ML24032A466

Response to Comments on Draft Vpdes Permit No. VA0052451

ML24032A466
Person / Time
Site:	North Anna
Issue date:	01/16/2024
From:	Effinger T Dominion Energy Services
To:	Mackert S Document Control Desk, State of VA, Dept of Environmental Quality
References
Download: ML24032A466 (1)

Text

BY ELECTRONIC MAIL Ms. Susan Mackert Department of Environmental Quality Northern Regional Office 13901 Crown Court, Woodbridge, VA 22193 Susan.Mackert@deq.virginia.gov RE:

Dominion Energy-North Anna Power Station Comments on Draft VPDES Permit No. VA0052451

Dear Ms. Mackert,

Enclosed are Dominions responses to the revisions to the draft VPDES permit that was received on January 4, 2024. Also, we are including revised Form 2C and Attachment G (supplemental Information) to update the description of the operations contributing flows to outfalls 021, 103, 105 and 107, and the industrial activities in outfall 014s drainage area.

Should you have any questions or require additional information, please contact Oula Shehab-Dandan at (804) 310-4881 or oula.k.shehab-dandan@dominionenergy.com.

Sincerely, Thomas Effinger Date Director, Environmental Services Enclosure Jan 16, 2024

Permit Part I.A.25 and Part III Outfall 014 receives stormwater drainage from stormwater drains located inside the northwestern part of the stations protected area, including stormwater drainage from around the SBO emergency diesel generator building. We request that it be added back in the permit and Fact Sheet.

Staff Response:

Attachment G (Supplemental Information) of Dominions application states Outfall 014 has no industrial activities associated with this drainage area. Based on the information provided, the stormwater discharge from Outfall 014 is classified as not associated with industrial activity and, therefore, the discharge from it is not regulated. When not regulated, an outfall is removed from the permit.

If Dominion wishes Outfall 014 to be placed back into the permit, please submit a revision of Attachment G providing the correct designation of the outfall as being associated with industrial activity and ensure all sources within the drainage area are correctly identified.

Dominion Response: See enclosed revised Attachment G.

Part III.A.3.a We request that uncontaminated RO water, Uncontaminated demineralizer water, raw groundwater and raw lake water be added to the list of allowable non-stormwater discharges.

Lake water may be used for dust suppression at the facility.

Staff Response:

Staff believes raw groundwater is already addressed as an allowable non-stormwater discharge through the line item allowing for uncontaminated groundwater and, therefore, does not need to be added. Staff does not consider uncontaminated RO water and uncontaminated demineralizer water appropriate for inclusion as allowable non-stormwater discharges. Staff has no objection to the inclusion of raw lake water as an allowable non-stormwater discharge and has added it to Part III of the Draft Permit.

Dominion Response: We request that DEQ reconsider including uncontaminated demineralizer water as an allowable non-stormwater discharge. Its has been previously included in the Clover Power Station permit (VA0083097) and the Surry Power Station permit (VA0004090). No chemicals are added to this water.

Fact Sheet Item 26.c Third bullet: Outfall 014 has been removed since the stormwater discharge is not associated with industrial activities and thereby not regulated. We are requesting that the outfall be included in the permit.

Staff Response:

Attachment G (Supplemental Information) of Dominions application states Outfall 014 has no industrial activities associated with this drainage area. Based on the information provided, the stormwater discharge from Outfall 014 is classified as not associated with industrial activity and, therefore, the discharge from it is not regulated. When not regulated, an outfall is removed from the permit.

If Dominion wishes Outfall 014 to be placed back into the permit, please submit a revision of Attachment G providing the correct designation of the outfall as being associated with industrial

activity and ensure all sources within the drainage area are correctly identified.

Dominion Response: See enclosed revised Attachment G.

Fact Sheet Attachments Outfall 014 is a stormwater outfall associated with industrial activity.

Staff Response:

Attachment G (Supplemental Information) of Dominions application states Outfall 014 has no industrial activities associated with this drainage area. Based on the information provided, the stormwater discharge from Outfall 014 is classified as not associated with industrial activity and, therefore, the discharge from it is not regulated. When not regulated, an outfall is removed from the permit.

If Dominion wishes Outfall 014 to be placed back into the permit, please submit a revision of Attachment G providing the correct designation of the outfall as being associated with industrial activity and ensure all sources within the drainage area are correctly identified.

Dominion Response: See enclosed revised Attachment G. 0 (Outfall 014)

As indicated above, the description of this outfall receiving non-industrial run-off is incorrect and we request that it be revised.

Staff Response:

Attachment G (Supplemental Information) of Dominions application states Outfall 014 has no industrial activities associated with this drainage area. Based on the information provided, the stormwater discharge from Outfall 014 is classified as not associated with industrial activity and, therefore, the discharge from it is not regulated. When not regulated, an outfall is removed from the permit.

If Dominion wishes Outfall 014 to be placed back into the permit, please submit a revision of Attachment G providing the correct designation of the outfall as being associated with industrial activity and ensure all sources within the drainage area are correctly identified.

Dominion Response: See enclosed revised Attachment G. 0 (Outfall 021)

We request that the following be added to the outfall description: This outfall can also be used to drain down the entire RO system in the event of an emergency.

Staff Response:

Dominions application does not include the requested source. The information presented in the Fact Sheet is based on the information provided in the application Form 2C (Part 2.B.1) which does not include using Outfall 021 as a discharge location for the RO system in the event of an emergency.

Staff has no objection making the change upon receipt of a revised Form 2C that reflects the correct sources to the outfall. Staff also requests information as to the characterization of the emergency discharge to determine if any additional monitoring requirements are necessary for Outfall 021 based on the entire RO system discharge.

Dominion Response: See enclosed revised Form 2C.

0 (Outfall 103)

In the source description, we request that the service water high-capacity blowdown be changed to service water low-capacity blowdown.

Staff Response:

Form 2C (Part 2.B.1) of Dominions application states that the service water high-capacity blowdown is an operation contributing to the flow from Internal Outfall 103. The information presented in the Fact Sheet is based on the information provided in the application.

Staff has no objection making the change upon receipt of a revised Form 2C that reflects the correct sources to the outfall.

Dominion Response: See enclosed revised Form 2C. 0 (Outfall 105)

We request that the source description be changed to Bearing cooling blowdown, tower to tower operation (intermittent).

Staff Response:

Form 2C (Part 2.B.1) of Dominions application states that the operations contributing to the flow from Internal Outfall 105 consists of continuous blowdown and lake to lake operations (intermittent). The information presented in the Fact Sheet is based on the information provided in the application.

Staff has no objection making the change upon receipt of a revised Form 2C that reflects the correct sources to the outfall.

Dominion Response: See enclosed revised Form 2C. 0 (Outfall 103/104, 109/110, 112/113, and 108/115)

Please confirm that for substantially identical outfalls, data generated for one outfall can be used to represent the second outfall irrespective of which outfall was sampled. (Clarification received after the submittal of comments that Outfall 103 was a typographical error that should have read Outfall 013.

Staff Response:

Where two outfalls have been identified as substantially identical, the facility selects just one representative outfall to monitor the discharge and report the data as applicable for the substantially identical outfall. Sampling may not alternate amongst substantially identical outfalls as that may not provide a representative dataset. That is, if Internal Outfall 109 has been deemed representative of Internal Outfall 110, the data for Internal Outfall 109 may be submitted on the DMR for Internal Outfall 110. However, if Internal Outfall 110 is sampled the data cannot be deemed representative of Internal Outfall 109 and reported on the DMR for Internal Outfall 109.

Clarifying language has been added to Part I.A of the Draft Permit and Attachment 10 of the Fact Sheet. Staff requests that Dominion review the substantially identical outfalls identified within the permit and confirm which outfall has been deemed representative of the other.

Dominion Response: Revised outfall descriptions for substantially identical outfalls in the revised draft permit are correct except for the descriptions for Outfall 013 and Outfall 104. Currently, Outfall 104 is used to represent discharges for Outfall 013. Outfall 104 is a continuously discharging outfall whereas Outfall 013 discharges intermittently. We request that it be carried forward in the new permit.

EPA FORM 3510-2C (Rev. 8-90)

Please type or print in the unshaded areas only EPA ID Number (Copy from Item 1 of Form 1) 110001891114 Form Approved OMB No. 2040-0086 Approval expires 3-31-98 Form 2C NPDES U.S. ENVIRONMENTAL PROTECTION AGENCY APPLICATION FOR PERMIT TO DISCHARGE WASTEWATER EXISTING MANUFACTURING, COMMERCIAL, MINING AND SILVICUTLRAL OPERATIONS Consolidated Permits Program I. Outfall Location For this outfall, list the latitude and longitude of its location to the nearest 15 seconds and name of the receiving water.

Outfall Latitude Longitude Receiving Water (name)

Number (list)

Deg Min Sec Deg Min Sec 001 38 00 30.2

-77 43 43 Lake Anna 101 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 103 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 104 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 105 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 107 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 108 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 109 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 110 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 111 38 03 46

-77 47 13.4 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 112 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 113 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 114 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 115 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 116 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 117 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 118 38 03 5.8

-77 47 3.1 Discharge Canal to Waste Heat Treatment Facility to Lake Anna 009 38 03 43.6

-77 47 31 Lake Anna 013 38 03 43.6

-77 47 24.4 Lake Anna 016 38 03 43.6

-77 47 24.4 Lake Anna 020 38 03 43.6

-77 47 24.4 Lake Anna 021 38 03 43.6

-77 47 24.4 Lake Anna 028 38 03 39.2

-77 46 57.3 Lake Anna II. Flows, Sources of Pollution, and Treatment Technologies A.

Attach a line drawing showing the water flow through the facility. Indicate sources of intake water, operations contributing wastewater to effluent, and treatment units labeled to correspond to the more detailed descriptions in Item B. Construct a water balance on the line drawing by showing average flows between intakes, operations, treatment units, and outfalls. If a water balance cannot be determined (e.g. for certain mining activities), provide a pictorial description of the nature and amount of any sources of water and any collection or treatment measures. See Attachment B.

B.

For each outfall, provide a description of (1) all operations contributing wastewater to the effluent, including process wastewater, sanitary wastewater, cooling water, and stormwater runoff; (2) the average flow contributed by each operation; and (3) the treatment received by the wastewater. Continue on additional sheets if necessary.

1. Outfall Number

2. Operations Contributing Flow

3. Treatment

a. OPERATION (list)

b. AVERAGE FLOW

a. DESCRIPTION

b. LIST CODES FROM TABLE 2C-1 001 Discharges from the Waste Heat Treatment Facility (WHTF), which includes internal outfalls, at Dike 3 2440.52 MGD Discharge to Lake Anna 4-A 101 Condenser cooling water 1850.56 MGD Discharge to discharge canal 1-O 103 Process wastewater clarifier, including flow from the liquid radioactive waste management system, Steam generator blowdown, Package boiler blowdown, Mat sump system, Ion exchange waste, Sevice water system low capacity blowdown (intermittent) 0.288MGD Ion exchange; discharge to discharge canal 2-J 1-O 104 Turbine building sumps 1, 2, &3 Storm water, Fire water system line drains, Misc. discharges of purified or raw lake water from various infrequent plant maintenance activities, Chiller water, Service water, Condensate Storage Tanks, AST Containment Sump, Demineralizer Sump, Plant condensers, Bearing cooling water Temporary package boiler blowdown 0.288 MGD O/W separator; discharge to discharge canal Neutralization 1-H 2-K 1-O

EPA FORM 3510-2C (Rev. 8-90) 105 Bearing cooling tower blowdown

• Intermittent blowdown

• Tower to tower operation Intermittent 0.00281 MGD Discharge to discharge canal 1-O 107 Bearing Cooling System Discharge -

Lake to lake operation (intermittent)

Strainer blowdown Intermittent (has not discharged during 2015-2017 time period)

Discharge to discharge canal 1-O 108 Service water overboard Batch blowdown overflow Straight-through cooling water Header maintenance Intermittent (0.15 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-O 109 Hot well drain - Unit 1 Secondary system condenstate Intermittent (0.1368 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-O 110 Hot well drain - Unit 2 Secondary system condenstate Intermittent (0.1368 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-O 111 Unit 1 & 2 Sewage Ttreatment Plant 0.03 MGD design daily avg flow 0.00586 MGD daily avg flow See EPA Form 2A; Discharge to discharge canal 1-T, 1-L, XX, 3-A, 5-A, 1-U, 2-F 1-O 112 Steam generator blowdown - Unit 1 0.1872 MGD Discharge to discharge canal 1-O 113 Steam generator blowdown - Unit 2 0.1872 MGD Discharge to discharge canal 1-O 114 Service water tie-on vault drain Intermittent (0.00285 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-O 115 Service water system high capacity blowdown Intermittent (0.15 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-O 116 Vaccum Priming Pump 0.072 MGD Discharge to discharge canal 1-O 117 Salt storage pond Intermittent (0.47 MGD for the 2015-2017 time period)

Discharge to discharge canal 1-U 1-O 118 Beyond Design Basis Pumps/Portable Emergency Water Supply Pumps Intermittent (has not discharged during 2015-2017 time period)

Discharge to discharge canal 1-O 009 Settling pond: Groundwater; storm water; RO unit backwash; Bearing cooling tower water during maintenance activities; Ionics emergency shower wash post neutralization in holding tank 0.828 MGD Sedimentation; Discharge to Lake Anna 1-U, 4-A 013 Turbine building sumps #1 and #2, Stormwater, Plant condensers Bearing cooling water, Misc.

discharges of purified or raw lake water from various infrequent plant maintenance activities Intermittent (has not discharged during 2015-2017 time period)

Discharge to Lake Anna 4-A 016 Intake screen wash water 3.368 MGD Discharge to Lake Anna 4-A 020 Reverse Osmosis (RO) reject 0.1834MGD Discharge to Lake Anna 4-A 021 RO drain line (This outfall can also be used to drain down the entire RO system in the event of an emergency)

Intermittent (has not discharged during 2015-2017 time period)

Discharge to Lake Anna 4-A 028 Beyond Design Basis Pumps/Portable Emergency Water Supply Pumps Intermittent (0.384 MGD for the 2015-2017 time period)

Discharge to Lake Anna 4-A

EPA FORM 3510-2C (Rev. 8-90)

CONTINUED FROM THE FRONT C. Except for storm runoff, leaks, or spills, are any of the discharges described in Items II-A or B intermittent or seasonal?

X YES (complete the following table)

NO (go to Section III)

1.

OUTFALL NUMBER (list)

2. OPERATION(s)

CONTRIBUTING FLOW (list)

3. FREQUENCY

4. FLOW

a. DAYS PER WEEK (specify average)

b.

MONTHS PER YEAR (specify average)

a. FLOW RATE (in mgd)

b. TOTAL VOLUME (specify with units

c. DUR-ATION (in days)

1. LONG TERM AVERAGE

2. MAXIMUM DAILY

1. LONG TERM AVERAGE

2. MAXIMUM DAILY 107 Bearing Cooling System Discharge - Lake to lake operation (intermittent)

Strainer blowdown Varies Varies No discharge during 2015-2017 time period n/a 108 Service water overboard Batch blowdown overflow Straight-through cooling water Header maintenance Varies Varies 0.15 0.15 0.15 MG 0.15 MG 1

109 Hot well drain - Unit 1 Secondary system condenstate 1/ outage 1/ 18 months 0.1368 0.1368 0.1368 MG 0.1368 MG 1

110 Hot well drain - Unit 2 Secondary system condenstate 1/ outage 1/ 18 months 0.1368 0.1368 0.1368 MG 0.1368 MG 1

114 Service water tie-in vault drain Varies Varies 0.000285 0.000513 0.000285 MG 0.000513 MG 1

115 Service water system high capacity blowdown Varies Varies 0.15 0.15 0.15 MG 0.15 MG 1

117 Salt Storage Pond Varies Varies 0.47 1.15 0.47 MG 1.15 MG 1

118 Beyond Design Basis Pumps/Portable Emergency Water Supply Pumps Varies Varies No discharge during 2015-2017 time period n/a 013 Turbine building sumps #1 and

1. 2; stormwater Varies Varies No discharge during 2015-2017 time period n/a 021 RO drain line Varies Varies No discharge during 2015-2017 time period n/a 028 Beyond Design Basis Pumps/Portable Emergency Water Supply Pumps Varies Varies 0.384 0.384 0.384 MG 0.384 MG 1

III. PRODUCTION A. Does an effluent guideline limitation promulgated by EPA under Section 304 of the Clean Water Act apply to your facility?

X YES (complete Item III-B)

NO (go to Section IV)

B. Are the limitations in the applicable effluent guideline expressed in terms of production (or other measure of operation)?

YES (complete Item III-C)

X NO (go to Section IV)

C. If you answered "yes" to Item III-B, list the quantity which represents an actual measurement of your level of production, expressed in the terms and units used in the applicable effluent guideline, and indicate the affected outfalls.

1. AVERAGE DAILY PRODUCTION

2. AFFECTED OUTFALLS (list outfall numbers)

a. QUANTITY PER DAY

b. UNITS OF MEASURE

c. OPERATION, PRODUCT, MATERIAL, ETC.

(specify)

N/A IV. IMPROVEMENTS A. Are you now required by any Federal, State, or local authority to meet any implementation schedule for the construction, upgrading, or operation of wastewater treatment equipment or practices or any other environmental programs which may affect the discharges described in this application? This includes, but is not limited to, permit conditions, administrative or enforcement orders, enforcement compliance schedule letters, stipulations, court orders, and grant or loan conditions.

YES (complete the following table)

X NO (go to Item IV-B)

1. IDENTIFICATION OF CONDITION, AGREEMENT, ETC.

2. AFFECTED OUTFALLS

3. BRIEF DESCRIPTION OF PROJECT

4. FINAL COMPLIANCE DATE

a. NO.

b. SOURCE OF DISCHARGE

a. REQUIRED

b. PROJECTED N/A B. OPTIONAL: You may attach additional sheets describing any additional water pollution control programs (or other environmental projects which may affect your discharges) you now have underway or which you plan. Indicate whether each program is now underway or planned, and indicate your actual or planned schedules for construction.

MARK "X" IF DESCRIPTION OF ADDITIONAL CONTROL PROGRAM IS ATTACHED

EPA FORM 3510-2C (Rev. 8-90)

CONTINUED FROM PAGE 2 EPA ID Number (Copy from Item 1 of Form 1) 110001891114 V. INTAKE AND EFFLUENT CHARACTERISTICS A, B, & C:

See instructions before proceeding - Complete one set of tables for each outfall - Annotate the outfall number in the space provided.

NOTE: Tables V-A, V-B, and V-C are included on separate sheets number V-1 through V-9.

D: Use the space below to list any of the pollutants listed in Tables 2c-3 of the instructions, which you know or have reason to believe is discharged or may be discharged from any outfall. For every pollutant you list, briefly describe the reasons you believe it to be present and report any analytical data in your possession.

1. POLLUTANT

2. SOURCE

1. POLLUTANT

2. SOURCE No 2C-3 pollutants are known or believed to be discharged from any outfall.

VI. POTENTIAL DISCHARGES NOT COVERED BY ANALYSIS Is any pollutant listed in Item V-C a substance or a component of a substance which you currently use or manufacture as an intermediate or final product or byproduct?

X YES (list all such pollutants below)

NO (go to Item VI-B)

As radioactive releases at this facility are regulated by the Nuclear Regulatory Commission (NRC), they have not been listed here.

See Attachment C for a list of other potential discharges not covered by analysis.

NORTH ANNA POWER STATION VPDES Permit Renewal Application Supplemental Information FORM 1 The North Anna Power Station is a nuclear electric generating facility located in Louisa County, VA. The station is owned by Virginia Electric and Power Company and Old Dominion Electric Cooperative own the North Anna Power Station. Virginia Electric and Power Company d/b/a Dominion Energy Virginia operates the facility and is the VPDES permit holder.

ITEM 2E - HAZARDOUS WASTE The station may temporarily store hazardous waste for short periods of time in an accumulation area located on-site. Any accumulation and storage activities are conducted in accordance with the applicable requirements of 40 CFR 262. The current generator status for the station is a small quantity generator.

ITEM X -

In addition to the Units 1 and 2 related environmental permits listed in Part X, the facility holds the following authorizations:

Type of Permit Permit Number Issuing Agency Virginia Water Protection VWP10-1256 VA DEQ Impacts to Navigable Waters 10-V1256/NAO2008-2534 USACE Land disturbance ESCP30-80 Louisa County Water Supply Wells PWSID 2109600 (station wells)

PWSID 2109610 (NANIC well)

VDH, Louisa County Virginia Water Protection-Water Withdrawal VWP10-1496 VA DEQ ITEM XI-MAP A topographic map showing the location of the North Anna Power Station is included with this application. Additional drawings showing the outfall locations and other more detailed site features can be found in the aerial maps and also in site drawings included with application FORM 2F.

FORM 2C ITEM II-A: WATER FLOW BALANCE DIAGRAM The facilitys water flow balance diagram shows the general route taken by water from intake to discharge. An exact water balance cannot be provided because a substantial component of the water flow is derived from rainfall. Some water is also lost to evaporation. Additionally, water inflow and outflow are dependent upon time of year and generating output. The data used to generate the average flows shown on the diagram are described under Item V. below.

Item II-B: OUTFALL DESCRIPTION The North Anna Power Station's discharges are permitted by the Virginia Department of Environmental Quality as part of Individual Industrial Major VPDES Permit No. VA0052451. This VPDES permit combines both industrial wastewater and storm water discharges. The facility has several external process water outfalls that discharge to Lake Anna, in addition to internal outfalls that discharge to the Waste Heat Treatment Facility (WHTF).See list below.

EXTERNAL OUTFALLS Outfall 001: Discharge from Waste Heat Treatment Facility at Dike 3 Outfall 009: Groundwater, Stormwater, and Backwash from Sand Filters / Reverse Osmosis Unit Outfall 013: Turbine Building Sump #1 & #2 and Stormwater Outfall 016: Intake Screen Wash Water Outfall 020: Reverse Osmosis Reject Outfall 021: Reverse Osmosis Drain Line Outfall 028: Beyond Design Basis and Emergency Pumps discharge to Lake Anna INTERNAL OUTFALLS Outfall 101: Discharge of Condenser Cooling Water to the Discharge Canal Outfall 103: Process Waste Clarifier Outfall 104: Turbine Sumps 1, 2 & 3 and Stormwater Outfall 105: Bearing Cooling Tower Blowdown Outfall 107: Bearing Cooling System Discharge - Lake to Lake Operation Outfall 108: Service Water Overflow Outfall 109 & 110: Hot Well Drains 1&2 Outfall 111: Sewage Treatment Plant Outfall 112 & 113: Steam Generator Blowdown Units 1&2.

Outfall 114: Service Water Pipe Vault Drain Outfall 115: Service Water System Blowdown Outfall 116: Vacuum Priming Pumps Outfall 117: Salt Storage Pond Outfall 118: Beyond Design Basis and Emergency Pumps discharge to the Discharge Canal ITEMS V-A.B. & C: INTAKE AND EFFLUENT CHARACTERISTICS Samples used to generate the data included on Form 2C were collected during periods representative of facility operations by persons experienced in the sampling of industrial effluents. The samples were collected in accordance with procedures described in the instructions for Form 2C as modified by waivers approved by DEQ (See Attachment D). Sample analyses were performed in accordance with methods promulgated in 40 CFR Part 136, alternative approved methods, VPDES permit regulations, Attachment B requirements, and using sufficiently sensitive methods.

For DMR parameters that are routinely monitored under Part I of the current permit the existing discharge monitoring data for the period from January 1, 2015 through December 31, 2017 were used to produce the data included on Form 2C. For reported temperature data, winter temperatures were based on measurements taken from November to April. Summer temperatures were based on the measurements taken from June to September.

For non-DMR parameters, the data was collected in accordance with the approved sampling plan:

Outfalls 001, 009, 020, 104 and intake were sampled.

Outfall 104 was deemed substentially identical to Outfall 013, so outfall 104 data can be used for Outfall 013.

Outfall 021 was deemed substantially identical to the intake, so intake data can be used for Outfall 021.

For data reporting, and when analyzing a mixed data set (a mixture of real values and less than quantification level values), the less than quantification level value was treated as a zero in accordance with the DMR reporting requirements. In cases where all measured data were less than the quantification level, the mass loading was reported as less than the calculated value. When all data were less than the

quantification level and different quantification levels were achieved, the average concentration was reported as less than the highest quantification level achieved (e.g. if four sample results were <0.1,

<0.01, <0.001, and <0.005, the average and maximum concentrations were reported as <0.1).

ITEM VI: POTENTIAL DISCHARGES NOT COVERED BY ANALYSES Numerous chemicals are used in minor and bulk amounts at the station. A list of the bulk chemicals employed is included in Attachment C. Certain chemicals have multiple uses, and the stated purpose is not preclusive of other purposes or functions. Safety Data Sheets (SDSs) will be provided upon request.

Information on chemical use, material storage, and waste management are located below in the section of this form related to Form 2F.

In addition to the material discussed in this document, North Anna Power Station uses numerous chemicals to operate and maintain its equipment, vehicles, and facilities. Examples of these chemicals include lubricants, cleaners, detergents, polishes, waxes, cleaners, cutting oils, sanitizers, paints, solvents, and protectants. The majority of these chemicals are managed in small containers, but some are managed in larger quantities. It is conceivable that these chemicals and chemical types could appear in discharges from the North Anna Power Station at very low concentrations (i.e., below the level of detection).

FORM 2F ITEM IV.B: NARRATIVE DESCRIPTION OF POLLUTANT SOURCES North Anna Power Station has five stormwater outfalls; four storm water outfalls are associated with industrial activity, and one outfall with no industrial activities in its drainage area. All storm water outfalls and their associated drainage areas are shown on the site map included in Attachment E.

STORMWATER OUTFALLS:

Outfall 014 has a drainage area of approximately 4.3 acres, with approximately 3.7 acres of impervious area. Stormwater is collected from the western half of the Turbine Building and from around the SBO Diesel Building. Periodic plant maintenance activities occur in this area. It discharges to Lake Anna.

Outfall 022 has a drainage area of approximately 57.5 acres, with approximately 7.1 acres of impervious area. Stormwater collected from the higher portions near the old contractor shops, parking lots and the switchyard area, flows into a drop grating to a culvert near the northeast corner of the switchyard and discharges into Lake Anna. The lower, more level portion includes the old vehicle maintenance shop, the old paint shop (interim salt storage area) and part of an outdoor equipment laydown area. Stormwater runoff from the grassed portions around the shops and laydown areas, are collected in a swale which combines via culvert, with Outfall 022.

Outfall 024 has a drainage area of approximately 6.1 acres with primarily sheet flow runoff and approximately 0.08 acres of impervious area. The outfall receives flow from a field and an unpaved roadway. The stormwater is collected in a culvert and discharged to Lake Anna.

Outfall 025 has a drainage area of approximately 58.6 acres, with approximately 4 acres being impervious. This area includes a portion of the warehouse facilities, laydown area, and some small utility buildings. Stormwater from the northern portion of this drainage area is conveyed under the paved roadway via two culverts. The culvert to the west carries the smaller amount of stormwater flow which drains from grassy fields with no industrial activity. The culvert to the east is the sampling point for this outfall since it collects the stormwater associated with the above referenced industrial activities. This outfall discharges to the Waste Heat Treatment Facility.

Outfall 027 has a drainage area of approximately 7.5 acres, with approximately 1.3 acres being

impervious. This area includes a portion of the warehouse and storage facilities, hazardous material storage building, roadway and a fueling area. The area drains to a stormwater retention pond. The stormwater pond discharges over a riprap outfall to a drainage that discharges to the Waste Heat Treatment Facility. Materials are kept under cover with the exception of the fueling area. Stormwater from the fueling area is directed through an oil water separator prior to entering the stormwater pond.

North Anna Power Station implements a Storm Water Pollution Prevention Plan (SWPPP) that was developed in accordance with the current VPDES permit. Section 4 of the SWPPP included in Attachment F provides additional information on potential pollutant sources.

ITEM IV.C: NARRATIVE DESCRIPTION OF SIGNIFICANT MATERIALS, MATERIALS MANAGEMENT PRACTICES, AND EXISTING STRUCTURAL AND NONSTRUCTURAL CONTROLS Sections 5 and 6 of the SWPPP provide a detailed listing of significant materials and materials management practices.

In addition to the SWPPP, the station also implements an oil contingency plan in accordance with the Federal regulatory requirements for Spill Prevention Control, and Countermeasure (SPCC) Plans 40 CFR 112.1 - 112.15. The SPCC plan is a comprehensive description of the facility's containment and countermeasures that would prevent oil spills from occurring as well as procedures to respond to and clean up oil spills that do occur. The purpose of an SPCC Plan is to prevent oil spills from entering a waterway and must address the following three areas: 1) operating procedures that prevent and detect oil spills, 2) control measures installed to prevent a spill from reaching the environment, and 3) countermeasures to contain, clean up, and mitigate the effects of an oil spill that reaches the environment.

ITEM VII. PARTS A, B, C, D: DISCHARGE INFORMATION The data presented in Form 2F for Outfalls 022 and 025 was generated from grab samples collected following the initiation of qualified storm event discharges on August 20, 2018. According to Weather Sentry, the total rainfall amount for North Anna/ Louisa was 2.02 (> 0.1) on August 20, 2018. The previous qualifying rain event occurred on August 12, 2018 (>72 hours). No stormwater discharge flows were provided since Part D of this section pertains to composite stormwater samples.

Outfall 27 was previously sampled and the data was submitted to DEQ on May 2, 2017. Since the data was generated less than 3 years ago and since it is still representative of the discharge, a copy of the May 2, 2017 submittal is included with Form 2 F.

Effluent samples used to generate the data included in Form 2F were collected during periods representative of facility operations by persons experienced in the sampling of industrial effluents. The samples were collected in accordance with procedures described in the instructions for Form 2F and per the data generation strategy approved by DEQ. Sample analyses were performed in accordance with methods promulgated in 40 CFR Part 136 alternative approved methods, VPDES permit regulations, and using sufficiently sensitive methods.

FORM 2A The facilitys Sewage Treatment Plant discharges internally to the WHTF through Outfall 111.

DMR data for flow, pH, BOD, and TSS from January 1, 2015 to December 31, 2017 was used to complete Form 2A Section A.12. As for fecal coliform and temperature, three fecal coliform samples were collected and the discharge temperature was measured on three different days with two samples

/readings at least four months apart. The results are included in the tables below.

Date Fecal Coliform MPN/100 ml May 10, 2018

<2 September 25, 2018 2

October 3 2018

<2 Date STP Effluent Temperature

(°C)

May 10, 2018 21.4 September 25, 2018 24.1 October 4 2018 24.5 Please note that pages 10 to 21 of Form 2A were not included in this application as they are not applicable to this facility.

PERMIT REQUESTS

1. Installation of Motor Operated Valve to Control Releases from the Lake Anna Dam Description of Change:

A motor operated hydro unit bypass / throttle valve is being installed to provide an automated means of providing river flow when the hydro units are out of service. The MOV will receive a trip signal from the Hydro Units when they are not in service, which will automatically fully open the valve.

Additionally, electrical circuitry will ensure the valve trips open on a loss of power, since a Hydro Unit trip and a loss of power event often occur coincident. Since the valve alone can discharge flows much greater than 40 CFS, an orifice plate will be installed designed to discharge 43 CFS. Since the required discharge is a minimum of 40 CFS, designing the orifice plate to 43 CFS will provide adequate regulatory margin and ensure release of the minimum required flow. The valve will be also used to throttle flow during drought conditions during which the Operator will slowly decrease the lake discharge to 20 cfs in accordance with North Annas VPDES. Since the flow is based on the static pressure head between the lake level and the piping discharge, this configuration will require much less adjustments when small lake level fluctuations occur. Physical installation of the valve was completed the week of October 1, 2018; however, the electrical components have yet to be installed and manual adjustments of the valve would be the only possible method of operation at this time. The valve has not been operated to date.

Part I.D.3. of North Anna Power Stations current VPDES permit requires that Lake Anna dam gate adjustments be performed in accordance with the DEQ-approved Station Operating Procedure (SOP).

The existing DEQ-approved SOP has been revised to recognize the new MOV as the preferred method of achieving minimum flow during periods without operation of the hydro units. The revised SOP is included with this application for review and approval by DEQ.

2. Stormwater Outfall 024 There are no industrial activities in Outfall 024s drainage area. We request that the stormwater outfall be recognized in the permit with no monitoring requirements during the next permit term.

3. Outfall 117 Annual DMR Part I G. 22.c.2. of North Anna Power Stations current VPDES permit requires that the flow and the number of days of discharge for Outfall 117 be submitted with the DMR of the month in which the discharge took place. However, the only e-DMR that was provided for this outfall is the annual e-DMR. We request that either the condition be revised to allow the annual submittal of the data, or include a monthly e-DMR for outfall 117.

4. Toxicity Monitoring Reporting Whereas, Part I C.1.f. of North Anna Power Stations current VPDES permit requires the submittal of the toxicity test results and report with the monthly e-DMR for the month following the receipt of the report, Part I C.2. requires that the toxicity test results and report be submitted with the annual e-DMR by January 10 for the preceding year. We request that either Part I C.1.f. permit condition be deleted, or include a monthly e-DMR for toxicity test reporting.

North Anna Power Station Main Dam Spillway Gate Standard Operating Procedure Maintaining VPDES Permit Minimum Discharge Introduction The Station Operating Procedure (SOP) has been revised and is being submitted to the Department of Environmental Quality (DEQ) Northern Regional Office for review and approval. The SOP reflects the use of both engineering calculations and the flow gauging station on the North Anna River downstream of the Lake Anna dam (USGS 01670400), with the target of achieving the flow releases of 40 cubic feet per second (cfs) and below.

Bypass Valve and Gate Information

1. Hydro Unit Bypass Valve (bypass valve) is used to provide minimum flow when the hydro units are not in operation.

2. Skimmer Gate 1 (SG1) feeds the penstock to both hydro units and the bypass valve.

3. Skimmer Gate 2 (SG2) is used as a backup to provide minimum flow when bypass valve is out of service and hydro units are not in operation.

General Overview The small hydro unit (hereafter referred to as the hydro unit), when in operation, provides approximately 44 cfs when the lake level is between 248.1 msl and 250.0 msl. Alternatively, if the hydro unit is out of service, the bypass valve is operated to provide the minimum flow, with SG2 providing a backup means to achieve required flow. The hydro unit is used to discharge water until lake level reaches 248.1 msl.

At 248 msl the hydro unit is removed from service and the bypass valve is used to start reducing flow in accordance with the lake level contingency plan. Flows are reduced from 40 cfs to 20 cfs using the bypass valve, with SG2 as a backup means of reducing flow.

Maintaining Minimum 40 cfs Discharge Both engineering calculated valve or gate positions and USGS 01670400 gauging station will be used to ensure a minimum discharge of 40 cfs is maintained at all times. The hydro unit normally operates providing the minimum discharge release of 40 cfs when the lake level is between 248.1 msl and 250.1 msl. Station personnel will continue to monitor the flows recorded by USGS Gauging Station No.

01670400. The USGS Richmond Virginia office will be notified of any changes (i.e., > plus or minus 20 percent) of recorded flows from the gauging station that do not correspond to the expected flow with the hydro unit in service, bypass valve position, or gate position.

If the hydro unit is out of service, the bypass valve will be opened; ensuring the required minimum discharge release of 40 cfs is met. As with the hydro unit operation the USGS Richmond Virginia office will be notified of any changes (i.e., > plus or minus 20 percent) of recorded flows from the gauging station that do not correspond to the expected flow based on the bypass valve position.

Maintaining Minimum 20 cfs Discharge with Lake level < 248 msl Both engineering calculated valve or gate positions and USGS 01670400 gauging station will be used to ensure flow reductions from Lake Anna. The hydro units are offline and flows are controlled using the bypass valve. Adjustments below 40 cfs will occur in 5 cfs increments (i.e.

35 cfs, 30 cfs, 25 cfs, and 20 cfs), not to decrease below 20 cfs.

A graduated step scale is mounted to the top of SG 2 that provides the gate position below the surface of the water. As lake level decreases SG 2 is adjusted accordingly to maintain the proper

gate position to meet required discharge flow. Station personnel will continue to monitor the flows recorded by USGS Gauging Station No. 01670400. The USGS Richmond Virginia office will be notified of any changes (i.e., > plus or minus 20 percent) of recorded flows from the gauging station that do not correspond to the expected flow following changes from SG 2 positions.

Technical References

1. UFSAR 3.8.3, Main Dam

2. VPDES Permit No. 0052451Special Conditions - Lake Level Contingency Plan

3. TRM 3.7.4, North Anna Reservoir

4. 0-OP-59.1, Reservoir Spillway

5. 0-OP-59.5, Reservoir Discharge Control During Drought Conditions USGS Provisional Data Statement Data are provisional and subject to revision until they have been thoroughly reviewed and received final approval. Current condition data relayed by satellite or other telemetry are automatically screened to not display improbable values until they can be verified. Provisional data may be inaccurate due to instrument malfunctions or physical changes at the measurement site. Subsequent review based on field inspections and measurements may result in significant revisions to the data. Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Information concerning the accuracy and appropriate uses of these data or concerning other hydrologic data may be obtained from the USGS.