STATE OF TENNESSEE 

### DEPARTMENT OF ENVIRONMENT AND CONSERVATION DIVISION OF WATER POLLUTION CONTROL

401 CHURCH STREET L & C ANNEX 6TH FLOOR NASHVILLE TN 37243
Mr. J. Scott Hambrick Plant Manager TVA - Bull Run Fossil Plant (BRF) 1265 Edgemore Rd. BRF 1A-CTT Clinton, TN 37716 Subject: Modification to NPDES Permit No. TN0005410

TVA Bull Run Fossil Plant (BRF) Clinton, Anderson County, Tennessee

Dear Mr. Hambrick: Enclosed please find a draft copy of the modified NPDES Permit No. TN0000078 which the Division of Water Pollution Control (the "Division") proposes to issue. This draft copy is furnished to you solely for your review of its provisions. No wastewater discharges are authorized by this modified permit. The issuance of an official modified permit is contingent upon your meeting all of the requirements of the Tennessee Water Quality Control Act and the Rules and Regulations of the Tennessee Water Quality Control Board. Also enclosed is a copy of the public notice that announces our intent to issue this permit. The notice affords the public an opportunity to review the draft permit and, if necessary, request a public hearing on this issuance process. If you disagree with the provisions and requirements contained in the draft permit, you have twenty-five (25) days from the date of this correspondence to notify the division of your objections. If your objections cannot be resolved, you may appeal this permit upon issuance. This appeal should be filed in accordance with Section 69-3-110 of the Tennessee Code Annotated. If you have questions, please contact the division at the local Environmental Field Office at 1-888-891- TDEC; or, at this office, please contact Bob Alexander at (615) 532-0659 or by E-mail at 

### robertalexander@tn.gov

. Sincerely,

jin Janji6 Manager, Permit Section Division of Water Pollution Control

### cc: DWPC, Permit & Enforcement Sections & Knoxville Environmental Field Office

Ms. Lindy Johnson, TVA, Ipjohnson@tva.gov Ms. Connie A. Kagey, Kagey.Connie@epamail.epa.gov Mr. Scott Gollwitzer, scott@appvoices.org Mr. Aaron Isherwood, aaron.isherwood@sierraclub.org Ms. Kimberly Wilson, lcwilson@environmentalintegrity.org Attorney Adam Kron, akron@defenders.org Ms. Stephanie Matheny, stephanie@tewn.org Mr. Axel Ringe, onyxfarm@bellsouth.net Ms. Abigail Dillen, adillen@earthjustice.org Mr. John McFadden, john mcfadden@attnet Ms. Dana Wright, dana@tcwn.org

# STATE OF TENNESSEE

Paul E. Davis, lir r 

### No. TN0005410 MINOR MODIFICATION Authorization to discharge under the National Pollutant Discharge Elimination System (NPDES) Issued By Tennessee Department of Environment and Conservation

Division of Water Pollution Control

401 Church Street 6th Floor, L & C Annex Nashville, Tennessee 37243-1534 Under authority of the Tennessee Water Quality Control Act of 1977 (T.C.A. 69-3-101 et seq.) and the delegation of authority from the United States Environmental Protection Agency under the Federal Water Pollution Control Act, as amended by the Clean Water Act of 1977 (33 U.S.C. 1251, et seq.)
Discharger: TVA - Bull Run Fossil Plant (BRE) is authorized to discharge: dry fly ash wash down sump, FD fan cooling water, stack yard sump (pulverizer equipment cooling water, boiler bay floor drain), boiler bilge sump (boiler bay floor drainage), non-chemical metal cleaning wastes (boiler fireside washing, air pre-heater washes, precipitator area sump, ducts washing), ash hopper, economizer, pyrite hopper (ash sluice water), hydroveyors (fly ash pumps), precipitator wash down sump (fly ash sump, water from RO treatment), ash pond / gypsum stacking (dewatering facility, flue gas desulfurization (FGD) wastewater system, FGD detention basin / sump, FGD area runoff / drainage, coal yard drainage basin / sump (fly ash stacking area, coal storage area, yard building dust collector sluice, floor drains, roof drains and sumps, coal tower and rail hopper floor / roof drains, utility building roof / floor drains), main station sump (condenser pit sump inflow, equipment cooling water and leakage, service bay floor drainage, emergency overflow from demineralizer sump, leakage from boiler make-up water and water treatment plant, unwatering sump outside powerhouse pumps 1 and 2, yard runoff, electrical yard runoff, back parking lot runoff, roof drains, ash sluice line low point sump), yard drainage basin sump (demineralizer sump (demineralizer system drains), condensate polisher wastes, reject water treatment plant, stack yard sump (equipment cooling water, floor washing wastes), ammonia facility retention pond, ash sluice line low point sump (yard runoff, back parking lot runoff, electrical yard runoff, runoff coal yard pumping basin (coal storage area, fly ash storage area), runoff from ash stacking area, treated metal cleaning waste water (Internal Monitoring Point 005), and direct precipitation on ash pond through Outfall 001; main condenser cooling water (COW), miscellaneous equipment cooling and lubricating water, and roof drains through Outfall 002; intake screen backwash plus intake building sump, discharged to Clinch River via Outfall 004 to cooling water channel from a facility located: in Clinton, Anderson County, Tennessee to receiving waters named: Clinch River at mile 46.3 for Outfall 001, includes (IMP) 005, at mile 48 for Outfalls 002 and 004 in accordance with effluent limitations, monitoring requirements and other conditions set forth herein. This permit shall become effective on: November 1, 2010 This permit shall expire on: November 1, 2013
Issuance date: September 30, 2010

Division of Water Pollution Control

### (This page intentionally left blank.)

iiTABLE OF CONTENTS

Page PART! 1 EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS 1 B. MONITORING PROCEDURES 6 1. Representative Sampling 6 2. Sampling Frequency 6 3. Test Procedures 6 4. Recording of Results 6 5. Records Retention 7 C. REPORTING 7 1. Monitoring Results 7 2. Additional Monitoring by Permittee 7 3. Falsifying Results and/or Reports 7 4. Outlier Data 8 D. SCHEDULE OF COMPLIANCE 8

PART 9 GENERAL PROVISIONS 9 A. GENERAL PROVISIONS 9 1. Duty to Reapply 9 2. Right of Entry 9 3. Availability of Reports 9 4. Proper Operation and Maintenance 9 5. Treatment Facility Failure 10 6. Property Rights 10 7. Severability 10 8. Other Information 10 B. CHANGES AFFECTING THE PERMIT 10 1. Planned Changes 10 2. Permit Modification, Revocation, or Termination 10 3. Change of Ownership 11 4. Change of Mailing Address 12 C. NONCOMPLIANCE 12 1. Effect of Noncompliance 12 2. Reporting of Noncompliance 12 3. Upset 13 4. Adverse Impact 13 5. Bypass 13 6. Washout 14 D. LIABILITIES 14 1. Civil and Criminal Liability 14 2. Liability Under State Law 15PART III 16 OTHER REQUIREMENTS 16 A. ASH POND CLOSURE PLAN 16 B. DIKE INSPECTIONS MODIFIED MAY 13, 2011 16 C. TOXIC POLLUTANTS 18 D. HEAVY METALS MONITORING 18 E. REOPENER CLAUSE 19 E. PLACEMENT OF PUBLIC NOTIFICATION SIGNS 19 F. ANTIDEGRADATION 19 G. MACROINVERTEBRATE CONTROL MEASURES - BIOCIDE/CORROSION TREATMENT PLAN (B/CTP) 22 H. RE-ROUTING FLOWS FOR MAINTENANCE PURPOSES 23 I. FACILITY INTAKE WATER QuALITy MONITORING REQUIREMENTS 23 J. ALTERNATE THERMAL LIMITATION, SECTION 316(A) OF THE CWA 23 K. COOLING WATER INTAKE STRUCTURES - PHASE II, SECTION 316(B) OF THE CWA 23 L. AMMONIA NITROGEN, TOTAL 23 M. EMERGENCY RESPONSE PLAN 24

PART IV 25 BEST MANAGEMENT PRACTICES 25

PART V 25 STORM WATER POLLUTION PREVENTION PLAN 25

PART VI 26 Definitions and Acronyms 26 DEFINITIONS 26 ACRONYMNS AND ABBREVIATIONS 28

RATIONALE FOR MODIFICATION, MAY 2011 1
NOTICE OF DETERMINATION August 2010 1 Comments on Draft Permit and TDEC Responses 1 BEST PROFESSIONAL JUDGMENT ANALYSIS 17 Conclusion — Permit Writer's Best Professional Judgment 34 Attachment 1 41 BEST MANAGEMENT PRACTICES 41

RATIONALE, JANUARY 2010 1 I. DISCHARGER 1 II. PERMIT STATUS 1 III. FACILITY DISCHARGES AND RECEIVING WATERS 2 IV. APPLICABLE EFFLUENT LIMITATIONS GUIDELINES 3 V. PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS 3 VI. HISTORICAL MONITORING AND INSPECTION 3 VII. NEW PERMIT LIMITS AND MONITORING REQUIREMENTS 4 A. TVA COAL BYPRODUCT PROCESS CONVERSION 4 B. DIKE INSPECTIONS 5 C. ASH POND VOLUME 6 F. USE OF TOXIC CHEMICALS 7 G. MACROINVERTEBRATE CONTROL MEASURES 7H. RE-ROUTING FLOWS FOR MAINTENANCE PURPOSES 7 I. HEAVY METALS MONITORING 8 J. PROCEDURES FOR WATER QUALITY BASED EFFLUENT STANDARDS K. EFFLUENT REQUIREMENTS FOR OUTFALL 001, ASH POND 8 1. BIOMONITORING REQUIREMENTS, CHRONIC 8 2. AMMONIA NITROGEN 9 3. OUTFALL 001 ASH POND DISCHARGE OF METALS 12 4. OUTFALL 001 - PH 15 1. BIOMONITORING REQUIREMENTS, CHRONIC 15 M. OUTFALL 004 16 N. INTERNAL MONITORING POINT 005 16 0. USE OF TREATED EFFLUENT FOR DUST CONTROL ON ROADS 17 P. 316(h) -COMPLIANCE WITH SECTION 316, CLEAN WATER ACT 17 1. 316(A) POTENTIAL THERMAL EFFECTS ON A BALANCED INDIGENOUS POPULATION OF AQUATIC LIFE 17 2. 316 (B) - COOLING WATER INTAKE STRUCTURE-316(B) 18
APPENDIX 1. 20
FACILITY DISCHARGES AND RECEIVING WATERS 20
APPENDIX 2 23

APPENDIX 3 28 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS 28 APPENDIX 3 (CONTINUED) 29 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS 29 APPENDIX 3 (CONTINUED) 30 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS 30
APPENDIX 4 31

HISTORICAL MONITORING AND INSPECTION 31
OUTFALL 001 - - 2005 - 09 31 APPENDIX 4 32 HISTORICAL MONITORING AND INSPECTION 32 APPENDIX 4 33 HISTORICAL MONITORING AND INSPECTION 33
APPENDIX 5A 34
PROCEDURES FOR DETERMINING WATER QUALITY BASED EFFLUENT LIMITS 34

APPENDIX 5B 38

DETERMINING ASH POND FREE WATER VOLUME 38

APPENDIX 5C 39
WATER QUALITY BASED EFFLUENT CALCULATIONS 39

APPENDIX 5D 40

COMPARISON OF EFFLUENT LIMITS 40APPENDIX 6 41

NEW PERMIT LIMITS 41

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 1 of 29 PART I EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS

A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS TVA-Bull Run Fossil Plant (BRF) is authorized to discharge: Outfall 001: ash pond effluent consisting of dry fly ash wash down sump, FD fan cooling water, stack yard sump (pulverizer equipment cooling water, boiler bay floor drain), boiler bilge sump (boiler bay floor drainage), non-chemical metal cleaning wastes (boiler fireside washing, air pre-heater washes, precipitator area sump, ducts washing), ash hopper, economizer, pyrite hopper (ash sluice water), hydroveyors (fly ash pumps), precipitator wash down sump (fly ash sump, water from RO treatment), ash pond / gypsum stacking (dewatering facility, flue gas desulfurization (FGD) wastewater system, FGD detention basin / sump, FGD area runoff / drainage, coal yard drainage basin I sump (fly ash stacking area, coal storage area, yard building dust collector sluice, floor drains, roof drains and sumps, coal tower and rail hopper floor / roof drains, utility building roof / floor drains), main station sump (condenser pit sump inflow, equipment cooling water and leakage, service bay floor drainage, emergency overflow from demineralizer sump, leakage from boiler make-up water and water treatment plant, unwatering sump outside powerhouse pumps 1 and 2, yard runoff, electrical yard runoff, back parking lot runoff, roof drains, ash sluice line low point sump), yard drainage basin sump (demineralizer sump (demineralizer system drains), condensate polisher wastes, reject water treatment plant, stack yard sump (equipment cooling water, floor washing wastes), ammonia facility retention pond, ash sluice line low point sump (yard runoff, back parking lot runoff, electrical yard runoff, runoff coal yard pumping basin (coal storage area, fly ash storage area), runoff from ash stacking area, treated metal cleaning waste water (Internal Monitoring Point 005), and direct precipitation on ash pond through Outfall 001pond Outfall 002:

Main condenser cooling water (CCW), miscellaneous equipment cooling and lubricating water, and roof drains through Outfall 002. Outfall 004:

intake screen backwash plus intake building sump, discharged to Clinch River via Outfall 004 to cooling water channel Internal Monitoring Point 005: Via Outfall 001 - Metal Cleaning waste pond, boiler chemical cleaning, air preheater washing through Outfall 001.

These discharges shall be limited and monitored by the permittee as specified below:TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 2 of 29
PERMIT LIMITS 

### OUT FAL L 001 EFFLUENT LIMITATIONS MONITORING MONTHLY DAILY REQUIREMENTS EFFLUENT AVG. CONC. AVG. AMNT MAX CONC. MAX AMNT MS RMNT. SAMPLE CHARACTERISTIC (mg/1) (lb/day) (mgin (lb/day) ERQ NC Y. TYPE FLOW Report (MGD) * Report (MGD) * 1/Week Instantaneous pH ** Range 6.0 - 9.0 1NVeek Grab OIL & GREASE 12.0 -- 16.0 -- 1/Month Grab TOTAL SUSPENDED SOLIDS (TSS) 26.0 -- 84.0 -- 1/Month Grab NITROGEN, AMMONIA TOTAL (Plant

Intake) -- -- Report Report 1/Month Grab NITROGEN, AMMONIA TOTAL

(Effluent) .. -- Report Report 1/Month Grab NITROGEN, AMMONIA TOTAL (Net

Discharge) -- -- Report   Report 1/Month Calculated ALUMINUM, TOTAL -- -- Report

.... 1/Month Grab ANTIMONY, TOTAL -- -- Report -- 1/Month Grab ARSENIC, TOTAL — — Report -- 1/Month Grab BARIUM, TOTAL -- -- Report -- 1/Month Grab BERYLLIUM, TOTAL -- - Report -- i 1/Month Grab CADMIUM, TOTAL -- -- Report -- 1/Month Grab CHROMIUM, TOTAL -- -- Report -- 1/Month Grab COPPER,TOTAL -- -- Report -- 1/Month Grab IRON,TOTAL -- -- Report -- 1/Month Grab LEAD, TOTAL -- -- Report -- 1/Month Grab MERCURY, TOTAL -- -- Report -- 1/Month Grab NICKEL, TOTAL -- -- Report -- 1/Month Grab SELENIUM, TOTAL -- -- Report -- 1/Month Grab SILVER, TOTAL -- -- Report -- 1/Month Grab THALLIUM, TOTAL -- -- Report -- 1/Month Grab ZINC, TOTAL -- -- Report -- 1/Month Grab CYANIDE, TOTAL -- -- Report -- 1/Month Grab 1C25 Report (serial dilutions) Once/permi Grab ** *

Note: The permittee shall take reasonable steps to prevent discharge of cenospheres other than in trace amounts from the outfall. Flow shall be reported in Million Gallons per Day (MGD). ** pH analyses shall be performed within fifteen (15) minutes of sample collection. ** See Part III for methodology. **** If a calculated value for net addition of ammonia as nitrogen exceeds an action concentration value of 1.0 mg/L, the permittee should investigate source(s) of ammonia, and proceed with a corrective action(s), if necessary. Furthermore, Knoxville EFO shall be notified within 24 hours from the time the permittee receives results indicating that an action value of 1.0 mg/L was exceeded

a. For Outfall 001 — monitoring and reporting of toxic metals will be conducted on a monthly basis for twelve (12) reporting periods. At the end of 12 months reporting, TVA and TDEC will evaluate the frequency for further monitoring.

### TVA-Bulk Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 3 of 29

PERMIT LIMITS OUTFALL 002
EFFLUENT LIMITATIONS I MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. AM NT. MAX. CONC. MAX. AMNT. MSRMNT. FRONCY. SAMPLE TYPE ( 111 41A) (Ibiday) (moll) (1b/day) FLOW TIAN Report (MGD) Report (MGD) 1 /Day Estimate 1 TEMPERATURE, Intake Report -- Report -- 1 / Day Grab TEMPERATURE, Effluent .. 3t1°C (88°F) 1 / Day Calculated 2 TOTAL RESIDUAL OXIDANT (reported as chlorine) 3 0.011 -- 0.019 -- 1 /Week 4 Grab
TIME OF OXIDANT ADDITION (minute/day/unit) -- 120 5 1 / Day Log Records IC25 Survival, Reproduction, & Growth in 100% Effluent Once 6 Composite 6

1 Flow shall be estimated from pump logs and reported in Million Gallons per Day (MGD).

2. Intake temperature is measured hourlyand reported as the average of the hourly measurements for each day. The daily mak m urn discharge temperature shall be calculated for the cooling channel based on the 24-hour average intake temperature, 24-hour average unit load, and the 24-hour average flow through Outfall 002
3 Total Residual Oxidant (IRO) monitoring shall be applicable when bromine or any other oxidants are added. The acceptable methods for analysis of TRO are any methods specified in 40 CFR, Part 136. 4. Except for periods of macroinverlebrate control when mdclant addition is required (see Permit - Part Ill), samples shall be taken once at the beginning of the period of chlorination for one unit and once every 15 minutes thereafter. At the end of the period of chlorination, one sample shall be taken. Sampling for these midants is not required when there is no chlorine/bromine added during that day. 5. Application of a oxidant (Prom Ina/chlorine) beyond the 120 minutes per day will be allowed to facilitate nuisance macroinvertebrate control according to the Plan for such activities described in Permit- Part III
6 See Part III for methodology. Toxicity tests shall be periormaed only if biocides are added to the cooling water.

sheen and the permitee waters in a way that Ii OUTFALL 004 Intake Screen Backwash Water Plus Intake Building Sump

No numerical limitations or monitoring requirements. The discharge shall not have a visible oil shall take reasonable steps to prevent the return of materials collected on the screens to the receiving causes an unattractive condition on the recieving waters.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 4 of 29

,_.._ OUTFALL 005 

### Metal c leaning wastes

EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. AMT. MAX CO NC. MAX AND7 T. P4SRMNT. FRQ NCY. SAMPI.E

TYPE (.14A) (112klity) (me) abida y) FLOW Report MGD) * Report MGD)' 1/Batch Estimate** Total Suspended Solids 30.0 -- 100.0 -- Grab Oland Grease 15.0 20.0 -- Grab COPPER,TOTAL 1.0 — 1.0 -- — Grab IRON, TOTAL 1.0 — 1.0 -- Grab
now shalt be reported in Million Gallons per Day (MGD). " Flaw shall be estimated tam pump logs.

— Samples shall be taken at the beginning and end of a discharge event ton each batch treated. 

### Modification, May 2011 During the process of closure of the Chemical Pond, TVA Bull Run Fossil Plant is authorized to discharge rain water from the Chemical Pond into the Ash Pond (Outfall 001)without requirements to monitor the discharge at the Chemical Pond (IMP005). TVA will put in place a procedure to ensure that no wastewater will be discharged into the Chemical Pond. In accordance with the Closure Plan for the Chemical Pond, TVA will decant or dewater the chemical pond wastewater, and will monitor the discharge from the Ash Pond (Outfall 001) for constituents listed under IMP005 discharge at the Ash Pond Discharge (Outfall 001). Monitoring will include sampling prior to decanting / dewatering the Chemical Pond, at least once per day during the decanting I dewatering of the Chemical Pond, and once 24-hours after the decanting has concluded. TVA will monitor for Total Suspended Solids (TSS), Oil and Grease (O&G), Total Copper, and Total Iron at Outfall 001. Multiple decanting / dewatering events may be necessary during closure to prevent water from accumulating in the pond. TVA will monitor each decanting / dewatering event as described above.

PERMIT LIMITS

RAW WATER INTAKE MONITORING The permittee shall continue to monitor facility intake water for the following effluent characteristics (in mg/I): Hardness (as CaCO 3 ), TSS, Aluminum, Antimony, Arsenic, Cadmium, Chromium, Copper, Iron, Lead, Manganese, Mercury, Nickel, Selenium, Silver, Zinc, and Cyanide. All metals shall be reported as Total Recoverable Metal. All samples reported as "Below Detection Level" shall be analyzed to the Required Detection Level (RDL) specified in Tennessee General Water Quality Criteria, Chapter 1200-4-3-.05(8), except for Mercury which shall be analyzed by EPA Method 1631 or 245.7. Samples shall be taken annually with at least 30 days between samples.



### Additional monitoring requirements and conditions applicable to Outfall 001, 002, 004, and 005 include:

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 5 of 29 b. There shall be no distinctly visible floating scum, oil or other matter contained in the wastewater discharge. The wastewater discharge shall not cause an objectionable color contrast in the receiving stream.

c. The wastewater discharge shall not contain pollutants in quantities that will be hazardous or otherwise detrimental to humans, livestock, wildlife, plant life, or fish and aquatic life in the receiving stream. The discharge activity shall not cause or contribute to violations of water quality criteria as stated in the TDEC Rules, Chapter 1200-4-3-.03. Under no circumstances may discharges exceed numeric water quality criteria for aquatic and human life as stated in State of Tennessee Rule 1200-4-3.
d. Sludge or any other material removed by any treatment works must be disposed of in a manner, which prevents its entrance into or pollution of any surface or subsurface waters. Additionally, the disposal of such sludge or other material must be in compliance with the Tennessee Solid Waste Disposal Act, TCA 68-31-101 et seq. and the Tennessee Hazardous Waste Management Act, TCA 68-46-101 et seq.

e. The intake screen backwash discharged through Outfall 004 shall not contain materials other than those naturally occurring in the intake water. The discharge shall not have visible oil/petroleum sheen.
f. For the batch discharges from Outfall (IMP) 005: monitoring and reporting of measurements of FLOW, the "Monthly Avg." shall be the total flow volume during the reporting period divided by the number of calendar days in that period. The "Daily Max." shall be the total flow volume for the day with the greatest amount of discharge during the reporting period. Example: 3 discharges of 15,000 gallons/day and 1 discharge of 20,000 gallons/day during a 1-month period results in a Monthly Avg. of 65,000 gallons/30 days, or 2,166 gallons/day (to be reported as 0.002166 MGD). The Daily Maximum to be reported for this example is 20,000 gallons/day or 0.020 MGD.
g. 40 CFR Part 423.12 (b) (2) (BPT) and Part 423.13 (a) (BAT) specify, "There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid."
h. Total residual oxidant (TRO) monitoring shall be applicable when bromine or any other oxidants are added. The acceptable methods for analysis of TRO are any methods specified in Title 40 CFR, Part 136 as amended.
i. For Outfall 001 monitoring and reporting for thallium, the renewed permit will require reporting of Thallium using Method 200.8 to obtain 12 monthly data points. At the end of 12 months reporting, TVA and TDEC will evaluate the need for further monitoring.

### May 2011

B. MONITORING PROCEDURES
1. Representative Sampling TVA-Bull Run Fossil Plant MODIFICATION to NPDES Permit TN0005410 Page 6 of 29

Samples and measurements taken in compliance with the monitoring requirements specified herein shall be representative of the volume and nature of the monitored discharge, and shall be taken after treatment and prior to mixing with uncontaminated storm water runoff or the receiving stream. 2. Sampling Frequency Where the permit requires sampling and monitoring of a particular effluent characteristic(s) at a frequency of less than once per day or daily, the permittee is precluded from marking the "No Discharge" block on the Discharge Monitoring Report if there has been any discharge from that particular outfall during the period which coincides with the required monitoring frequency, i.e. if the required monitoring frequency is once per month or 1/month, the monitoring period is one month, and if the discharge occurs during only one day in that period then the permittee must sample on that day and report the results of analyses accordingly
3. Test Procedures

a. Test procedures for the analysis of pollutants shall conform to regulations published pursuant to Section 304 (h) of the Clean Water Act (the "Act"), as amended, under which such procedures may be required. Analyses of total mercury will use either EPA Method 245.7 or Method 1631.
b. Unless otherwise noted in the permit, all pollutant parameters shall be determined according to methods prescribed in Title 40, CFR Part 136, as amended, promulgated pursuant to Section 304 (h) of the Act. 4. Recording of Results For each measurement or sample taken pursuant to the requirements of this permit, the permittee shall record the following information:

a. The exact place, date and time of sampling;
b. The exact person(s) collecting samples;

c. The dates and times the analyses were performed;
d. The person(s) or laboratory who performed the analyses;

e. The analytical techniques or methods used, and;
f. The results of all required analyses.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 7 of 29 5. Records Retention All records and information resulting from the monitoring activities required by this permit including all records of analyses performed and calibration and maintenance of instrumentation shall be retained for a minimum of three (3) years, or longer, if requested by the Division of Water Pollution Control.

C. REPORTING

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

TENNESSEE DEPT. OF ENVIRONMENT & CONSERVATION DIVISION OF WATER POLLUTION CONTROL COMPLIANCE REVIEW SECTION 401 CHURCH STREET, NASHVILLE TN 37243-1534 The first DMR is due to be postmarked by the fifteenth of the month following permit effectiveness. DMRs and any other information or report must be signed and certified by a responsible corporate officer as defined in 40 CFR 122.22, a general partner or proprietor, or a principal municipal executive officer or ranking elected official or his duly authorized representative. Such authorization must be submitted in writing and must explain the duties and responsibilities of the authorized representative. The electronic submission of DMRs will be accepted only if approved in writing by the division. For purposes of determining compliance with this permit, data submitted electronically is legally equivalent to data submitted on signed and certified DMR forms.
2. Additional Monitoring by Permittee If the permittee monitors any pollutant specifically limited by this permit more frequently than required at the location(s) designated, using approved analytical methods as specified herein, the results of such monitoring shall be included in the calculation and reporting of the values required in the DMR form. Such increased frequency shall also be indicated on the form.
3. Falsifying Results and/or Reports Knowingly making any false statement on any report required by this permit or falsifying any result may result in the imposition of criminal penalties as provided for in Section 309 of the Federal Water Pollution Control Act, as amended, and in Section 69-3-115 of the Tennessee Water Quality Control Act.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 8 of 29 4. Outlier Data Outlier data include analytical results that are probably false. The validity of results is based on operational knowledge and a properly implemented quality assurance program. False results may include laboratory artifacts, potential sample tampering, broken or suspect sample containers, sample contamination or similar demonstrated quality control flaw. Outlier data are identified through a properly implemented quality assurance program, and according to ASTM standards (e.g. Grubbs Test, 'h' and 'k' statistics). Furthermore, outliers should be verified, corrected, or removed, based on further inquiries into the matter. If an outlier was verified (through repeated testing and/or analysis), it should remain in the preliminary data set. If an outlier resulted from a transcription or similar clerical error, it should be corrected and subsequently reported. Therefore, only if an outlier was associated with problems in the collection or analysis of the samples and as such does not conform with the Guidelines Establishing Test Procedures for the Analysis of Pollutants (40 CFR §136), it can be removed from the data set and not reported on the Discharge Monitoring Report forms (DMRs). Otherwise, all results (including monitoring of pollutants more frequently than required at the location(s) designated, using approved analytical methods as specified in the permit) should be included in the calculation and reporting of the values required in the DMR form. You are encouraged to use "comment" section of the DMR form (or attach additional pages), in order to explain any potential outliers or dubious results.

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

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 9 of 29

PART 11 GENERAL PROVISIONS

A. GENERAL PROVISIONS
1. Duty to Reapply Permittee is not authorized to discharge after the expiration date of this permit. In order to receive authorization to discharge beyond the expiration date, the permittee shall submit such information and forms as are required to the Director of Water Pollution Control (the "Director") no later than 180 days prior to the expiration date. Such applications must be properly signed and certified. 2. Right of Entry The permittee shall allow the Director, the Regional Administrator of the U.S. Environmental Protection Agency, or their authorized representatives, upon the presentation of credentials:

a. To enter upon the permittee's premises where an effluent source is located or where records are required to be kept under the terms and conditions of this permit, and at reasonable times to copy these records;
b. To inspect at reasonable times any monitoring equipment or method or any collection, treatment, pollution management, or discharge facilities required under this permit; and

c. To sample at reasonable times any discharge of pollutants. 3. Availability of Reports Except for data determined to be confidential under Section 308 of the Federal Water Pollution Control Act, as amended, all reports prepared in accordance with the terms of this permit shall be available for public inspection at the offices of the Division of Water Pollution Control. As required by the Federal Act, effluent data shall not be considered confidential. 4. Proper Operation and Maintenance

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

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 10 of 29 b. Dilution water shall not be added to comply with effluent requirements to achieve BCT, BPT, BAT and or other technology-based effluent limitations such as those in State of Tennessee Rule 1200-4-5-.09.
5. Treatment Facility Failure The permittee, in order to maintain compliance with this permit, shall control production, all discharges, or both, upon reduction, loss, or failure of the treatment facility, until the facility is restored or an alternative method of treatment is provided. This requirement applies in such situations as the reduction, loss, or failure of the primary source of power.
6. Property Rights The issuance of this permit does not convey any property rights in either real or personal property, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State, or local laws or regulations.
7. Severability The provisions of this permit are severable. If any provision of this permit due to any circumstance, is held invalid, then the application of such provision to other circumstances and to the remainder of this permit shall not be affected thereby.
8. Other Information If the permittee becomes aware that he failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to the Director, then he shall promptly submit such facts or information.

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

a. The alteration or addition to a permitted facility may meet one of the criteria for determining whether a facility is a new source in 40 CFR 122.29(b); or
b. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged. This notification applies to pollutants which are subject neither to effluent limitations in the permit, nor to notification requirements under 40 CFR 122.42(a)(1). 2. Permit Modification, Revocation, or Termination

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

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 11 of 29 b. The permittee shall furnish to the Director, within a reasonable time, any information which the Director may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit, or to determine compliance with this permit. The permittee shall also furnish to the Director, upon request, copies of records required to be kept by this permit.

c. If any applicable effluent standard or prohibition (including any schedule of compliance specified in such effluent standard or prohibition) is established for any toxic pollutant under Section 307(a) of the Federal Water Pollution Control Act, as amended, the Director shall modify or revoke and reissue the permit to conform to the prohibition or to the effluent standard, providing that the effluent standard is more stringent than the limitation in the permit on the toxic pollutant. The permittee shall comply with these effluent standards or prohibitions within the time provided in the regulations that establish these standards or prohibitions, even if the permit has not yet been modified or revoked and reissued to incorporate the requirement.
d. The filing of a request by the permittee for a modification, revocation, reissuance, termination, or notification of planned changes or anticipated noncompliance does not halt any permit condition. 3. Change of Ownership This permit may be transferred to another party (provided there are neither modifications to the facility or its operations, nor any other changes which might affect the permit limits and conditions contained in the permit) by the permittee if:

a. The permittee notifies the Director of the proposed transfer at least 30 days in advance of the proposed transfer date;
b. The notice includes a written agreement between the existing and new permittees containing a specified date for transfer of permit responsibility, coverage, and liability between them; and

c. The Director, within 30 days, does not notify the current permittee and the new permittee of his intent to modify, revoke or reissue, or terminate the permit and to require that a new application be filed rather than agreeing to the transfer of the permit. Pursuant to the requirements of 40 CFR 122.61, concerning transfer of ownership, the permittee must provide the following information to the division in their formal notice of intent to transfer ownership: 1) the NPDES permit number of the subject permit; 2) the effective date of the proposed transfer; 3) the name and address of the transferor; 4) the name and address of the transferee; 5) the names of the responsible parties for both the transferor and transferee; 6) a statement that the transferee assumes responsibility for the subject NPDES permit; 7) a statement that the transferor relinquishes responsibility for the subject NPDES permit; 8) the signatures of the responsible parties for both the transferor and transferee pursuant to the requirements of 40 CFR 122.22(a), "Signatories to permit applications"; and, 9) a statement regarding any proposed modifications to the facility, its operations, or any other changes which might affect the permit limits and conditions contained in the permit.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 12 of 29 4. Change of Mailing Address The permittee shall promptly provide to the Director written notice of any change of mailing address. In the absence of such notice the original address of the permittee will be assumed to be correct.

C. NONCOMPLIANCE

1. Effect of Noncompliance All discharges shall be consistent with the terms and conditions of this permit. Any permit noncompliance constitutes a violation of applicable State and Federal laws and is grounds for enforcement action, permit termination, permit modification, or denial of permit reissuance.
2. Reporting of Noncompliance

a. 24-Hour Reporting In the case of any noncompliance which could cause a threat to public drinking supplies, or any other discharge which could constitute a threat to human health or the environment, the required notice of non-compliance shall be provided to the Division of Water Pollution Control in the appropriate regional Field Office within 24-hours from the time the permittee becomes aware of the circumstances. (The regional Field Office should be contacted for names and phone numbers of environmental response personnel). A written submission must be provided within five calendar days of the time the permittee becomes aware of the circumstances, unless this requirement is waived by the Director on a case-by-case basis. The permittee shall provide the Director with the following information:
i. A description of the discharge and cause of noncompliance;
ii. The period of noncompliance, including exact dates and times or, if not corrected, the anticipated time the noncompliance is expected to continue; and
ill. The steps being taken to reduce, eliminate, and prevent recurrence of the noncomplying discharge.
b. Scheduled Reporting For instances of noncompliance which are not reported under subparagraph 2.a. above, the permittee shall report the noncompliance on the Discharge Monitoring Report. The report shall contain all information concerning the steps taken, or planned, to reduce, eliminate, and prevent recurrence of the violation and the anticipated time the violation is expected to continue.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 13 of 29 3. Upset

a. "Upset means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation.
b. An upset shall constitute an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the permittee demonstrates, through properly signed, contemporaneous operating logs, or other relevant evidence that: 

## i. An upset occurred and that the permittee can identify the cause(s) of the upset;
ii. The permitted facility was at the time being operated in a prudent and workman-like manner and in compliance with proper operation and maintenance procedures;
iii. The permittee submitted information required under "Reporting of Noncompliance" within 24-hours of becoming aware of the upset (if this information is provided orally, a written submission must be provided within five days); and
iv. The permittee complied with any remedial measures required under "Adverse Impact." 4. Adverse Impact The permittee shall take all reasonable steps to minimize any adverse impact to the waters of Tennessee resulting from noncompliance with this permit, including such accelerated or additional monitoring as necessary to determine the nature and impact of the noncomplying discharge. It shall not be a defense for the permittee in an enforcement action that it would have been necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit. 5. Bypass

a. "Bypass" is the intentional diversion of wastewater away from any portion of a treatment facility. "Severe property damage" means substantial physical damage to property, damage to the treatment facilities, which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production.
b. Bypasses are prohibited unless the following 3 conditions are met: 

## i. The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage;

### May 2011 TVA-Bull Run Fossil Plant MODIFICATION to NPDES Permit TN0005410 Page 14 of 29 There are not feasible alternatives to bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment down-time. This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass, which occurred during normal periods of equipment down-time or preventative maintenance; 

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

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

a. For domestic wastewater plants only, a "washout" shall be defined as loss of Mixed Liquor Suspended Solids (MLSS) of 30.00% or more. This refers to the MLSS in the aeration basin(s) only. This does not include MLSS decrease due to solids wasting to the sludge disposal system. A washout can be caused by improper operation or from peak flows due to infiltration and inflow.
b. A washout is prohibited. If a washout occurs the permittee must report the incident to the Division of Water Pollution Control in the appropriate regional Field Office within 24-hours by telephone. A written submission must be provided within 5 days. The washout must be noted on the discharge monitoring report. Each day of a washout is a separate violation.

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

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 15 of 29 2. Liability Under State Law Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties established pursuant to any applicable State law or the Federal Water Pollution Control Act, as amended.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 16 of 29 PART III OTHER REQUIREMENTS

A. ASH POND CLOSURE PLAN The permittee shall submit an Ash Pond Closure Plan describing the steps to be taken to prevent contamination of surface waters from the inactive site. Within 90 days after the permit effective date, the permittee shall define closure actions to be implemented in conjunction with conversion from wet ash to dry ash handling and discontinued operation of existing ash ponds. The permittee will provide quarterly updates on progress toward dry ash conversions and ash pond closure with the Discharge Monitoring Reports submitted for March, June, September, and December. The report must address, at a minimum, the estimated future date for complete closure and elimination of ash pond discharges as well as updated information on planning, design, and construction milestones for each upcoming quarter.

B. DIKE INSPECTIONS 

## MODIFIED MAY 13, 2011 (1) The Bull Run Fossil ash pond shall be inspected in accordance with TVA's Reservoir Operations Dam Safety Program criteria and processes. This program is directed by TVA's Dam Safety Governance Program and is in accordance with the 'Federal Guidelines for Dam Safety' developed by the Federal Emergency Management Agency (FEMA 93). This document directs TVA to perform inspections scheduled on specific intervals and with qualified personnel. The dikes will also be visually inspected daily during operations by site personnel or designee that are trained in dam safety procedures by TVA's Dam Safety Governance Program. Impoundments shall be inspected annually by a state-registered professional engineer trained and experienced in dam safety inspection procedures. Special inspections by qualified personnel shall be done within 24 hours after intense, large or extended rain events (i.e., 10-year storm or equaling or exceeding the design requirements for managing storm water) or as soon as safely practicable after a significant seismic event approaching or exceeding the design event. The reason for this is to validate structural integrity of the structure following an event that could test the design assumptions. (2) Daily inspections shall, at a minimum, include observations of dams, dikes and toe areas for erosion, cracks or bulges, subsidence, seepage, wet or soft soil, changes in geometry, the depth and elevation of the impounded water, sediment or slurry, freeboard, changes in vegetation such as overly lush, obstructive vegetation and trees, outlet controls, drains and any other changes which may indicate a potential compromise to impoundment integrity. TVA must prepare a checklist in accordance with proper TVA Dam Safety Governance Program requirements with review and written concurrence from staff responsible for TVA dam safety. T he checklist must have space for observation notes to be used by the daily inspectors to ensure comprehensive and consistent inspections. Copies of the daily inspection checklist must be maintained in accordance with the recordkeeping requirements specified below. (3) Annual and special inspections shall include the minimum observations set forth in (2). In addition these annual and special inspections must also include a review of daily inspection records, operation and maintenance history, instrumentation design and construction. TheTVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 17 of 29 findings of each inspection along with the specific qualifications of the inspector shall be summarized and documented in the annual report. The permittee shall submit the first annual report no later than 18 months after the effective date of the permit. (4) Remediation Measures. Within 24 hours of discovering changes that indicate a potential compromise to the structural integrity of the impoundment, the permittee shall begin procedures to remediate the problem. Changes such as significant increases in seepage or seepage carrying sediment may be signs of imminent impoundment failure and should be addressed immediately. Other issues which may have long term impacts on integrity, such as trees growing on the embankment (especially large, dead or tilting trees, with special concern for those at the toes of or within the saturated zones of embankment structures), or vegetation-blocking overflows or spillways, shall be removed according to approved geotechnical engineering practices and instructions. 2. Reporting and Recordkeeping Requirements for Impoundments (1) Imminent impoundment failure conditions should be reported immediately to TDEC and the Anderson County Emergency Management Agency, who will report to TEMA. (2) Within 24 hours of discovering a change in the impoundment that indicates a potential compromise to the structural integrity of the dike (e.g., significant changes in seeps, boils, bulges, or cracks), the permittee must make contact with division personnel describing the findings of the inspection, corrective measures taken or proposed (if known), and expected outcomes. TVA must keep current a list of division personnel complete with after-hours contact information and must speak directly to someone on this list within the 24 hour period. Failure to notify the division within 24 hours will be a violation of this permit. In addition, the permittee must submit a follow-up report within 5 days summarizing the incident, corrective actions taken and outcomes. Additional reports pertaining to the event may be required by the Director. (3) The permittee shall submit an annual report to the division summarizing findings of all monitoring activities and measurements, inspections, and remediation measures pertaining to the structural integrity, design, construction, and operation and maintenance of all impoundments. (4) The permittee shall maintain records of all impoundment inspection and maintenance activities, including corrective actions made in response to inspections and all other activities undertaken to repair or maintain the impoundment. The permittee shall also maintain records of any measurements and evaluation of safety factors. All records shall be kept on site and made available to State or Federal inspectors upon request. (5) All pertinent impoundment permits, design, construction, operation, and maintenance information, including but not limited to: records of the training provided to the daily inspectors, plans, geotechnical and structural integrity studies, copies of permits, associated certifications by qualified, State-registered professional engineer, and regulatory approvals, shall be kept on site and made available to State or Federal inspectors upon request.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 18 of 29

(6) Permit Re-opener Requirement The Director may re-open this permit to incorporate more stringent requirements or any applicable standards pertaining to the operation and maintenance of coal combustion waste impoundments.

C. TOXIC POLLUTANTS The permittee shall notify the Division of Water Pollution Control as soon as it knows or has reason to believe:
1. That any activity has occurred or will occur which would result in the discharge on a routine or frequent basis, of any toxic substance(s) (listed at 40 CFR 122, Appendix D, Table II and III) which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels":

a. One hundred micrograms per liter (100 ug/l);
b. Two hundred micrograms per liter (200 ug/I) for acrolein and acrylonitrile; fivehundred micrograms per liter (500 ug/I) for 2,4-dinitrophenol and for 2-methyl4,6-dinitrophenol; and one milligram per liter (1 mg/L) for antimony;

c. Five (5) times the maximum concentration value reported for that pollutant(s) in the permit application in accordance with 122.21(g)(7); or
d. The level established by the Director in accordance with 122.44(f).
2. That any activity has occurred or will occur which would result in any discharge, on a non-routine or infrequent basis, of a toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels":

a. Five hundred micrograms per liter (500 ugA);
b. One milligram per liter (1 mg/L) for antimony;

c. Ten (10) times the maximum concentration value reported for that pollutant in the permit application in accordance with 122.21(g)(7); or
d. The level established by the Director in accordance with 122.44(f).

D. HEAVY METALS MONITORING

The permittee shall monitor heavy metals at the West Knox District Intake on semi-annual basis to ensure this source will not exceed Drinking Water Standards. Heavy metals shall not be discharged in concentrations which cause intake concentrations in the West Knox Utility District Intake to exceed the limitations for the drinking water supply classification under Rule 1200-4-3. The permittee shall certify annually that the required intake

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 19 of 29 concentrations are maintained and shall submit the report to the Division with the monthly DMR once per year.

E. REOPENER CLAUSE If an applicable standard or limitation is promulgated under Sections 301(b)(2)(C) and (D), 304(6)(2), and 307(a)(2) and that effluent standard or limitation is more stringent than any effluent limitation in the permit or controls a pollutant not limited in the permit, the permit shall be promptly modified or revoked and reissued to conform to that effluent standard or limitation.

E. PLACEMENT OF PUBLIC NOTIFICATION SIGNS Within sixty (60) days of the effective date of this permit, the permittee shall place and maintain a sign(s) at each outfall and any bypass/overflow point in the collection system. For the purposes of this requirement, any bypass/overflow point that has discharged five (5) or more times in the last year must be so posted. The sign(s) should be clearly visible to the public from the bank and the receiving stream or from the nearest public property/right-of-way, if applicable. The minimum sign size should be two feet by two feet (2' x 2') with one inch (1") letters. The sign should be made of durable material and have a white background with black letters. The sign(s) are to provide notice to the public as to the nature of the discharge and, in the case of the permitted outfalls, that the discharge is regulated by the Tennessee Department of Environment and Conservation, Division of Water Pollution Control. The following is given as an example of the minimal amount of information that must be included on the sign:
TREATED INDUSTRIAL WASTEWATER — OUTFALL ### TVA Bull Run Fossil Plant (BRF) (Permittee's Phone Number) NPDES Permit NO, TN0005410 TENNESSEE DIVISION OF WATER POLLUTION CONTROL 1-888-891-8332 ENVIRONMENTAL FIELD OFFICE - Knoxville

F. ANTIDEGRADATION Pursuant to the Rules of the Tennessee Department of Environment and Conservation, Chapter 1200-4-3-.06, titled "Tennessee Antidegradation Statement," and in consideration of the Department's directive in attaining the greatest degree of effluent reduction achievable in municipal, industrial, and other wastes, the permittee shall further be required, pursuant to the terms and conditions of this permit, to comply with the effluent limitations and schedules of compliance required to implement applicable water quality standards, to comply with a State Water Quality Plan or other State or Federal laws or regulations, or where practicable, to comply with a standard permitting no discharge of pollutants.

G. BIOMONITORING REQUIREMENTS, CHRONIC

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 20 of 29 The permittee shall conduct a 3-Brood Ceriodaphnia dubia Survival and Reproduction Test and a 7-Day Fathead Minnow (Pimephales promelas) Larval Survival and Growth Test on the same samples of final effluent from Outfall 001 once durincithe permit period during the permit period and Outfall 002 annually (only when biocides are used). The measured endpoint for toxicity will be the inhibition concentration causing 25% reduction (IC25) in survival, reproduction, or growth of the test organisms. The IC25 shall be determined based on a 25% reduction as compared to the controls. The average reproduction and growth responses will be determined based on the number of Ceriodaphnia dubia or Pimephales promelas larvae used to initiate the test. A separate statistical analysis based on survival information is not required. Test shall be conducted and its results reported based on appropriate replicates of a total of five serial dilutions and a control, using the percent effluent dilutions as presented in the following tables:
Outfall 001 Serial Dilutions for Whole Effluent Toxicity (WET) Testing 4 X IWC 2 X

IWC Instream

Wastewater Concentration (IWC) 0.5 X

IWC 0.25 X

IWC Control

% effluent 58.9 29.4 14.7 7.4 I 3.7 0

Outfall 002 Serial Dilutions for Whole Effluent Toxicity (WET) Testing Permit Limit (P L) 0.50 X PL 0.25 X PL 0.125 X PL 0.0625 X PL Control
% effluent 100 50 25 12.5 6.25 0
The dilution/control water used will be a moderately hard water as described in ShortTerm Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013 (or the most current edition). Results from a chronic standard reference toxicant quality assurance test for each species tested shall be submitted with the discharge monitoring report. Reference toxicant tests shall be conducted as requiredin EPA-821-R-02-013 (or the most current edition). Additionally, the analysis of this multiconcentration test shall include review of the concentration-response relationship to ensure that calculated test results are interpreted appropriately. Toxicity will be demonstrated if the IC25 is less than or equal to the permit limit indicated for each outfall in the above table(s). When effluent toxicity is demonstrated and ambient

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 21 of 29 samples run concurrently with the effluent test are also shown to be toxic enough to represent a test failure (100 percent samples statistically less than controls using t-tests and minnow growth or daphnid reproduction is 25 percent less than controls), the test will be repeated and no permit violation will be issued. Effluent toxicity demonstrated by the tests specified herein which is not shown to be related to ambient conditions constitutes a violation of this permit. All tests will be conducted using a minimum of three 24-hour flow-proportionate composite samples of final effluent (e.g., collected on days 1, 3 and 5). If, in any control more than 20% of the test organisms die in 7 days, the test (control and effluent) is considered invalid and the test shall be repeated within 30 days of the date the initial test is invalidated. Furthermore, if the results do not meet the acceptability criteria as defined in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and MarineOrganisms, EPA-821-R-02-013 (or the most current edition), or if the required concentrationresponse review fails to yield a valid relationship per guidance contained in Method Guidance and Recommendations for Whole Effluent Toxicity (WET) Testing, EPA-821-B-00-004 (or the most current edition), that test shall be repeated. Any test initiated but terminated before completion must also be reported along with a complete explanation for the termination. For Outfall 001, the toxicity tests specified herein shall be conducted once during the final 18 months of the new permit term and the results of these tests submitted with the next permit application. The toxicity tests at Outfall 002 specified herein shall commence no later than 90 days from biocide application. If no biocides are added, Outfall 002 discharges consist of raw river water to which no chemicals are added. Future requirements may be added as a Biocide / Chemical Treatment Plan (B/CTP) is developed In the event of a test failure, the permittee must start a follow-up test within 2 weeks and submit results from a follow-up test within 30 days from obtaining initial WET testing results. The follow-up test must be conducted using the same serial dilutions as presented in the corresponding table(s) above. The follow-up test will not negate an initial failed test. In addition, the failure of a follow-up test will constitute a separate permit violation which must also be reported. In the event of 2 consecutive test failures or 3 test failures within a 12 month period for the same outfall, the permittee must initiate a Toxicity Identification Evaluation/Toxicity Reduction Evaluation (TIE/TRE) study within 30 days and so notify the division by letter. This notification shall include a schedule of activities for the initial investigation of that outfall. During the term of the TIE/TRE study, the frequency of biomonitoring shall be once every three months. Additionally, the permittee shall submit progress reports once every three months throughout the term of the TIE/TRE study. The toxicity must be reduced to allowable limits for that outfall within 2 years of initiation of the TIE/TRE study. Subsequent to the results obtained from the TIE/TRE studies, the permittee may request an extension of the TIE/TRE study period if necessary to conduct further analyses. The final determination of any extension period will be made at the discretion of the division. The TIE/TRE study may be terminated at any time upon the completion and submission of 2 consecutive tests (for the same outfall) demonstrating compliance. Following the completion of TIE/TRE study, the frequency of monitoring will return to a regular schedule, as defined previously in this section as well in Part I of the permit. During the course of the TIE/TRE study, the permittee will continue to conduct toxicity testing of the outfall being investigated at the frequency of once every three months but will not be required to perform follow-up tests for that outfall during the period of TIE/TRE study.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 22 of 29
Test procedures, quality assurance practices, determinations of effluent survival/reproduction and survival/growth values, and report formats will be made in accordance with Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013, or the most current edition. Results of all tests, reference toxicant information, copies of raw data sheets, statistical analysis and chemical analyses shall be compiled in a report. The report will be written in accordance with Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013, or the most current edition. Two copies of biomonitoring reports (including follow-up reports) shall be submitted to the division. One copy of the report shall be submitted along with the discharge monitoring report (DMR). The second copy shall be submitted to the local Division of Water Pollution Control office address: Environmental Field Office- Knoxville Division of Water Pollution Control 3711 Middlebrook Pike, Suite 220 Knoxville, TN 37921-8332

G. MACROINVERTEBRATE CONTROL MEASURES - BIOCIDE/CORROSION TREATMENT PLAN (B/CTP) Previous permits addressed "toxic chemicals", biocide(s), and slimicide(s) use at the site for process and non-process flows in a Best Management Plan (BMP) program. A new program for managing the use of these products shall be developed under a Biocide/Corrosion Treatment Plan (B/CTP). This plan is similar to other major-classed TVA facilities in Tennessee. The B/CTP shall describe chemical applications and macroinvertebrate controls; include all material feed rates, and proposed monitoring schedule(s) to verify that effluent limitations are being met and water quality is being protected. The permittee shall conduct treatments of intake or process waters under this permit using biocides, dispersants, surfactants, corrosion inhibiting chemicals, or detoxification chemicals in accordance with conditions approved and specified in the previous permit for a period of no more that 8-months after the effective date of the permit to allow time for TVA to create the B/CTP and also allow time for the division to review and approve the B/CTP. At that later date, Whole Effluent Toxicity testing (WET) frequency and results reporting will be governed by the B/CTP. The permittee shall maintain the [new] B/CTP plan at the facility and make the plan available to the permit issuing authority upon request. The permittee shall amend the B/CTP plan whenever there is a change in the application of the chemical additives or change in the operation of the facility that materially increases the potential for these activities to result in a discharge of significant amounts of pollutants. The division shall also be notified in writing within 30-days of any material-vendor changes that will change the names or Quantities used of any such chemical additives.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 23 of 29 H. RE-ROUTING FLOWS FOR MAINTENANCE PURPOSES The permittee shall be allowed to re-route flows past normal monitoring points as a temporary measure for maintenance activities. However, such re-routing must be done in such a way that permit limitations are still being met in the receiving waters and compliance with permit limitations is monitored and reported on the DMR's for the re-routed flows. The receiving waters must be the same for the re-routed flows as for the normal discharges.

I. FACILITY INTAKE WATER QUALITY MONITORING REQUIREMENTS The permittee shall annually monitor the facility intake water for the following effluent characteristics (in mg/1): Hardness (as CaCO 3 ), TSS, Aluminum, Antimony, Arsenic, Cadmium, Chromium, Copper, Iron, Lead, Manganese, Mercury, Nickel, Selenium, Silver, Zinc, and Cyanide. All metals shall be reported as Total Recoverable Metal. All samples reported as "Below Detection Level" shall be analyzed to the Required Detection Level (RDL) specified in Tennessee General Water Quality Criteria, Chapter 1200-4-3-.05(8) except for Mercury which shall be analyzed by EPA Method 1631 or 245.7. Two copies of the monitoring results shall be submitted with the Discharge Monitoring Report in the month following sample collection.

J. ALTERNATE THERMAL LIMITATION, SECTION 316(A) OF THE CWA 316(a) alternate thermal variance remains in effect for the duration of the permit cycle. For more detail, refer to the rationale portion of this permit and Title 40, Code of Federal Regulations, §125.73 "Criteria and standards for the determination of iterative effluent limitations under section 316(a)". Within 60 days of the permit effective date, the permittee shall prepare and submit for review by the Division and EPA Region 4 a study plan which outlines how the permittee will conduct assessments that will generate information sufficient to support a determination of whether the Bull Run Plant's alternative thermal limit under Section 316(a) can be continued in its next NPDES permit. The proposed study plan shall be designed to supplement information previously provided by the permittee. The permittee shall implement provisions of the plan within 60 days of its approval by the Division.

K. COOLING WATER INTAKE STRUCTURES - PHASE II, SECTION 316(B) OF THE CWA
316(b) limitations for this facility are determined to be in compliance based on best professional judgment in accordance with 40 CFR 401.14 and 122.43. This permit may be reopened to address compliance with the Rule (316(b)) requirements upon reissuance of a new rule or final guidance by the U.S. Environmental Protection Agency (U.S. EPA).

L. AMMONIA NITROGEN, TOTAL
Selective Non-Catalytic Reduction (SNCR) equipment is used at BRF to lower nitrogen oxide stack emissions, as mandated by the Tennessee Air Quality Board. Installation and

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 24 of 29 operation of the equipment, which involves injection of ammonia nitrogen into the process, has been underway prior to the previous permit. Wastewater volume of 18.7 MGD discharged from Outfall 001 in this application is only marginally different from the previous permit of 17 MGD. Although the potential exists for effluent discharged from this outfall to contain increased amounts of ammonia nitrogen, reported concentrations of intake and effluent do not show substantial differences of 0.1 mg/I and 0.2 mg/I, respectively. To assess the potential for ammonia toxicity in the receiving stream, TDEC uses a spreadsheet calculation which considers stream pH and temperature, as shown below. These calculations indicate the allowable effluent concentration of 11 mg/I would be required to protect water quality. Accordingly, the renewed permit shall continue monitoring only at Outfall 001 for ammonia. Monitoring, on a report basis, will include inflow (sampled at the skimmer wall or at a comparable location) and effluent from Outfall 001. The net discharge will be calculated and reported. If a calculated value for net addition of ammonia as nitrogen exceeds an action concentration value of 0.45 mg/L, the permittee shall investigate source(s) of ammonia, and proceed with a corrective action(s), if necessary. Furthermore, EFO - Knoxville shall be notified within 24 hours from the time the permittee receives results indicating that an action value of 1.0 mg/L was exceeded. Monitoring will be performed on a monthly basis, using grab samples.

M. EMERGENCY RESPONSE PLAN For purposes of this NPDES permit, TVA Bull Run Fossil Plant must develop an Emergency Response Plan which addresses the TDEC Advisory Board Lessons Learned, 2009: "a preparedness plan that consider[s] a boundary for potentially affected topographic features based on mud flow and wave propagation to develop requirements for CCW storage that will minimize any life threatening effects due to failure."

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 25 of 29

PART IV BEST MANAGEMENT PRACTICES Best Management Practices (BMPs) are incorporated as permit conditions to specifically address controls on toxic metals in ash pond discharges. These controls can be site-specific to BRF operations and practices to address the circumstances of individual fossil plants. Each practice must be developed and measured to document the relationship between operations and effluent metals concentrations. BMPs should be established based on guidance shown in Attachment 1 with submission of a BMP Plan for division review within 90 days following the permit Effective Date.
PART V STORM WATER POLLUTION PREVENTION PLAN Storm water runoff at the BRF plant that is not discharged through Outfalls 001 and 002 via the ash pond is authorized under the Tennessee Storm Water Multi-Sector General Permit for Industrial Activities (TMSP), Permit Number TNR053185. The Plant shall maintain the existing approved storm water pollution prevention plan (SWPPP) pursuant to the requirements as set forth in the Tennessee Multi-Sector General Permit for Industrial Activities, Sector 0: "Storm Water Discharges Associated With Industrial Activity From Steam Electric Power Generating Facilities", and Sector L: "Storm Water Discharges Associated With Industrial Activity From Landfills and Land Application Sites."

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 26 of 29

PART VI Definitions and Acronyms

DEFINITIONS

For the purpose of this permit, "annually" is defined as a monitoring frequency of once every twelve (12) months beginning with the date of issuance of this permit so long as the following set of measurements for a given 12 month period are made approximately 12 months subsequent to that time.
A "bypass" is defined as the intentional diversion of waste streams from any portion of a treatment facility.
A "calendar day' is defined as the 24-hour period from midnight to midnight or any other 24-hour period that reasonably approximates the midnight to midnight time period.
A "composite sample", in general is a sample collected continuously over a period of 24-hours at a rate proportional to the flow. Composite sample should be a combination of at least 8 sample aliquots of at least 100 milliliters, collected at periodic intervals during the operating hours of a facility over a 24- hour period.
The "daily maximum amount", is a limitation measured in pounds per day (1b/clay), on the total amount of any pollutant in the discharge by weight during any calendar day.
The "daily maximum concentration" is a limitation on the average concentration in units of mass pervolume (e.g. milligrams per liter), of the discharge during any calendar day. When a proportional-toflow composite sampling device is used, the daily concentration is the concentration of that 24-hour composite; when other sampling means are used, the daily concentration is the arithmetic mean of the concentrations of equal volume samples collected during any calendar day or sampling period. "Degradation" means the alteration of the properties of waters by the addition of pollutants or removal of habitat. "Discharge" or "discharge of a pollutant" refers to the addition of pollutants to waters from a source.
A "dry weather overflow" is a type of sanitary sewer overflow and is defined as one day or any portion of a day in which unpermitted discharge of wastewater from the collection or treatment system other than through the permitted outfall occurs and is not directly related to a rainfall event. Discharges from more than one point within a 24-hour period shall be counted as separate overflows.
An "ecoregion" is a relatively homogeneous area defined by similarity of climate, landform, soil, potential natural vegetation, hydrology, or other ecologically relevant variables.
The "geometric mean" of any set of values is the n th root of the product of the individual values where "n" is equal to the number of individual values. The geometric mean is equivalent to the antilog of the arithmetic mean of the logarithms of the individual values. For the purposes of calculating the geometric mean, values of zero (0) shall be considered to be one (1).
A "grab sample", for the purposes of this permit, is defined as a single effluent sample of at least 100 milliliters (sample volumes <100 milliliters are allowed when specified per standard methods, latest edition) collected at a randomly selected time over a period not exceeding 15 minutes. The sample(s) shall be collected at the period(s) most representative of the total discharge.

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 27 of 29 The "instantaneous maximum concentration" is a limitation on the concentration, in milligrams per liter, of any pollutant contained in the wastewater discharge determined from a grab sample taken from the discharge at any point in time.
The "instantaneous minimum concentration" is the minimum allowable concentration, in milligrams per liter, of a pollutant parameter contained in the wastewater discharge determined from a grab sample taken from the discharge at any point in time.
The "monthly average amount', is a discharge limitation measured in pounds per day (lb/day), is the total amount of any pollutant in the discharge by weight during a calendar month divided by the number of days in the month that the production or commercial facility was operating. Where less than daily sampling is required by a permit, the monthly average amount shall be determined by the summation of all the measured daily discharges by weight divided by the number of days during the calendar month when the measurements were made. For the purpose of this definition, a frequency of 2/Month is representative of 2 separate daily samples, each sample having been collected on a separate day during the monitoring period.
The "monthly average concentration", other than for E. coil bacteria, is a limitation on the discharge concentration, in milligrams per liter (mg/L), and is the arithmetic mean of all daily concentrations determined in a one calendar month period. For the purpose of this definition, a frequency of 2/Month is representative of 2 separate daily samples, each sample having been collected on a separate day during the monitoring period.
A "one week period' (or "calendar-week') is defined as the period from Sunday through Saturday. For reporting purposes, a calendar week that contains a change of month shall be considered part of the latter month.
"Pollutant' means sewage, industrial wastes, or other wastes.
A "quarter" is defined as any one of the following three-month periods: January 1 through March 31, April 1 through June 30, July 1 through September 30, and/or October 1 through December 31.
A "rainfall event' is defined as any occurrence of rain, preceded by 10 hours without precipitation that results in an accumulation of 0.01 inches or more. Instances of rainfall occurring within 10 hours of each other will be considered a single rainfall event.
A "rationale" {or "fact sheet") is a document that is prepared when drafting an NPDES permit or permit action. It provides the technical, regulatory and administrative basis for an agency's permit decision.
A "reference site

, ' means least impacted waters within an ecoregion that have been monitored to establish a baseline to which alterations of other waters can be compared.
A "reference condition" is a parameter-specific set of data from regional reference sites that establish the statistical range of values for that particular substance at least-impacted streams.
A "sanitary sewer overflow (SSO)" is defined as an unpermitted discharge of wastewater from the collection or treatment system other than through the permitted outfall. For the purpose of this permit, "semi-annually" means the same as "once every six months." Measurements of the effluent characteristics concentrations may be made anytime during a 6 month period beginning from the issuance date of this permit so long as the second set of measurements for a given 12 month period are made approximately 6 months subsequent to that time, if feasible. "Sewage" means water-carried waste or discharges from human beings or animals, from residences, public or private buildings, or industrial establishments, or boats, together with such other wastes and ground, surface, storm, or other water as may be present. "Severe property damage" when used to consider the allowance of a bypass or SSO means substantial physical damage to property, damage to the treatment facilities which causes them to

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 28 of 29 become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass or SSO. Severe property damage does not mean economic loss caused by delays in production. "Sewerage system" means the conduits, sewers, and all devices and appurtenances by means of which sewage and other waste is collected, pumped, treated, or disposed.
A "subecoregiori' is a smaller, more homogenous area that has been delineated within an ecoregion. "Upset' means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. The term, "washout' is applicable to activated sludge plants and is defined as loss of mixed liquor suspended solids (MLSS) of 30.00% or more from the aeration basin(s).
"Waters" means any and all water, public or private, on or beneath the surface of the ground, which are contained within, flow through, or border upon Tennessee or any portion thereof except those bodies of water confined to and retained within the limits of private property in single ownership which do not combine or effect a junction with natural surface or underground waters.
The "weekly average amount", shall be determined by the summation of all the measured daily discharges by weight divided by the number of days during the calendar week when the measurements were made.
The "weekly average concentration', is the arithmetic mean of all the composite samples collected in a one-week period. The permittee must report the highest weekly average in the one-month period. "Wet Weather Flow" shall be construed to represent storm water runoff which, in combination with all process and/or non-process wastewater discharges, as applicable, is discharged during a qualifying storm event.

A "qualifying storm event" is one which is greater than 0.1 inches and that occurs after a period of at least 72 hours after any previous storm event with rainfall of 0.1 inches or greater.

ACRONYMNS AND ABBREVIATIONS

1Q10 — 1-day minimum, 10-year recurrence interval 30020 — 30-day minimum, 20-year recurrence interval 7Q10 — 7-day minimum, 10-year recurrence interval BAT — best available technology economically achievable BCT — best conventional pollutant control technology BDL — below detection level BOD 5 — five day biochemical oxygen demand BPT — best practicable control technology currently available CBOD 5 — five day carbonaceous biochemical oxygen demand CEI — compliance evaluation inspection CFR — code of federal regulations CFS — cubic feet per second CFU — colony forming units CIU — categorical industrial user

### TVA-Bull Run Fossil Plant

May 2011 MODIFICATION to NPDES Permit TN0005410 Page 29 of 29 CSO — combined sewer overflow CWA — Clean Water Act DMR — discharge monitoring report D.O. — dissolved oxygen E. coil — Escherichia coil EFO — environmental field office LB(Ib) - pound IC25 — inhibition concentration causing 25% reduction in survival, reproduction and growth of the test organisms IU industrial user IWS — industrial waste survey LC 5 0 — acute test causing 50% lethality MDL — method detection level MGD — million gallons per day MG/L(mg/1) — milligrams per liter ML — minimum level of quantification ml — milliliter MLSS — mixed liquor suspended solids MOR — monthly operating report NODI — no discharge NOEC — no observed effect concentration NPDES — national pollutant discharge elimination system PL — permit limit POTW — publicly owned treatment works RDL — required detection limit SAR — semi-annual [pretreatment program] report SIU — significant industrial user SSO — sanitary sewer overflow STP — sewage treatment plant TCA — Tennessee code annotated TDEC — Tennessee Department of Environment and Conservation TIETTRE — toxicity identification evaluation/toxicity reduction evaluation TMDL — total maximum daily load TRC — total residual chlorine TSS — total suspended solids WQBEL — water quality based effluent limit

### TVA-Bull Run Fossil Plant

May 2011 Rationale - MODIFICATION to NPDES Permit TN0005410 Page R- 1 of R-1 

## RATIONALE FOR MODIFICATION, MAY 2011 TVA - Bull Run Fossil Plant (BRF) NPDES PERMIT NO. TN0005410 Bull Run, Anderson County, Tennessee
Permit Writer: Mr. Bob Alexander

1. Revision to Dike Inspection Language Minor revisions are made to clarify training and recordkeeping procedures by facility personnel in relation to the TVA Dam Safety Program. Specifically, the revisions require use of a checklist for inspections which is based upon the TVA Dam Safety Program.

2. TVA requests Adding notation to Outfall 004 description to include building sump added to intake screen backwash: TDEC concurs, since this does not change the permit approach that the backwash should not contain anything that is not already present in the river and found in the intake.
3. Clarification of Outfall 005 Chemical Pond Monitoring Provisions during Pond Closure: The NPDES Permit issued in September 2010 required submission of an Ash Pond Closure Plan, received in January 2011. Closure of the Chemical Pond, Outfall 005 is one of the first closure projects to be addressed. TVA has proposed monitoring provisions for the ash pond discharge at Outfall 001 which will include the dewatering of the chemical pond. These provisions include the same metals — copper and iron — plus TSS, Oil and Grease as required by EPA effluent guidelines. TDEC concurs with the proposed monitoring at Outfall 001 during the Chemical Pond closure.
4. Deleting the Ash Pond Free Water Volume (FWV) requirement from Outfall 001: Since the permit provision is based on a 1985 EPA memorandum which preceded the Effluent Guidelines of 1988, the inclusion of an FWV requirement is subject to the permit writer's discretion. The BRF permit stipulates an effluent TSS concentration based upon the ELGs and it remains in effect. The several BMPs used by TVA to maintain compliance with effluent TSS are working. Because TVA has committed to dry ash conversion at BRF and other plants, the operation and available FWV will be a dynamic process which can cause unnecessary effort both by TVA and TDEC in reporting this administrative FWV provision. Since the ultimate measure of ash pond effectiveness is the TSS effluent concentration, TDEC concurs in the deletion of the FWV requirement.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 1 of NOD - 41 NOTICE OF DETERMINATION August 2010

With Record of Comments on Draft Permit and TDEC Responses
National Pollutant Discharge Elimination System TVA Bull Run Fossil Plant, Clinton, TN NPDES Permit No. TN0005410 August 30, 2010
I. Summary On August 25, 2007, the Tennessee Valley Authority (TVA) submitted an application for an NPDES Permit for the discharge of effluent from the combined bottom ash- gypsum settling pond at the Bull Run Fossil Plant (BRF) in Clinton, TN. The TN Department of Environment and Conservation (TDEC), Division of Water Pollution Control (the division) published a draft permit TN0005410 for the facility on January 25, 2010. Also, the division issued a public notice on the availability of the draft permit for public review and for a public hearing to be held in Oak Ridge, TN. The hearing was held on March 2, 2010, and was followed by a comment period through April 12, 2010. This Notice of Determination addresses comments presented at the hearing and submitted during the public notice period. It also presents TDEC's decision regarding the permit and rationale for that decision. Comments are shown below with TDECs response and proposed permit changes, as applicable. Written comments are, for the most part, shown verbatim. Lengthy comments have been paraphrased from multiple-page comments which included background and spreadsheets of data. The full length documents are available for review on request. Verbal comments from the April 10, 2010 public hearing are paraphrased. Comments are shown in plain text with responses shown in bold text.

II. TVA Coal Byproduct Process Conversion TDEC recognizes that the TVA's Board of Directors decided on August 20 th , 2009, to convert wetfly-ash and bottom ash handling systems to dry-ash handling systems at six of TVA's eleven coalburning plants. The decision also included converting gypsum dewatering facilities and closing ash and gypsum ponds. Pending development of new measures based on the TVA Board decision, the NPDES permit provisions will remain in effect. BRF is one of the six facilities scheduled for the conversion.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 2 of NOD - 41 Ill. Administrative Record The permit rationale (or fact sheet) dated January, 2010, sets forth the division's basis for permit conditions to be applied for the issuance of the Tennessee NPDES permit for the facility discharges. The permit authorizes point source discharges to waters of the State of Tennessee from the facility. On January 25, 2010, the division issued Public Hearing Notice PH10-03, which announced a public hearing, conducted on Tuesday, March 2, 2010, at 6 p.m. (EDT). On January 25, 2010, the division issued Public Notice #MMIX-002, which announced its intent to issue the permit. The draft permit was made available in an electronic format on the division's web site at http://www.state.tn.usienvironment/wpc/wpcppo/ . The NPDES permit was drafted in accordance with the provisions of the Federal Water Pollution Control Act, the Tennessee Water Quality Control Act, and other applicable standards and regulations. At the request of Environmental Integrity Project and other groups, the division received comments through April 12, 2010. This Notice of Determination (NOD) serves as the division's response to questions, comments and issues that were raised at the hearing and/or submitted during the subsequent comment period.

IV. Facility Description BRF discharges approximately 19 MGD from a retention pond into the Clinch River at mile 46.3 viathe plant discharge channel. BRF discharges consist of ash transport water, chemical and nonchemical metal cleaning wastewaters, coal pile runoff, low volume wastes, storm water runoff, miscellaneous equipment cooling and lubricating water from Outfall 001 and Outfall 006 (emergency overflow), main condenser cooling water, miscellaneous equipment cooling and lubricating water and sewage treatment plant effluent from Outfall 002, intake screen backwash water through Out

- fall 004, and metal cleaning waste water through Outfall 005 to Clinch River at mile 48.0. Discharged wastewater originates from the process of generation of electric power from a fossil-fueled steam-electric plant. The plant has one coal-fired unit with a generating capacity of 950 megawatts.
V. Permit History Permit was last modified in November, 2007, and expired on March 30, 2008 with an administrative extension for current coverage of daily operations at the Bull Run Fossil Plant.
VI. Public Review Comments and Responses Commenters suggested changes to the previous rationale and addendum to rationale. The rationale portion of a permit is not edited after public notice has occurred. The rationale is not legally binding. Note that suggested changes were made to the cover page describing the authorized discharges. Comments suggesting changes to the permit of a grammatical, typographical, and informational nature are made in the final permit, but are not repeated herein.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 3 of NOD - 41 Comment 1: Permit title page and page 1 of 25 descriptions of Outfalls: the description of Outfalls on the title page and on page 1 of 25 should match the flow diagram included with the permit application.
RESPONSE: Revisions were made in the permit.

Comment 2: Revised monitoring frequencies were requested based on the reported concentrations being much lower than calculated effluent concentrations deemed necessary to protect water quality. Requested revisions include: • arsenic, low level mercury, and thallium be reduced from monthly to quarterly; • cadmium, chromium, copper, lead, nickel, selenium, silver, and zinc be reduced from monthly to annually; • IC25 be changed from annually to once during the permit term. RESPONSE: TDEC will retain proposed monthly monitoring frequency for toxic metals for a period of twelve (12) months in order to establish a data record previously not available. TDEC and TVA will re-evaluate the monitoring frequency at the end of this 12-month period upon permittee's request. Considering existing toxicity data, the division agrees that Whole Effluent Toxicity testing can be changed from annually to once during the period. This will match the language in Part Ill, E. Biomonitoring Requirements and in the Rationale Part I, Section 1. Biomonitoring Requirements.

Comment 3: Page 15 of 25, B. Dike Inspections: Section.2.(b) of the permit should be revised to be more specific as to the circumstances in which the division should expect written notifications. The following language was suggested to be consistent with the agreed to language in the Johnsonville NPDES Permit (TN0005444): "Within 5 days of discovering a change in the impoundment that could reasonably be expected to indicate a compromise of the structural integrity of the dike (e.g., significant changes in seeps, boils, bulges, or cracks), the permittee must notify the division in writing describing the findings of the inspection, corrective measures taken, and expected outcomes. Failure to do so will be a violation of this permit." RESPONSE: Suggested language was included in the final permit.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 4 of NOD - 41 Comment 4: Page 17 of 25, E. Biomonitoring Requirements, Chronic: the following language (shown as bold and underlined)

should be used for clarification of toxicity sampling requirements: Permittee shall conduct a 3-Brood Ceriodaphnia dubia Survival and Reproduction Test and a 7-Day Fathead Minnow (Pimephales promelas) Larval Survival and Growth Test on the same samples of the final effluent from Outfall 001 once during the permit period and Outfall 002 annually (only when biocides are used). RESPONSE: Suggested language was included in the final permit.

Comment 5: The following serial dilutions used in toxicity testing were suggested (Outfalls 001 and 002):

Serial Dilutions for Whole Effluent Toxicity (WET) Testing at Outfall 001 4 X IWC 2 X

IWC instream

Wastewater Concentration (IWC) 0.5 X

IWC 0.25 X

IWC Control

% effluent 58.9 29.4 14.7 7.4 3.7 0
Serial Dilutions for Whole Effluent Toxicity (WET) Testing at Outfall 002 Permit Limit (PL) 0.50 X PL 0.25 X PL 0.125 X PL Control 0.0625 X PL
% effluent 100 50 25 12.5 6.25 0 In addition, following changes on Page 18 of 25, E. Biomonitoring Requirements, Chronic were requested (changes are shown as bold and underlined): Furthermore, if the results do not meet the acceptability criteria as defined in Short-Term Methods for Estimating the Chronic toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013 (or the most current edition), or if the required concentration-response review fails to yield a valid relationship per guidance contained in Method Guidance and Recommendations for Whole effluent toxicity (WET) Testing, EPA-821-B-00-004 (or the most current edition), that test shall be repeated. In addition, the third paragraph on this page should be deleted and replaced with the following paragraph for clarification: For Outfall 001, the toxicity tests specified herein shall be conducted once during the final 18 months of the new permit term and the results of these tests submitted with the next permit application. The toxicity tests at Outfall 002 specified herein shall commence no later than 90 days from biocide application. If no biocides are

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 5 of NOD - 41 added, Outfall 002 discharges consist of raw river water to which no chemicals are added. Future requirements may be added as a Biocide / Chemical Treatment Plan (B/CTP) is developed. RESPONSE: Suggested changes and language were included in the final permit.

Comment 6: Page 20 of 25, J. Ash Pond Volume Requirements: Free Water Volume (FWV) requirement of 40.5 MG should remain unchanged from the previous permit. Based on TVA's Free Water Volume reports submitted on November 30, 2009, the FWV was 86.2 MG RESPONSE: FWV in the proposed permit was listed as 40.5 MGD. Therefore, no permit revision is required as a result of this comment.

Comment 7: Additional corrections to the Rationale for biomonitoring language were suggested. RESPONSE: Since the January 2010 Rationale is not a legally binding document, changes are not made. in the terms of the permit regarding biomonitoring, the monitoring provisions have been updated as stated above in Response to Comment 5.

Comment 8: Page R-12 of R-43, 2. Ammonia Nitrogen — The table on this page should be modified to East Tennessee temperatures instead of West Tennessee temperatures in the calculations. RESPONSE: The commenter may be correct that different temperature value could be used in calculations. However, since monitoring requirement in the proposed and final permit are on report basis only, no changes or corrections are necessary.

Comment 9: Comments were received on the issue of Thallium limits, laboratory analyses, and Detection Limits. Factors to be considered in finalizing the permit requirements and limits should include the following factors: • Background concentration of Thallium in the Clinch River is <1 ug/l, per EPA Method 279.1. • TN WQC for Drinking Water Supply is 2.0 ugh and for Fish & Aquatic Life/Water & Organisms is 0.24 ug/I. • None of the accepted analytical methods have a detection level that is equal or lower then the Water & Organisms level of 0.24 ug/l. [Note: ICP-Mass Spectrophotometry analyses detection level is 0.3 ug/l] Consequently, procedures used for reasonable potential calculations result in a "negative number", indicating potential for toxicity requiring an effluent limit for thallium.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 6 of NOD - 41 RESPONSE: While the Water and Organisms Criteria Thallium limit listed in TDEC Chapter 1200-4-3 is 0.24 pg/L, we acknowledge the current EPA approved analytical methods do not measure down to that concentration. Since TVA data has been reported as "Less-Than" values, there is no basis for determining compliance against the WQC. Because of the availability of a more sensitive method, i.e., not using the ICP-MS Method 200.8. Accordingly, the renewed permit will require reporting of Thallium using this method to obtain 12 monthly data points. At the end of 12 months reporting, TVA and TDEC will reevaluate the need for further monitoring or a permit limit.

Comment 10: Additional details should be included in the study plan for documentation of thermal effects under Section 316(a) of Clean Water Act. TDEC should seek to reduce or eliminate detrimental impact of thermal effects by establishing grounds for a thermal variance, or discarding the thermal variance in favor of thermal pollution limits and monitoring requirements that are protective of the Clinch River. RESPONSE: The permit will extend the thermal variance, with the condition that TVA will revise the reservoir monitoring approach acceptable to both TDEC and EPA Region 4 during this permit cycle. The objective of the study plan will be to generate information sufficient to support a determination of whether the BRF alternative thermal limit under Section 316 (a) can be continued in the next NPDES permit. For this permit cycle, the RFAI data compiled by TVA upstream and downstream of BRF demonstrate that a balanced indigenous population is being maintained in the receiving water body.

Comment 11: TDEC Must Establish Technology-Based Effluent Limits in the Bull Run Fossil Plant NPDES Permit. While EPA's forthcoming ELGs will address the full suite of pollutants discharged by coal-fired power plants, the new rules will not be finalized for several years. In the interim, the Clean Water Act requires that TDEC use its best professional judgment to set BAT-based TBELs to limit pollution and protect the Clinch River. Specifically, EPA has identified 27 pollutants to analyze in CCW wastewaters, including: aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, selenium, silver, sodium, thallium, tin, titanium, vanadium, yttrium, and zinc. Using the wealth of data available from EPA and power plants in Tennessee, TDEC can and must use its best professional judgment to set BAT-based numeric effluent limits for heavy metals, such as the 27 pollutants listed above, present in CCW wastewaters.
RESPONSE: The BPJ Analysis is included in this NOD — following these Comments/Responses.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 7 of NOD - 41 The BPJ analysis addresses the process of setting numeric effluent limits for metals in the renewed permit, as well as EPA's ongoing process for publishing revised Effluent Limitations Guidelines (ELGs) and TVA's process of converting to dry ash handling. The regulation of BRF's waste streams was addressed by the 1982 Steam Electric Power Generating ELGs which are the basis for the technology-based effluent limitations in BRF's draft NPDES permit. The ELGs do not include metals, other than for chemical metal cleaning wastes. EPA regulations give permit writers broad discretion to determine whether and when to develop additional limits for waste streams or pollutants not covered by ELGs applicable to an industry category. The Clean Water Act does not require TDEC either to conduct a Best Available Technology (BAT) analysis or to impose BAT limits where TDEC has reasonably concluded, as in the case of BRF, that the pollutants will not be discharged at levels likely to cause toxic effects. In addition, EPA's 2009 study report on the Steam Electric Generating Point Source Category is a preliminary characterization of steam electric plant wastewaters and potentially available technologies. It is not determinative on the issue of BAT limits.

Comment 12: TDEC Must Establish Water Quality-Based Effluent Limits in the Bull Run Fossil Plant NPDES Permit. In addition to setting WQBELs in the Bull Run Fossil Plant NPDES permit, TDEC should consider adding the Tennessee River to the state's 303(d) listing of impaired waters for mercury, iron, cyanide, antimony, manganese, and aluminum, as levels of these pollutants already exceed the protective WQC set by Tennessee and/or EPA near the Bull Run Fossil Plant.
RESPONSE: An updated spreadsheet of reasonable potential calculations is attached to this NOD addressing all 27 pollutants listed in the comment 11. The reasonable potential calculations indicate instream concentrations of pollutants discharged from Outfall 001 do not exceed TN WQC. Therefore, no WQBEL are warranted. As EIP itself acknowledges, TDEC should set water quality based effluent limitations ("WQBELs") only "jiff the discharge of pollutants from BRF could cause or contribute to a violation of water quality standards in the Clinch River." EIP Comments, p. 3 (emphasis added). TDEC has determined that discharges of metals from BRF have no reasonable potential to cause or contribute to an in-stream excursion above Tennessee water quality criteria. As shown on the spreadsheet of BRF Intake data (shown later in the BPJ Analysis), background concentrations of metals do not exceed TN WQC. [Note: The thallium concentrations are reported as non-detect at the detection level of 1 ugh in 2007. Further information on thallium detection level is shown above in the Response to Comment 9.] We assume that a reference to the Tennessee River is a typographical error, and a reference should be for the Clinch River. This segment of the Clinch River is already listed in the current 303(d) list for mercury, PCBs and chlordane.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 8 of NOD - 41 Comment 13: TVA reports that the background concentration of mercury in the Clinch River as 0.2 pgIL—a level that exceeds Tennessee WQC for recreational waters (0.051 pg/L and 0.05 lig/L) by an order of magnitude. However, TDEC did not use this value in the Bull Run permit, and instead conducted water quality based effluent calculations using a mercury value of 0.1 Ng/L— half of the actual amount detected and reported by TVA. TDEC must correct and re-calculate mercury concentrations in the final permit for Bull Run Fossil Plant.
RESPONSE: The background concentration for mercury in the draft permit was based on analytical data available at the time. The mercury data were for analyses at detection levels which, while meeting TDEC's required detection levels, were greater than the applicable water quality criteria. More recently, samples of the BRF intake, ash pond discharge, and condenser cooling water discharge have been collected and analyzed by low level methods. The resulting values were 0.0025 lag/L, 0.012 pg/L and 0.003 pg/L respectively, all more than 4 - 10 times below TDEC's most stringent Water Quality Criterion (WQC) for this parameter (0.05 pg/L for recreational uses).

Comment 14: In TDEC's reasonable potential analysis, it must examine whether the discharge of CCW pollutants will cause, have the reasonable potential to cause, or contribute to an excursion above water quality standards. If TDEC finds such potential, it can rely on its narrative criteria for water quality, as required by Clean Water Act regulations, or use EPA WQC to provide sound scientific rationale to establish water quality-based effluent limits for discharges of CCW pollutants from Bull Run Fossil Plant to the Clinch River.
RESPONSE: See above response to Comment 12 for revised reasonable potential calculations.

Comment 15: Commenters urge TDEC to use its authority to put enforceable terms, deadlines and conditions in this draft permit to ensure that TVA does indeed close the wet CCW disposal areas at the Bull Run Fossil Plant. Specifically, TDEC should require remedial actions, or impose increased monitoring to ensure safe closure.
RESPONSE: TDEC authority under the Water Quality Control Act (TWQCA) addresses the characteristics of ash pond discharges and also addresses the placement of materials having the potential to impact state waters. This is the basis for the dike integrity inspection requirement in the permit as well as the closure plan requirement. However, the TWQCA does not necessarily authorize the division to mandate pond closure, rather that the pond be managed in such a way as to protect state waters. Since TVA has known for almost 9 months of TDEC's requirement for the closure plan and has stated plans for dry ash handling, TDEC will require in the renewed permit that TVA submit the closure plan in 90 days from the permit effective date.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 9 of NOD - 41 A requirement for quarterly updates on the dry ash conversion and ash pond closure processes is included in the final permit as follows: The permittee will provide quarterly updates on progress toward dry ash conversions and ash pond closure with the Discharge Monitoring Reports submitted for March, June, September, and December. The report must address, at a minimum, the estimated future date for complete closure and elimination of ash pond discharges as well as updated information on planning, design, and construction milestones for each quarter.

Comment 16: TDEC Should Correct and Revise Permit Condition D [Intake Screen Backwash]: The intake screen backwash discharged through Outfall 002 should not contain pollutants other than those previously present in the intake water. The discharge should not have a visible oil sheen. RESPONSE: Revision is made in the final permit.

Comment 17: TDEC Should Add a Permit Condition to Protect Water Quality The discharge activity shall not cause or contribute to violations of water quality criteria as stated in the TDEC Rules, Chapter 1200-4-3-.03. Under no circumstances may discharges exceed numeric water quality criteria for aquatic and human life as stated in Tennessee Water Quality Criteria, Tenn. Comp. R. & Regs 1200-4-3. RESPONSE: Part I.A.b. of the permit ("The wastewater discharge shall not contain pollutants in quantities that will be hazardous or otherwise detrimental to humans, livestock, wildlife, plant life, or fish and aquatic life in the receiving stream.") already addresses this point.

Comment 18: Commenters request that TDEC change the language in Permit Condition B(3) (Dike Inspections) to state: "the Director will re-open this permit to incorporate more stringent requirements or any applicable standards pertaining to the operation and maintenance of coal combustion waste impoundments." RESPONSE: The division will reopen the permit if terms and conditions of the current permit are not deemed protective of the applicable water quality standards. The proposed change does not enhance or limit director's ability to proceed with re-opening of the permit.

Comment 19: Permit Condition B should include the recommendations TDEC and findings in TDEC's Advisory Committee Report on the Kingston Disaster. Namely, the TDEC Advisory Committee recommended that:

TVA should provide site-specific quarterly reports of coal ash impoundment activity and analysis to TDEC; Ash Closure Plans and wet to dry transitions of coal ash ponds be conducted under the supervision of the TVA Dam Safety Group;

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 10 of NOD - 41 ❑ All reports and analyses for TVA wet storage facilities, dry storage facilities and landfills should be submitted to TDEC, including reports prepared by consultants and relevant to permits (such as stability or geotechnical reports, and inspection reports and recommendations); ❑ Calculations and Reports must be signed and sealed by a Registered Professional Engineer, registered in the State of Tennessee; ❑ Through the permitting process, TVA should prepare a detailed inspection regimen for each phase of operation, construction or closure, and inspections must be conducted by Registered Professional Engineers that have qualified training and experience; ❑ TDEC should develop criteria for impoundments and use criteria in permit Approval.
RESPONSE: TDEC already expanded the oversight of coal combustion waste facilities in Tennessee. Expanded oversight includes Divisions of Water Pollution Control, Solid Waste Management, Air Pollution and Water Supply. Most of the recommendations listed in this comment above were incorporated through our expanded oversight activities, and some as a part of this NPDES permit. Specifically, this final permit contains dike inspection reporting requirements, updated information on the progress of dry ash conversion and ash pond closure.

Comment 20: TDEC should require TVA to implement the National Incident Management System ("NIMS"), required by Homeland Security Presidential Directive (HSPD -5) and recommended by the TDEC Advisory Committee on the Kingston Disaster, to improve communications with other agencies in the event of an emergency. Any emergency plan for the Bull Run plant developed by TVA in conjunction with the NIMS should be included in this condition or otherwise as a permit requirement.
RESPONSE: The division, under the TN Water Quality Control Act, lacks direct authority to require TVA to implement NIMS, as this is a Presidential Directive affecting all government agencies. However, early this year, TVA management initiated a reorganization of the emergency response program and notified TDEC and the TN Emergency Management Agency of their plans to comply with NIMS. TVA is currently staffing the program, and developing procedures for submission to Congress and the public with a tentative completion date of August 2010. No new information is available to TDEC on the current status as of this writing. Based on past experience and knowledge of the risk levels of BRF ash pond dikes, the requirement for an Emergency Response Plan to address potential water quality emergencies is reasonable. For purposes of this NPDES permit, TVA Bull Run Fossil Plant must develop an Emergency Response Plan within 60 days of the permit effectiveness date which addresses the TDEC Advisory Board Lessons Learned: "a preparedness plan that consider[s] a boundary for potentially affected topographic features based on mud flow and wave propagation to develop requirements for CCW storage that will minimize any life threatening effects due to failure"

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 11 of NOD - 41 Under the TN Water Quality Control Act, TDEC can require TVA to submit information, such as this Plan necessary to protect public health and the environment: [See TCA 69-3-107. Duties and authority of the commissioner (10) Require the submission of such plans, specifications, technical reports, and other information as deemed necessary (emphasis added) to carry out the provisions of this part or to carry out the rules and regulations adopted pursuant to this part.]

Comment 21: TDEC Should Investigate Two Recent CCW Spills at Bull Run and Require TVA to Take Remedial Action. RESPONSE: The division is continuing to investigate referenced incidents. Upon completion of our investigation and consultation with other agencies, appropriate enforcement action(s) may be taken, if necessary.

Comment 22: TDEC Should Investigate Selenium Discharges at Bull Run Fossil Plant. In this permit cycle, TDEC should ensure that selenium levels are properly controlled in effluent from Bull Run Fossil Plant. Treatment technologies and methods of reducing selenium levels in CCW effluent should be utilized if necessary. RESPONSE: The enclosed reasonable potential analysis indicates the chronic and acute selenium concentrations protective of instream designated uses are 19 and 89 ug/L, respectively. Actual effluent concentration range as reported in the permit application is 7 to 15 ug/L. Therefore, although effluent limitation is not required, we've included a monitoring requirement in the final permit.

Comment 23: TDEC Must Prevent Backsliding in the Bull Run Permit and Require Manganese and Chromium Monitoring in the Final Permit at Outfall 001. TDEC removed pollutants and pollutant monitoring requirements, perhaps inadvertently, for manganese and chromium in the effluent limitations chart for Outfall 001. To avoid backsliding, TDEC should continue to require that Bull Run Fossil Plant control its discharge of manganese and chromium. At a minimum, TDEC should require monthly monitoring for both pollutants, but TDEC may find, after performing reasonable potential analysis for manganese and chromium, that effluent limits are also necessary. RESPONSE: Monitoring requirements for chromium are included in the final permit. Although TN has no WQC for manganese, the EPA recommended WQC is used in the RPA spreadsheet for manganese of 50 and 100 ug/l for chronic and acute toxicity, respectively. This calculation identifies that BRF discharge does not have reasonable potential to exceed the EPA recommended WQC.
Comment 24: Commenters request that TDEC establish numeric effluent limits for the pollutants listed in the NPDES permit for Outfall 001, including aluminum, arsenic, cadmium, copper, iron, lead, mercury, nickel, selenium, silver, thallium and cyanide. In addition, TDEC should require monitoring and effluent limits for the additional pollutants EPA identified in CCW wastewaters,

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 12 of NOD - 41 including antimony, barium, beryllium, boron, calcium, chromium, cobalt, magnesium, manganese, molybdenum, tin, titanium, vanadium, yttrium, and zinc at Outfall 001.
RESPONSE: As described in the Response to Comment 12, an updated spreadsheet of reasonable potential calculations is attached to this NOD addressing all 27 pollutants listed above. The RP calculations indicate mixed concentrations of Outfall 001 and the receiving stream do not exceed TN WQC. The renewed permit requires monitoring for metals on a monthly basis for those parameters for which TN has established a WQ criterion.

Comment 25: TDEC Must Place Effluent Limits and Monitoring Requirements for once-through cooling water (OTCW) in the NPDES Permit for Bull Run Fossil Plant at Outfall 002. Clean Water Act regulations set effluent limits for Free Available Chlorine and Total Residual Chlorine in OTCW. TDEC should require Bull Run Fossil Plant to use the best practicable control technology currently available ("BPT") to limit the discharge of free available chlorine ("FAC") from OTCW units. These BPT effluent limits apply to an individual generating unit at the discharge point of the individual generating unit, prior to combination with the OTCW from other units.
RESPONSE: As stated in the Draft Permit, TVA BRF no longer uses chlorine for biocide control of OTCW, but uses bromine or other oxidizers. Biocide addition does not occur routinely, in fact DMR reports for 2008-9 show that no biocides were employed. Monitoring is required in the final permit at Outfall 002 per the parameter Total Residual Oxidants to measure these oxidizing compounds in a technique similar to chlorine. Permit limitations for use of these oxidizers are equivalent to those for the use of chlorine.

Comment 26: Given the large flow rate of discharges from Bull Run Outfall 002 and the possibility that overall pollutant mass discharge could be significant, TDEC should set effluent limits and monitoring requirements in the draft NPDES permit for Bull Run Outfall 002.
RESPONSE: Outfall 002 should only discharge compounds found in the Clinch River, plus heated water and any biocides used for maintenance purposes. The permit limits, in addition to temperature, include total residual oxidants and effluent toxicity to address potential impacts on water quality. Other than heat, TDEC has no records to date of significant pollutant loadings from Outfall 002 that would warrant effluent limitations.

Comment 27: Although TVA was granted a CWA §316(a) thermal variance, the Clinch River is on the States 303(d) list for thermal pollution, and TDEC must investigate how to better control thermal pollution from Bull Run Fossil Plant in this permit renewal. For example, the cold water from the Norris Dam mixed with the hot water from Bull Run Fossil Plant may have a unique impact on aquatic life around the Bull Run Plant. The Bull Run Fossil Plant also pulls in, and discharges via once through cooling water, a significant portion of the river flow.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 13 of NOD - 41 TDEC should examine TVA's ability to reduce thermal pollution at Bull Run, and examine the overall impacts of cooling waters on aquatic life near Bull Run. Specifically, TDEC should require TVA to provide a plan for reducing thermal pollution, and to address the concerns raised in EPA's letter of June 30, 2009 before TDEC issues the final NPDES permit for Bull Run Fossil Plant.
RESPONSE: The division agrees with commenter's concerns regarding potential effects of thermal discharge on a balanced and indigenous population of fish and other aquatic organisms at this location. TVA's extensive studies to date will be further expanded under EPA's guidance during this permit cycle. EPA Region IV has indicated that additional aquatic data should be collected during the five-year duration of the subject permit to facilitate the Section 316(a) determination in the "next NPDES permit." (Permit 1111.) The renewed permit retains the alternative thermal limit as existing data demonstrate the maintenance of a balanced indigenous population ("BIP") in the receiving waterbody. TVA will be required to submit a study plan outlining proposed assessments to support continuance of the ATL. The plan will be designed to supplement existing information previously provided by TVA. EPA has agreed to this approach and will participate in the review of the plan and the resulting data.

Comment 28: TDEC should require TVA to monitor for TSS and oil and grease in addition to flow, pH, total copper and total iron. TVA must demonstrate compliance with Metal Cleaning Waste ELGs at Internal Outfall 005. RESPONSE: In EPA rules at 40 CFR 423.12, ELGs for BPT of Metal Cleaning Wastes require limitations of TSS, O&G, Copper and Iron. ELGs for BAT at 423.13 require limitations for copper and iron. In the renewed permit, these limits are set for TSS, O&G, Copper and Iron with compliance measured at Internal Monitoring Point 005 (referenced as Outfall 005 in the above comment). The corresponding changes are incorporated in the final permit (see table below).

I
OUTFALL 005 Metal Cleaning wastes

EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. ANENT. MAX. CONC. MAX. A_VLNT. MSRNINT. FRO NCI'. SAMPLE

TYPE (.13/0 iihk

1 .30 OW) (1b/dAy) FLOW Report (MGD) • Report (MGD)* 1/Batch EstImate Total Suspended Solids 30.0 - 100.0 - Grab Oil and Grease 15.0 -- 20.0 -- Grab COPPER,TOTAL 1,0 - 1.0 - "' Grab IRON, TOTAL 1.0 - 1.0 - Grab

' now shall be reported in Million Gallons per Day (MGD).

— Flow shall be estimated from pump logs

-- Samples shall be taken at the beginning and end of a discharge event for each batch treated.



### Comment 29 The permit should require semi-annual in-stream monitoring for metals at locations near the ash pond up to the time of the closure.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 14 of NOD - 41
RESPONSE: In-stream monitorincLhas been conducted twice yearly immediately downstream of the BRF site at the West Knox Utility District water intake since 1995 as required by previous permits. Metals concentrations in the mixing zone continue to comply with TN WQC for the Drinking Water Supply use classification at Rule 1200-4-3. For CY2006 thru June 2010, these data are discussed below:

• For Arsenic was reported three times with a value above the detection limit. Arsenic was reported as 0.0015 mg/L in the May 2007 sample (detection limit is 0.0010 mg/L) and again in November 2007 and May 2008. All other Arsenic analyses were reported Below Detection Limit. • Both Chromium and Lead values were all below detection limit except for May 2007 sample. Chromium was reported as 0.0015 mg/L (detection limit is 0.0010 mg/L) and Lead was reported as 0.0011 mg/L (detection limit is 0.0010 mg/L). • Selenium was reported two times with a value above the detection limit. Selenium was reported as 0.0017 mg/L in the May 2007 sample (detection limit is 0.0010 mg/L) and again in November 2007. All other Selenium analyses were reported Below Detection Limit. • Cadmium and Mercury analyses were reported Below Detection Limit (mercury levels reported using low-level tests are discussed in Response to Comment 13 above). The final permit will retain the requirement for semi-annual instream monitoring at the West Knox UD intake.

Comment 30: The RP analysis should include all the metals on page V-3 of the permit application. RESPONSE: All the metals are assessed in the updated RP Analyses shown on page NOD —15.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 15 of NOD - 41 Comment 31:

Concerns for ash pond operation and future closure should address potential for groundwater contamination. RESPONSE: Groundwater monitoring at the ash disposal sites is required by the TDEC Div. of Solid Waste Management (DSWM). DSWM records indicate that ongoing groundwater monitoring at BRF has detected metals at levels below MCLs for, among others, arsenic, cadmium, and silver. Assessment Monitoring was downgraded from Phase III to Phase II which consists of sampling groundwater semi-annually. 1 TVA has not developed quantitative estimates of BRF ash pond groundwater seepage rates or contaminant loadings to Melton Hill Lake. No estimates of groundwater loadings are available for comparison to the ash pond discharge. In other ash pond locations, this groundwater seepage rate has been found to be a potentially insignificant factor in affecting surface water as compared to the ash pond discharge to the Lake of 20 MGD. Since it's not feasible to measure the potential groundwater effect in the depths of the Lake, assessment of the aquatic community remains the only viable option. TVA has compiled data on Reservoir Fish Assemblage Index (RFAI) in Melton Hill Lake, upstream and downstream of BRF, every other year since 2001 2 . These data demonstrate a balanced, indigenous population has been maintained in the vicinity of the plant.

1 

### TDEC DSWM letter, Fugate/Cook to C.M. Anderson, TVA, Subj: Assessment Monitoring Phase II Required, October 21, 2009
2 

### TVA, Bull Run Fossil Plant, NPDES Permit No. TN0005410, 316(b) Monitoring Program, Fish Impingement at BRF During 2005 -2007, December, 2007.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 16 of NOD - 41

WATER QUALITY BASED EFFLUENT CALCULATIONS OUTFALL 001
Hardness as CaCO3 Stream

Allocation [ Stream Stream (1Q10) (30Q5) Waste Flow Susp.

Solids Hardness data: 145 mg,1 Clinch FM 66 TDC-C A ebiere Sta Ik160] RAW] 8420] 145 50 157.7 169.3 18.89 9
67 1 8 Fish & Aquatic Life I

WQ Cntena (1010) 2 1 3 1 4 t 5 roam Bckgmd. Conc."' Fish/Aqua. Lite

WO Criteria Effluent

Fraction Dissolved Outfall

In-Stream Allowable Calc. Effluent Comb 001 Cono'n Chronic Acute Chronic Chronic EFFLUENT CHARACTERISTIC Acute ACUte [ug 7 1] [ugh] [Fraction]

. rug/l] 530 Aluminum 1867 1.33 Antimony 6.5 Arsenic 2 150 340 150 340 693 1581 129 26 Barium 177 1 Beryllium 2.7 200 Boron 1297 0.2 Cadmium * 0.318 2.88 0.194 1.64 14.85 7 69 0.32 Calcium Chromium Ill 772.4 36.9 0.084 9177 439 42893 2046 21.67 5 NA Chromium IV * 11 16 11.00 16.00 31 54 Cobalt 4 4.0 Copper* 16 12.30 19.07 0.220 56.0 86.8 195 339 6.0 423 Iron 347 Lead * 2 3.76 98.55 0.152 24.72 634 107 2957 3 4067 Magnesium 4733 46.3 274 12.0 Manganese 50 SOO 1.0 50.00 100 40 0.005 Mercury, (T)** 0.770 1.4 0.77 1.40 4 7 0.17 15 Molybdenum 56 Nickel * 1 14270 71.2 641.2 0.210 339 3054 1581 3 1.3 14 Selenium Silver ' 5 20 1.0 20 18 88 5 3.5 6.095 1.0 14 6.09 3.53 Sodium 1.7 Thallium 2.0 40 Tin 40.0 23.3 Titanium 28.3 Vanadium Yttrium 30 Znt • 160.54 160.54 0.13 1246.54 1246.54 5701 5701 26.7 NA Cyanide (T)** Chlorine (T. Rea) 2.6 5.2 22.0 1.0 5.2 22.0 13 92 0.0 11.0 19.0 1.0 11.0 19.0 103 178 NA

10 11 I 12 13 14
In Stream Criteria Cato. Effluent Concentration 001 Human Health Water QualityY Cate a (300511 Outfall atertarganis OWS Organisms iter/Organis DWS amen EFFLUENT CHARACTERISTIC Organisms [ugh] [ug/I] lugid [ugl] Lug/11 ugti Aluminum 520 Antimony 5.6 5.6 6.0 22 22 24 5.3 10.0 10.0 34 Arsenic 10.0 41 41 41 Barium 2000 157 9846 Beryllium 4.0 15 4 Boron 307 Cadmium • 5.0 24 0.39 Calcium N/A Chromium Ill * 100.0 494 3 Chromium IV • Cobalt 4.33 Copper* 5.2 Iron 303 Lead • 5.0 16 2 Magnesium 10533 Manganese 50 100 41.6 291 53.3 Mercury, (T)** 0.051 0.050 2.0 0.2 0.2 10 0.17 Molybdenum 60 Nickel * 4600 610 100 22909 3034 494 8 Selenium 50.0 243 12 Silver 0.53 N/A Sodium Thallium -5.3 -6.4 0.47 0.24 2.0 2 1.8 Nn 49.7 Titanium 20.3 Vanadium NA Yttrium NA Zinc* 12.7 Cyanide {T)" 686 NA NA 140.0 140.0 200,0 686 Chlorine (T. Rea) NA NA = not applicable. * Denotes metals for which Fish & Aquatic Life Criteria are expres ed as a function of total hardness.The Fish & Aquatic Life criteria far this metal are in the dissolved form at laboratory conditions. The in-stream allowable criteria arid calculated effluent concentrations are in the total recoverable form. A background level of 0.002 ugiff. from February 2010 laboratory analyses- The chronic criterion for mercury is not converted to dissolved, as it addresses bioaccumulation rather than toxlcity. "' Stream background concentrations are taken from intake sample on the permit application- In cases where the background concentration was reported as less than a value. one half of value was used NOTE: Water Duality criteria for stream use classifications other than Fish & Aquatic Life are based on the 3005 flow.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 17 of NOD - 41

BEST PROFESSIONAL JUDGMENT ANALYSIS

Prepared by Robert Alexander
CONTENTS OF THIS ANALYSIS:
A. 1982 Steam Electric Power Effluent Limitations Guidelines B. 2009 EPA Steam Electric Power GeneratinPoint Source Category: Final Detailed Study Report (EPA 821-R-09-008) C. 2010 USEPA Rulemaking Process for ELGs for Coal-Fired Plants D. USEPA MEMORANDUM — NPDES Permitting at Steam Electric Fossil Plants, dated 7 June 2010 E. TVA Proposed Conversion of Wet Ash Handling to Dry Storage F. TDEC Procedures for Establishing Effluent Limits G. Comments on other fossil plant Draft NPDES Permits H. Conclusion - Permit Writer's Best Professional Judgment

A. 1982 STEAM ELECTRIC POWER EFFLUENT LIMITATIONS GUIDELINES (ELGS) EPA first issued effluent guidelines for the Steam Electric Power Generating Point Source Category (i.e., the Steam Electric effluent guidelines) in 1974 with subsequent revisions in 1977 and 1982. Steam Electric effluent guidelines are codified at 40 CFR Part 423 3 and include limitations for the following waste streams (emphasis added):

o Once-through cooling water; o Cooling tower blowdown; o Fly ash transport water; o Bottom ash transport water; o Metal cleaning wastes; o Coal pile runoff; and o Low-volume waste sources, including but not limited to wastewaters from: ■ wet scrubber air pollution control systems [Flue Gas Desulfurization, or FGD systems], ■ ion exchange water treatment systems, ■ water treatment evaporator blowdown, ■ laboratory and sampling streams, ■ boiler blowdown, ■ floor drains, ■ cooling tower basin cleaning wastes, and ■ recirculating house service water systems (sanitary and air conditioning wastes are not included) [40 CFR 423.11(b)].

3 47 Fed. Reg. 52290. November 19, 1982.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 18 of NOD - 41 1982 EPA 

### ELG Background Information: In the 1982 development document for ELGs, EPA addressed 4 : o waste streams listed in the part 1 above, and the four factors known to affect effluent characteristics: ■ type of coal burned ■ combustion process used ■ plant site characteristics, and ■ intake water quality.
o Priority pollutants, mainly inorganics (metals)
o Treatment and control technologies used in the 1970's and early 1980's. Regarding effluents from coal ash ponds, the significant points from the 1982 ELGs are:
o Numeric limitations were established for Total Suspended Solids (TSS), Oil and Grease (O&G), and pH. o For fly 

### ash transport water, no numeric limits for metals were established. ■ "EPA determined at proposal that the available data regarding the degree of toxic pollutant reduction to be achieved beyond the BPT were too limited to support national limitations." 5 ■ "The Agency considered requiring a zero discharge option for existing sources but rejected it because the high cost of retrofitting does not justify the additional pollutant reductions beyond BPT." 8
• The 1974 requirement for zero discharge of fly ash transport water was remanded in 1976. ■ "Many existing plants are achieving zero discharge [for fly ash sluice water] and new plants are at least as capable of implementing dry fly ash systems."'
o For bottom ash transport water, no numerical limits for metals were established. ■ "EPA did not propose BAT limitations for the priority pollutants. ■ Analysis of available wastewater sampling data did not indicate that a quantifiable reduction of toxic pollutants would be achieved beyond the BPT level of control." 8
• 1974 BAT contains the same TSS, O&G, pH and PCB limits as BPT, plus a recycle requirement of 12.5 cycles of bottom ash recycle water.
o For low volume wastes [i.e. FGD wastewater]., no numerical limits for metals were established.
• In 1982, EPA examined whether to prescribe numerical limits for metals such as arsenic, mercury, selenium, etc., but declined to do so because these substances were determined to be "present in amounts too small to be effectively reduced by technologies known to the administrator." 47 Fed. Reg. 52,290, 52,303-04 (Nov. 19, 1982).

4 USEPA, Development Document for Effluent Limitations Guidelines and Pretreatment Standards for the Steam Electric Point Source Category, EPA-440/1-82/029, November 1982.
5 Id. at page 496.
6 Id. at page 495.
7 Id. at page 497.
8 Id. at page 498.Table II-1
TECHUOLOC/ES EVALUATED AS CAPABLE OF ACUIEVIUG LIMITATIONS

BAT: Standards of

Performance: Pretreatment Standards: Pretreatment Standards: Wastestreams Existing Sources New Sources Existing Sources New Sources Once-Through Chlorine Minimize-Chlorine MiniCooling Water tion-Dechlorina-mizationLion Dechlorination Cooling Tower Use of alternative Use of alter- Use of alternative Use of BlowdoWo chemicals native chew..- .Gals/chemical precipitation chemicals alternative chemicals

Bottom Ash Sedimentation Transport( Water Fly Ash Dry transport Dry transTransport Water and disposal port and disposal
Chemical Chemical Chemical Precipi- Chemical Metal Clekz ing Wastes Precipitation Precipitation tation Prscipitation
non-chemical Reserved for Reserved for Reserved for Reserved for Cleaning future con- future con- future con- future conWastes sideration sideration sideration sideration
Low Vo vino Waste Sedimentation Sedimentation Sedimentation {includes boiler Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 19 of NOD - 41

o Best Available Technologies (BAT) evaluated as capable of achieving limitations are notlisted for Bottom Ash or Fly Ash sluice water or Low-Volume Wastes, as shown in Table II1 below 9 :

o Treated Fly Ash Pond effluent concentrations of only five metals were compared with discharges from various industrial processes as shown below:

Treatment Process Effluent Parameter (mg/I) Arsenic Copper Nickel Selenium Zinc Physical-Chemical byvarious industrial segments 0.02 to 0.1 0.1 to 7.8 0.09 to 1.9 0.02 to 0.08 0.1 to 6 ASH POND EFFLUENT Lime Softening 1 10 to 23 0.5 to 6 3 to 52 <2 to31 Li me-FeSO4 <1 to 3 7 to 23 2 to 10 3 to 32 <2 to 25

9 1d. at page 7, Section II - Conclusions

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 20 of NOD - 41



### o For bottom ash discharges, no data is shown for effluent metals concentrations.
o Wet fly ash handling/disposal had higher estimated costs than dry fly ash handling for new plants in 1979 dollars.
SUMMARY OF 1982 ELGs ■ ELGs cover pH, PCBs, Total Suspended Solids, and Oil and Grease. ■ EPA considered setting numerical limits for metals, but found inadequate data from which to set such numerical limits for toxic metals and low volume wastes (including FGD wastewater).

B. 2009 EPA STUDY REPORT In October 2009, EPA published a summary report with two purposes: ■ To review discharges from steam electric facilities, and ■ To determine whether ELGs should be revised. The report focused primarily on ash ponds and wastewater from FGD air pollution controls. The report: o Includes data on wastewater characteristics from coal fired power plants; o Identifies the wastewater treatment technologies reviewed:

FGD wastewater treatment technologies • Settling ponds • Chemical precipitation (hydroxide and/or sulfide) • Biological treatment ■ Constructed wetlands ■ Vapor-compression evaporation • Zero discharge Fly and bottom ash sluice water treatment ■ Settling ponds • Re-use of wastewater o Presents an overview of the industry profile and predicted future trends in the use of air pollution controls; and o Describes environmental impacts that have been linked to coal combustion wastewater. EPA developed the study using 30 pre-selected plants with 9 owners and obtained data from existing sources and a questionaire, and site visits with EPA sampling. TVA plants at Widows Creek FGD system and Paradise, KY were included in the study. Summary of Significant Points:

o FGD wastewater effluent concentrations identify toxic metals from three treatment technologies at the following facilities: ■ Settling pond at TVA Widows Creek, AL ■ Chemical precipitation at Tampa, FL; Homer City, PA; Mitchell, WV; and Belews Creek, NC. ■ Anoxic/Anaerobic biological treatment at Belews Ck, NC.

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 21 of NOD - 41



### o Ash pond effluent concentrations identify toxic metals at:
• Bottom ash pond — Homer City, PA; 1. Combined bottom and fly ash pond — Widows Creek, AL 2. Fly ash ponds — Mitchell, WV and Cardinal, OH

o Effluent metals data is presented as total metals and dissolved metals per EPA Method 200.8, low-level metals by various methods, and conventional parameters (COD, NH 3 , Chlorides, HEM, TDS/TSS). 1°

o Case Studies are shown:

1. Reuse of FGD wastewater in WV, OH, and NC 2. Reuse of fly ash and bottom ash wastewater in KY and PA

o EPA has determined the Study Report does not contain adequate data on treatment technologies and effluent concentrations to enable setting numerical effluent limits for toxic metals."

C. 2010 USEPA RULEMAKING PROCESS FOR ELGS FOR COAL-FIRED PLANTS EPA is currently drafting revised ELGs for coal-fired plants and issued a proposed Information Collection Request (ICR) questionaire on March 9, 2010. 12 o ICR was distributed in mid-2010 to selected fossil plants. o Responses from fossil plants are due 90 days after receipt absent an extension. o EPA analyses of the data will follow, with draft ELGs planned for 2012. o Final ELGs are planned to be issued in 2014. For detailed information and to see the questionaire, see Fact Sheet: Request for Comment on Questionnaire for the Steam Electric Power Generating Effluent Guidelines (February 2010). A relevant excerpt is quoted below: "Approximately 734 fossil- or nuclear-fueled steam electric plants will be required to complete Parts A and I of the questionnaire. This total includes approximately 495 coalfired, 9 petroleum coke-fired, 20 oil-fired, 168 gas-fired, 20 nuclear power plants, and 22 combination power plants. [...] One or more of these subpopulations will also be required to fill out certain additional detailed sections (for some sections of the questionnaire, the coal-fired respondents will be reduced to a subset of approximately 94 plants). EPA has determined that the data obtained through the Steam Electric ICR is necessary for EPA to review and revise the ELGs for the steam electric industry. The ICR will obtain information about steam electric power generating industry operations for use in characterizing waste streams and the processes that generate the wastes, environmental data, and the availability and affordability of technologies that may be used to reduce wastewater

io For example, See Table FGD-1 and AP-1 at end of document. For comparison, TVA effluent data is included in AP-1 later in this document.

11 EPA Supporting Statement, Questionnaire, February 2010, pg 2-1 at , httn://www.epa.2oy/waterscience/uide/stearn/supporta.pdf (TDEC has a paper copy of this document in the file, but the UAL availability is solely under EPA's control) 12 75 FR 10791, March 9, 2010

### Notice of Determination 

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### pollutant discharges associated with this industry. These data will be used to perform detailed technical and economic analyses that will support EPA's potential 

### development of numerical limitations or best management practices for wastewaters generated by steam electric plants [emphasis added] Key points of EPA Information Collection Request (ICR):

o At this writing, it is unclear whether or how much data will be available from TVA fossil plants depending on TVA plants being selected in the representative samples for detailed wastewater technology. All eleven of TVA's coal-fired electricity generating plants received the ICR questionaire.

o EPA will solicit data from ten coal plants having combined FGD/ash ponds for which EPA desires detailed data.

o EPA estimates that the total burden to the 393 coal-fired electric power plants for responding to the questionnaire will be approximately 200 hours per plant, for a total estimated effort of $4MM.

o Adequacy of Existing Data

• EPA has concluded the 2009 Study lacks specific information to set ELGs: "EPA compiled certain information through a recently-completed study [2009 Study Report] of the steam electric power generating industry and through public sources of information, but was not able to obtain the detailed plant-level and generator-level data that will be collected through this questionnaire." I4

• Although a similar data collection under the Clean Air Act is ongoing, "it will not collect information about the wastewaters generated from this equipment, nor will it collect information regarding related operating practices that affect the wastewater pollutant characteristics and generation rate."

o Cost Data

• Data on costs of achieving effluent reduction are not available from existing data sources [including the 2009 Study]: "EPA determined that the information available for regulated utilities are generally not sufficiently detailed and complete to support the plant level economic/financial impact analyses that will be conducted for the effluent guidelines rulemaking."

• Sources of cost data needed for ELG development include:
■ Federal Energy Regulatory Commission ■ USDOE Energy Information Administration ■ The Rural Utility Service (RUS) ■ Securities and Exchange Commission (SEC)

13 See EPA Supporting Statement, supra note 8 at 1-2.
14 EPA Supporting Statement, Questionnaire, February 2010, pg 2-1 at , http://www.epa.gov/waterseience/guide/steam/supporta.pdf

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• Edison Electric Institute (EEI)

• Depending on the data requested, EPA asks for plants to provide cost information for systems installed since 1985 or 1990. Relatively few plants have installed treatment systems since then, therefore EPA has selected these dates to obtain the data necessary to evaluate potential technology options.

o Parts A thru D and I will be submitted to all coal-fired plants, with Parts E, F, and G submitted to selected facilities of interest.

D. USEPA MEMORANDUM — NPDES PERMITTING OF WASTEWATER DISCHARGES from Flue Gas Desulfurization (FGD) and Coal Combustion Residuals (CCR) Impoundments at Steam Electric Fossil Plants, dated 7 June 2010. EPA Office of Wastewater Management issued this Memorandum to EPA Regions as interim guidance to assist permitting authorities in establishing permit requirements for steam electric plants, primarily for FGD discharges. At BRF, both the CCR stream (i.e., sluiced bottom ash) and the FGD discharges flow into a 30-acre settling pond. EPA's the guidance has been considered in this BPJ analysis.

E. TVA PROPOSED CONVERSION OF WET ASH HANDLING TO DRY STORAGE TVA plans to eliminate all wet ash and gypsum storage in the TVA system and convert its 11 operating coal-fired power plants to dry storage. As stated in the Draft NPDES permit , the TVA Board decided in July 2009 to convert wet ash to dry ash handling. 15

o Program Details (TN-only)

• Wet fly-ash will be converted to dry storage at Allen, Gallatin, Bull Run, and Kingston.
• Wet bottom-ash will be converted to dry storage at all eleven TVA fossil plants.
• Gypsum dewatering processes will be installed at Bull Run and Kingston.
• New ash disposal facilities will be developed to handle future plant operations.
• Eighteen existing ash and gypsum ponds will be closed and capped according to EPA guidelines for all of TVA area.
• High risk storage facilities will be converted first at Bull Run and Cumberland.
• TVA expects the conversion program to cost $1.5 to $2 billion and take 8-10 years to complete.
• Additional disposal facilities are planned for future plant operations.

o An 80% reduction of ash sluice water at KIF is proposed for dry fly ash handling, with the effluent flow from Outfall 001 dropping from 40.5 to 15.3 MGD. 16

15 http://www.tva.govinews/kingston/dry ash.pdf

16 TVA, Final Environmental Assessment, KINGSTON DRY FLY ASH CONVERSION, Roane County, Tennessee, March 2010, pg 26, 29 available at http://www.tva.2ovienvironment/reports/lcif dry ash/FEA..pdf.

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o Conversions Planned for Each TVA Fossil Plant:
• Allen (near Memphis, TN; 3 units; 990 MW)

• Wet fly ash to dry storage
• Wet bottom ash to dry storage
• Bull Run (near Oak Ridge, TN; 1 unit; 950 MW)

• Gypsum dewatering
• Wet bottom ash to dry storage
• Cumberland (northwest of Nashville, TN; 2 units; 2,600 MW)

• Wet bottom ash to dry storage
• Gallatin (northeast of Nashville; 4 units; 1,255 MW)

• Wet fly ash to dry storage
• Wet bottom ash to dry storage
• John Sevier (near Rogersville, TN; 4 units; 800 MW)

• Wet bottom ash to dry storage
• Kingston (near Kingston, TN; 9 units; 1,700 MW)

• Wet fly ash to dry storage [Scheduled for completion in 2011]
• Wet bottom ash to dry storage
• Gypsum dewatering The most recent information regarding conversion at BRF indicates:

• Wet bottom ash to dry storage completion in 2012
• Gypsum dewatering completion in 2013.
F. COMMENTS ON THE DRAFT PERMIT(S)
The Draft NPDES Permit for the TVA Bull Run Fossil Plant establishes effluent limits for parameters listed in the 1982 ELGs and previous permits: pH, Total Suspended Solids, and Oil and Grease. In addition, the draft permit required monitoring of toxic metals:

OUTFALL 001 EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY
EFFLUENT CHARACTERISTIC AVG. CONC. AVG.

AMT. MAX. CONC. MAX.

AMT. MSRMNT.

FRQNCY. SAMPLE

TYPE (uWL) (lb/day) (ug/L) (lb/day) Arsenic (T) N/A N/A report N/A Monthly Grab Cadmium (T) N/A N/A report N/A Monthly Grab Copper (T) N/A N/A report N/A Monthly Grab Lead (T) N/A N/A report N/A Monthly Grab Mercury (T) N/A N/A report N/A Monthly Grab Nickel (T) N/A N/A report N/A Monthly Grab Selenium (T) N/A N/A report N/A Monthl Grab Thallium (T) N/A N/A report N/A Monthly Grab

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### Zinc (T) N/A N/A report N/A Monthly Grab The renewed permit will add the following metals to the monitoring requirement — the permit will thus require monitoring for all metals which are listed in current TN Water Quality Criteria: Antimony, Barium, Beryllium, Chromium, and Silver Commenters on the draft permit have stated that TDEC must establish Technology-Based Effluent Limits for toxic metals: 17

"Where EPA has not yet promulgated ELGs for particular pollutants discharged by a given point source category, the CWA requires TDEC to stand in the shoes of EPA and use its best professional judgment ("BPJ") to set case-by-case TBELs for these pollutants in NPDES permits. In addition to the TBELs required at Outfall 001 and discussed above, commenters request that TDEC establish numeric effluent limits for the pollutants listed in the NPDES permit for Outfall 001, including aluminum, arsenic, cadmium, copper, iron, lead, mercury, nickel, selenium, silver, thallium, and cyanide. In addition, TDEC should require monitoring and effluent limits for the additional pollutants EPA identified in CCW wastewaters, including antimony, barium, beryllium, boron, calcium, chromium, cobalt, magnesium, manganese, molybdenum, tin, titanium, vanadium, yttrium, and zinc at Outfall 001 and 011. [...] Using the wealth of data available from EPA and power plants in Tennessee, TDEC can and must use its best professional judgment to set BAT-based numeric effluent limits for heavy metals, such as the 27 pollutants listed above, present in CCW wastewaters." This portion of the Notice of Determination specifically addresses this comment. Responses to other comments received during the public review process are addressed separately.

G. TDEC PROCEDURES TO DEVELOP ASH POND EFFLUENT LIMITS 1) OVERVIEW TDEC rules require use of Best Professional Judgment (BPJ) when federal ELGs are not applicable: For industrial discharges without applicable federal effluent guidelines, best professional judgment should be employed to determine appropriate effluent limitations and standards. I8
Federal ELGs are both existing and applicable to waste streams in question. Nevertheless, TDEC must follow the procedure defined under 40 CFR 125.3 to impose Technology-based treatment requirements for discharges on a case-by-case basis, using BPJ:

17 Environmental Integrity Project letter, dated March 16, 2010.

18 TDEC, Rules of TDEC, Div. of WPC, Chapter 1200-4-5, Permit Limitations and Standards, Sec 1200-4-5- .01(1)(b)(2)

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### Technology-based treatment requirements may be imposed through one of the following three methods: [...] On a case-by-case basis under section 402(a)(1) of the Act, to the extent that EPA promulgated effluent limitation are inapplicable. 19 Again, federal ELGs are both existing and applicable to waste streams in question. Under 40 CFR 125.3 and Section 402(a)(1) of the CWA, to the extent that ELGs are inapplicable, the permit writer must consider: (1) the appropriate technology for the category class of point sources of which the applicant is a member, based on all available information, and (2) any unique factors relating to the applicant. 2) POLLUTANTS ADDRESSED BY PUBLISHED EFFLUENT GUIDELINES Prior to establishing BPJ-based limits for a pollutant not regulated in an effluent guideline, the permit writer should ensure that the pollutant was not considered by EPA while developing the ELGs. That is, BPJ-based effluent limits are not required for pollutants that were considered by EPA for regulation under the effluent guidelines, but for which EPA determined that no ELG was necessary. In developing the 1982 ELGs, EPA considered but did not establish numeric ELG's for toxic metals due to lack of available data. In 2005, EPA after reviewing TRI and NPDES data, hasdecided to revisit ELGs from power plants. EPA is currently drafting revised ELGs for coalfired plants and issued a proposed Information Collection Request (ICR) questionnaire on March 9, 2010. Responses to the ICR will be analyzed by EPA, with draft ELGs planned for 2012. Final ELGs are planned to be proposed in 2014.

3) SECTION 304(B) FACTORS TO BE CONSIDERED IN SETTING BPJ LEvirrs20 Factor 1. Age of equipment and facilities involved Bull Run Fossil Plant (BRF) began operation in 1967 with one boiler, known as one of the largest and most efficient in the US. BRF capacity is reported at 870 megawatts burning up to 7300 tons of coal per day. The ash pond treats sluice water for both bottom ash and gyspum wastewater from the Flue Gas Desulfurization system (since 2009). The fly ash handling system at BRF was converted to a dry fly ash handling system. Prior to this, all fly ash and bottom ash was sluiced to the ash pond complex. Since the conversion, fly ash which is separated from the flue gases in electrostatic precipitators and collected in hoppers is pneumatically collected dry and blown to a fly ash silo. 21

19 

### 40 CFR 1325.3(c)(2)

20 

### 40 CFR 125.3(d)

21 

### Stantec, TVA Ph. I Facility Assessment, BRF, June 2009, pg. 2.

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### Dry fly ash that is not marketed can be conditioned with water and loaded into dump trucks for transport to the fly ash disposal or utilization areas. The maximum active area of exposed dry fly ash will be 10 acres or less (Robinson 2000). As stacking areas become inactive, they will be closed with an interim cover. The dry fly ash stack is graded to a 1% to 2% slope at the end of each day to limit ponding and encourage sheet flow runoff. Runoff from the dry fly ash stacking area drains to a sedimentation pond where it evaporates or overflows into the coal storage yard pond which is manually pumped to the ash pond as needed (Ross 2000). 22 Although BRF collects most of the fly ash dry, it retains the capability to sluice fly ash to the ash pond complex. Fly ash is sluiced during unit start-up and during operational problems that compromise the reliability of the dry fly ash collection system. In recent years, BRF has sluiced as much as 70,000 tons of fly ash annually to the ash pond. BRF recently utilized all of the fly ash produced at the plant for development of the Lost Ridge Industrial Park
Bottom ash collects in the bottom of the boiler and is periodically washed from the boiler bottoms with jets of water and sluiced to a bottom ash dewatering area within the ash pond complex. The bottom ash is removed from this area with pan scrapers and then carried to stacking areas within the ash pond complex. 23 The age of BRF combustion equipment is a factor that may be affecting coal ash wastewater. However, data does not exist as to specific effects. The age of the TVA ash pond impoundments is not a significant factor in examining effluent quality — newer or older impoundments can produce the same settling performance. The age of ash transport equipment and process is very relevant — ash sluicing practices and equipment are unchanged for almost 50 years. During this permit term, it is likely that TVA will replace BRF equipment and processes with conversion to dry bottom ash handling and gypsum dewatering. Although the 1982 ELGs established the dry fly ash technology under New Source Performance Standards (NSPS), this rule is not applicable to wet ash treatment process used at BRF. As noted in the EPA 2009 Study Report, development of future fly ash handling will be based on dry transport: More plants in the combined data set operate wet bottom ash handling systems than wet fly ash handling systems. Fewer wet fly ash systems are expected because the NSPS promulgated in 1982 prohibit the discharge of wastewater pollutants from fly ash transport water. Not surprisingly, EPA has found that the steam electric units

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### generating wet fly ash transport water tend to be older units, while dry ash handling systems tend to be operated on newer units. 24 Notwithstanding the fact that BRF is an older unit (pre-1982), the fly ash system has already been converted from wet to dry, and TVA plans to convert the handling of bottom ash and gypsum from wet to dry systems. Factor 2: Process employed BRF ash disposal involves sluicing bottom ash into a 30-acre ash pond flowing into a stilling pond and discharge of final effluent to Melton Hill Lake at Clinch River mile 48. FGD scrubber wastewater is mixed with sluiced bottom ash. Fly ash originates from operation of electrostatic precipitators and is transported to the dry ash stacking area: BRF is expected to burn between 2.0 and 2.2 million tons of coal annually through at least 2014. The coal averages 9.59% ash, therefore, total ash production will range from approximately 191,000 to 210,000 tons of ash per year. 25 The type of process used at BRF or any fossil plant is a unique combination of factors which create wastewater characteristics specific to each plant. Dominant factors affecting coal ash wastewater are:

• type and mixture of coal burned,
• coal handling practices such as washing and pulverizing,
• intake water quality,
• type of boiler, and
• waste stream source (bottom ash, fly ash, gypsum, etc.) Toxic metal constituents in coal ash are identified in the 1982 ELGs showing variations in coal ash composition based on anthracite, bituminous, subbutiminous, and lignite coal
sources. 26
For example, a description of fuel source at BRF is stated below: Prior to year 2000, Bull Run burned low sulfur coal from eastern Kentucky and Tennessee. To reduce sulfur emissions Bull Run switched to an even lower-sulfur coal from eastern Kentucky in January 2000. 27

24 EPA Steam Electric Power Generating Point Source Final Detailed Study Report, 2009, pg 5-2 25 WA, Draft Environmental Assessment - SELECTIVE NONCATALYTIC REDUCTION PROJECT- BULL RUN FOSSIL PLANT Anderson County, TN May 2002

26 See USEPA, Development Documents, supra note 2 at 144. 27 TVA, Draft Environmental Assessment - SELECTIVE NONCATALYTIC REDUCTION PROJECT- BULL RUN FOSSIL PLANT Anderson County, TN, May 2002

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 29 of NOD - 41 Factor 3: Engineering aspects of application of various control techniques Settling is the predominant control technologies for fly ash sluice water. Table 5-6 shows that 95 percent of the plants in the combined data set that handle any amount of fly ash wet send the fly ash transport water to settling ponds. Sixty-five percent of the fly ash ponds from the combined data set receive both fly ash and bottom ash. Only one of the fly ash ponds included in the combined data set is completely segregated (i.e., it receives only fly ash wastewater). 28 The control technology for bottom ash sluice water involves dewatering bins, settling, or both. The plants within EPA's combined data set that operate wet bottom ash handling systems send their bottom ash transport water to dewatering bins, settling ponds, or both. EPA has observed that most bottom ash settling ponds also receive other plant wastewaters. In response to the data request, no plants reported operating segregated bottom ash ponds. Table 5-7 shows that 90 percent of the plants in the combined data set that handle the bottom ash with a wet system transfer the bottom ash transport water to a settling pond for treatment. Only 18 percent of the plants are operating dewatering bins prior to the settling pond. As shown in Table 5-7, there are more plants that keep their bottom ash transport and fly ash transport waters segregated than not. 29 At BRF, wastewater treatment is performed in a 30-acre settling pond and stilling pond for the combined flow from bottom ash processes, FGD wastewater, metal cleaning wastes, coal yard runoff, and other minor sources. By their nature, settling ponds are designed for gravity separation of ash solids with discharge of supernatant to surface waters. While ash ponds are not designed to treat dissolved metals from sluiced ash or other wastewater sources, they are very effective in removing metals that are present in the waste stream in particulate form.
USING EFFLUENT DATA TO EVALUATE CONTROL TECHNOLOGY Availability of effluent data on wastewater treatment performance for ash ponds is described in Section 2 above, describing EPA's national effort to revise ELGs. Pending completion in 2011-12 of EPA's data collection, two sources 30 are currently available to TDEC regarding effluent concentrations of toxic metals from ash ponds — (1) EPA's 2009 Study Report, and (2) Actual effluent data from TVA's operations.

28 USEPA, 2009 Final Study Report, supra note 24 at 5-11
29 Id., pg 5-12. 30 As noted in the CommentlResponse portion of this NOD, data for concentrations of effluent metals will be available following issuance of the BRF permit — monthly analyses will begin in 2010.

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### EPA 2009 Study Report The most representative data from the 2009 EPA Study Report are effluent metals concentrations from the combined ash settling pond at TVA Widows Creek - summarized in Table 5-9 for: aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, selenium, sodium, thallium, titanium, vanadium, yttrium, and zinc. Table 5-9 is copied later in this document - note that this table does not include silver and tin.
TVA Ash Pond Effluent Data TVA has provided effluent concentrations from BRF as shown on the following page. Data is presented from permit renewal applications submitted in 1998, 2003, and 2007 - each entry is based on analysis of one (1) sample. Comparison of these data indicates a wide range of effluent concentrations. Concentrations of arsenic, for example, are described below:
• BRF permit application data ranges from 11 — 53 ug/l.
• EPA data ranges from Non-Detect at 10 ug/1 to 150 ugh per Table 5-9.Units are in lig/L I3RF 001 BRF Intake

Form 2C Form 2C Form 2C Form 2C Form 2C Form 2C
Parameter SYM 1998 SYM 2003 SYM 2007 MEAN SYM 1998 sym 2003 SYM 2007 MEAN 1 Aluminum 770 390 400 520 190 < 50 350 197 2 Antimony 5 < 1 9.9 5.3 < 1 6.1 < 1 2.70 3 Arsenic 38 53 11 34 < 1 < 1 < 1 1.0 4 Barium 100 110 290 166.7 20 40 36 32.0 5 Beryllium < 1 < 1 < 10 4.0 < 1 < 1 < 1 1.0 6 Boron < 500 < 200 220 306.7 < 500 < 200 < 200 300 7 Cadmium 0.4 < 0.1 0.68 0.4 < 0.1 < 0.1 < 0.5 0.23 8 Calcium N/A N/A N/A N/A N/A N/A N/A N/ A 9 Chromium 3 4.1 1.5 2.9 < 1 < 1 < 1 1.0 10 Cobalt 2 < 1 < 10 4.3 < 1 < 1 < 10 4.00 11 Copper 7 3.6 5 5.2 < 1 ' 3 3 2.33 12 Iron 520 260 130 303.3 260 230 2200 897 13 Lead 2 < 1 2 1.7 2 < 1 1.6 1.53 14 Magnesium 9600 10000 12000 10533.3 9400 10000 12000 10467 15 Manganese 54 37 60 50.3 42 60 93 65 16 Mercury 't < 0.2 < 0.1 < 0.2 0.2 < 0.2 < 0.1 < 0.2 0.17 17 Molybdenum 50 43 87 60 < 20 < 20 7.8 15.9 18 Nickel 8 7 8.5 7.8 < 1 < 1 13 5.0 19 Selenium 7 13 15 11.7 < 1 < 1 < 1 1.0 20 Silver t < 1 < 0.1 < 0.5 0.5 < 1 < 0.1 < 0.5 0.53 21 Sodium N/A N/A N/A N/A N/A N/A N/A N/A 22 Thallium T < 2 < 2 1.4 1.8 < 2 < 2 < 1 1.67 23 Tin < 50 < 50 49 49.7 < 50 < 50 52 50.7 24 Titanium 28 14 19 20.3 < 5 < 5 < 10 6.67 25 Vanadium N/A N/A N/A N/A N/A N/A N/A N/A 26 Yttrium N/A N/A N/A N/A N/A N/A N/A N/A 27 Zinc 8 < 10 20 12.7 < 6 < 10 22 12.7 O m cf)



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### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

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### Using Ash Pond Effluent Data from Similar Facilities Comparison of data shown in the EPA 2009 Study report between Widows Creek and BRF is difficult at best, and illustrates how fuel, facility, and operational characteristics result in wide variations in effluent metals concentrations. These characteristics are mentioned above, and include:

■ type of coal burned, ■ low-sulfur blend of coal, ■ combustion process used, ■ plant site characteristics, and ■ intake water quality. In fact, the following table illustrates a variability of coal combustion management practices at TVA's fossil plants:

Plant Fly Ash Bottom Ash FGD wastewater JSF Dry Sluice water No FGD BRF Dry Sluice water Piped to ash pond KIF Sluice water Sluice water Separate Gypsum Disposal Area JOF Sluice water Sluice water No FGD CUF Sluice water Sluice water Piped to ash pond GAF Sluice water Sluice water No FGD ALF 

### Sluice water Sluice water No FGD

Statistical Variability of Ash Pond Effluent Concentrations Ash pond effluent characteristics vary over time. Variations occur due to a number of factors, including changes in production cycles, variation in responses of ash ponds to influent changes, and, to a degree, seasonal changes in temperature and sunlight. NPDES permit procedures, including EPA rules at 40 CFR 122.44(d)(1), require TDEC to use a procedure that accounts for effluent variability. When developing a BPJ limit, permit writers can use an approach consistent with EPA's ELG statistical approach. Specifically, the daily maximum limitation can be calculated by multiplying the long-term average by a daily variability factor. The monthly maximum limitation can be calculated similarly except that the variability factor corresponds to the distribution of monthly averages instead of daily concentration measurements. The daily variability factor is a statistical entity defined as the ratio of the estimated 99 th percentile of a distribution of daily values divided by the mean of the distribution. Similarly, the monthly variability factor is typically defined as the estimated 95 th percentile of the

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 33 of NOD - 41 distribution of 4-day averages divided by the mean of the monthly averages. A modified delta-lognormal distribution can be fit to concentration data.Variability factors can then be computed for a facility distribution. The modified deltalognormal distribution models the data as a mixture of non-detect observations and measured values. This distribution is often selected because the data for most analytes consists of a mixture of measured values and non-detects. The modified delta-lognormal distribution assumes that all non-detects have a value equal to the detection limit and that the detected values follow a lognormal distribution. 31

Factor 4: Process Changes As discussed above, TVA is underway with planning and design to convert all wet ash and gypsum storage to dry storage. The conversion from wet sluicing of fly ash to dry stacking has already been achieved, and plans are underway to make wet to dry conversions for bottom ash and gypsum. Major reduction in wastewater flow through the ash pond is predicted from these projects. For example, the Kingston dry fly ash handling project will reduce ash pond effluent flow by approximately 80%, from 40 to 15 MGD. Based on public statements made by TVA regarding conversion to dry ash to eliminate ash sluice water, this process change negates the need for consideration of additional controls, since no additional technology could be installed sooner than the dry ash conversion systems.

Factor 5: Non-water quality environmental impact including energy requirements There is little or no information in current publications providing an insight for comparison of non-water environmental impacts of various technologies. Lack of information presents itself as an obstacle for the division in order to impose or even suggest BPJ-derived technology-based limitations on any facility in Tennessee. Given that this aspect of analysiscannot assist us in selecting an optimal treatment technologies for coal ash wastewater, nonenvironmental impacts cannot be identified (or used in a decision-making process) pending EPA's publication of revised ELGs, expected in 2013.

Factor 6: Cost of achieving effluent reduction A reasonable estimate of cost for various technology options, as presented in the 2009 EPA report, combined with publically available financial data, communications with permitted facilities and consulting firms can be made. There are several aspects of such analysis that

31 EPA, NPDES Permit Writers Manual, 1996,Sec 5.1.4

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### may limit the division's ability to require, at this time, one technology solution over another. A distinction must be made between existing and new sources. It is likely that retrofitting technology solutions on aging fossil plants may be a cost-prohibitive option. A much more detailed financial analysis, beyond the scope of BPJ-based limits, and expected as a part of ELG development, would be necessary in order to make such decision. Considering the imminent promulgation of new/modified ELGs for this industry, it is our opinion that mandating a technology change at this time could have long-lasting negative effects. The reasons are as following: there is no definitive guidance (or an indication) what will be the technology of choice in the final ELGs. Such discrepancy in decision-making may have an consequence of imposing a BPJ technology based limit ultimately not deemed to be a BAT. Associated cost with such inconsistent application of technology-based solutions could be enormous and a waste of public resources. Furthermore, one of the most important aspects of ELGs is to "level the playing field" on a national basis. Establishing potentially different BPJ technology-based limits at various states in the region (or even nation-wide) would be counterproductive, and would go against the intent of the rule.

Conclusion — Permit Writer's Best Professional Judgment 

### For the permit term of 2010 — 2013 (watershed cycle year), the NPDES permit for TVA Bull Run Fossil Plant should incorporate non-numeric Best Management Practices to control concentrations of toxic metals as described herein. Consistent with 40 CFR 122.44(k)(3), the BMP approach is appropriate because establishment of numeric limits is infeasible pending EPA publication of revised Effluent Limitations Guidelines. Furthermore, during this permit term, TVA will be converting the BRF process to dry ash handling with major reductions of pollutant loading and developing plans for pond closure. More detailed conclusions are presented below:
A. Establishment of numeric limits for toxic metals is infeasible for the following reasons:
1. Limited data - Effluent data for toxic metals consists of only three measurements by TVA over the previous 14 years; most effluent metals concentrations are less than detection. 2. Due to limited number of data points, accurate determination of permit limits based on effluent variability cannot be performed. 3. BRF effluent concentrations, when compared to other fossil discharges, are found to be highly variable due to multiple factors discussed in text above.

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### 4. The EPA 2009 Study report does not provide enough effluent characterization of available technologies to enable establishing numeric effluent metals limits.

B. Cost data is not available to determine economic achievability pending publication by EPA of revised ELGs.
C. Non-water quality environmental impacts, such as energy requirements or handling/disposal of dry ash conversion can not be identified, pending publication by EPA of revised ELGs.

D. NPDES permits for TVA fossil plant ash pond discharges shall include permit conditions requiring Best Management Practices (BMPs) since establishment of justifiable numeric effluent limitations is currently infeasible. 1. Effluent guidelines are not available to prescribe numeric effluent limits for toxic metal discharges from TVA ash ponds nor to guarantee water quality sufficient for the protection of indigenous aquatic life. Clean Water Act rules provide for pollution controls supplemental to effluent limitations guidelines, known as Best Management Practices, or BMPs. In addition to the conditions established under 122.43(a), each NPDES permit shall include conditions meeting the following requirements when applicable. (k) Best management practices (BMPs) to control or abate the discharge of pollutants when: (1) Authorized under section 304(e) of the CWA for the control of toxic pollutants and hazardous substances from ancillary industrial activities; (2) Authorized under section 402(p) of the CWA for the control of storm water discharges; (3) Numeric effluent limitations are infeasible; or (4) The practices are reasonably necessary to achieve effluent limitations and standards or to carry out the purposes and intent of the CWA. 32 (emphasis added) 2. BMPs may be incorporated as permit conditions to specifically address controls on toxic metals in ash pond discharges. ■ These controls can be site-specific to BRF operations and practices to address the circumstances of individual fossil plants. ■ Each practice must be developed and measured to document the relationship between operations and effluent metals concentrations.

32 40 CFR 122.44 (k)

### Notice of Determination NPDES Permit - TVA Bull Run Fossil Plant

Page NOD - 36 of NOD - 41 ■ BMPs 

### should be established based on guidance shown in Attachment 1 with submission of a BMP Plan for division review within 60 days following the permit Effective Date. 3. Uses of BMPs are a fundamental part of major NPDES permitting programs for CAFO, stormwater, and construction stormwater controls. 4. Development of BMPs will closely correspond to, and incorporate best practices from TVA ash pond closure projects following conversion to dry bottom handling and gypsum dewatering efforts. The BMP Plan submitted within 60 days following the effective date of this permit shall be amended as necessary to incorporate features of the dry bottom ash and dry gypsum handling projects implemented in the future. The amended plan must be submitted for division review at least 60 days prior to operation of the converted system.

### Table 54. Ash FoHd Effluen C. centrations

An to .

Unit Homer CitT - Effluent from Bolton .Ash Fond ' Widows Creek -

Effluent from Combined A.* Pond ' liatchell - Effluent

from. Ily - Ash Pond ' _ Cantina-Effluent

from. fly Ash Pond Lb

: :Routine 1,:fetah .- Total Abtrwrtfun. 

### 7 00.7 ligt 323 1:,0 +0 404 344 .43abarmy 200.7 P&L rD (20.0) 1 , 7D (20_0) 24.6 71.1 Ara 200.7 Pgi- ND (100) 36.2 150 77.6 3;_num. 200.7 ligi• 101 227 133 1d5 3aeryiliinx, 200.7 ligl- I , ID (5.00) ND (5 .00) ND (5.00) NJD (5 CO) .3 , roa 200.7 ligl- 396 2..210 2,350. 1„:.:>0

e. 200.7 1.1.1 , ..1. 'I,ID (5,00) ID (500) .1NTD (5.00) I , D (3 CO:: Cad= 200.7 LI g:L 113f,000 56,500 115,000 5S,400 Caxmium. 200. • lig1T- 111(10_0) 13.5 15„9 ND (100) Cabal: 200.7 lIPL. ND (50_0) I , D (50.0) ND (50.0) ND 0.0) C'o p pe: 200.7 lig" 1D(10..0) 1 , 0) (10..0) ND (10.0) ND (10_0 Loa 200.7 1.10- 35 5 114 ND (100) ND (100)

_ea. d. 200.7 lig. 1 ID (50_0) I , ,D (500) ND (50.0) 1,17 (500) Magesium 200.7 lig" 31,SZO .5.660 21000 17.900 3.-fanganese- 200.7 pg:L 12S I , I) (15_0) ND (15.0) 64.7 Iiaraci 245.1 Pg

. L ND (0.200) Is•TD (0.200) N.D (0_20D) ND (0.200)

.... 1 .1.c17...bdatuiz 200.7 Figl. 19:7 143 3S 361 'Mae] 200.7 lig:L. ID (50..0) ND (50.0}o ND (50.0) ND (50.0)

S 4: 4Fri ium 200.7 PO- 6_02 16.2 l77 44.5 Sodium 200.7 ligl 21.300 526,000 70,800 Tbaltittre. 200.7 1ig° 1 - ND (110) ND (10.0) ND (10.0) I , D (10.0) 1-Lrtiitial 2 - 1.1g.1- 1.-7D (10.0) 14.5 12.16 ND (10.0) Vaaathi.nr. 200. - lIg 1 - ND (20.0) 66.5 1 10 104 77:rtitilla. 

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### Table 5-9, A.511 Pond Effluent oncentrations



## .

Anilre Method 

## •

Unit Hamer 

## cityEffluent from Bottom Ash Pond -1- viadaws -creak -

Effluent from Combined Ash Pond ' Mitchel-Effluent

from. Ely Ash Pond fr 

## _ C2rdin21- Effluent

from Ely Ash Pend "" fr. Low-Level Metals - Total _korimony 1638 PPL 1,09 4.39 23.8 21.9 _Arsenic 1638 ligl- 6.5 1

. 34.9 142 69.3. C.admitnn 163S ligl-

. ND (0.500) ND (0.500) 1.32 1.14 Cammium. 1638 l'gl- ND (4.00) 13,5 L 204 4.&I L Copp& 163S ligl- 1...3 -.7 - . 1.49 5.47 2.93 Lead. 163S 1, 1 g 1 - ND (0.250) 0.490 0_5E0 0

. 420 Iferctny 163.1E itgl_ 0,00511 0.00157 U. 212 0.00125 1:licke1 1638 itg-L 10..7 1-7D (5...X) 1 L0 10.7 Selenium 1635 14 1 3.74 17.1 191 45,3 !] i tm 1635 ligt 1,32: 1.46 1.72 2.84 Zinc 1638 141- 24.2 ND (1.50) 101 5.98 Low-Level Metals - s41 'ed Antimony 1638 ligl- 0.990 4.45 1-7;:-.; 22.4 _ArseMc 1638 itgL 500 29.0 131 68.9 Cadr_inu.n

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### Table ' h Pond Effluent C oncentrations

Anatre Method .

Unit Homer CityEffluent from Beitant Ailk Pond' Vildorm: Creek -

Effluent from Combined Ash Pond' hatchell - Effluent

from Ely,-

. Ash Pond ` _ Cardinal-Effluent

from. Fly Ash Pond ''''' Cla Isicaik; Ammonia As Nirogen c. ,

1 7 .- 7 .,-1 1 / 4 .P; 4500._

.. i F mg.. 0.340 0160 0J50 0.205

- ... , :iitateNir:tte r_

. 70 7 -N l';0 2 -11',, 35,3.2 ilk.. 7.°L 37.0 0.23D 0_730 4.73 7 Total Kje

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- ial TIENI) 166-1A....,_ , 1-:D (_5_00) 6.00 ND t5.00) 10.0 Silica Gel Treated HEM. (S&T-HEM) 1664A ingl NA ND ' M) NA ND (4.00) Suite D51640. ing.L 1,290 S0.7 1,110 494 Tow_l DiEsolved Solids (IDS) 2540:C mg1 1.250 281 2,050 673 Tool Phosphom 365.3 mg-T_ 1,09 0.2:70 E 0..200 0.0870 Total Suspended Solids (FSS) '254 D xL 5_00: 1 1 `.0 E 15.0 6.00 Source: [ERG. 200S1; ERG. 200£m; ERG., 20081: ERG, 2008o] Note: EPA used several aualrical aallyn, for metals dart, ' the sampling pro-gram. For the purposes of sampling

- program, EPA desipiated some of the asalyacal methods as 'routine' angi. some of :hem. as. lo3,,'

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. plesen.t

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. blank rout. NA -Not analy

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### TVA-Bull Run Fossil Plant) NPDES Permit TN0005410 Page NOD - 41 of NOD — 42 Attachment 1 BEST MANAGEMENT PRACTICES 1
GENERAL CONDITIONS
For purposes of this part, the terms "pollutant" or "pollutants" refer to any substance listed as toxic under Section 307(a)(1) of the Clean Water Act, oil, as defined in Section 311(a)(1) of the Act, and any substance listed as hazardous under Section 311 of the Act. The permittee shall develop and implement a Best Management Practices (BMP) plan which prevents, or minimizes the potential for, the release of pollutants (including oil and grease) from ancillary activities, including material storage areas; plant site runoff; in-plant transfer, process and material handling areas; loading and unloading operations, and sludge and waste disposal areas, to the waters of the State of Tennessee through plant site runoff; spillage or leaks; sludge or waste disposal; or drainage from raw material storage. 

### GENERAL REQUIREMENTS
The BMP program shall:

1. Be documented in narrative form, and shall include any necessary plot plans, drawings, or maps;

2. Establish specific objectives for the control of toxic and hazardous pollutants:

a. Each facility component or system shall be examined for its potential for causing a release of

significant amounts of toxic or hazardous pollutants to waters of the State of Tennessee due to equipment failure, improper operation, natural phenomena such as rain or snowfall, etc.;

b. Where experience indicates a reasonable potential for equipment failure (e.g., a tank overflow or

leakage), natural condition (e.g., precipitation), or other circumstances to result in significant amounts of toxic or hazardous pollutants reaching surface waters, the plan should include a prediction of the direction, rate of flow, and total quantity of toxic or hazardous pollutants which could be discharged from the facility as a result of each condition or circumstance;

3. Establish specific best management practices to meet the objectives identified under section B.2. contained herein, addressing each component or system capable of causing a release of significant amounts of toxic or hazardous pollutants to the waters of the State of Tennessee;

4. The BMP program:

a. May reflect requirements for Spill Prevention Control and Countetuteasure (SPCC) plans under

section 311 of the Act and Title 40 CFR part 112 and may incorporate any part of such plans into the BMP program by reference;

b. Shall assure the proper management of solid and hazardous waste in accordance with regulations

promulgated under the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act of 1976 (RCRA) (40 U.S.C. §6901, et. seq.). Management practices required under RCRA regulations shall be expressly incorporated into the BMP program; and,

c. Shall address the following points for the ancillary activities listed in section A.1.:

i. Statement of policy;

Note: Additional technical information on BMPs and the elements of a BMP program is contained in EPA publications entitled "Guidance Manual for Developing Best Management Practices (BMP)" (EPA 833-B-93-004) and "Stormwater Management for Industrial Activities: Developing Pollution Prevention Plans and Best Management Practices" (EPA 832-R-92-006).

### TVA-Bull Run Fossil Plant) NPDES Permit TN0005410 Page NOD - 42 of NOD — 42
ii. Spill Control Committee: responsible for BMP program implementation and subsequent review and updating; iii. Material inventory: identification of all sources and quantities of toxic and hazardous substances handled or produced, including plant drawings and plot plans, materials flow diagrams, physical, chemical, toxicological, and health information on toxic and hazardous substances, and investigation and evaluation of new materials; iv. Material compatibility: evaluation of process changes or revisions for materials compatibility, review of properties of chemicals handled and materials of construction, evaluation of means of chemical disposal and incompatibility, cleansing of vessels and transfer lines, and use of proper coatings and cathodic protection on buried pipelines if required;
v. Employee training: meetings to be held at frequent intervals, spill drills, adequate job training, transmission of information on past spills and causes, informing employees of BMP program components, training in cleanup procedures, and review and interface with safety program; vi. Reporting and notification procedures: maintenance of records of spills through formal reports for internal review, notification as required by law to governmental and environmental agencies in the event of a spill, and procedures for notifying the appropriate plant personnel; vii. Visual inspections: routine inspections with visual observations of storage facilities, transfer pipelines, and loading and unloading areas, detailed inspections of pipes, pumps, valves, fittings, tank corrosion, tank support and foundation deterioration, etc.; viii. Preventive maintenance: identification of equipment and systems to which the preventive maintenance program should apply, periodic inspection and testing of such equipment and systems, appropriate adjustment, repair, or replacement of parts, and maintenance of preventive maintenance records; ix. Good housekeeping: neat and orderly storage of chemicals, prompt removal of small spillage, regular garbage pickup, maintenance of dry and clean floors, proper pathways and walkways, minimum accumulation of liquid and solid chemicals on the ground or floor in a building, and stimulation of employee interest in good housekeeping;
x. Security: plant patrols, fencing, good lighting, traffic control, controlled access where appropriate, visitor passes, locked entrances, locks on drain valves and pumps for chemical storage tanks, and television monitoring.

The permittee shall maintain the BMP plan at the facility and shall make the plan available to the permit issuing authority upon request. 

### BMP PLAN MODIFICATION
The permittee shall amend the BMP plan whenever there is a change in the facility or change in the operation of the facility, which materially increases the potential for the ancillary activities to result in a discharge of significant amounts of pollutants. 

### MODIFICATION FOR INEFFECTIVENESS
If the BMP plan proves to be ineffective in achieving the general objective of preventing the release of significant amounts of pollutants to surface waters and the specific objectives and requirements under section B, the permit shall be subject to modification pursuant to 40 CFR 122.62 or 122.63 to incorporate revised BMP requirements. Any such permit modification shall be subject to review in accordance with the procedures for permit appeals set forth in accordance with 69-3-110, Tennessee Code Annotated.

### TVA-Bull Run Fossil Plant) NPDES Permit TN0005410 Page NOD - 43 of NOD - 42

Final Determination:

DETERMINATION It is the determination of the division that NPDES Permit No.TN0005410 be issued to the Tennessee Valley Authority's Bull Run Fossil Plant.

Vojin Janjic Manager, Permit Section Date TN Division of Water Pollution Control

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-1 of R-43 

## RATIONALE, JANUARY 2010
TVA Bull Run Fossil Plant (BRF) NPDES PERMIT NO. TN0005410 Bull Run, Anderson County, Tennessee
Permit Writer: Mr. Bob Alexander I. DISCHARGER

TVA - Bull Run Fossil Plant (BRF) Oak Ridge, Anderson County, Tennessee Facility-Plant Manager: Mr. J. Scott Hambrick 865-945-7212 Corporate Contact: Ms. Lindy P. Johnson Manager of water Permitting and Compliance-TVA (423) 751-3361
Nature of Business: Fossil fueled steam-electric power generating plant. SIC Code(s): 4911 Industrial Classification: Primary Discharger Rating: Major

II. PERMIT STATUS

Issued November 30, 2007 Last modified November 30, 2007 Expired March 30, 2008 Application for renewal received August 25, 2007

Watershed Scheduling Environmental Field Office: Knoxville Primary Longitude: -84.154167 Primary Latitude: 36.000000 Hydrocode: 6010207019 Watershed Group: 3 Watershed Identification: Clinch-Lower Target Reissuance Year: 2013

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-2 of R-43
III. FACILITY DISCHARGES AND RECEIVING WATERSTVA - Bull Run Fossil Plant (BRF) discharges ash transport water, chemical and nonchemical metal cleaning wastewaters, coal pile runoff, low volume wastes, storm water runoff, miscellaneous equipment cooling and lubricating water from Outfall 001 and Outfall 006 (emergency overflow), main condenser cooling water, miscellaneous equipment cooling and lubricating water and sewage treatment plant effluent from Outfall 002, intake screen backwash water through Outfall 004, and metal cleaning waste water through Outfall 005 to Clinch River at mile 48.0. Discharged wastewater originates from the process of generation of electric power from a fossil-fueled steam-electric plant. The plant has one coal-fired unit with a generating capacity of 950 megawatts. The discharge at Outfall 001 from the ash pond Consists of dry fly ash wash down sump, FD fan cooling water, stack yard sump (pulverizer equipment cooling water, boiler bay floor drain), boiler bilge sump (boiler bay floor drainage), non-chemical metal cleaning wastes (boiler fireside washing, air pre-heater washes, precipitator area sump, ducts washing), ash hopper, economizer, pyrite hopper (ash sluice water), hydroveyors (fly ash pumps), precipitator wash down sump (fly ash sump, water from RO treatment), ash pond / gypsum stacking (dewatering facility, flue gas desulfurization (FGD) wastewater system, FGD detention basin / sump, FGD area runoff / drainage, coal yard drainage basin / sump (fly ash stacking area, coal storage area, yard building dust collector sluice, floor drains, roof drains and sumps, coal tower and rail hopper floor / roof drains, utility building roof I floor drains), main station sump (condenser pit sump inflow, equipment cooling water and leakage, service bay floor drainage, emergency overflow from demineralizer sump, leakage from boiler make-up water and water treatment plant, unwatering sump outside powerhouse pumps 1 and 2, yard runoff, electrical yard runoff, back parking lot runoff, roof drains, ash sluice line low point sump), yard drainage basin sump (demineralizer sump (demineralizer system drains), condensate polisher wastes, reject water treatment plant, stack yard sump (equipment cooling water, floor washing wastes), ammonia facility retention pond, ash sluice line low point sump (yard runoff, back parking lot runoff, electrical yard runoff, runoff coal yard pumping basin (coal storage area, fly ash storage area), runoff from ash stacking area, treated metal cleaning waste water (Internal Monitoring Point 005), and direct precipitation on ash pond through Outfall 001; main condenser cooling water (CCW), miscellaneous equipment cooling and lubricating water, and roof drains through Outfall 002; intake screen backwash, discharged to Clinch River via Outfall 004 to cooling water channel.. Treatment in the ash pond of Flue Gas Desulfurization wastewater has been in operation since 2007-8. The discharge at Outfall 002 consists of main condenser cooling water (CCW), miscellaneous equipment cooling and lubricating water, and roof drains. The discharge at Outfall 004 is a comparatively minor waste stream from an intake screen backwash, discharged to Clinch River via condenser cooling water channel. Internal Monitoring Point 005 (Outfall 005 in the submitted application materials and the previous permit) has been designated as the compliance point to verify compliance with 40 CFR effluent limitations for metal cleaning wastes. Effluent stream discharged from Internal Monitoring Point 005 is eventually discharged into the Clinch River mile 48.0 via Outfall 001. The discharge at IMP 005 consists of boiler chemical cleaning waste, air preheater washing waste, and direct precipitation on metal cleaning waste treatment pond.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-3 of R-43 The only storm water discharges associated with industrial activity authorized by this permit are those discharged through Outfall 001. Storm water runoff discharges from the facility not specifically authorized in this permit are covered under the Tennessee Storm Water Multi-Sector General Permit for Industrial Activities, Permit Number TNR053185. Appendix 1 summarizes facility discharges and the receiving stream information for Outfalls 001, 002, 004, and IMP 005.

IV. APPLICABLE EFFLUENT LIMITATIONS GUIDELINES Wastewater discharged from Outfall °Oland 002 is subject to the effluent limitation guidelines contained in 40 CFR, Part 423 for the Steam Electric Power Generating Point Source Category. The Best Practicable Control Technology (BPT) and Best Available Technology Economically Achievable (BAT) limitations for several effluent characteristics are given in sections §423.12 and §423.13, respectively for the following waste streams: fly ash and bottom ash transport water, metal cleaning wastes, once through cooling water (main condensers), cooling tower blow down, coal pile runoff, and low volume waste sources. Low volume waste sources are defined in §423.11(b) as "...wastewater from all sources except those for which specific limitations are otherwise established..." Of particular importance are §423.12(b)(12) and §423.13(h) which state that when regulated waste streams are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in §423.12 and §423.13 attributable to each controlled waste source shall not exceed the specified limitation for that waste source. These sections were interpreted in consideration of a U.S.EPA Memorandum dated August 22, 1985, titled "Guidance for NPDES Permits Issued to Steam Electric Power Plants." Because multiple waste streams of certain CFR limited discharges are combined and treated in the facility ash pond prior to discharge through Outfall 001, the effluent limits set forth in this permit for Outfall 001 are established in accordance with the methods described in the guidance. Appendix 2 lists the applicable effluent limitations guidelines specified in §423.12 and §423.13.

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

VI. HISTORICAL MONITORING AND INSPECTION
During the previous permit term, TVA - Bull Run Fossil Plant (BRF) did not have any appreciable difficulty in meeting effluent limitations as outlined in the previous permit. A summary of the data reported on Discharge Monitoring Report forms during the previous permit term is summarized in Appendix 4. Division personnel from the Nashville Environmental Field Office performed a Compliance Evaluation Inspection (CEI) of the TVA - Bull Run Fossil Plant (BRF). The CEI was performed On December 19, 2008 by Woody Smith and Lanny Bonds. A Compliance Evaluation Inspection is conducted to determine compliance with NPDES permit conditions and check the

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-4 of R-43 operation and maintenance of the equipment used in determining compliance with the permit. The following items were reports as the result of that inspection:
A. There were no operational problems observed at the time of the inspection, however, there were some procedural issues discussed with site personnel at the time of the inspection. B. A copy of the permit was available for review. All documents, laboratory reports, and monitoring reports were available for review and appear to be in line with the requirements of the permit. TMSP monitoring for 2008 was also available for review and appeared to be satisfactory. TVA reported iron as having exceeded the cut off value given in the TMSP. However, the excess was not substantial. This was found at outfalls F11 and F16. TVA has taken action to mitigate the problem. C. At the time of our inspection, we reviewed the DMR and MOR reports for the past twelve months and found no deficiencies or violations of permit limits. TVA Bull Run plant has successfully completed their DMR, QA study 28 and reported on August 29, 2008. On the day of the inspection, the plant appeared in compliance and operational. The effluent being discharged had no visible signs of solids, oil sheen, scum, or foam in the receiving stream from the outfall. D. TVA Bull Run Steam Plant had bio-monitoring testing completed in June 25, 2008, by an outside contractor. The results were available for review and it appeared to be complete and satisfactory. E. On November 25, 2008, TVA completed a calculation on the ash pond volume and freeboard as required by the permit. Based on the calculation, the ash pond has a sufficient volume and freeboard to handle additional water in case of emergency before the dam overtops. F. On June 9, 2008, TVA also performed a complete stability inspection of the ash pond and evaluated the structure's integrity and stability. The inspection finding appeared to be satisfactory.

VII. NEW PERMIT LIMITS AND MONITORING REQUIREMENTS The new permit limits are determined by using Best Professional Judgment (BPJ) through a comparison of any applicable EPA effluent guidelines or State of Tennessee maximum limits per Rule 1200-4-5-.03(2) with the previous permit limits and operational and/or treatability data. The more restrictive requirement from this comparison is checked against the appropriate water quality criteria. The most restrictive limit is used as the new permit limit. Monitoring of flow will be required at all outfalls. Flow shall be reported in Million Gallons per Day (MGD) and monitored at the time of sample collection. Monitoring of flow quantifies the load of pollutants to the stream. Appendix 5 lists all effluent limitations and monitoring requirements included in the new permit. Appendix 5 also provides formulas and detailed procedures for Water Quality Based Effluent Calculations.

A. TVA COAL BYPRODUCT PROCESS CONVERSION
TDEC recognizes that the TVA's Board of Directors decided on August 20, 2009, to convert wet fly-ash and bottom ash handling systems to dry-ash handling systems at Bull Run Fossil Plan and five other coal-burning plants. The decision also included converting gypsum

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-5 of R-43 dewatering facilities and closing ash and gypsum ponds. This renewed permit contains in Part III the provision for a Closure Plan for the existing ash ponds.

B. DIKE INSPECTIONS 1. Inspection Procedures

a. The Bull Run ash pond shall be inspected in accordance with TVA's Reservoir Operations Dam Safety Program criteria and processes. This program is in accordance with the 'Federal Guidelines for Dam Safety' developed by the Federal Emergency Management Agency (FEMA 93). This document directs TVA to perform inspections scheduled on specific intervals and with qualified personnel. The dikes will also be visually inspected daily during operations by site personnel or designee. Impoundments shall be inspected annually by a qualified TVA engineer under the direction of a State-registered professional engineer. Special inspections by qualified personnel shall be done immediately after intense, large or extended rain events (i.e., 10-year storm or equaling or exceeding the design requirements for managing storm water) or within 24 hours after a significant seismic event approaching or exceeding the design event. The reason for this is to validate structural integrity of the structure following an event that could test the design assumptions.
b. (Inspections shall, at a minimum, include observations of dams, dikes and toe areas for erosion, cracks or bulges, subsidence, seepage, wet or soft soil, changes in geometry, the depth and elevation of the impounded water, sediment or slurry, freeboard, changes in vegetation such as overly lush, obstructive vegetation and trees, and any other changes which may indicate a potential compromise to impoundment integrity. The findings of each inspection shall be documented in a written inspection report.

c. Remediation Measures. Within 24 hours of discovering changes that indicate a potential compromise to the structural integrity of the impoundment, the permittee shall begin procedures to remediate the problem. Changes such as significant increases in seepage or seepage carrying sediment may be signs of imminent impoundment failure and should be addressed immediately.
d. Other issues which may have long term impacts on integrity, such as trees growing on the embankment (especially large, dead or tilting trees, with special concern for those at the toes of or within the saturated zones of embankment structures), or vegetation-blocking overflows or spillways, shall be removed according to approved geotechnical engineering practices and instructions. 2. Reporting and Recordkeepinq Requirements for Impoundments

a. Imminent impoundment failure conditions should be reported immediately to the Anderson County Emergency Management Agency, who will report to TEMA and TDEC.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-6 of R-43

b. Within 5 days of discovering any changes in the impoundment that indicate a potential compromise to the structural integrity of the dike (e.g., significant changes in seeps, boils, bulges, or cracks), the permittee must notify the division in writing describing the findings of the inspection, corrective measures taken, and expected outcomes. Failure to do so will be a violation of this permit.

c. The permittee shall submit an annual report to the division summarizing findings of all monitoring activities, inspections, and remediation measures pertaining to the structural integrity, design, construction, and operation and maintenance of all impoundments.
d. The permittee shall maintain records of all impoundment inspection and maintenance activities, including corrective actions made in response to inspections and all other activities undertaken to repair or maintain the impoundment. All records shall be kept on site and made available to State or Federal inspectors upon request.

e. All pertinent impoundment permits, design, construction, operation, and maintenance information, including but not limited to: plans, geotechnical and structural integrity studies, copies of permits, associated certifications by qualified, State-registered professional engineer, and regulatory approvals, shall be kept on site and made available to State or Federal inspectors upon request. 3. Permit Re-opener Requirement The Director may re-open this permit to incorporate more stringent requirements or any applicable standards pertaining to the operation and maintenance of coal combustion waste impoundments.

C. ASH POND VOLUME Beginning on the effective date of this permit, the permittee shall provide and maintain a minimum free water volume in the ash pond of 16.226 40.5 million gallons.as-eaTeulated4R Appendix 5. As needed, the permittee shall remove settled material from the pond, or otherwise enlarge the available storage capacity in order to maintain the required minimum volume. The permittee shall certify annually that the required volume is maintained and shall submit the report to the Division with the monthly DMR once per year. Certification shall be based upon physical surveys conducted every two years and estimates of ash volumes generated/removed in the intervening years. TVA is conducting inspection and repairs to the ash pond dike at the time of this writing. TDEC reviewed and approved the TVA request for changes to the slope of the gypsum stack 64aei and sluice ditch, regarding benches and ditches near the bottom ash stack, excavating the sediment pond and replacing outlet/water controls structures, and inspecting and repairing the existing ash pond dikes. Work is scheduled to be completed in June 2010 August 2010 (due to delay caused by the weather).

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-7 of R-43

In order to complete the work, TVA will temporarily lower the FWV water level in the ash pond by four feet and gradually raise it to normal levels upon completion. In approving the request, TDEC required the Total Suspended Solids monitoring at Outfall 001 be increased from monthly to weekly.

F. USE OF TOXIC CHEMICALS
The permittee shall practice due diligence in evaluating any material that could potentially be discharged via the NPDES outfalls. The permittee shall evaluate the following:
1. Name and general composition of the chemical, 2. Frequency of use, 3. Quantities to be used, 4. Proposed discharge concentrations, 5. Existing 96-hour LC50 toxicity data (including laboratory reports if available) for available aquatic species, 6. Product data sheet, and 7. Product label or copy of the product label. Discharge of any product registered under the Federal Insecticide, Fungicide, and Rodenticide Act to any waste stream which may ultimately be released to lakes, rivers, streams, or other surface waters of the State is prohibited unless authorized in writing by the Division. This requirement is not applicable to products used for lawn and agricultural purposes. This requirement is also not applicable to herbicides used in accordance with labeled instructions and any applicable State permit. Discharge of chlorine from the use of chlorine gas, sodium hypochlorite, or other similar compounds for disinfection in plant potable and service water systems and in sewage treatment is authorized as are similar compounds in once-through cooling water.

G. MACROINVERTEBRATE CONTROL MEASURES The permittee shall submit a plan to the Division if biocides are to be used for macroinvertebrate control at the site. If this is implemented at this facility, the permittee will submit a plan to the Division describing the macroinvertebrate controls to be utilized, material feed rates, and proposed monitoring schedule to verify that effluent limitations are being met and water quality is being protected. Use of biocides may warrant modification of this permit to include additional monitoring or permit limitations.

H. RE-ROUTING FLOWS FOR MAINTENANCE PURPOSES The permittee shall be allowed to re-route flows past normal monitoring points as a temporary measure for maintenance activities. However, such re-routing must be done in such a way that permit limitations are still being met in the receiving waters and compliance with permit limitations is monitored and reported on the DMR's for the re-routed flows. The receiving waters must be the same for the re-routed flows as for the normal discharges.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410

Page R-8 of R-43
I. HEAVY METALS MONITORING
The permittee shall monitor heavy metals at the West Knox District Intake on semiannual basis to ensure this source will not exceed Drinking Water Standards. Heavy metals shall not be discharged in concentrations which cause intake concentrations in the West Knox Utility District Intake to exceed the following limitations at any time:
Arsenic : 0.05 mg/I Lead :
. 0.015 mg/I Cadmium : 0.005 mg/I Mercury : 0.002 mg/I Chromium : 0.1 mg/I Selenium : 0.05 mg/I The permittee shall certify annually that the required intake concentrations are maintained and shall submit the report to the Division with the monthly DMR once per year.

J. PROCEDURES FOR WATER QUALITY BASED EFFLUENT STANDARDS
The procedure used to calculate the allowable instream concentrations for permit limitations is shown in Appendix 5. Should monitoring for a particular pollutant indicate that the pollutant is not present (i.e., consistently below detection level), then the division may drop the monitoring requirements in the reissued permit. Procedures for calculations consider background conditions, chronic and acute water quality criteria, and critical low streamflow in a spreadsheet which calculates a mass balance. The calculated chronic water quality effluent concentrations required for Fish and Aquatic Life are compared to the Human Health criteria in order to determine the most stringent chronic permit limitations. These water quality based limits should then be compared to any technology based (CFR or Tennessee "Rules") effluent limitations, and/or any previous permit limitations, for final determination of the permit limits, as shown in Appendix 5.

K. EFFLUENT REQUIREMENTS FOR OUTFALL 001, ASH POND 1. BIOMONITORING REQUIREMENTS, CHRONIC Based on the results of biomonitoring for the effluent discharged through Outfall 001 in the period of 1994-2006 (see permit application), the division has determined that reasonable potential to exceed narrative water quality standards has not been demonstrated. Therefore, the whole effluent toxicity (WET) limitation at Outfall 001 will not be required in the proposed permit. However, in accordance with EPA recommendations in the Technical Support Document for Water Quality Based Toxics Control (TSD), the permittee will be required to conduct chronic toxicity tests on a "report only" basis. Monitoring frequency will be once during the final 18 months of the new permit term, and the sample type will be flow-proportionate composite. The details regarding dilution series (based on the dilution factor of 6.8, see table below) and biomonitoring methodology can be found in Part III of the permit.

### Stream Is Source of Effluent Outfall 001

Strea Flow Wastewater

Flow Tota

Flow [MGD] [MGD] [MGD] 129.3 19.037 129.3 DF 6.8 IC25 › IWC 14.7

...•••••-



### TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410

Page R-9 of R-43

2. AMMONIA NITROGEN
Selective Non-Catalytic Reduction (SNCR) equipment is used at BRF to lower nitrogen oxide stack emissions, as mandated by the Tennessee Air Quality Board. Installation and operation of the equipment, which involves injection of ammonia nitrogen into the process, has been underway prior to the previous permit. Wastewater volume of 4-977 18.7 MGD discharged from Outfall 001 in the renewal application is only marginally different from the previous permit of 17 MGD. Although the potential exists for effluent discharged from this outfall to contain increased amounts of ammonia nitrogen, reported concentrations of intake and effluent do not show substantial differences of 0.1 mg/l and 0.2 mg/I, respectively — see next page. To assess the potential for ammonia toxicity in the receiving stream, TDEC uses a spreadsheet calculation which considers stream pH and temperature, as shown below. These calculations indicate the allowable effluent concentration of 11 mg/I would be required to protect water quality. Accordingly, the renewed permit shall continue monitoring only at Outfall 001 for ammonia. Monitoring, on a report basis, will include inflow (sampled at the skimmer wall or at a comparable location) and effluent from Outfall 001. The net discharge will be calculated and reported. If a calculated value for net addition of ammonia as nitrogen exceeds an action concentration value of 1.0 mg/L, the permittee shall investigate source(s) of ammonia, and proceed with a corrective action(s), if necessary. Furthermore, EFO Nashvillc Knoxville shall be notified within 24 hours from the time the permittee receives results indicating that an action value of 0.45 mg/L was exceeded. Monitoring will be performed on a monthly basis, using grab samples.

### Bull Run Fossil

Ili 5 

### SN001 and Plant-intake- Nitrogen,AmmeniaTotal

5/20006 5/2/2007 5/2/2008 5/2/2009 Plant intz ke -D5N001 3 ! TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-10 of R-43

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-11 of R-43

Ammonia as Nitrogen Calculations
The State utilizes the EPA document, 1999 Update to Ambient Water Quality Criteria for Ammonia and assumed temperatures of 25°C and 15°C and stream pH of 8 to derive an allowable instream protection value. A mass balance with plant and stream flows and this allowable value determines the monthly average permit limit. Seasonal limits may also be allowed due to ambient temperature variations between the summer and winter seasons.
East TN- 25°C, 15°C A pH value of 7.8 (instead of historically used 7.5) was chosen for two Middle TN- 27°C, 17°C reasons: 1.) ambient monitoring in east TN showed that a pH often West TN- 30°C, 20°C exceeds 7.5, and is up to 7.8 is the 10-year mean 2.) this assumption is more conservative.

Winter Summer Temp (°C)= 15 Temp (°C)= 25 pH° 7.8 pH= 7.8 Min (2.85, 1.45°10^ 2.76 Min (2.85, 1.45°10^ 1.45

0.028°(25-T)) 2.85 0.028125-T)) 2.85

2.76 1.45

CCC= 3.09 CCC= 1.62
CCC - Contionuous Chronic Criterion Allowable instream NH3 concentration [mg/1]

where: 129 Critial Low Flow [MGD] (7010 value)

0.1 Background Ammonnia Concentration [mg/L] 18.9 WWTP Design Flow or long-term average flow [MGD]
Therefore, the Allowable Effluent Concentrations and corresponding Amounts in winter and summer are:

Winter Summer Concentration [mg/L] 23.46 Concentration fmg/L] 11.987
Amount [lb/day] 3697.8 Amount [lb/day] 1889.5

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-12 of R-43

3. OUTFALL 001 - ASH POND DISCHARGE OF METALS 40 CFR, §122.44(d)(1)(iii) states that effluent limits must be specified for an individual pollutant when it is determined that "a discharge causes, has the reasonable potential to cause, or contributes to an in-stream excursion above the allowable ambient concentration of a State numeric criteria within a State water quality standard for an individual pollutant". The permit application indicates that a number of metals are believed to be present in the ash pond discharge. For each of these metals a comparison was made of the effluent concentration as reported on DMRs and the permit application, with calculated limits based on State of Tennessee water quality criteria (APPENDIX 5d) or maximum limits per Rule 1200-4-5-.10
Spreadsheet calculations are shown below utilizing the procedures described earlier for determining water quality-based effluent limits. Specific factors used in these calculations include: • stream background concentrations per the TVA permit application reported values from Bull Run intake monitoring, and

• hardness value of 145 mg/I from the TDEC upstream ambient monitoring station at mile 66

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-13 of R-43

1 ‘;

FACILITY: PERMIT #: TVA - Buil Run Fossil Plant

TN0005410

Stream (1010) Stream

(3005) Waste

Flow Ttl. Susp.

Solids Hardness

(as CaCO3) Stream

Allocation [MOD] [MGDI [MGD] [mgill [m0/ 1 ] 1%1 129.300 424.600 19.037 10 145 90 1 2 1 3 4 5 6 1 7 1 8 Stream Bckgmd. Conc." Fish/Aqua. Life

Water Quality Criteria Effluent Fraction Dissolved Fish & Aquatic Life Water Quality Criteria (1010)

In-Stream Allowable Calc. Effluent Concentration EFFLUENT CHARACTERISTIC Chronic Acute Chronic Acute Chronic Acute 1 1

- 1 8/ 1 1 [ugrI] [ug/I] [Fraction] [ug/I] Iughll lug/I1 [ugh] Arsenic 2.50 150 340 1.000 150.00 340.00 1036.6 2369.1 Cadmium * 2.50 1.357 5.537 0.193 7.04 28.72 34.1 186.2 Copper * 3.00 15.59 24.15 0.218 71.54 110.80 483.3 758.7 Lead * 1.60 3.76 96.55 0.143 26.22 672.87 174.1 4708.9 Silver * 2.50 NA 6.537 0.850 NA 7.69 NA 38.6 Nickel * 13.00 215.25 1938.20 0.206 1046.14 9419.74 7256.9 65979.6 Mercury, (T) *** 0.006 0.700 1.400 1.000 ' 0.700 1.400 4.87 9.8 Chromium (T)*"* 0.50 74.00 570.00 1.000 74.000 570.000 515.9 3994.3 Selenium ***** 0.50 5.00 20.00 1.000 5.000 20.000 32.0 137.2

The Fish & Aquatic Life and calculated effluent
In cases where the
watershed. than toxicity.
2C
30Q5 flow. 

## r 9 10 11 12 1 13 14 Human Health Wate Quality Criteria (3005) In-Stream Criteria Ca[c. Effluent Concentration EFFLUENT CHARACTERISTIC Organisms VatelOrganisnff DWS Organisms %later/Organism: DWS [uWI] [ugll] [ugri] [ug/l] [ug/I] [ug/I]
159.6 Arsenic 10.0 10.0 10.0 46.3 159.6 Cadmium * NA NA 5.0 NA NA 54.7 Copper* NA N/A NA NA NA NA Lead * NA NA 5.0 NA NA 72.8 Silver " NA NA 100.0 NA NA 2047.2 Nickel" 4600.0 610.0 100.0 96217.3 12532.9 1836.4 Mercury, (T) *** 0.051 0.05 2.0 0.949 0.928 41.8 Chromium (T)**" NA NA 100.0 NA NA 2087.3 Selenium NA NA 5.0 NA NA 104.9

* Denotes metals for which Fish & Aquatic Life Criteria are expressed as a function of total hardness. criteria for this metal are in the dissolved form at laboratory conditions. The in-stream allowab l e criteria concentrations are in the total recoverable form. ** Stream background concentrations are taken from Outfall 002 intake sample on the permit application. background concentration was reported as less than a value, one halt of the value was used. A background level of 0.006 ug/L based on reference stream monitoring by DOE in the Lower C linch *** The chronic criterion for mercury is not converted to dissolved, since it is based on fish tissue data rather   The criteria for this parameter are in the total recoverable form. ** **" Stream background concentration for selenium is half of the intake value of <0.001 mg/I reported on Form

and for arsenic is half of the intake value of <.005 mg/I. NOTE: Water Quality criteria for stream use classifications other than Fish & Aquatic Life are based on the

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-14 of R-43 The comparison table shown below illustrates the relationship between calculated effluent requirements for metals, TN water quality criteria, and reported concentrations from Outfall 001 on Discharge Monitoring Reports.

DETERMINATION OF MONITORING REQUIREMENTS BY COMPARISON OF APPLICABLE EFFLUENT LIMITATIONS

TVA- Bull Run Fossil Plant Outten 001

RDL * DMR Summary** Application Sample Tennessee WQC Water

Quality*** Long Term Average Daily

Maximum Daily

Maximum EFFLUENT CHARACTERISTIC [mg/1] I [mg/I] [mg/I] [mg/I] [mg/I] [mg/I] Cadmium (T) 0.001 0.0004 0.0005 0.0007 0.002 0.06 Chromium (T) 0.001 0.002 0.004 0.0015 0.57 2.09 Copper (T) 0.001 0.0044 0.0057 0.0050 0.013 0.758 Lead (T) 0.001 0.0010 0.0020 0.0020 0.065 0.07 Mercury, (T) 0.0002 0.0002 0.0002 <0.0002 0.00005 0.0009 Silver (T) 0.001 0.0004 0.0010 <0.0005 0.003 0.038 Nickel 0.01 NR NR 0.0085 0.47 1.836 Arsenic 0.001 NR NR 0.011 0.34 0.16 Selenium (T) 0.002 0.0120 0.0280 0.015 0.02 0.1050

* Required Detection Level per State of Tennessee Rule 1200-4-3-.05(8) ** Data reported 2005 - 09.
*** Most stringent applicable water quality based limit. 

### These data illustrate two things: (1) the effluent concentrations necessary to protect water quality in the Clinch River downstream of Outfall 001 as shown in the spreadsheet on the preceding page, and (2) reported effluent concentrations comply with the required water quality based limits.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-15 of R-43 The division has determined that additional monitoring of toxic metals is required in the renewed permit for the Ash Pond discharge. Monitoring frequencies for metals are established as monthly and additional monitoring will be conducted and reported as shown below:

OUTFALL 001 EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY 

### EFFLUENT CHARACTERISTIC AVG. CONC. AVG.

AMT. MAX.

CONC. MAX.

' AMT. MSRMNT. 1

FRQNCY. SAMPLE

TYPE (ug/L) (lb/day) (ug/L) (lb/day) Arsenic (T) N/A 

### N/A report N/A Monthly Grab Cadmium (T) N/A 

### N/A report N/A Monthly Grab Copper (T) N/A N/A report N/A Monthly Grab Lead (T) N/A N/A report N/A Monthly Grab Mercury (T) N/A N/A report N/A Monthly Grab Nickel (T) N/A N/A report N/A Monthly Grab Selenium (T) N/A N/A report N/A Monthly Grab Thallium (T) N/A N/A report N/A Monthly Grab Zinc (T) N/A N/A report N/A Monthly Grab

4. OUTFALL 001 - PH A pH range limit of 6.0 to 9.0 will be retained for the discharge from Outfall 001. This ensures the protection of water quality per certain Tennessee water quality criteria and, likewise, follow the federal guidelines promulgated by the EPA in 40 CFR §423.12(b)(1) which states "The pH of all discharges, except for once through cooling water, shall be in the range of 6.0 to 9.0." The pH monitoring frequency at Outfall 001 will be retained from the previous permit at once per week, and collected by a grab sample.
L. OUTFALL 002 The effluent discharged through Outfall 002 is primarily composed of "once through cooling water" from the main condensers (approximately 546.4 MGD), which is subject to the effluent limitations guidelines contained in §423.12(b)(6) and §423.13(b).

1. BIOMONITORING REQUIREMENTS, CHRONIC Based on the dilution factor and insufficient receiving stream flow for mixing, there is a concern for toxicity effects of the discharge on the receiving stream. Biomonitoring will provide information relative to the toxicity of the discharge. Calculation of toxicity limits is as follows: Qs DF = = Dilution Factor Ow
where Qw is a wastewater flow (Ow = 546.44 MGD) and Qs is a receiving stream low flow (1010 = 129.3 MGD). Please refer to Appendix 1 for details regarding facility discharge and receiving stream. Therefore,

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-16 of R-43
129.3 DF = = 0.24 546.44 Since the calculated dilution factor is less than 100:1, and assuming immediate and complete mixing, protection of the stream from chronic effects requires: 1WC < 1.0 X IC25; or, INHIBITION CONCENTRATION, 25% › IWC Where IWC is lnstream Waste Concentration and is calculated using the following formula: Qw IWC = X 100 = lnstream Waste Concentration Qs

546.44 IWC = X 100 = 422.6 (i.e. 100%) 129.3 Therefore, WET testing will be required on 100% effluent. The toxicity tests specified herein shall be conducted annually and begin no later than ninety (90) days from the commencement date of biocide addition. Toxicity tests shall be conducted only if biocides are added to the once through cooling water. The details regarding biomonitoring methodology can be found in Part Ill of the permit.

M. OUTFALL 004

Intake screen backwash water (approximately 567 mgd) may be discharged through Outfall 004 without limitations or monitoring requirements. The discharge shall not have a visible oil sheen and reasonable steps shall be taken to prevent the return of unsightly materials to the receiving waters.

N. INTERNAL MONITORING POINT 005

Treated chemical and non-chemical metal cleaning wastes are discharged from Internal Monitoring Point 005, which discharges its effluent via the ash pond Outfall 001 to Clinch River mile 48.0. Due to the additional treatment and dilution provided by the ash pond, compliance with some of the requirements of 40 CFR §423.12(b)(5) and §423.13(e) for facility metal cleaning wastes will be verified at Outfall 001. Since additional treatment for TSS and Oil & Grease is provided in the ash pond, monitoring at Internal Monitoring Point 005 will be required for Flow, Total Copper, and Total Iron only. Such effluent limitations are consistent with monitoring requirements contained in the previous permit. Furthermore, limits specified at Outfall 001 (ash pond discharge) for TSS and Oil & Grease are more stringent than those specified in §423.12(b)(5) and will therefore assure compliance with these regulations. Considering the nature of an effluent collection and discharge system, the sample type for Total Copper and Total Iron will be grab. The permittee will be required to monitor

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-17 of R-43 discharges through IMP005 only when metal cleaning operations or other process wastewater generating activities occur.

0. USE OF TREATED EFFLUENT FOR DUST CONTROL ON ROADS TVA's September 24, 2007, permit renewal application requested authorization to use treated ash pond (Outfall 001) and/or ash dredge cell (future Outfall 011) wastewater for watering plant roadways for control of dusting and as a beneficial use of the water that would be discharged to the receiving stream. TVA requests inclusion of this authorization in the permit. The division disagrees with this practice, as it can contribute to long-term release in offsite particulate dust containing metals. We recommend TVA consider other dust control options in consultation with the TDEC Division of Air Pollution Control. Accordingly, the division is not approving this request.

P. 316(A) — COMPLIANCE WITH SECTION 316, CLEAN WATER ACT 1. 316(A) POTENTIAL THERMAL EFFECTS ON A BALANCED INDIGENOUS POPULATION OF AQUATIC LIFE
Section 316(a) of the Clean Water Act allows point-source discharges of heated water to exceed State water quality thermal criteria based on demonstrating maintenance of "Balanced Indigenous Populations" (BIP) of aquatic life. Bull Run Fossil is operating under a 316(a) alternate thermal variance that has been administratively continued with each permit renewal based on studies conducted in the mid 1970's. The requirement for conducting 316(a) studies in TN comes from EPA Region IV guidance to the States requiring future variance requests be granted on new data generated to show aquatic communities meet the BIP standard. In 2001, TDEC approved the TVA program for Reservoir Fish Assemblies Index (RFAI) studies to support the continuation of thermal variances. RFAI data is collected at upstream and downstream stations in Melton Hill Lake on the Clinch River every two years. With the application, TVA submitted data from 2001, 03, and 05 supporting their request for continuation of the 316(a) variance from the previous permit. With the permit renewal application of September 2007, TVA described ecological conditions near Bull Run Fossil Plant as monitored at three locations under their Vital Signs (VS) program. In addition to the fish community, environmental indicators are measured in the VS program for dissolved oxygen, chlorophyll, sediment quality, and benthic macro-invertebrate community. TDEC has reviewed the RFAI fish community data for 2001-2005 and identified no substantial difference in the fish community of the Clinch River between fish upstream and downstream of Bull Run. Fish data for both the upstream and downstream stations are below expectations. The TVA report supports the theory that low water temperatures originating from Norris Dam are the main contributor to lower RFAI values at the station upstream of Bull Run Fossil Plant, since fish community data from the VS program for two downstream stations reflect higher scores than the upstream data.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-18 of R-43 Extensive interagency discussions between TVA, TDEC, and EPA Region 4 have occurred regarding future studies to demonstrate BIP. EPA Region 4 has requested additional information prior to their approval of TDEC renewal of any NPDES permits for fossil plants, in order to evaluate the thermal component and protection and propagation of a BIP. EPA and TVA have agree to revise the existing TVA process for reservoir monitoring in accordance with the following terms: Within 60 days of the permit effective date, the permittee shall prepare and submit for review by the Division a study plan which outlines how the permittee will conduct assessments that will generate information sufficient to support a determination of whether the Bull Run Plant's alternative thermal limit under Section 316(a) can be continued in its next NPDES permit. The proposed study plan shall be designed to supplement information previously provided by the permittee. The permittee shall implement provisions of the plan within 60 days of its approval by the Division In the renewed permit, TDEC will extend the thermal variance, with the condition that TVA will revise the reservoir monitoring approach acceptable to TDEC and EPA Region 4.
2. 316 (B) - COOLING WATER INTAKE STRUCTURE-316(B) 316(b) limitations for this facility are determined to be in compliance based on best professional judgment in accordance with 40 CFR 401.14 and 122.43. This permit may be reopened to address compliance with 316(b) requirements upon issuance of a new rule or fina guidance by EPA. This permit, TN0005410, had been previously issued by EPA under the federal NPDES permit program. In those previous permits the facility was deemed to be in compliance with the Clean Water Act Regulations, Establishing Requirements for Cooling Water Intake Structures at Phase II Existing Facilities. This regulation is also referred to as the "316(b) rule". Previous and current compliance with the rule have been and continue to be based on best professional judgment (BPJ) in accordance with Title 40 CFR 401.14 and 122.43. In 2007, during review of the draft permit addressing TVA's request for permit modification of the 316(b) language, EPA Region 4 suggested the division add language to the rationale of the permit to better detail the events supporting this modification. As it is still relevant to this permit renewal, we have included background information regarding the 2007 recent Court actions relating to the 316(b) rule: On February 16, 2004, EPA took final action on regulations governing cooling water intake structures at certain existing power producing facilities under section 316(b) of the Clean Water Act (Phase II rule). 69 FR 41576 (July 9, 2004). The final Phase II rule applies to existing facilities that are point sources that, as their primary activity, both generate and transmit electric power or generate electric power for sale to another entity for transmission; use or propose to use cooling water intake structures with a total design intake flow of 50 MGD or more to withdraw cooling water from waters of the United States; and use at least 25 percent of the water withdrawn exclusively for cooling purposes (see 40 CFR 125.91). Under the Phase II rule, EPA established performance standards for the reduction of impingement mortality and entrainment (see 40 CFR 125.94). The performance standards consist of ranges of reductions in impingement mortality and/or entrainment.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-19 of R-43 These performance standards were determined to reflect the Best Technology Available (BTA) for minimizing adverse environmental impacts at facilities covered by the Phase 11 rule. These regulations were challenged by industry and environmental stakeholders. On judicial review, the Second Circuit decision (Riverkeeper, Inc. v. EPA, 475 F.3d 83, (2d Cir., 2007)) remanded several provisions of the Phase ll rule on various grounds. The provisions remanded to EPA include:

• EPA's determination of the BTA under section 316(b); • The rule's performance standard ranges; • The cost-cost and cost-benefit compliance alternatives; • The Technology Installation and Operation Plan provision; • The restoration provision; and • The "independent supplier" provision. With several significant provisions of the Phase II rule affected by the decision, and with the need to provide timely direction to Stakeholders about the continuing application of the Phase II rule, EPA's Assistant Administrator for Water issued a memorandum on March 20, 2007, which announced EPA's intention to suspend the Phase II rule. This memorandum also discussed the anticipated issuance of [this] Federal Register suspension document. The formal suspension of the rule was published in the Federal Register: July 9, 2007 (Volume 72, Number 130)][Rules and Regulations][Page 37107-371091, and is available from the Federal Register Online via GPO Access [wais.access.gpo.godDOC1D:frO9N07-31. Upon notice of the suspension of this rule, TVA requested to modify and remove only the suspended 316(b) requirements previously issued in this and seven (7) other TVA NPDES permits. The division agreed with the TVA request and modified only those requirements specifically suspended by the EPA, specifically the CDS report. All other permit requirements remained in place as enforceable compliance items as previously permitted and were deemed to remain in compliance with the remainder of the Clean Water Act based on BTA and best professional judgment (BPJ). In January, 2008, TVA submitted biological monitoring data collected in accordance with the permittee's Proposal for Information Collection (PIC) plan as developed under the 316(b) requirements prior to their suspension by EPA on March 20, 2007. This and other information will be used to support evaluation of Best Technology Available during permit reissuance in subsequent years.OUTFALL 001 LONGITUDE 84-09-15 LATITUDE

36-00-00 

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-20 of R-43
APPENDIX 1 FACILITY DISCHARGES AND RECEIVING WATERS

FLOW DISCHARGE SOURCE (MGD) Discharge from Asti pond: 1.6430 Boiler bilge sump 3.1900 Hydroveyers (ash collection) 1.4290 Precipitator washdown sump 0.0052 MCW Chemical treatment pond (IMP 005) 0.0011 Dry 0y ash washdown sump 1.1920 FD tan cooling water 1.1170 Stack yard sump (equipment cooling water) 0.0290 Stack yard sump (floor drainage) 6.8480 Ash sluice water 0.0042 Fly ash silo area sump 0.0780 Demineralizer sump 0.1365 Coal yard drainage basin/sump (fly ash stacking area) 0.1550 Coal yard drainage basinIsump (coal storage area) 0.9716 Coal yard drainage basin/sump (floor/roof drains) -0.0970 Coal yard drainage basin/sump (evaporation) 0.0141 Ash sluice line low point sump (yard runoff) 0.0247 Ash sluice line low point sump (electrical yard runoff) 0.0177 Ash sluice line low point sump (back parking lot runoff) 1.0380 Main station sump (equipment cooling water & leakage 0.0140 Main station sump (service bay floor drainage) 0.0680 Main station sump (plant leakage - boilers) 0.0041 Main station sump (roof drains) 0.0142 Unwatering sumps (yard runoff) 0.5003 Precipitation 0.1180 Evaporation 0.7570 FGD Flows, including runoff 19.0367 TOTAL DISCHARGE Treatment: Settling (1U), Neutralization (2K). RECEIVING STREAM DISCHARGE ROUTE Outfall 001 discharges into Clinch River mile 48.0
STREAM LOW FLOW (CFS) * 701 1010 3002 290. 200.0 657.0 (MGD) 1 187.4 129.3 424.6

STREAM USE CLASSIFICATIONS (WATER QUALITY) RSH FEOREATION IRRIGATION LW&W DOMESTIC X X X X X INDUSTRIAL NAVIGATION x x

Reference: Flow Duration and Low Flows of Tennessee Streams th rough 1992 by George S. Law and Jess D. Weaver. Water Resources Investigations Report 95-4293 prepared by the U.S. Geological Survey in Cooperation with the Tennessee Department of Environment and Conservation and the Tennessee Valley Authority. Nashville, Tennessee, 1996, p. 51. Station number 03533000: flow regulated by Norris Dam.OUTFALL 002 LONGITUDE 84-09-30 LATITUDE

36-01-00

FLOW DISCHARGE SOURCE (MGD) Condenser cooling water discharges: 0.0040 Roof drains 17.8550 Equipment cooling water 539.9420 Condenser cooling water 0.0270 Intake screen backwash (Outfall 004) -11.3880 Withdrawal for ash disposal

546.4400 TOTAL DISCHARGE RECEIVING STREAM DISCHARGE ROUTE duffel! 002 discharges into Clinch River mile 48.0

STREAM LOW 7010 1Q10 3002 FLOW (CFS) * 290.0 200.0 NA (MGD) I 187.4 129.3 NA

STREAM USE CLASSIFICATIONS (WATER QUALITY) FISH RECREATION IRRIGATION UMW DOMESTIC x x x x x INDUSTRIAL NAVIGATION X X

Treatment Discharge to surface water via condenser cooling water discharge canal (4A). Reference: Flow Duration and Low Flows of Tennessee Streams through 1992 by George S. Law and Jess D. Weaver. Water Resources Investigations Report 95-4293 prepared by the U.S. Geological Survey in Cooperation with the Tennessee Department of Environment and Conservation and the Tennessee Valley Authority. Nashville, Tennessee, 1996, p. 51. Station number 03533000:flow regulated by Norris Dam.

OUTFALL 004 LONGITUDE 84-09-30 LATITUDE

36-01-00
FLOW DISCHARGE

SOURCE (MOD) Raw river water 0.0900 Backwash intake water (approximate)
0.0900 TOTAL DISCHARGE RECEIVING STREAM DISCHARGE ROUTE Outfali 004 discharges into Clinch River mile 48.0 via CCWC
STREAM LOW
FLOW (CFS)* 7010 1Q10 3002 290.0 200.0 NA (MGD) 187.4 129.3 NA
STREAM USE CLASSIFICATIONS (WATER QUALITY) - - FISH RECREATION IRRIGATION LW&W DOMESTIC x x x x x INDUSTRIA L NAVIGATION x x Reference: Flow Du ration and Low Flows of Tennessee Streams through 1992 by George S. Law and Jess D. R Weaver. Water Resources Investigations Report 95-4293 prepared by the U.S. Geological Survey in Cooperation with the Tennessee Department of Environment and Conservation and the Ten nessee Valley Authority. Nashville, Tennessee, 1996, p. 51. Station number 03533000: flow regulated by Norris Dam. 

### TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410 Page R-21 of R-43 

## APPENDIX 1 (continued)OUTFALL 005 LONGITUDE 84.09-45 LATITUDE

36-01-45 

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-22 of R-43


## APPENDIX 1 (continued)

FLOW DISCHARGE SOURCE (MGD) to 001 0.0606 Boiler chemical cleaning 0.0040 Air preheater washer 0.0041 Precipitation -0.0035 Evaporation

0.0052 I TOTAL DISCHARGE RECEIVING STREAM DISCHARGE ROUTE Outfall 005 discharges into Clinch River mile 48.0 (via Outfall 001)
STREAM LOW 7010 1Q10 3002 FLOW (CFS) * 290.0 200.0 NA (MGD) r 187.4 I 129.3 NA

STREAM USE CLASSIFICATIONS (WATER QUALITY) RS H RE-CREATION IRRIGATION LW&W DOMESTIC x x x x x INDUSTRIAL NAVIGATION X X

Treatment in a 8.65 acre pond: pH adjustment, aeration 2B), chemical precipitation of metals (2C), settling (1 U), and neutralization (in ash pond)(2K) Reference: Flow Duration and Low Flows of Tennessee Streams through 1992 by George S. Law and Jess D. Weaver. Water Resources Investigations Report 95-4293 prepared by the U.S. Geological Survey in Cooperation with th e Tennessee Department of Environment and Conservation and the Tennessee Valley Authority. Nashville, Tennessee, 1996, p. 51. Station number 03533000: flow regulated by Norris Dam.TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-23 of R-43
APPENDIX 2 APPLICABLE EFFLUENT LIMITATIONS GUIDELINES from Title 40, CFR Part §423.12 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). 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:



### Pollutant or pollutant property BPT 

### effluent limitations

Maximum for any 1 day (mg/1) Average 

### of daily values for 30 consecutive days shall not exceed (mg/1) 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:



### Pollutant or pollutant property BPT 

### effluent limitations

Maximum for any 1 day (mg/1) Average of daily values for 30 consecutive days shall not exceed (mg/1) TSS 100.0 30.0 f 

### Oil and grease 20.0 15.01TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-24 of R-43
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:



### Pollutant or pollutant property BPT effluent limitations

Maximum for any 1 day (mg/1) Average 

### of daily values for 30 consecutive days 

### shall not exceed (mg/1) 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 concentration listed in the following table:



### Pollutant or pollutant property BPT effluent limitations Maximum concentration

(mg/1) Average 

### concentration (mg/I)
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:



### Pollutant or pollutant property BPT effluent limitations Maximum concentration Average 

### concentration (mg/1) (mg/1) 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:



### Pollutant or pollutant property 

### BPT effluent limitations Maximum concentration for any time (mg/1) TSS 50BAT Effluent Limitations Pollutant or pollutant property Maximum concentration (mg/I) Total residual chlorine 0.20 TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410 Page R-25 of R-43 (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 hour rainfall event shall not be subject to the limitations in paragraph (b)(9) of this section. (11) 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 (7) of this section. Concentration limitations shall be those concentrations specified in this section. (12) In the event that waste streams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (b)(1) through (11) of this section attributable to each controlled waste source shall not exceed the specified limitations for that waste source. [47 FR 52304, Nov. 19, 1982, as amended at 48 FR 31404, July 8, 1983]

§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:

(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:TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-26 of R-43

Pollutant or pollutant property BAT effluent limitations Maximum concentration

(mg/I) Average concentration (mg/I) 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:

Pollutant or pollutant property BAT effluent limitations Maximum concentration (mg/I) Average concentration (mg/I) Free available chlorine 0.5 0.2

Pollutant or pollutant property Maximum for any 1 day -(mg/1) Average of daily values for 30

consecutive days shall not exceed =(mg/1) The 126 priority pollutants (Appendix A) contained in chemicals added for cooling tower maintenance, except: ( 1 ) ( 1 )

Chromium, total 0.2 0.2 Zinc, total 1.0 1.0

1 No 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:
Pollutant or BAT effluent limitationsTVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-27 of R-43
pollutant property Maximum for any 1 day (mg/I) Average of daily values for 30 consecutive days shall not exceed -(mg/I) Copper, total 1.0 1.0 Iron, total 1.0 1.0 (f) [Reserved—Nonchemical Metal Cleaning Wastes]. (g) 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) through (e) of this section. Concentration limitations shall be those concentrations specified in this section. (h) In the event that waste streams from various sources are combined for treatment or discharge, the quantity of each pollutant or pollutant property controlled in paragraphs (a) through (g) 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 (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 paragrdph (d)(3) were approved under control number 2040- 0033.) [47 FR 52304, Nov. 19, 1982, as amended at 48 FR 31404, July 8, 1983]

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-28 of R-43
APPENDIX 3 PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS

PERMIT LIMITS

OUTFALLS 001

1 --- EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. AMNT. MAX, CONC, MAX. AMNT. MSRMNT. FRQNCY. SAMPLE TYPE (mP,A) (ibiday) OW) (lb/day) FLOW Report (MGD) Report (MGD) * 1/Week Instantaneous pH ** Flange 6.0 - 9.0 1/Week Grab OIL & GREASE 12.0 -- 16.0 -- 1/Month Grab TOTAL SUSPENDED SOLIDS (TSS) 26.0 -- 84.0 -- 1/Month Grab NITROGEN, AMMONIA TOTAL (Plant

Intake) -- -- Report Report 2/Month Grab NITROGEN, AMMONIA TOTAL

(Effluent) - - L Report Report 2/Month Grab NITROGEN, AMMONIA TOTAL (Net

Discharge) -- -- Report "*— Report 2/Month Calculated COPPER,TOTAL -- -- Report -- 1/Year Grab LEAD, TOTAL -- -- Report -- 1/Year Grab MERCURY, TOTAL -- -- Report -- 1/Year Grab SELENIUM, TOTAL -- -- Report -- 1/Year Grab CADMIUM, TOTAL -- -- Report -- 1/Year Grab CHROMIUM, TOTAL -- -- Report -- 1/Year Grab IRON, TOTAL -- -- Report -- 1/Year Grab MANGANESE, TOTAL -- -- Report -- 1/Year Grab SILVER, TOTAL -- -- Report -- 1/Year Grab IC25 Survival, Reproduction, & Growth in 100% Effluent Annually Grab ***
Note: The permittee shall take reasonable steps to prevent discharge of cenospheres other than in trace amounts from the outfall. * Flow shall be reported in Million Gallons pe Day (MGD). pH analyses shall be performed within fifteen (15) minutes of sample collection. *** See Part Ill for methodology. -- If a calculated value for net addition of ammonia as nitrogen exceeds an action concentration value of 1.0 mg/L, the permittee should investigate source(s) of ammonia, and proceed with a corrective action(s), if necessary. Furthermore, EFO - Knoxville shall be notified within 24 hours from the time the permittee receives results indicating that an action value of 1.0 rrig/L was exceeded.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-29 of R-43 APPENDIX 3 (CONTINUED)
PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS

1

shall Outten

of TRC that its MDL In cases

period

Plan PERMIT LIMITS
OUTFALL 002
EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY W DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. AMNT. MAX. CONC. MAX. AMNT. MSRMNT. SAMPLE TYPE (mS 11 ) (1131clay) (rrign) (Ib/day) FRONCY. FLOW Report (MGD) Report (MGD) 1 / Day Estimate' TEMPERATURE, Intake Report -- Report -- 1 / Day Grab TEMPERATURE, Effluent - 31.1°C (88°F) 1 / Day Calculated 2 TOTAL RESIDUAL OXIDANT (reported as chlorine) 3 0.011 -- 0.019 -- 1 / Week 4 Grab
TIME OF CHLORINE ADDITION (minute/day/unit) -- 120 5 1 / Day Log Records IC25 Survival, Reproduction, & Growth in 100% Effluent Once 6 Composite 6

1 Flow shall be estimated from pump logs and reported in Million Gallons per Day (MGD).

2 Intake temperature is measured hourly and reported as the average of the hourly measurements for each day. The daily maximum discharge temperature be calculated for the cooling channel based on the 24-hour average intake temperature, 24-hour average unit load, and the 24-hour average flow through 002.
3 Total Residual Chlorine (TRC) monitoring shall be applicable when chlorine, bromine, or any other oxidants are added. The acceptable methods for analysis are any methods specified in 40 CFR, Part 136. The method detection level (MDL) for TRC shall not exceed 0.05 mg/I unless the permittee demonstrates is higher. The permittee shall retain the documentation that justifies the higher MDL, and shall have that documentation available for review upon request. where the permit limit is less than the MDL, the reporting of TRC at less than the MDL shall be interpreted to constitute compliance with the permit limit.

4 Except for periods of macroinvertebrate control when oxidant addition is required (see Permit - Part Ill), samples shall be taken once at the beginning of the of chlorination for one unit and once every 15 minutes thereafter. At the end of the period of chlorination, one sample shall be taken. Sampling for these oxidants is not required when there is no chlorine/bromine added during that day.

5 Application of a oxidant (bromine/chlorine) beyond the 120 minutes per day will be allowed to facilitate nuisance macroinvertebrate control according to the for such activities described in Permit - Part Ili.
6 See Part Ill for methodology. Toxicity tests shall be performaed only if biocides are added to the cooling water.

PERMIT LIMITS OUTFALL 004 Intake Screen Backwash Water

No numerical limitations or monitoring requirements. The discharge shall not have a visible oil sheen and the permitee shall take reosonable steps to prevent the return of materials collected on the screens to the receiving waters in a way that causes and unattractive condition on the recieving waters.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-30 of R-43 APPENDIX 3 (CONTINUED)
PREVIOUS PERMIT LIMITS AND MONITORING REQUIREMENTS

PERMIT LIMITS I
INTERNAL MONITORING POINT 005
EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. ANNT. MAX. CONC. MAX. ANENT. MSRMNT. FRQNCY. SAMPLE TYPE (mg/I) (]b/day) (mWI) (]b/day) FLOW Report (MGD) * Report (MGD) * 1/Batch Estimate* IRON, TOTAL 1.0 -- 1.0 -- *. Grab COPPER,TOTAL 1.0 -- 1.0 -- ** Grab
Flow shall be reported in Million Gallons per Day (MGD), and shall be estimated based on elevation change. Samples shall be taken at the beginning and end of a discharge event for each batch treated.0.0 5/2/2005

3 0

25

.

20

15 ---

10 5/2/2009 5(2/2008 S/2/2006 5/2/2007

Oil & Grease, mgIL

5/2/200S 5/1/200/ S/2/200b OUTFALL 001 - - 2005 - 09

10.0

9.0

8.0

7.0

6.0

5.0

4..0

0

2.0

1.0

-4—T5S

Total Suspended Solids, mg/I TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410

Page R-31 of R-43

APPENDIX 4 HISTORICAL MONITORING AND INSPECTION• ------- ▪ ----- Oil and Grease, mg/I 0.4

0.35

0.3

0.25 —

0.2

0.15

0.1

0.05

0 10.0

9.0

8.0

7.0

6.0

5.

4.0

3.0

2.0

1.0

0.0 5/2/2005 Grease—

5/2/2009 5/2/2006 5/2/2007 5/2/2008 TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410

Page R-32 of R-43

APPENDIX 4
HISTORICAL MONITORING AND INSPECTION

OUTFALL 001 - - 2005 - 09

1,-, W W. l,0 W w ko r-- r- r--. 1

- ---. N. N. 00 00 00 .0 co oo G. 6 6 6 6 6 6 6 6 6 c, 6 6 6 e, 6 6 c; 6 6 o 6 6 6 6 6 6 0 6 60000000 0 0 060 ID 0 0 00606660 N. N. N. N. N. N. N. N. N f...1 N N. N 0.J ,, .i N ( ,

1 1"..1 NJ r".i N. N. r`. 1 r`

- .1 1 ^, ^, ,_. 1

- -, ----, ....._. -,_ N. -.-__ 1 ,

..... ........ 1....... 4-1 .r, .r1

--., ,--i

.

.-4 ,-, r-I rl ti r r-I - —t —I 1-1 rl e-1rt r

. rt

. — t .rt ,

— I -...„. .'" ,t, ry 4. 00 CO CD N. N. [3

. 10 - CO cy r, N. 0 WI CO Co ..

- 4 r .4 0 LO 03 0 ri rl /...1 ...I ..al r-4 e--I .,I Iron and Manganese0.03

0.025 0.04

- Se 0.035 

### 1\ t v I t, --Ak 4 A ft,

v 

### 1 t., I t, ,0 *,

0.02

0.01

0.005

0 Hg Ph Cu Cr

- Cd TVA-Bull Run Fossil Plant (Rationale)

NPDES Permit TN0005410 Page R-33 of R-43
APPENDIX 4
HISTORICAL MONITORING AND INSPECTION

OUTFALL 001 - - 2005 - 09



### eeee e eegeeeee ,Yry eeee 

### cF3 4 1, $

1

. ti 0 0 0 0 0 „ I: , 1N , t ,, ,,, Various Metals

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-34 of R-43
APPENDIX 5a PROCEDURES FOR DETERMINING WATER QUALITY BASED EFFLUENT LIMITS The following formulas are used to evaluate water quality protection: Cm = 0sCs + QwCw

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

Cw 5 ja,) [Cm (Qs + Ow) - QsCs1

Qw where (S A ) is the percent "Stream Allocation". Calculations for this permit have been done using a standardized worksheet, titled "Water Quality Based Effluent Calculations." Division policy dictates the following procedures in establishing these permit limits:
1. The critical low flow values are determined using USGS data:

Fish and Aquatic Life Protection 7010 - Low flow under natural conditions 1010 - Regulated low flow conditions Other than Fish and Aquatic Life Protection 3002 - Low flow under natural conditions
2. Fish & Aquatic Life water quality criteria for certain Metals are developed through application of hardness dependent equations. These criteria are combined with dissolved fraction methodologies in order to formulate the final effluent concentrations.
3. For criteria that are hardness dependent, chronic and acute concentrations are based on a Hardness of 25 mg/I and Total Suspended Solids (TSS) of 10 mg/I unless STORET or Water Supply intake data substantiate a different value. Minimum and maximum limits on the hardness value used for water quality calculations are 25 mg/I and 400 mg/I respectively. The minimum limit on the TSS value used for water quality calculations is 10 mg/I.
4. Background concentrations are determined from the division database, results of sampling obtained from the permittee, and/or obtained from nearby stream sampling data. If this background data is not sufficient, one-half of the chronic "In-stream Allowable" water quality criteria for fish and aquatic life is used. If the measured background concentration is greater than the chronic "In-stream Allowable" water quality criteria, then the measured background

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-35 of R-43 

## APPENDIX 5a (Continued) concentration is used in lieu of the chronic "In-stream Allowable" water quality criteria for the purpose of calculating the appropriate effluent limitation (Cw). Under these circumstances, and in the event the "stream allocation" is less than 100%, the calculated chronic effluent limitation for fish and aquatic life should be equal to the chronic "In-stream Allowable" water quality criteria. These guidelines should be strictly followed where the industrial source water is not the receiving stream. Where the industrial source water is the receiving stream, and the measured background concentration is greater than the chronic "In-stream Allowable" water quality criteria, consideration may be given as to the degree to which the permittee should be required to meet the requirements of the water quality criteria in view of the nature and characteristics of the receiving stream. The spreadsheet has fourteen (14) data columns, all of which may not be applicable to any particular characteristic constituent of the discharge. A description of each column is as follows: Column 1: The "Stream Background" concentrations of the effluent characteristics. Column 2: The "Chronic" Fish and Aquatic Life Water Quality criteria. For Cadmium,

Copper, Lead, Nickel, and Zinc, this value represents the criteria for the dissolved form at laboratory conditions. The Criteria Continuous Concentration (CCC) is calculated using the equation: CCC = (exp m e

[ In (stream hardness) ] b c }) (CCF) CCF = Chronic Conversion Factor

Column 3: This equation and the appropriate coefficients for each metal are from

Tennessee Rule 1200-4-3-.03 and the EPA guidance contained in The Metals Translator: Guidance For Calculating A Total Recoverable Permit Limit From a Dissolved Criterion (EPA 823-B-96-007, June 1996). Values for other metals are in the total form and are not hardness dependent; no chronic criteria exists for silver. Published criteria are used for non-metal parameters. The "Acute" Fish and Aquatic Life Water Quality criteria. For Cadmium, Copper, Lead, Nickel, Silver, and Zinc, this value represents the criteria for the dissolved form at laboratory conditions. The Criteria Maximum Concentration (CMC) is calculated using the equation: CMC = (exp mA [ In (stream hardness) ] + bA }) (ACF)

ACF = Acute Conversion Factor This equation and the appropriate coefficients for each metal are from Tennessee Rule 1200-4-3-.03 and the EPA guidance contained in The Metals Translator: Guidance For Calculating A Total Recoverable Permit Limit From a Dissolved Criterion (EPA 823-B-96-007, June 1996). Values for other metals are in the total form and are not hardness dependent; no acute criteria exists for Total Chromium. Published criteria are used for non-metal parameters. Column 4: The "Fraction Dissolved" converts the value for dissolved metal at laboratory

conditions (columns 2 & 3) to total recoverable metal at in-stream ambient

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-36 of R-43 

## APPENDIX 5a (Continued) conditions (columns 5 & 6). This factor is calculated using the linear partition coefficients found in The Metals Translator: Guidance For Calculating A Total Recoverable Permit Limit From a Dissolved Criterion (EPA 823-B-96-007, June 1996) and the equation:

Cdiss 

### 1

Ctotal 

### 1 + [Kim] [ss 1+a)] [10-6] ss = in-stream suspended solids concentration [mg/I] Linear partition coefficients for streams are used for unregulated (7010) receiving waters, and linear partition coefficients for lakes are used for regulated (1010) receiving waters. For those parameters not in the dissolved form in columns 2 & 3 (and all non-metal parameters), a Translator of 1 is used. Column 5: The "Chronic" Fish and Aquatic Life Water Quality criteria at in-stream ambient

conditions. This criteria is calculated by dividing the value in column 2 by the value in column 4. Column 6: The "Acute" Fish and Aquatic Life Water Quality criteria at in-stream ambient

conditions. This criteria is calculated by dividing the value in column 3 by the value in column 4. Column 7:

Column 8:

Column 9: The "Chronic" Calculated Effluent Concentration for the protection of fish and

aquatic life. This is the chronic limit. The "Acute" Calculated Effluent Concentration for the protection of fish and aquatic life. This is the acute limit. The In-Stream Water Quality criteria for the protection of Human Health associated with the stream use classification of Organism Consumption (Recreation). Column 10: The In-Stream Water Quality criteria for the protection of Human Health

associated with the stream use classification of Water and Organism Consumption. These criteria are only to be applied when the stream use classification for the receiving stream includes both "Recreation" and "Domestic Water Supply." Column 11: The In-Stream Water Quality criteria for the protection of Human Health

associated with the stream use classification of Domestic Water Supply. Column 12: The Calculated Effluent Concentration associated with Organism Consumption. Column 13: The Calculated Effluent Concentration associated with Water and Organism

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

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-37 of R-43 

## APPENDIX 5a (Continued) The calculated chronic water quality effluent concentrations from Column 7 should be compared, individually, to the values calculated in Columns 12, 13, and 14 in order to determine the most stringent chronic permit limitations. The calculated acute water quality effluent concentrations from Column 8 should then be compared, individually, to values equal to two (2) times the values presented in Columns 12, 13, and 14 in order to determine the most stringent acute permit limitations. These water quality based limits should then be compared to any technology based (CFR or Tennessee "Rules") effluent limitations, and/or any previous permit limitations, for final determination of the permit limits.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-38 of R-43
APPENDIX 5b Determining Ash Pond Free Water Volume



### Tennessee Valley Authority - Bull Run Fossil Plant Ash Pond Required Free Volume Calculations Dry Weather Volume

Source [MGDI 

### Wet Weather Volume

Boiler Bay Bilge Sump 1.643 Ash ponds & metal waste treatment ponds 55 acres Hydroveyers (ash collection) 3.1900 Coal Yard Drainage Basin 140.5 acres MCW Treatment Pond 0.0052 Stack Yard Sump 11460 Total drainage area providing runoff 195.5 acres Ash Collection Tanks 9.5520 to the ash pond (includes ash pond) Coal Yard Drainage Basin Surrp 1.1660 Ash Sluice Line Low Point Sump 0.0565 10 year - 24 hour storm event 5.1 inches Main Station Sump 1.1240 Unw ater Sump 0.0142 Wet Weather Volume 27,072,300 gallons FGD Detention Sump 0.0270 Rim Ditch Discharge 0.7300 Dry Weather Volume 19,153,900 gallons Precipitation 0.5000 Total Required Volume 46,226,200 gallons

Total - Dry Weather Volume 19.1539

* Not used in calculations since metal cleaning wastes and ash transport water do not normally occur simultaneously.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-39 of R-43
APPENDIX 5c Water Quality Based Effluent Calculations

FACILITY: PERMIT #: TVA - Bull Run Fossil Plant

TN0005410

Stream (1Q10) Stream

(30Q5) Waste

Flow T1I. Susp.

Solids Hardness

(as CaCO3) Stream

Allocation IMOD] [MOD] [MOD] [mg/1] [mg/1] IN 129.300 424.600 19.037 10 145 90 1 2 3 4 5 [ 6 I 7 8 Stream Bckgrnd. Com. - Fish/Aqua. Lite

Water Quality Criteria Effluent Fraction Dissolved Fish & Aquatic Life Water Quality Criteria (1010)

In-Stream Allowable Calc. Effluent Concentration EFFLUENT CHARACTERISTIC Chronic Acute Chronic Acute Chronic Acute [ug/1] [ug/11 [ug/I] [Fraction] [ug/I] ILIgill lug/I] [ug/I] Arsenic 2.50 150 340 1.000 150.00 340.00 1036.6 2369.1 Cadmium * 2.50 1.357 5.537 0.193 7.04 28.72 34.1 186.2 Copper* 3.00 15.59 24.15 0.218 71.54 110.80 483.3 758.7 Lead * 1.60 3.76 96.55 0.143 26.22 672.87 174.1 4708.9 Silver * 2.50 NA 6.537 0.850 NA 7.69 NA 38.6 Nickel * 13.00 215.25 1938.20 0.206 1046.14 9419.74 7256.9 65979.6 Mercury, (T) *** 0.10 0.700 1.400 1.000 R 0.700 1.400 4.30 9.2 Chromium (T)**** 0.50 74.00 570.00 1.000 74.000 570.000 515.9 3994.3 Selenium ""*"" 0.50 5.00 20.00 1.000 5.000 20.000 32.0 137.2

The Fish & Aquatic Life and calculated effluent

In cases where the
than toxicity.

2C
30Q5 flow. 9 10 11 12 I 13 74

Human Health Wate Quality Criteria (3005) In-Stream Criteria Cale. Effluent Concentration EFFLUENT CHARACTERISTIC Organisms Voter/Organism DWS Organisms Vater/Organis m: DWS Iug/ 1 1 [ugll] [41] [ug/I] [ug/I] [ug/1]

159.6 Arsenic 10.0 10.0 10.0 46.3 159.6 Cadmium * NA NA 5.0 NA NA 54.7 Copper* NA WA NA NA NA NA Lead * NA NA 5.0 NA NA 72.8 Silver * NA NA 100.0 NA NA 2047.2 Nickel * 4600.0 610.0 100.0 96217.3 12532.9 1836.4 Mercury, (T) *** 0.051 0.05 2.0 -0.938 -0.959 39.9 Chromium (T)*"" NA NA 100.0 NA NA 2087.3 Selenium NA NA 5.0 NA NA 104.9

* Denotes metals for which Fish & Aquatic Life Criteria are expressed as a function of total hardness. criteria for this metal are in the dissolved form at laboratory conditions. The in-stream allowable criteria concentrations are in the total recoverable form.
11,1e Stream background concentrations are taken from Outfall 002 intake sample on the permit application. background concentration was reported as less than a value, one half of the value was used. The chronic criterion for mercury is not converted to dissolved, since it is based on fish tissue data rather """* The criteria for this parameter are in the total recoverable form. ***** Stream background concentration for selenium is half of the intake value of <0.001 mg/I reported on Form

and for arsenic is half of the intake value of <.005 mg/I. NOTE: Water Quality criteria for stream use classifications other than Fish & Aquatic Life are based on the

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-40 of R-43
APPENDIX 5d Comparison of Effluent Limits

COMPARISON DETERMINATION OF

TVA- Bull OF APPLICABLE MONITORING

Run Fossil Outfall 001

EFFLUENT REQUIREMENTS BY LIMITATIONS

Plant

RDL * ' DMR Summary** Application Sample Tennessee Rules Water

Quality*** Long Term Average Daily

Maximum Daily

Maximum EFFLUENT CHARACTERISTIC [mg/I] [mg/I] [mg/I] [INA] [mg/1] [mg/I] Cadmium (T) 0.001 0.0004 0.0005 0.0007 0.002 0.06 Chromium (T) 0.001 0.002 0.004 0.0015 0.57 2.09 Copper (T) 0.001 0.0044 0.0057 0.0050 0.013 0.758 Iron (T) -- 0.25 0.34 0.200 Lead (T) 0.001 0.0010 0.0020 0.0020 0.065 0.07 Manganese (T) -- 0.046 0.078 0.060 NA Mercury, (T) 0.0002 0.002 0.002 <0.0002 0.00005 -0.0009 Silver (T) 0.001 0.0004 0.0010 <0.0005 0.003 0.038 Nickel 0.01 0.0085 0.47 1.836 Arsenic 0.001 0.011 0.34 0.16 Selenium (T) 0.002 0.0120 0.0280 0.015 0.02 0.1050

* Required Detection Level per State of Tennessee Rule 1200-4-3-.05(8) ** Data reported 2005 - 09.
*** Most stringent applicable water quality based limit.TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-41 of R-43

APPENDIX 6 New Permit Limits

OUTFALL 001

EFFLUENT LIMITATIONS MONITORING MONTHLY DAILY REQUIREMENTS EFFLUENT AVG. CONC. AVG. AMNT. MAX CONC. MAX. AMNI MS RMNT. SAMPLE CHARACTERISTIC (mg/1) (lb/day) (mg.fl) (lb/day) FRQ NCY. TYPE

FLOW Report (MGD)* Report (MGD) * 1/Week Instantaneous pH — Range 6.0 - 9.0 1/VVeek Grab OIL & GREASE 12.0 -- 16.0 -- 1/Month Grab TOTAL SUSPENDED SOLIDS (TSS) 26.0 -- 84.0 -- 1/Month Grab NITROGEN, AMMONIA TOTAL (Plant

Intake) . -- Report Report 1/Month Grab NITROGEN, AMMONIA TOTAL -- -- Report Report 1/Month Grab NITROGEN, AMMONIA TOTAL (Net

Discharge) -- -- Report **** Report 1/Month Calculated ARSENIC, TOTAL -- -- Report -- 1/Month Grab CADMIUM, TOTAL -- -- Report -- 1/Month Grab COPPER,TOTAL -- -- Report -- 1/Month Grab LEAD, TOTAL -- -- Report -- 1/Month Grab MERCURY, TOTAL -- -- Report -- 1/Month Grab NICKEL, TOTAL — -- Report — 1/Month Grab SELENIUM, TOTAL -- -- Report -- 1/Month Grab THALLIUM, TOTAL -- -- Report -- 1/Month Grab ZINC, TOTAL -- -- Report -- 1/Month Grab IRON, TOTAL -- -- Report -- 1/Month Grab SILVER, TOTAL -- -- Report -- 1/Year Grab IC25 Survival, Reproduction, & Growth in 100% Effluent Annually Grab***
Note: The permittee shall take reasonable steps to prevent discharge of cenospheres other than in trace amounts from the outf

* Flow shall be reported in Million Gallons per Day (MGD). pH analyses shall be performed within fifteen (15) minutes of sample collection. *** See Part III for methodology. **** If a calculated value for net addition of ammonia as nitrogen exceeds an action concentration value of 1.0 mg/L, the permittee should investigate source(s) of ammonia, and proceed with a corrective action(s), if necessary. Furthermore, Knoxville EFO shall be notified within 24 hours from the time the permittee receives results indicating that an action value of 1.0 mg/L was exceeded

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-42 of R-43



## APPENDIX 6b New Permit Limits [CONTINUED)

PERMIT LIMITS

OUTFALL 002

EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. AM NT. MAX CONC. MAX AM NT. MSPNI NT. FRONCY. SAMPLE TYPE (n4 1 ) Ob/day) (mgII) (Ibiday) FLOW Report (MGD) Report (MGD) 1 / Day Estimate 1 TEMPERATURE, Intake Report -- Report -- 1 /Day Grab TEMPERATURE, Effluent -- 31.1°C (88°F) 1 /Day Calculated 2 TOTAL RESIDUAL OXIDANT (reported as chlorine) 3 0.011 -- 0.019 -- 1 / Week 4 Grab

In take temperature is measured hourly and reported discharge temperature shall be c alculated to r th ec — unit load, and th e 24-hour average llowthrough Outfall

Ie2b as the average of the hourly measurements poling c hannel based on the 24-hour average OP. I Survival, Reproduction, & fo r each day. The intake temperature urowth in 11)0% daily maximum

24-hour av erage 1 / Day Log Records

ettruent Once 6 Composite 6

1 Flow shall be estimated from pump logs and reported in Million Gallons per Day (MOD).
; Except for pea ods of rnacrol nvertebrate c ontrol when orddant addition Is required (see Permit - Part III), s ampless hall be taken once at the beginning of the period of chlorination for one unit and once every lb minutes thereafter. At the end of th e period of chlorination, a nesarnple shall be taken. Sampling for these oAdants is not required when there is no c h lori ne/bromine added during th al day.
, Application of a oxidant (brombek Hoene) beyond th e 120 minutes perday will be allowed to faciftatenuisance mac roinvertebrate contr ol ac co Wino to the Plan for such acliviti es described n Permit - Part III. The acceptable methods for analysis of TR are any mernous specmeu in Cu urm, ran I JO. I ne memou uetecuon ievei sur 1114-• snail net exceec u.uo mgr I unless the permittee demonstrates that its is higher. The permittee shall retain the documentation that justifies the higher MDL, and shall have that documentation available for review upon request. In cas where the permit limit is less than the MDL, the reporting of

- FRC at less than the MDL shall be interpreted to constitute compliance with the permit limit.

4

5

6 See Part Ill for methodology. Toxicity tests shall be performaecl only if biocides are added to the cooling water.

OUTFALL 004 Intake Screen Backwash Water

No numerical limitations or monitoring requirements. The discharge shall not have a visible oil sheen and the permitee shall take reasonable steps to prevent the return of materials collected on the screens to the receiving waters in a way that causes and unattractive condition on the recieving waters.

### TVA-Bull Run Fossil Plant (Rationale) NPDES Permit TN0005410 Page R-43 of R-43



## APPENDIX 6c New Permit Limits (Continued)

PERMIT LIMITS

INTERNAL MONITORING POINT 005

EFFLUENT LIMITATIONS MONITORING REQUIREMENTS MONTHLY DAILY EFFLUENT CHARACTERISTIC AVG. CONC. AVG. ANENT. E MAX. CONC. MAK AMNT. MS RNENT. FRQNC Y. SAMPLE
TYPE (Flgn) (lb/day) (mg/l) (lb/day) FLOW Report (MGD) * Report (MGD) * 1/Batch Estimate* IRON, TOTAL 1.0 -- 1.0 -- .. Grab COPPER,TOTAL 1.0 -- 1.0 -- ** Grab
Flow shall be reported in Million Gallons per Day (MGD), and shall be estimated based on elevation change. The permittee will be required to monitor discharges through IMP005 only when metal cleaning operations or other process wastewater generating activities occur.