. Results from the past two years show results at non-detectable or very low levels. TVA can terminate this recovery project at the end of 2010.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 27 of 26 2-9 PART IV STORM WATER POLLUTION PREVENTION PLAN AND BIOCIDEICORROSION TREATMENT PLAN A. STORM WATER POLLUTION PREVENTION PLAN Storm water runoff associated with industrial activity that is not discharged to the receiving stream through outfalls permitted in Part I of this permit is currently authorized under the Tennessee Storm Water Multi-Sector General permit for Industrial Activities (TMSP), Permit Number TNR050015. The TMSP requires development, implementation, and routine evaluation and updating of a storm water pollution prevention plan (SWPPP). The permittee shall also ensure that appropriate pollution prevention measures are identified in the SWPPP to minimize the discharge of pollutants in storm water or from ancillary activities via those outfalls described in Part I. Any necessary plan modifications shall be completed in accordance with the schedules set forth in the TMSP.

The discharger will develop, document and maintain a storm water pollution prevention plan (SWPPP) pursuant to the requirements as set forth in the Tennessee Multi-Sector General Permit for Industrial Activities, Sector 0, "Storm Water Discharges Associated With Industrial Activity From Steam Electric Power Generating Facilities", Part 3, "Storm Water Pollution Prevention Plan Requirements", as included in the Attachment I of this permit. Also found at: htto://www.state.tn.us/environment/wpc/stormh2o/pmt-o.pdf. The plan shall be signed by either a principal executive officer of a corporation, the owner or proprietor of a sole proprietorship, or a partner or general partner of a partnership.

B. BIOCIDE/CORROSION TREATMENT PLAN (B/CTP)

Previous permits addressed biocide and slimicide use at the site for process and non-process flows in the BMP program. A new program for managing the use of these products has been developed under the Biocide/Corrosion Treatment Plan (B/CTP). The permittee shall not conduct treatments of intake or process waters under this permit using biocides, dispersants, surfactants, corrosion inhibiting chemicals, or detoxification chemicals except in accordance with conditions specified under the written B/CTP [plan], which has been given prior approval on April 27, 2005, or subsequent revisions that are approved by the Division of Water Pollution Control. WET frequency and results reporting will be governed by the B/CTP.

C. DOCUMENTATION The permittee shall maintain the SWPPP and the B/CTP plans at the facility and shall make the plans available to the permit issuing authority upon request.

D. SWPPP-B/CTP PLAN MODIFICATION The permittee shall amend the SWPPP or B/CTP plan(s) plan whenever there is a change in the facility or change in the operation of the facility that materially increases the potential for the ancillary activities to result in a discharge of significant amounts of pollutants.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 28 of aB A9 E. MODIFICATION FOR INEFFECTIVENESS 0" If the SWPPP or B/CTP plan(s) prove(s) to be ineffective in achieving the general objective of preventing the release of significant amounts of pollutants to surface waters and the specific objectives and requirements under section B, the permit shall be subject to modification pursuant to 40 CFR 122.62 or 122.63 to incorporate revised SWPPP or B/CTP requirements. Any such permit modification shall be subject to review in accordance with the procedures for permit appeals set forth in accordance with 69 110, Tennessee Code Annotated.

F. COMPLIANCE SCHEDULE The SWPPP and B/CTP plan shall be maintained and the permittee shall begin implementation of any updates of the plan within six (6) months-after the effective date of this permit.

TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page 29 of a2.9 ATTACHMENT I Sector 0 - Storm Water Discharges Associated With Industrial Activity From Steam Electric Power Generating Facilities. Including Coal Handling Areas Found at:

http://www.state.tn.us/environment/wpc/stormh2o/pmt-o.pdf

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 1 of AR - 7 ADDENDUM TO RATIONALE with Record of Comments and Responses National Pollutant Discharge Elimination System TVA Sequoyah Nuclear Plant, Soddy Daisy, TN NPDES Permit No. TN0026450 1 February 2011 I. Background and Introduction On January 27, 2009, the Tennessee Valley Authority (TVA) submitted an application for an NPDES Permit for the discharge of effluent from the Sequoyah Nuclear Plant in Soddy Daisy, TN. The TN Department of Environment and Conservation (TDEC),

Division of Water Pollution Control (the division) published a draft permit TN0026450 for the facility on October 11, 2010. Also, the division issued a public notice on the availability of the draft permit for public review and for a public hearing to be held in Chattanooga, TN. The hearing was held on November 10, 2010, and was followed by a comment period through December 10, 2010.

This Addendum to Rationale addresses comments submitted during the public notice period. It also presents TDEC's decision regarding the permit and rationale for that decision.

Comments are shown below with TDECs response and proposed permit changes, as applicable. Written comments are, for the most part, shown verbatim. Lengthy comments have been paraphrased from multiple-page comments which included background and spreadsheets of data. The full length documents are available for review on request. Comments are shown in plain text with responses shown In bold text.

II. Administrative Record This Addendum to Rationale (or fact sheet) dated December, 2010, sets forth the division's basis for permit conditions to be applied for the issuance of the Tennessee NPDES permit for the facility discharge. The permit authorizes a point source discharge to waters of the State of Tennessee from the facility.

On October 14, 2010, the division issued Public Hearing Notice PH10-18, which announced a public hearing, conducted at the TDEC Chattanooga Environmental Field Office in Chattanooga, TN on Wednesday, November 10, 2010, at 6 p.m. (EST).

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 2 of AR - 7 On October 11, 20109 the division issued Public Notice #MMIX-019, which announced its intent to issue the permit. The draft permit was made available in an electronic format on the division's web site at http://www.state.tn.us/environment/wpc/wpcppo/.

The NPDES permit was drafted in accordance with the provisions of the Federal Water Pollution Control Act, the Tennessee Water Quality Control Act, and other applicable standards and regulations.

IlI. Facility Description TVA - Sequoyah Nuclear Plant discharges approximately 20 MGD from a retention pond into the Tennessee River at mile 100 via the Diffuser Pond. The plant has two units with a generating capacity of 1,485 megawatts.

IV. Permit History Permit was last issued in November, 2007, and expired in July 28, 2009 with an administrative extension for current coverage of daily operations at the Sequoyah Nuclear Plant.

This Addendum to Rationale contains all Information obtained during the public review of the Draft Permit, including additional comments by the public and reviewing agencies, suggestions and calculations applicable to the proposed discharge.

V. COMMENTS RECEIVED AND RESPONSES General Several Commenters suggested changes to the previous Rationale. The Rationale portion of a permit is not edited after public notice has occurred because the Rationale defines the basis for permit conditions at the time of that writing. The Rationale is not legally binding but is an informational document.

Comments suggesting changes to the Permit of a grammatical, typographical, and informational nature are made in the final permit, but are not repeated herein.

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 3 of AR - 7 Comment 1:

1. Page 1 of 29, Outfall 101 monitoring requirements:

a. TVA requests that the effluent limits for Total Residual Chlorine (TRC) remain at the current NPDES Permit limit of 0.10 mg/L. Enclosed is a copy of SQN Biocide/Corrosion Treatment Plan Approval and B/CTP Request for Approval submitted to TDEC in March 2005, requesting an NPDES Permit limit of 0.10 mg/L for TRC. TVA's request was based on results from the onsite chlorine demand study which established the method of detection for TRC at 0.08 mg/ L for the SQN site. Also enclosed is a copy of TDEC July 30, 2004, approval for Watts Bar Nuclear's (WBN) Biocide/Corrosion Treatment Plan which established a 0.10 mg/L TRC permit limit for WBN. As previously discussed with your staff, a review of historical samples taken internal to the plant system and calculated for Outfall 101 since 1996 illustrates that the effluent concentrations comply with the allowable water quality based limits.

Response

TDEC agrees to retain for Outfall 101 the TRC limit of 0.1 mg/l per the previous permit. This limit conforms to previous TDEC approval in 2005 of the B/CTP for both SQN and WBN.

Comment 2:

TVA request that TDEC add for clarification the following information as footnote 1 for Outfall 101. Samples taken in compliance with the monitoring requirements specified above shall be taken as follows:

" Flow - sampled at diffuser gate prior to entry to the Tennessee River;

Ambient Temperature from Station 14 located at Tennessee River Mile 490.5 upstream of SQN;

" River Temperature - river temperature, temperature rise, and rate of temperature change shall be determined by numerical model.

Response

Clarification of these sampling locations has been made on Page 2 of 29 for the footnote of Outfall 101 limits table.

Comment 3:

Page 3 of 29, Outfall 101 monitoring requirements: TVA requests that the last paragraph on this page be changed to read as:

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 4 of AR - 7 Any substance, including radioactive materials, is of interest to our Agency if it has reasonable potential to exceed applicable water quality criteria. However, radioactive releases to the environment, notwithstanding point source discharges authorized via this permit, are not regulated under the Clean Water Act, but are instead regulated under the Nuclear Regulatory Commission (NRC) by Issuance of an Operating License. Pertinent regulations are found under 10 CFR Part 20 and 10 CFR Part 50. Sequoyah Nuclear Plant effluents that may contain radioactive material are not addressed as part of the NPDES permitting process.

Response: Clarification of monitoring requirements per this comment is added to Page 3 of 29, Outfall 101.

Comment 4: Suaqqested Changes to Rationale Response: Because the Rationale establishes the basis for permit conditions at the time of that writing, the Rationale remains unchanged In the administrative record. Subsequent clarifications or comments to the Rationale are addressed In this Addendum as supporting information for issuance of the renewed permit.

Shown below are TDEC clarifications to these suggested changes as it relates to whether changes are made in the permit.

1. Page R-5 of R-43, Outfall 101 monitoring requirements: TVA requests that the last paragraph on this page be changed to read as:

Any substance, including radioactive materials, is of interest to our Agency if it has reasonable potential to exceed applicable water quality criteria. However, radioactive releases to the environment, notwithstanding point source discharges authorized via this permit, are not regulated under the Clean Water Act, but are instead regulated under the Nuclear Regulatory Commission (NRC) by issuance of an Operating License. Pertinent regulations are found under 10 CFR Part 20 and 10 CFR Part 50. Sequoyah Nuclear Plant effluents that may contain radioactive material are not addressed as part of the NPDES permitting process.

See above Response to comment 3.

2. Page R-8 of R-43, Outfall 101 monitoring requirements: TVA requests that the last sentence in Section e. on Polychlorinated Biphenyls (PCB) paragraph be changed to match the permit pages for Outfall 101 and to read as:

PCB monitoring at Outfall 101 will be deleted from the monitoring requirements.

The permit does not require PCB monitoring at Outfall 101.

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 5 of AR - 7

3. Page R-8 of R-43, Outfall 101 monitoring requirements: TVA requests that the effluent limits for Total Residual Chlorine (TRC) remain at the current NPDES Permit limit of 0.10 mg/L. As stated on the Rationale page R-8 of R-43, the Lower Limit of Quantification (LLD) for the colorimetric analysis of chlorine using DPD indicator are extremely variable and dependent upon the sample matrix.

TVA has performed extensive LLD studies for chlorine analysis using EPA-approved analytical methodologies and associated instrumentation. SQN has determined that the LLD for the Tennessee River in the vicinity of SQN is 0.08 mg/L. TVA had this study independently confirmed by Watts Bar Nuclear Plant.

Although the 0.1 mg/L effluent limit will exceed the criterion maximum concentration (CMC), it is recognized that the reported values provided by TVA are calculated value based on TRC measurements taken within a small system prior to mixing with the total cooling water flow. TVA's calculated value only takes into account the mixing with the large volume of non-chlorinated cooling water and does not taken into account the dissipation due to elevated temperatures of the water, sunlight, or turbulence of the water prior to being discharged from Outfall 101. With all of these factors included, TVA is providing a very conservative TRC calculated value for Outfall 101. Therefore, it is anticipated that an effluent limit of 0.10 mg/L for TRC will comply with water quality criteria.

See Comment 101 - The revised permit limit table for Outfall 101 limits TRC to 0.1 mg/L - see page 2 of the permit.

Comment 5 regarding Thermal Variance After examining the record of prior 316(a) variance determinations for the Sequoyah Plant, EPA has concerns regarding the need for a more thorough examination and definition of the Balanced and Indigenous Population (BIP), the identification of Representative Important Species (RISs), and a closer examination of whether the variance is protective. Given the thinness of the available record for prior variance determinations, EPA believes a more focused study is needed. EPA acknowledges that TVA has in the past collected a substantial amount of data in support of its variance. TVA may use existing data in completing its next study and may incorporate the existence of such data into a CWA Section 316(a) Study Plan design; however, the existing data needs to be evaluated and presented in the context of a BIP definition that the existing record does not adequately provide.

To reiterate, in order to ensure that TVA's Study Plan is adequate to demonstrate that the Sequoyah Plant should get continuance of a Section CWA 316(a) variance during the term of its next NPDES permit, EPA requests the opportunity to review a draft CWA 316(a) study plan prior to TVA commencing the study Response: The renewed permit requires TVA to submit a Study Plan within 60 days of the permit effective date. TDEC will ensure that EPA review and approval is requested prior to TDEC approval of the Study Plan.

Comment 6:

1. The permit fact should explain the changes in the monitoring location to internal monitoring point 103 for some of the parameters.

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 6 of AR - 7 Response: Internal Monitoring Point 103 conveys low volume wastes (which are subject to Effluent Limitations Guidelines) into the higher flow diffuser pond which is primarily cooling water. Monitoring for compliance at IMP 003 enables both TDEC and the permittee to document compliance with ELGs prior to significant dilution with cooling water.

Comment 7:

2. The permit fact sheet should better explain the language in the permit regarding justification for eliminating the monitoring for boron.

Response: The draft permit inadvertently included boron in the table of effluent limits for Outfall 101. As noted in the rationale, neither the DMR monitoring data since 2000 nor the analyses submitted with the permit application have detected the presence of boron at the RDL of 0.2 mg/Il.

Comment 8:

3. The permit should clarify in item 3 on page 4 that "this permit prohibits the discharge of metal cleaning waste."

AND

5. The fact sheet says that there will be no discharge of metal cleaning waste from internal outfall 103. Therefore, TDEC should delete "Treated Metal Cleaning Waste" from the description for Outfall 103. Otherwise, you will need to include the effluent guideline limits for metal cleaning waste.

Response: In the permit, the description atop the table with effluent limits has been revised to delete Metal cleaning wastes.

Comment 9:

4. The reasonable potential analyses should done for all metals.

Response: The permit application indicated detectable concentrations In Outfall 101 for the following metals (for which TN has relevant water quality criteria):

arsenic, copper, mercury. A revised spreadsheet for reasonable potential analysis Is attached to this Addendum.

Addendum to Rationale - December 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page AR- 7 of AR - 7 WATER QUALITY BASED EFFLUENT CALCULATIONS OUTFALL 101 FACILITY: Sequoyah Neclear Plant PERMIT#: TN0026450 Stream Stream Waste Tit.Susp. Hardness Siream (1010) (3005) ROw Solids Ias CaCO3) Allocation 3MGD3 74GD]00

[MGD] 1L im0 5 %]

3483.0 7740.0 11509.6 1 101 50 90 1 2 3 4 5 6 1 7 1 a Stream FisWAqua. Life Effluent Fish & ruati0Ute Waterslt, Crtera M (1020)

Bckgmd. Water 9uality Criteria Fraction kr-Stream Allowabe Ceic. Efuent Concentration EFFLUENT Conr. (Chronic Acute Dissoled Chronic Acute Chronic Acute CHARACTERISTIC lug] [ug! [ug] [Fraction] MA I [g/i

[u11 [ugil I lugs]

Chlorine fr. Res.) 0.0 11.0 19.0 1.0 11.0 19.0 32.74 56.55 Arsenic 1.350 150 340 1.0 150 340 443.67 1009.21 Copper 2.40 4.95 6.99 0.35 14.25 20.12 37.43 54.91 Mercury, (T) 0.005 0.770 1.400 1.000 0.770 1.400 228 4.16 9 10 1 11 1 112 1 13 1 14 Human Health Water Quality Criteria (30Q2)

In-Stream Criteria Calc. Effluent Concentration EFFLUENT Organisms _Vater/Organism DWS Organisms later/Organism DWS CHARACTERISTIC jlug/l] lug/] aug/i] lug/l lugil] lug/]

Chlorine (T. Res.) NA NA NA NA NA NA Arsenic

10.0 10.0 10.0 151 151 151 Copper j NA NA NA NA NA NA Mercury,T* 0.051 0.05 2.0 0.3 0.3 7.5 Criteria for this criteria is expressed as dissolved.

Denotes metals for Which Fish& Aquatic Life Criteria are espressed as a function of total hardness.

The Fish & Aquatic Life criteria for this metal are in the dissolved form at laboratory conditions.

NOTE: Water Quality criteria for stream use classifications other than Fish & Aquatic Life are based on the 3005 flow.

Rationale - September 2010 -- TVA- Sequoyah Nuclear Plant NPDES # TN0026450 Page R- 1 of R - 41 RATIONALE TVA - Sequoyah Nuclear Plant NPDES PERMIT NO. TN0026450 Soddy Daisy, Hamilton County, Tennessee Permit Writer: Mr. Bob Alexander September, 2010 I. DISCHARGER TVA - Sequoyah Nuclear Plant SB-2A, Sequoyah Access Road, P 0 BOX 2000 Soddy Daisy, Hamilton County, Tennessee Contact Person:

Stephanie Howard, Environmental Manager - SON and WBN 423-843-6700 Nature of Business:

Production of electric power by thermonuclear fission and other associated operations.

SIC Code(s): 4911 (Electric Services)

Industrial Classification: Primary [PRIMARY INDUSTRY CATEGORY means any Industry category listed In the NRDC Settlement Agreement (Natural Resources Defense Council v. Train, 8 ERC 2120 [D.D.C. 1976], modified 12 ERC 1833 [D.D.C. 1979]).]

Discharger Rating: Major PERMIT STATUS NPDES Permit No. TN0026450 issued 11130/07 NPDES Permit No. TN0026450 expired 07/28/09 Application for Renewal received at:

CH-EFO, 1/29/09; NCO, 2/4109 Watershed Scheduling Environmental Field Office: Chattanooga Primary Longitude: 85-05-14 Primary Latitude: 35-12-35 Hydrocode: 6020001 Watershed Group: 3 Watershed Identification: Tennessee River (Hamilton Co. Except Chattanooga)

Target Watershed Evaluation Date: 2013

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-2 of R-41 III. FACILITY DISCHARGES AND RECEIVING WATERS TVA - Sequoyah Nuclear Plant discharges process and non-process wastewaters through Outfalls 101, IMP103, IMP107, 110,116,117 and 118 to Tennessee River. Appendix 1 summarizes facility discharges and receiving stream information for all outfalls.

The Tennessee Multi-Sector General Storm Water Permit TNR050015 covers storm water discharges associated with industrial activity of this facility. Storm water concerns associated with this facility are covered in this general permit, so they will not be addressed in detail in the individual NPDES permit.

The Chickamauga Reservoir portion of the Tennessee River is considered to be fully supportina all designated uses shown in Appendix 1. Biological data submitted by TVA with the permit application addresses the condition of the fishery in Chickamauga Lake. These data are discussed below as part of the analyses of thermal effects of cooling water discharges.

Flow is regulated in the Tennessee River by upstream operations of Watts Bar Dam at mile 529.9 and, therefore, the TDEC rule at 1200-4-3.05 require application of the minimum critical low flow based on the 1Q10 recurrence interval. The 1Q10 used in the previous permit was 5400 cfs or 3491 MGD.

Information was provided with the permit application addressing changes in TVA Reservoir Operations which were implemented during the previous permit term. These changes were addressed and are summarized in the Reservoir Operations EIS', which established:

" Bi-weekly average flow, June through August of 13,000 cfs.

Bi-weekly average flow, May and September of 7,000 cfs.

" Daily Average flow, October through April of 3,000 cfs.

Updates to the policy are summarized in the TVA letter describing existing operations policies as attached to the permit application2 . Significant points regarding flow through Chickamauga Dam* are:

" For upstream tributary reservoir flow volume above the minimum operating guide, weekly average minimum flow increases June 1 from 14,000 cfs to 25,000 by August 1.

" From August to Labor Day (1st week of September), weekly average minimum flow is 29,000 cfs.

" For reservoir volume below the guide, weekly average minimum flow from June to August is 13,000 cfs.

" From August to Labor Day, the weekly average minimum flow is 25,000 cfs.

River flows as low as 6,000 cfs in November 2007 are identified in the 2009 TVA Report, which was required by the previous permit 3. This flow value occurred during a record-setting 1TVA, ProgrammaticEIS, TVA Reservoir OperationsStudy, Record of Decision, May 2004, Appendix A, pg A-5, available at http://www.tva.gov/environinent/reports/roseis/ros_rod.pdf.

2 TVA letter to Stefanie Howard, SQN, from Charles L. Bach, GM, River Scheduling, TVA River Operations, January 7, 2009.

3 TVA, Ambient Temperature and Mixing Zone Studies .for Sequoyah Nuclear Plant, WR2009-1-45-151, Preparedby Hopping, Stewart, Montgomery, and Higgins, Knoxville, TN, January 2009.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-3 of R-41 drought and is considered by TDEC as comparable to the 1Q10 low flow value used in the previous permit.

The only significant difference in river flow from Watts Bar Dam and Chickamauga Dam is due to Hiwassee River flow, which is approx. 670 cfs, or 433 MGD.

Note on Radiological Discharges:

Effluent discharges authorized through an NPDES program can not cause condition of pollution, nor a discharge of toxics in toxic amounts can be authorized. Any substance, including radioactive materials, is of interest to our agency if it has reasonable potential to exceed applicable water quality criteria. However, radioactive releases to the environment, notwithstanding point source discharges authorized via this permit, are not regulated under the Clean Water Act, but are instead regulated under the Nuclear Regulatory Commission (NRC) by issuance of an Operating License. Pertinent regulations are found under 10 CFR Part 20 and 10 CFR Part 50. Sequoyah Nuclear Plant effluents that may contain radioactive material are not addressed as part of the NPDES permitting process.

IV. APPLICABLE EFFLUENT LIMITATIONS GUIDELINES The Standard Industrial Classification (SIC) code for TVA - Sequoyah Nuclear Plant is 4911 (Electric Services). Process wastewater discharged through Outfall 101 is regulated by 40 CFR Part §423.12(b) (3)-BPT, and 40 CFR Part §423.13(d) (1)-BAT. Appendix 2 lists the applicable best available technology (BAT) and best conventional pollution control technology (BCT) effluent limitations guidelines. Certain variances are included in the permit to comply with Section 316(a) of the Clean Water Act.

EPA is currently drafting revised ELGs for steam electric plants and issued a proposed Information Collection Request (ICR) questionaire on March 9, 2010.4 o ICR was distributed in mid-2010 to selected fossil plants o Responses from fossil plants were due in 60 days o EPA analyses of the data will follow, with draft ELGs planned for 2012 o Final ELGs are planned to be proposed in 2014.

For detailed information and to see the questionaire, see Fact Sheet: Request for Comment on Questionnaire for the Steam Electric Power Generatina Effluent Guidelines (February 2010). A relevant excerpt is quoted below:

"Approximately 734 fossil- or nuclear-fueled steam electric plants will be required to complete Parts A and I of the questionnaire. This total includes approximately 495 coal-fired, 9 petroleum coke-fired, 20 oil-fired, 168 gas-fired, 20 nuclear power plants, and 22 combination power plants. [...] One or more of these subpopulations will also be required to fill out certain additional detailed sections (for some sections of the questionnaire, the coal-fired respondents will be reduced to a subset of approximately 94 plants).

EPA has determined that the data obtained through the Steam Electric ICR is necessary for EPA to review and revise the ELGs for the steam electric industry. The ICR will obtain information about steam electric power generating industry operations for use in characterizing

.4 75 FR 10791, March 9, 2010

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-4 of R-41 waste streams and the processes that generate the wastes, environmental data, and the availability and affordability of technologies that may be used to reduce wastewater pollutant discharges associated with this industry. These data will be used to perform detailed technical and economic analyses that will support EPA's potential development of numerical limitations or best management practices for wastewaters generated by steam electric plants."5 [emphasis added].

V. PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS Appendix 3 lists the permit limitations and monitoring requirements as defined in the previous permit.

Previous permit terms related to compliance with CWA Section 316 included submission of biological monitoring data by January 2008. These data were to be collected in accordance with the permittee's Proposal for Information Collection (PIC) plan, developed in 2005 under the 316(b) requirements prior to their suspension by EPA on March 20, 2007.

Additional background and detailed discussion of thermal conditions and permit limits are provided below in Sec. VII New Permit Limits - Outfall 101 Effluent Temperature.

VI. HISTORICAL MONITORING AND INSPECTION During the previous permit term there were no reported violations of the applicable effluent limitations. Data reported by TVA - Sequoyah Nuclear Plant on Discharge Monitoring Report forms during the previous permit term is summarized in Appendix 4.

Division field personnel performed a recent (2006) Compliance Evaluation Inspection (CEI) at the facility however, no notable issues were revealed.

VII. NEW PERMIT LIMITS AND MONITORING REQUIREMENTS The proposed new permit limits have been selected by determining technology-based limits, then evaluating whether those limits protect the water quality of the receiving stream. If the technology-based limit would cause violations of water quality, then the water quality-based limit is chosen. The technology-based limit is determined from EPA effluent limitations guidelines if applicable (see Part IV); or from State of Tennessee effluent limits for effluent limited segments per Rule 1200-4-5-.03(2); or by way of operational and/or treatability data.

Note that in general, the term "anti-backsliding" refers to a statutory provision that prohibits the renewal, reissuance, or modification of an existing NPDES permit that contains effluents limits, permit conditions, or standards that are less stringent than those established in the previous permit.

Appendix 5 lists the proposed effluent limitations and monitoring requirements for all outfalls to be included in the new permit.

A. Outfall 101 Outfall 101 is the largest volume discharge from the TVA-SQN facility that is primarily composed of once through cooling waters. It also contains water from internal monitoring points (IMP) 103 and 107, and storm water runoff from the site. When the plant is operating in open 5 See EPA Supporting Statement; supra note 8 at 1-2.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-5 of R-41 mode, the discharge volume will be more than a billion gallons per day. Discharge is by gravity feed to the two diffusers from the diffuser pond. The diffuser pond does not have a significant holding capacity for the discharges and the residence time for water in the pond is relatively short (several hours).

a. Flow Flow shall be reported in Million Gallons per Day (MGD). Monitoring of flow quantifies the load of pollutants to the stream. The flow shall be continuously monitored and recorded, and reported on the monthly discharge report (DMR).

b. Oil and Grease The limits for Oil and Grease per 40 CFR 423 (15 mg/I Monthly Average and 20 mg/I Daily Maximum) are applied here to meet the monitoring and compliance standards for low volume wastes. A review of data for Oil and Grease at Outfalll01 for the past 14 years shows a maximum of 10.0 mg/L and a median value of < 5.0 mg/L. TVA also monitors Oil and Grease from the Low Volume Waste Pond (IMP103). To comply with antibacksliding provisions, IMP103 will become the primary monitoring and compliance point for Oil & Grease. Oil and Grease monitoring at Outfalll01 will be deleted from the permit requirements.

c. Total Suspended Solids ('SS1 The limits for Total Suspended Solids (TSS) per 40 CFR 423 (30 mg/I Monthly Average and 100 mg/I Daily Maximum) are applied here to meet the monitoring and compliance standards for low volume wastes. A review of data for TSS at Outfalll01 for the past 14 years shows a maximum of 38.0 mg/L and a median value of 5.0 mg/L. TVA also monitors TSS from the Low Volume Waste Pond (IMP103). To comply with antibacksliding provisions, IMP103 will become the primary monitoring and compliance point for TSS. TSS monitoring at Outfalll01 will be deleted from the permit requirements.

d. PH According to the State of Tennessee Water Quality Standards [Chapter 1200 3-.03(3) (b)], the pH for the protection of Fish and Aquatic Life shall lie within the range of 6.5 to 9.0 and shall not fluctuate more than 1.0 unit in this range over a period of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . A review of data for pH at Outfalll01 for the past 14 years shows a maximum of 8.5 S.U. and a median value of 7.6 S.U. TVA also monitors pH from the Low Volume Waste Pond (IMP103). To comply with antibacksliding provisions, IMP103 will become the primary monitoring and compliance point for pH. pH monitoring at Outfalll01 will be deleted from the permit requirements. The previous permit limits of 6.0 to 9.0 are retained at IMP103 and were taken from EPA's Effluent Limitation Guidelines 40 CFR Part 423.

e. Polychlorinated Biphenvis EPA's Effluent Limitation Guidelines in 40 CFR Part 423 requires that there shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid. Therefore, NO DISCHARGE of PCBs will be allowed. A review

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-6 of R-41 of data for PCB at Outfalll01 for the past 11 years shows values below 0.0005 mgIL, which is the Required Detection Level per TDEC rules. PCB monitoring at Outfalll01 will be revised to require reporting once per permit cycle by grab sample.

f. Total Residual Chlorine Technology-based (BAT) limits of 0.2 mg/L monthly average and 0.5 mg/L daily maximum limits apply to free available chlorine in cooling tower blowdown in accordance with 40 CFR, part 423, Subpart 423.13 (b) (1). The total residual chlorine (TRC) test includes all chlorine species measured in the free available chlorine test as well as other chlorine compounds such as chloramines. Thus the permit writer retains the TRC test in place of the free available chlorine test for compliance with the 40 CFR limitations.

Water quality limits of 0.04 mg/L monthly average and 0.06 mg/L daily maximum for total chlorine residual are calculated to protect water quality as shown in Appendix 5a based on the discharge flow of Outfall 101, 1509.6 MGD. The limits are based on the protection of water quality in the Tennessee River to meet published WQC of 0.011 monthly average and 0.019 mg/I daily maximum.

A review of data for TRC values at Outfalll01 during the previous permit shows an average concentration of 0.018 mg/L and a maximum of 0.056 mg/L. Accordingly, the renewed permit will establish the monthly average limit of 0.04 mg/L and the daily maximum limit of 0.06 mg/L for Total Residual Chlorine (TRC).

With the permit application, TVA submitted:

The Lower Limit of Quantification (LLD)for the colorimetricanalysis of chlorine using DPD indicatorare extremely variable and dependent upon the sample matrix. Typically, a more pure matrix results in a lower LLD because less interference is present. Instrument manufactures typically report a "best case " LLD in their specification by using a distilled water matrixfor LLD determination. However, this LLD cannot be achieved in more complex matrices such as river water due to the presence of organic compounds and color which both negatively impact analyticalsensitivity.

Sequoyah has performed extensive LLD studiesfor chlorine analysis using EPA-approvedanalyticalmethodologies and associatedinstrumentation.

Sequoyah has determined that the LLD for Tennessee is 0.08 mg/L. This study was independently confirmed by Watts Bar Nuclear Plant.

The acceptable methods for analysis of TRC are any methods specified in Title 40 CFR, Part 136, as amended. The method detection level (MDL) for TRC shall not exceed 0.08 mg/I, unless the permittee demonstrates that its MDL is higher. The permittee shall retain the documentation that justifies the higher MDL and have it available for review upon request. Under the renewed permit limits, reporting of TRC at less than 0.08 mg/I shall be interpreted to constitute compliance with the permit.

g. Boron. Total (as B)

The division has reviewed the permit application and DMR data submitted since 2000 and has confirmed that Boron is not detected in the effluent. Accordingly, boron monitoring at Outfalll01 will be deleted from the permit requirements.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-7 of R-41

h. Compliance with Section 316, Clean Water Act

1. 316(a) Potential Thermal Effects on a Balanced Indigenous Population Thermal discharges are a concern for potential effects on a balanced and indigenous population of fish and other aquatic organisms at this location. TVA's extensive studies to date will be further expanded under EPA's guidance during this permit cycle. EPA Region IV has indicated that additional aquatic data should be collected during the five-year duration of the subject permit to facilitate the Section 316(a) determination in the "next NPDES permit." (Permit III.L.) The renewed permit retains the alternative thermal limit as existing data demonstrate the maintenance of a balanced indigenous population ("BIP") in the receiving water body. TVA will be required to submit a study plan outlining proposed assessments to support continuance of the ATL. The plan will be designed to supplement existing information previously provided by TVA. EPA has agreed to this approach and will participate in the review of the plan and the resulting data.

Section 316(a) of the Clean Water Act allows point-source discharges of heated water to exceed State water quality thermal criteria based on demonstrating maintenance of "Balanced Indigenous Populations" (BIP) of aquatic life. SQN is operating under a 316(a) alternate thermal variance that has been administratively continued with each permit renewal based on studies conducted in the 1980's. The requirement for conducting 316(a) studies in TN comes from EPA Region IVguidance to the States requiring future variance requests be granted on new data generated to show aquatic communities meet the BIP standard.

In 2001, TDEC approved the TVA program for Reservoir Fish Assemblies Index (RFAI) studies to support the continuation of thermal variances. RFAI data is collected at upstream and downstream stations in Chickamauga Lake every year. With the application, TVA submitted data from 2000 through 2009 supporting their request for continuation of the 316(a) variance from the previous permit.

With the permit renewal application of January 2009, TVA described ecological conditions near SQN as monitored at three locations under their Vital Signs (VS) program, inflow, transition and forebay. In addition to the fish community, environmental indicators are measured in the VS program for dissolved oxygen, chlorophyll, sediment quality, and benthic macro-invertebrate community.

TDEC has reviewed the RFAI fish community data for 2000-2009 and identified no substantial difference in the fish community of the Chickamauga Reservoir between fish upstream and downstream of SQN. Fish data for both the upstream and downstream stations were determined similar and meet the BIP standard.

Extensive interagency discussions between TVA, TDEC, and EPA Region 4 have occurred regarding future studies to demonstrate BIP. EPA Region 4 has requested additional information prior to their approval of TDEC renewal of any NPDES permits for steam electric power plants, in order to evaluate the thermal component and protection and propagation of a BIP. EPA and TVA have agreed to revise the existing TVA process for reservoir monitoring in accordance with the following terms:

Within 60 days of the permit effective date, the permittee shall prepare and submit for review by the Division a study plan which outlines how the permittee will conduct assessments that

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-8 of R-41 will generate information sufficient to support a determination of whether the Sequoyah Nuclear Plant's alternative thermal limit under Section 316(a) can be continued in its next NPDES permit. The proposed study plan shall be designed to supplement information previously provided by the permittee. The permittee shall implement provisions of the plan within 60 days of its approvalby the Division In the renewed permit, TDEC will extend the thermal variance, with the condition that TVA will revise the reservoir monitoring approach acceptable to TDEC and EPA Region 4.

2. Thermal Limits and Monitoring Requirements This permit requires compliance with TN effluent temperature criteria except for the months of November through March when a variance is allowed for upstream to downstream rise in temperature to be as great as 5 Co. Otherwise, temperature shall be limited according to the State of Tennessee Water Quality Standards for the protection of Fish & Aquatic Life

[Chapter 1200-4-3-.03(3) (e)]. It is recognized that the temperature of the cooling water discharge will be greater than the temperature of the water prior to its use for cooling or other purposes. This discharge shall not cause the temperature change in receiving stream to exceed 30C relative to an upstream control point for the months of April through October. Also, this discharge shall not cause the temperature of receiving stream to exceed 30.50C (except as a result of natural causes), and this discharge shall not cause the maximum rate of temperature change in receiving stream to exceed 2°C per hour; except as a result of natural causes.

The calculated and measured temperatures of the effluent are reported on the monthly Discharge Monitoring Reports (DMRs). The temperature difference, rate of change, and receiving stream calculated-temperatures, shall also be limited and reported on the DMR's.

The measured, reported, temperature of the effluent is not limited as such, and an exceedances of the above mentioned 30.50C water quality criteria will not be considered a permit violation for measured effluent temperature. The 30.50 C value applies to the receiving stream, not the effluent. When background stream temperatures are warm and approach 30.50C as a result of natural conditions the division understands that the plant is then operated in Helper Mode. Helper Mode is defined as: full operation of one cooling tower and at least three lift pumps per operating unit. The permit maximum of 30.50C may be exceeded when the instream temperatures exceed 29.40C and the plant operates in Helper Mode. In no circumstance shall a one-hour average maximum downstream river temperature exceed 33.90C without consent of the permitting authority. The division shall be notified by phone, facsimile, and/or electronic mail as soon as possible (within 12-hours of calculating these conditions) should these conditions present themselves. Compliance with the 30.50C maximum limit shall be determined from the 24-hour average.

The 24-hour average temperature rise in the receiving stream shall be calculated by taking measurements continuously (continuously is defined as measurements taken in 15 minute or less intervals). The 24-hour average value shall be determined using the current and previous ninety-six 15-minute measurements. Thus, every 15 minutes a 24-hour average value shall be calculated. The maximum of the ninety-six observations generated per day by this procedure shall be the daily maximum temperature rise for that day.

Instream river temperatures shall be averaged every 15 minutes in similar fashion to give a "rolling" 24-hour average. To determine compliance with the instream maximum limit of 30.50C and the temperature difference between upstream and downstream temperatures, the 24-hour average shall be used.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-9 of R-41 Tennessee Rule 1200-4-3-.05 applies to temperature monitoring by including protection of the water quality in the mixing zone.

"Mixing Zone - Mixing zone refers to that section of a flowing stream or impounded waters in the immediate vicinity of an outfall where an effluent becomes dispersed and mixed. Such zones shall be restricted in area and length and shall not (i) prevent the free passage of fish or cause aquatic life mortality in the receiving waters; (ii)contain materials in concentrations that exceed recognized acute toxicity levels for biota representative of the aquatic community in the receiving waters; (iii) result in offensive conditions; (iv) produce undesirable aquatic life or result in dominance of a nuisance species; (v) endanger the public health or welfare; or (vi) adversely affect the reasonable and necessary uses of the area; (vii) create a condition of chronic toxicity beyond the edge of the mixing zone; and (viii) adversely affect nursery and spawning areas."

The mixing zone was established in the initial EPA-issued permit (April 1, 1983), and as defined, has been retained in Tennessee's reissuance of the permit. The definition of the mixing zone for the new permit is continued from the previous permit for the discharge at Outfall 101, which encompasses 1500 feet downstream of the diffusers to 275 feet upstream of the diffusers and 750 feet wide. Depth of the mixing zone includes the entire depth of the reservoir on the downstream side of the diffusers. On the upstream side of the diffusers the mixing zone extends in depth from the surface 275 feet upstream of the diffusers to the top of the diffuser pipes. The initial mixing zone also included the intake forebay and diffuser pond when the plant operated in closed mode. The diffuser pond is not recognized as waters of the State, instead is considered part of the treatment system and therefore, is not part of the mixing zone for permit purposes. The intake forebay is recognized as waters of the State, but shall be included in the mixing zone only in circumstances when the plant operates in closed mode.

The intake forebay connects to the river through openings at the bottom of the skimmer wall.

In closed mode operation relatively little water is coming through the openings in the skimmer wall. Therefore, it makes sense to include the intake forebay in the mixing zone in these circumstances. TVA does not anticipate the operation of the plant in closed mode. However, if such emerges as a serious possibility, the monitoring requirements for the forebay shall be determined by appropriate study at that time.

The mixing zone is needed for two reasons. It allows mixing for the thermal loading of the effluent before water quality criteria must be met. For compliance purposes, it allows a well-defined area to be used for actual instream assessments.

TVA Report No. WR2009-1-45-151, required in the last permit cycle, provided a summary of data and studies that have been performed to validate the adequacy of the ambient temperature measurement and the adequacy of the mixing zone. As a part of this work, the location of the ambient temperature measurement had to be moved upstream from about Tennessee River Mile 484.7 to about Tennessee River Mile 490.5, due to the recirculation of plant effluent that occurs at low river flow. TVA shall continue to evaluate the adequacy of the ambient temperature measurement and the adequacy of the mixing zone, if it found necessary to reduce the river flow below levels summarized in Report No. WR2009 45-151.

When both units are operational, the difference between the upstream and downstream temperatures is usually between 3 and 4 Celsius degrees during the winter months. The maximum for data reported since January 2000 was 2.0°C. Since 2000, an instream-maximum temperature greater than 30.50C has only occurred only during the summer of 2010. In these events, no temperature violations were incurred because the plant was placed in helper mode with the operation of one cooling tower and three lift pumps per operating unit. Under these

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-10 of R-41 operating conditions, the maximum instream temperature may exceed 30.50C. During the drought of 2006-7, the highest reported receiving-stream temperature was less than 30.50 in summer.

Sampling of the effluent flow and temperature shall be continuous and shall be recorded for the DMR.

3. Cooling Water Intake Structure - Section 316(b) 316(b) requirements for this facility are determined to be in compliance based on best professional judgment in accordance with 40 CFR 401.14 and 122.43. As required by the previous permit, TVA submitted biological monitoring data collected in accordance with the permittee's Proposal for Information Collection (PIC) plan as developed under the 316(b) requirements prior to their suspension by EPA on March 20, 2007. This permit may be reopened to address new 316(b) compliance requirements upon issuance of a new rule or final guidance by EPA.

316(b) limitations for this facility are determined to be in compliance based on best professional judgment in accordance with 40 CFR 401.14 and 122.43. This permit may be reopened to address compliance with 316(b) requirements upon issuance of a new rule or final guidance by EPA.

This permit, TN00054110, had been previously issued by EPA under the federal NPDES permit program. In those previous permits the facility was deemed to be in compliance with the Clean Water Act Regulations, Establishing Requirements for Cooling Water Intake Structures at Phase II Existing Facilities. This regulation is also referred to as the "316(b) rule".

Previous and current compliance with the rule have been and continue to be based on best professional judgment (BPJ) in accordance with Title 40 CFR 401.14 and 122.43. In 2007, during review of the draft permit addressing TVA's request for permit modification of the 316(b) language, EPA Region 4 suggested the division add language to the rationale of the permit to better detail the events supporting this modification. As it is still relevant to this permit renewal, we have included background information regarding the 2007 recent Court actions relating to the 316(b) rule:

On February 16, 2004, EPA took final action on regulationsgoverning cooling water intake structures at certain existing power producingfacilities under section 316(b) of the Clean Water Act (PhaseHI rule). 69 FR 41576 (July 9, 2004). The final Phase H rule applies to existing facilities that are point sources that, as their primary activity, both generate and transmit electric power or generate electric power for sale to another entity for transmission; use or propose to use cooling water intake structures with a total design intakeflow of 50 MGD or more to withdraw cooling waterfrom waters of the United States; and use at least 25 percent of the water withdrawn exclusively for coolingpurposes (see 40 CFR 125.91).

Under the Phase 11 rule, EPA established performance standardsfor the reduction of impingement mortality and entrainment (see 40 CFR 125.94). The performance standards consist of ranges of reductions in impingement mortality and/or entrainment. These performance standards were determined to reflect the Best Technology Available (BTA) for minimizing adverse environmentalimpacts atfacilities covered by the PhaseHI rule.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-1 1 of R-41 These regulations were challenged by industry and environmental stakeholders.

On judicial review, the Second Circuit decision (Riverkeeper, Inc. v. EPA, 475 F.3d 83, (2d Cir., 2007)) remanded several provisions of the Phase II rule on various grounds. The provisions remanded to EPA include:

EPA's determinationof the BTA under section 316(b);

The rule'sperformance standardranges;

The cost-cost and cost-benefit compliance alternatives;

The Technology Installationand Operation Planprovision;

The restorationprovision;and

The "independent supplier" provision.

With several significantprovisionsof the PhaseII rule affected by the decision, and with the need to provide timely direction to Stakeholders about the continuing application of the Phase 11 rule, EPA's Assistant Administratorfor Water issued a memorandum on March 20, 2007, which announced EPA's intention to suspend the Phase II rule. This memorandum also discussed the anticipatedissuanceof[this] FederalRegister suspension document.

The formal suspension of the rule was published in the Federal Register: July 9, 2007 (Volume 72, Number 130)] [Rules and Regulations] [Page 3 7107-37109], and is availablefrom the FederalRegister Online via GPOAccess [wais.access.gpo.gov][DOCID.frO9jyO7-3].

Upon notice of the suspension of this rule, TVA requested to modify and remove only the suspended 316(b) requirements previously issued in this and seven (7) other TVA NPDES permits. The division agreed with the TVA request and modified only those requirements specifically suspended by the EPA, specifically the CDS report. All other permit requirements remained in place as enforceable compliance items as previously permitted and were deemed to remain in compliance with the remainder of the Clean Water Act based on BTA and best professional judgment (BPJ). In January, 2009, TVA submitted biological monitoring data collected in accordance with the permittee's Proposal for Information Collection (PIC) plan as developed under the 316(b) requirements prior to their suspension by EPA on March 20, 2007. This and other information will be used to support evaluation of Best Technology Available during permit reissuance in subsequent years.

B. Internal Monitoring Point 103 IMP103 is an internal sampling point representing discharges from the Low Volume Waste Treatment Pond (LVWTP), which includes pressure washing and vehicle washing.

Wastewater from the Essential Raw Cooling Water (ERCW) system, the Raw Cooling Water (RCW) system, the Lined Metal Cleaning Waste Pond, and the Turbine Building Sump also discharge into the LVWTP. The diffuser pond discharges pass through the diffusers through Outfall 101, into the Tennessee River. IMP103 will become the primary monitoring and compliance point for low volume waste.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-12 of R-41 Flow Flow shall be reported in Million Gallons per Day (MGD) and monitored at the time of sample collection. Monitoring of flow quantifies the load of pollutants to the stream. Flow will be recorded on a totalizer and reported 3 times per week.

Oil and Grease The limits for oil and grease in the new permit will be required by EPA's Effluent Limitation Guidelines (ELG) 40 CFR Part 423: 15 mg/I Monthly Average, 20 mg/I Daily Maximum. The ELG states: 'The quantity of pollutants discharged in the low volume waste sources shall not exceed the quantity determined by multiplying the flow of the low volume waste sources times the concentration listed in the [following] table." However to comply with antibacksliding provisions the previous permit limits will be retained.

Sampling will be twice per month by grab sample.

Total Susoended Solids (TSS)

The limits for TSS in the new permit will be required by EPA's Effluent Limitation Guidelines (ELG) 40 CFR Part 423: 30 mg/I Monthly Average, 100 mg/I Daily Maximum.

The ELG states: 'The quantity of pollutants discharged in the low volume waste sources shall not exceed the quantity determined by multiplying the flow of the low volume waste sources times the concentration listed in the [following] table." However to comply with antibacksliding provisions the previous permit limits will be retained. Sampling will be twice per month by grab sample.

According to the State of Tennessee Water Quality Standards [Chapter 1200 3-.03(3) (b)], the pH for the protection of Fish and Aquatic Life shall lie within the range of 6.5 to 9.0 and shall not fluctuate more than 1.0 unit in this range over a period of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The previous permit limits of 6.0 to 9.0 will be retained and were derived from EPA's Effluent Limitation Guidelines 40 CFR Part 423. The sample type will be grab and will be measured three times per week.

C. Internal Monitorling Point 107 IMP07 is an internal monitoring point to check compliance with permit limitations for the metal cleaning wastewaters which discharges to the Low Volume Waste Treatment pond (LVWTP). The LVWTP (Outfall 103) then discharges into the Diffuser Pond which discharges through Outfall 101 to the Tennessee River, and is monitored by parameters established for those discharged wastewaters.

The last metal cleaning wastewater discharged into IMP107 was in December 2001. Since that timeframe, IMP107 been discharged approximately 150 times due to rainfall.

A review of the monitoring data shows that TSS has averaged 3.5 mg/L since December 2001 with a maximum of 19.0 mg/L. Oil and Grease has averaged < 5.0 mg/L (e.g., detection limit) since December 2001 with a maximum of 6.2 mg/L. Copper has averaged 0.005 mg/L since December 2001 with a maximum of 0.023 mg/L. Iron has averaged 0.312 mg/L since December 2001 with a maximum of 1.0 mg/L on February 12, 2004. pH readings since December 2001 have had a median of 8.4 S.U. with a maximum pH value of 8.9 S.U.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-13 of R-41 TVA Sequoyah Nuclear Plant is authorized to discharge rain water from the defunct metal cleaning ponds into the Low Volume Waste Treatment Pond, (IMP103) which discharges into the Diffuser Pond (Outfalll01). TVA will be allowed to direct rainwater that falls in the now defunct metal cleaning ponds to the Low Volume Waste Treatment Pond without any requirements to monitor the discharge at the defunct metal cleaning ponds (IMP107). TVA will put in place a procedure to ensure that no wastewater will be discharged to the metal cleaning ponds.

D. Outfall 110 [Closed Mode Operations only]

As described in the permit application, a discharge from Outfall 110 occurs only when the power plant operates in closed mode operation, which is infrequent. Operation in closed mode has been precluded because of operational restrictions that happen when the plant is operated in this [closed] mode; discharge from Outfall 110 is not anticipated to occur. Closed mode operation is when condenser-circulating water is cooled in the cooling towers and is then routed, via the cold-water return channel, to the intake forebay. Outfall 110 is a sampling point for water passing from the channel into the forebay. The discharge would consist of non-contact cooling water, including primarily condenser circulating water, the essential raw cooling water, and raw cooling water. Other waters would be from the liquid radwaste system, regeneration wastes from the condensate demineralizer, and steam generator blowdown.

Outfall 110 will be limited with the same permit limitations established for Outfall 101 when operated in closed mode only. If discharge occurs, the permittee will monitor and report on the discharge using the same sampling and analysis protocol(s) established for Outfall 101.

When no discharge occurs, the permittee shall report "no discharge" on the Discharge Monitoring Report (DMR).

When the facility operates in closed mode, the mixing zone boundaries change to include the intake forebay. Mixing zone temperature compliance calculations only apply at Outfall 101, temperature will not be limited for Outfall 110 discharges.

E. Outfalls 116 and 117 These discharges result from backwashing wastewater from the screens and strainers of the water intake for Condenser Circulating Water (CCW), (Outfall 116) and the intake for Essential Raw Cooling Water (ERCW) (Outfall 117).

Previous permit conditions did not include numerical limitations or monitoring requirements, instead narrative requirements established that no materials were discharged except material previously present in the intake water, and that there shall be no visible sheen in the discharges.

Based on recurrent reports which do not indicate presence of pollutants in this backwash, monitoring will be deleted from the renewed permit.

F. Ouffall 118 This outfall drains the Essential Raw Cooling Water dredge pond. Presently the pond is not in service and discharges small amounts of storm water are coming from its now-vegetated area.

The previous outfall limitations were established for discharges from the pond when it was in service, including limits and monitoring for settleable solids, TSS and dissolved oxygen.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-14 of R-41 These limits became void after the pond was emptied of dredged water and vegetation established in the pond area.

The permit writer proposes that present permit limits be applied to discharges from the pond, if it is put back into service. Otherwise, no monitoring will be required. When no discharge occurs, the permittee shall report "no discharge" on the Discharge Monitoring Report (DMR).

G. Additional Limitations, Monitoring Requirements and Conditions In addition to the specific numerical limitations discussed above, there are a number of general requirements that will apply to outfalls 101, 110, 116, 117, and 118 and internal monitoring points IMP 103, and IMP 107. These requirements are discussed as follows:

40 CFR Part 423.12 (b) (2) (BPT) and Part 423.13 (a) (BAT) specify, "There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid." This requirement was in the previous permit and will be retained in the new permit.

ii. 40 CFR Part 423.12 (b) (8) (BPT requirements, non wastewater source specific) states that "Neither free available chlorine nor total residual chlorine may be discharged from any unit for more than two hours in any one day and not more than one unit in any plant may discharge free available chlorine or total residual chlorine at any one time unless the utility can demonstrate to the Regional Administrator or State, if the State has NPDES permit issuing authority, that the units in a particular location cannot operate at or below this level of chlorination."

iii. 40 CFR Part 423.13 (b) (2) (BAT requirements, specific to once through cooling water) also states that for plants with a rated electric generating capacity of 25 or more megawatts that 'Total residual chlorine may not be discharged from any single generating unit for more than two hours per day unless the discharger demonstrates to the permitting authority that discharge for more than two hours is required for macroinvertebrate control. Simultaneous multi-unit chlorination is permitted."

iv. 40 CFR Part 423.13 (d) (2) (BAT requirements, specific to cooling tower blowdown) states "Neither free available nor total residual chlorine may be discharged from any unit for more than two hours in any one day and not more than one unit in any plant may discharge free available or total residual chlorine at any one time unless the utility can demonstrate to the Regional Administrator or State, if the State has NPDES permit issuing authority, that the units in a particular location cannot operate at or below this level of chlorination."

These requirements are potentially applicable to Outfalls 101 (and Outfall 110 in Closed Mode). Chlorine is not added to the Condenser Circulating Water System (once through cooling water), or to the high-pressure fire protection system, (when flushed), at the Sequoyah Nuclear Plant who's discharge is

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-15 of R-41 primarily through Outfall 101. With regard to cooling tower blowdown, TVA has made a demonstration to the Division that the facility cannot operate the cooling towers under these requirements without significant damage to the system potentially jeopardizing operational safety. These requirements were not in the previous permit and will not be included in the new permit.

v. 40 CFR Part 423.13 (d) (1), BAT requirements for cooling tower blowdown, establishes monthly average and daily maximum effluent limitations for the 126 Priority Pollutants. The monthly average limit and the daily maximum limit (except for chromium and zinc) is "No Detectable Amount." However, Part 423.13 (d) (3) allows the permitting authority, at its discretion, to utilize engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by analytical methods in 40 CFR Part 136. This requirement is potentially applicable to outfall 101. TVA has provided data that demonstrates that priority pollutants will not be added to the system in quantities that will be detectable in cooling tower blowdown. Also the data provided with the Form 2C permit application indicates that the priority pollutants were not present in detectable amounts. The following general statement will be added to the permit "Priority Pollutants will not be discharged in cooling tower blowdown in amounts that are detectable by analytical methods in 40 CFR Part 136.

Monitoring for the Priority Pollutants will not be required."

vi. Bromine products may be used at times in the raw water system. For purposes of measurement of Total Residual Chlorine (TRC) in the permit, analyses shall include residual bromine with the results reported as chlorine. Thus there is no separate test for residual bromine, but one test for situations where combinations of chlorine and bromine are being used.

vii. It is recognized that the permittee must use biocides and corrosion inhibitor products to properly operate the facility. Because the chemicals in these products may be detrimental to fish and aquatic life in the receiving stream, there is a need to evaluate the nature of the chemicals, the dosage to be used, the duration of use, the effluent concentration, and the need for treatment prior to discharge. Previous permits addressed biocide/slimicide and corrosion inhibitor products use at the site for process and non-process flows in the BMP program.

A program for managing the use of these products has been developed under the Biocide/Corrosion Treatment Plan (B/CTP). The permittee shall not conduct treatments of intake or process waters under this permit using biocides, dispersants, surfactants, corrosion inhibiting chemicals, or detoxification chemicals except in accordance with conditions specified under the written B/CTP [plan], which has been given prior approval on April 27, 2005 (or other revisions), by the Division of Water Pollution Control. The mechanism to alter these applications is by formally amending the B/CTP.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-16 of R-41 VIII. Water Quality Based Calculations for METALS AND TOXICS The primary concern for aquatic toxicity from SQN discharges relates to use of blocides or oxidizers such as chlorine. The following procedure is used to calculate the allowable instream concentrations for metals and toxics permit limitations.

1, The most recent background conditions of the receiving stream segment for Outfall 101 were compiled using this information:

1Q10 of receiving stream (3491 MGD)

Calcium hardness (measured ambient data (50 mg/L))

Total suspended solids (10 mg/I, default)

Background metals concentrations (measured ambient data)

Other dischargers impacting this segment

Downstream water supplies, if applicable

2. The chronic water quality criteria are converted from total recoverable metal at lab conditions to dissolved lab conditions for the following metals: cadmium, copper, lead, nickel and zinc. Then translators are used to convert the dissolved lab conditions to total recoverable metal at ambient conditions.

3. The acute water quality criteria are converted from total recoverable metal at lab conditions to dissolved lab conditions for the following metals: cadmium, copper, lead, nickel, zinc, silver and mercury. Then translators are used to convert the dissolved lab conditions to total recoverable metal at ambient conditions for the following metals: cadmium, copper, lead, nickel, silver and mercury.

4. The chronic criteria for Chromium (T) are given in the total recoverable form and are not converted to a dissolved lab condition or to the total recoverable ambient condition.

5. A standard mass balance equation determines the total allowable concentration (permit limit) for each pollutant. This equation also includes a percent stream allocation of 90%.

The following equations are used to evaluate water quality protection:

Eqn: Cm = QsCs + QwCw Qs + Qw where:

Cm = resulting in-stream concentration after mixing Cw = concentration of pollutant in wastewater Cs = stream background concentration Qw = wastewater flow Qs = stream low flow to protect water quality:

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-17 of R-41 Eqn: Cw < S_) [Cm (Qs + Qw) - QsCs]

Qw where: (SA) = the percent "Stream Allocation".

Calculations for this permit have been made using a standardized worksheet titled "Water Quality Based Effluent Calculations", shown below.

Division policy dictates the following procedures in establishing these permit limits:

1. The critical low flow values are determined using USGS data:

Fish and Aquatic Life Protection 7Q10 - Low flow under natural conditions 1Q10 - Regulated low flow conditions Other than Fish and Aquatic Life Protection 30Q2 - Low flow under natural conditions

2. Fish & Aquatic Life water quality criteria for certain Metals are developed through application of hardness dependent equations. These criteria are combined with

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-18 of R-41 dissolved fraction methodologies in order to formulate the final effluent concentrations.

3. For criteria that are hardness dependent, chronic and acute concentrations are based on a Hardness of 50 mg/L and Total Suspended Solids (TSS) of 10 mg/L unless STORET or Water Supply intake data substantiate a different value.

Minimum and maximum limits on the hardness value used for all water quality calculations are 25 mg/L and 400 mg/L respectively.

4. Background concentrations are determined from the Division database, results of sampling obtained from the permittee, and/or obtained from nearby stream sampling data. If this background data is not sufficient, one-half of the chronic "In-stream Allowable" water quality criteria for fish and aquatic life is used. If the measured background concentration is greater than the chronic "in-stream Allowable" water quality criteria, then the measured background concentration is replaced with the chronic "In-stream Allowable" water quality criteria for the purpose of calculating the appropriate effluent limitation (Cw). Under these circumstances, and in the event the "stream allocation" is less than 100%, the calculated chronic effluent limitation for fish and aquatic life should be equal to the chronic "in-stream Allowable" water quality criteria. These guidelines should be strictly followed where the industrial source water is not the receiving stream.

Where the industrial source water is the receiving stream, and the measured background concentration is greater than the chronic "In-stream Allowable" water quality criteria, consideration may be given as to the degree to which the permittee should be required to meet the requirements of the water quality criteria in view of the nature and characteristics of the receiving stream.

Each worksheet has fourteen (14) data columns, all of which may not be applicable to any particular characteristic constituent of the discharge. A description of each column is as follows:

Column 1: The "Stream Background" concentrations of the effluent characteristics.

Column 2: The "Chronic" Fish and Aquatic Life Water Quality Criteria. For Cadmium, Copper, Lead, Nickel, and Zinc, this value represents the criteria for the dissolved form at laboratory conditions. The Criteria Continuous Concentration (CCC) is calculated using the equation:

Eqn: CCC = (exp { mc [In (stream hardness) ] + bc 1) (CCF) where: CCF = Chronic Conversion Factor This equation and the appropriate coefficients for each metal are from Tennessee Rule 1200-4-3-.03 and the EPA guidance contained in The Metals Translator: Guidance For CalculatingA Total Recoverable Permit Limit From a Dissolved Criterion (EPA 823-B-96-007, June 1996). Values for other metals are in the total form and are not hardness dependent; no chronic criteria exist for silver. Published criteria are used for non-metal parameters.

Column 3: The "Acute" Fish and Aquatic Life Water Quality Criteria. For Cadmium, Copper, Lead, Nickel, Silver, and Zinc, this value represents the criteria for the dissolved form at laboratory conditions. The Criteria Maximum Concentration (CMC) is calculated using the equation:

Eqn: CMC = (exp { mA [In (stream hardness) ] + bA} ) (ACF) where: ACF = Acute Conversion Factor

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-19 of R-41 This equation and the appropriate coefficients for each metal are from Tennessee Rule 1200-4-3-.03 and the EPA guidance contained in The Metals Translator: Guidance For CalculatingA Total Recoverable Permit Limit From a Dissolved Criterion (EPA 823-B-96-007, June 1996). Values for other metals are in the total form and are not hardness dependent; no acute criteria exist for Total Chromium. Published criteria are used for non-metal parameters.

Column 4: The 'Translator' converts the value for dissolved metal at laboratory conditions (columns 2 & 3) to total recoverable metal at in-stream ambient conditions (columns 5 &

6). This factor is calculated using the linear partition coefficients found in The Metals Translator: Guidance for Calculating a Total Recoverable Permit Limit from a Dissolved Criterion(EPA 823-B-96-007, June 1996) and the equation:

Cdiss 1 Eqn:

Ctota 1 + { [Kpo] [ss(I+a)] [106] }

where: ss = in-stream suspended solids concentration [mg/I]

Linear partition coefficients for streams are used for unregulated (7Q10) receiving waters, and linear partition coefficients for lakes are used for regulated (1Q10) receiving waters. For those parameters not in the dissolved form in columns 2 & 3 (and all non-metal parameters), a Translator of 1 is used.

Column 5: The "Chronic" Fish and Aquatic Life Water Quality Criteria at in-stream ambient conditions. This criteria is calculated by dividing the value in column 2 by the value in column 4.

Column 6: The "Acute" Fish and Aquatic Life Water Quality Criteria at in-stream ambient conditions. This criteria is calculated by dividing the value in column 3 by the value in column 4.

Column 7: The "Chronic" Calculated Effluent Concentration for the protection of fish and aquatic life. This is the Chronic limit.

Column 8: The "Acute" Calculated Effluent Concentration for the protection of fish and aquatic life. This is the Acute limit.

Column 9: The In-Stream Water Quality Criteria for the protection of Human Health associated with the stream use classification of Organism Consumption (Recreation).

Column 10: The In-Stream Water Quality Criteria for the protection of Human Health associated with the stream use classification of Water and Organism Consumption.

These criteria are only to be applied when the stream use classification for the receiving stream includes both "Recreation" and "Domestic Water Supply."

Column 11: The In-Stream Water Quality Criteria for the protection of Human Health associated with the stream use classification of Domestic Water Supply.

Column 12: The Calculated Effluent Concentration associated with Organism Consumption.

Column 13: The Calculated Effluent Concentration associated with Water and Organism Consumption.

Column 14: The Calculated Effluent Concentration associated with Domestic Water Supply.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-20 of R-41 NOTE: The calculated chronic water quality effluent concentrations from Column 7 should be compared, individually, to the values calculated in Columns 12, 13, and 14 in order to determine the most stringent chronic permit limitations. The calculated acute water quality effluent concentrations from Column 8 should then be compared, individually, to values equal to two (2) times the values presented in Columns 12, 13, and 14 in order to determine the most stringent acute permit limitations. These water quality based limits are compared to any technology based (CFR or Tennessee "Rules")

effluent limitations, and/or any previous permit limitations, for final determination of the permit limits. TVA has demonstrated that Priority Pollutants will not be discharged in cooling tower blowdown in amounts that are detectable by analytical methods in 40 CFR Part 136. Monitoring for the Priority Pollutants will not be required.

Storm Water The Tennessee Multi-Sector General Storm Water Permit (TMSP) No.TNR050015 covers storm water discharges associated with the industrial activity of this facility. Storm water concerns associated with this facility are covered in this general permit, so they will not be addressed in detail in the individual NPDES permit.

Since it is the intent of the division that the permittee institutes a Storm Water Pollution Prevention Plan (SWPPP) in order to minimize the discharge of pollutants from storm water outfalls. It is the opinion of the division that the best method for dealing with potential pollution associated with storm water discharges from the TVA-Sequoyah Nuclear Plant facility is through implementation of an aggressive SWPPP coupled with the TMSP to verify SWPPP discharge monitoring effectiveness.

In order to assist the permittee in the evaluation of the effectiveness of the SWPPP, benchmark values developed for the TMSP for Industrial Activities are provided herein for comparison. These benchmark values (cut-off concentrations) were developed by the EPA and the State of Tennessee and are based on data submitted by similar industries for the development of the multi-sector general storm water permit. The cut-off concentrations are target values and should not be construed to represent permit limits.

Parameters of Concern Cut-Off Concentration

[ag/IL]

Total Suspended Solids (TSS) 200 Oil & Grease 15 Iron, TOTAL 5.0 pH (range) 5.0- 9.0 Note: Sample values are from the Tennessee Storm Water Multi-Sector General Permit for Industrial Activities, Rationale, Part Ill, Table Ill-A: ParameterBenchmark Values.

The new permit will contain a requirement that a Storm Water Pollution Prevention Plan be developed and maintained to regulate storm water runoff. This SWPPP is meant to ensure that runoff from the facility site is not a significant source of pollution to the receiving stream. The discharger will develop, document and maintain

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-21 of R-41 the SWPPP pursuant to the requirements as set forth in the Tennessee's Storm Water Multi-Sector General Permit for Industrial Activities, Sector 0, "Storm Water Discharges Associated with Industrial Activity from Steam Electric Power Generating Facilities, Including Coal Handling Areas", Part 3, "Storm Water Pollution Prevention Plan Requirements", as included in the ATTACHMENT I of this permit also found at http://www.state.tn.us/environment/wpc/stormh2o/pmt-o.pdf. The effectiveness of this SWPPP will be examined by requiring storm water monitoring data be submitted of the combined process/storm water discharges. At that time, should the results so dictate, the division maintains the authority to institute specific numeric limitations for the monitored parameters.

IX. BIOMONITORING REQUIREMENTS, CHRONIC The discharge of industrial wastewater from Outfall 101 may contain several different pollutants, the combined effect of which has a reasonable potential to be detrimental to fish and aquatic life. The Tennessee Water Quality Standards criteria stipulate that "The waters shall not contain toxic substances, whether alone or in combination with other substances, which will produce toxic conditions...".

Where the stream is the source, calculation of toxicity limits follows:

Dilution Factor = Qs Qw where: Ow is a wastewater flow (Qw = 1509 MGD) and Os is a receiving stream low flow (1Q10, estimated at 3491 MGD). Please refer to Appendix 1 for specific details regarding facility discharge and receiving stream.

Therefore, IWC is Instream Waste Concentration and is calculated using the following formula:

Qw IWC - X 100 = Instream Waste Concentration as IWC - Qw x 100 - Instream Waste Concentration Qs Where: IWC < 1.0 X IC25; or, INHIBITION CONCENTRATION, 25%_> IWC

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-22 of R-41 Stream Is Source Stream Wastewater Total Flow Flow Flow

[MGD] [MGD] [MGD]

3491 1509 IF 3491 DF 2.3 LC50 > 144.1 IC25> 43.2 Specifically:

WET testing will now be required on 43.2% effluent based on new flow data provided with this permit renewal application. Toxicity demonstrated in any of the effluent samples as specified above will serve as a trigger for accelerated monitoring.

The toxicity tests specified herein for Outfall 101 shall be conducted according to the B/CTP and begin during the first chemical application requiring biomonitoring following the effective date of this permit. WET frequency and results reporting will be governed by the B/CTP. However, in order to effectively track WET monitoring, monthly reporting shall continue. For monitoring periods when WET testing is not required by the approved B/CTP, monitoring not required, or "MNR" shall be reported on the discharge monitoring report (DMR) or electronic report (if being used) to reflect that monitoring is not required.

X. OTHER REQUIREMENTS A. BEST MANAGEMENT PRACTICES Best management practices are included in the permit. Best management practices will apply to the activity that is likely to cause or contribute to pollution of the state's waters. The best management practices under this permit may be combined into a single document with the storm water pollution prevention plan (SWPPP) required under the TMSP general permit TNR050015 if the permittee wishes.

Liquid radwaste is treated by a Liquid Radwaste System and discharged into the cooling channel. The water discharged is mixed with the cooling water and discharged through Outfall 101. Liquid radwaste treatment is to collect and treat those liquids, which are radioactive or potentially radioactive. The treatment typically includes activated carbon, cation exchange resins and a mixed bed resin. Chemical pollutant concerns are minimal, for this waste. Past data and process knowledge indicate that the effluent requirements for low volume wastes are met for this system. The liquid radwastes will be handled according to the TVA-SQN best management practices (BMP) plan.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-23 of R-41 Best management practices will be included for toxics and hazardous materials control as well as pollutants defined under the Tennessee Water Quality Control Act.

The BMP plan shall also include:

1. Biocide treatments for in-plant systems and an approved mechanism for notification and Division approval that should not delay changes needed to protect both the systems of the facility and all manner of plant and aquatic life in waters of the State. This shall be accomplished by amending the B/CTP, but will not require permit modification.

2. Construction and repairs with potential for pollution contributions that are not routed to an appropriate treatment system.

3. Housekeeping and maintenance standard practices manuals.

4. Minimization of pollutants that could result from the backwash activities at Outfall 116 and Outfall 117.

B. CWA Section 316 APPLICATIONS and STUDIES Section 316(a) allows temperature variance where balanced populations are being protected. Section 316(b) Rule (September 7, 2004) requires that intake designs be implemented to minimize adverse impacts on the aquatic life. Both of these aspects are addressed in the permit including an evaluation of the mixing zone used in the permit.

C. DISCHARGE MODEL CALIBRATION Diffuser discharges are modeled and the model results used to determine compliance. The characteristics of the model and discharge situation may vary with time. Therefore, calibration of the diffuser flows and the model will continue to be conducted as in the previous permit.

XI. XIII. ANTIDEGRADATION Tennessee's Antidegradation Statement is found in the Rules of the Tennessee Department of Environment and Conservation, Chapter 1200-4-3-.06. This statement outlines the criteria for the two types of high quality waters. Outstanding National Resource Waters (ONRWs) are designated by the Water Quality Control Board. Other high quality waters, as identified by the division, are referred to as Exceptional Tennessee Waters. Other surface waters not specifically identified and/or designated as high quality are referred to as Available Conditions Waters. Some available conditions waters may be identified by the division as either not meeting water quality criteria or needing additional water-quality based controls to prevent excursion of criteria for some parameters and conditions and are referred to as Unavailable Conditions Waters for those parameters or conditions.

The division has made a stream tier determination of the receiving waters associated with the subject discharge(s) and has found the receiving stream to be other than a high quality water. Additionally, this water is fully supporting of its designated uses. The Department has maintained, and shall continue to assess, the water quality of the stream to assure that the water quality is adequate to protect the existing uses of the stream fully, and to assure that there shall be achieved the highest statutory and

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-24 of R-41 regulatory requirements for all new and existing point sources and all cost-effective and reasonable best management practices for nonpoint source control.

XII. PERMIT DURATION The proposed limitations meet the requirements of Section 301(b) (2) (A), (C),

(D), (E), and (F) of the Clean Water Act as amended. It is the intent of the Division to organize the future issuance and expiration of this particular permit such that other permits located in the same watershed and group within the State of Tennessee will be set for issuance and expiration at the same time. In order to meet the target reissuance date for the Tennessee River (Hamilton Co. Except Chattanooga) watershed and following the directives for the Watershed Management Program initiated in January 1996, the permit will be issued to expire in the year 2013.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-25 of R-41 APPENDIX 1 I

OUTFALL 101 RECEIVING STREAM LONGITUDE LATITUDE DISCHARGE ROUTE 85-05-14 35-12-35 Tennessee River at mile 483.65 FLOW DISCHARGE STREAM LOW 7010 1010 3002 (MGD) SOURCE FLOW (CFS) 6250.00 5400.000 8490.00 1447.0000 Condenser Circulating Water ('Open" mode) (MGD) 400 5468.8 40.4100 Essential Raw Cooling Water (ERCW) 2.1250 Yard Drainage Pond (9.5 MilGal) STREAM USE CLASSIFICATIONS (WATER QUALITY)

(incL bldg. sumps, nisc. air conditioner cooling water ISH FEMH11 T RFMPAT' I LW&W DMWW auxiliary bldg. cooling water, misc. waters, and x x X stormwater runofffirom 186.4 acres of property) roLSTwtA __________

1.1900 Low Volume Waste Treatment Pond x _

(10 MIlGal. Pond: Outfall 103) 1490.7250 TOTAL DISCHARGE*

Outfall 101 identifies discharge from the Diffuser Pond to the Tennessee River and is the primary discharge of the facility.

Note that the total discharge value may differ slightly from the schematic protided with the application, and the number used for other calculations.

The Diffuser Pond receives discharges from IMP 103 and IMP 107.

1 FAI0TY =SHARK1EAW IECE3NGWAMF8 I OL1FIL1 FEEYINSTREAMt RLJ3W DISCHARG SrREAM LD 17010 1 1010 [ 3002 1516.25 Gnimerioatinguater (UNAj (1000O 0.000 7 40.32 rtsmtalrwcoiugsa% _____________

37.179 Rawccolingwaky F 5flAMULECLASIFCATIOS(M1A~TEOMUTY 0.75D Ramgne~ratorUaobo FISHl~ IfmnC AW LvBT EOMERC L aiq~eftMa regenebo mtes frcsm L xL.... X X

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_______ ___

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15K5ft4 arAL DISCHARG frschsW eatWWIf110 wolld coir if part operates in"doseerl rrade, djirig Which time sluvem voter eystes YD~dddschare%4a jQffail 110 to the Odats intlefr ebely. Indosed rrdB operzfinr Yaer redraialles back to the itdle fMebey and isPUiIed bB~k int the piant irtaim aased mxod mrabon isriot Used mdte rrrw mm-d pitea faticrs

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-26 of R-41 APPENDIX 1 (continued)

I FAaIUTY 101SCHAMIS NDFEEVtNGWAj5R I InWM Witairig Ptirt CUMALL103 UNMUCE LAMUEE STbFftM LOW 1O 7010 1) ICAO-~e 1 3 FLOW MCKAME (MGq SCUME _ _m - _ 1 QO 0 1 L 1.1371 CwdmsAeDadner@1izer(OonO) dminediaw, Ubirwý bLildnq sirp eMaormawmnaff SMLEAF USE R CATK IE2 8iAT HSH- RFA1Tm iImG1UJ ____ L tmvSTCC MrALMMOME Treabnen: Valies franm mreto rmubalzaimFnal tieabTent ispimidd bysecdnwtam and cil s~rmrir ina 10 rniIlicn gIai pond Fefererme FlovwDim and LoN Ros di Tariesse Stambuti 199 by CGecr S CudandJess D.Wma~e.

Wae Resoares Irwasicns Fapot 95A293 pqwaed tythq US Gedocacl &m~y inQqpperahn with the Taervssee Depatrhertdci riasner, and Qrisevafic and1 theTerressee Vaily Admttiy, Naslle, Tennessee, 199a I RDU 7Y c 0IM P EC MNG WAT EM Irtwel Mnitaing Pdrft CUMALL10-1 UNMUDE LAMUCEE Wata- s pp frsixrm d~rc~gYwd a , Wid MABTnD~rrxt 1r(OAM~ 101) Wc ains irMtooDvfki r

~A O13- 1 1~ 1~Gfl~ IL M

___ ____11_

x x x __ __ _

IM'DEMA- NVIAV1TMN __ _ _ __ _ _ _

cwcjI ~ TMALDBOIWfl x____

Trearst Sedlnejticr, nebza ibcn,aeiaUa ard ienicai precpfitam rinme-nicn galcn pond series Pdererm FlcwiEfztin and Low Romsd Tenne~ssee Sbeanshtrxi~19M by George S QljamiJess D.

WeaverM. Water Remroes Inmsigtm Rbepo~rt 954Z)3 prepared bythe US (Gedocacl&RrmyinQroperavcsl Wth the Tennessee Deparbtru d ciarin and Qiwvrtai and lie Tennessee Valley Affadiy, Na~~tdle, Tennessee, 1M6.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-27 of R-41 APPENDIX 1 (continued)

I FACILITY DISCHARGES AND RECEIVING WATERS I RECEIVING STREAM LNGITUDE LATITUDE DISCHARGE ROUTE OUTFALL35-13-33 F 85-105-13 116 Discharges to an embayment of Chickamauga Reservoir at Tennessee River mile 485.3.

FLOW DISCHARGE (MaD) SOURCE I STREAM LOW I 7010 I 1010 1 3002 0.060 Washwater from the FLOW (CFS)

I I Condenser Circulating Water Trash Sluice (MOD) 1I o o1I1 o-o 11 o, STREAM USE CLASSIFICATIONS (WATER 0UALIT SH IRECREATION IRRtGA1n I LW&W IDOMES11C x_ _ _ __ _ _ ___I___

0.0600 TOTAL DISCHARGE This is an intermittent discharge from the backwash of debris from screen and strainers of the Condenser Cooling Water system to an embayment of the Tennessee River north of the power plant.

I FACILITY DISCHARGES AND RECEIVING WATERS I I OUTFALL117 RECEVNG STREAM LONGITUDE LATITUDE DISCHARGE ROUTE 85-05-03 35-13-32 Discharges to Tennessee Fiver at mile 484.9.

FLOW DISCHARGE (MGD) SOURCE STREAM LOW 17010 1010 3002 0.0140 Backwsh ofthe Essoental Raw Water FLOW (CFS) * = -

Intakse Scmenand Stnncr (MMD) IL 0 0.0 1 0.0 STREAM USE CLASSIRCATIONS (WATER 0UAiJ FISH RECREATON II:GAT1ON LW&W DOMES'IC INMUTR=AL NMAVGA.'ON x x I 0.0140 TOTAL DISCHARGE This is an intermittent discharge from the backwash of debris from screen and strainers of the Essential Raw Cooling Water system to the Tennessee River.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-28 of R-41 APPENDIX 1 (continued)

FACILITY DISCHARGES AND RECEIVING WATERS I RECEIVING STREAM LONGITUDE [LATITUDE DISCHARGE ROUTE 85-05-03 OUTFALL 35-13-32 118 Discharges to intake forebay FLOW DISCHARGE (MGD) SOURCE STREAM LOW j 7010 1 110 I 3002F n/a Storm water runoff only, from the inactive FLOW (CFS)

I I ERCW dredge pond; no industrial activity present. (Mo) -0.0 0 0.0 0.

STREAM USE CLASSIFICATIONS (WATER GUALITY)

FIqiH RECREATION IRRIGATION LW&W DOMESTIC X X X X X INDusTRIAL NAVIGATION 0.0000 TOTAL DISCHARGE Discharge from the Essential Raw Cooling Water dredge pond is inactive, except for storm water runoff from the vegetated area.

This pond could be used for temporary disposal of sediment dredged from intake channel providing water to the plant. Such dredging would be conducted when there is need to restore the channel depth to acceptable level.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-29 of R-41 APPENDIX 2 APPLICABLE EFFLUENT LIMITATIONS GUIDELINES 40 CFR PART 423 EFFLUENT LIMITATION GUIDELINES STEAM ELECTRIC POWER GENERATING POINT SOURCE CATEGORY Low Volume Waste Sources 6423.112(b)(0) - BPT §423.13 - BAT Average of Daily Maximum Average of Daily Maximum Values for 30 for Values for 30 for EFFLUENT Consecutive Days Any 1 Day Consecutive Days Any 1 Day 41 ... p CHARACTERISTIC Ima/l Ima/li lma/il lmg/Ij TSS 30.0 100.0 ....

Oil & Grease 15.0 20.0 pH 6.0-9.0 6.0-9.0 Note: 1. The quantity of pollutants discharged shall not exceed the quantity determined by multiplying the flow of low volume waste sources times the concentration listed. At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of the mass based limitations specified. Concentration limitations shall be those specified above.

2. There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-30 of R-41 APPENDIX 2 APPLICABLE EFFLUENT LIMITATIONS GUIDELINES (continued) 40 CFR PART 423 EFFLUENT LIMITATION GUIDELINES STEAM ELECTRIC POWER GENERATING POINT SOURCE CATEGORY Metal Cleaning Wastes

§423.12(b)(5) - BPT §423.13(e)- BAT Average of Daily Maximum Average of Daily Maxdmum Values for 30 for Values for 30 for EFFLUENT Consecutive Days Any 1 Day Consecutive Days Any 1 Dav f CHARACTERISTIC Ima/ lI Im/Wll Imail TSS 30.0 100.0 ....

Oil & Grease 15.0 20.0 -- -

Copper () 1.0 1.0 1.0 1.0 Iron ()6 1.0 1.0 1.0 1.0 pH 6.0-9.0 6.0-9.0 -- --

Applicable to chemical metal cleaning wastes.

Note: 1. The quantity of pollutants discharged shall not exceed the quantity determined by multiplying the flow of metal cleaning wastes times the concentration listed. At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of the mass based limitations specified. Concentration limitations shall be those specified above.

2. There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid.

3. §423.12 refers to metal cleaning wastes while §423.13 refers to chemical metal cleaning wastes only.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-31 of R-41 APPENDIX 2 APPLICABLE EFFLUENT LIMITATIONS GUIDELINES (continued) 40 CFR PART 423 EFFLUENT LIMITATION GUIDELINES STEAM ELECTRIC POWER GENERATING POINT SOURCE CATEGORY Once Through Cooling Water

§423.12(b)(6- BPT §423.13(b) - BAT Average Maximum Average Maximum EFFLUENT Concentration Concentration Concentration Concentration CHARACTERISTIC [ma/Il I [ma/l1 [ma/lI I [ma/1 Free Available Chlorine 0.2 0[.5 0.2 "01.

Total Residual Chlorine .... 0.20*

§423.12 is applicable to all plants. §423.13 is applicable to plants with a total rated electric generating capacity of less than 25 megawatts only. Neither free available chlorine nor total residual chlorine may be discharged from any single generating unit for more than two hours in any one day and not more than one unit in any plant may discharge free available or total residual chlorine at any one time unless the utility can demonstrate to the permitting authority that the units In a particular location cannot operate at or below this level of chlorination.

Plant with a total rated electric generating capacity of 25 or more megawatts only. Total residual chlorine may not be discharged from any single generating unit for more than two hours per day unless the discharger demonstrates to the permitting authority that discharge for more than two hours is required for macroinvertebrate control. Simultaneous multi-unit chlorination is permitted.

Note: 1. The quantity of pollutants discharged shall not exceed the quantity determined by multiplying the flow of once through cooling water times the concentration listed. At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of the mass based limitations specified. Concentration limitations shall be those specified above.

2. There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-32 of R-41 APPENDIX 3 PREVIOUS PERMIT LIMITS OUrFALL 101 Qrkfw~ciirg~te, Bsenfid PaN00dirnV~bt, Coodlg Tome BcmcbaI ftw~oxrigWa, LowVcdkrmv&" kw Oeairg Vvf S itary~ae~Adi, Msoelams LowVdum wager it-duinariou Fadifies D~ins " aIps ACQonclsaite Stemn~eina~r BcamdwI FkP~ PRsain Rre Rdedhnia~eder, Fkpiezta, V~e FtromCn se Dermn~~edw, a"iSbtVarmAW&Rn I'

S10 UlWI[AI1lJ0re WLI" KJ1om MOLr-DV 1nAILY E..LLEIT AV N~ X OOC MACIAG I MAX AWiff NfWMJ' SMRLE CHARACTBEIS1C ( LIO I O~a) nl) I OŽdL.. _FR1CY. Tym AMBEWTEW. ___________ AtQim CA1,1 RVERTEP. 3O5DgCCalfiuou ~dd 04MINEOI.Fille) 0.0 0.05W 1Mjjff _____Ca~k Pes NIUSIS-OPCE ND0OISO-IAROE ______Gra pH rm 0Pnsa 9. lIAAeek Grab_

CILAINDGFASE 15 201AV~e ______

7w__ 30 10 AAkek Ga

___ C25____ SjiV~4 FPuvodctricn, & GuaAin 4a9%B Eflatý 1IQate I_______

Swetma jate~dffthte nmribtrecJe, im spedfledbastllbt afdb~ Row- saa~ac eptwiteoftlertytothe

'Mmwwut shel lnbe n ey 15 nrr'Jte at th 1-nal, I Sxnata, ar 24rder dos anhedlatbma v tothpla~it. Twpw'h athatTm depths shal beaceIedey 15nrdmietog veater~eraumalf 1.5-ineerd Both 1-trxarad244tmranaes dl heda11fned 15flirtLsfG IheAriertTepai~carud1RverTerpa~La(i.e., Idngramag). The 1-hmwvage~stdi becapjtedb/&mngtheoamet %ekenadtheITeviut fai 15iiirUevdum lie a44uoa~psgdbem~d ya 15-nlinTr uesovu24hni 2 Setetdu dwtaieka'txtffirfa~ramlc

' See pert IIIkfaWvdsa~cdtaddtytests.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-33 of R-41 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS FERfUUMs QJTFAIL10Y3 Dde~dir~i Fegawicn frcm Rat 2Dainralize, Tulime BidrigSjz Tredsdvd Ce~nigV~efttma~fl 107axISlam Vxks'Rniff t1iMLLII UM UUIUl% PAL" M"M NIOITI'LY DIiLY FECUFENENIS EfflW ANGON I AMiF. MAXM I AMN 1%NEKN SAMPLE RON pbo~vGm Rqot(rvtt Iboade Tcdze I"1 FbW.-90RWO-RO 3Vb* emb CILAVGEW 15I~ 1910M5 vt Gab 7W___D__D 100 125 1Ab O Ntele emttt~d~dTu~bineiing& pisdsdilpIymtofrQ(W~ludrd yiddainr ci, (continued)

PERIVUUIIITS OUTFALL 107 Metal Cleaning Wastew~ater and Stom Water uinoff EFFLUEN~T UI'TA11ON~S NMOI.ITFqNG

_____________ O;n.LY DAILY FEWIJJ1 EFFLLENT Av- AGAW x m~~r msRmN. &AmPLE CHAPACT5MSTC (no Mc)I oic) mNY TYPE R.CWV Reortr (tvD) Reot(MG) 1/Day CIalciation pHRne60-9.0 Rarng .0-9.0 I/Day Grab COLANDGRASE - -15 I /Day Grab TSS - -30 I-/Day Conse COPPER () - 1.0 1-.a ý Conwote IRN - 1.0 I-/Day Co~aite PHOSPHOROUS (P) o 1.0 1/Day Con~osite Nital cleaning waste shall me any cleaning conpounds, rinse waters or any other wattaixwrsiridues derived fiom cleaning any rmetal pocess eqiprient Meal clea waste shall nit be discharged into a pnd(s) before all non-metal cleaning liquids have been mnoved to the extent practical without discharging previously removed solids.

In the evert that netal cleaning wastes mint be picmsed and discharged through the liquid radwaste system, the limitations and monitoring requitients above shall apply to the discharge fiom the liquid radwaste system prior to *mxing with the Cooling Tower Blowdown.

Ther shall be no distinct discharge of floating scumi, solids, oil sheen visible foam. and oter floating flatter inother than Uwe anmouts.

Saiples taken in omnpliance with the mnitoring require'nnts specified above shall be taken at the following locationrs):

Discharge from the individual pond(s) prior to mixing with any other waste stream 1 Limitations aid monitorinm rmuiren-nts shall molv only if6dxanl us bearing cleanins solutions are used.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-34 of R-41 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS (continued)

PEMTUMTS OWrF.LL 110 Comm CodinggWater, Essaeta FawCoolingVWa', FPwwodingWa~tr, Ms R.BIETUMIWTA1IONS IVlNTORNG MONiHLY DAILY Ri JIEWJVIBGS E5R.LBJ AN COC WAWýMA OCIMXAN NERM'JL SAMPWLE CHAAC4R~SM (nl I yac) (AIOU& RNY TYPE RDWI Fapxit(N ) ___ ___ (NJ ___ I/Dy aiatiao pHR39 .- 9.0 BL Fbxj 6.0 -9.0 I/Day _Gra aLANDCFASE -- 15 - ____Grab iss - 30_ -/a -m- - ite caP(T)- - 1.0 -/a ovst HI0FIKRJQM - 1.0 -1/Eay Cunposte Nt]deri mteg hal mean my deain cu11m*x firwierst oranyofe %matame resdue dnwdfiandeaning any nietl mme4pft NtW~ cleaing vse shll not b iscm~d inmto a pons) befie aUl nomtan cleaing liquids havebeen ranomc to tiv Inthe event doa nW cleanig "ate ist be pmedsed and didxa R1dm*te liqud radse syste;thefrihitatici and mnitrng re~ ritfs abo'.vshall appy to &hdisdH&fiun the liudxrare sý pdr to mmng W4ith te GooingTmer Bkmdown.

Sanpstakenin oxrplianoe wth thde rnonitaing re4&uients spefiedabov~eshall be talari at die fllowing location~s):

DtdWfu h nii o~)pirt on ihayohrwsesra IUnitaticns andntinitonng iegaruariets shall appy ony ifphostmwbemung elmning solutions am used

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-35 of R-41 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS (continued)

PERITI.IWS 0UrFA.S 116 ar1117 11fk a~Wuftrcmftt WWfI rae c~adrwoi Tkmdsdnpaep 4ediutdm1c1 nuionngm smt PERffUNTM1 O.JIF.L 118 I ERIBrUMTAIIUB FJINTURN3 MCNFlLY DAILY F~JRBtMB8 EJBRL AXII ýK1 ANG AMiEmx jgj7 o- A m ~mmE sAm~E CFAPnRt (WO- lu W(a !LLJ (09txt) 1. F. p v "

__ _ _ _ Fapat NGm 1I3tc Esnre S~rzrnirnC ZJIZIIJDGz Tll~bedmdt hritaflcatMdnniW umdyw~vyatmfosadixdfloar5omdfdtmrgti&~

SftdumimInt nfitpamicsgeUpitoUtdfitdamdsflbwcpni

=% f iesidixaho~ftpmsil

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-36 of R-41 APPENDIX 4 HISTORICAL MONITORING AND INSPECTION Outfall 101 PARAMETER FLOW TSS TRC BORON PH TEMP DIFF TEMP RATE RIVER TEMP Units MGD mg/I mg/I mg/I SU deg C deg C deg C Maximum 1787 38 0.056 1.5 8.52 4.8 2 31.3 Minimum 498 1 0 0.2 6.85 -1.1 -2.1 4.9 Average 1509.64 5.42 0.01 0.22 1.61 0.09 19.87 Median 1578 5 0.011 0.2 7.57 1.6 0.1 20.4 Count 3897 674 4133 106 914 3893 3893 3893 Outfall 103 PARAMETER FLOW TSS OIL& GREASE PH Units MGD mngl mg/I SU Maximum 3.621 43 11 9.29 Minimum 0 1 5 623 Average 1.14 9.87 5.25 Median 1.146 9 5 7.75 Count 3895 709 722 1809 Outfall 107 PARAMETER FLOW TSS OIL & GREASE PH COPPER IRON Units MGD mg/I mg/I SU mg/I mg/I Maximum 0.082 19 6.2 8.99 0.023 1.8 Minimum 0.012 1 5 7.26 0.001 0.03 Average 0.03 3.55 5.03 0.00 0.31 Median 0.032 3 5 8.35 0.002 0.19 Count 163 163 164 165 164 169

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-37 of R-41 APPENDIX 5a NEW PERMIT LIMITS AND MONITORING REQUIREMENTS WATER QUALITY BASED EFFLUENT CALCULATIONS FACILITY: Sequoyah Neclear Plant PERMIT #: TN0026450 Stream Stream Waste d tI Susp. Hardness Stream (1010) (3005) Flow Solids (as CaOO3) Allocation IMGD] [MGD] [MGDI [mgJl] [mg/I] [%]

3483.0 7740.0 1509.6 10 56 90 1 2 1 3 4 5 1 6 7 1 a Stream FistVAqua. Ufe Effluent Fash & Aquatic Life Water Oust Critera (1020)

Bckgmd. Water Quality Crtteda Fraction In-Stream Allowable CCe.cEffluent Concentration EFFLUENT Conc. Chronic Acute Dissolved Chronic Acute Chronic Acute CHARACTERISTIC lug/I] [ug/] [ugA] [Fraction] [ugA] [ug/i] [ug] [ug/1]

Chlorine (T. Res. 0.000 11[00 19.000 100 11.000 19.000d 36. 62.8

[9 1 0 11 1 12 1 13 1 14 L Human Heasth Water Criteria (3002)

Iuaity In-Stream Critena CaIc. Effiuent Concentration EFFLUENT Organisms ýater/Organisanm DWS Organisms Vater/Organisml DWS CHARACTERISTIC [ug/] lug/Il [ugAi] [ug/I] I ug] Nug/i]

[Chlorne ('. Res.) NA NA NA NA NA NA NOTE: Water Quality criteria for stream use classifications other than Fish & Aquatic Life are based on the 3005 flow.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-38 of R-41 APPENDIX 5b New Permit LIMITS PERMIT LIMITS OUTFALL 101 Condenser Circulating Water, Essential Raw Cooling Water, Cooling Tower Blowdown, Raw Cooling Water, Low Volume Wastes, Miscellaneous Low Volume Wastes, including Various Facilities Drains and Sumps, A/C Condensate, Steam Generator Blowdown, High Pressure Fire Protection water, Regeneration Wastes From Condensate Demineralizer, and Storm Water Runoff EFFLUENT LIMITATIONS MONITORING MONTHLY DAILY REQUIREMENTS EFFLUENT AVG.NCON[I AVG. AMNT. MAX.CONC. MAX.AMNT. MSRMNT. SAMPLE CHARACTERISTIC mr/[IL lIb/day) (rag/l (lb/day) FRONCY. TYPE 2

FLOW Report (MGD) Report (MGD) Continuous Recorder ,

AMBIENT TEMP. -- Report (Deg.C) Continuous Calculate 5,2 RIVER TEMP. Report (Deg.C) Continuous Calculate 1,5 CHLORINE (TtI.Res.) 0.04 0.06-- 5/week Calculate 4,s See Permit and IC25 Survival, Reproduction, & Growth In 43.2% Effluent Note' Composite 3 1 Samples taken in compliance with the monitorng requirements specified above shall betaken as follows: Flow-sampled at diffusergate priorto entry to the Tennessee River, Ambient Temperature - river side of the plant intake skimmer wall; River Temperature -river temperature, temperature rise, and rate of temperature change shall be determined by numerical model.

2 See text below table forfurther Information that applies to this outfall (101). WET testing frequency and results reporting will be governed by the B/c'P. However, In order to effectively trackWET monitoring monthly reporting shall continue. For monitoring periods when WET testing is not required by the approved B/CTP; monitoring not required, or"MNR" shall be reported on the discharge monitoring report (DMR) or the electronic "report (if being used) to reflect that monitoring is not required.

3 See part IlIIforfurther description of toxicity tests.

T.RC ana!yses shall be performed withln fifteen (15) minutes of sample collection.

5 The acceptable methods for analysis of TRC are any methods specified in Title 40 CFR, Part 136, as amended. The method detection level (MDL) for TRC shall not exceed 0.08 mg/A, unless the permittee demonstrates that its MDL is higher. The permittee shall retain the documentation that justifies the higher MDL and have it available for review upon request. Under the renewed permit limits, reporting of TRC at less than 0.08 mg/I shall be interpreted to constitute compliance with the permit.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-39 of R-41 New Permit Limits (continued)

PERMIT LIMITS OUTFALL 103 This is an Internal Monitoring Point (IMP).

Condensate Demineralizer (CON DI), Turbine Building Sump, Essential Raw Cooling Water, Raw Cooling Water, and Storm Water Runoff EFFLUENT LIMITATIONS MONITORING MONTHLY DAILY REQUIREMENTS AVG. AVG. AVG. AVG.

EFFLUENT CONC. AMNT. CONC. AMNT. MSRMNT. SAMPLE CHARACTERISTIC [mg/l) I (Iblday) (rag/L) (Iblday) FRONCY. TYPE FLOW Report (MGD) Report (MGD) Recorder Totalizer pH Report 6.0 - 9.0 Report 6.0 - 9.0 3 / Week Grab Oil &Grease 15 20 2 / Month Grab TSS 30 100 2 / Month Grab Samples taken in compliance with the monitoring requirements specified above shall be taken at the following location(s):

Low Volume Treatment Pond Discharge prior to mixing with other waste streams.

Note: In the event the Turbine Building Sump is discharged directly to the CCW Channel or the Yard Drainage Pond, TSS, Oil & Grease, and pH shall be monitored 5 / Week.

Internal Monitoring Point 107 TVA Sequoyah Nuclear Plant is authorized to discharge rain water from the defunct metal cleaning ponds (IMP107) into the Low Volume Waste Treatment Pond, (IMP103) which discharges into the Diffuser Pond (Outfallil). TVA will be allowed to direct rainwater that falls in the now defunct metal cleaning ponds to the Low Volume Waste Treatment Pond without any requirements to monitor the discharge at the defunct metal cleaning ponds (IMP107). TVA will put in place a procedure to ensure that no wastewater will be discharge to the metal cleaning ponds

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-40 of R-41 New Permit Limits (continued)

PERMIT LIMITS OUTFALL 110' Condenser Circulating Water, Essential Raw Cooling Water, Cooling Tower Blowndown, Raw Cooling Water, I EFFLUENT LIMITATIONS MONITORING I MONTHLY DAILY REQUIREMENTS EFFLUENT CHARACTERISTIC 1 CONC (QJld)

.

4 AVG.A UN. AVG. CONC.

(MOIL)

AVG.

IQld AM .

,)

MSRMNT.

FRONCY.

SAMPLE TYPE Multi Grabs TEMPERATURE 38.3"C l/Day 2 Multi Grabs CHLORINE (TtU.Res.) 0.10 1/7 Days 2 LUmitations and monitoring requirements are applicable only during periods of closed-mode operation.

There shall be no distinct discharge of floating scum, solids, oil sheen, visible foam, and/or other floating matter in other than trace amounts.

Samples taken In compliance with the monitoring requirements specified above shall be taken at the following location(s): recycled cooling water flow prior to entering the Intake Forebay.

Monitoring frequency shall be increased to i/Day multiple grab any time the discharge Is occurring and fish distress or fatality is observed in the Intake Forebay.

2 Multiply Grabs shall consist of four grab samples collected during one shift each day.

PERMIT LIMITS OUTFALL 116 and 117 Outfall 116: Backwash from the Intake of the Condenser Circulating Water Outfall 117: Backwash from the Intake of the Essential Raw Cooling Water (ERCW) System There are no effluent limits or monitoring requirements for these discharges.

The discharge shall not have a visible oil sheen and the permittee shall take reasonable steps to prevent the return of materials collected on the screens to the receiving waters in a way that causes an unattractive condition on the receiving waters.

TVA - Sequoyah Nuclear Plant (Rationale)

NPDES# TN0026450 Page R-41 of R-41 New Permit Limits (continued)

PERMIT LIMITS OUTFALL 118 Settling Pond for Dredged Material form Intake Forebay and ERCW Pump Pits (Wells)

(Only applicable when the pond is in service.)

I EFFLUENT LIMITATIONS MONITORING I. Y I MONTHLY DALLY REQUIREMENTS coNC. AVG. AVG.CONC. AVG.ANT. MSRMNT. SAMPL, EFFLUENT AVG- AMT.

CHARACTERISTIC (M1 l m.

McI fft) FROWCY.

FLOW Report (MGD)* Report (MGD)* 1/Batch Estimate SETTLEABLE SOLIDS 1.0 ml/L 1/30 Days Grab 1 TOTAL SUSPENDED SOLIDS 100 2/7 Days Grab 2.0 DISSOLVED OXYGEN Minimum 2/7 Days Grab 1 There shall be no discharge of floating scum, solids, oil sheen, visible foam, and other floating matter in other than trace amounts.

Samples taken in compliance with the monitoring requirements specified above shall be taken of a discharge from the settling pond prior to mixing with the Intake Forebay.

Grab samples shall be taken at these frequencies, Including a grab sample taken immediately prior to termination of the batch discharge.

These effluent limitations and monitoring requirements only apply at times when this settling pond Is In use as a settling basin for dredged sediment. Best Management Practices (BMP) shall be used to control runoff from the pond. Examples Include vegetative cover, silt fences, and/or hay bales.

ML110660596

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Dear Mr. Cleary:

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ML110660596

Text

Subject:

Enclosure:

Subject:

Dear Mr. Cleary:

Response

Response

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