Text

Transmittal of NPDES Permit Issuance
	ML21337A379
Person / Time
Site:	Vogtle
Issue date:	12/03/2021
From:	Agee S; Southern Nuclear Operating Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	ND-21-1016
	Download: ML21337A379 (111)
	v • d • e

Southern Nuclear December 3, 2021 Docket Nos.: 52-025 ND-21-1016 52-026 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Southern Nuclear Operating Company Vogtle Electric Generating Plant Units 3 and 4 Transmittal of NPDES Permit Issuance ladies and Gentlemen:

In accordance with Section 3.0 of the Vogtle Electric Generating Plant (VEGP) Environmental Protection Plan (Units 3 and 4), Appendix B to Combined Operating licenses NPF-91 and NPF-92 respectively, enclosed is a copy of the VEGP Units 3 and 4 National Pollutant Discharge Elimination System (NPDES) Permit No. GA0039420 permit issuance. contains a copy of the permit issuance for Vogtle Units 3 and 4.

This letter contains no regulatory commitments. This letter has been reviewed and determined not to contain security-related information.

If you have any questions, please contact Ms. Stephanie Agee at (205) 992-7556.

Respectfully submitted, l!:t:/:!k Interim Manager, Regulatory Affairs Southern Nuclear Operating Company

Enclosure:

1) Vogtle Electric Generating Plant Units 3 and 4 National Pollutant Discharge Ehm1nat1on System Permit No. GA0039420 Permit Issuance

U.S. Nuclear Regulatory Commission ND-21-1016 Page 2 of 3 cc:

Southern Nuclear Operating Company / Georgia Power Company Mr. S. E. Kuczynski (w/o enclosures)

Mr. P. P. Sena III (w/o enclosures)

Mr. H. Nieh (w/o enclosures)

Mr. G. Chick Mr. S. Stimac Mr. P. Martino Mr. J. B. Williams Mr. D. L. McKinney (w/o enclosures)

Mr. T. W. Yelverton (w/o enclosures)

Mr. B. H. Whitley Mr. W. Levis Ms. C. A. Gayheart Ms. M. Ronnlund Mr. J. M DeLano Mr. M. J. Yox Mr. T. H. Arnette Mr. H. E. Curry Mr. C. T. Defnall Mr. J. Tupik Ms. A. C. Chamberlain Mr. S. Leighty Ms. K. Roberts Mr. J. Haswell Mr. D. T. Blythe Mr. K. Warren Mr. A. S. Parton Mr. A. Nix Ms. K. S. Dye Mr. S. M. Hoque Document Services RTYPE: VND.LI.L00 File AR.01.02.06 Nuclear Regulatory Commission Mr. M. King (w/o enclosures)

Mr. G. Bowman Ms. M. Bailey (w/o enclosures)

Ms. A. Veil Mr. G.J. Khouri Mr. G. Armstrong Mr. C. Patel Mr. C. Santos Mr. B. Kemker Mr. J. Eargle Mr. C. J. Even Ms. N. C. Coovert

U.S. Nuclear Regulatory Commission ND-21-1016 Page 3 of 3 Nuclear Regulatory Commission continued Mr. C. Welch Mr. J. Gaslevic Mr. O. Lopez-Santiago Mr. M. Webb Mr. B. Gleaves Mr. V. Hall Mr. T. Fredette Ms. K. McCurry Mr. B. Davis Mr. J. Parent Mr. B. Griman Mr. P. OBryan State of Georgia Mr. R. Dunn Oglethorpe Power Corporation Mr. M. W. Price Mr. B. Brinkman Mr. E. Rasmussen Municipal Electric Authority of Georgia Mr. J. E. Fuller Mr. S. M. Jackson Dalton Utilities Mr. T. Bundros Westinghouse Electric Company, LLC Mr. L. Oriani, Ph.D. (w/o enclosures)

Mr. T. Rubenstein (w/o enclosures)

Mr. M. Corletti Mr. D. Hawkins Mr. J. Coward Other Mr. S. W. Kline, Bechtel Power Corporation Ms. L. A. Matis, Tetra Tech NUS, Inc.

Mr. W. R. Jacobs, Jr., Ph.D., GDS Associates, Inc.

Mr. S. Roetger, Georgia Public Service Commission Mr. R. L. Trokey, Georgia Public Service Commission Mr. K. C. Greene, Troutman Sanders Mr. S. Blanton, Balch Bingham

Southern Nuclear Operating Company ND-21-1016 Enclosure 1 Vogtle Electric Generating Plant (VEGP) Units 3 and 4 National Pollutant Discharge Elimination System Permit No. 0039420 Permit Issuance (Enclosure 1 consists of 108 pages, including this cover page)

ENvlRONMENTALPROTECTION DMSION Summary Page Name of Facility Vogtle Electric Generating Plant, Units 3 & 4 NPDES Permit No. GA0039420 This permit is a reissuance of an NPDES permit for Vogtle Electric Generating Plant, Units 3 & 4.

The facility generates electricity through the use of nuclear fuel and discharges an average of 12.7 MGD of cooling tower blowdown, low volume wastewater, and intake screen backwash. This facility discharges to the Savannah River (Outfalls 001 and 011) in the Savannah River Basin. The permit expired on September 30, 2020 and became administratively extended.

The permit was placed on public notice from September 15, 2021 to October 15, 2021.

Please Note The Following Changes to the Proposed NPDES Permit From The Existing Permit Part I.A.1. - Effluent Limitations and Monitoring Requirements (External Outfall 001)

Modified the flow monitoring sample type from continuous to estimation. Outfall 001 does not have a flow meter and final discharge flow is calculated using the flow values measured at internal outfalls.

Added a daily maximum instream temperature monitoring requirement and a daily maximum temperature differential limit of +5 to be achieved at the edge of an approved mixing zone.

Added an intake temperature monitoring requirement to determine compliance with the temperature differential limit.

Added CBOD5 monitoring during the months of March - October to ensure that the facilitys contribution of oxygen-demanding substances remains de minimis.

Added total phosphorus monitoring per the Strategy for Addressing Phosphorus in NPDES Permitting.

Added chronic WET testing in accordance with EPDs Whole Effluent Toxicity (WET)

Strategy.

Part I.A.2. - Effluent Limitations and Monitoring Requirements (Internal Outfalls 002 and 003)

Added a weekly flow reporting requirement.

Part I.A.3. - Effluent Limitations and Monitoring Requirements (Internal Outfalls 004 and 005)

Added a 2/Month flow reporting requirement.

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 1

ENvlRONMENTALPROTECTION DMSION Summary Page Part I.A.4. - Effluent Limitations and Monitoring Requirements (Internal Outfalls 006 and 007)

Added a quarterly flow reporting requirement.

Part III.C - Special Conditions Paragraphs 3, 9, 10, and 11 have been removed based on best professional judgement.

Added 316(b) requirements applicable to cooling water intake structures for new facilities.

Other Removed internal outfall nos. 008 and 009 which are now routed to internal outfalls 002 and 003; respectively.

Removed outfall nos. 002A and 003A based on modified site operational procedures and piping reconfigurations.

Standard Conditions & Boilerplate Modifications The permit boilerplate includes modified language or added language consistent with other NPDES permits.

Final Permit Determinations and Public Comments Final issued permit did not change from the draft permit placed on public notice.

Public comments were received during public notice period.

Public hearing was held.

Final permit includes changes from the draft permit placed on public notice. See attached permit revisions and/or permit fact sheet revisions document(s)

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 2

Richard E. Dunn, Director EPD Directors Office 2 Martin Luther King, Jr. Drive Suite 1456, East Tower Atlanta, Georgia 30334 404-656-4713 Mr. Jim Delano, Environmental Affairs Manager Southern Nuclear Operating Company 11/04/2021 Vogtle Electric Generating Plant, Units 3 & 4 3535 Colonnade Parkway BIN N-218-EC Birmingham, Alabama 35243 RE: Permit Issuance Vogtle Electric Generating Plant, Units 3 & 4 NPDES Permit GA0039420 Burke County, Savannah River Basin

Dear Mr. Delano:

Pursuant to the Georgia Water Quality Control Act, as amended, the Federal Clean Water Act, as amended, and the Rules and Regulations promulgated thereunder, we have issued the attached permit for the above-referenced facility.

Your facility has been assigned to the following EPD office for reporting and compliance.

Signed copies of all required reports shall be submitted to the following address:

Environmental Protection Division Watershed Protection Branch Watershed Compliance Program 2 Martin Luther King Jr. Drive, Suite 1152 Atlanta, Georgia 30334 Please be advised that on and after the effective date indicated in the permit, the permittee must comply with all terms, conditions, and limitations of the permit. If you have questions concerning this correspondence, please contact Ian McDowell at 470.604.9483 or ian.mcdowell@dnr.ga.gov.

Sincerely, Richard E. Dunn Director RED:im Enclosure(s): Final Permit, Permit Fact Sheet with Appendices CC: EPD Watershed Compliance Program - Elizabeth Smith (elizabeth.smith@dnr.ga.gov)

U.S. EPA Region 4, via email: R4NPDESPermits@epa.gov EPD Watershed Planning and Monitoring Program - Josh Welte and Tyler Parsons (via email)

Permit No. GA0039420 Issuance Date:11/04/2021 National Pollutant Discharge Elimination System Permit In accordance with the provisions of the Georgia Water Quality Control Act (Georgia Laws 1964,

p. 416, as amended), hereinafter called the State Act; the Federal Water Pollution Control Act, as amended (33 U.S. C. 1251 et seq.), hereinafter called the Federal Act; and the Rules and Regulations promulgated pursuant to each of these Acts, Southern Nuclear Operating Company 3535 Colonnade Parkway BIN N-218-EC Birmingham, Alabama 35243 is issued a permit to discharge from a facility located at Vogtle Electric Generating Plant, Units 3 & 4 7821 River Road Waynesboro, Georgia 30830 Burke County to receiving waters Savannah River (external outfall nos. 001 and 011) in the Savannah River Basin.

in accordance with effluent limitations, monitoring requirements and other conditions set forth in the permit.

This permit is issued in reliance upon the permit application signed on March 31, 2020, August 12, 2021, any other applications upon which this permit is based, supporting data entered therein or attached thereto, and any subsequent submittal of supporting data.

This permit shall become effective on December 01, 2021.

This permit and the authorization to discharge shall expire at midnight November 30, 2026.

Richard E. Dunn, Director Environmental Protection Division

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 2 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 PART I A.1. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from external outfall number 0011 (33.148055, -81.752500) - Final Plant Discharge.

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

Discharge Monitoring Limitations Requirements2 Effluent Mass Based Concentration Characteristics (lbs/day) Based (mg/L) Measurement Sample Sample (Units)

Daily Daily Daily Daily Frequency Type Location Avg. Max. Avg. Max.

Final Flow (MGD) Report Report Daily Estimation3 Effluent Intake Temperature Report 1/Quarter Grab Intake

()4 Downstream Report 1/Quarter Grab Instream5 Temperature ()4,5 Delta Temperature4,5

+5 1/Quarter Calculation4

()

CBOD5 Final Report Report 1/Month Grab (Mar. - Oct.) Effluent Final Total Phosphorus Report Report 1/Month Grab Effluent Chronic Whole Final Report Report See Footnote6 Composite Effluent Toxicity6 Effluent The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored once per week by grab sample.

1 There shall be no discharge of floating solids, oil, scum or visible foam other than trace amounts.

2 All the parameters must be monitored, at a minimum, at the measurement frequency stated above if there is any discharge. If there is no discharge, state such in the discharge monitoring report in accordance with the reporting requirements in Part 1.D of this permit.

3 Flow shall be estimated using the summation of flows measured at internal outfalls 002, 003, 004, 005, 006, 007, and 010. An alternative method for determining flow rate may be used upon approval.

4 The temperature monitoring requirements shall become effective upon the commencement of commercial operations for Unit 3. Temperature measurements shall be taken between the hours of 9:00 a.m. and 3:00 p.m. and shall be taken on the same day. The temperature differential shall be calculated as the downstream temperature minus the intake temperature.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 3 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 5

See Special Conditions, Part III.C.7 of this permit. If the temperature sampled at the downstream edge of the mixing zone exceeds 90 , EPD may modify the permit to include an effluent limitation for temperature.

6 Chronic WET testing shall be conducted once during the permit term, and the results submitted to the EPD in accordance with Part I.D of the permit. An additional WET test shall be conducted and submitted with the subsequent permit application. The testing must comply with the most current U.S.

Environmental Protection Agency (EPA) chronic aquatic testing manuals. The referenced document is entitled Short-Term Methods of Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, 4th Edition, U.S. EPA, 821-R-02-013, October 2002. Definitive tests must be run on the same samples concurrently using both an invertebrate species (i.e., Ceriodaphnia dubia) and a vertebrate species (i.e., Fathead Minnow, Pimephales promelas) and shall include a dilution equal to the facilitys instream waste concentration (IWC) of 2.44%.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 4 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 A.2. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from internal outfall numbers 002 and 003 - Unit 3 Cooling Tower Blowdown / Service Water System Cooling Blowdown (002) and Unit 4 Cooling Tower Blowdown / Service Water System Cooling Tower Blowdown (003).

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

Discharge Monitoring Limitations Requirements1 Effluent Mass Based Concentration Characteristics (lbs/day) Based (mg/L) Measurement Sample Sample (Units)

Daily Daily Daily Daily Frequency Type Location Avg. Max. Avg. Max.

See Flow (MGD) Report Report 1/Week Continuous Footnote5 Free Available Multiple See 0.2 0.5 1/Week Chlorine (FAC)2 Grabs3 Footnote5 Total Residual Multiple See Report Report 1/Week Chlorine (TRC)2 Grabs3 Footnote5 FAC/TRC Discharge See Time2 Report 1/Week Calculation Footnote5 (minutes/day/unit)

See Chromium, Total4 0.2 0.2 1/Quarter Grab Footnote5 See Zinc, Total4 1.0 1.0 1/Quarter Grab Footnote5 1

All the parameters must be monitored, at a minimum, at the measurement frequency stated above if there is any discharge. If there is no discharge, state such in the discharge monitoring report in accordance with the reporting requirements in Part 1.D of this permit.

2 See Special Conditions, Part III.C.1 of this permit.

3 Multiple grab samples are to be collected on 15-minute intervals during periods of FAC/TRC discharges attributable to cooling tower chlorination.

4 See Special Conditions, Part III.C.2 of this permit.

5 The permittee shall sample and analyze the discharge from each internal outfall prior to mixing with any other wastestream.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 5 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 A.3. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from internal outfall numbers 004 and 0053 - Units 3 & 4 Waste Water Retention Basins.

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

Discharge Monitoring Limitations Requirements1 Effluent Mass Based Concentration Characteristics (lbs/day) Based (mg/L) Measurement Sample Sample (Units)

Daily Daily Daily Daily Frequency Type Location Avg. Max. Avg. Max.

See Flow (MGD) Report Report 2/Month Continuous Footnote2 Total Suspended See 30.0 100.0 2/Month Grab Solids Footnote2 See Oil and Grease 15.0 20.0 2/Month Grab Footnote2 1

All the parameters must be monitored, at a minimum, at the measurement frequency stated above if there is any discharge. If there is no discharge, state such in the discharge monitoring report in accordance with the reporting requirements in Part 1.D of this permit.

2 The permittee shall sample and analyze the discharge from each internal outfall prior to mixing with any other wastestream.

3 See Special Conditions, Part III.C.5 of this permit.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 6 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 A.4. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from internal outfall numbers 006 and 0074 - Units 3 & 4 Liquid Radwaste Systems Discharge.

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

Discharge Monitoring Limitations Requirements1 Effluent Mass Based Concentration Characteristics (lbs/day) Based (mg/L) Measurement Sample Sample (Units)

Daily Daily Daily Daily Frequency Type Location Avg. Max. Avg. Max.

See Flow (MGD) Report Report 1/Quarter Estimation2 Footnote3 Total Suspended See 30.0 100.0 1/Quarter Grab Solids Footnote3 See Oil and Grease 15.0 20.0 1/Quarter Grab Footnote3 1

All the parameters must be monitored, at a minimum, at the measurement frequency stated above if there is any discharge. If there is no discharge, state such in the discharge monitoring report in accordance with the reporting requirements in Part 1.D of this permit.

2 Flow shall be estimated by calculating the average daily flow based on the volume of the actual discharges. The flow calculation shall be documented and retained on-site. An alternative method for determining flow-rate may be used upon approval.

3 The permittee shall sample and analyze the discharge from each internal outfall prior to mixing with any other wastestream.

4 The radioactive component of this discharge is regulated by the US Nuclear Regulatory Commission (10 CFR Part 20)

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 7 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 A.5. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from internal outfall number 010 - Radwaste Dilution Flow.

1 The discharge shall consist only of river water with no additives.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 8 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 A.6. Effluent Limitations and Monitoring Requirements During the period specified on the first page of this permit, the permittee is authorized to discharge from external outfall number 0111,2 (33.154722, -81.758888) - Intake Screen Backwash.

1 There shall be no discharge of floating solids, oil, scum or visible foam other than trace amounts.

2 The discharge shall consist only of intake screen backwash. The permittee shall take all reasonable steps to minimize any adverse impact to waters of the State.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 9 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 B. Monitoring

1. Representative Sampling Samples and measurements taken as required herein shall be representative of the volume and nature of the monitored discharge. The permittee shall maintain a written sampling plan and schedule onsite.

2. Sampling Period

a. Unless otherwise specified in this permit, quarterly samples shall be taken during the periods January-March, April-June, July-September, and October-December.

b. Unless otherwise specified in this permit, semiannual samples shall be taken during the periods January-June and July-December.

c. Unless otherwise specified in this permit, annual samples shall be taken during the period of January-December.

3. Monitoring Procedures Analytical methods, sample containers, sample preservation techniques, and sample holding times must be consistent with the techniques and methods listed in 40 CFR Part 136. The analytical method used shall be sufficiently sensitive. EPA-approved methods must be applicable to the concentration ranges of the NPDES permit samples.

4. Detection Limits All parameters will be analyzed using the appropriate detection limits. If the results for a given sample are such that a parameter is not detected at or above the specified detection limit, a value of "NOT DETECTED" will be reported for that sample and the detection limit will also be reported.

5. 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 or measurements, and the person(s) performing the sampling or the measurements;

b. The dates and times the analyses were performed, and the person(s) performing the analyses;

c. The analytical techniques or methods used;

d. The results of all required analyses.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 10 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

6. Additional Monitoring by Permittee If the permittee monitors any pollutant at the location(s) designated herein more frequently than required by this permit, using approved analytical methods as specified above, the results of such monitoring shall be included in the calculation and reporting of the values required in the Discharge Monitoring Report. Such increased monitoring frequency shall also be indicated. EPD may require, by written notification, more frequent monitoring or the monitoring of other pollutants not required in this permit.

7. Records Retention The permittee shall retain records of all monitoring information, including all records of analyses performed, calibration and maintenance of instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit, for a minimum of three (3) years from the date of the sample, measurement, report or application, or longer if requested by EPD.

8. Penalties The Federal Clean Water Act and the Georgia Water Quality Control Act provide that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit, makes any false statement, representation, or certification in any record or other document submitted or required to be maintained under this permit, including monitoring reports or reports of compliance or noncompliance shall, upon conviction, be punished by a fine or by imprisonment, or by both.

The Federal Clean Water Act and the Georgia Water Quality Control Act also provide procedures for imposing civil penalties which may be levied for violations of the Act, any permit condition or limitation established pursuant to the Act, or negligently or intentionally failing or refusing to comply with any final or emergency order of the Director of EPD

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 11 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 C. Definitions

1. The "daily average" mass means the total discharge by mass 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 this permit, the daily average discharge shall be determined by the summation of all the measured daily discharges by weight divided by the number of days sampled during the calendar month when the measurements were made.

2. The "daily maximum" mass means the total discharge by mass during any calendar day.

3. The "daily average" concentration means the arithmetic average of all the daily determinations of concentrations made during a calendar month. Daily determinations of concentration made using a composite sample shall be the concentration of the composite sample.

4. The "daily maximum" concentration means the daily determination of concentration for any calendar day.

5. A calendar day is defined as any consecutive 24-hour period.

6. "Bypass" means the intentional diversion of waste streams from any portion of a treatment facility.

7. "Severe property damage" means substantial physical damage to property, damage to treatment facilities that causes them to become inoperable, or substantial and permanent loss of natural resources that 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.

8. EPD as used herein means the Environmental Protection Division of the Department of Natural Resources.

9. State Act as used herein means the Georgia Water Quality Control Act (Official Code of Georgia Annotated; Title 12, Chapter 5, Article 2).

10. Rules as used herein means the Georgia Rules and Regulations for Water Quality Control.

11. Cooling water intake structure means the total physical structure and any associated constructed waterways used to withdraw cooling water from waters of the United States.

The cooling water intake structure extends from the point at which water is first withdrawn from waters of the United States up to, and including the intake pumps.

12. Commercial Operation means the date after which the Unit is fully dispatchable on demand at the stated Net Electrical Output of 1,102 MWe of the Unit.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 12 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 D. Reporting Requirements

1. The permittee must electronically report the DMR, OMR and additional monitoring data using the web based electronic NetDMR reporting system, unless a waiver is granted by EPD.

a. The permittee must comply with the Federal National Pollutant Discharge Elimination System Electronic Reporting regulations in 40 CFR §127. The permittee must electronically report the DMR, OMR, and additional monitoring data using the web based electronic NetDMR reporting system online at:

https://netdmr.epa.gov/netdmr/public/home.htm

b. Monitoring results obtained during the calendar month shall be summarized for each month and reported on the DMR. The results of each sampling event shall be reported on the OMR and submitted as an attachment to the DMR.

c. The permittee shall submit the DMR, OMR and additional monitoring data no later than 11:59 p.m. on the 15th day of the month following the sampling period.

d. All other reports required herein, unless otherwise stated, shall be submitted to the EPD Office listed on the permit issuance letter signed by the Director of EPD.

2. No later than December 21, 2025, the permittee must electronically report the following compliance monitoring data and reports using the online web based electronic system approved by EPD, unless a waiver is granted by EPD:

a. CWA Section 316(b) Annual Reports;

b. Sewer Overflow/Bypass Event Reports;

c. Noncompliance Notification;

d. Other noncompliance; and

e. Bypass

3. Other Reports All other reports required in this permit not listed above in Part I.D.2 or unless otherwise stated, shall be submitted to the EPD Office listed on the permit issuance letter signed by the Director of EPD.

4. Other Noncompliance All instances of noncompliance not reported under Part I.B. and Part II. A. shall be reported to EPD at the time the monitoring report is submitted.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 13 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

5. Signatory Requirements All reports, certifications, data or information submitted in compliance with this permit or requested by EPD must be signed and certified as follows:

a. Any State or NPDES Permit Application form submitted to the EPD shall be signed as follows in accordance with the Federal Regulations, 40 C.F.R. 122.22:

1. For a corporation, by a responsible corporate officer. A responsible corporate officer means:

i a president, secretary, treasurer, or vice president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision making functions for the corporation, or ii. the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or having gross annual sales or expenditures exceeding $25 million (in second-quarter 1980 dollars), if authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures.

2. For a partnership or sole proprietorship, by a general partner or the proprietor, respectively; or

3. For a municipality, State, Federal, or other public facility, by either a principal executive officer or ranking elected official.

b. All other reports or requests for information required by the permit issuing authority shall be signed by a person designated in (a) above or a duly authorized representative of such person, if:

1. The representative so authorized is responsible for the overall operation of the facility from which the discharge originates, e.g., a plant manager, superintendent or person of equivalent responsibility;

2. The authorization is made in writing by the person designated under (a) above; and

3. The written authorization is submitted to the Director.

c. Any changes in written authorization submitted to the permitting authority under (b) above which occur after the issuance of a permit shall be reported to the permitting authority by submitting a copy of a new written authorization which meets the requirements of (b) and (b.1) and (b.2) above.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 14 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

d. Any person signing any document under (a) or (b) above shall make the following certification:

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted.

Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 15 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 PART II A. Management Requirements

1. Notification of Changes

a. The permittee shall provide EPD at least 90 days advance notice of any planned physical alterations or additions to the permitted facility that meet the following criteria:

1. 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);

2. 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); or

3. The alteration or addition results in a significant change in the permittees sludge use or disposal practices, and such alteration, addition, or change may justify the application of permit conditions that are different from or absent in the existing permit, including notification of additional use or disposal sites not reported during the permit application process or not reported pursuant to an approved land application plan.

b. The permittee shall give at least 90 days advance notice to EPD of any planned changes to the permitted facility or activity which may result in noncompliance with permit requirements.

c. Following the notice in paragraph a. or b. of this condition the permit may be modified. The permittee shall not make any changes, or conduct any activities, requiring notification in paragraph a. or b. of this condition without approval from EPD.

d. The permittee shall provide at least 30 days advance notice to EPD of:

1. any planned expansion or increase in production capacity; or

2. any planned installation of new equipment or modification of existing processes that could increase the quantity of pollutants discharged or result in the discharge of pollutants that were not being discharged prior to the planned change if such change was not identified in the permit application(s) upon which this permit is based and for which notice was not submitted under paragraphs a. or b. of this condition.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 16 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

e. All existing manufacturing, commercial, mining, and silvicultural dischargers shall notify EPD as soon as it is known or there is reason to believe that any activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any toxic pollutant not limited in the permit, if that discharge will exceed (i) 100 µg/L, (ii) five times the maximum concentration reported for that pollutant in the permit application, or (iii) 200 µg/L for acrolein and acrylonitrile, 500 g/L for 2,4 dinitrophenol and for 2-methyl-4-6-dinitrophenol, or 1 mg/L antimony.

f. All existing manufacturing, commercial, mining, and silvicultural dischargers shall notify EPD as soon as it is known or there is reason to believe that any activity has occurred or will occur which would result in any discharge on a nonroutine or infrequent basis, of any toxic pollutant not limited in the permit, if that discharge will exceed (i) 500 µg/L, (ii) ten times the maximum concentration reported for that pollutant in the permit application, or (iii) 1 mg/L antimony.

g. Upon the effective date of this permit, the permittee shall submit to EPD an annual certification in June of each year certifying whether or not there has been any change in processes or wastewater characteristics as described in the submitted NPDES permit application that required notification in paragraph a., b., or d. of this condition. The permittee shall also certify annually in June whether the facility has received offsite wastes or wastewater and detail any such occurrences.

2. Noncompliance Notification If, for any reason, the permittee does not comply with, or will be unable to comply with any effluent limitation specified in this permit, the permittee shall provide EPD with an oral report within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months from the time the permittee becomes aware of the circumstances followed by a written report within five (5) days of becoming aware of such condition. The written submission shall contain the following information:

a. A description of the discharge and cause of noncompliance; and

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

3. Facility Operation The permittee shall at all times maintain in good working order and operate as efficiently as possible all treatment or control facilities or systems installed or used by the permittee to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance includes effective performance, adequate funding, adequate operator staffing and training, and adequate laboratory and process controls, including appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems only when necessary to achieve compliance with the conditions of the permit.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 17 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

4. Adverse Impact The permittee shall take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment, including such accelerated or additional monitoring as necessary to determine the nature and impact of the noncomplying discharge.

5. Bypassing

a. If the permittee knows in advance of the need for a bypass, it shall submit prior notice to EPD at least 10 days (if possible) before the date of the bypass. The permittee shall submit notice of any unanticipated bypass with an oral report within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months from the time the permittee becomes aware of the circumstances followed by a written report within five (5) days of becoming aware of such condition. The written submission shall contain the following information:

1. A description of the discharge and cause of noncompliance; and

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

b. Any diversion or bypass of facilities covered by this permit is prohibited, except (i) where unavoidable to prevent loss of life, personal injury, or severe property damage; (ii) there were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime (this condition is not satisfied if the permittee could have installed adequate back-up equipment to prevent a bypass which occurred during normal periods of equipment downtime or preventive maintenance); and (iii) the permittee submitted a notice as required above. The permittee shall operate the treatment works, including the treatment plant and total sewer system, to minimize discharge of the pollutants listed in Part I of this permit from combined sewer overflows or bypasses. Upon written notification by EPD, the permittee may be required to submit a plan and schedule for reducing bypasses, overflows, and infiltration in the system.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 18 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

6. Sludge Disposal Requirements Sludge shall be disposed of in accordance with the regulations and guidelines established by EPD, the Federal Clean Water Act, and the Resource Conservation and Recovery Act (RCRA). Prior to disposal of sludge by any method other than co-disposal in a permitted sanitary landfill, the permittee shall submit a sludge management plan to the Watershed Protection Branch of EPD for written approval. For land application of nonhazardous sludge, the permittee shall comply with the applicable criteria outlined in the most current version of EPDs "Guidelines for Land Application of Sewage Sludge (Biosolids) at Agronomic Rates" and with the State Rules, Chapter 391-3-6-.17. EPD may require more stringent control of this activity. Prior to land applying nonhazardous sludge, the permittee shall submit a sludge management plan to EPD for review and approval. Upon approval, the plan for land application will become a part of the NPDES permit upon modification of the permit.

7. Sludge Monitoring Requirements The permittee shall develop and implement procedures to ensure adequate year-round sludge disposal. The permittee shall monitor the volume and concentration of solids removed from the plant. Records shall be maintained which document the quantity of solids removed from the plant. The ultimate disposal of solids shall be reported (in the unit of lbs) as specified in Part I.D of this permit.

8. Power Failures Upon the reduction, loss, or failure of the primary source of power to said water pollution control facilities, the permittee shall use an alternative source of power if available to reduce or otherwise control production and/or all discharges in order to maintain compliance with the effluent limitations and prohibitions of this permit.

If such alternative power source is not in existence, and no date for its implementation appears in Part I, the permittee shall halt, reduce or otherwise control production and/or all discharges from wastewater control facilities upon the reduction, loss, or failure of the primary source of power to said wastewater control facilities.

9. Operator Certification Requirements The permittee shall ensure that, when required, a certified operator is in charge of the facility in accordance with Georgia State Board of Examiners for Certification of Water and Wastewater Treatment Plant operators And Laboratory Analysts Rule 43-51-6.(b)

10. Laboratory Analyst Certification Requirements The permittee shall ensure that, when required, the person in responsible charge of the laboratory performing the analyses for determining permit compliance is certified in accordance with the Georgia Certification of Water and Wastewater Treatment Plant operators and Laboratory Analysts Act, as amended, and the Rules promulgated thereunder.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 19 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 B. Responsibilities

1. Right of Entry The permittee shall allow the Director of EPD, the Regional Administrator of EPA, and/or their authorized representatives, agents, or employees, upon the presentation of credentials:

a. To enter upon the permittee's premises where a discharge source is located or in which any records are required to be kept under the terms and conditions of this permit; and

b. At reasonable times, to have access to and copy any records required to be kept under the terms and conditions of this permit; to inspect any facilities, equipment (including monitoring and control equipment), practices, or operations regulated or required under this permit; and to sample any substance or parameters in any location.

2. Transfer of Ownership or Control A permit may be transferred to another person by a permittee if:

a. The permittee notifies the Director of EPD in writing of the proposed transfer at least thirty (30) days in advance of the proposed transfer;

b. A written agreement containing a specific date for transfer of permit responsibility and coverage between the current and new permittee (including acknowledgement that the existing permittee is liable for violations up to that date, and that the new permittee is liable for violations from that date on) is submitted to the Director at least thirty (30) days in advance of the proposed transfer; and

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

3. Availability of Reports Except for data deemed to be confidential under O.C.G.A. § 12-5-26 or by the Regional Administrator of the EPA under the Code of Federal Regulations, Title 40, Part 2, all reports prepared in accordance with the terms of this permit shall be available for public inspection at an office of EPD. Effluent data, permit applications, permittee's names and addresses, and permits shall not be considered confidential.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 20 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

4. Permit Modification This permit may be modified, suspended, revoked or reissued in whole or in part during its term for cause including, but not limited to, the following:

a. Violation of any conditions of this permit;

b. Obtaining this permit by misrepresentation or failure to disclose fully all relevant facts;

c. A change in any condition that requires either a temporary or permanent reduction or elimination of the permitted discharge; or

d. To comply with any applicable effluent limitation issued pursuant to the order of the United States District Court for the District of Columbia issued on June 8, 1976, in Natural Resources Defense Council, Inc. et.al. v. Russell E. Train, 8 ERC 2120(D.D.C. 1976), if the effluent limitation so issued:

1. is different in conditions or more stringent than any effluent limitation in the permit; or

2. controls any pollutant not limited in the permit.

5. Toxic Pollutants The permittee shall comply with effluent standards or prohibitions established pursuant to Section 307(a) of the Federal Clean Water Act for toxic pollutants, which are present in the discharge within the time provided in the regulations that establish these standards or prohibitions, even if the permit has not yet been modified to incorporate the requirement.

6. Civil and Criminal Liability Nothing in this permit shall be construed to relieve the permittee from civil or criminal penalties for noncompliance.

7. State Laws 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 regulation under authority preserved by Section 510 of the Federal Clean Water Act.

8. Water Quality Standards Nothing in this permit shall be construed to preclude the modification of any condition of this permit when it is determined that the effluent limitations specified herein fail to achieve the applicable State water quality standards.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 21 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

9. 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.

10. Expiration of Permit The permittee shall not discharge after the expiration date. In order to receive authorization to discharge beyond the expiration date, the permittee shall submit such information, forms, and fees as are required by EPD at least 180 days prior to the expiration date.

11. Contested Hearings Any person who is aggrieved or adversely affected by an action of the Director of EPD shall petition the Director for a hearing within thirty (30) days of notice of such action.

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

13. Best Management Practices The permittee will implement best management practices to control the discharge of hazardous and/or toxic materials from ancillary manufacturing activities. Such activities include, but are not limited to, materials storage, in-plant transfer, process and material handling, loading and unloading operations, plant site runoff, and sludge and waste disposal.

14. Need to Halt or Reduce Activity Not a Defense It shall not be a defense for a 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.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 22 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

15. Duty to Provide Information

a. The permittee shall furnish to the EPD 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 upon request copies of records required to be kept by this permit.

b. When the permittee becomes aware that it failed to submit any relevant facts in a permit application or submitted incorrect information in a permit application or any report to the Director, it shall promptly submit such facts and information.

16. Duty to Comply

a. The permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Georgia Water Quality Control Act (O.C.G.A. § 12-5-20 et. seq.) and is grounds for enforcement action; for permit termination; revocation and reissuance, or modification; or for denial of a permit renewal application. Any instances of noncompliance must be reported to EPD as specified in Part I. D and Part II.A. of this permit.

b. Penalties for violations of permit conditions. The Federal Clean Water Act and the Georgia Water Quality Control Act (O.C.G.A. § 12-5-20 et. seq.) provide that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required under this permit, makes any false statement, representation, or certification in any record or other document submitted or required to be maintained under this permit, including monitoring reports or reports of compliance or noncompliance shall, upon conviction be punished by a fine or by imprisonment, or by both. The Georgia Water Quality Control Act (Act) also provides procedures for imposing civil penalties which may be levied for violations of the Act, any permit condition or limitation established pursuant to the Act, or negligently or intentionally failing or refusing to comply with any final or emergency order of the Director.

17. Upset Provisions Provisions of 40 CFR 122.41(n)(1)-(4), regarding "Upset" shall be applicable to any civil, criminal, or administrative proceeding brought to enforce this permit.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 23 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 PART III A. Previous Permits

1. All previous State wastewater permits issued to this facility, whether for construction or operation, are hereby revoked by the issuance of this permit. This action is taken to assure compliance with the Georgia Water Quality Control Act, as amended, and the Federal Clean Water Act, as amended. Receipt of the permit constitutes notice of such action. The conditions, requirements, terms and provisions of this permit authorizing discharge under the National Pollutant Discharge Elimination System govern discharges from this facility.

B. Schedule of Compliance

1. The permittee shall achieve compliance with the effluent limitations specified for discharges in accordance with the following schedule: N/A

2. No later than 14 calendar days following a date identified in the above schedule of compliance, the permittee shall submit either a report of progress or, in the case of specific actions being required by identified dates, a written notice of compliance or noncompliance, any remedial actions taken, and the probability of meeting the next scheduled requirement.

C. Special Conditions

1. Total Residual Chlorine/Free Available Chlorine

a. Neither free available chlorine (FAC) nor total residual chlorine (TRC) may be discharged from any single generating unit for more than two hours in any one day and not more than one generating unit in any plant may discharge these materials at any one time unless the permittee can demonstrate to and get written authorization from the EPD Director that the units in a particular location cannot operate at or below this level of chlorination.

b. The free available chlorine (FAC) average and total residual chlorine (TRC) average means the average over any individual chlorine or oxidant release period which does not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months per day per generating unit. The FAC and TRC maximum is the instantaneous maximum which may occur at any time. The results shall be reported in a suitably concise form beginning with the first scheduled Discharge Monitoring Report & Operation Monitoring Report (OMR) and continuing thereafter.

c. If bromine or a combination of bromine and chlorine is utilized for control of biofouling, limitations for TRC and FAC shall be applicable to TRO (Total Residual Oxidants) and FAO (Free Available Oxidants). There is no difference in test methods between TRC/FAC and TRO/FAO.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 24 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

2. Annual Certifications The permittee shall certify annually that none of the 126 priority pollutants listed in Appendix A of 40 CFR 423, excluding chromium and zinc, are above detectable limits in internal outfall numbers 002 and 003. This certification may be based on manufacturers certifications or engineering calculations. Additionally, a certification that chromium and/or zinc are below detectable limits may be used in lieu of monitoring required in Part I.A.2 of the permit. Such certifications shall be submitted as part of the June OMR in accordance with Part I.D of the permit.

3. No Discharge of Polychlorinated Biphenyl Compounds There shall be no discharge of polychlorinated biphenyl compound such as those commonly used for transformer fluid.

4. No Detectable Level of Hydrazine No detectable level of Hydrazine is allowed in Outfall 001. This analysis shall be conducted and submitted annually in accordance with the reporting requirements in Part I.D of this permit and when requested by EPD.

5. Chemical Metal Cleaning Wastes

a. Any chemical metal cleaning wastes generated will be contained for further treatment or disposal in a manner to permit compliance at time of discharge with requirements listed below. This applies to any preoperational chemical cleaning of metal process equipment also.

b. The quantity of pollutants discharged in chemical metal cleaning waste shall not exceed the quality determined by multiplying the flow of metal cleaning wastes times the concentrations listed below. All effluent characteristics shall be monitored once (1) per week by grab sampling when a discharge is occurring from outfall nos. 004 and 005 when applicable. The results shall be reported on the OMR in accordance with the reporting requirements in Part I.D of this permit.

Discharge Limitation (mg/L)

Parameter Daily Average Daily Maximum Total Suspended Solids 30.0 100.0 Oil & Grease 15.0 20.0 Copper, Total 1.0 1.0 Iron, Total 1.0 1.0

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 25 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

6. §316(b) of the Clean Water Act (CWA) & Cooling Water Intake Structures

a. The permittee is subject to the Track I requirements applicable to cooling water intake structures for new facilities promulgated at 40 C.F.R. 125 - Subpart I. The permittee must operate a closed-cycle recirculating cooling water system and must design and construct each cooling water intake structure at the facility to a maximum through-screen design intake velocity of 0.5 ft/s and such that the total design intake flow from all cooling water intake structures at the facility is no greater than 5% of the source water annual mean flow.

b. The permittee must monitor both impingement and entrainment of the commercial, recreational, and forage base fish and shellfish species identified in the Source Water Baseline Biological Characterization data submitted with the application. The monitoring methods used must be consistent with those used for the Source Water Baseline Biological Characterization data. Biological monitoring shall become effective upon the commencement of commercial operations for Unit 3. Biological monitoring is required at the frequencies identified below for two (2) years following the commencement of commercial operations for Unit 3 and one (1) year following the commencement of commercial operations for Unit 4. After that time, the Director may approve a request for less frequent sampling, if the supporting data shows that less frequent monitoring would still allow for the detection of any seasonal and daily variations in the species and numbers of individuals that are impinged or entrained.

(i) The permittee must collect samples to monitor impingement rates (simple enumeration) for each species over a 24-hour period and no less than once per month when the cooling water intake structure is in operation.

(ii) The permittee must collect samples at least biweekly to monitor entrainment rates (simple enumeration) for each species over a 24-hour period during the primary period of reproduction, larval recruitment, and peak abundance identified during the Source Water Baseline Biological Characterization when the cooling water intake structure is in operation.

c. The permittee must conduct velocity monitoring upon commencement of commercial operation and thereafter, at a frequency of monthly. To conduct velocity monitoring, the permittee must monitor head loss across the screens and correlate the measured value with the design intake velocity. The head loss across the intake screen must be measured at the minimum ambient source water surface elevation (best professional judgement based on hydrological data). The maximum head loss across the screen for each cooling water intake structure must be used to determine compliance with the through-screen design intake velocity requirement in Part III.C.6.a of this permit.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 26 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

d. The permittee must monitor the intake flows at a minimum frequency of daily. The monitoring must include measuring cooling water withdrawals and blowdown volume. In lieu of daily intake flow monitoring the permittee may monitor the cycles of concentration at a minimum frequency of daily. Monitoring will be included in the OMR and submitted in accordance with Part I.D of the permit.

e. The permittee must either conduct visual inspections or employ remote monitoring devices on at least a quarterly basis during the period in which the cooling water intake structure is in operation. Such inspections must ensure that the cooling towers operated to comply with 40 CFR 125.84(b) (Track I requirements) are maintained and operated to function as designed. The permittee must prepare an inspection report documenting the inspections or monitoring and the inspection report shall be submitted as an attachment to the DMR in accordance with Part I.D of the permit.

The inspection report shall contain the following minimum elements:

(i) Date, time, and location of the inspection or remote monitoring; (ii) Water withdrawal rate during the time of inspection; (iii) Equipment/Technology identified as needing maintenance, repair or replacement, if any; and (iv) Name(s) and signature(s) of the inspector(s)

f. The permittee shall submit an annual status report signed by the responsible corporate officer as an attachment to the DMR due June 15th. The annual status report must include the following items:

(i) Biological monitoring records for each cooling water intake structure as required by Part III.C.6.b of this permit.

(ii) Velocity and head loss monitoring records for each cooling water intake structure as required by Part III.C.6.c of this permit.

(iii) Record of visual or remote inspections as required by Part III.C.6.e of this permit.

g. The permittee shall retain records of all submissions related to the permit application and conditions outlined in Part III.C.6 of this permit until the subsequent permit has been issued.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 27 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420

7. Thermal Mixing Zone & Temperature Modeling

a. The approved thermal mixing zone is defined as the segment of the river extending 81 feet downstream from the point of discharge with a width of 22 feet extending from the west riverbank. The downstream sampling location for compliance with the temperature requirement outline in Part I.A.1 of the permit is at the centerline of the downstream edge of the defined mixing zone at a depth of one (1) meter.

b. The permittee shall perform an instream temperature study in the vicinity of outfall number 001 to demonstrate the results of the CORMIX model within the first two years of commercial operation of Vogtle Unit 4 and while all four units (Vogtle Electric Generating Plants, Units 1-4) are operational. The study shall be conducted during the critical periods of the year, the summer months (August - October) and the winter months (December - February) for the maximum and delta T water quality standards.

(i) Prior to performing the temperature study, the permittee shall submit the proposed temperature study plan to EPD for review and approval. The study, at a minimum, shall include plans to monitor and report effluent temperature and instream monitoring locations at several transects within the receiving water.

(ii) If the field conditions do not exist within the first two years as referenced above (for example, low flows do not exist, the winter months are abnormally warm or other weather and/or field conditions prevent the permittee from performing the temperature study within the referenced timeframe) the permittee may submit a written request to EPD for an extension from the two-year deadline referenced above. EPD may review the request and make a determination ensuring the temperature study is performed during a representative time period to validate the results of the CORMIX modeling.

STATE OF GEORGIA DEPARTMENT OF NATURAL RESOURCES Page 28 of 28 ENVIRONMENTAL PROTECTION DIVISION Permit No. GA0039420 D. Biomonitoring and Toxicity Reduction Requirements

1. The permittee shall comply with effluent standards or prohibitions established by section 307(a) of the Federal Act and with chapter 391-3-6-.03(5)(e) of the State Rules and may not discharge toxic pollutants in concentrations or combinations that are harmful to humans, animals, or aquatic life.

If toxicity is suspected in the effluent, EPD may require the permittee to perform any of the following actions:

a. Acute biomonitoring tests;

b. Chronic biomonitoring tests;

c. Stream studies;

d. Priority pollutant analyses;

e. Toxicity reduction evaluations (TRE); or

f. Any other appropriate study.

2. EPD will specify the requirements and methodologies for performing any of these tests or studies. Unless other concentrations are specified by EPD, the critical concentration used to determine toxicity in biomonitoring tests will be the effluent instream wastewater concentration (IWC) based on the representative plant flow of the facility and the critical low flow of the receiving stream (7Q10). The endpoints that will be reported are the effluent concentration that is lethal to 50% of the test organisms (LC50) if the test is for acute toxicity, and the no observed effect concentration (NOEC) of effluent if the test is for chronic toxicity.

The permittee must eliminate effluent toxicity and supply EPD with data and evidence to confirm toxicity elimination.

ENYIRONMENTAL PRoTECTION DMSION The Georgia Environmental Protection Division proposes to issue an NPDES permit to the applicant identified below. The draft permit places conditions on the discharge of pollutants from the wastewater treatment plant to waters of the State.

Technical

Contact:

Ian McDowell (ian.mcdowell@dnr.ga.gov) 470-604-9483 Draft permit:

- First issuance Reissuance with no or minor modifications from previous permit Reissuance with substantial modifications from previous permit

Modification of existing permit Requires EPA review Designated as a major facility 1.0 FACILITY INFORMATION 1.1 NPDES Permit No.: GA0039420 1.2 Name and Address of Owner/Applicant Southern Nuclear Operating Company (Operator) 3535 Colonnade Parkway BIN N-218-EC Birmingham, Alabama 35243 1.3 Name and Address of Facility Vogtle Electric Generating Plant, Units 3 & 4 7821 River Road Waynesboro, Georgia 30830 (Burke County)

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 1

1.4 Location and Description of the discharge (as reported by applicant)

Receiving Outfall ID Latitude Longitude Waterbody 33° 08' 52.99" N 81° 45' 8.99" W 001 Savannah River (33.148055) (-81.752500) 33° 09' 16.99" N 81° 45' 31.99" W 011 Savannah River (33.154722) (-81.758888) 1.5 Production Capacity This permit covers Vogtle Electric Generating Plant, Units 3 & 4 which are rated at 1,200 MW per unit.

1.6 SIC Code & Description 4911 - Generation of Electricity 1.7 Description of Industrial Processes Vogtle Electric Generating Plant, Units 3 & 4 is jointly owned by Georgia Power Company, Oglethorpe Power Corporation, Municipal Electric Authority of Georgia, and the City of Dalton, Georgia with Southern Nuclear Operating Company being the operator. The facility generates electricity through the use of nuclear fuel.

1.8 Description of the Wastewater Treatment Facility Units 3 & 4 cooling tower blowdown and Units 3 & 4 service water system (SWS) cooling tower blowdown is periodically chlorinated for disinfection. During periods of chlorination, a dechlorination system typically runs at the blowdown sump. Units 3 & 4 SWS cooling tower blowdown is routed to the Units 3 & 4 cooling tower blowdown basins and commingles with the other blowdown wastestreams before discharging to the blowdown sump mixing box. Low volume wastewater from the facility is routed to two wastewater retention basins for settling treatment before discharging to the blowdown sump mixing box. Radwaste dilution flows may also be discharged to the blowdown sump mixing box, as needed. Discharges from the sump mixing box commingle with the low volume wastes that originate from the Units 3&4 liquid radwaste systems which have been treated via ion exchange treatment. All the discharges listed above combine and discharge to the Savannah River via Outfall 001. Intake screen backwash discharges via Outfall 011 and receives no treatment.

Outfall Operation Description Treatment Description 001 Final Plant Discharge Discharge to Surface Waters Unit 3 Cooling Tower Blowdown 002 Dechlorination Unit 3 SWS Cooling Tower Blowdown Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 2

Unit 4 Cooling Tower Blowdown 003 Dechlorination Unit 4 SWS Cooling Tower Blowdown Sedimentation (Settling),

004 Unit 3 Wastewater Retention Basin Dechlorination Sedimentation (Settling),

005 Unit 4 Wastewater Retention Basin Dechlorination Unit 3 Liquid Radwaste Systems 006 Ion Exchange Discharge Unit 4 Liquid Radwaste Systems 007 Ion Exchange Discharge 010 Radwaste Dilution Flow to Outfall None 011 Intake Screen Backwash Discharge to Surface Waters 1.9 Type of Wastewater Discharge process wastewater

stormwater domestic wastewater cg] combined other (radwaste dilution flow & intake screen backwash)

Cooling tower blowdown, low volume waste (including liquid radwaste), and radwaste dilution flow (if necessary) commingle and discharge via Outfall 001. Discharges from Outfall 011 consist solely of intake screen backwash.

1.10 Characterization of Effluent Discharge as Reported by Applicant (Form 2C,Section V, Part A only. Please refer to the application for additional analysis) 1.10.1 Outfall No. 001 - Final Plant Discharge Effluent Characteristics Maximum Average (as Reported by Applicant) Daily Value Daily Value Flow (MGD) 63 11 Biochemical Oxygen Demand,5-day 3.69 N/A (mg/L)

Total Suspended Solids (mg/L) 9 N/A Temperature, Winter (°F) 53.6 N/A Temperature, Summer (°F) 87.8 N/A Ammonia (mg/L) <0.10 N/A Total Phosphorus (mg/L) 1.38 N/A Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 3

1.10.2 Outfall No. 011 - Intake Screen Backwash Effluent Characteristics Maximum Average (as Reported by Applicant) Daily Value Daily Value Flow (MGD) 1.8 1.7 Biochemical Oxygen Demand,5-day

<2.0 N/A (mg/L)

Total Suspended Solids (mg/L) 25 N/A Temperature, Winter (°F) 48.0 N/A Temperature, Summer (°F) 86.4 N/A Ammonia (mg/L) <0.10 N/A Total Phosphorus (mg/L) Not Provided N/A 2.0 APPLICABLE REGULATIONS 2.1 State Regulations Chapter 391-3-6 of the Georgia Rules and Regulations for Water Quality Control 2.2 Federal Regulations Source Activity Applicable Regulation 40 CFR 122 Non-Process Water 40 CFR 125 Discharges 40 CFR 127 40 CFR 136 40 CFR 122 Industrial (Non POTW) 40 CFR 125 Process Water Discharges 40 CFR 127 40 CFR 136 40 CFR 423 CWA 316(b) Cooling 40 CFR 122 Water Intake Structures 40 CFR 125 2.3 Industrial Effluent Limit Guideline(s)

Code of Federal Regulations, 40 CFR Part 423 - Steam Electric Power Generating Point Source Category See Appendix A of the Fact Sheet for a copy of the 40 CFR Part 423 - Steam Electric Power Generating Source Category regulations.

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 4

3.0 WATER QUALITY STANDARDS & RECEIVING WATERBODY INFORMATION Section 301(b)(1)(C) of the Clean Water Act (CWA) requires the development of limitations in permits necessary to meet water quality standards. Federal Regulations 40 CFR 122.4(d) require that conditions in NPDES permits ensure compliance with the water quality standards which are composed of use classifications, numeric and or narrative water quality criteria and an antidegradation policy. The use classification system designates the beneficial uses that each waterbody is expected to achieve, such as drinking water, fishing, or recreation. The numeric and narrative water quality criteria are deemed necessary to support the beneficial use classification for each water body. The antidegradation policy represents an approach to maintain and to protect various levels of water quality and uses.

3.1 Receiving Waterbody Classification and Information Designated Water Use: The designated water use for the Savannah River is fishing.

[391-3-6-.03(6)]

Fishing:

Propagation of Fish, Shellfish, Game and Other Aquatic Life; secondary contact recreation in and on the water; or for any other use requiring water of a lower quality.

(i) Dissolved Oxygen: A daily average of 6.0 mg/L and no less than 5.0 mg/L at all times for water designated as trout streams by the Wildlife Resources Division. A daily average of 5.0 mg/L and no less than 4.0 mg/L at all times for waters supporting warm water species of fish.

(ii) pH: Within the range of 6.0 - 8.5.

(iii) Bacteria:

1. For the months of May through October, when water contact recreation activities are expected to occur, fecal coliform not to exceed a geometric mean of 200 per 100 mL based on at least four samples collected from a given sampling site over a 30-day period at intervals not less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Should water quality and sanitary studies show fecal coliform levels from non-human sources exceed 200/100 mL (geometric mean) occasionally, then the allowable geometric mean fecal coliform shall not exceed 300 per 100 mL in lakes and reservoirs and 500 per 100 mL in free flowing freshwater streams. For the months of November through April, fecal coliform not to exceed a geometric mean of 1,000 per 100 mL based on at least four samples collected from a given sampling site over a 30-day period at intervals not less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and not to exceed a maximum of 4,000 per 100 mL for any sample. The State does not encourage swimming in these surface waters since a number of factors which are beyond the control of Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 5

any State regulatory agency contribute to elevated levels of bacteria.

2. For waters designated as shellfish growing areas by the Georgia DNR Coastal Resources Division, the requirements will be consistent with those established by the State and Federal agencies responsible for the National Shellfish Sanitation Program. The requirements are found in National Shellfish Sanitation Program Guide for the Control of Molluscan Shellfish, 2007 Revision (or most recent version), Interstate Shellfish Sanitation Conference, U.S. Food and Drug Administration.

(iv) Temperature: Not to exceed 90°F. At no time is the temperature of the receiving waters to be increased more than 5°F above intake temperature except that in estuarine waters the increase will not be more than 1.5°F. In streams designated as primary trout or smallmouth bass waters by the Wildlife Resources Division, there shall be no elevation of natural stream temperatures. In streams designated as secondary trout waters, there shall be no elevation exceeding 2°F natural stream temperatures.

3.2 Ambient Information Hardness Annual Upstream Total Outfall 7Q10 1Q10 (mg/L as Average Flow Suspended Solids ID (cfs) (cfs)

CaCO3) (cfs) (mg/L) 001 3900 3700 14 9500 9 011 3900 3700 14 9500 9 3.3 Georgia 305(b)/303(d) List Documents Savannah River (McBean Creek to Johnsons Landing) is listed as supporting the designated use in the 2020 305(b)/303(d) Integrated Report. While this Savannah River Reach is listed as supporting its designated use, it is within the scope of the Category 5R Restoration Plan for the Savannah Harbor which is discussed in Section 3.5.

R"ach Name/ID Reach Location/County River Basin/ Assessment/ cause/ Size/Unit Category/ Notes use Data Provider source Priority IMcESean Creek 10 1140 111 J IS.avannah River 1savannah ohn.son.s Landing l~u pponlng II I IGAR030601060903 1surice, Screven !Fishing 111,10 II IIMllos II I t 3.4 Total Maximum Daily Load (TMDL)

There are no TMDLs which have been developed for this stream segment Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 6

3.5 Category 5R Alternative Restoration Plan In 2006 EPA established a TMDL for Savannah Harbor from SR 25 (old US Hwy 17) to Elba Island Cut. This segment, R030601090318 (HUC12:03061090307), was identified as impaired for dissolved oxygen (DO) based on its failure to meet the State of Georgias designated use of Coastal Fishing. The 2006 TMDL has since been superseded following the 2010 revision of Georgias DO water quality criterion and the subsequent approval of the Subcategory 5R Documentation For Point Source Dissolved Oxygen Impaired Water in the Savannah River Basin; hereafter 5R Plan. Development of the documentation behind the 5R Plan was a result of extensive collaboration between the Georgia Environmental Protection Division (GA EPD), the South Carolina Department of Health and Environmental Control (SC DHEC), the Environmental Protection Agency (EPA), a Technical Modeling Advisory Group, and the Savannah River/Harbor Dischargers Group.

The portions of the Savannah River Basin included in the 5R Plan are the middle and lower watersheds encompassing the area from Thurmond Dam to the Atlantic Ocean. The hydrodynamic and water quality models used to analyze the oxygen-demanding pollutant loadings extend upstream on the Savannah River to River Mile 61.0 near Clyo, Georgia, at United States Geologic Survey (USGS) station 02198500. The downstream end of the models extends approximately 25 miles offshore from Oyster Island to cover the navigational channel of Savannah Harbor. The models cover the Savannah River, the Front River, the Middle River, the Little Back River, the Back River, the South Channel, and the offshore portions in the Atlantic Ocean.

The process of developing this 5R Plan for the Savannah Harbor included developing three computer modeling tools: (1) the Savannah River Model, (2) the Savannah Harbor Model, and (3) the Savannah River and Harbor DO Calculator. Georgia EPD developed the Savannah River Model for the Savannah River from the Augusta Canal diversion dam to the USGS gaging station (02198760) above Hardeeville, South Carolina. The Savannah River Model used for this 5R Plan is the hydrodynamic and water quality model developed using GA RIV-1 for the 2006 TMDL. The Savannah River Model includes all major point sources to the River and simulates the effects municipal and industrial discharges have on both water quality and flow and was calibrated to available data. The output of the Savannah River Model is later used as the input for the Savannah Harbor Model. The Savannah Harbor Model used for the 5R Plan was built upon the Enhanced USACE Model that was finalized on January 30, 2006 and the 2006 Harbor TMDL Model developed by EPA Region 4 (Tetra Tech 2004, Tetra Tech 2006, EPA 2010). Combined, the Savannah River and Harbor models were used to develop the Savannah River and Harbor DO Calculator.

The Savannah River and Harbor DO Calculator was developed as an efficient method to calculate the effect various combinations of wastewater effluent dischargers have on the DO levels in the Savannah River and Harbor. In order to run the calculator, the 5R Plan identified 24 permitted facilities that discharge oxygen-demanding substances. Of these 24 facilities, eleven are considered to discharge to the harbor and thirteen are considered to discharge to the river. Using the calculator, wasteload allocations were developed for the 24 dischargers to establish limits for Ultimate Oxygen Demand (UOD) during the critical months of March

- October.

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Information pertaining to the technical basis for determining the load reductions for each wastewater discharger is discussed in Appendix B [of the 5R Plan]. The Memorandum of Understanding between the dischargers to the Savannah River and Harbor is included in Appendix C [of the 5R Plan], which reflects the consensus of the dischargers to the following allocations. The Appendix C [of the 5R Plan] waste load allocations will be used for the issuance of permits by Georgia and South Carolina for the included dischargers but it is not otherwise a final legal agreement by either state of the waste load allocation utilized proportionally by Georgia and South Carolina and agreement to this document does not waive any rights, ownership, or claims by either state to a different share of the waste load allocation. Appendix D contains the final Savannah River and Harbor DO Calculator Version 4.0 run.

Vogtle Electric Generating Plant, Units 3 & 4 is not identified in the 5R as one of the 24 point-source permitted facilities discharging oxygen demanding substances to the Savannah River/Harbor. Instead, as a matter of practice, EPA has established, acknowledged, and approved de minimis thresholds below which dischargers are not subject to specific wasteload allocations or reduction expectations. Any new or existing discharger that can demonstrate that its loading is within natural background at the point where their discharge meets the main stem of the Savannah River or Harbor shall be considered a background source. For purposes of this 5R Plan, background includes those dischargers whose impact on the delta DO deficit is of such an inconsequential nature that such discharges may be deemed part of the background load. After receipt and review of Southern Nuclear Companys Vogtle Electric Generating Plant, Units 3 & 4 NPDES application and an evaluation of the wastewater characteristics, EPD has determined that the facility is not a significant contributor of oxygen-demanding substances and falls within the de minimis threshold. No effluent limits or monitoring for UOD have been included in the permit.

Although Vogtle Electric Generating Plant is not a contributor of oxygen-demanding substances, there were concerns that the approval of the construction of Units 3&4 and the subsequent surface withdrawal for cooling water would stress the already impaired Savannah River system. To address the concern, the EPD included a requirement for the installation of an oxygen injection system in the Savannah Harbor as part of the Surface Water Withdrawal Permit for Vogtle Units 3&4. The effects of the dissolved oxygen injection were considered in the Savannah 5R modeling.

The Savannah Harbor has been the subject of extensive study, including extensive data collection, and model development by various state and federal agencies. The modeling analysis used to develop the effluent limits for the point source discharges to the Savannah River and Harbor were based upon an abundance of data, a calibrated and verified three dimensional model, and conservative critical condition and permitting assumptions. For these reasons, based on the data and information available, once the effluent limitations and special conditions contained in all discharge permits for facilities in the Savannah River Basin are achieved, the discharge will not cause or contribute to exceedances of the Georgia and South Carolina water quality standards for dissolved oxygen. However, if it is determined that a dissolved oxygen deficit exits in the Savannah Harbor that contravenes the Georgia or South Carolina water quality standards for dissolved oxygen and is attributable Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 8

to point source dischargers, then the regulatory agencies will work with all responsible parties to evaluate and implement viable options that will be incorporated into an updated 5R adaptive management plan and appropriate permits to ensure full attainment of the water quality standards.

The Savannah River and Harbor models account for the existing loads from the tributary wastewater dischargers as part of the background pollutant load to the Savannah River and Harbor. Future expansions and introduction of new facilities in tributaries that discharge to the Savannah River will have to meet a performance standard of demonstrating that their discharge is equal to the Savannah River background UOD concentration at the point of entry to the mainstem of the Savannah River.

3.6 Wasteload Allocation Date (06/26/2020)

See Appendix B of the Fact Sheet 4.0 PERMIT CONDITIONS AND EFFLUENT LIMITATIONS 4.1 Water Quality Based Effluent Limitations (WQBELs) & Technology Based Effluent Limitations (TBELs)

When drafting a National Pollutant Discharge Elimination System (NPDES) permit, a permit writer must consider the impact of the proposed pollutants in a discharge on the quality of the receiving water. Water quality goals for a waterbody are defined by state water quality criteria or standards. By analyzing the effect of a pollutant in the discharge on the receiving water, a permit writer could find that technology-based effluent limitations (TBELs) alone will not achieve the applicable water quality standards or protect downstream users. In such cases, the Clean Water Act (CWA) and its implementing regulations require development of water quality-based effluent limitations (WQBELs). WQBELs help meet the CWA objective of restoring and maintaining the chemical, physical, and biological integrity of the nations waters and the goal of water quality that provides for the protection and propagation of fish, shellfish, and wildlife and recreation in and on the water (fishable/swimmable).

WQBELs are designed to protect water quality by ensuring water quality standards are met in the receiving water and the designated use and downstream uses are protected. On the basis of the requirements of 40 C.F.R §125.3(a), additional or more stringent effluent limitations and conditions, such as WQBELs, are imposed when TBELs are not sufficient to protect water quality.

TBELs aim to prevent pollution by requiring a minimum level of effluent quality that is attainable using demonstrated technologies for reducing discharges of pollutants or pollution into the waters of the State. TBELs are developed independently of the potential impact of a discharge on the receiving water, which is addressed through water quality standards and WQBELs. The NPDES regulations at 40 C.F.R. §125.3(a) require NPDES permit writers to develop technology-based treatment requirements, consistent with CWA section 301(b), that represent the minimum level of control that must be imposed in a permit. The regulation also Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 9

requires permit writers to include in permits additional or more stringent effluent limitations and conditions, including those necessary to protect water quality.

For pollutants not specifically regulated by Federal Effluent Limit Guidelines (ELGS), the permit writer must identify any needed TBELS and utilize best professional judgment to establish TBELS or determine other appropriate means to control its discharge if there is a reasonable potential to cause or contribute to a violation of the water quality standards.

4.2 Reasonable Potential Analysis (RPA)

EPA regulations at 40 C.F.R. §122.44(d)(1)(i) state, Limitations must control all pollutants or pollutant parameters (either conventional, nonconventional, or toxic pollutants) which the Director determines are or may be discharged at a level that will cause, have the reasonable potential to cause, or contribute to an excursion above any [s]tate water quality standard, including [s]tate narrative criteria for water quality. [emphasis added]

EPA regulations at 40 C.F.R. §122.44(d)(1)(ii) require States to develop procedures for determining whether a discharge causes, has the reasonable potential to cause, or contributes to an instream excursion above a narrative or numeric criterion within a state water. If such reasonable potential is determined to exist, the NPDES permit must contain pollutant effluent limits and/or effluent limits for whole effluent toxicity. Georgia has reasonable potential procedures, based upon the specific category of pollutants and/or specific pollutant of concern. Chemical specific and biomonitoring data and other pertinent information in EPDs files will be considered in accordance with the review procedures specified in the GA Rules and Regulations for Water Quality Control, Chapter 391-3-6 in the evaluation of a permit application and in the evaluation of the reasonable potential for a discharge to cause an exceedance in the numeric or narrative criteria.

The term pollutant is defined in CWA section 502(6) and 40 C.F.R. §122.2. Pollutants are grouped into three categories under the NPDES program: conventional, toxic, and nonconventional. Conventional pollutants are those defined in CWA section 304(a)(4) and 40 C.F.R.§401.16 (five day-biochemical oxygen demand (BOD5), total suspended solids (TSS), fecal coliform, pH, and oil and grease). Toxic (priority) pollutants are those defined in CWA section 307(a)(1) and include 126 metals and manmade organic compounds.

Nonconventional pollutants are those that do not fall under either of the above categories (conventional or toxic pollutants) and include parameters such as, but not limited to, chlorine, ammonia, nitrogen, phosphorus, chemical oxygen demand (COD), and whole effluent toxicity (WET).

EPD evaluates the data provided in the application and supporting documents. If a pollutant is listed in the following sections of this fact sheet below, the permit writer determined the pollutant is a pollutant of concern and there may be a reasonable potential to cause or contribute to an instream violation of the Georgia water quality standards. If a pollutant is not listed below, EPD determined the pollutant is not a pollutant of concern or has determined, based on the data provided in the application, there is no reasonable potential to cause or contribute to an instream violation of the Georgia water quality standards. An example may be if the applicant reported not detect or below detection limit.

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Upon identification of a pollutant of concern by the permit writer, in accordance with 40 C.F.R. §122.44(d)(1)(ii), the permit writer must then perform a reasonable potential analysis using a procedure which has accounted for any combination of the following criteria:

existing controls on point and nonpoint sources of pollution, the variability of the pollutant or pollutant parameter in the effluent, the sensitivity of the species to toxicity testing (when evaluating whole effluent toxicity), and where appropriate, the dilution of the effluent in the receiving water to determine if the pollutant and its discharge has the reasonable potential to cause, or contribute to an in-stream excursion above the allowable ambient concentration of a state narrative or numeric criteria within the states water quality standard for an individual pollutant.

In accordance with 40 C.F.R. §122.44(d)(1)(iii), if the permit writer has determined, using a reasonable potential procedure the pollutant of concern in the discharge causes, has the reasonable potential to cause, or contributes to an in-stream excursion above the allowable ambient concentration of a state numeric or narrative criteria within a state water quality standard for an individual pollutant, the permit must contain effluent limits for that pollutant.

If the permit writer has determined there is insufficient data, the permit writer might also consider monitoring requirements to collect the additional data related to the presence or absence of a specific pollutant to provide information for further analyses for the development of appropriate numeric or narrative standard .

The conventional, nonconventional, and toxic pollutants listed in the following sections have been identified by the permit writer as pollutants of concern and the permit writer has determined through current practices and procedures one of the following: no additional monitoring or numeric and/or narrative effluent limits are needed; additional monitoring is required; or numeric and/or narrative effluent limits are necessary to protect the receiving water body and its downstream users and those limits have been included in the permit.

The monitoring and sampling locations are prescribed in the permit and determined by the permit writer after considering, at a minimum, the following: type of discharge, specific pollutant, discharge frequency, location of the discharge, receiving waterbody, downstream users, etc.

The sample type, grab vs. composite, is prescribed in the permit and determined by the permit writer after considering, at a minimum, the analytical method required in 40 C.F.R. §136, the type of pollutant, retention time, etc. Grab samples are required for the analysis of pH, temperature, cyanide, total phenols, residual chlorine, oil and grease, fecal coliform (including E. coli), or volatile organics.

4.3 Whole Effluent Toxicity The permittee shall comply with effluent standards or prohibitions established by section 307(a) of the Federal Act and with chapter 391-3-6-.03(5)(e) of the State Rules and may not discharge toxic pollutants in concentrations or combinations that are harmful to humans, animals, or aquatic life.

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If toxicity is suspected in the effluent, EPD may require the permittee to perform acute or chronic whole effluent toxicity testing.

Vogtle Electric Generating Plant, Units 3 & 4 are not yet operational, thus WET testing could not be performed on the discharge. WET testing was performed on the effluent for Vogtle Electric Generating Plant, Units 1 & 2 in January of 2018. Based on similarities in the wastestreams, water treatment chemicals, and expected discharge characteristics, this WET test is considered representative of the discharge from Vogtle Electric Generating Plant, Units 3 & 4.

Chronic WET testing was conducted from January 29, 2018 - February 4, 2018. Tests were run for Ceriodaphnia dubia and Pimephales promelas.

Results of the aquatic biomonitoring tests indicated no statistically significant effect on survival for C. dubia at up to 12.5% or survival and growth or reproduction for P. promelas at up to 100% effluent concentration (i.e., NOEC > IWC). No toxic effects were detected.

In accordance with EPDs Whole Effluent Toxicity (WET) Strategy (2001), chronic WET testing will be required at Outfall 001 once during the permit term with an additional WET test required to be submitted with the application.

4.4 Conventional Pollutants Pollutants of Outfall ID Basis Concern WQBEL pH 001 The instream waste concentration is 2.44%. When the instream waste concentration is less than 50%, there is no reasonable potential to cause or contribute to violation of the instream Georgia Water Quality Standard; therefore, a limit of 6.0 s.u.

to 9.0 s.u. has been added.

TBEL A pH effluent limit of 6.0 s.u. - 9.0 s.u. is required in accordance with 40 CFR 423.15(a)(1) New Source Performance Standards (NSPS).

WQBEL 011 Outfall 011 is limited to intake screen backwash from the cooling water intake structure. No chemical alterations occur which would affect the pH of the intake water; therefore, there is no reasonable potential to cause or contribute to a violation of the instream Georgia Water Quality Standard for pH. No limits or monitoring has been included in the permit.

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TBEL There is no applicable federal technology based effluent limit.

WQBEL 5-Day 001 EPD has reviewed the Plant Vogtle application and has Carbonaceous determined that the facility is a de minimis contributor of Biochemical oxygen demanding substances. Seasonal monitoring for the Oxygen months of March through October has been included in this Demand permit to ensure that the facilitys contribution of oxygen-demanding substances remains de minimis. See Section 3.5 for a full discussion of the 5R Plan and wasteload allocations for the Savannah River Basin.

TBEL There is no applicable federal technology based effluent limit.

WQBEL Total 001 Georgia has a narrative Water Quality Standard for total Suspended suspended solids. A narrative permit condition stating, there Solids shall be no floating solids, oil, scum or visible foam other than in trace amounts has been added.

TBEL The final outfall is commingled with several different wastestreams and when applicable, limits have been applied at internal outfalls for individual wastestreams prior to commingling.

WQBEL 004, 005, Georgia does not have Water Quality Standards for internal 006, 007 outfalls.

TBEL A daily average of 30.0 mg/L daily average and a daily maximum of 100.0 mg/L has been included in the permit in accordance with 40 CFR 423.15(a)(3) New Source Performance Standards (NSPS) for low volume waste.

WQBEL 011 Georgia has a narrative Water Quality Standard for total suspended solids. A narrative permit condition stating, there shall be no floating solids, oil, scum or visible foam other than in trace amounts has been added.

TBEL There is no applicable federal technology based effluent limit.

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WQBEL Oil & Grease 001 Georgia has a narrative Water Quality Standard for total suspended solids. A narrative permit condition stating, there shall be no floating solids, oil, scum or visible foam other than in trace amounts has been added.

TBEL The final outfall is commingled with several different wastestreams and when applicable, limits have been applied at internal outfalls for individual wastestreams prior to commingling.

WQBEL 004, 005, Georgia does not have Water Quality Standards for internal 006, 007 outfalls.

TBEL A daily average of 15.0 mg/L daily average and a daily maximum of 20.0 mg/L has been included in the permit in accordance with 40 CFR 423.15(a)(3) New Source Performance Standards (NSPS) for low volume waste.

WQBEL 011 Georgia has a narrative Water Quality Standard for total suspended solids. A narrative permit condition stating, there shall be no floating solids, oil, scum or visible foam other than in trace amounts has been added.

TBEL There is no applicable federal technology based effluent limit.

4.5 Nonconventional Pollutants Pollutants of Outfall ID Basis Concern WQBEL Temperature 001 Georgia has numeric Water Quality Criteria of 90 for Maximum and maximum temperature and a +5 temperature differential Temperature for freshwater waters (Ga. Comp. R. & Regs. 391-3 Differential .03(6)(a)(v)). EPD has granted a mixing zone for temperature that is defined as the segment of the river extending 81 feet downstream of the discharge, and extending 22 feet from the west bank of the river in accordance with Ga. Comp. R. &

Regs. 391-3-6-.03(10). See Section 5.4 for further discussion on the mixing zone.

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An effluent limitation of +5 will be applied at the edge of the mixing zone for the instream delta temperature. Thermal modeling showed compliance with the maximum temperature water quality standard required a much smaller mixing zone of 2.2 feet x 3.0 feet. As such, there is no reasonable potential for the discharge to cause or contribute to a violation of the maximum temperature water quality standard temperature at the downstream edge of the 81 foot mixing zone which is necessary for the temperature differential water quality standard. Thus, monitoring only has been included for the maximum temperature.

TBEL There is no applicable federal technology based effluent limit.

WQBEL Total Residual 002, 003 Georgia does not have Water Quality Standards for internal Chlorine outfalls.

TBEL Monitoring has been included in the permit for total residual chlorine in order to ensure compliance with the FAC/TRC discharge limitations in 40 CFR 423.15(a)(10)(ii) New Source Performance Standards (NSPS) for cooling tower blowdown.

WQBEL Free Available 002, 003 Georgia does not have Water Quality Standards for internal Chlorine outfalls.

TBEL A daily average of 0.2 mg/L and a daily maximum of 0.5 mg/L has been included in the permit in accordance with 40 CFR 423.15(a)(10)(i) New Source Performance Standards (NSPS) for cooling tower blowdown.

WQBEL FAC/TRC 002, 003 Georgia does not have Water Quality Standards for internal Discharge Time outfalls.

TBEL In accordance with 40 CFR 423.15(a)(10)(ii) New Source Performance Standards (NSPS) for cooling tower blowdown, 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 generating unit Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 15

at any plant may discharge free available or total residual chlorine at any one time.

See Special Conditions at Section 5.2.1 for limitations to FAC/TRC Discharge Time.

WQBEL Ammonia, 001, 011 Ammonia was non-detect in the discharge from outfalls 001 Organic and 011. Per the NPDES Permitting Strategy for Addressing Nitrogen, Total Ammonia Toxicity (2017), ammonia will not be considered Kjeldahl present at levels of concern and EPD will not include a numeric Nitrogen, effluent limit or monitoring requirement for ammonia. In Nitrate/Nitrite, addition, no effluent limitation or monitoring has been included as N for the following nitrogen containing constituents: organic nitrogen, total Kjeldahl nitrogen, and nitrate-nitrite.

TBEL There is no applicable federal technology based effluent limit.

WQBEL Total 001 Per the Strategy for Addressing Phosphorus in NPDES Phosphorus Permitting (2011) all routine permit reissuances must include phosphorus monitoring.

TBEL There is no applicable federal technology based effluent limit.

4.6 Toxics & Manmade Organic Compounds (126 priority pollutants and metals)

Pollutants of Outfall ID Basis Concern WQBEL Chromium, 002, 003 Georgia does not have Water Quality Standards for internal Total outfalls.

TBEL A daily average of 0.2 mg/L and a daily maximum of 0.2 mg/L has been included in the permit in accordance with 40 CFR 423.15(a)(10)(i) New Source Performance Standards (NSPS) for cooling tower blowdown.

WQBEL Zinc, Total 002, 003 Georgia does not have Water Quality Standards for internal outfalls.

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TBEL A daily average of 1.0 mg/L and a daily maximum of 1.0 mg/L has been included in the permit in accordance with 40 CFR 423.15(a)(10)(i) New Source Performance Standards (NSPS) for cooling tower blowdown.

WQBEL 126 Priority 002, 003 Georgia does not have Water Quality Standards for internal Pollutants outfalls.

TBEL In accordance with 423.15(a)(10)(i) New Source Performance Standards (NSPS) for cooling tower blowdown, all 126 priority pollutants contained in chemicals added for cooling tower maintenance; except chromium, total and zinc, total shall be non-detectable.

4.7 Calculations for Water Quality Based Effluent Limits 4.7.1 Instream Waste Concentration (IWC)

Outfall 001 IWC = Effluent Flow (gal/day)

Effluent Flow (gal/day) + 7Q10 (gal/day)

IWC = 63,000,000 (gal/day)

(63,000,000 (gal/day) + 2,520,460,800 (gal/day))

IWC = 0.0244 or 2.44%

Outfall 011 IWC = Effluent Flow (gal/day)

Effluent Flow (gal/day) + 7Q10 (gal/day)

IWC = 1,800,000 (gal/day)

(1,800,000 (gal/day) + 2,520,460,800 (gal/day))

IWC = 0.0007 or 0.07%

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4.8 Technology Based Effluent Limitation Calculations There are several ways to calculate TBELs when developing case-by-case limitations. EPD can use an approach consistent with the statistical approach EPA has used to develop effluent guidelines or they can utilize several other mathematically and statistically accepted approaches depending on characteristics of the data. In general, EPD utilizes EPAs NPDES Permit Writer Manual, September 2010, Section 5.2.3, Case-by-Case TBELs for Industrial Dischargers and EPAs Technical Support Document for Water Quality Based Toxic Control, March 1991, Section 5.2, Basis Principles of Effluent Variability, as guidance to develop limits.

If applicable, when there is no federal technology based effluent limit EPD evaluates the effluent data, operating records and discharge monitoring reports to calculate the long-term average for the parameter. The long-term average is then used to derive the effluent limits.

EPD recognizes there are several ways to calculate technology-based limits and, when applicable, may deviate from the general practice.

4.9 Comparison & Summary of Water Quality vs. Technology Based Effluent Limits After preparing and evaluating applicable technology-based effluent limitations and water quality-based effluent limitations, the most stringent limits are applied in the permit.

Pollutants of concern with an effluent limit of monitor and report are not included in the below table.

4.9.1 External Outfall 001 Parameter WQBELs TBELs Explanation pH (s.u.) 6.0 - 9.0 6.0 - 9.0 WQBEL - WQS Delta Temperature () +5 None WQBEL - WQS 4.9.2 Internal Outfalls 002 and 003 Parameter WQBELs TBELs Explanation Free Available N/A 0.2/0.5 TBEL - ELG Chlorine (mg/L)

FAC/TRC Discharge Time1 N/A 120 TBEL - ELG (minutes/day/unit)

Chromium, Total N/A 0.2/0.2 TBEL - ELG (mg/L)

Zinc, Total (mg/L) N/A 1.0/1.0 TBEL - ELG Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 18

1 The effluent limitation for FAC/TRC discharge time is expressed as a special condition and is the sum of the discharge time per generating unit (Unit 3 - Cooling Tower Blowdown / Service Water System Cooling Tower Blowdown; Unit 4 - Cooling Tower Blowdown / Service Water System Cooling Tower Blowdown.

4.9.3 Internal Outfalls 004 and 005 Parameter WQBELs TBELs Explanation Total Suspended Solids N/A 30.0/100.0 TBEL - ELG (mg/L)

Oil and Grease (mg/L) N/A 15.0/20.0 TBEL - ELG 4.9.4 Internal Outfalls 006 and 007 Parameter WQBELs TBELs Explanation Total Suspended Solids N/A 30.0/100.0 TBEL - ELG (mg/L)

Oil and Grease (mg/L) N/A 15.0/20.0 TBEL - ELG 5.0 OTHER PERMIT REQUIREMENTS AND CONSIDERATIONS 5.1 Special Conditions 5.1.1 Total Residual Chlorine/Free Available Chlorine

a. Neither free available chlorine (FAC) nor total residual chlorine (TRC) may be discharged from any single generating unit for more than two hours in any one day and not more than one generating unit in any plant may discharge these materials at any one time unless the permittee can demonstrate to and get written authorization from the EPD Director that the units in a particular location cannot operate at or below this level of chlorination.

b. The free available chlorine (FAC) average and total residual chlorine (TRC) average means the average over any individual chlorine or oxidant release period which does not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months per day per generating unit. The FAC and TRC maximum is the instantaneous maximum which may occur at any time. The results shall be reported in a suitably concise form beginning with the first scheduled Discharge Monitoring Report & Operation Monitoring Report (OMR) and continuing thereafter.

c. If bromine or a combination of bromine and chlorine is utilized for control of biofouling, limitations for TRC and FAC shall be applicable to TRO (Total Residual Oxidants) and FAO (Free Available Oxidants). There is no difference in test methods between TRC/FAC and TRO/FAO.

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 19

5.1.2 Annual Certifications The permittee shall certify annually that none of the 126 priority pollutants listed in Appendix A of 40 CFR 423, excluding chromium and zinc, are above detectable limits in internal outfall numbers 002 and 003. This certification may be based on manufacturers certifications or engineering calculations. Additionally, a certification that chromium and/or zinc are below detectable limits may be used in lieu of monitoring required in Part I.A.2 of the permit. Such certifications shall be submitted as part of the June OMR in accordance with Part I.D of the permit.

5.1.3 No Discharge of Polychlorinated Biphenyl Compounds There shall be no discharge of polychlorinated biphenyl compound such as those commonly used for transformer fluid.

5.1.4 No Detectable Level of Hydrazine No detectable level of Hydrazine is allowed in Outfall 001. This analysis shall be conducted and submitted annually in accordance with the reporting requirements in Part I.D of this permit and when requested by EPD.

5.1.5 Chemical Metal Cleaning Wastes

a. Any chemical metal cleaning wastes generated will be contained for further treatment or disposal in a manner to permit compliance at time of discharge with requirements listed below. This applies to any preoperational chemical cleaning of metal process equipment also.

b. The quantity of pollutants discharged in chemical metal cleaning waste shall not exceed the quality determined by multiplying the flow of metal cleaning wastes times the concentrations listed below. All effluent characteristics shall be monitored once (1) per week by grab sampling when a discharge is occurring from outfall nos. 004 and 005 when applicable. The results shall be reported on the OMR in accordance with the reporting requirements in Part I.D of this permit.

Discharge Limitation (mg/L)

Parameter Daily Average Daily Maximum Total Suspended Solids 30.0 100.0 Oil & Grease 15.0 20.0 Copper, Total 1.0 1.0 Iron, Total 1.0 1.0 Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 20

5.1.6 §316(b) of the Clean Water Act (CWA) & Cooling Water Intake Structures

a. The permittee is subject to the Track I requirements applicable to cooling water intake structures for new facilities promulgated at 40 C.F.R. 125 -

Subpart I. The permittee must operate a closed-cycle recirculating cooling water system and must design and construct each cooling water intake structure at the facility to a maximum through-screen design intake velocity of 0.5 ft/s and such that the total design intake flow from all cooling water intake structures at the facility is no greater than 5% of the source water annual mean flow.

b. The permittee must monitor both impingement and entrainment of the commercial, recreational, and forage base fish and shellfish species identified in the Source Water Baseline Biological Characterization data submitted with the application. The monitoring methods used must be consistent with those used for the Source Water Baseline Biological Characterization data.

Biological monitoring shall become effective upon the commencement of commercial operations for Unit 3. Biological monitoring is required at the frequencies identified below for two (2) years following the commencement of operations for Unit 3 and one (1) year following the commencement of commercial operations for Unit 4. After that time, the Director may approve a request for less frequent sampling, if the supporting data shows that less frequent monitoring would still allow for the detection of any seasonal and daily variations in the species and numbers of individuals that are impinged or entrained.

(i) The permittee must collect samples to monitor impingement rates (simple enumeration) for each species over a 24-hour period and no less than once per month when the cooling water intake structure is in operation.

(ii) The permittee must collect samples at least biweekly to monitor entrainment rates (simple enumeration) for each species over a 24-hour period during the primary period of reproduction, larval recruitment, and peak abundance identified during the Source Water Baseline Biological Characterization when the cooling water intake structure is in operation.

c. The permittee must conduct velocity monitoring upon commencement of commercial operations and thereafter, at a frequency of monthly. To conduct velocity monitoring, the permittee must monitor head loss across the screens and correlate the measured value with the design intake velocity. The head loss across the intake screen must be measured at the minimum ambient source water surface elevation (best professional judgement based on hydrological data). The maximum head loss across the screen for each cooling water intake structure must be used to determine compliance with the Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 21

through-screen design intake velocity requirement in Part III.C.6.a of this permit.

d. The permittee must monitor the intake flows at a minimum frequency of daily.

The monitoring must include measuring cooling water withdrawals and blowdown volume. In lieu of daily intake flow monitoring the permittee may monitor the cycles of concentration at a minimum frequency of daily.

Monitoring will be included in the OMR and submitted in accordance with Part I.D of the permit.

e. The permittee must either conduct visual inspections or employ remote monitoring devices on at least a quarterly basis during the period in which the cooling water intake structure is in operation. Such inspections must ensure that the cooling towers operated to comply with 40 CFR 125.84(b) (Track I requirements) are maintained and operated to function as designed. The permittee must prepare an inspection report documenting the inspections or monitoring and the inspection report shall be submitted as an attachment to the DMR in accordance with Part I.D of the permit. The inspection report shall contain the following minimum elements:

(i) Date, time, and location of the inspection or remote monitoring; (ii) Water withdrawal rate during the time of inspection; (iii) Equipment/Technology identified as needing maintenance, repair or replacement, if any; and (iv) Name(s) and signature(s) of the inspector(s)

f. The permittee shall submit an annual status report signed by the responsible corporate officer as an attachment to the DMR due June 15th. The annual status report must include the following items:

(i) Biological monitoring records for each cooling water intake structure as required by Part III.C.6.b of this permit.

(ii) Velocity and head loss monitoring records for each cooling water intake structure as required by Part III.C.6.c of this permit.

(iii) Record of visual or remote inspections as required by Part III.C.6.e of this permit.

g. The permittee shall retain records of all submissions related to the permit application and conditions outlined in Part III.C.6 of this permit until the subsequent permit has been issued.

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 22

5.1.7 Thermal Mixing Zone

a. The approved thermal mixing zone is defined as the segment of the river extending 81 feet downstream from the point of discharge with a width of 22 feet extending from the west riverbank. The downstream sampling location for compliance with the temperature requirement outline in Part I.A.1 of the permit is at the centerline of the downstream edge of the defined mixing zone at a depth of one (1) meter.

b. The permittee shall perform an instream temperature study in the vicinity of outfall number 001 to demonstrate the results of the CORMIX model within the first two years of commercial operation of Vogtle Unit 4 and while all four units (Vogtle Electric Generating Plants, Units 1-4) are operational. The study shall be conducted during the critical periods of the year, the summer months (August - October) and the winter months (December - February) for the maximum and delta T water quality standards.

(i) Prior to performing the temperature study, the permittee shall submit the proposed temperature study plan to EPD for review and approval.

The study, at a minimum, shall include plans to monitor and report effluent temperature and instream monitoring locations at several transects within the receiving water.

(ii) If the field conditions do not exist within the first two years as referenced above (for example, low flows do not exist, the winter months are abnormally warm or other weather and/or field conditions prevent the permittee from performing the temperature study within the referenced timeframe) the permittee may submit a written request to EPD for an extension from the two-year deadline referenced above.

EPD may review the request and make a determination ensuring the temperature study is performed during a representative time period to validate the results of the CORMIX modeling.

5.2 316(b) of Clean Water Act (CWA) Determination Vogtle Electric Generating Plant, Units 3&4 is subject to the cooling water intake structure requirements for new facilities. The permittee has elected to comply with the Track I requirements for facilities that withdraw equal to or greater than 10 MGD promulgated at 40 C.F.R. § 125.84. To comply with the Track I requirements, the facility will operate a closed-cycle recirculating cooling water system with a maximum through-screen design intake velocity of no greater than 0.5 ft/s and a total design intake flow of no greater than 5% of the source water annual mean flow.

Additionally, a facility may be required to implement design and construction technologies or operational measures for minimizing impingement mortality and entrainment in accordance with 40 C.F.R. §§ 125.84(b)(4-5). Such measures are required if there are threatened or endangered or otherwise protected federal, state, or tribal species, or critical Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 23

habitat for these species, within the hydraulic zone of influence of the cooling water intake structure. Shortnose and Atlantic sturgeon may be present in the Savannah River in the vicinity of the facility. Critical habitat for these species is not located within the hydraulic zone of influence of the cooling water intake structure. Compliance with the Track I requirements and the inclusion of a weir wall which prevents the entrainment of sturgeon eggs, which are demersal, are expected to minimize impingement and entrainment.

Consultation with the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Services (USFWS) identified no additional design and construction technologies or operational measures at this time. Thus, based on the information currently available, the permit does not require additional design and construction technologies, or operational measures discussed at 40 C.F.R. §§ 125.84(b)(4-5).

Biological monitoring, velocity monitoring, and visual or remote inspections have been included as permit conditions in accordance with 40 C.F.R. § 125.87. The commencement of monitoring will not be tied to permit issuance, as the cooling water intake structure will not be in operation at this time. In accordance with, 40 C.F.R. § 125.87(c), visual or remote inspections are required at least weekly to ensure that any design and construction technologies required in 40 C.F.R. §§ 125.84(b)(4-5) are maintained and operated to ensure that they will continue to function as designed. The cooling water intake structure does not include any design and construction technologies required in 40 C.F.R. §§ 125.84(b)(4-5),

however; the permit will include daily monitoring of the intake flow as well as quarterly inspections of the cooling towers in order to satisfy the visual or remote inspections and ensure proper maintenance and maximize flow reductions.

5.3 Thermal Mixing Zone Southern Nuclear Operating Company previously completed CORMIX modeling to determine the thermal impacts from the discharge of Vogtle Electric Generating Plant, Units 3&4. EPD has reviewed the modeling results and approved a mixing zone in accordance with the Rules and Regulations of the State of Georgia 391-3-6-.03(10). The approved thermal mixing zone is defined as the segment of the river extending 81 feet downstream from the point of discharge with a width of 22 feet extending from the west riverbank. The permittee will further be required to complete a temperature validation study to confirm the CORMIX modeling once Units 3 & 4 are in operation.

5.4 Compliance Schedules The permittee shall attain compliance with all limits on the effective date of the permit.

5.5 Anti-Backsliding The limits in this permit are in compliance with the 40 C.F.R. 122.44(l), which requires a reissued permit to be as stringent as the previous permit.

Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 24

6.0 REPORTING The facility has been assigned to the following EPD office for reporting, compliance and enforcement.

Georgia Environmental Protection Division Watershed Compliance Program 2 Martin Luther King Jr. Drive Suite 1152 East Atlanta, Georgia 30334 6.1 E-Reporting The permittee is required to electronically submit documents in accordance with 40 CFR Part 127.

7.0 REQUESTED VARIANCES OR ALTERNATIVES TO REQUIRED STANDARDS Not applicable 8.0 PERMIT EXPIRATION The permit will expire five years from the effective date.

9.0 PROCEDURES FOR THE FORMULATION OF FINAL DETERMINATIONS 9.1 Comment Period The Georgia Environmental Protection Division (EPD) proposes to issue a permit to this applicant subject to the effluent limitations and special conditions outlined above. These determinations are tentative.

Georgia Environmental Protection Division Wastewater Regulatory Program 2 Martin Luther King Jr. Drive Suite 1152 East Atlanta, Georgia 30334 The permit application, draft permit, and other information are available for review at 2 Martin Luther King Jr. Drive, Suite 1152 East, Atlanta, Georgia 30334, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday and on EPDs website accessible through the publicly available Georgia EPD Online System (GEOS) at:

https://geos.epd.georgia.gov/GA/GEOS/Public/GovEnt/Shared/Pages/Main/Login.aspx.

For additional information, you can contact 404-463-1511.

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9.2 Public Comments Persons wishing to comment upon or object to the proposed determinations are invited to submit same in writing to the EPD address above, or via e-mail at EPDcomments@dnr.ga.gov within 30 days of the initiation of the public comment period.

All comments received prior to that date will be considered in the formulation of final determinations regarding the application. The permit number should be placed on the top of the first page of comments to ensure that your comments will be forwarded to the appropriate staff.

9.3 Public Hearing Any applicant, affected state or interstate agency, the Regional Administrator of the U.S.

Environmental Protection Agency (EPA) or any other interested agency, person or group of persons may request a public hearing with respect to an NPDES permit application if such request is filed within thirty (30) days following the date of the public notice for such application. Such request must indicate the interest of the party filing the request, the reasons why a hearing is requested, and those specific portions of the application or other NPDES form or information to be considered at the public hearing.

The Director shall hold a hearing if he determines that there is sufficient public interest in holding such a hearing. If a public hearing is held, notice of same shall be provided at least thirty (30) days in advance of the hearing date.

In the event that a public hearing is held, both oral and written comments will be accepted; however, for the accuracy of the record, written comments are encouraged. The Director or a designee reserves the right to fix reasonable limits on the time allowed for oral statements and such other procedural requirements, as deemed appropriate.

Following a public hearing, the Director, unless it is decided to deny the permit, may make such modifications in the terms and conditions of the proposed permit as may be appropriate and shall issue the permit.

If no public hearing is held, and, after review of the written comments received, the Director determines that a permit should be issued and that the determinations as set forth in the proposed permit are substantially unchanged, the permit will be issued and will become final in the absence of a request for a contested hearing. Notice of issuance or denial will be made available to all interested persons and those persons that submitted written comments to the Director on the proposed permit.

If no public hearing is held, but the Director determines, after a review of the written comments received, that a permit should be issued but that substantial changes in the proposed permit are warranted, public notice of the revised determinations will be given and written comments accepted in the same manner as the initial notice of application was given and written comments accepted pursuant to EPD Rules, Water Quality Control, subparagraph 391-3-6-.06(7)(b). The Director shall provide an opportunity for public hearing on the Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 26

revised determinations. Such opportunity for public hearing and the issuance or denial of a permit thereafter shall be in accordance with the procedures as are set forth above.

9.4 Final Determination At the time that any final permit decision is made, the Director shall issue a response to comments. The issued permit and responses to comments can be found at the following address:

http://epd.georgia.gov/watershed-protection-branch-permit-and-public-comments-clearinghouse-0 9.5 Contested Hearings Any person who is aggrieved or adversely affected by the issuance or denial of a permit by the Director of EPD may petition the Director for a hearing if such petition is filed in the office of the Director within thirty (30) days from the date of notice of such permit issuance or denial. Such hearing shall be held in accordance with the EPD Rules, Water Quality Control, subparagraph 391-3-6-.01.

Petitions for a contested hearing must include the following:

1. The name and address of the petitioner;

2. The grounds under which petitioner alleges to be aggrieved or adversely affected by the issuance or denial of a permit;

3. The reason or reasons why petitioner takes issue with the action of the Director;

4. All other matters asserted by petitioner which are relevant to the action in question.

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APPENDIX A - Applicable Federal Regulations Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 28

ELECTRONIC CODE OF FEDERAL REGULATIONS e-CFR data is current as of September 8, 2021 Title 40 Chapter I Subchapter N Part 423 Title 40: Protection of Environment PART 423STEAM ELECTRIC POWER GENERATING POINT SOURCE CATEGORY Contents

§423.10 Applicability.

§423.11 Specialized definitions.

§423.12 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

§423.13 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

§423.14 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

[Reserved]

§423.15 New source performance standards (NSPS).

§423.16 Pretreatment standards for existing sources (PSES).

§423.17 Pretreatment standards for new sources (PSNS).

§423.18 Permit conditions.

§423.19 Reporting and recordkeeping requirements.

Appendix A to Part 423126 Priority Pollutants A : Secs. 101; 301; 304(b), (c), (e), and (g); 306; 307; 308 and 501, Clean Water Act (Federal Water Pollution Control Act Amendments of 1972, as amended; 33 U.S.C. 1251; 1311; 1314(b), (c), (e), and (g); 1316; 1317; 1318 and 1361).

S : 47 FR 52304, Nov. 19, 1982, unless otherwise noted.

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§423.10 Applicability.

The provisions of this part apply to discharges resulting from the operation of a generating unit by an establishment whose generation of electricity is the predominant source of revenue or principal reason for operation, and whose generation of electricity results primarily from a process utilizing fossil-type fuel (coal, oil, or gas), fuel derived from fossil fuel (e.g., petroleum coke, synthesis gas), or nuclear fuel in conjunction with a thermal cycle employing the steam water system as the thermodynamic medium. This part applies to discharges associated with both the combustion turbine and steam turbine portions of a combined cycle generating unit.

[80 FR 67893, Nov. 3, 2015]

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§423.11 Specialized definitions.

In addition to the definitions set forth in 40 CFR part 401, the following definitions apply to this part:

(a) The term total residual chlorine (or total residual oxidants for intake water with bromides) means the value obtained using any of the chlorinetotal residual methods in Table IB in 40 CFR 136.3(a), or other methods approved by the permitting authority.

(b) The term low volume waste sources means, taken collectively as if from one source, wastewater from all sources except those for which specific limitations or standards are otherwise established in this part. Low volume waste sources include, but are not limited to, the following: Wastewaters from ion exchange water treatment systems, water treatment evaporator blowdown, laboratory and sampling streams, boiler blowdown, floor drains, cooling tower basin cleaning wastes, recirculating house service water systems, and wet scrubber air pollution control systems whose primary purpose is particulate removal. Sanitary wastes, air conditioning wastes, and wastewater from carbon capture or sequestration systems are not included in this definition.

(c) The term chemical metal cleaning waste means any wastewater resulting from the cleaning of any metal process equipment with chemical compounds, including, but not limited to, boiler tube cleaning.

(d) The term metal cleaning waste means any wastewater resulting from cleaning [with or without chemical cleaning compounds] any metal process equipment including, but not limited to, boiler tube cleaning, boiler fireside cleaning, and air preheater cleaning.

(e) The term fly ash means the ash that is carried out of the furnace by a gas stream and collected by a capture device such as a mechanical precipitator, electrostatic precipitator, or fabric filter. Economizer ash is included in this definition when it is collected with fly ash. Ash is not included in this definition when it is collected in wet scrubber air pollution control systems whose primary purpose is particulate removal.

(f) The term bottom ash means the ash, including boiler slag, which settles in the furnace or is dislodged from furnace walls. Economizer ash is included in this definition when it is collected with bottom ash.

(g) The term once through cooling water means water passed through the main cooling condensers in one or two passes for the purpose of removing waste heat.

(h) The term recirculated cooling water means water which is passed through the main condensers for the purpose of removing waste heat, passed through a cooling device for the purpose of removing such heat from the water and then passed again, except for blowdown, through the main condenser.

(i) The term 10 year, 24/hour rainfall event means a rainfall event with a probable recurrence interval of once in ten years as defined by the National Weather Service in Technical Paper No. 40. Rainfall Frequency Atlas of the United States, May 1961 or equivalent regional rainfall probability information developed therefrom.

(j) The term blowdown means the minimum discharge of recirculating water for the purpose of discharging materials contained in the water, the further buildup of which would cause concentration in amounts exceeding limits established by best engineering practices.

(k) The term average concentration as it relates to chlorine discharge means the average of analyses made over a single period of chlorine release which does not exceed two hours.

(l) The term free available chlorine means the value obtained using any of the chlorine free available methods in Table IB in 40 CFR 136.3(a) where the method has the capability of measuring free available chlorine, or other methods approved by the permitting authority.

(m) The term coal pile runoff means the rainfall runoff from or through any coal storage pile.

(n) The term flue gas desulfurization (FGD) wastewater means any wastewater generated specifically from the wet flue gas desulfurization scrubber system that comes into contact with the flue gas or the FGD solids, including but not limited to, the blowdown from the FGD scrubber system, overflow or underflow from the solids separation process, FGD solids wash water, and the filtrate from the solids dewatering process. Wastewater generated from cleaning the FGD scrubber, cleaning FGD solids separation equipment, cleaning FGD solids dewatering equipment, FGD paste equipment cleaning water, treated FGD wastewater permeate or distillate used as boiler makeup water, or water that is collected in floor drains in the FGD process area is not considered FGD wastewater.

(o) The term flue gas mercury control wastewater means any wastewater generated from an air pollution control system installed or operated for the purpose of removing mercury from flue gas. This includes fly ash collection systems when the particulate control system follows sorbent injection or other controls to remove mercury from flue gas. FGD wastewater generated at plants using oxidizing agents to remove mercury in the FGD system and not in a separate FGMC system is not included in this definition.

(p) The term transport water means any wastewater that is used to convey fly ash, bottom ash, or economizer ash from the ash collection or storage equipment, or boiler, and has direct contact with the ash. Transport water does not include low volume, short duration discharges of wastewater from minor leaks (e.g., leaks from valve packing, pipe flanges, or piping), minor maintenance events (e.g., replacement of valves or pipe sections), FGD paste equipment cleaning water, or bottom ash purge water (q) The term gasification wastewater means any wastewater generated at an integrated gasification combined cycle operation from the gasifier or the syngas cleaning, combustion, and cooling processes. Gasification wastewater includes, but is not limited to the following:

Sour/grey water; CO2/steam stripper wastewater; sulfur recovery unit blowdown, and wastewater resulting from slag handling or fly ash handling, particulate removal, halogen removal, or trace organic removal. Air separation unit blowdown, noncontact cooling water, and runoff from fuel and/or byproduct piles are not considered gasification wastewater.

Wastewater that is collected intermittently in floor drains in the gasification process area from leaks, spills, and cleaning occurring during normal operation of the gasification operation is not considered gasification wastewater.

(r) The term combustion residual leachate means leachate from landfills or surface impoundments containing combustion residuals. Leachate is composed of liquid, including any suspended or dissolved constituents in the liquid, that has percolated through waste or other materials emplaced in a landfill, or that passes through the surface impoundment's containment structure (e.g., bottom, dikes, berms). Combustion residual leachate includes

seepage and/or leakage from a combustion residual landfill or impoundment unit.

Combustion residual leachate includes wastewater from landfills and surface impoundments located on non-adjoining property when under the operational control of the permitted facility.

(s) The term oil-fired unit means a generating unit that uses oil as the primary or secondary fuel source and does not use a gasification process or any coal or petroleum coke as a fuel source. This definition does not include units that use oil only for start up or flame-stabilization purposes.

(t) The phrase as soon as possible means November 1, 2018 (except for purposes of

§423.13(g)(1)(i) and (k)(1)(i), in which case it means October 13, 2021), unless the permitting authority establishes a later date, after receiving site-relevant information from the discharger, which reflects a consideration of the following factors:

(1) Time to expeditiously plan (including to raise capital), design, procure, and install equipment to comply with the requirements of this part.

(2) Changes being made or planned at the plant in response to:

(i) New source performance standards for greenhouse gases from new fossil fuel-fired electric generating units, under sections 111, 301, 302, and 307(d)(1)(C) of the Clean Air Act, as amended, 42 U.S.C. 7411, 7601, 7602, 7607(d)(1)(C);

(ii) Emission guidelines for greenhouse gases from existing fossil fuel-fired electric generating units, under sections 111, 301, 302, and 307(d) of the Clean Air Act, as amended, 42 U.S.C. 7411, 7601, 7602, 7607(d); or (iii) Regulations that address the disposal of coal combustion residuals as solid waste, under sections 1006(b), 1008(a), 2002(a), 3001, 4004, and 4005(a) of the Solid Waste Disposal Act of 1970, as amended by the Resource Conservation and Recovery Act of 1976, as amended by the Hazardous and Solid Waste Amendments of 1984, 42 U.S.C. 6906(b),

6907(a), 6912(a), 6944, and 6945(a).

(3) For FGD wastewater requirements only, an initial commissioning period for the treatment system to optimize the installed equipment.

(4) Other factors as appropriate.

(u) The term FGD paste means any combination of FGD wastewater treated with fly ash, lime, Portland cement, and/or other pozzolanic material prior to being landfilled, and which is engineered to form a solid through pozzolanic reactions.

(v) The term FGD paste equipment cleaning water means any wastewater generated from the cleaning of pugmills, piping, or other equipment used to make, process, or transport FGD paste from its point of generation to a landfill.

(w) The term permanent cessation of coal combustion means the owner or operator certifies under §423.19(f) that an electric generating unit will cease combustion of coal no later than December 31, 2028.

(x) The term high FGD flow means the maximum daily volume of FGD wastewater that could be discharged by a facility is above 4 million gallons per day after accounting for that facility's ability to recycle the wastewater to the maximum limits for the FGD system materials of construction

of construction.

(y) The term capacity utilization rating means the total MWh production of an electric generating unit over a calendar year divided by the product of the number of hours in that year times the nameplate capacity.

(z) The term low utilization electric generating unit means any electric generating unit for which the facility owner certifies, and annually recertifies, under §423.19(e) that the two-year average annual capacity utilization rating is less than 10 percent.

(aa) The term primary active wetted bottom ash system volume means the maximum volumetric capacity of bottom ash transport water in all non-redundant piping (including recirculation piping) and primary bottom ash collection and recirculation loop tanks (e.g.,

bins, troughs, clarifiers, and hoppers) of a wet bottom ash system, excluding the volumes of surface impoundments, secondary bottom ash system equipment (e.g., installed spares, redundancies, and maintenance tanks), and non-bottom ash transport systems that may direct process water to the bottom ash.

(bb) The term tank means a stationary device, designed to contain an accumulation of wastewater which is constructed primarily of non-earthen materials (e.g., wood, concrete, steel, plastic) which provide structural support.

(cc) The term bottom ash purge water means any water being discharged subject to

§423.13(k)(2)(i) or 423.16(g)(2)(i).

(dd) The term 30-day rolling average means the series of averages using the measured values of the preceding 30 days for each average in the series.

[47 FR 52304, Nov. 19, 1982, as amended at 77 FR 29834, May 18, 2012; 80 FR 67893, Nov. 3, 2015; 82 FR 43500, Sept. 18, 2017; 85 FR 64716, Oct. 13, 2020]

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§423.12 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

(a) In establishing the limitations set forth in this section, EPA took into account all information it was able to collect, develop and solicit with respect to factors (such as age and size of plant, utilization of facilities, raw materials, manufacturing processes, non-water quality environmental impacts, control and treatment technology available, energy requirements and costs) which can affect the industry subcategorization and effluent levels established. It is, however, possible that data which would affect these limitations have not been available and, as a result, these limitations should be adjusted for certain plants in this industry. An individual discharger or other interested person may submit evidence to the Regional Administrator (or to the State, if the State has the authority to issue NPDES permits) that factors relating to the equipment or facilities involved, the process applied, or other such factors related to such discharger are fundamentally different from the factors considered in the establishment of the guidelines. On the basis of such evidence or other available information, the Regional Administrator (or the State) will make a written finding that such factors are or are not fundamentally different for that facility compared to those specified in the Development Document. If such fundamentally different factors are found to exist, the Regional Administrator or the State shall establish for the discharger effluent limitations in the NPDES Permit either more or less stringent than the limitations established herein, to the extent dictated by such fundamentally different factors. Such limitations must

be approved by the Administrator of the Environmental Protection Agency. The Administrator may approve or disapprove such limitations, specify other limitations, or initiate proceedings to revise these regulations. The phrase other such factors appearing above may include significant cost differentials. In no event may a discharger's impact on receiving water quality be considered as a factor under this paragraph.

(b) Any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction by the application of the best practicable control technology currently available (BPT):

(1) The pH of all discharges, except once through cooling water, shall be within the range of 6.0-9.0.

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

(3) The quantity of pollutants discharged from low volume waste sources shall not exceed the quantity determined by multiplying the flow of low volume waste sources times the concentration lised in the following table:

BPT effluent limitations Pollutant or pollutant Maximum for any 1 day Average of daily values for 30 consecutive days shall not property (mg/l) exceed (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (4) The quantity of pollutants discharged in fly ash and bottom ash transport water shall not exceed the quantity determined by multiplying the flow of fly ash and bottom ash transport water times the concentration listed in the following table:

BPT effluent limitations Pollutant or pollutant Maximum for any 1 day Average of daily values for 30 consecutive days shall not property (mg/l) exceed (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (5) The quantity of pollutants discharged in metal cleaning wastes shall not exceed the quantity determined by multiplying the flow of metal cleaning wastes times the concentration listed in the following table:

BPT effluent limitations Pollutant or pollutant Maximum for any 1 day Average of daily values for 30 consecutive days shall not property (mg/l) exceed (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 Copper, total 1.0 1.0 Iron, total 1.0 1.0 (6) The quantity of pollutants discharged in once through cooling water shall not exceed the quantity determined by multiplying the flow of once through cooling water sources times the concentation listed in the following table:

BPT effluent limitations Pollutant or pollutant property Maximum concentration (mg/l) Average concentration (mg/l)

Free available chlorine 0.5 0.2

(7) The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown sources times the concentration listed in the following table:

BPT effluent limitations Pollutant or pollutant property Maximum concentration (mg/l) Average concentration (mg/l)

Free available chlorine 0.5 0.2 (8) 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 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 or chlorination.

(9) Subject to the provisions of paragraph (b)(10) of this section, the following effluent limitations shall apply to the point source discharges of coal pile runoff:

BPT effluent limitations Pollutant or pollutant property Maximum concentration for any time (mg/l)

TSS 50 (10) Any untreated overflow from facilities designed, constructed, and operated to treat the volume of coal pile runoff which is associated with a 10 year, 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months rainfall event shall not be subject to the limitations in paragraph (b)(9) of this section.

(11) The quantity of pollutants discharged in FGD wastewater, flue gas mercury control wastewater, combustion residual leachate, gasification wastewater, or bottom ash purge water shall not exceed the quantity determined by multiplying the flow of the applicable wastewater times the concentration listed in the table 7:

T. 7 P (b)(11)

BPT effluent limitations Average of daily values for 30 consecutive days shall Maximum for any 1 day not exceed Pollutant or pollutant property (mg/L) (mg/L)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (12) 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 in paragraphs (b)(3) through (b)(7), and (b)(11), of this section.

Concentration limitations shall be those concentrations specified in this section.

(13) In the event that wastestreams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (b)(1) through (b)(12) of this section attributable to each controlled waste source shall not exceed the specified limitations for that waste source.

(The information collection requirements contained in paragraph (a) were approved by the Office of Management and Budget under control number 2000-0194)

g g )

[47 FR 52304, Nov. 19, 1982, as amended at 48 FR 31404, July 8, 1983; 80 FR 67894, Nov. 3, 2015; 85 FR 64716, Oct. 13, 2020]

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§423.13 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this part must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

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

(b)(1) For any plant with a total rated electric generating capacity of 25 or more megawatts, the quantity of pollutants discharged in once through cooling water from each discharge point shall not exceed the quantity determined by multiplying the flow of once through cooling water from each discharge point times the concentration listed in the following table:

BAT Effluent Limitations Pollutant or pollutant property Maximum concentration (mg/l)

Total residual chlorine 0.20 (2) 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.

(c)(1) For any plant with a total rated generating capacity of less than 25 megawatts, the quantity of pollutants discharged in once through cooling water shall not exceed the quantity determined by multiplying the flow of once through cooling water sources times the concentration listed in the following table:

BAT effluent limitations Pollutant or pollutant property Maximum concentration (mg/l) Average concentration (mg/l)

Free available chlorine 0.5 0.2 (2) 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 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.

(d)(1) The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the concentration listed below:

BAT effluent limitations Pollutant or pollutant property Maximum concentration (mg/l) Average concentration (mg/l)

Free available chlorine 0.5 0.2

Free available chlorine 0.5 0.2 Pollutant or pollutant property Maximum for Average of daily values for 30 any 1 day consecutive days shall not exceed =

(mg/l) (mg/l)

The 126 priority pollutants (Appendix A) contained in (1) (1) chemicals added for cooling tower maintenance, except:

Chromium, total 0.2 0.2 Zinc, total 1.0 1.0 1No detectable amount.

(2) 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 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.

(3) At the permitting authority's discretion, instead of the monitoring specified in 40 CFR 122.11(b) compliance with the limitations for the 126 priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(e) The quantity of pollutants discharged in chemical metal cleaning wastes shall not exceed the quantity determined by multiplying the flow of chemical metal cleaning wastes times the concentration listed in the following table:

BAT effluent limitations Pollutant or pollutant Maximum for any 1 day Average of daily values for 30 consecutive days shall not property (mg/l) exceed (mg/l)

Copper, total 1.0 1.0 Iron, total 1.0 1.0 (f) [ReservedNonchemical Metal Cleaning Wastes].

(g)(1)(i) FGD wastewater. Except for those discharges to which paragraph (g)(2) or (g)

(3) of this section applies, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table 1 following this paragraph (g)(1)(i). Dischargers must meet the effluent limitations for FGD wastewater in this paragraph by a date determined by the permitting authority that is as soon as possible beginning October 13, 2021, but no later than December 31, 2025.

These effluent limitations apply to the discharge of FGD wastewater generated on and after the date determined by the permitting authority for meeting the effluent limitations, as specified in this paragraph.

T. 5 P (g)(1)(i)

BAT effluent limitations Average of daily values for 30 consecutive days shall Pollutant or pollutant property Maximum for any 1 day not exceed Arsenic, total (ug/L) 18 8 Mercury, total (ng/L) 103 34 Selenium total (ug/L) 70 29

Selenium, total (ug/L) 70 29 Nitrate/nitrite as N (mg/L) 4 3 (ii) For FGD wastewater generated before the date determined by the permitting authority, as specified in paragraph (g)(1)(i), the quantity of pollutants discharged in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed for TSS in §423.12(b)(11).

(2)(i) For any electric generating unit with a total nameplate capacity of less than or equal to 50 megawatts, that is an oil-fired unit, or for which the owner has submitted a certification pursuant to §423.19(f), the quantity of pollutants discharged in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed for TSS in §423.12(b)(11).

(ii) For FGD wastewater discharges from a high FGD flow facility, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table following this paragraph (g)(2)(ii). Dischargers must meet the effluent limitations for FGD wastewater in this paragraph by a date determined by the permitting authority that is as soon as possible beginning October 13, 2021, but no later than December 31, 2023. These effluent limitations apply to the discharge of FGD wastewater generated on and after the date determined by the permitting authority for meeting the effluent limitations, as specified in this paragraph.

T. 6 P (g)(2)(ii)

BAT effluent limitations Average of daily values for 30 consecutive days shall Pollutant or pollutant property Maximum for any 1 day not exceed Arsenic, total (ug/L) 11 8 Mercury, total (ng/L) 788 356 (iii) For FGD wastewater discharges from a low utilization electric generating unit, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table following paragraph (g)(2)(ii). Dischargers must meet the effluent limitations for FGD wastewater in this paragraph by a date determined by the permitting authority that is as soon as possible beginning October 13, 2021, but no later than December 31, 2023. These effluent limitations apply to the discharge of FGD wastewater generated on and after the date determined by the permitting authority for meeting the effluent limitations, as specified in this paragraph.

(3)(i) For dischargers who voluntarily choose to meet the effluent limitations for FGD wastewater in this paragraph, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table following this paragraph (g)(3)(i). Dischargers who choose to meet the effluent limitations for FGD wastewater in this paragraph must meet such limitations by December 31, 2028. These effluent limitations apply to the discharge of FGD wastewater generated on and after December 31, 2028.

T 7 P (g)(3)(i)

Pollutant or pollutant property BAT effluent limitations

Maximum for any 1 day Average of daily values for 30 consecutive days shall not exceed Arsenic, total (ug/L) 5 NA Mercury, total (ng/L) 23 10 Selenium, total (ug/L) 10 NA Nitrate/Nitrite (mg/L) 2.0 1.2 Bromide (mg/L) 0.2 NA TDS (mg/L) 306 149 (ii) For discharges of FGD wastewater generated before December 31, 2023, the quantity of pollutants discharged in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed for TSS in §423.12(b)(11).

(h)(1)(i) Fly ash transport water. Except for those discharges to which paragraph (h)(2) of this section applies, or when the fly ash transport water is used in the FGD scrubber, there shall be no discharge of pollutants in fly ash transport water. Dischargers must meet the discharge limitation in this paragraph by a date determined by the permitting authority that is as soon as possible beginning November 1, 2018, but no later than December 31, 2023. This limitation applies to the discharge of fly ash transport water generated on and after the date determined by the permitting authority for meeting the discharge limitation, as specified in this paragraph. Whenever fly ash transport water is used in any other plant process or is sent to a treatment system at the plant (except when it is used in the FGD scrubber), the resulting effluent must comply with the discharge limitation in this paragraph. When the fly ash transport water is used in the FGD scrubber, the quantity of pollutants in fly ash transport water shall not exceed the quantity determined by multiplying the flow of fly ash transport water times the concentration listed in the table in paragraph (g)(1)(i) of this section.

(ii) For discharges of fly ash transport water generated before the date determined by the permitting authority, as specified in paragraph (h)(1)(i) of this section, the quantity of pollutants discharged in fly ash transport water shall not exceed the quantity determined by multiplying the flow of fly ash transport water times the concentration listed for TSS in

§423.12(b)(4).

(2) For any electric generating unit with a total nameplate generating capacity of less than or equal to 50 megawatts or that is an oil-fired unit, the quantity of pollutants discharged in fly ash transport water shall not exceed the quantity determined by multiplying the flow of fly ash transport water times the concentration listed for TSS in §423.12(b)(4).

(i)(1)(i) Flue gas mercury control wastewater. Except for those discharges to which paragraph (i)(2) of this section applies, there shall be no discharge of pollutants in flue gas mercury control wastewater. Dischargers must meet the discharge limitation in this paragraph by a date determined by the permitting authority that is as soon as possible beginning November 1, 2018, but no later than December 31, 2023. This limitation applies to the discharge of flue gas mercury control wastewater generated on and after the date determined by the permitting authority for meeting the discharge limitation, as specified in this paragraph. Whenever flue gas mercury control wastewater is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge limitation in this paragraph.

(ii) For discharges of flue gas mercury control wastewater generated before the date determined by the permitting authority, as specified in paragraph (i)(1)(i) of this section, the

quantity of pollutants discharged in flue gas mercury control wastewater shall not exceed the quantity determined by multiplying the flow of flue gas mercury control wastewater times the concentration for TSS listed in §423.12(b)(11).

(2) For any electric generating unit with a total nameplate generating capacity of less than or equal to 50 megawatts or that is an oil-fired unit, the quantity of pollutants discharged in flue gas mercury control wastewater shall not exceed the quantity determined by multiplying the flow of flue gas mercury control wastewater times the concentration for TSS listed in §423.12(b)(11).

(j)(1)(i) Gasification wastewater. Except for those discharges to which paragraph (j)(2) of this section applies, the quantity of pollutants in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration listed in the table following this paragraph (j)(1)(i). Dischargers must meet the effluent limitations in this paragraph by a date determined by the permitting authority that is as soon as possible beginning November 1, 2018, but no later than December 31, 2023. These effluent limitations apply to the discharge of gasification wastewater generated on and after the date determined by the permitting authority for meeting the effluent limitations, as specified in this paragraph.

BAT Effluent limitations Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (ug/L) 4 Mercury, total (ng/L) 1.8 1.3 Selenium, total (ug/L) 453 227 Total dissolved solids (mg/L) 38 22 (ii) For discharges of gasification wastewater generated before the date determined by the permitting authority, as specified in paragraph (j)(1)(i) of this section, the quantity of pollutants discharged in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration for TSS listed in

§423.12(b)(11).

(2) For any electric generating unit with a total nameplate generating capacity of less than or equal to 50 megawatts or that is an oil-fired unit, the quantity of pollutants discharged in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration listed for TSS in §423.12(b)(11).

(k)(1)(i) Bottom ash transport water. Except for those discharges to which paragraph (k)

(2) of this section applies, or when the bottom ash transport water is used in the FGD scrubber, there shall be no discharge of pollutants in bottom ash transport water. Dischargers must meet the discharge limitation in this paragraph by a date determined by the permitting authority that is as soon as possible beginning October 13, 2021, but no later than December 31, 2025. This limitation applies to the discharge of bottom ash transport water generated on and after the date determined by the permitting authority for meeting the discharge limitation, as specified in this paragraph. Except for those discharges to which paragraph (k)(2) of this section applies, whenever bottom ash transport water is used in any other plant process or is sent to a treatment system at the plant (except when it is used in the FGD scrubber), the resulting effluent must comply with the discharge limitation in this paragraph. When the bottom ash transport water is used in the FGD scrubber, it ceases to be bottom ash transport

water, and instead is FGD wastewater, which must meet the requirements in paragraph (g) of this section.

(ii) For discharges of bottom ash transport water generated before the date determined by the permitting authority, as specified in paragraph (k)(1)(i) of this section, the quantity of pollutants discharged in bottom ash transport water shall not exceed the quantity determined by multiplying the flow of bottom ash transport water times the concentration for TSS listed in

§423.12(b)(4).

(2)(i)(A) The discharge of pollutants in bottom ash transport water from a properly installed, operated, and maintained bottom ash system is authorized under the following conditions:

(1) To maintain system water balance when precipitation-related inflows are generated from storm events exceeding a 10-year storm event of 24-hour or longer duration (e.g., 30-day storm event) and cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment; or (2) To maintain system water balance when regular inflows from wastestreams other than bottom ash transport water exceed the ability of the bottom ash system to accept recycled water and segregating these other wastestreams is not feasible; or (3) To maintain system water chemistry where installed equipment at the facility is unable to manage pH, corrosive substances, substances or conditions causing scaling, or fine particulates to below levels which impact system operation or maintenance; or (4) To conduct maintenance not otherwise included in paragraphs (k)(2)(i)(A) (1), (2), or (3) of this section and not exempted from the definition of transport water in §423.11(p), and when water volumes cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment.

(B) The total volume that may be discharged for the above activities shall be reduced or eliminated to the extent achievable using control measures (including best management practices) that are technologically available and economically achievable in light of best industry practice. The total volume of the discharge authorized in this subsection shall be determined on a case-by-case basis by the permitting authority and in no event shall such discharge exceed a 30-day rolling average of ten percent of the primary active wetted bottom ash system volume. The volume of daily discharges used to calculate the 30-day rolling average shall be calculated using measurements from flow monitors.

(ii) For any electric generating unit with a total nameplate generating capacity of less than or equal to 50 megawatts, that is an oil-fired unit, or for which the owner has certified to the permitting authority that it will cease combustion of coal pursuant to §423.19(f), the quantity of pollutants discharged in bottom ash transport water shall not exceed the quantity determined by multiplying the flow of the applicable wastewater times the concentration for TSS listed in §423.12(b)(4).

(iii) For bottom ash transport water generated by a low utilization electric generating unit, the quantity of pollutants discharged in bottom ash transport water shall not exceed the quantity determined by multiplying the flow of the applicable wastewater times the concentration for TSS listed in §423.12(b)(4), and shall incorporate the elements of a best management practices plan as described in (k)(3) of this section.

(3) Where required in paragraph (k)(2)(iii) of this section, the discharger shall prepare, implement, review, and update a best management practices plan for the recycle of bottom ash transport water, and must include:

(i) Identification of the low utilization coal-fired generating units that contribute bottom ash to the bottom ash transport system.

(ii) A description of the existing bottom ash handling system and a list of system components (e.g., remote mechanical drag system, tanks, impoundments, chemical addition). Where multiple generating units share a bottom ash transport system, the plan shall specify which components are associated with low utilization generating units.

(iii) A detailed water balance, based on measurements, or estimates where measurements are not feasible, specifying the volume and frequency of water additions and removals from the bottom ash transport system, including:

(A) Water removed from the BA transport system:

(1) To the discharge outfall.

(2) To the FGD scrubber system.

(3) Through evaporation (4) Entrained with any removed ash (5) To any other mechanisms not specified above.

(B) Water entering or recycled to the BA transport system:

(1) Makeup water added to the BA transport water system.

(2) Bottom ash transport water recycled back to the system in lieu of makeup water.

(3) Any other mechanisms not specified above.

(iv) Measures to be employed by all facilities:

(A) Implementation of a comprehensive preventive maintenance program to identify, repair and replace equipment prior to failures that result in the release of bottom ash transport water.

(B) Daily or more frequent inspections of the entire bottom ash transport water system, including valves, pipe flanges and piping, to identify leaks, spills and other unintended bottom ash transport water escaping from the system, and timely repair of such conditions.

(C) Documentation of preventive and corrective maintenance performed.

(v) Evaluation of options and feasibility, accounting for the associated costs, for eliminating or minimizing discharges of bottom ash transport water, including:

(A) Segregation of bottom ash transport water from other process water.

(B) Minimization of the introduction of stormwater by diverting (e.g., curbing, using covers) storm water to a segregated collection system.

) g g y (C) Recycling bottom ash transport water back to the bottom ash transport water system.

(D) Recycling bottom ash transport water for use in the FGD scrubber.

(E) Optimization of existing equipment (e.g., pumps, pipes, tanks) and installing new equipment where practicable to achieve the maximum amount of recycle.

(F) Utilization of in-line treatment of transport water (e.g., pH control, fines removal) where needed to facilitate recycle.

(vi) Description of the bottom ash recycle system, including all technologies, measures, and practices that will be used to minimize discharge.

(vii) A schedule showing the sequence of implementing any changes necessary to achieve the minimized discharge of bottom ash transport water, including the following:

(A) The anticipated initiation and completion dates of construction and installation associated with the technology components or process modifications specified in the plan.

(B) The anticipated dates that the discharger expects the technologies and process modifications to be fully implemented on a full-scale basis, which in no case shall be later than December 31, 2023.

(C) The anticipated change in discharge volume and effluent quality associated with implementation of the plan.

(viii) Description establishing a method for documenting and demonstrating to the permitting/control authority that the recycle system is well operated and maintained.

(ix) Performance of weekly flow monitoring for the following:

(A) Make up water to the bottom ash transport water system.

(B) Bottom ash transport water sluice flow rate (e.g., to the surface impoundment(s),

dewatering bins(s), tank(s), remote mechanical drag system).

(C) Bottom ash transport water discharge to surface water or POTW.

(D) Bottom ash transport water recycle back to the bottom ash system or FGD scrubber.

(l) Combustion residual leachate. The quantity of pollutants discharged in combustion residual leachate shall not exceed the quantity determined by multiplying the flow of combustion residual leachate times the concentration for TSS listed in §423.12(b)(11).

(m) At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of any mass based limitations specified in paragraphs (b) through (l) of this section. Concentration limitations shall be those concentrations specified in this section.

(n) In the event that wastestreams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (a) through (m) of this section attributable to each controlled waste source shall not exceed the specified limitation for that waste source.

(o)(1) Transfer between applicable limitations in a permit. Where, in the permit, the permitting authority has included alternative limits subject to eligibility requirements, upon timely notification to the permitting authority under §423.19(i), a facility can become subject to the alternative limits under the following circumstances:

(i) On or before December 31, 2023 a facility may convert:

(A) From limitations for electric generating units permanently ceasing coal combustion under paragraphs (g)(2)(i) or (k)(2)(ii) of this section to limitations for low utilization electric generating units under paragraphs (g)(2)(iii) or (k)(2)(iii) of this section; or (B) From voluntary incentives program limitations under paragraph (g)(3)(i) of this section or generally applicable limitations under paragraph (k)(1)(i) of this section to limitations for low utilization electric generating units under paragraphs (g)(2)(iii) or (k)(2)(iii) of this section.

(ii) On or before December 31, 2025 a facility may convert (A) From voluntary incentives program limitations under paragraph (g)(3)(i) of this section to limitations for electric generating units permanently ceasing coal combustion under paragraph (g)(2)(i) of this section; or (B) From limitations for electric generating units permanently ceasing coal combustion under paragraphs (g)(2)(i) or (k)(2)(ii) of this section to voluntary incentives program limitations under paragraphs (g)(3)(i) of this section or generally applicable limitations under (k)(1)(i) of this section; or (C) From limitations for low utilization electric generating units under paragraphs (g)(2)

(iii) or (k)(2)(iii) of this section to generally applicable limitations under paragraphs (g)(1)(i) or (k)(1)(i) of this section; or (D) From limitations for low utilization electric generating units under paragraphs (g)(2)

(iii) or (k)(2)(iii) of this section to voluntary incentives program limitations under paragraphs (g)(3)(i) of this section or generally applicable limitations under paragraph (k)(1)(i) of this section; or (E) From limitations for low utilization electric generating units under paragraphs (g)(2)

(iii) or (k)(2)(iii) of this section to limitations for electric generating units permanently ceasing coal combustion under paragraphs (g)(2)(i) and (k)(2)(ii) of this section.

(2) A facility must be in compliance with all of its currently applicable requirements to be eligible to file a notice under §423.19(i) and to become subject to a different set of applicable requirements under paragraph (o)(1) of this section.

(3) Where a facility seeking a transfer under paragraph (o)(1)(ii) of this section is currently subject to more stringent limitations than the limitations being sought, the facility must continue to meet those more stringent limitations.

(The information collection requirements contained in paragraphs (c)(2) and (d)(2) were approved by the Office of Management and Budget under control number 2040-0040. The information collection requirements contained in paragraph (d)(3) were approved under control number 2040-0033)

[47 FR 52304, Nov. 19, 1982, as amended at 48 FR 31404, July 8, 1983; 80 FR 67894, Nov. 3, 2015; 82 FR 43500, Sept. 18, 2017; 85 FR 64716, Oct. 13, 2020]

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§423.14 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). [Reserved]

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§423.15 New source performance standards (NSPS).

(a) 1982 NSPS. Any new source as of November 19, 1982, subject to paragraph (a) of this section, must achieve the following new source performance standards, in addition to the limitations in §423.13 of this part, established on November 3, 2015. In the case of conflict, the more stringent requirements apply:

(1) pH. The pH of all discharges, except once through cooling water, shall be within the range of 6.0-9.0.

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

(3) Low volume waste sources, FGD wastewater, flue gas mercury control wastewater, combustion residual leachate, and gasification wastewater. The quantity of pollutants discharged in low volume waste sources, FGD wastewater, flue gas mercury control wastewater, combustion residual leachate, and gasification wastewater shall not exceed the quantity determined by multiplying the flow of low volume waste sources times the concentration listed in the following table:

NSPS Average of daily values for 30 consecutive days shall not exceed Pollutant or pollutant property Maximum for any 1 day (mg/l) (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (4) Chemical metal cleaning wastes. The quantity of pollutants discharged in chemical metal cleaning wastes shall not exceed the quantity determined by multiplying the flow of chemical metal cleaning wastes times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days any 1 day shall not exceed Pollutant or pollutant property (mg/l) (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 Copper, total 1.0 1.0 Iron, total 1.0 1.0 (5) [Reserved]

(6) Bottom ash transport water. The quantity of pollutants discharged in bottom ash transport water shall not exceed the quantity determined by multiplying the flow of the bottom ash transport water times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days any 1 day shall not exceed Pollutant or pollutant property (mg/l) (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (7) Fly ash transport water. There shall be no discharge of pollutants in fly ash transport water.

(8)(i) Once through cooling water. For any plant with a total rated electric generating capacity of 25 or more megawatts, the quantity of pollutants discharged in once through cooling water from each discharge point shall not exceed the quantity determined by multiplying the flow of once through cooling water from each discharge point times the concentration listed in the following table:

NSPS Maximum concentrations Pollutant or pollutant property (mg/l)

Total residual chlorine 0.20 (ii) Total residual chlorine may only be discharged from any single generating unit for more than two hours per day when 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.

(9)(i) Once through cooling water. For any plant with a total rated generating capacity of less than 25 megawatts, the quantity of pollutants discharged in once through cooling water shall not exceed the quantity determined by multiplying the flow of once through cooling water sources times the concentration listed in the following table:

NSPS Maximum concentration Average concentration Pollutant or pollutant property (mg/l) (mg/l)

Free available chlorine 0.5 0.2 (ii) 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 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.

(10)(i) Cooling tower blowdown. The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the concentration listed below:

NSPS Maximum concentration Average concentration Pollutant or pollutant property (mg/l) (mg/l)

Free available chlorine 0.5 0.2 Pollutant or pollutant property NSPS Maximum Average of for daily values for 30

any 1 day consecutive (mg/l) days shall not exceed (mg/l)

The 126 priority pollutants (appendix A) contained in chemicals added for cooling tower (1) (1) maintenance, except:

Chromium, total 0.2 0.2 zinc, total 1.0 1.0 1No detectable amount.

(ii) 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 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) At the permitting authority's discretion, instead of the monitoring in 40 CFR 122.11(b), compliance with the standards for the 126 priority pollutants in paragraph (a)(10)(i) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(11) Coal pile runoff. Subject to the provisions of paragraph (a)(12) of this section, the quantity or quality of pollutants or pollutant parameters discharged in coal pile runoff shall not exceed the standards specified below:

Pollutant or pollutant property NSPS for any time TSS not to exceed 50 mg/l.

(12) Coal pile runoff. Any untreated overflow from facilities designed, constructed, and operated to treat the coal pile runoff which results from a 10 year, 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months rainfall event shall not be subject to the standards in paragraph (a)(11) of this section.

(13) At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of any mass based limitations specified in paragraphs (a)(3) through (10) of this section. Concentration limits shall be based on the concentrations specified in this section.

(14) In the event that wastestreams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (a)(1) through (13) of this section attributable to each controlled waste source shall not exceed the specified limitation for that waste source.

(b) 2015 NSPS. Any new source as of November 17, 2015, subject to paragraph (b) of this section, must achieve the following new source performance standards:

(1) pH. The pH of all discharges, except once through cooling water, shall be within the range of 6.0-9.0.

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

(3) Low volume waste sources. The quantity of pollutants discharged from low volume waste sources shall not exceed the quantity determined by multiplying the flow of low volume waste sources times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days any 1 day shall not exceed Pollutant or pollutant property (mg/l) (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 (4) Chemical metal cleaning wastes. The quantity of pollutants discharged in chemical metal cleaning wastes shall not exceed the quantity determined by multiplying the flow of chemical metal cleaning wastes times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days any 1 day shall not exceed Pollutant or pollutant property (mg/l) (mg/l)

TSS 100.0 30.0 Oil and grease 20.0 15.0 Copper, total 1.0 1.0 Iron, total 1.0 1.0 (5) [Reserved]

(6) Bottom ash transport water. There shall be no discharge of pollutants in bottom ash transport water. Whenever bottom ash transport water is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(7) Fly ash transport water. There shall be no discharge of pollutants in fly ash transport water. Whenever fly ash transport water is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(8)(i) Once through cooling water. For any plant with a total rated electric generating capacity of 25 or more megawatts, the quantity of pollutants discharged in once through cooling water from each discharge point shall not exceed the quantity determined by multiplying the flow of once through cooling water from each discharge point times the concentration listed in the following table:

NSPS Maximum concentration Pollutant or pollutant property (mg/l)

Total residual chlorine 0.20 (ii) Total residual chlorine may only be discharged from any single generating unit for more than two hours per day when 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.

(9)(i) Once through cooling water. For any plant with a total rated generating capacity of less than 25 megawatts, the quantity of pollutants discharged in once through cooling water shall not exceed the quantity determined by multiplying the flow of once through cooling water sources times the concentration listed in the following table:

NSPS Maximum concentration Average concentration Pollutant or pollutant property (mg/l) (mg/l)

Free available chlorine 0.5 0.2 (ii) 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 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.

(10)(i) Cooling tower blowdown. The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the concentration listed below:

NSPS Maximum concentration Average concentration Pollutant or pollutant property (mg/l) (mg/l)

Free available chlorine 0.5 0.2 NSPS Average of daily values for 30 consecutive Maximum days for shall not any 1 day exceed Pollutant or pollutant property (mg/l) (mg/l)

The 126 priority pollutants (appendix A) contained in chemicals added for cooling tower (1) (1) maintenance, except:

Chromium, total 0.2 0.2 zinc, total 1.0 1.0 1No detectable amount.

(ii) 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 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) At the permitting authority's discretion, instead of the monitoring in 40 CFR 122.11(b), compliance with the standards for the 126 priority pollutants in paragraph (b)(10)(i) of this section may be determined by engineering calculations demonstrating that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(11) Coal pile runoff. Subject to the provisions of paragraph (b)(12) of this section, the quantity or quality of pollutants or pollutant parameters discharged in coal pile runoff shall not exceed the standards specified below:

exceed the standards specified below:

Pollutant or pollutant property NSPS for any time TSS not to exceed 50 mg/l.

(12) Coal pile runoff. Any untreated overflow from facilities designed, constructed, and operated to treat the coal pile runoff which results from a 10 year, 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months rainfall event shall not be subject to the standards in paragraph (b)(11) of this section.

(13) FGD wastewater. The quantity of pollutants discharged in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (ug/L) 4 Mercury, total (ng/L) 39 24 Selenium, total (ug/L) 5 TDS (mg/L) 50 24 (14) Flue gas mercury control wastewater. There shall be no discharge of pollutants in flue gas mercury control wastewater. Whenever flue gas mercury control wastewater is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(15) Gasification wastewater. The quantity of pollutants discharged in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (ug/L) 4 Mercury, total (ng/L) 1.8 1.3 Selenium, total (ug/L) 453 227 Total dissolved solids (mg/L) 38 22 (16) Combustion residual leachate. The quantity of pollutants discharged in combustion residual leachate shall not exceed the quantity determined by multiplying the flow of combustion residual leachate times the concentration listed in the following table:

NSPS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (ug/L) 11 8 Mercury, total (ng/L) 788 356 (17) At the permitting authority's discretion, the quantity of pollutant allowed to be discharged may be expressed as a concentration limitation instead of any mass based limitations specified in paragraphs (b)(3) through (16) of this section. Concentration limits shall be based on the concentrations specified in this section.

(18) In the event that wastestreams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (b)(1) through (16) of this section attributable to each controlled waste source shall not exceed the specified limitation for that waste source.

(The information collection requirements contained in paragraphs (a)(8)(ii), (a)(9)(ii), and (a)(10)(ii),

(b)(8)(ii), (b)(9)(ii), and (b)(10)(ii) were approved by the Office of Management and Budget under control number 2040-0040. The information collection requirements contained in paragraphs (a)(10)

(iii) and (b)(10)(iii) were approved under control number 2040-0033.)

[80 FR 67896, Nov. 3, 2015]

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§423.16 Pretreatment standards for existing sources (PSES).

Except as provided in 40 CFR 403.7 and 403.13, any existing source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources (PSES) by July 1, 1984:

(a) There shall be no discharge of polychlorinated biphenol compounds such as those used for transformer fluid.

(b) The pollutants discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table:

PSES pretreatment standards Pollutant or pollutant property Maximum for 1 day (mg/l)

Copper, total 1.0 (c) [ReservedNonchemical Metal Cleaning Wastes].

(d)(1) The pollutants discharged in cooling tower blowdown shall not exceed the concentration listed in the following table:

PSES pretreatment standards Maximum for any time Pollutant or pollutant property (mg/l)

The 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower (1) maintenance, except:

Chromium, total 0.2 Zinc, total 1.0 1No detectable amount.

(2) At the permitting authority's discretion, instead of the monitoring in 40 CFR 122.11(b),

compliance with the limitations for the 126 priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(e)(1) FGD wastewater. Except as provided for in paragraph (e)(2) of this section, for any electric generating unit with a total nameplate generating capacity of more than 50 megawatts, that is not an oil-fired unit, and that the owner has not certified to the permitting

authority that it will cease the coal combustion pursuant to §423.19(f), the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in table 3 to this paragraph (e)(1).

Dischargers must meet the standards in this paragraph by October 13, 2023 except as provided for in paragraph (e)(2) of this section. These standards apply to the discharge of FGD wastewater generated on and after October 13, 2023.

T. 3 P (e)(1)

PSES Average of daily values for 30 consecutive days shall Pollutant or pollutant property Maximum for any 1 day not exceed Arsenic, total (ug/L) 18 8 Mercury, total (ng/L) 103 34 Selenium, total (ug/L) 70 29 Nitrate/nitrite as N (mg/L) 4 3 (2)(i) For FGD wastewater discharges from a low utilization electric generating unit, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table 4 to paragraph (e)(2)(ii). Dischargers must meet the standards in this paragraph by October 13, 2023.

(ii) If any low utilization electric generating unit fails to timely recertify that the two year average capacity utilization rating of such a electric generating unit is below 10 percent per year as specified in §423.19(e), regardless of the reason, within two years from the date such a recertification was required, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the Table 3 to paragraph (e)(1).

T 4 P (e)(2)(ii)

PSES Average of daily values for 30 consecutive days shall Pollutant or pollutant property Maximum for any 1 day not exceed Arsenic, total (ug/L) 11 8 Mercury, total (ng/L) 788 356 (e)(1) FGD wastewater. Except as provided for in paragraph (e)(2) of this section, for any electric generating unit with a total nameplate generating capacity of more than 50 megawatts, that is not an oil-fired unit, and that the owner has not certified to the permitting authority that it will cease the coal combustion pursuant to §423.19(f), the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in table 3 to this paragraph (e)(1).

Dischargers must meet the standards in this paragraph by October 13, 2023 except as provided for in paragraph (e)(2) of this section. These standards apply to the discharge of FGD wastewater generated on and after October 13, 2023.

T 3 P (e)(1)

Pollutant or pollutant property PSES

Pollutant or pollutant property PSES Maximum for any 1 day Average of daily values for 30 consecutive days shall not exceed Arsenic, total (ug/L) 18 8 Mercury, total (ng/L) 103 34 Selenium, total (ug/L) 70 29 Nitrate/nitrite as N (mg/L) 4 3 (2)(i) For FGD wastewater discharges from a low utilization electric generating unit, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the table 4 to paragraph (e)(2)(ii). Dischargers must meet the standards in this paragraph by October 13, 2023.

(ii) If any low utilization electric generating unit fails to timely recertify that the two year average capacity utilization rating of such a electric generating unit is below 10 percent per year as specified in §423.19(e), regardless of the reason, within two years from the date such a recertification was required, the quantity of pollutants in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the Table 3 to paragraph (e)(1).

T. 4 P (e)(2)(ii)

PSES Average of daily values for 30 consecutive days shall Pollutant or pollutant property Maximum for any 1 day not exceed Arsenic, total (ug/L) 11 8 Mercury, total (ng/L) 788 356 (f) Fly ash transport water. Except when the fly ash transport water is used in the FGD scrubber, for any electric generating unit with a total nameplate generating capacity of more than 50 megawatts and that is not an oil-fired unit, there shall be no discharge of pollutants in fly ash transport water. This standard applies to the discharge of fly ash transport water generated on and after November 1, 2018. Whenever fly ash transport water is used in any other plant process or is sent to a treatment system at the plant (except when it is used in the FGD scrubber), the resulting effluent must comply with the discharge standard in this paragraph. When the fly ash transport water is used in the FGD scrubber, the quantity of pollutants in fly ash transport water shall not exceed the quantity determined by multiplying the flow of fly ash transport water times the concentration listed in the table in paragraph (e) of this section.

(g)(1) Except for those discharges to which paragraph (g)(2) applies, or when the bottom ash transport water is used in the FGD scrubber, for any electric generating unit with a total nameplate generating capacity of more than 50 megawatts, that is not an oil-fired unit, that is not a low utilization electric generating unit, and that the owner has not certified to the permitting authority that the electric generating unit will cease the cessation of coal combustion pursuant to §423.19(f), there shall be no discharge of pollutants in bottom ash transport water. This standard applies to the discharge of bottom ash transport water generated on and after October 13, 2023. Except for those discharges to which paragraph (g)(2) of this section applies, whenever bottom ash transport water is used in any other plant process or is sent to a treatment system at the plant (except when it is used in the FGD scrubber), the resulting effluent must comply with the discharge standard in this paragraph.

), g py g p g p When the bottom ash transport water is used in the FGD scrubber, the quantity of pollutants in bottom ash transport water shall not exceed the quantity determined by multiplying the flow of bottom ash transport water times the concentration listed in the table in paragraph (e) of this section.

(2)(i) The discharge of pollutants in bottom ash transport water from a properly installed, operated, and maintained bottom ash system is authorized under the following conditions:

(A) To maintain system water balance when precipitation-related inflows are generated from a 10-year storm event of 24-hour or longer duration (e.g., 30-day storm event) and cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment; or (B) To maintain system water balance when regular inflows from wastestreams other than bottom ash transport water exceed the ability of the bottom ash system to accept recycled water and segregating these other wastestreams is feasible; or (C) To maintain system water chemistry where current operations at the facility are unable to currently manage pH, corrosive substances, substances or conditions causing scaling, or fine particulates to below levels which impact system operation or maintenance; or (D) To conduct maintenance not otherwise included in paragraphs (g)(2)(i)(A)(1), (2), or (3) of this section and not exempted from the definition of transport water in§423.11(p), and when water volumes cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment.

(ii) The total volume that may be discharged to a POTW for the above activities shall be reduced or eliminated to the extent achievable as determined by the control authority. The control authority may also include control measures (including best management practices) that are technologically available and economically achievable in light of best industry practice. In no event shall the total volume of the discharge exceed a 30-day rolling average of ten percent of the primary active wetted bottom ash system volume. The volume of daily discharges used to calculate the 30-day rolling average shall be calculated using measurements from flow monitors.

(iii) For bottom ash transport water generated by a low utilization electric generating unit, the quantity of pollutants discharged in bottom ash transport water shall incorporate the elements of a best management practices plan as described in §423.13(k)(3).

(g)(1) Except for those discharges to which paragraph (g)(2) applies, or when the bottom ash transport water is used in the FGD scrubber, for any electric generating unit with a total nameplate generating capacity of more than 50 megawatts, that is not an oil-fired unit, that is not a low utilization electric generating unit, and that the owner has not certified to the permitting authority that the electric generating unit will cease the cessation of coal combustion pursuant to §423.19(f), there shall be no discharge of pollutants in bottom ash transport water. This standard applies to the discharge of bottom ash transport water generated on and after October 13, 2023. Except for those discharges to which paragraph (g)(2) of this section applies, whenever bottom ash transport water is used in any other plant process or is sent to a treatment system at the plant (except when it is used in the FGD scrubber), the resulting effluent must comply with the discharge standard in this paragraph.

When the bottom ash transport water is used in the FGD scrubber, the quantity of pollutants in bottom ash transport water shall not exceed the quantity determined by multiplying the flow

of bottom ash transport water times the concentration listed in the table in paragraph (e) of this section.

(2)(i) The discharge of pollutants in bottom ash transport water from a properly installed, operated, and maintained bottom ash system is authorized under the following conditions:

(A) To maintain system water balance when precipitation-related inflows are generated from a 10-year storm event of 24-hour or longer duration (e.g., 30-day storm event) and cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment; or (B) To maintain system water balance when regular inflows from wastestreams other than bottom ash transport water exceed the ability of the bottom ash system to accept recycled water and segregating these other wastestreams is feasible; or (C) To maintain system water chemistry where current operations at the facility are unable to currently manage pH, corrosive substances, substances or conditions causing scaling, or fine particulates to below levels which impact system operation or maintenance; or (D) To conduct maintenance not otherwise included in paragraphs (g)(2)(i)(A)(1), (2), or (3) of this section and not exempted from the definition of transport water in§423.11(p), and when water volumes cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment.

(ii) The total volume that may be discharged to a POTW for the above activities shall be reduced or eliminated to the extent achievable as determined by the control authority. The control authority may also include control measures (including best management practices) that are technologically available and economically achievable in light of best industry practice. In no event shall the total volume of the discharge exceed a 30-day rolling average of ten percent of the primary active wetted bottom ash system volume. The volume of daily discharges used to calculate the 30-day rolling average shall be calculated using measurements from flow monitors.

(iii) For bottom ash transport water generated by a low utilization electric generating unit, the quantity of pollutants discharged in bottom ash transport water shall incorporate the elements of a best management practices plan as described in §423.13(k)(3).

(h) Flue gas mercury control wastewater. For any electric generating unit with a total nameplate generating capacity of more than 50 megawatts and that is not an oil-fired unit, there shall be no discharge of pollutants in flue gas mercury control wastewater. This standard applies to the discharge of flue gas mercury control wastewater generated on and after November 1, 2018. Whenever flue gas mercury control wastewater is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(i) Gasification wastewater. For any electric generating unit with a total nameplate generating capacity of more than 50 megawatts and that is not an oil-fired unit, the quantity of pollutants in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration listed in the table following this paragraph (i). Dischargers must meet the standards in this paragraph by November 1, 2018. These standards apply to the discharge of gasification wastewater generated on and after November 1, 2018.

Pollutant or pollutant property PSES Average of daily values for 30 Maximum for consecutive days any 1 day shall not exceed Arsenic, total (µg/L) 4 Mercury, total (ng/L) 1.8 1.3 Selenium, total (µg/L) 453 227 Total dissolved solids (mg/L) 38 22

[47 FR 52304, Nov. 19, 1982, as amended at 80 FR 67901, Nov. 3, 2015; 82 FR 43500, Sept. 18, 2017; 85 FR 64720, Oct. 13, 2020]

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§423.17 Pretreatment standards for new sources (PSNS).

(a) 1982 PSNS. Except as provided in 40 CFR 403.7, any new source as of October 14, 1980, subject to paragraph (a) of this section, which introduces pollutants into a publicly owned treatment works, must comply with 40 CFR part 403, the following pretreatment standards for new sources, and the PSES in §423.16, established on November 3, 2015. In the case of conflict, the more stringent standards apply:

(1) PCBs. There shall be no discharge of polychlorinated biphenyl compounds such as those used for transformer fluid.

(2) Chemical metal cleaning wastes. The pollutants discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table:

PSNS Maximum for any 1 day Pollutant or pollutant property (mg/L)

Copper, total 1.0 (3) [Reserved]

(4)(i) Cooling tower blowdown. The pollutants discharged in cooling tower blowdown shall not exceed the concentration listed in the following table:

PSNS Maximum for any time Pollutant or pollutant property (mg/L)

The 126 priority pollutants (appendix A) contained in chemicals added for cooling tower (1) maintenance, except:

Chromium, total 0.2 zinc, total 1.0 1No detectable amount.

(ii) At the permitting authority's discretion, instead of the monitoring in 40 CFR 122.11(b),

compliance with the standards for the 126 priority pollutants in paragraph (a)(4)(i) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(5) Fly ash transport water. There shall be no discharge of wastewater pollutants from fly ash transport water.

ash transport water.

(b) 2015 PSNS. Except as provided in 40 CFR 403.7, any new source as of June 7, 2013, subject to this paragraph (b), which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and the following pretreatment standards for new sources:

(1) PCBs. There shall be no discharge of polychlorinated biphenyl compounds such as those used for transformer fluid.

(2) Chemical metal cleaning wastes. The pollutants discharged in chemical metal cleaning wastes shall not exceed the concentration listed in the following table:

PSNS Maximum for 1 day Pollutant or pollutant property (mg/L)

Copper, total 1.0 (3) [Reserved]

(4)(i) Cooling tower blowdown. The pollutants discharged in cooling tower blowdown shall not exceed the concentration listed in the following table:

PSNS Maximum for any time Pollutant or pollutant property (mg/L)

The 126 priority pollutants (appendix A) contained in chemicals added for cooling tower (1) maintenance, except:

Chromium, total 0.2 zinc, total 1.0 1No detectable amount.

(ii) At the permitting authority's discretion, instead of the monitoring in 40 CFR 122.11(b),

compliance with the standards for the 126 priority pollutants in paragraph (b)(4)(i) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

(5) Fly ash transport water. There shall be no discharge of pollutants in fly ash transport water. Whenever fly ash transport water is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(6) FGD wastewater. The quantity of pollutants discharged in FGD wastewater shall not exceed the quantity determined by multiplying the flow of FGD wastewater times the concentration listed in the following table:

PSNS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (µg/L) 4 Mercury, total (ng/L) 39 24 Selenium, total (µg/L) 5 TDS (mg/L) 50 24

(7) Flue gas mercury control wastewater. There shall be no discharge of pollutants in flue gas mercury control wastewater. Whenever flue gas mercury control wastewater is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(8) Bottom ash transport water. There shall be no discharge of pollutants in bottom ash transport water. Whenever bottom ash transport water is used in any other plant process or is sent to a treatment system at the plant, the resulting effluent must comply with the discharge standard in this paragraph.

(9) Gasification wastewater. The quantity of pollutants discharged in gasification wastewater shall not exceed the quantity determined by multiplying the flow of gasification wastewater times the concentration listed in the following table:

PSNS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (µg/L) 4 Mercury, total (ng/L) 1.8 1.3 Selenium, total (µg/L) 453 227 Total dissolved solids (mg/L) 38 22 (10) Combustion residual leachate. The quantity of pollutants discharged in combustion residual leachate shall not exceed the quantity determined by multiplying the flow of combustion residual leachate times the concentration listed in the following table:

PSNS Average of daily values for 30 Maximum for consecutive days Pollutant or pollutant property any 1 day shall not exceed Arsenic, total (µg/L) 11 8 Mercury, total (ng/L) 788 356

[80 FR 67902, Nov. 3, 2015]

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§423.18 Permit conditions.

All permits subject to this part shall include the following permit conditions:

(a) An electric generating unit shall qualify as a low utilization electric generating unit or permanently ceasing the combustion of coal by December 31, 2028, if such qualification would have been demonstrated absent the following qualifying event:

(1) An emergency order issued by the Department of Energy under Section 202(c) of the Federal Power Act, (2) A reliability must run agreement issued by a Public Utility Commission, or (3) Any other reliability-related order or agreement issued by a competent electricity regulator (e.g., an independent system operator) which results in that electric generating unit operating in a way not contemplated when the certification was made; or

(4) The operation of the electric generating unit was necessary for load balancing in an area subject to a declaration under 42 U.S.C. 5121 et seq., that there exists:

(i) An Emergency, or (ii) A Major Disaster, and (iii) That load balancing was due to the event that caused the Emergency or Major Disaster in paragraph (a)(4) of this section to be declared, (b) Any facility providing the required documentation pursuant to §423.19(g) may avail itself of the protections of this permit condition.

[85 FR 64721, Oct. 13, 2020]

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§423.19 Reporting and recordkeeping requirements.

(a) Discharges subject to this part must comply with the following additional reporting requirements.

(b) Signature and certification. Unless otherwise provided below, all certifications and recertifications required in this part must be signed and certified pursuant to 40 CFR 122.22 for direct dischargers or 40 CFR 403.12(l) for indirect dischargers.

(c) Requirements for facilities discharging bottom ash transport water pursuant to

§423.13(k)(2)(i) or 423.16(g)(2)(i).

(1) Initial Certification Statement. For sources seeking to discharge bottom ash transport water pursuant to §423.13(k)(2)(i) or 423.16(g)(2)(i), an initial certification shall be submitted to the permitting authority by the as soon as possible date determined under §423.11(t), or the control authority by October 13, 2023 in the case of an indirect discharger.

(2) Signature and certification. The certification statement must be signed and certified by a professional engineer.

(3) Contents. An initial certification shall include the following:

(A) A statement that the professional engineer is a licensed professional engineer.

(B) A statement that the professional engineer is familiar with the regulation requirements.

(C) A statement that the professional engineer is familiar with the facility.

(D) The primary active wetted bottom ash system volume in §423.11(aa).

(E) Material assumptions, information, and calculations used by the certifying professional engineer to determine the primary active wetted bottom ash system volume.

(F) A list of all potential discharges under §423.13(k)(2)(i)(A)(1) through (4) or

§423.16(g)(2)(i)(A) through (D), the expected volume of each discharge, and the expected frequency of each discharge.

(G) Material assumptions, information, and calculations used by the certifying professional engineer to determine the expected volume and frequency of each discharge including a narrative discussion of why such water cannot be managed within the system and must be discharged.

(H) A list of all wastewater treatment systems at the facility currently, or otherwise required by a date certain under this section.

(I) A narrative discussion of each treatment system including the system type, design capacity, and current or expected operation.

(d) Requirements for a bottom ash best management practices plan.

(1) Initial and annual certification statement. For sources required to develop and implement a best management practices plan pursuant to §423.13(k)(3), an initial certification shall be made to the permitting authority with a permit application or within two years of October 13, 2021, whichever is later, or to the control authority no later than October 13, 2023 in the case of an indirect discharger, and an annual recertification shall be made to the permitting authority, or control authority in the case of an indirect discharger, within 60 days of the anniversary of the original plan.

(2) Signature and certification. The certification statement must be signed and certified by a professional engineer.

(3) Contents for initial certification. An initial certification shall include the following:

(A) A statement that the professional engineer is a licensed professional engineer.

(B) A statement that the professional engineer is familiar with the regulation requirements.

(C) A statement that the professional engineer is familiar with the facility.

(D) The best management practices plan.

(E) A statement that the best management practices plan is being implemented.

(4) Additional contents for annual certification. In addition to the required contents of the initial certification in paragraph (c)(3) of this section an annual certification shall include the following:

(A) Any updates to the best management practices plan.

(B) An attachment of weekly flow measurements from the previous year.

(C) The average amount of recycled bottom ash transport water in gallons per day.

(D) Copies of inspection reports and a summary of preventative maintenance performed on the system.

(E) A statement that the plan and corresponding flow records are being maintained at the office of the plant.

(e) Requirements for low utilization electric generating units.

(1) Notice of Planned Participation. For sources seeking to qualify as a low utilization electric generating units, a Notice of Planned Participation shall be submitted to the permitting authority or control authority no later than October 13, 2021.

(2) Contents. A Notice of Planned Participation shall identify the potential low utilization electric generating unit. The notice shall also include a statement of at least two years' capacity utilization rating data for the most recent two years of operation of each low utilization electric generating unit and a statement that the facility has a good faith belief that each low utilization electric generating unit will continue to operate at the required capacity utilization rating. Where the most recent capacity utilization rating does not meet the low utilization electric generating unit requirement, a discussion of the projected future utilization shall be provided, including material data and assumptions used to make that projection.

(3) Initial and annual certification statement. For sources seeking to qualify as a low utilization electric generating unit under this part, an initial certification shall be made to the permitting authority, or to the control authority in the case of an indirect discharger, no later than December 31, 2023, and an annual recertification shall be made to the permitting authority, or control authority in the case of an indirect discharger, within 60 days of submitting annual electricity production data to the Energy Information Administration.

(4) Contents. A certification or annual recertification shall be based on the information submitted to the Energy Information Administration and shall include copies of the underlying forms submitted to the Energy Information Administration, as well as any supplemental information and calculations used to determine the two year average annual capacity utilization rating.

(f) Requirements for units that will achieve permanent cessation of coal combustion by December 31, 2028.

(1) Notice of Planned Participation. For sources seeking to qualify as an electric generating unit that will achieve permanent cessation of coal combustion by December 31, 2028, under this part, a Notice of Planned Participation shall be made to the permitting authority, or to the control authority in the case of an indirect discharger, no later than October 13, 2021.

(2) Contents. A Notice of Planned Participation shall identify the electric generating units intended to achieve the permanent cessation of coal combustion. A Notice of Planned Participation shall include the expected date that each electric generating unit is projected to achieve permanent cessation of coal combustion, whether each date represents a retirement or a fuel conversion, whether each retirement or fuel conversion has been approved by a regulatory body, and what the relevant regulatory body is. The Notice of Planned Participation shall also include a copy of the most recent integrated resource plan for which the applicable state agency approved the retirement or repowering of the unit subject to the ELGs, certification of electric generating unit cessation under 40 CFR 257.103(b), or other documentation supporting that the electric generating unit will permanently cease the combustion of coal by December 31, 2028. The Notice of Planned Participation shall also include, for each such electric generating unit, a timeline to achieve the permanent cessation of coal combustion. Each timeline shall include interim milestones and the projected dates of completion.

(3) Annual Progress Report. Annually after submission of the Notice of Planned Participation in paragraph (f)(1) of this section, a progress report shall be filed with the permitting authority or control authority in the case of an indirect discharger

permitting authority, or control authority in the case of an indirect discharger.

(4) Contents. An Annual Progress Report shall detail the completion of any interim milestones listed in the Notice of Planned Participation since the previous progress report, provide a narrative discussion of any completed, missed, or delayed milestones, and provide updated milestones.

(g) Requirements for facilities seeking the protections of §423.18.

(1) Certification statement. For sources seeking to apply the protections of the permit conditions in paragraph §423.18, and for each instance that §423.18 is applied, a one-time certification shall be submitted to the permitting authority, or control authority in the case of an indirect discharger, no later than:

(A) In the case of an order or agreement under §423.18(a)(1), 30 days from receipt of the order or agreement attached pursuant to paragraph (g)(2)(B) of this section; or (B) In the case of an Emergency or Major Disaster under §423.18(a)(2), 30 days from the date that a load balancing need arose.

(2) Contents. A certification statement must include the following:

(A) The qualifying event from the list in §423.18(a), the individual or entity that issued or triggered the event, and the date that such an event was issued or triggered.

(B) A copy of any documentation of the qualifying event from the individual or entity listed under paragraph (g)(2)(A) of this section, or, where such documentation does not exist, other documentation with indicia of reliability for the permitting authority to confirm the qualifying event.

(C) An analysis and accompanying narrative discussion which demonstrates that a electric generating unit would have qualified for the subcategory at issue absent the event detailed in paragraph (g)(2)(A), including the material data, assumptions, and methods used.

(3) Termination of need statement. For sources filing a certification statement under paragraph (g)(1) above, and for each such certification statement, a one-time termination of need statement shall be submitted to the permitting authority, or control authority in the case of an indirect discharger, no later than 30 days from when the source is no longer subject to increased production from the qualifying event.

(4) Contents. A termination of need statement must include a narrative discussion including the date the qualifying event terminated, or if it has not terminated, why the source believes the capacity utilization will no longer be elevated to a level requiring the protection of

§423.18.

(h) Requirements for facilities voluntarily meeting the limits in 423.13(g)(3)(i).

(1) Notice of Planned Participation. For sources opting to comply with the Voluntary Incentives Program requirements of section 423.13(g)(3)(i) by December 31, 2028, a Notice of Planned Participation shall be made to the permitting authority no later than October 13, 2021.

(2) Contents. A Notice of Planned Participation shall identify the facility opting to comply with the Voluntary Incentives Program requirements of 423.13(g)(3)(i), specify what technology or technologies are projected to be used to comply with those requirements, and provide a detailed engineering dependency chart and accompanying narrative demonstrating

provide a detailed engineering dependency chart and accompanying narrative demonstrating when and how the system(s) and any accompanying disposal requirements will be achieved by December 31, 2028.

(3) Annual progress report. After submission of the Notice of Planned Participation in paragraph (h)(1), a progress report shall be filed with the permitting authority, or control authority in the case of an indirect discharger.

(4) Contents. An Annual Progress Report shall detail the completion of interim milestones presented in the engineering dependency chart from the Notice of Planned Participation since the previous progress report, provide a narrative discussion of completed, missed, or delayed milestones, and provide updated milestones.

(5) Rollover certification. Where, prior to the effective date, a discharger has already provided a notice to the permitting authority of opting to comply with the Voluntary Incentives Program requirements of §423.13(g)(i), such notice will satisfy paragraph (h)(1) of this section. However, where details required by (h)(2) of this sectionwere missing from the previously provided notice, those details must be provided in the first Annual Progress Report, no later than October 13, 2021.

(i) Requirements for facilities seeking to transfer between applicable limitations in a permit under §423.13(o).

(1) Notice of Planned Participation. For sources which have filed a Notice of Planned Participation under paragraphs (e)(1), (f)(1), or (h)(1) of this section and intend to make changes that would qualify them for a different set of requirements under §423.13(o), a Notice of Planned Participation shall be made to the permitting authority, or to the control authority in the case of an indirect discharger, no later than the dates stated in §423.13(o)(1).

(2) Contents. A Notice of Planned Participation shall include a list of the electric generating units for which the source intends to change compliance alternatives. For each such electric generating unit, the notice shall list the specific provision under which this transfer will occur, the reason such a transfer is warranted, and a narrative discussion demonstrating that each electric generating unit will be able to maintain compliance with the relevant provisions.

(j) Notice of material delay. (1) Notice. Within 30 days of experiencing a material delay in the milestones set forth in paragraphs (f)(2) or (h)(2) of this section and where such a delay may preclude permanent cessation of coal combustion or compliance with the voluntary incentives program limitations by December 31, 2028, a facility shall file a notice of material delay with the permitting authority, or control authority in the case of an indirect discharger.

(2) Contents. The contents of such a notice shall include the reason for the delay, the projected length of the delay, and a proposed resolution to maintain compliance.

[85 FR 64721, Oct. 13, 2020]

Back to Top Appendix A to Part 423126 Priority Pollutants 001 Acenaphthene 002 Acrolein 003 Acrylonitrile

003 Acrylonitrile 004 Benzene 005 Benzidine 006 Carbon tetrachloride (tetrachloromethane) 007 Chlorobenzene 008 1,2,4-trichlorobenzene 009 Hexachlorobenzene 010 1,2-dichloroethane 011 1,1,1-trichloreothane 012 Hexachloroethane 013 1,1-dichloroethane 014 1,1,2-trichloroethane 015 1,1,2,2-tetrachloroethane 016 Chloroethane 018 Bis(2-chloroethyl) ether 019 2-chloroethyl vinyl ether (mixed) 020 2-chloronaphthalene 021 2,4, 6-trichlorophenol 022 Parachlorometa cresol 023 Chloroform (trichloromethane) 024 2-chlorophenol 025 1,2-dichlorobenzene 026 1,3-dichlorobenzene 027 1,4-dichlorobenzene 028 3,3-dichlorobenzidine 029 1,1-dichloroethylene 030 1,2-trans-dichloroethylene 031 2,4-dichlorophenol 032 1,2-dichloropropane 033 1,2-dichloropropylene (1,3-dichloropropene) 034 2,4-dimethylphenol 035 2,4-dinitrotoluene 036 2 6-dinitrotoluene

036 2,6 dinitrotoluene 037 1,2-diphenylhydrazine 038 Ethylbenzene 039 Fluoranthene 040 4-chlorophenyl phenyl ether 041 4-bromophenyl phenyl ether 042 Bis(2-chloroisopropyl) ether 043 Bis(2-chloroethoxy) methane 044 Methylene chloride (dichloromethane) 045 Methyl chloride (dichloromethane) 046 Methyl bromide (bromomethane) 047 Bromoform (tribromomethane) 048 Dichlorobromomethane 051 Chlorodibromomethane 052 Hexachlorobutadiene 053 Hexachloromyclopentadiene 054 Isophorone 055 Naphthalene 056 Nitrobenzene 057 2-nitrophenol 058 4-nitrophenol 059 2,4-dinitrophenol 060 4,6-dinitro-o-cresol 061 N-nitrosodimethylamine 062 N-nitrosodiphenylamine 063 N-nitrosodi-n-propylamin 064 Pentachlorophenol 065 Phenol 066 Bis(2-ethylhexyl) phthalate 067 Butyl benzyl phthalate 068 Di-N-Butyl Phthalate 069 Di-n-octyl phthalate 070 Diethyl Phthalate

070 Diethyl Phthalate 071 Dimethyl phthalate 072 1,2-benzanthracene (benzo(a) anthracene 073 Benzo(a)pyrene (3,4-benzo-pyrene) 074 3,4-Benzofluoranthene (benzo(b) fluoranthene) 075 11,12-benzofluoranthene (benzo(b) fluoranthene) 076 Chrysene 077 Acenaphthylene 078 Anthracene 079 1,12-benzoperylene (benzo(ghi) perylene) 080 Fluorene 081 Phenanthrene 082 1,2,5,6-dibenzanthracene (dibenzo(,h) anthracene) 083 Indeno (,1,2,3-cd) pyrene (2,3-o-pheynylene pyrene) 084 Pyrene 085 Tetrachloroethylene 086 Toluene 087 Trichloroethylene 088 Vinyl chloride (chloroethylene) 089 Aldrin 090 Dieldrin 091 Chlordane (technical mixture and metabolites) 092 4,4-DDT 093 4,4-DDE (p,p-DDX) 094 4,4-DDD (p,p-TDE) 095 Alpha-endosulfan 096 Beta-endosulfan 097 Endosulfan sulfate 098 Endrin 099 Endrin aldehyde 100 Heptachlor 101 Heptachlor epoxide (BHC-hexachlorocyclohexane) 102 Alpha-BHC

102 Alpha BHC 103 Beta-BHC 104 Gamma-BHC (lindane) 105 Delta-BHC (PCB-polychlorinated biphenyls) 106 PCB-1242 (Arochlor 1242) 107 PCB-1254 (Arochlor 1254) 108 PCB-1221 (Arochlor 1221) 109 PCB-1232 (Arochlor 1232) 110 PCB-1248 (Arochlor 1248) 111 PCB-1260 (Arochlor 1260) 112 PCB-1016 (Arochlor 1016) 113 Toxaphene 114 Antimony 115 Arsenic 116 Asbestos 117 Beryllium 118 Cadmium 119 Chromium 120 Copper 121 Cyanide, Total 122 Lead 123 Mercury 124 Nickel 125 Selenium 126 Silver 127 Thallium 126 Silver 128 Zinc 129 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD)

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Appendix B - Wasteload Allocation Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 29

National Pollutant Discharge Elimination System Wasteload Allocation Form Part I: Background Information WLA Request Type:

Facility Name:

Reissuance [8J Expansion Vogtle Electric Generating Plant Units 3 & 4 Relocation County: Burke New Discharge

WQMU: 0112 NPDES Permit No.: GA0039420 Expiration Date: 9/30/2020 Outfall Number: 001 Receiving Water: Savannah River River Basin: Savannah 10-Digit HUC: 0306010611 Discharge Type: Domestic

Industrial [8J Both

Proportion (D:I): Flow Requested (MGD): 11 Industrial Contributions Type(s): Generation, transmission, and distribution of electricity; Plant fuel is nuclear.

Cooling towers associated with circulating water system are used to reduce thermal discharge.

Cooling tower blowdown undergoes chlorination/dechlorination prior to discharge to the mixing chamber. Low volume streams generated throughout the plant have been collected, settled, aerated, Treatment Process

Description:

and/or chemically treated in wastewater retention basins prior to discharge. Sanitary wastes are treated at Units 1 & 2 sewage treatment plant. Radioactive wastes are treated to comply with limitations set by the US Nuclear Regulatory Commission.

Additional Information: (history, special conditions, other facilities): Outfall 001 is the final discharge to the Savannah River.

Requested by: Ian McDowell

Title:

EE Program: WRP Telephone: 404 - 252 - 1567 Date: 6/16/2020 Part II: Receiving Water Information Receiving Water: Savannah River Designated Use Classification: Fishing, Drinking Water Integrated 305(b)/303(d) List: Yes [8J No

Support: [8J Not Support:

Criteria:

Total Maximum Daily Load: Yes

No [8J Parameter(s) WLA Complies with TMDL Yes

No Part III: Water Quality Model Review Information Model Type: Uncalibrated

Calibrated

Verified

Not Modeled [8J Model Length (mi):

Field Data: None Model and Field Data

Description:

Fair

Good

Excellent Critical Water Temperature:(°C): 26 Drainage Area (mi²): 8300 Mean annual streamflow at discharge (cfs): 9500 7Q10 Yield (cfs/mi²): Velocity (range fps): 30Q3 streamflow at discharge (cfs):

Effluent Flow Rate (cfs): 17 IWC (%): 0.4 7Q10 streamflow at discharge (cfs): 3900 Slope (range - fpm): K1: K3: K2 : 1Q10 streamflow at discharge (cfs): 3700 SOD: Escape Coef. (ft-1): f-Ratio BODu/BOD5): Background Hardness (as CaCO3)(mg/L): 14 Part IV: Recommended Permit Limitations and Conditions (lbs/day as a daily average except as noted)

Rationale:

Location:

Same as current Savannah River

Revised [8J New Effluent *Nitrite- *Organic Outfall Flow Rate pH *Total-P *Ortho-P *NH3-N *TKN (MGD)

(std. units) Nitrate Nitrogen 001 Monitor 6.0 - 9.0 Monitor Monitor Monitor Monitor Monitor Monitor Additional Comments:

Priority pollutants permit limits, aquatic toxicity testing requirements, and other parameters required by categorical effluent guidelines or identified during review of permit application are to be determined by WRP.

Nutrient monitoring is recommended for the final outfall 001 if a reasonable potential analysis shows that the effluent may contribute nutrient loadings to the Savannah River. Phosphorus and nitrogen constituents should be analyzed from the same sample for the respective nutrient group.

Prepared Lucy Sun u Date: 6/23/2020 I Reviewed by: Josh Welte JW Date: 26.Jun.20 by:

Part V: Program Manager Comment Elizabeth Booth

~tMc/J()Pii Date: 06/26/2020 i

Georgia Department of Natural Resources Environmental Protection Division Atlanta, Georgia

Richard E. Dunn, Director Watershed Protection Branch 2 Martin Luther King, Jr. Drive Suite 1152, East Tower Atlanta, Georgia 30334 ENVIRONMENTAL PROIECTION DMSION 404-463-1511 Memorandum Date: June 16, 2020 To: Josh Welte Through: Audra Dickson From: Ian McDowell

Subject:

Waste Load Allocation (WLA) Request Vogtle Electric Generating Plant, Units 3 & 4 NPDES Permit No. GA0039420 Burke County, Savannah River Basin WLA request for the reissuance of the above referenced facility, which will expire on September 30, 2020. The analytical analyses accompanying the application for renewal of the NPDES permit indicated the presence of oxygen demanding constituents, nutrients or toxics above detectable limits and the Wastewater Regulatory Program is requesting water quality limits for the permit.

Wastewater Regulatory Program: Permit Information (for each outfall)

(Duplicate this section for each outfall you need a WLA for)

Outfall No.: 001 Lat/Long: 33.148055/-81.752500 Name of Receiving Waters: Savannah River River Basin: Savannah Average Flow (MGD): 11 Maximum (Design) Flow (MGD): 17.9 Summer Temperature (max): 87.8 °F Winter Temperature (max): 53.6 °F Description of Industrial Processes:

Discharges from outfall 001 consist of cooling tower blowdown, low volume waste, liquid radwaste treatment, and radwaste dilution water.

Type of Wastewater Discharge:

Process Wastewater Cooling Water

Stormwater

Domestic Wastewater Other (Radwaste Dilution Water)

Based on a review of the permit application, the following values were reported. WRP is requesting a waste load allocation for water quality limits to meet in-stream Water Quality Standards for the following constituents:

Provide daily average and daily maximum values reported on the application below, with units.

BOD5 3.69 mg/L Total Phosphorus 1.38 mg/L

DO Not Provided TRC <0.1 mg/L

NH3 <0.10 mg/L Temperature 87.8 °F Watershed Planning and Monitoring Program Please provide the following items about the receiving stream and indicate NA if an item does not apply.

7Q10 3900 cfs Receiving Stream Hardness 14 mg/L 30Q3 Upstream TSS 9 mg/L 1Q10 3700 cfs Chronic instream NH3 toxicity 1.23 mg/L Mean Annual Stream Flow 9500 cfs The recommended effluent pH range is 6.0 - 9.0 standard units .

LS 6/24/2020

Wastewater Regulatory Program: Permit Information (for each outfall)

(Duplicate this section for each outfall you need a WLA for)

Outfall No.: 011 Lat/Long: 33.154722/-81.758888 Name of Receiving Waters: Savannah River River Basin: Savannah Average Flow (MGD): 1.4 Maximum (Design) Flow (MGD): 1.72 Summer Temperature (max): 86.4 °F Winter Temperature (max): 48.0 °F Description of Industrial Processes:

Discharges from outfall 011 consist of intake screen backwash from the cooling water intake structure.

Type of Wastewater Discharge:

Process Wastewater

Cooling Water

Stormwater

Domestic Wastewater [g] Other (Intake Screen Backwash)

Based on a review of the permit application, the following values were reported. WRP is requesting a waste load allocation for water quality limits to meet in-stream Water Quality Standards for the following constituents:

Provide daily average and daily maximum values reported on the application below, with units.

BOD5 <2.0 mg/L

Total Phosphorus Not Provided

DO Not Provided

TRC Not Provided

NH3 <0.10 mg/L

Temperature 86.4 °F Watershed Planning and Monitoring Program Please provide the following items about the receiving stream and indicate NA if an item does not apply.

7Q10 3900 cfs Receiving Stream Hardness 14 mg/L 30Q3 Upstream TSS 9 mg/L 1Q10 3700 cfs Chronic instream NH3 toxicity 1.23 mg/L Mean Annual Stream Flow 9500 cfs

Appendix C - Reasonable Potential Analysis Vogtle Electric Generating Plant, Units 3 & 4 December, 2021 NPDES Permit No. GA0039420 Page 30

Reasonable Potential Analysis for Freshwater Permit Name: Vogtle Electric Generating Plant, Units 3&4 NPDES Permit No.: GA0039420 Outfall 001 Stream Data: Effluent Data: Water Quality Criteria:

3 Receiving stream Hardness: 14 mg/L Flow 63,000,000 gal/day Mean annual streamflow at discharge: 9,500.00 ft /s Upstream TSS: 9 mg/L TSS 9.00 mg/L 6,139,584,000 gal/day 3

7Q10: 3,900.00 ft /s Dilution factor: 98.454 2,520,460,800 gal/day Instream TSS: 9.00 mg/L IWC 2.438589353 3

1Q10: ft /s Acute Dilution factor: 38.96 ( )

3,700.00 =

2,391,206,400 gal/day Chronic Dilution factor: 41.01 ( ) + 710( )

Acute Water Quality Criteria (WQCAcute)

Maximum Metal KPO fD Instream CD WQC Acute Action needed?

effluent CT (g/L) (g/L) (g/L)

Arsenic 4.80.E+05 -0.729 0.00 0.00 0.00 340.00 no Cadmium 4.00.E+06 -1.131 0.000 0.00 0.00 0.28 no 1Q10 gal Flow gal day day I I I Chromium III 3.36.E+06 -0.930 0.00 0.00 0.00 113.86 no Chromium VI 3.36.E+06 -0.930 0.00 0.00 0.00 16.00 no Acute Dilution Factor Flow gal I I

Copper 1.04.E+06 -0.744 0.00 0.00 0.00 2.11 no day Lead 2.80.E+06 -0.800 0.00 0.00 0.00 7.20 no Mercury NA NA NA 0.0000 0.0000 1.40 no Nickel 4.90.E+05 -0.572 0.00 0.00 0.00 88.73 no Zinc 1.25.E+06 -0.704 0.29 10.00 0.08 22.15 no Chronic Water Quality Criteria (WQCChronic)

Average effluent Metal KPO fD Instream CD WQC Chronic Action needed?

CT 1 fD (g/L) (g/L) (g/L) 1 K PO TSSInstream(mg/L)(1)106 Arsenic 4.80.E+05 -0.729 0.00 0.00 0.00 150.00 no Effluent CT (mg/L) f D Cadmium 4.00.E+06 -1.131 0.000 0.00 0.00 0.16 no Instream CD mg/L

...==-..:::::::::::::-======--===--====-.I Chromium III 3.36.E+06 -0.930 0.00 0.00 0.00 14.81 no DF I I 1--------+------+-----+----+------l-+-----+-------I Chromium VI 3.36.E+06 -0.930 0.00 0.00 0.00 11.00 no Copper 1.04.E+06 -0.744 0.00 0.00 0.00 1.67 no 7Q10 gal Flow gal Lead 2.80.E+06 -0.800 0.00 0.00 0.00 0.28 no day day Chronic Dilution Factor I

Mercury NA NA NA 0.0000 0.0000 0.012 no Nickel 4.90.E+05 -0.572 0.00 0.00 0.00 9.86 no Flow gal Zinc 1.25.E+06 -0.704 0.29 10.00 0.07 22.33 no day Selenium NA NA NA 0.00 0.00 5.00 no Total Recoverable Effluent Limit Metal CS Chronic CT Chronic CT Acute CT Acute CT (1) WQC Acute (QE 1Q10) (1Q10 CS )

fD (g/L) (g/L) (lbs/day) (g/L) (lbs/day) Acute C T QE 30-Day Avg 30-Day Avg Daily Max Daily Max Arsenic 0.0 N/A N/A N/A N/A Cadmium 0.0 N/A N/A N/A N/A WQC Chronic (QE 7Q10) (7Q10 CS )

Chromium III 0.0 N/A N/A N/A N/A fD Chronic CT QE

- I Chromium VI 0.0 N/A N/A N/A N/A Copper 0.0 N/A N/A N/A N/A (2) WQC Acute (QE 1Q10)

Lead 0.0 N/A N/A N/A N/A fD Acute CT

- -1 QE Mercury 0.0 N/A N/A N/A N/A Nickel 0.0 N/A N/A N/A N/A WQC Chronic (QE 7Q10) fD Zinc 0.0 N/A N/A N/A N/A Chronic CT QE Selenium 0.0 N/A N/A -- --

NOTES:

(1) Chronic and acute total recoverable metal effluent concentration (CT) from EPA 823-B-96-007, June 1996, page 33:

(2) Assuming background dissolved metal concentration (CS) in the stream is 0 g/L, equations above become:

NOTES:

Water Quality Criteria (WQC) from State of Georgia Rules and Regulations 391-3-6-.03.

If the calculated instream concentration is less than 50% of the instream water quality criteria, then the constinuent will be considered not to be present at levels of concern in the effluent and it will not be included in the permit.

If the calculated instream concentration is 50% or more of the instream water quality criteria, then a permit limit for that constinuent will be placed in the permit.

End of report

Reasonable Potential Analysis for Freshwater Permit Name: Vogtle Electric Generating Plant, Units 3&4 NPDES Permit No.: GA0039420 Outfall 011 Stream Data: Effluent Data: Water Quality Criteria:

3 Receiving stream Hardness: 14 mg/L Flow 1,800,000 gal/day Mean annual streamflow at discharge: 9,500.00 ft /s Upstream TSS: 9 mg/L TSS 25.0 mg/L 6,139,584,000 gal/day 3

7Q10: 3,900.00 ft /s Dilution factor: 3411.880 2,520,460,800 gal/day Instream TSS: 9.01 mg/L IWC 0.071364547 3

1Q10: ft /s Acute Dilution factor: 1329.45 ( )

3,700.00 =

2,391,206,400 gal/day Chronic Dilution factor: 1401.26 ( ) + 710( )

Acute Water Quality Criteria (WQCAcute)

Maximum Metal KPO fD Instream CD WQC Acute Action needed?

effluent CT (g/L) (g/L) (g/L)

Arsenic 4.80.E+05 -0.729 0.00 0.00 0.00 340.00 no Cadmium 4.00.E+06 -1.131 0.000 0.00 0.00 0.28 no 1Q10 gal Flow gal day day I I I Chromium III 3.36.E+06 -0.930 0.00 0.00 0.00 113.86 no Chromium VI 3.36.E+06 -0.930 0.00 0.00 0.00 16.00 no Acute Dilution Factor Flow gal I I

Copper 1.04.E+06 -0.744 0.00 0.00 0.00 2.11 no day Lead 2.80.E+06 -0.800 0.00 0.00 0.00 7.20 no Mercury NA NA NA 0.0000 0.0000 1.40 no Nickel 4.90.E+05 -0.572 0.00 0.00 0.00 88.73 no Zinc 1.25.E+06 -0.704 0.00 0.00 0.00 22.15 no Chronic Water Quality Criteria (WQCChronic)

Average effluent Metal KPO fD Instream CD WQC Chronic Action needed?

CT 1 fD (g/L) (g/L) (g/L) 1 K PO TSSInstream(mg/L)(1)106 Arsenic 4.80.E+05 -0.729 0.00 0.00 0.00 150.00 no Effluent CT (mg/L) f D Cadmium 4.00.E+06 -1.131 0.000 0.00 0.00 0.16 no Instream CD mg/L

...==-..:::::::::::::-======--===--====-.I Chromium III 3.36.E+06 -0.930 0.00 0.00 0.00 14.81 no DF I I 1--------+------+-----+----+------l-+-----+-------I Chromium VI 3.36.E+06 -0.930 0.00 0.00 0.00 11.00 no Copper 1.04.E+06 -0.744 0.00 0.00 0.00 1.67 no 7Q10 gal Flow gal Lead 2.80.E+06 -0.800 0.00 0.00 0.00 0.28 no day day Chronic Dilution Factor I

Mercury NA NA NA 0.0000 0.0000 0.012 no Nickel 4.90.E+05 -0.572 0.00 0.00 0.00 9.86 no Flow gal Zinc 1.25.E+06 -0.704 0.00 0.00 0.00 22.33 no day Selenium NA NA NA 0.00 0.00 5.00 no Total Recoverable Effluent Limit Metal CS Chronic CT Chronic CT Acute CT Acute CT (1) WQC Acute (QE 1Q10) (1Q10 CS )

fD (g/L) (g/L) (lbs/day) (g/L) (lbs/day) Acute C T QE 30-Day Avg 30-Day Avg Daily Max Daily Max Arsenic 0.0 N/A N/A N/A N/A Cadmium 0.0 N/A N/A N/A N/A WQC Chronic (QE 7Q10) (7Q10 CS )

Chromium III 0.0 N/A N/A N/A N/A fD Chronic CT QE

- I Chromium VI 0.0 N/A N/A N/A N/A Copper 0.0 N/A N/A N/A N/A (2) WQC Acute (QE 1Q10)

Lead 0.0 N/A N/A N/A N/A fD Acute CT

- -1 QE Mercury 0.0 N/A N/A N/A N/A Nickel 0.0 N/A N/A N/A N/A WQC Chronic (QE 7Q10) fD Zinc 0.0 N/A N/A N/A N/A Chronic CT QE Selenium 0.0 N/A N/A -- --

NOTES:

(1) Chronic and acute total recoverable metal effluent concentration (CT) from EPA 823-B-96-007, June 1996, page 33:

(2) Assuming background dissolved metal concentration (CS) in the stream is 0 g/L, equations above become:

NOTES:

Water Quality Criteria (WQC) from State of Georgia Rules and Regulations 391-3-6-.03.

If the calculated instream concentration is less than 50% of the instream water quality criteria, then the constinuent will be considered not to be present at levels of concern in the effluent and it will not be included in the permit.

If the calculated instream concentration is 50% or more of the instream water quality criteria, then a permit limit for that constinuent will be placed in the permit.

End of report

ND-21-1016, Transmittal of NPDES Permit Issuance

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