PLAIN-TEXT TRANSCRIPT Document: Draft NPDES Permit for Plainfield Renewable Energy Issuer: Connecticut Department of Energy and Environmental Protection Original source: https://www.epa.gov/system/files/documents/2025-12/draftct0030473permit-2025.pdf Extraction method: layout-aware native PDF text extraction The PDF controls if layout, tables, symbols, columns, or page order differ from this text version. [Page 1] portal.ct.gov/DEEP National Pollutant Discharge Elimination System Permit issued to Permittee: Location Address: Plainfield Renewable Energy, LLC 12 Mill Brook Road 12 Mill Brook Road Plainfield, CT 06374 Plainfield, CT 06374 Permit ID: CT0030473 Effective Date: [1st of the month following signing] Receiving Waterbody: Quinebaug River Issuance Date: [date of signature] Receiving Waterbody ID: CT3700-00_02 Permit Expires: [5 yrs after effective date] SECTION 1: GENERAL PROVISIONS 1.1 This permit is reissued in accordance with Section 22a-430 of Chapter 446k, Connecticut General Statutes (“Conn. Gen. Stat.”), and Regulations of Connecticut State Agencies (“Regs. Conn. State Agencies”) adopted thereunder, as amended, and Section 402(b) of the Clean Water Act (“CWA”), as amended, 33 USC 1251, et. seq., and pursuant to an approval dated September 26, 1973, by the Administrator of the United States Environmental Protection Agency for the State of Connecticut to administer a National Pollutant Discharge Elimination System (“NPDES”) permit program. 1.2 Plainfield Renewable Energy, LLC (“Permittee”) shall comply with all conditions of this permit including the following sections of the Regs. Conn. State Agencies which have been adopted pursuant to Section 22a-430 of the Conn. Gen. Stat. and are hereby incorporated into this permit. Your attention is especially drawn to the notification requirements of subsections (i)(2), (i)(3), (j)(1), (j)(6), (j)(8), (j)(9)(C), (j)(10)(C), (j)(11)(C), (D), (E), and (F), (k)(3) and (4) and ( l)(2) of Section 22a-430-3. Section 22a-430-3: General Conditions (a) Definitions (b) General (c) Inspection and Entry (d) Effect of a Permit (e) Duty to Comply (f) Proper Operation and Maintenance (g) Sludge Disposal (h) Duty to Mitigate (i) Facility Modifications; Notification (j) Monitoring, Records and Reporting Requirements (k) Bypass (m) Effluent Limitation Violations (Upsets) (n) Enforcement (o) Resource Conservation (p) Spill Prevention and Control (q) Instrumentation, Alarms, Flow Recorders (r) Equalization PERMIT No. CT0030473 and SP0002464 Page 1 [Page 2] Section 22a-430-4: Procedures and Criteria (a) Duty to Apply (b) Duty to Reapply (c) Application Requirements (d) Preliminary Review (e) Tentative Determination (f) Draft Permits, Fact Sheets (g) Public Notice, Notice of Hearing (h) Public Comments (i) Final Determination (j) Public Hearings (k) Submission of Plans and Specifications, Approval (l) Establishing Effluent Limitations and Conditions (m) Case by Case Determinations (n) Permit Issuance or Renewal (o) Permit Transfer (p) Permit Revocation, Denial or Modification (q) Variances (s) Treatment Requirements 1.3 Violations of any of the terms, conditions, or limitations contained in this permit may subject the Permittee to enforcement action including, but not limited to, seeking penalties, injunctions and/or forfeitures pursuant to applicable sections of the Conn. Gen. Stat. and Regs. Conn. State Agencies. 1.4 Any false statement in any information submitted pursuant to this permit may be punishable as a criminal offense under Section 22a-438 or 22a-131a of the Conn. Gen. Stat. or in accordance with Section 22a-6, under Section 53a-157b of the Conn. Gen. Stat. 1.5 The authorization to discharge under this permit may not be transferred without prior written approval of the Commissioner of Energy and Environmental Protection (“Commissioner”). To request such approval, the Permittee and proposed transferee shall register such proposed transfer with the Commissioner, at least thirty (30) days prior to the transferee becoming legally responsible for creating or maintaining any discharge which is the subject of the permit transfer. Failure, by the transferee, to obtain the Commissioner's approval prior to commencing such discharge(s) may subject the transferee to enforcement action for discharging without a permit pursuant to applicable sections of the Conn. Gen. Stat. and Regs. Conn. State Agencies. 1.6 No provision of this permit and no action or inaction by the Commissioner shall be construed to constitute an assurance by the Commissioner that the actions taken by the Permittee pursuant to this permit will result in compliance or prevent or abate pollution. 1.7 Nothing in this permit shall relieve the Permittee of other obligations under applicable federal, state and local law. 1.8 An annual fee shall be paid for each year this permit is in effect as set forth in Section 22a-430-7 of the Regs. Conn. State Agencies. DRAFT PERMIT No. CT0030473 and SP0002464 Page 2 [Page 3] 1.9 The Permittee shall operate and maintain its collection and treatment system in accordance with its Operation and Maintenance Plan and with any approvals issued in accordance with Regs. Conn. State Agencies Section 22a-430-3(i)(3). The Permittee shall revise and maintain the Operation and Maintenance Plan upon the Commissioner’s request or to address equipment or operational changes in accordance with Regs. Conn. State Agencies Section 22a-430-3(f)(2). 1.10 The Permittee shall implement its Spill Prevention and Control Plan in accordance with Regs. Conn. State Agencies Section 22a-430-3(p) and 22a-430-4(c)(10). The plan shall include practices, procedures and facilities designed to prevent, minimize and control spills, leaks or such other unplanned releases of all toxic or hazardous substances and any other substances to prevent pollution of the waters of the state. Such requirements shall, unless otherwise allowed by the Commissioner, apply to all facilities used for storing, handling, transferring, loading or unloading such substances, including manufacturing areas. The Permittee shall revise and maintain the Spill Prevention and Control Plan upon the Commissioner’s request to address equipment or operational changes. SECTION 2: DEFINITIONS 2.1 The definitions of the terms used in this permit shall be the same as the definitions contained in Section 22a-423 of the Conn. Gen. Stat. and Section 22a-430-3(a) and 22a-430-6 of the Regs. Conn. State Agencies. 2.2 In addition to the above, the following definitions shall apply to this permit: “40 CFR” means Title 40 of the Code of Federal Regulations. “Annually” when used as a sampling frequency in Table A of this permit, means that sampling is required in the month of March, and in Table C, means that sampling is required in the month of July, August or September. “Average Monthly Limit” means the maximum allowable “Average Monthly Concentration” as defined in Section 22a-430-3(a) of the Regs. Conn. State Agencies when expressed as a concentration (e.g., mg/l). Otherwise, it means “Average Monthly Discharge Limitation” as defined in Section 22a-430-3(a) of the Regs. Conn. State Agencies . “Cooling water intake structure” means the total physical structure and any associated constructed waterways used to withdraw cooling water from waters of the state. The cooling water intake structure extends from the point at which water is withdrawn from the surface water source up to, and including, the intake pumps. Connecticut Water Quality Standards means the regulations adopted under Regs. Conn. State Agencies Sections 22a-426-1 through 22a-426-9, as amended. “Daily Concentration” means the concentration of a substance as measured in a daily composite sample, or the arithmetic average of all grab sample results defining a grab sample average. “Daily Quantity” means the quantity of waste discharged during an operating day. “Dilution Factor” means the inverse of the “Instream Waste Concentration”. “DMR” means Discharge Monitoring Report. DRAFT PERMIT No. CT0030473 and SP0002464 Page 3 [Page 4] “IC” means “Inhibition Concentration”. “IC25” means a point estimate of the toxicant concentration that would cause a twenty-five (25) percent reduction in a non-lethal biological measurement of the test organism, such as reproduction or growth. “Instantaneous Limit” means the highest allowable concentration of a substance as measured by a grab sample, or the highest allowable measurement of a parameter as obtained through instantaneous monitoring. “In-stream Waste Concentration” (“IWC%”) means the concentration (as a percent) of the effluent in the receiving water. “LC” means Lethal Concentration “LC50” means the concentration lethal to fifty (50) percent of the test organisms during a specific period. “Lowest Observed Effect Concentration” (“LOEC”) means the lowest concentration of an effluent or toxicant to which organisms are exposed in a life cycle or partial life-cycle test, which causes adverse effects on the test organisms. “Maximum Daily Limit” means the maximum allowable “Daily Concentration” (defined above) when expressed as a concentration (e.g., mg/l). Otherwise, it means the maximum allowable “Daily Quantity” as defined above, unless it is expressed as a flow quantity. If expressed as a flow quantity, it means “Maximum Daily Flow” as defined in Section 22a- 430-3(a) of the Regs. Conn. State Agencies. “No Observed Effect Concentration” (“NOEC”) means the highest concentration of an effluent or toxicant to which organisms are exposed in a life cycle or partial life-cycle test, that causes no observable adverse effects on the test organisms. “Quarter” means the calendar quarter beginning at 12:00 AM on the first day of March, June, September, and December and ending at 12:00 AM on the first day of June, September, December, and March, respectively. “Quarterly”, when used as a sampling frequency in this permit, means that sampling is required in the months of March, June, September, and December. “Range During Sampling” (“RDS”), as a sample type, means the maximum and minimum of all values recorded as a result of analyzing each grab sample of: 1) a Composite Sample or, 2) a Grab Sample Average. For those permittees with continuous monitoring and recording pH meters, Range During Sampling means the maximum and minimum readings recorded with the continuous monitoring device during the Composite or Grab Sample Average sample collection. “Reporting Frequency” means the frequency at which monitoring results must be provided. DRAFT PERMIT No. CT0030473 and SP0002464 Page 4 [Page 5] SECTION 3: COMMISSIONER'S DECISION 3.1 The Commissioner has issued a final determination and found that 1) with respect to the discharge, DSN 101-1, continuance of the existing system to treat the discharge would protect the waters of the state from pollution; and 2) with respect to discharges, DSN 102-1, DSN 103-1 and DSN 104-1, continuance of the existing discharges would not cause pollution of the waters of the state. The Commissioner’s decision is based on Application No. 201801971 for permit reissuance received on February 28, 2018, and the administrative record established in the processing of that application. 3.2 Upon the effective date of this permit and continuing until this permit expires or is modified or revoked, the Commissioner hereby authorizes the Permittee to discharge in accordance with the terms and conditions of this permit, the information provided in Application No. 201801971, received by the Commissioner on February 28, 2018, the administrative record established in the processing of that application, and all modifications and approvals issued by the Commissioner or the Commissioner’s authorized agent, for the discharge and/or activities authorized by, or associated with this Permit. 3.3 The Commissioner reserves the right to make appropriate revisions to the permit in order to establish any appropriate effluent limitations, schedules of compliance, or other provisions which may be authorized under the Federal Clean Water Act or the Conn. Gen. Stat. or regulations adopted thereunder, as amended. The permit as modified or renewed under this paragraph may also contain any other requirements of the Federal Clean Water Act or the Conn. Gen. Stat. or regulations adopted thereunder which are then applicable. 3.4 This permit includes an interim determination regarding Section 316(a) of the Federal Water Pollution Control Act 33 U.S.C. § 1326(a) regarding the thermal component of the discharge, and compliance with this permit is sufficient to assure the protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife in and on the receiving waters. 3.5 This permit also contains a determination under Section 316(b) of the Federal Water Pollution Control Act, 33 U.S.C. § 1326(b) regarding cooling water intake structures and Conn. Gen. Stat. § 22a-430(a), and compliance with this permit is sufficient to assure the protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife in and on the receiving waters. Based on the evaluation detailed in the fact sheet, DEEP has determined that the facility employs BTA pursuant to 40 CFR § 125.90(b). 3.6 Nothing in this permit authorizes take for the purposes of a facility's compliance with the Endangered Species Act. SECTION 4: GENERAL EFFLUENT LIMITATIONS 4.1 The Permittee shall assure that the surface water affected by the subject discharge shall conform to the Connecticut Water Quality Standards (“WQS”). 4.2 No discharge shall contain, or cause in the receiving stream, a visible oil sheen or floating solids, or cause visible discoloration or foaming in the receiving stream. 4.3 No discharge shall cause acute or chronic toxicity in the receiving water body beyond any zone of influence specifically allocated to that discharge in this permit. 4.4 The temperature of any discharge shall not increase the temperature of the receiving stream above 85 °F, or in any case, raise the temperature of the receiving stream by more than 4 °F. DRAFT PERMIT No. CT0030473 and SP0002464 Page 5 [Page 6] 4.5 The Permittee is prohibited from discharging polychlorinated biphenyl compounds such as those commonly used for transformer fluid. 4.6 The Permittee is prohibited from using any chemical(s) that contain phosphorus in any process or activity that may result in a discharge to the waters of the state. SECTION 5: SPECIFIC EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS 5.1 The discharge is restricted by and shall be monitored in accordance with the following tables in this section. The wastewater discharge shall not exceed the effluent limitations in these tables and shall otherwise conform to the specific terms and conditions listed in the tables. The Permittee shall comply with the “Remarks” and “Footnotes” noted in the tables that follow. Such remarks and footnotes are enforceable like any other term or condition of this permit. 5.2 The wastewaters authorized/approved by this permit shall be collected, treated, and discharged in accordance with this permit and with any approvals issued by the Commissioner or his/her authorized agent for the discharges and activities authorized by or associated with this permit. Any wastewater discharges not expressly identified in these tables or otherwise approved to be discharged by this permit shall not be authorized by this permit. 5.3 All samples shall be comprised of only the wastewater described in these tables. Samples shall be collected prior to combination with receiving waters or wastewater of any other type, and after all approved treatment units, if applicable. Samples and measurements taken for the purpose of monitoring shall be representative of the monitored activity. Collection of permit-required effluent samples in any location other than the authorized location noted in this permit shall be a violation of this permit. 5.4 In cases where limits and sample type are specified but sampling is not required by this permit, the limits specified shall apply to all samples which may be collected and analyzed by the Department of Energy and Environmental Protection (“DEEP”) personnel, the Permittee, or other parties. 5.5 The Permittee shall operate and maintain the outdoor wood storage area in accordance with “Section A.4 Stormwater Management – Outdoor Wood Storage Area” of the response to comment report dated February 19, 2008. DRAFT PERMIT No. CT0030473 and SP0002464 Page 6 [Page 7] TABLE A Discharge Serial Number: DSN 101-1 Monitoring Location: 1 (External outfall) Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated Zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING MINI- NET Instantaneous Sample Type or MUM PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Limit or Sample/ Measurement to LEVEL 2 CODE Monthly Daily Reporting Measurement to be Required Reporting be Reported (µg/l) Limit Limit Frequency 1 Reported Range Frequency 1 Aluminum, Total 01105 mg/L 1.42 2.86 Weekly Daily Composite 4.29 NR Grab 10.0 Aluminum, Total 01105 kg/d 0.68 1.36 Weekly Daily Composite NA NR Grab 10.0 Ammonia (as N) 00610 mg/L --- --- Weekly Daily Composite --- NR NA Ammonia (as N) 00610 kg/d --- --- Weekly Daily Composite NA NR NA Boron 01022 mg/l --- --- Weekly Daily Composite NA NR NA Chlorine, Total Residual 50060 mg/L 0.14 0.33 Weekly Grab Sample Average 0.497 NR Grab 20.0 Chromium, Total 01034 mg/L --- --- Weekly Daily Composite NA NR NR 5.0 Copper, Total 01042 mg/L 0.096 0.190 Weekly Daily Composite 0.288 NR Grab 3.0 Copper, Total 01042 kg/d 0.046 0.091 Weekly Daily Composite NA NR NA 3.0 Flow Rate (Average Daily)3 00056 gpd 126,103 NA Weekly Total Daily Flow NA NR NA Flow, Maximum during 24-hr period3 50047 gpd NA 173,571 Weekly Total Daily Flow NA NR NA Iron, Total 01045 mg/L --- --- Weekly Daily Composite --- NR NA 100.0 Kjeldahl Nitrogen, Total (as N) 00625 mg/L --- --- Weekly Daily Composite NA NR NR Lead, Total 01051 mg/L 0.019 0.039 Weekly Daily Composite 0.058 NR Grab 1.0 Lead, Total 01051 kg/d 0.009 0.019 Weekly Daily Composite NA NR NR 1.0 Nitrate (as N) 00620 mg/L --- --- Weekly Daily Composite NA NR NR Nitrite (as N) 00615 mg/L --- --- Weekly Daily Composite NA NR NR Nitrogen, Total [See Remark e] 00600 lbs/day --- --- Weekly Calculated NA NR NR pH, Minimum 61942 S.U. NA NA NR NA 6.0 Continuous Continuous (Ends 12 months after permit’s effective date) pH, Maximum 61941 S.U. NA NA NR NA 9.0 Continuous Continuous (Ends 12 months after permit’s effective date) Phosphorus, Total 00665 mg/l --- --- Monthly Daily Composite NA NR NR 100.0 Temperature, Maximum 00011 oF NA NA NR NA 90 Hourly Instantaneous Temperature, intake/outlet differential 61576 oF NA NA NR NA --- Hourly Instantaneous Total Suspended Solids 00530 mg/L 20 30 Weekly Daily Composite 45 NR Grab Zinc, Total 01092 mg/L 0.64 1.30 Weekly Daily Composite 1.95 NR Grab 10.0 DRAFT PERMIT No. CT0030473 and SP0002464 Page 7 [Page 8] TABLE A Discharge Serial Number: DSN 101-1 Monitoring Location: 1 (External outfall) Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated Zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING MINI- NET Instantaneous Sample Type or MUM PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Limit or Sample/ Measurement to LEVEL 2 CODE Monthly Daily Reporting Measurement to be Required Reporting be Reported (µg/l) Limit Limit Frequency 1 Reported Range Frequency 1 126 Priority Pollutants (resulting 51168 mg/L NA NA NR NA --- Once during Grab from chemical additives for cooling permit term4 tower maintenance) except chromium and zinc APPLICABLE 12 MONTHS AFTER THE EFFECTIVE DATE OF PERMIT pH, Minimum 61942 S.U. NA NA NR NA 6.5 Continuous Continuous pH, Maximum 61941 S.U. NA NA NR NA 8.0 Continuous Continuous TABLE A FOOTNOTES AND REMARKS Footnotes: 1 The first entry in this column is the ‘Sample Frequency’. If a 'Reporting Frequency' does not follow this entry and the ‘Sample Frequency’ is more frequent than monthly, then the ‘Reporting Frequency’ is monthly. If the ‘Sample frequency’ is specified as monthly, or less frequent, then the ‘Reporting Frequency’ is the same as the ‘Sample Frequency’. 2 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Per mittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 3 For this parameter, the Permittee shall maintain at the facility a record of the total flow for each day of discharge and shall report the Average Daily Flow and the Maximum Daily Flow for each sampling month. 4 This monitoring shall be conducted once during the permit term by December 31, 2027, and submitted as an attachment to the December 2027 DMR. 126 Priority Pollutants shall be reported as the sum of the concentrations of any analytes detected above the minimum level. The full lab report, including minimum levels of the analytes determined to be non-detect, and the concentration of the detected analytes, shall be attached to the DMR. Remarks: a. Abbreviations used for units are as follows: gpd means gallons per day; kg/day means kilograms per day; mg/L means milligrams per liter; µg/L means micrograms per liter; SU means Standard Units; oF means degrees Fahrenheit; % means percentage. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit); RDS means Range During Sampling. b. If “---” is noted in the limit’s column in the table, this means that a limit is not specified but a value must be reported on the DMR. c. pH shall be reported to 0.1 SU. All other values shall be reported to the level of precision/accuracy reported by the laboratory. d. “Continuous”, used in this table as a “Sample” or “Sample Type”, means monitoring that produces one or more data points in fifteen minutes or less. e. Total Nitrogen means the sum of the concentrations of: Total Kjeldahl Nitrogen (Ammonia Nitrogen + Organic Nitrogen) + Nitrate Nitrogen + Nitrite Nitrogen. DRAFT PERMIT No. CT0030473 and SP0002464 Page 8 [Page 9] TABLE B – Acute Toxicity Monitoring Discharge Serial Number: DSN 101-AT Monitoring Locations: T – Acute toxicity effluent results and chemical analyses Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type or MUM CODE Limit or LEVEL 5 Monthly Maximum Reporting Measurement to be Limit or Reporting Measurement to (µg/l) Limit Daily Frequency 2, 3 Reported 4 Required Range Frequency be Reported Limit1 Whole Effluent Toxicity (WET) Acute Aquatic Toxicity6 TDA3D % NA ≥ 90 % Quarterly Daily Composite ≥ 90 % NR Grab Daphnia pulex, NOAEL = 100% Acute Aquatic Toxicity6 Pimephales promelas, NOAEL = TDA6C % NA ≥ 90 % Quarterly Daily Composite ≥ 90 % NR Grab 100% Chemical Analyses Required with Acute Whole Effluent Toxicity Monitoring – See Section 7.1.6. for Acute Testing 7 Date of Acute WET Chemistry 51883 YYYYMMDD NA --- Quarterly Calculated NA NR NA Sample Collection8 Alkalinity 00410 mg/L NA --- Quarterly Daily Composite NA NR NA Aluminum, Dissolved 01106 mg/L NA --- Quarterly Daily Composite NA NR NA 10.0 Aluminum, Total 01105 mg/L NA --- Quarterly Daily Composite NA NR NA 10.0 Boron, Total 01022 mg/l NA --- Quarterly Daily Composite NA NR NA Chlorine, Total Residual 50060 mg/L NA --- Quarterly Daily Composite NA NR NA 20.0 Chromium, Total 01034 mg/L NA --- Quarterly Daily Composite NA NR NA 5.0 Copper, Dissolved 01040 mg/L NA --- Quarterly Daily Composite NA NR NA 3.0 Copper, Total 01042 mg/L NA --- Quarterly Daily Composite NA NR NA 3.0 Dissolved Oxygen 00300 mg/L NA --- Quarterly Daily Composite NA NR NA Hardness, Total 00900 mg/L NA --- Quarterly Daily Composite NA NR NA Iron, Total 01045 mg/L NA --- Quarterly Daily Composite NA NR NA 100.0 Lead, Dissolved 01049 mg/L NA --- Quarterly Daily Composite NA NR NA 1.0 Lead, Total 01051 mg/L NA --- Quarterly Daily Composite NA NR NA 1.0 Nitrogen, Ammonia (total as N) 00610 mg/L NA --- Quarterly Daily Composite NA NR NA Nitrogen, Kjeldahl (total as N) 00625 mg/L NA --- Quarterly Daily Composite NA NR NA Nitrogen, Nitrate (total as N) 00620 mg/L NA --- Quarterly Daily Composite NA NR NA Nitrogen, Nitrite (total as N) 00615 mg/L NA --- Quarterly Daily Composite NA NR NA Nitrogen, Total (as N)9 00600 mg/L NA --- Quarterly Calculation NA NR NA DRAFT PERMIT No. CT0030473 and SP0002464 Page 9 [Page 10] TABLE B – Acute Toxicity Monitoring Discharge Serial Number: DSN 101-AT Monitoring Locations: T – Acute toxicity effluent results and chemical analyses Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- Daily MUM PARAMETER DMR UNITS Average Limit or Sample/ Sample Type or Instantaneous Sample/ Sample Type or LEVEL 5 CODE Monthly Maximum Reporting Measurement to be Limit or Reporting Measurement to (µg/l) Limit Frequency 2, 3 Reported 4 Required Range Frequency be Reported Daily Limit1 pH 00400 SU NA --- Quarterly Daily Composite NA NR NA Phosphorus, Total 00665 mg/L NA --- Quarterly Daily Composite NA NR NA 100.0 Specific Conductance 51409 uMhos NA --- Quarterly Daily Composite NA NR NA Temperature 00011 Deg. F. NA --- Quarterly Daily Composite NA NR NA Total Suspended Solids 00530 mg/L NA 30 Quarterly Daily Composite NA NR NA Zinc, Dissolved 01090 mg/L NA --- Quarterly Daily Composite NA NR NA 10.0 Zinc, Total 01092 mg/L NA 1.30 Quarterly Daily Composite NA NR NA 10.0 TABLE B FOOTNOTES AND REMARKS Footnotes: 1 WET limits are expressed as a minimum daily limit, meaning the minimum allowable daily discharge over the course of the 24-hour sampling period. Chemical results analyzed in conjunction with WET tests shall be reported as the max value collected during the 24-hour sampling period. 2 The first entry in this column is the “Sample Frequency”. If a “Reporting Frequency” does not follow this entry and the “Sample Frequency” is more frequent than monthly, then the “Reporting Frequency” is monthly. If the “Sample Frequency” is specified as monthly, or less frequent, then the “Reporting Frequency” is the same as the “Sample Frequency”. 3 If more than one toxicity sample is collected during a single month, report subsequent WET and chemistry results as an attachment to the DMR in accordance with Section 8.2 of this permit. 4 Daily composite samples shall be collected for acute toxicity tests consistent with the methodology outlined in Section 7.1 of this permit. 5 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Permittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 6 Acute toxicity testing shall be conducted in accordance with Section 7.1 of this permit. The NOAEL results (in % survival) for the acute toxicity testing shall be reported on the DMR. The Aquatic Toxicity Monitoring Report (“ATMR”) shall be completed for each toxicity testing event and submitted in accordance with Section 8.2 of this permit. 7 Chemical analyses shall be conducted on samples used in the acute toxicity tests. These analyses shall be conducted on all samples used in the acute toxicity test and reported under Monitoring Location T. Results shall also be included on the ATMR and submitted in accordance with Section 8.2 of this permit. 8 The Permittee shall report the date of sample collection for the acute toxicity test and associated chemistry data in the format: year month day (YYYYMMDD). 9 Total Nitrogen means the sum of the concentrations of: Total Kjeldahl Nitrogen + Nitrate Nitrogen + Nitrite Nitrogen. Remarks: 1. Abbreviations used for units are as follows: kg/day means kilograms per day; mg/L means milligrams per liter; mgd means millions of gallons per day; SU means Standard Units; mg/L means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit); RDS means Range During Sampling; RDM means Range During Month. 2. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. 3. Analyses that indicate that a parameter was not detected or that was detected less than the noted ML shall be reported in accordance with Section 6.6. DRAFT PERMIT No. CT0030473 and SP0002464 Page 10 [Page 11] TABLE C – Chronic Toxicity Monitoring Discharge Serial Number: DSN 101-CT Monitoring Locations: Y – Chronic toxicity effluent results O – Day 1 chronic toxicity chemical analyses P – Day 3 chronic toxicity chemical analyses Q – Day 5 chronic toxicity chemical analyses R – Day 1 upstream monitoring S – Day 3 upstream monitoring T – Day 5 upstream monitoring Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- MONI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type MUM 5 TORING CODE Monthly Limit or Reporting Measurement to Limit or Reporting or LEVEL LOCA- Limit Maximum Frequency be Reported 4 Required Frequency Measurement (µg/l) TION Daily 2, 3 Range to be Reported Limit1 Whole Effluent Toxicity (WET) Chronic Aquatic Toxicity (Survival)6 TOP3B % NA --- Annually Daily Composite NA NR NA Y Ceriodaphnia dubia, C-NOEC Chronic Aquatic Toxicity (Reproduction)6 TPP3B % NA --- Annually Daily Composite NA NR NA Y Ceriodaphnia dubia, C-NOEC Chronic Aquatic Toxicity (Survival)6 TOP6C % NA --- Annually Daily Composite NA NR NA Y Pimephales promelas, C-NOEC Chronic Aquatic Toxicity (Growth)6 TPP6C % NA --- Annually Daily Composite NA NR NA Y Pimephales promelas, C-NOEC Chemical Analyses Required with Chronic Whole Effluent Toxicity Monitoring – See Section 7.2.7. for Chronic Testing 7 Date of Chronic WET Chemistry 51883 YYYYMMDD NA --- Annually Calculated NA NR NA O, P, Q; Sample Collection8 R, S, T Alkalinity 00410 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Aluminum, Dissolved 01106 mg/L NA --- Annually Daily Composite NA NR NA 10.0 O, P, Q; R, S, T DRAFT PERMIT No. CT0030473 and SP0002464 Page 11 [Page 12] TABLE C – Chronic Toxicity Monitoring Discharge Serial Number: DSN 101-CT Monitoring Locations: Y – Chronic toxicity effluent results O – Day 1 chronic toxicity chemical analyses P – Day 3 chronic toxicity chemical analyses Q – Day 5 chronic toxicity chemical analyses R – Day 1 upstream monitoring S – Day 3 upstream monitoring T – Day 5 upstream monitoring Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- MONI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type MUM 5 TORING CODE Monthly Limit or Reporting Measurement to Limit or Reporting or LEVEL LOCA- Limit Maximum Frequency be Reported 4 Required Frequency Measurement (µg/l) TION Daily 2, 3 Range to be Reported Limit1 Aluminum, Total 01105 mg/L NA --- Annually Daily Composite NA NR NA 10.0 O, P, Q; R, S, T Boron, Total 01022 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Chlorine, Total Residual 50060 mg/L NA --- Annually Daily Composite NA NR NA 20.0 O, P, Q; R, S, T Copper, Dissolved 01040 mg/L NA --- Annually Daily Composite NA NR NA 3.0 O, P, Q; R, S, T Copper, Total 01042 mg/L NA --- Annually Daily Composite NA NR NA 3.0 O, P, Q; R, S, T Chromium, Total 01034 mg/L NA --- Annually Daily Composite NA NR NA 5.0 O, P, Q; R, S, T Dissolved Oxygen 00300 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Hardness, Total 00900 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Iron, Total 01045 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Lead, Dissolved 01049 mg/L NA --- Annually Daily Composite NA NR NA 1.0 O, P, Q; R, S, T Lead, Total 01051 mg/L NA --- Annually Daily Composite NA NR NA 1.0 O, P, Q; R, S, T DRAFT PERMIT No. CT0030473 and SP0002464 Page 12 [Page 13] TABLE C – Chronic Toxicity Monitoring Discharge Serial Number: DSN 101-CT Monitoring Locations: Y – Chronic toxicity effluent results O – Day 1 chronic toxicity chemical analyses P – Day 3 chronic toxicity chemical analyses Q – Day 5 chronic toxicity chemical analyses R – Day 1 upstream monitoring S – Day 3 upstream monitoring T – Day 5 upstream monitoring Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- MONI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type MUM 5 TORING CODE Monthly Limit or Reporting Measurement to Limit or Reporting or LEVEL LOCA- Limit Maximum Frequency be Reported 4 Required Frequency Measurement (µg/l) TION Daily 2, 3 Range to be Reported Limit1 Nitrogen, Ammonia (total as N) 00610 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Nitrogen, Kjeldahl (total as N) 00625 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Nitrogen, Nitrate (total as N) 00620 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Nitrogen, Nitrite (total as N) 00615 mg/L NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Nitrogen, Total (as N)9 00600 mg/L NA --- Annually Calculation NA NR NA O, P, Q; R, S, T pH 00400 SU NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Phosphorus, Total 00665 mg/L NA --- Annually Daily Composite NA NR NA 100.0 O, P, Q; R, S, T Specific Conductance 51409 uMhos NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Temperature 00011 Deg. F. NA --- Annually Daily Composite NA NR NA O, P, Q; R, S, T Total Suspended Solids 00530 mg/L NA 30 Annually Daily Composite NA NR NA O, P, Q; R, S, T Zinc, Dissolved 01090 mg/L NA --- Annually Daily Composite NA NR NA 10.0 O, P, Q; R, S, T DRAFT PERMIT No. CT0030473 and SP0002464 Page 13 [Page 14] TABLE C – Chronic Toxicity Monitoring Discharge Serial Number: DSN 101-CT Monitoring Locations: Y – Chronic toxicity effluent results O – Day 1 chronic toxicity chemical analyses P – Day 3 chronic toxicity chemical analyses Q – Day 5 chronic toxicity chemical analyses R – Day 1 upstream monitoring S – Day 3 upstream monitoring T – Day 5 upstream monitoring Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- MONI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type MUM 5 TORING CODE Monthly Limit or Reporting Measurement to Limit or Reporting or LEVEL LOCA- Limit Maximum Frequency be Reported 4 Required Frequency Measurement (µg/l) TION Daily 2, 3 Range to be Reported Limit1 Zinc, Total 01092 mg/L NA 1.3 Annually Daily Composite NA NR NA 10.0 O, P, Q; R, S, T DRAFT PERMIT No. CT0030473 and SP0002464 Page 14 [Page 15] TABLE C – Chronic Toxicity Monitoring Discharge Serial Number: DSN 101-CT Monitoring Locations: Y – Chronic toxicity effluent results O – Day 1 chronic toxicity chemical analyses P – Day 3 chronic toxicity chemical analyses Q – Day 5 chronic toxicity chemical analyses R – Day 1 upstream monitoring S – Day 3 upstream monitoring T – Day 5 upstream monitoring Wastewater Description: Treated cooling tower blowdown wastewater Outfall Location: Latitude (41° 39’ 35”) and Longitude (71° 57’ 49”) Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility Discharge is to: Quinebaug River Allocated zone of Influence: 137,750 gallons per hour Instream Waste Concentration for acute criteria: 5.4% Instream Waste Concentration for chronic criteria: 3.67% Monitoring Location Description: At the powerhouse prior to the discharge line exiting the facility FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET Minimum MINI- MONI- PARAMETER DMR UNITS Average Daily Sample/ Sample Type or Instantaneous Sample/ Sample Type MUM 5 TORING CODE Monthly Limit or Reporting Measurement to Limit or Reporting or LEVEL LOCA- Limit Maximum Frequency be Reported 4 Required Frequency Measurement (µg/l) TION Daily 2, 3 Range to be Reported Limit1 TABLE C FOOTNOTES AND REMARKS Footnotes: 1 WET limits are expressed as a minimum daily limit, meaning the minimum allowable daily discharge over the course of the 24-hour sampling period. Chemical results analyzed in conjunction with WET tests shall be reported as the max value collected during the 24-hour sampling period. 2 The first entry in this column is the “Sample Frequency”. If a “Reporting Frequency” does not follow this entry and the “Sample Frequency” is more frequent than monthly, then the “Reporting Frequency” is monthly. If the “Sample Frequency” is specified as monthly, or less frequent, then the “Reporting Frequency” is monthly. 3 If more than one toxicity sample is collected during a single month, report subsequent WET and chemistry results as an attachment to the DMR in accordance with Section 8.2 of this permit. 4 Daily composite samples shall be collected for chronic toxicity tests consistent with the methodology outlined in Section 7.2 of this permit. 5 “Minimum Level” refers to Section 6.4 of this permit. 6 Chronic toxicity testing shall be conducted in accordance with Section 7.2 of this permit. The C-NOEC (Chronic-No Observed Effect Concentration) results (in %) for the conditions noted in this table shall be reported on the DMR. The ATMR shall be completed for each chronic toxicity testing event and submitted in accordance with Section 8.2 of this permit. 7 Chemical analyses shall be conducted on all samples used in the chronic toxicity tests. These analyses shall be conducted on an undiluted aliquot of each effluent sample and each sample of upstream receiving water used in the chronic toxicity test. Results for effluent sampling from day 1, day 3, and day 5 of the chronic toxicity test shall be reported under Monitoring Location O, P, and Q, respectively. Receiving water (upstream) results from day 1, day 3, and day 5 of sampling shall be reported under reported under Monitoring Location R, S, and T, respectively. Results for salinity adjusted effluent sampling from day 1, day 3, and day 5 of the chronic toxicity test shall be reported under Monitoring Location U, V, and W, respectively. Results shall also be included on the ATMR and submitted in accordance with Section 8.2 of this permit. 8 The Permittee shall report the dates of sample collection for each day of chronic toxicity test chemistry sampling (days 1, 3, and 5) in the format: year month day (YYYYMMDD). 9 Total Nitrogen means the sum of the concentrations of: Total Kjeldahl Nitrogen + Nitrate Nitrogen + Nitrite Nitrogen. Remarks: 1. Sampling shall be in July, August or September. 2. Abbreviations used for units are as follows: kg/day means kilograms per day; mg/L means milligrams per liter; mgd means millions of gallons per day; SU means Standard Units; mg/L means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit); RDS means Range During Sampling; RDM means Range During Month. 3. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. 4. Analyses that indicate that a parameter was not detected or that was detected less than the noted ML shall be reported in accordance with Section 6.6. DRAFT PERMIT No. CT0030473 and SP0002464 Page 15 [Page 16] TABLE D Discharge Serial Number: DSN 102-1 Monitoring Location: 1 (External outfall) Wastewater Description: Fire pump test wastewater Outfall Location: Latitude (41° 39’ 42”) and Longitude (71° 55’ 28”) Monitoring Location Description: Prior to discharging into the in-ground stormwater infiltration system located at the south end the site Maximum Frequency of Discharge: Once per year Discharge is to: Infiltration into the groundwater of the Mill Brook watershed NET FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Instantaneous Sample/ Sample Type or MINIMUM 2 CODE Monthly Daily Reporting Measurement to Limit or Reporting Measurement to LEVEL 1 (µg/l) Limit Limit Frequency be Reported Required Range Frequency be Reported Aluminum, Total 01105 mg/L NA NA NR NA --- Annually Grab 10.0 Boron 01022 mg/L NA NA NR NA --- Annually Grab Copper, Total 01042 mg/L NA NA NR NA --- Annual Grab 3.0 Flow, Maximum during 24-hr period 50047 gpd NA 225,000 Annually Total Daily Flow NA NR NA Iron, Total 01045 mg/L NA NA NR NA --- Annually Grab Lead, Total 01051 mg/L NA NA NR NA --- Annually Grab 1.0 pH 00400 S.U. NA NA NR NA 6.0 – 9.0 Annually Grab Phosphorus, Total 00665 mg/L NA NA NR NA --- Annually Grab 100.0 Zinc, Total 01092 mg/L NA NA NR NA --- Annually Grab 10.0 TABLE D FOOTNOTES AND REMARKS Footnotes: 1 The first entry in this column is the ‘Sample Frequency’. If a 'Reporting Frequency' does not follow this entry and the ‘Sample Frequency’ is more frequent than monthly, then the ‘Reporting Frequency’ is monthly. If the ‘Sample frequency’ is specified as monthly, or less frequent, then the ‘Reporting Frequency’ is the same as the ‘Sample Frequency’. 2 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Permittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 3 For this parameter, the Permittee shall maintain at the facility a record of the Total Daily Flow and pH range for each operating day. The Permittee shall report on its DMR the “Average Daily Flow” and the “Maximum Daily Flow” and pH for each month and shall provide the record of the Total Daily Flow and pH range as an attachment to the DMR (Attachment D). Remarks: 1. Abbreviations used for units are as follows: gpd means gallons per day; mg/L means milligrams per liter; SU means Standard Units; µg/l means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit). 2. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. DRAFT PERMIT No. CT0030473 and SP0002464 Page 16 [Page 17] TABLE E Discharge Serial Number: DSN 103-1 Monitoring Location: 1 (External outfall) Wastewater Description: Fire hydrant test wastewater Outfall Location: Latitude (41° 39’ 42”) and Longitude (71° 55’ 28”) Monitoring Location Description: Prior to discharging into the in-ground stormwater infiltration system located at the south and north ends of the site (See the remark below) Maximum Frequency of Discharge: Once per year Discharge is to: Infiltration into the groundwater of the Mill Brook watershed NET FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Instantaneous Sample/ Sample Type or MINIMUM CODE LEVEL2 Monthly Daily Reporting Measurement to Limit or Reporting Measurement to (µg/l) Limit Limit Frequency 1 be Reported Required Range Frequency be Reported Aluminum, Total 01105 mg/L NA NA NR NA --- Annually Grab 10.0 Boron 01022 mg/L NA NA NR NA --- Annually Grab Copper, Total 01042 mg/L NA NA NR NA --- Annual Grab 3.0 Flow, Maximum during 24-hr period 50047 gpd NA 225,000 Annually Total Daily Flow NA NR NA Iron, Total 01045 mg/L NA NA NR NA --- Annually Grab 100.0 Lead, Total 01051 mg/L NA NA NR NA --- Annually Grab 1.0 pH 00400 S.U. NA NA NR NA 6.0 – 9.0 Annually Grab Phosphorus, Total 00665 mg/L NA NA NR NA --- Annually Grab 100.0 Zinc, Total 01092 mg/L NA NA NR NA --- Annually Grab 10.0 TABLE E FOOTNOTES AND REMARKS Footnotes: 1 The first entry in this column is the ‘Sample Frequency’. If a 'Reporting Frequency' does not follow this entry and the ‘Sample Frequency’ is more frequent than monthly, then the ‘Reporting Frequency’ is monthly. If the ‘Sample frequency’ is specified as monthly, or less frequent, then the ‘Reporting Frequency’ is the same as the ‘Sample Frequency’. 2 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Permittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 3 For this parameter, the Permittee shall maintain at the facility a record of the Total Daily Flow and pH range for each operating day. The Permittee shall report on its DMR the “Average Daily Flow” and the “Maximum Daily Flow” and pH for each month and shall provide the record of the Total Daily Flow and pH range as an attachment to the DMR (Attachment D). Remarks: 1. Abbreviations used for units are as follows: gpd means gallons per day; mg/L means milligrams per liter; SU means Standard Units; µg/l means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit). 2. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. DRAFT PERMIT No. CT0030473 and SP0002464 Page 17 [Page 18] TABLE F Discharge Serial Number: DSN 104-1 Monitoring Location: 1 (External outfall) Wastewater Description: Make-up supply tank drain and overflow wastewaters Outfall Location: Latitude (41° 39’ 56”) and Longitude (71° 55’ 26”) Monitoring Location Description: Prior to discharging into the in-ground stormwater infiltration system located at the north end of the site Maximum Frequency of Discharge: Once per year Discharge is to: Infiltration into the groundwater of the Mill Brook watershed NET FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Instantaneous Sample/ Sample Type or MINIMUM CODE Monthly Daily Reporting Measurement to Limit or Reporting Measurement to LEVEL2 Limit Limit Frequency 1 be Reported Required Range Frequency be Reported (µg/l) Aluminum, Total 01105 mg/L NA NA NR NA --- Annually Grab 10.0 Boron 01022 mg/L NA NA NR NA --- Annually Grab Copper, Total 01042 mg/L NA NA NR NA --- Annual Grab 3.0 Flow, Maximum during 24-hr period 50047 gpd NA 250,000 Annually Total Daily Flow NA NR NA Iron, Total 01045 mg/L NA NA NR NA --- Annually Grab Lead, Total 01051 mg/L NA NA NR NA --- Annually Grab 1.0 pH 00400 S.U. NA NA NR NA 6.0 – 9.0 Annually Grab Phosphorus, Total 00665 mg/L NA NA NR NA --- Annually Grab 100.0 Zinc, Total 01092 mg/L NA NA NR NA --- Annually Grab 10.0 TABLE F FOOTNOTES AND REMARKS Footnotes: 1 The first entry in this column is the ‘Sample Frequency’. If a 'Reporting Frequency' does not follow this entry and the ‘Sample Frequency’ is more frequent than monthly, then the ‘Reporting Frequency’ is monthly. If the ‘Sample frequency’ is specified as monthly, or less frequent, then the ‘Reporting Frequency’ is the same as the ‘Sample Frequency’. 2 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Permittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 3 For this parameter, the Permittee shall maintain at the facility a record of the Total Daily Flow and pH range for each operating day. The Permittee shall report on its DMR the “Average Daily Flow” and the “Maximum Daily Flow” and pH for each month and shall provide the record of the Total Daily Flow and pH range as an attachment to the DMR (Attachment D). Remarks: 1. Abbreviations used for units are as follows: gpd means gallons per day; mg/L means milligrams per liter; SU means Standard Units; µg/l means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit). 2. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. DRAFT PERMIT No. CT0030473 and SP0002464 Page 18 [Page 19] TABLE G Intake Serial Number: DSN 101-H Monitoring Location: 0 (Intake for Cooling Water Intake Structure) Wastewater Description: Intake cooling water Intake Location: Latitude (41° 39’ 40”) and Longitude (71° 57’ 41”) Monitoring Location Description: Prior to the intake cooling water treatment at the Intake is from: Quinebaug River pH/temperature/turbidity monitoring location BTA Determination on Cooling Water Intake Structure in accordance with 40 CFR 125.90(b): Cylindrical wedgewire screen through screen design velocity of 0.25fps, and operation of a cooling tower, a closed cycle recirculating system as defined in 40 CFR 125.83. FLOW/TIME BASED MONITORING INSTANTANEOUS MONITORING NET MINI- PARAMETER DMR UNITS Average Maximum Sample/ Sample Type or Instantaneous Sample/ Sample Type or MUM CODE Monthly Daily Reporting Measurement to Limit or Reporting Measurement to LEVEL 2 Limit Limit Frequency 1 be reported Required Range Frequency be Reported (µg/l) Aluminum, Total 01105 mg/L NA NA NR NA --- Monthly Grab 10.0 Boron 01022 mg/L NA NA NR NA --- Monthly Grab Chromium, Total 01034 mg/L NA NA NR NA --- Monthly Grab 5.0 Copper, Total 01042 mg/L NA NA NR NA --- Monthly Grab 3.0 Flow rate (Average daily flow) 00056 gpd --- NA Monthly Total Daily Flow NA NR NA Flow, Maximum during 24-hr period 50047 gpd NA 893,000 Monthly Total Daily Flow NA NR NA Iron, Total 01045 mg/L NA NA NR NA --- Monthly Grab 100.0 Lead, Total 01051 mg/L NA NA NR NA --- Monthly Grab 1.0 pH, Minimum 61942 SU NA NA NR NA --- Monthly Grab pH, Maximum 61941 SU NA NA NR NA --- Monthly Grab Phosphorus, Total 00665 mg/L NA NA NR NA --- Monthly Grab 100.0 Temperature 00011 oF NA NA NR NA --- Monthly Instantaneous Zinc, Total 01092 mg/L NA NA NR NA --- Monthly Grab 10.0 TABLE G FOOTNOTES AND REMARKS Footnotes: 1 The first entry in this column is the ‘Sample Frequency’. If a 'Reporting Frequency' does not follow this entry and the ‘Samp le Frequency’ is more frequent than monthly, then the ‘Reporting Frequency’ is monthly. If the ‘Sample frequency’ is specified as monthly, or less frequent, then the ‘Reporting Frequency’ is the same as the ‘Sample Frequency’. 2 Refer to Section 6.3 of this permit. The minimum levels (“MLs”) identified in this table represent the highest acceptable MLs that shall be achieved by the Per mittee’s analytical methods. Actual MLs reported by the laboratory must be reported as a comment on the DMR. Detected concentrations less than the laboratory ML shall be reported on the DMR in accordance with Section 6.5. 3 For this parameter, the Permittee shall maintain at the facility a record of the Total Daily Flow and pH range for each opera ting day. The Permittee shall report on its DMR the “Average Daily Flow” and the “Maximum Daily Flow” and pH for each month and shall provide the record of the Total Daily Flow and pH range as an attachment to the DMR (Attachment D). Remarks: 1. Abbreviations used for units are as follows: gpd means gallons per day; mg/L means milligrams per liter; SU means Standard Units; oF means degrees Fahrenheit; µg/l means micrograms per liter. Other abbreviations are as follows: NA means Not Applicable; NR means Not Reportable (unless sampling is conducted relative to Section 5.4 of this permit). 2. If “---” is noted in the limits column in the table, this means that a limit is not specified but a value must be reported on the DMR. DRAFT PERMIT No. CT0030473 and SP0002464 Page 19 [Page 20] SECTION 6: SAMPLE COLLECTION, HANDLING AND ANALYTICAL TECHNIQUES 6.1 All samples shall be collected, handled, and analyzed in accordance with the methods approved under 40 CFR 136, unless another method is required under 40 CFR subchapter N or unless an alternative method has been approved in writing pursuant to 40 CFR 136.5. To determine compliance with limits and conditions established in this permit, monitoring must be performed using sufficiently-sensitive methods approved pursuant to 40 CFR 136 for the analysis of pollutants having approved methods under that part, unless a method is required under 40 CFR subchapter N or unless an alternative method has been approved in writing pursuant to 40 CFR 136.5. 6.2 All metals analyses identified in this permit shall refer to analyses for Total Recoverable Metal as defined in 40 CFR 136, unless otherwise specified. 6.3 The term Minimum Level (“ML”) refers to either the sample concentration equivalent to the lowest calibration point in a method or a multiple of the method detection limit (“MDL”). MLs may be obtained in several ways: They may be published in a method; they may be sample concentrations equivalent to the lowest acceptable calibration point used by the laboratory; or they may be calculated by multiplying the MDL in a method, or the MDL determined by a lab, by a factor of 3. The MLs specified in Section 5 Tables A - G represent the minimum concentrations at which quantification must be achieved and verified during the chemical analyses for the parameters identified in Section 5 Tables A – G. Analyses for these parameters must include check standards within ten percent of the specified ML or calibration points equal to or less than the specified ML. 6.4 The value of each parameter for which monitoring is required under this permit shall be reported to the maximum level of accuracy and precision possible, consistent with the requirements of this section of the permit. 6.5 Analyses for which quantification was verified to be below a ML, including non-detect, shall be reported as zero on the DMR for purposes of determining compliance with effluent limitations or conditions specified in this permit. The Permittee shall attach documentation demonstrating the ML of the analysis as an attachment to the DMR and identify the ML as a comment on the DMR. 6.6 It is a violation of this permit for a Permittee or his/her designated agent, to manipulate test samples in any manner, to delay sample shipment, or to terminate or to cause to terminate a toxicity test. Once initiated, all toxicity tests must be completed. 6.7 Analyses required under this permit shall be performed in accordance with Conn. Gen. Stat. Section 19a-29a. An “environmental laboratory”, as that term is defined in the referenced section, that is performing analyses required by this permit, shall be registered and have certification acceptable to the Commissioner, as such registration and certification is necessary. SECTION 7: AQUATIC TOXICITY TESTING 7.1 ACUTE TESTING REQUIREMENTS. The Permittee shall conduct acute aquatic toxicity testing for DSN 101-1 as follows: 7.1.1 TEST METHOD: Acute aquatic toxicity shall be performed as prescribed in the reference document Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms (EPA-821-R-02-012), or the most current version, with any exceptions or clarifications noted below. DRAFT PERMIT No. CT0030473 and SP0002464 Page 20 [Page 21] 7.1.2 SAMPLE COLLECTION AND HANDLING: 7.1.2.1 Composite samples shall be chilled as they are collected. Grab samples shall be chilled immediately following collection. Samples shall be held at 0-6 °C until aquatic toxicity testing is initiated. 7.1.2.2 Effluent samples shall not be dechlorinated, filtered, or modified in any way prior to testing for acute aquatic toxicity unless specifically approved in writing by the Commissioner for monitoring at this facility. 7.1.2.3 Tests for acute aquatic toxicity shall be initiated within 36 hours of sample collection. 7.1.3 TEST SPECIES AND TEST DURATION: Monitoring for aquatic toxicity to determine compliance with the acute toxicity limits in this permit shall be conducted as follows: 7.1.3.1 For 48-hours utilizing neonatal Daphnia pulex (less than 24-hours old). 7.1.3.2 For 48-hours utilizing larval Pimephales promelas (1-14 days old with no more than 24-hours range in age). 7.1.4 ACUTE ENDPOINT: Survival at 48-hours measured by NOAEL. 7.1.5 TEST CONDITIONS: 7.1.5.1 Tests for acute aquatic toxicity shall be conducted as prescribed for static non-renewal tests. 7.1.5.2 Pass/fail and single concentration tests shall be conducted at a specified Critical Test Concentration (CTC) equal to the acute toxicity effluent limit, or 100% in the case of monitoring only conditions, as prescribed in Section 22a-430-3(j)(7)(A)(i) of the RSCA. Five replicates of undiluted effluent and five replicates of effluent diluted to the CTC shall be employed in the test. Three replicate control test chambers containing dilution water only shall also be employed in the test. 7.1.5.3 Synthetic freshwater prepared with deionized water adjusted to a hardness of 50 mg/L (±5 mg/L) as CaCO3 shall be used as dilution water. 7.1.5.4 Organisms shall not be fed during the tests. 7.1.5.5 Copper nitrate shall be used as the reference toxicant. 7.1.5.6 Dissolved oxygen, pH, and temperature shall be measured in the control and in all test concentrations at the beginning of the test, daily thereafter, and at test termination. 7.1.5.7 Specific conductance, pH, alkalinity, hardness, and total residual chlorine shall be measured in the undiluted effluent sample and in the dilution (control) water at the beginning of the test and at test termination. If total residual chlorine is not detected at test initiation, it does not need to be measured at test termination. DRAFT PERMIT No. CT0030473 and SP0002464 Page 21 [Page 22] 7.1.6 CHEMICAL ANALYSIS: All effluent samples used in the acute toxicity test shall, at a minimum, be analyzed and results reported in accordance with the provisions listed in Section 5 Table B and Section 6.1 of this permit for the following parameters identified on Section 5 Table B of the permit. 7.1.7 TEST ACCEPTABILITY CRITERIA: For the test results to be acceptable, control survival must equal or exceed 90%. If the laboratory control fails to meet test acceptability criteria for either of the test organisms at the end of the respective test period, then the test is considered invalid and the test must be repeated with a newly collected sample in accordance with Section 9.4. 7.1.8 TEST COMPLIANCE: Compliance with limits on Acute Toxicity shall be determined as follows: 7.1.8.1 For limits expressed as ana NOAEL value, compliance shall be demonstrated when the results of a valid single concentration or pass/fail acute aquatic toxicity test indicates there is greater than 50% survival in the undiluted effluent and 90% or greater survival in the effluent at the specified CTC. 7.1.9 REPORTING: Results of acute toxicity monitoring shall be documented on an Aquatic Toxicity Monitoring Report (“ATMR”) and reported to the Commissioner by the last day of the month following the month in which samples are collected in accordance with Section 8.2 of this permit. The report shall include the items identified in Section 8.2 of this permit. Endpoints to be reported are: 48-hour LC50 and NOAEL. 7.2 CHRONIC TESTING REQUIREMENTS. The Permittee shall conduct chronic toxicity testing for DSN 001-1 as follows: 7.2.1 TEST METHOD: Chronic aquatic toxicity testing shall be performed as prescribed in the reference document Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Water to Freshwater Organisms, EPA-821-R-02-013, or the most current version, with the following exceptions or clarifications noted below. 7.2.2 SAMPLE COLLECTION AND HANDLING: 7.2.2.1 Composite samples shall be chilled as they are being collected. Samples shall be held at 0-6 °C until chronic aquatic toxicity testing is initiated. 7.2.2.2 Effluent samples shall not be dechlorinated, filtered, or modified in any way prior to testing for chronic aquatic toxicity unless specifically approved in writing by the Commissioner for monitoring at this facility. 7.2.2.3 Tests for chronic aquatic toxicity shall be initiated within 36 hours of sample collection. 7.2.3 TEST SPECIES AND TEST DURATION: Monitoring for chronic aquatic toxicity to determine compliance with the chronic toxicity limits/conditions in the permit shall be conducted as follows: 7.2.3.1 For seven days utilizing neonatal Ceriodaphnia dubia (less 24-hours old) 7.2.3.2 For seven days utilizing newly-hatched Pimephales promelas (less 24-hours old). DRAFT PERMIT No. CT0030473 and SP0002464 Page 22 [Page 23] 7.2.4 CHRONIC ENDPOINTS: 7.2.4.1 Ceriodaphnia dubia: Survival and Reproduction 7.2.4.2 Pimephales promelas: Survival and Growth 7.2.5 DILUTION WATER: Quinebaug River water shall be collected upstream of the area influenced by the discharge shall be used as site control water (0% effluent) and dilution water in the toxicity tests. The Permittee shall document the dilution water sampling location by providing coordinates and/or a map of the location. 7.2.6 TEST CONDITIONS: 7.2.6.1 Testing for chronic aquatic toxicity shall be conducted as prescribed in the reference document for static daily renewal tests. 7.2.6.2 Daily composite samples of the discharge and grab samples of the Quinebaug River for use as site water and dilution water shall be collected on: Day 1 of the test (for test initiation and renewal on Day 2 of the test); Day 3 of the test (for test solution renewal on Day 3 and Day 4 of the test); and on Day 5 of the test, (for test solution renewal on Day 5, Day 6, and Day 7 of the test). Samples shall not be dechlorinated, pH or hardness adjusted, or chemically altered in any way. 7.2.6.3 Test concentrations shall be comprised of a minimum of five dilutions (100%, 64%, 32%, 16%, 8%, and 4% effluent), laboratory control water, and site dilution water. 7.2.6.4 Dissolved oxygen, pH, and temperature shall be measured in each sample of effluent and the Quinebaug River water sample prior to and immediately following renewal of the test solutions. 7.2.6.5 Synthetic freshwater prepared with deionized water adjusted to a hardness of 50 mg/l (±5 mg/l) as CaCO3 prepared as described in Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms (EPA-821-R-02-013) shall be used as laboratory control water. 7.2.7 CHEMICAL ANALYSIS: Chemical analysis for the parameters identified in Section 5 Table C and Section 6.1 of the permit shall be conducted on an undiluted aliquot of each effluent sample and each sample of Quinebaug River used in the test. The chemical analysis shall be analyzed, and results reported in accordance with the provisions listed in Section 5 Table C and Section 6.1 of the permit. 7.2.8 TEST ACCEPTABILITY CRITERIA: If the laboratory control fails to meet test acceptability criteria specified in the reference document for either of the test organisms at the end of the respective test period, then the test is considered invalid and the test must be repeated. 7.2.9 REPORTING: A report detailing the results of the chronic toxicity monitoring shall be documented on an ATMR and submitted to the Commissioner by the last day of the month following the month in which samples are collected in accordance with Section 8.2 of this permit. The report shall include the items identified in Section 8.2 of this permit. Endpoints to be reported are: 48-hour LC50 (survival), 7-day LC50 (survival), 7-day C-NOEC (survival), 7-day C-LOEC (survival), 7-day C-NOEC (growth), 7-day C-LOEC (growth), 7- DRAFT PERMIT No. CT0030473 and SP0002464 Page 23 [Page 24] day C-NOEC (reproduction), 7-day C-LOEC (reproduction), 7-day IC25 (growth and reproduction). SECTION 8: REPORTING REQUIREMENTS 8.1 The results of chemical analyses and any aquatic toxicity test required by this permit shall be submitted electronically using NetDMR. Monitoring results shall be reported at the monitoring frequency specified in this permit. Any monitoring required more frequently than monthly shall be reported on an attachment to the DMR, and any additional monitoring conducted in accordance with 40 CFR 136, or another method required for an industry-specific waste stream under 40 CFR subchapter N, or other methods approved by the Commissioner, shall also be included on the DMR, or as an attachment, if necessary, and the results of such monitoring shall be included in the calculation and reporting of the data submitted in the DMR. Calculations for all limitations which require averaging of measurements shall utilize an arithmetic mean unless otherwise specified by the Commissioner in the permit. All aquatic toxicity reports shall also be included as an attachment to the DMR. A report shall also be included with the DMR which includes a detailed explanation of any violations of the limitations specified. DMRs, attachments, and reports, shall continue to be submitted electronically in accordance with Section 8.5 below. However, if the DMRs, attachments, and reports are required to be submitted in hard copy form, they shall be received at this address by the last day of the month following the month in which samples are collected: Bureau of Materials Management and Compliance Assurance Water Permitting and Enforcement Division (Attn: DMR Processing) Connecticut Department of Energy and Environmental Protection 79 Elm Street, Hartford, CT 06106-5127 8.2 The ATMR associated with aquatic toxicity monitoring shall include all applicable items identified in Section 12 of EPA-821-R-02-012 and in Section 10 of EPA-821-R-02-013 (Freshwater), including complete and accurate aquatic toxicity test data, including percent survival of test organisms in each replicate test chamber, LC50 values and 95% confidence intervals for definitive test protocols, and all supporting chemical/physical measurements performed in association with any aquatic toxicity test, including measured daily flow and hours of operation for the 30 consecutive operating days prior to sample collection. The ATMR shall be submitted electronically as an attachment to the DMR and via email to: DEEP.IndustrialWETReports@ct.gov , by the last day of the month following the month in which the samples are collected. 8.3 If this permit requires monitoring of a discharge on a calendar basis (e.g., monthly, quarterly, etc.), but a discharge has not occurred within the frequency of sampling specified in the permit, the Permittee must submit the DMR and ATMR, as scheduled, indicating “NO DISCHARGE”. For those permittees whose required monitoring is discharge dependent (e.g., per batch), the minimum reporting frequency is monthly. Therefore, if there is no discharge during a calendar month for a batch discharge, a DMR must be submitted indicating such by the end of the following month. 8.4 NetDMR Reporting Requirements: The Permittee shall report electronically using NetDMR, a web-based tool that allows permittees to electronically submit DMRs and other required reports through a secure internet connection. The Permittee and/or the signatory authority shall electronically submit DMRs required under this permit to the Commissioner using NetDMR in satisfaction of the DMR submission requirements of Sections 5, 6, and 9 of this permit. All sampling and monitoring records required under the permit, including any monitoring conducted more frequently than monthly or any additional monitoring conducted in DRAFT PERMIT No. CT0030473 and SP0002464 Page 24 [Page 25] accordance with 40 CFR 136, shall be submitted to the Commissioner as an electronic attachment to the DMR in NetDMR. The Permittee shall also electronically file any written report of noncompliance described in Section 9 of this permit as an attachment in NetDMR. DMRs shall be submitted electronically to the Commissioner no later than the last day of the month following the completed reporting period. NetDMR is accessed from: http://www.epa.gov/netdmr. SECTION 9: RECORDING AND REPORTING OF VIOLATIONS, ADDITIONAL TESTING REQUIREMENTS 9.1 Noncompliance Notifications: 9.1.1 In accordance with Section 22a-430-3(j)(8), 22a-430-3(j)(11)(D), 22a-430-3(k)(4), and 22a- 430-3(i)(3) of the RSCA, the Permittee shall notify the Commissioner of the following actual or anticipated noncompliance with the terms or conditions of this permit within two hours of becoming aware of the circumstances. All other actual or anticipated violations of the permit shall be reported to the Commissioner within 24 hours of becoming aware of the circumstances: 9.1.1.1 A noncompliance that is greater than two times an effluent limitation; 9.1.1.2 A noncompliance of any minimum or maximum daily limitation or excursion beyond a minimum or maximum daily range; 9.1.1.3 Any condition that may endanger human health or the environment, including but not limited to noncompliance with whole effluent toxicity WET limitations; 9.1.1.4 Any condition that may endanger the operation of a POTW, including sludge handling and disposal; 9.1.1.5 A failure or malfunction of monitoring equipment used to comply with the monitoring requirements of this permit; 9.1.1.6 Any actual or potential bypass of the Permittee’s collection system or treatment facilities; or 9.1.1.7 Expansions or significant alterations of any wastewater collection, treatment facility, or its method of operation for the purpose of correcting or avoiding a permit violation. 9.1.2 Notifications shall be submitted via the Commissioner’s online Noncompliance Notification Form: https://portal.ct.gov/deep/water-regulating-and-discharges/industrial- wastewater/compliance-assistance/notification-requirements. 9.1.3 Within five days of any notification of noncompliance in accordance with Sections 9.1.1.1 through 9.1.1.6 of this permit, the Permittee shall submit a follow-up report using the Commissioner’s online Noncompliance Follow-up Report Form: https://portal.ct.gov/deep/water-regulating-and-discharges/industrial- wastewater/compliance-assistance/notification-requirements. The follow-up report shall contain, at a minimum, the following information: (i) A description of the noncompliance and its cause; (ii) the period of noncompliance, including DRAFT PERMIT No. CT0030473 and SP0002464 Page 25 [Page 26] exact dates and times; (iii) if the noncompliance has not been corrected, the anticipated time it is expected to continue; and (iv) steps taken or planned to correct the noncompliance and reduce, eliminate and prevent recurrence of the noncompliance. 9.1.4 Within 30 days of any notification of facility modifications reported in accordance with Section 9.1.1.7 of this permit, the Permittee shall submit a written follow-up report by submitting a “Facility and Wastewater Treatment System Modification Request for Determination” for the review and approval of the Commissioner. The report shall fully describe the changes made to the facility and reasons therefor. 9.1.5 Notification of an actual or anticipated noncompliance or facility modification does not stay any term or condition of this permit. 9.2 In accordance with Section 22a-430-3(j)(11)(E) of the RSCA, the Permittee shall notify the Commissioner within 72 hours and in writing within 30 days when he or she knows or has reason to believe that the concentration in the discharge of any substance listed in the application, or any toxic substance as listed in Appendix B or D of RSCA Section 22a-430-4, has exceeded or will exceed the highest of the following levels: (1) One hundred micrograms per liter; (2) Two hundred micrograms per liter for acrolein and acrylonitrile, five hundred micrograms per liter for 2,4-dinitrophenol and for 2-methyl-4, 6-dinitrophenol; and one milligram per liter for antimony; (3) An alternative level specified by the Commissioner, provided such level shall not exceed the level which can be achieved by the Permittee’s treatment system; or (4) A level two times the level specified in the Permittee’s application. 72 hour initial notifications shall be submitted via the Commissioner’s online Noncompliance Notification Form. 30 day follow-up reports shall be submitted via the Commissioner’s online Noncompliance Follow-up Report Form. The Forms are available at the Commissioner’s website, here: https://portal.ct.gov/deep/water-regulating-and-discharges/industrial-wastewater/compliance- assistance/notification-requirements. 9.3 In addition to any other written reporting requirements, the Permittee shall report any instances of noncompliance with this permit with its DMR. Such reporting shall be due no later than the last day of the month following the reporting period in which the noncompliant event occurred. The information provided in the DMR shall include, at a minimum: the type of violation, the duration of the violation, the cause of the violation, and any corrective action(s) or preventative measure(s) taken to address the violation. 9.4 If any sample analysis indicates that an aquatic toxicity effluent limitation in Section 5 of this permit has been exceeded, or that the test was invalid, another sample of the effluent shall be collected and tested for aquatic toxicity and associated chemical parameters, as described above in Sections 5 and 7. The exceedance or invalid test shall be reported to Commissioner in accordance with Section 9.1. The results shall be submitted to the Commissioner within 30 days of the exceedance or invalid test. The results and the associated ATMR shall be reported in accordance with Sections 5 and 8.2 of the permit. Results of all tests, whether valid or invalid, shall be reported. If more than one toxicity sample is collected during a single month, report subsequent WET and chemistry results as an attachment to the month’s DMR. 9.5 If any two consecutive test results or any three test results in a twelve-month period indicate that an aquatic toxicity limit has been exceeded, the Permittee shall immediately take all reasonable steps to eliminate toxicity wherever possible and shall also submit a report, for the review and written approval of the Commissioner, which describes in detail the steps taken or that shall be taken to eliminate the toxic impacts of the discharge on the receiving water and it shall also include a DRAFT PERMIT No. CT0030473 and SP0002464 Page 26 [Page 27] proposed schedule for implementation. Such report shall be submitted in accordance with the timeframe set forth in Section 22a-430-3(j)(10)(C) of the Regs. Conn. State Agencies. The Permittee shall implement all actions in accordance with the approved report and schedule. SECTION 10: COMPLIANCE SCHEDULE 10.1 pH EFFLUENT LIMITATIONS COMPLIANCE. The Permittee shall achieve compliance with the pH effluent limitations and in Table A of Section 5 of this permit, as soon as possible, but in no event later than 12 months after the effective date of this permit in accordance with the following: 10.1.1 SCOPE OF STUDY. On or before 90 days after the date of issuance of this permit, the Permittee shall submit for the Commissioner's review and written approval a comprehensive plan and thorough report which describes and evaluates alternative actions which may be taken by the Permittee to achieve compliance with the pH limitations in Section 5 of this permit. Such report shall: 10.1.1.1 Evaluate alternative actions to achieve compliance with Section 5 limits including, but not limited to, pollutant source reduction, process changes/innovations, chemical substitutions, recycle and zero discharge systems, water conservation measures, and other internal and/or end-of-pipe treatment technologies; upstream and downstream sampling locations; 10.1.1.2 State in detail the most expeditious schedule for performing each alternative; 10.1.1.3 List all permits and approvals required for each alternative, including but not limited to any permits required under Sections 22a-32, 22a-42a, 22a-342, 22a-361, 22a-368 or 22a-430 of the CGS; 10.1.1.4 Propose a preferred alternative or combination of alternatives with supporting justification; and 10.1.1.5 Propose a preferred alternative or combination of alternatives with supporting justification; and 10.1.1.6 Propose a detailed program and schedule, including the start and anticipated end dates, to perform all actions required by the preferred alternative including but not limited to a schedule for submission of engineering plans and specifications on any internal and/or end of pipe treatment facilities, start and completion of any construction activities related to any treatment facilities, and applying for and obtaining all permits and approvals required for such actions. 10.2 THERMAL VERIFICATION STUDY. Pursuant to Section 316(a) of the Federal Water Pollution Control Act, 33 U.S.C. § 1326(a) regarding the thermal component of the discharge, the Permittee shall comply with the following to verify that the thermal discharge from DSN 101-1 will not cause or contribute to an instream water quality violation of the ambient daily maximum and maximum allowable increase in temperature of 4oF: 10.2.1 SCOPE OF STUDY. On or before six (6) months after the effective date of the permit, the Permittee shall submit for the Commissioner's review , a scope of study for the thermal verification required in Section 10.2 of this permit. The scope of study shall provide all necessary details on how the study will be performed and shall include a schedule that identifies study commencement and completion dates. The scope of study shall include at a DRAFT PERMIT No. CT0030473 and SP0002464 Page 27 [Page 28] minimum: 10.2.1.1 In situ sampling during summer (July – September) and winter (January – March) with vertical plume monitoring, and summer mapping occurring at or near 7Q10 conditions; 10.2.1.2 Upstream and downstream sampling locations; 10.2.1.3 Hydrographic and real time temperature surveys; and 10.2.1.4 Thermal plume mappings. 10.2.1.5 Record of both the rate of discharge (gph) during the study, and total daily flow for each mapping; 10.2.1.6 Record of the river flow during the mapping obtained from the USGS Streamgage No. 0112700 in Jewett City, including the hydrographs; and. 10.2.1.7 Identification of representative important species (“RIS”). RIS are species which are representative, in terms of their biological needs, of a balanced, indigenous community of shellfish, fish, and wildlife in the body of water into which the thermal discharge is made. Below is a list of recommended criteria for identifying RIS: 1. Species listed in the WQS as requiring protection. 2. Species listed as threatened and endangered. 3. Thermally sensitive species in the local area, including those species near the northern or southern boundaries of their natural ranges. 4. Species that are valuable for commercial or recreational activities. 5. Species that are critical to the structure and function of the ecological system, i.e., those that are necessary in the food chain or as habitat formers for the species included in the criteria above. 6. Species that are potentially capable of becoming nuisance species 7. Species that are representative of the thermal requirements of important species but which themselves are not important. 10.2.2 FIELD VERIFICATION. On or before two (2) years after the Department’s concurrence of the scope of study, the Permittee shall conduct a field verification study of the thermal discharge impact to the Quinebaug River. 10.2.3 REPRESENTATIVE IMPORTANT SPECIES. On or before two (2) years after the Department’s concurrence of the scope of study, the Permittee shall determine the thermal thresholds such as the acute and chronic lethal thermal sensitivity limits, and the optimal temperature ranges, for the different life stages of the selected RIS. 10.2.4 REPORT SUBMITTAL. On or before four (4) months from completing the field verification study, the Permittee shall submit a Thermal Verification Report describing the results of this study for the Commissioner’s review. The study shall include but not be limited to all in situ data collected and analyzed in an electronic and editable format, thermal plume mapping reflecting the current outfall release cross-sectional area, identification of RIS and the applicable thermal thresholds, and potential aquatic impacts within wetlands and watercourse in the thermal plume. The thermal plume mapping shall include, at a minimum: DRAFT PERMIT No. CT0030473 and SP0002464 Page 28 [Page 29] 10.2.4.1 Map of the nearfield area, circumscribed by a radial distance extending outward from the location of the discharge (DSN001-1) into the receiving water body, at a scale of no greater than 750 feet per inch. Such map shall also delineate the location of any watercourses, discharges, designated tidal wetlands, and structural features such as bridges and culverts. The cross-sectional bathymetry of the Quinebaug River shall be plotted, including bathymetry for any areas where the thermal data is different than expected; 10.2.4.2 Thermal isotherms delineating the areal extent of the plume equivalent to a ΔT of 4oF and a maximum temperature of 85°F or ambient temperature, if ambient temperature is above 85°F in increments of 1oF. Isotherms shall be labeled for both maximum temperature and maximum temperature increase beginning at the outfall and at ΔT of 1.5 °F and 4oF intervals. Isotherms should be labeled from point of discharge until the thermal component of that plume has been reduced to ambient temperatures. Nearfield temperature increases should be well documented to determine the localized effect of high temperature discharges; and 10.2.4.3 Measurements will be taken during the summer months (July – September) and winter months (January - March), during a normal operating day; 10.2.4.4 The report should compare conditions on the days of the study to 7Q10 and extrapolate the plume contours expected under 7Q10 conditions; and 10.2.4.5 Sampling and water quality data should be provided as a excel spreadsheet, and contour lines, monitoring locations, and bathymetry should be provided as an Arc GIS Pro geospatial project using the State Plane Connecticut FIPS coordinate system. 10.3 STATUS REPORTS. The Permittee shall submit to the Commissioner semi-annual status reports on June 30th and December 31st of each year, beginning sixty days after the date of concurrence of the reports referenced in Sections 10.1.1 and 10.2.1 above. Status reports shall include the following: 10.3.1 A description of the work performed by the Permittee during the past six (6) months towards compliance with Sections 10.1, 10.2.2 and 10.2.3 above; 10.3.2 An assessment of whether the Permittee is on schedule to comply with the compliance deadline; 10.3.3 If the Permittee is not on-track to comply with the compliance deadline, the steps the Permittee will take to comply; and 10.3.4 Status reports of Sections 10.1, 10.2.2 and 10.2.3 shall include the start and anticipated end dates of the studies fieldwork and anticipated report submission date. 10.4 PROJECT COMPLETION CERTIFICATION. The Permittee shall perform the approved actions in accordance with the approved schedule. Within fourteen (14) days after completing such actions, the Permittee shall certify to the Commissioner in writing that the actions have been completed as reviewed/approved. 10.5 COMMISSIONER APPROVAL. The Permittee shall use best efforts to submit to the Commissioner all documents required by this section of the permit in a complete and approvable form. If the Commissioner notifies the Permittee that any document or other action is deficient, and DRAFT PERMIT No. CT0030473 and SP0002464 Page 29 [Page 30] does not approve it with conditions or modifications, it is deemed disapproved, and the Permittee shall correct the deficiencies and resubmit it within the time specified by the Commissioner or, if no time is specified by the Commissioner, within thirty days of the Commissioner's notice of deficiencies. In approving any document or other action under this Compliance Schedule, the Commissioner may approve the document or other action as submitted or performed or with such conditions or modifications as the Commissioner deems necessary to carry out the purposes of this section of the permit. Nothing in this paragraph shall excuse noncompliance or delay. 10.6 DATES. The date of submission to the Commissioner of any document required by this section of the permit shall be the date such document is received by the Commissioner. The date of any notice by the Commissioner under this section of the permit, including but not limited to notice of approval or disapproval of any document or other action, shall be the date such notice is personally delivered or the date three days after it is mailed by the Commissioner, whichever is earlier. Except as otherwise specified in this permit, the word "day" as used in this section of the permit means calendar day. Any document or action which is required by this section only of the permit, to be submitted, or performed, by a date which falls on, Saturday, Sunday, or, a legal Connecticut or federal holiday, shall be submitted or performed on or before the next day which is not a Saturday, Sunday, or legal Connecticut or federal holiday. 10.7 NOTIFICATION OF NONCOMPLIANCE. Except as otherwise provided in this permit, in the event that the Permittee becomes aware that it did not or may not comply, or did not or may not comply on time, with any requirement of this section of the permit or of any document required hereunder, the Permittee shall immediately notify the Commissioner and shall take all reasonable steps to ensure that any noncompliance or delay is avoided or, if unavoidable, is minimized to the greatest extent possible. In so notifying the Commissioner, the Permittee shall state in writing the reasons for the noncompliance or delay and propose, for the review and written approval of the Commissioner, dates by which compliance will be achieved, and the Permittee shall comply with any dates that may be approved in writing by the Commissioner. Notification by the Permittee shall not excuse noncompliance or delay, and the Commissioner’s approval of any compliance dates proposed shall not excuse noncompliance or delay unless specifically so stated by the Commissioner in writing. 10.8 NOTICE TO COMMISSIONER OF CHANGES. Within fifteen (15) days of the date the Permittee becomes aware of a change in any information submitted to the Commissioner under this section of the permit, or that any such information was inaccurate or misleading or that any relevant information was omitted, the Permittee shall submit the correct or omitted information to the Commissioner. 10.9 SUBMISSION OF DOCUMENTS. Any document, other than a discharge monitoring report, required to be submitted to the Commissioner under this section of the permit shall, unless otherwise specified in writing by the Commissioner, be directed to: DEEP.IndustrialNPDESCompliance@ct.gov with the subject line "Plainfield Renewable Energy, LLC. – CT0030473 and SP0002464" This permit is hereby issued on ________________________________ JENNIFER PERRY, P.E. Bureau Chief JP/OF DRAFT PERMIT No. CT0030473 and SP0002464 Page 30 [Page 31] National Pollutant Discharge Elimination System Permit Factsheet NPDES Permit Summary Applicant Plainfield Renewable Energy, LLC Permit No. CT0030473 Application No. 201801971 Date Application Received February 28, 2018 Location Address 12 Mill Brook Road, Plainfield, CT 06374 Facility Contact Mark Boucher, EHS Compliance Coordinator Office Phone: (860) 457-9307 Email: mboucher@plainfieldre.com Mailing Address 12 Mill Brook Road, Plainfield, CT 06374 DMR Contact Mark Boucher, EHS Compliance Coordinator Office Phone: (860) 457-9307 Email: mboucher@plainfieldre.com Secretary of State Business ID 0853528 Permit Term 5 Years Permit Category National Pollutant Discharge Elimination System (“NPDES”) Minor (“MI”) SIC & NAICS Code(S) 4911 & 221112 (Biomass Electric Power Generation) Applicable Effluent Guidelines None Permit Type Reissuance Ownership Private Receiving Water DSN 101: Quinebaug River DSN 102, 103 & 104: Groundwater in the Mill Brook watershed Waterbody Segment Id’s CT3700-00_02 Waterbody Classification DSN 101: Surface water Class B DSN 102 & 103: Ground water Class GA-Impaired DSN 104: Ground water Class GA Discharge Locations DSN 101: 41o 39′ 35", -71o 57′ 49" (Latitude, Longitude) DSN 102 & 103: 41o 39′ 42", -71o 55′ 28" DSN 104: 41o 39′ 56", -71o 55′ 26" Water Intake Location Intake SN 101H: 41o 39′ 40", -71o 57′ 41" (Latitude, Longitude) Compliance Schedule/Actions Yes (Thermal verification study) Staff Engineer Oluwatoyin Fakilede, Environmental Engineer 3 Phone: (860) 418-5986; E-Mail: Oluwatoyin.fakilede@ct.gov Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 1 of 43 [Page 32] Table of Contents Section 1 Facility Summary ............................................................................................................ 4 1.1 Permit Fees ...................................................................................................................... 4 1.1.1 Application Fee: .............................................................................................................. 4 1.1.2 Annual Fee: ..................................................................................................................... 4 1.2 Application Submittal Information ........................................................................................ 4 1.3 Other Permits ......................................................................................................................... 5 1.4 Facility Description ............................................................................................................... 5 1.5 Description of Industrial Process ........................................................................................... 6 1.5.1 DSN 101-1 ...................................................................................................................... 6 1.5.2 DSN 102-1 ...................................................................................................................... 7 1.5.3 DSN 103-1 ...................................................................................................................... 7 1.5.4 DSN 104-1 ...................................................................................................................... 7 1.5.5 Intake SN 101H ............................................................................................................... 7 1.5.6 DSN 105-1 ...................................................................................................................... 7 1.6 Treatment System Description .............................................................................................. 7 1.7 Facility Changes .................................................................................................................... 8 1.8 Compliance History ............................................................................................................... 9 1.8.1 Discharge Monitoring Report Review ............................................................................ 9 1.8.2 Notice of Violation ......................................................................................................... 9 1.8.3 Previous NPDES Permit Compliance Schedule ........................................................... 10 1.9 General Issues Related to the Application ........................................................................... 11 1.9.1 Federally Recognized Indian Land ............................................................................... 11 1.9.2 Coastal Area/Coastal Boundary .................................................................................... 11 1.9.3 Endangered Species ...................................................................................................... 11 1.9.4 Aquifer Protection Areas .............................................................................................. 11 1.9.5 Conservation or Preservation Restriction ..................................................................... 11 1.9.6 Public Water Supply Watershed ................................................................................... 11 Section 2 Receiving Water Body Information .............................................................................. 12 2.1 Designated Uses .................................................................................................................. 12 2.2 Applicable Total Maximum Daily Load (“TMDL”) ........................................................... 12 2.2.1 Phosphorus .................................................................................................................... 12 Section 3 Permit Conditions and Effluent Limitations ................................................................. 15 Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 2 of 43 [Page 33] 3.1 Basis for Limits ................................................................................................................... 15 3.2 Pollutants of Concern .......................................................................................................... 15 3.3 Technology Based Effluent Guidelines ............................................................................... 17 3.4 Zone of Influence ................................................................................................................. 18 3.5 Reasonable Potential Analysis ............................................................................................. 18 3.6 Whole Effluent Toxicity ...................................................................................................... 19 3.7 Water Quality Based Effluent Limitations (WQBELS) ...................................................... 19 3.8 Comparison of Limits .......................................................................................................... 20 3.9 Sampling Frequency, Type, and Reporting ......................................................................... 21 3.10 Effluent Limitations and Monitoring Requirements ......................................................... 21 3.11 Other Permit Conditions .................................................................................................... 27 3.12 Compliance Schedule ........................................................................................................ 27 3.13 Antidegradation ................................................................................................................. 27 3.14 Anti-Backsliding ................................................................................................................ 28 3.15 Categorical Discharge Conditions ..................................................................................... 28 3.16 Cooling Water Intake Structure Section 316(b) ................................................................ 28 3.18 Variances and Waivers ...................................................................................................... 30 3.19 E-Reporting ....................................................................................................................... 34 Section 4 Summary of New Permit Conditions and Limits from the Previous Permit ................. 35 Section 5 Public Participation Procedures .................................................................................... 36 5.1 Information Requests ........................................................................................................... 36 5.2 Public Comment .................................................................................................................. 36 Appendix A: Zone of Influence Determination Memo ............................................................. 37 Appendix B: Reasonable Potential Analysis and Water Quality Based Limits Calculations ... 41 Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 3 of 43 [Page 34] Section 1 Facility Summary 1.1 Permit Fees 1.1.1 Application Fee: Filing Fee Invoice No.: DEP297437 Amount: $ 1,300.00 Date Paid: 2/28/2018 Processing Fee Invoice No.: DEP299637 Amount: $ 10,225.00 Date Paid: 4/24/2018 Processing Fee Invoice No.: DEP310412 Amount: $ 7,350.00 Date Paid: 4/25/2018 1.1.2 Annual Fee: Wastewater Category Annual Fee (per Regs. Conn. State Agencies Fee Flow Category DSN (per Regs. Conn. State sec. 22a-430-7) Gallons per day (“gpd”) Agencies sec. 22a-430-7 and CGS sec. 22a-6f) Non-contact cooling water 101 (“NCCW”) from steam generating > 50,000 $ 8,425.00 power plant Hydrostatic pressure testing > 50,000 102 $ 2,290.00 wastewater Hydrostatic pressure testing > 50,000 103 --- wastewater NCCW make up supply tank drain > 50,000 104 TOTAL AMOUNT $ 10,715.00 1.2 Application Submittal Information On February 28, 2018, the Department of Energy and Environmental Protection (“DEEP”) received an application (Application No. 201801971) from Plainfield Renewable Energy, LLC (“the Permittee”, “the Applicant”, “the facility”) located in Plainfield, CT06374, for the renewal of its NPDES permit (Permit No. CT0030473) and state permit (Permit No. SP0002464), expiring on August 29, 2018 (“the previous permits”). Consistent with the requirements of Section 22a-6g of the Connecticut General Statutes (“Conn. Gen. Stat.”), the Permittee published a Notice of Permit Application in the Norwich Bulletin on February 20, 2018. On April 26, 2018, the application was determined to be timely and administratively sufficient. The Permittee seeks authorization for the following in Application No. 201801971: Proposed Proposed Proposed DSN Average Maximum Waste Treatment Discharge Daily Flow Daily Streams Type to (gpd) Flow (gpd) NCCW (cooling Filtration, chlorine 101 126,103 173,571 tower removal using Quinebaug blowdown) sodium bisulfite River and pH adjustment Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 4 of 43 [Page 35] Proposed Proposed Proposed DSN Average Maximum Waste Treatment Discharge Daily Flow Daily Streams Type to (gpd) Flow (gpd) 102 NA 225,000 Fire pump test No treatment Infiltration into wastewater groundwater 103 NA 225,000 Fire hydrant test No treatment Infiltration into wastewater groundwater 104 NA 250,000 Make up supply No treatment Infiltration into tank drain groundwater Intake Design Intake Flow Intake Water Description Source Water (gpd) 001-H 893,000 Intake cooling water Quinebaug River This permit was previously assigned two permit numbers: Permit Nos. CT0030473 and SP0002464. Groundwater discharges from DSNs 102, 103, and 104 were associated with Permit No. SP0002464. Permit No. SP0002464 has been terminated and removed from this permit. All discharges, including DSNs 102, 103, and 104 are now covered under Permit No. CT0030473. 1.3 Other Permits The Permittee has permit coverage for other wastewater and stormwater discharges under the following permitting mechanisms: • Stormwater from the site is permitted under the “General Permit for Stormwater Activity Associated with Industrial Activities” (GSI002655); and • Air compressor condensate, boiler blowdown and building maintenance wastewaters from the site are discharged to the Plainfield Publicly Owned Treatment Works (“POTW”) under coverage of the “General permit for Discharges from Miscellaneous Industrial Users (MIU GP)”. The Permittee also has a water diversion permit (DIV-200603081) that authorizes the withdrawal of 893,000 gallons per day water from the Quinebaug River. 1.4 Facility Description Plainfield Renewable Energy, LLC (“PRE”) is a 37.5 MW (megawatt) wood gasification biomass power plant facility in Plainfield. The power plant is located at 12 Mill Brook Road in Plainfield, Connecticut, at the intersection of Mill Brook Road and Norwich Road. The pumphouse for the intake is located at 114 Packer Road in Canterbury, Connecticut , about two miles away from the power plant. The Permittee has maintained a NPDES permit since 2008. The Mill Brook facility consists of two (3) separate operational units: 1. A "volume reduction plant" (VRP) where wood chips are received through a double truck scale system, unloaded into hoppers, conveyed, handled, stored in piles located in a dedicated Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 5 of 43 [Page 36] area (outdoors and/or under a canopy structure), screened and subsequently conveyed for gasification at the adjacent "power block facility" (PBF). The outdoor storage incorporates: a truck emergency access; a storage buffer zone; a sealed pavement; curbs; and a stormwater control system (catch basins; a pump station; and underground and above ground storage tanks); 2. A "power block facility" (PBF) housing various ancillary equipment, including: a fluidized bed gasification and boiler system designed to process biomass (wood); a bottom ash residue collection system; a fly ash residue collection system; an air pollution system; an induced (ID) fan/stack system; a storage silo for bottom and fly ash residue; steam turbine generator system; a water treatment system designed to filter, clarify and store cooling water; and a transformer connected to the electrical distribution grid; and 3. An office building that houses the system control/monitoring room. 1.5 Description of Industrial Process When in operation, the Permittee operates for 24 hours a day. The facility is fueled solely by wood (biomass) and utilizes a fluidized bed gasification process with a single close-coupled boiler to power the steam turbine generator. Using a network of conveyors, biomass is fed into a bubbling-bed gasifier under tightly controlled, sub-stoichiometric oxygen conditions, to produce a high‐quality synthetic gas (“syngas”). The syngas is combusted to transfer heat to water‐filled tubes, thereby generating steam. The steam is then superheated by capturing residual thermal energy from the flue‐ gas stream before directing it into a steam turbine. The rotation of the turbine drives the on-site generator, producing renewable electricity that is sent to the power grid, which supports local as well as regional energy needs. The biomass fuel comes from various sources, which includes forest management residues, land clearing debris, and waste wood from industries and construction and demolition (C&D) waste. Bio- diesel (B100) is also used to supplement the solid fuel supply during startup, refractory curing, and for process stabilization. The following intake and discharges are associated with the electricity producing process. 1.5.1 DSN 101-1 The water withdrawn from the Quinebaug River is treated when necessary to reduce solids and then runs through a tube and shell condenser to condense the extremely pure high-pressure steam generated from the process described above. The steam is condensed back into water for reuse in the process. There is no contact between the steam and the NCCW. The NCCW goes into a three-cell cooling tower to reduce heat by evaporation and is recycled approximately five times prior to discharge to the Quinebaug River at the pump house on Packer Road in Canterbury. Each cell includes a cooling tower bypass valve and manual isolation valve that is used during extreme cold weather months to avoid freezing in the cooling tower. During normal operations all three fans are operated. The discharge is comprised of a maximum flow of 173,571 gpd of treated cooling tower blowdown wastewater. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 6 of 43 [Page 37] 1.5.2 DSN 102-1 This is an intermittent discharge of 225,000 gpd of fire suppression pump test wastewater. The discharge is generated from the required annual testing of fire suppression pumps. Water pumped from the Quinebaug River is stored in an on-site service water storage tank. During testing of the fire suppression pumps, the water is discharged by infiltration into groundwater via the underground stormwater infiltration system at the power plant. No chemicals are added to the water. 1.5.3 DSN 103-1 This is an intermittent discharge of 225,000 gpd of fire hydrant test wastewater. The discharge is generated from the required annual testing of fire hydrant pumps. Water pumped from the Quinebaug River is stored in an on-site service water storage tank. During testing of the fire hydrant pumps, the water is discharged by infiltration into groundwater via the underground stormwater infiltration system at the power plant. No chemicals are added to the water. 1.5.4 DSN 104-1 This is an intermittent discharge of 250,000 gpd of make-up supply tank drain and overflow wastewaters. City water or water pumped from the Quinebaug River is stored in an on-site service water storage tank. In the event of an overflow, or draining for maintenance, the water by infiltration into groundwater via the underground stormwater infiltration system at the power plant. In recent years, the Permittee has not discharged makeup supply tank drain. 1.5.5 Intake SN 101H The maximum intake cooling water flow is 893,000 gallons per day. Intake cooling water undergoes cylindrical wedge wire screening to minimize impingement and entrainment. Intake cooling water also undergoes neutralization, coagulation, flocculation, clarification and filtration on an as needed basis before it is used for non-contact cooling on site. The waste from the water treatment is hauled off site for disposal. 1.5.6 DSN 105-1 The demineralized water tank is now situated inside the power generating facility and overflows will discharge via floor drains to the sanitary sewer system. The discharge is covered under the “General Permit for Discharges from Miscellaneous Industrial Users (MIU GP)” and therefore has removed from the permit. 1.6 Treatment System Description DSN 101-1 – The cooling tower blowdown undergoes filtration in two in-line 55 microns filters. Post filtration, the wastewater is dechlorinated using sodium bisulfite, and pH adjusted before discharge to the Quinebaug River. The treatment system is fully automated with continuous flow, pH, ORP and temperature monitoring. The Permittee has a preventative measure built into the logic of the wastewater control system configured to close the effluent valve at 88oF and prevent it from re- opening until the measured temperature is below 88 oF. This is to ensure that the Permittee will not discharge at a temperature that is higher than the temperature limit in the permit. The temperature data is transferred to a spreadsheet during discharge events only. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 7 of 43 [Page 38] The effluent monitoring is conducted at the power plant using an automatic sampler with flow proportional capacities prior to the discharge travelling about two miles to the discharge location at the pump house via underground piping system. DSNs 102-1, 103-1 and 104-1 – There is no treatment for these wastewaters. Intake SN 101-H – The Permittee withdraws water from Quinebaug River and treats as necessary to reduce solids to meet the water quality necessary for facility production use. The treatment of the intake water prior to use at the facility includes neutralization, coagulation, flocculation, clarification, and filtration. The waste from the water treatment is hauled off site for disposal. 1.7 Facility Changes The Regulations of the Connecticut State Agencies (“Regs. Conn. State Agencies”) require that permittees notify DEEP and obtain written approval of any facility expansion or process change that may result in an increased or new discharge or constitute a new source, and of any expansion or significant changes made to a wastewater collection system, treatment system, or its method of operation in accordance with Regs. Conn. State Agencies Section 22a-430-3(i). These regulatory provisions are commonly referred to as “3(i) determinations”. DEEP will review the notification and determine if the change can be implemented under the current permit or if the requested change requires a permit modification to protect waters of the State in accordance with Regs. Conn. State Agencies Section 22a-430-4(p). The following are a list of 3(i) determinations since the previous permit: 3(i) Application Date Issued Change Implemented No. 201806852 May 23, 2018 Ability to interchange intake water treatment chemicals, ChemTreat P899L with NALCO 8136, ChemTreat P813E with NALCLEAR 7766 and interchange cooling tower treatment chemicals ChemTreat CL5688 with NALCO 3DT138, ChemTreat CL-41 with NALCO Acti-brom 1338, and ChemTreat BL-1258 with NALCO 7408. 201808200 July 27, 2018 The re-use of part of the demineralized water production system effluent as partial source water for non-contact cooling. The remaining effluent from demineralized water production system will continue to discharge to the sanitary sewer and is permitted under the miscellaneous general permit, while the portion used for NCCW will be discharged to the Quinebaug River via DSN 101-1. 201904464 April 10, 2019 Replacement of the 55 microns cooling water blowdown discharge filter elements with 25 microns, to improve filtration. 202200807 April 19, 2022 In addition to the already authorized chemicals, ability to use NCCW treatment chemicals, Klaraid IC1172, Polyfloc AS 1002, E.C.O Film EF 2503, Spectrus DT 1404 and Spectrus OX 1201, supplied by GE Suez, to provide flexibility with regards to supplier’s costs and product availability. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 8 of 43 [Page 39] 3(i) Application Date Issued Change Implemented No. 202306179 November 22, The use of BetzDearborn DCL30, Hypersperse MDC 714 and 2023 Optisperse ADJ5050 to improve the performance of the reverse osmosis system at the facility and Foamtrol AF3566 for defoaming in the cooling tower. 1.8 Compliance History 1.8.1 Discharge Monitoring Report Review Based on the Permittee’s Discharge Monitoring Reports (“DMR”), data evaluated from January 2020 to December 2024, the Permittee reported the following effluent violation, which has been corrected. Table 1.8.1: Effluent violations in the past 5 years Month/ DSN Parameter Type of Permitted Exceedence Year Limit Limit 7/30/2021 101-1 Total Suspended MDL 30 mg/l 48 mg/l Solids MDL: Maximum daily limit 1.8.2 Notice of Violation A Notice of Violation (NOV WR IN 14014) (“NOV”) was issued on June 17, 2014, for the exceedance of effluent limitations at DSN 101-1 from Jan. 2014 - Mar. 2014 (see Table 1.8.2 below). The exceedances were investigated, and corrective actions were taken to prevent future recurrence. The corrective actions taken included reduction of the pore size of inline filters from 110 to 55 microns, and implementation of periodic inspections. Table 1.8.2: DSN 101-1 NOV Effluent violations Month/ Parameter Type of Permitted Exceedence Year Limit Limit Lead AML 0.019 mg/l 0.04 mg/l Lead MDL 0.019 mg/l 0.06 mg/l 1/2014 Total suspended solids MDL 33 mg/l 30 mg/l Temperature MDL 90 oF 94 oF Aluminum, total AML 1.42 mg/l 1.51mg/l Lead AML 0.019 mg/l 0.06 mg/l Lead MDL 0.019 mg/l 0.06 mg/l 2/2014 Total suspended solids AML 40.5 mg/l 20 mg/l Total suspended solids MDL 114 mg/l 30 mg/l Aluminum, total MDL 3.11 mg/l 2.86mg/l Lead AML 0.019 mg/l 0.03 mg/l 3/2014 Lead MDL 0.019 mg/l 0.05 mg/l Total suspended solids AML 28 mg/l 20 mg/l Total suspended solids MDL 65 mg/l 30 mg/l Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 9 of 43 [Page 40] For the temperature exceedance, the high temperature reported was not an actual exceedance because, as reported by the permittee the discharge valve was closed, and the Permittee was not discharging at that time. Rather, it was a false reading due to the temperature sensor location. The control system is now configured to close the discharge valve at 88oF and prevent it from re-opening until the measured temperature is below 88 oF. The NOV was closed on July 10, 2015. 1.8.3 Previous NPDES Permit Compliance Schedule The previous permit issued on August 30, 2013, contained a compliance schedule that required the Permittee to submit a complete Attachment O (Part B discharge analysis of the permit application). The Permittee submitted the required Attachment O with the permit renewal application submitted on February 28, 2018. The compliance schedule in the previous permit also required the Permittee to submit for the Commissioner’s review and written approval, a scope of study and schedule for (1) performing seasonal thermal field monitoring verification of its discharge into the Quinebaug River, (2) a one- year impingement study, and (3) a two-year entrainment monitoring and evaluation of the cooling water intake structure. The studies were to be performed when the Commissioner provided written notification to the Permittee that anadromous fish population were restored in the Quinebaug River, upstream of the Aspinook Pond. The Permittee submitted “Scopes of Study for Impingement and Entrainment Monitoring and Thermal Field Monitoring” dated February 18, 2014. The Permittee proposed not to conduct an impingement study because of the following reasons. 1. The design through screen velocity of 0.25 feet per second (“fps”) should preclude the impingement of nearly all organisms with even rudimentary swimming abilities; 2. There is no practical method to collect quantitative impingement data, based on the intake structure’s passive design; and 3. Previous evaluations indicate that impingement is exceedingly rare on this type of screen. The U.S. Environmental Protection Agency (“EPA”) has determined that a through screen velocity of 0.5 fps adequately reduces impingement; therefore, CT DEEP accepts the Permittee’s request and is no longer requiring the impingement study (EPA. 2014. Technical Development Document for the Final Section 316(b) Existing Facilities Rule (EPA-821-R-14-002). pp 8-3). The impingement, entrainment, and thermal verification studies were not completed because the Permittee did not receive DEEP approval of the scope of studies in advance of this permit renewal. As part of this renewal, DEEP is no longer requesting an impingement and entrainment study because of the 316(b) final rule promulgation on August 15, 2014, which shows that closed-cycle recirculating system adequately addresses entrainment (see Section 3.16 of this fact sheet). The thermal verification study will be conducted under the renewed permit and has been included as a compliance schedule. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 10 of 43 [Page 41] 1.9 General Issues Related to the Application 1.9.1 Federally Recognized Indian Land As provided in the permit application, the site is not located on federally-recognized Indian land. 1.9.2 Coastal Area/Coastal Boundary The activity is not located within a coastal boundary as defined in Conn. Gen. Stat. 22a-94(b). 1.9.3 Endangered Species There are state listed species documented within the proposed discharges areas according to the June 2025 State and Federal Listed Species and Natural Communities Map. However, the discharges are not anticipated to have adverse impact to state listed species. 1.9.4 Aquifer Protection Areas As provided in the permit application, the site is not located within a protected area identified on a Level A or B map. 1.9.5 Conservation or Preservation Restriction As provided in the permit application, the property is subject to a conservation or preservation restriction. The Permittee implements invasive plant management and monitoring on conservation easements to mitigate impact to state listed species and submits an annual report to the Natural Diversity Data Base. 1.9.6 Public Water Supply Watershed As provided in the permit application, the site is not located within a public water supply watershed. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 11 of 43 [Page 42] Section 2 Receiving Water Body Information The receiving waterbody, Quinebaug River, is identified as CT3700-00_02. The Segment of the Quinebaug River is an un-impaired class “B” water. FINAL-2022-IWQR-Connecticut-305b- Assessment-Results-for-Rivers-and-Streams.pdf Figure 2.1. Image of Applicable Section of 2022 Connecticut Integrated Water Quality Report 2.1 Designated Uses The designated uses for Class B waters as defined in the Regulations of Connecticut State Agencies Regs. Conn. State Agencies 22a-426-4(h) are: 1) habitat for fish other aquatic life and wildlife; 2) recreation; 3) harvesting; and 4) industrial and agricultural water supply. 2.2 Applicable Total Maximum Daily Load (“TMDL”) “A Total Maximum Daily Load Analysis to Achieve Water Quality Standards for Dissolved Oxygen in Long Island Sound” (December 2000) (Long Island Sound TMDL) applies to this segment of the Quinebaug River. This TMDL is based on the control of total nitrogen. The Permittee’s discharge has not been assigned a waste load allocation for nitrogen as part of this TMDL. Therefore, nitrogen monitoring requirements without numeric limitations have been included in the permit. 2.2.1 Phosphorus DEEP developed a final report, “Recommendations for Phosphorus Strategy Pursuant to PA 12-155” (February 16, 2017) (Phosphorus Strategy PA12-155), for freshwater in 2017. The Phosphorus Strategy applies to the Quinebaug River. The Permittee’s discharge did not exist at the time the Phosphorus Strategy was developed; therefore, the current permit prohibited the discharge of phosphorus. Specifically, the permit prohibits the Permittee from using any chemicals that contain phosphorus in any process or activity that may result in a discharge to waters of the state. The Quinebaug River has been identified as a priority water and is listed on the 2022-2024 priority list of waters for action plan development for phosphorus. The action plan titled “Connecticut Advance Restoration Plan For Total Phosphorus in Non-Tidal Surface Waters” (Connecticut Advance Restoration Plan for Total Phosphorus in Non-Tidal Waters) was approved on September 19, 2024. The plan carried forward the conditions that pertain to Quinebaug River in the Phosphorus Strategy PA12-155. Therefore, the prohibition of the use of phosphorus in any process or activity that may result in a discharge to the waters of the state is being carried forward in the permit renewal. Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 12 of 43 [Page 43] Figure 2.2. Images of discharge locations 114 Packer Road, Canterbury, CT 06331: Intake and discharge to Quinebaug River 12 Mill Brook Road, Plainfield, CT 06374: Infiltration to groundwater Draft NPDES Permit No. CT0030473 Draft Fact Sheet December 2025 Page 13 of 43 [Page 44] portal.ct.gov/DEEP Figure 2.3. Applicable Section of 2022 Integrated Water Quality Report (“IWQR”) Waterbodies with Impairments 2022-2024 IWQR Priority List of Waters for Action Plan Development (including TMDL development) Plan Name Waterbody Waterbody Cause Plan Type Status ID ID Interim CT3700- Quinebaug Phosphorus, total Alternative Approved Phosphorus 00_02 River -02 Restoration September Strategy Approach 19, 2024 final-2022-iwqr-appendix-c-1-priority-list-for-action-plan-development-2022-2024.pdf A review of the discharge monitoring data from 1/1/2020 – 12/31/2024 showed that 2,300 µg/l of phosphorus was discharged on 11/30/2021, 2,900 µg/l was discharged on 3/31/2023, and an average daily concentration of 382 µg/l of phosphorus was discharged within the five-year period. The effluent phosphorus is likely associated with the facility’s intake water. The Permittee has reviewed the cooling tower chemicals used on site and certified that none contain phosphorus. Draft NPDES Permit No. CT0030473 Draft Fact sheet December 2025 Page 14 of 43 [Page 45] Section 3 Permit Conditions and Effluent Limitations 3.1 Basis for Limits Technology and water-quality based requirements are considered when developing permit limits. Technology-based effluent limits (“TBELs”) represent the minimum level of control imposed under the Clean Water Act (“CWA”). Industry-specific technology-based limits are set forth in 40 CFR Sections 405 – 471 (EPA’s Effluent Limitation Guidelines) and in Regs. Conn. State Agencies Section 22a-430-4(s)(2). Water quality-based limits are designed to protect water quality and are determined using the procedures set forth in EPA’s Technical Support Document for Water Quality- Based Toxics Control, 1991 (“TSD”). When both technology and water quality-based limits apply to a particular pollutant, the more stringent limit would apply. In addition, water quality-based limits are required when any pollutant or pollutant parameter (conventional, non-conventional, toxic, and whole effluent toxicity) is or may be discharged at a level that causes, has reasonable potential to cause, or contributes to an excursion above any water quality criteria. Numeric water quality criteria are found in Regs. Conn. State Agencies Section 22a-429-9 of the Connecticut Water Quality Standards (“WQS”). 3.2 Pollutants of Concern The following pollutants are included as monitoring pollutants in the permit for DSN 101-1 for the reasons noted below: Reason for Inclusion Pollutant Pollutant with a Pollutant Identified Pollutant Otherwise Waste Load as Present in the Expected to be Allocation from a Effluent Through Present in the TMDL Sampling Effluent Aluminum ✓ Ammonia ✓ Boron ✓ Chlorine, Total Residual ✓ Chromium, Total ✓ Copper, Total ✓ Iron, Total ✓ Lead ✓ Kjeldahl Nitrogen, Total ✓ (as N) Nitrate (as N) ✓ Nitrite (as N) ✓ Nitrogen, Total ✓ Phosphorus, Total ✓ Temperature ✓ Total Suspended Solids ✓ Zinc ✓ 126 Priority pollutants ✓ except chromium and zinc Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 15 of 43 December 2025 [Page 46] Reason for Inclusion Pollutant Pollutant with a Pollutant Identified Pollutant Otherwise Waste Load as Present in the Expected to be Allocation from a Effluent Through Present in the TMDL Sampling Effluent Acute and chronic toxicity monitoring requirements are also included in the permit consistent with Section 22a-430-3(j)(3) of the Regs. Conn. State Agencies. pH monitoring was included in the permit consistent with Section 22a-426-9(a)(1). The following pollutants are included as monitoring pollutants in the permit for DSN 102-1 for the reasons noted below: Reason for Inclusion Pollutant Pollutant with a Pollutant with a Pollutant with a Waste Load Waste Load Waste Load Allocation from a Allocation from a Allocation from a TMDL TMDL TMDL Aluminum ✓ Boron ✓ Copper, Total ✓ Iron, Total ✓ Lead ✓ Phosphorus, Total ✓ Zinc ✓ pH monitoring is included in the permit. The following pollutants are included as monitoring pollutants in the permit for DSN 103-1 for the reasons noted below: Reason for Inclusion Pollutant Pollutant with a Pollutant with a Pollutant with a Waste Load Waste Load Waste Load Allocation from a Allocation from a Allocation from a TMDL TMDL TMDL Aluminum ✓ Boron ✓ Copper, Total ✓ Iron, Total ✓ Lead ✓ Phosphorus, Total ✓ Zinc ✓ pH monitoring is included in the permit. The following pollutants are included as monitoring pollutants in the permit for DSN 104-1 for the reasons noted below: Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 16 of 43 December 2025 [Page 47] Reason for Inclusion Pollutant Pollutant with a Pollutant with a Pollutant with a Waste Load Waste Load Waste Load Allocation from a Allocation from a Allocation from a TMDL TMDL TMDL Aluminum ✓ Boron ✓ Copper, Total ✓ Iron, Total ✓ Lead ✓ Phosphorus, Total ✓ Zinc ✓ pH monitoring is included in the permit. 3.2.1 Priority Pollutant Monitoring While the facility does not fall within the Steam Electric Power Generating Point Source Category because it uses biomass for its fuel source rather than a fossil or nuclear fuel, it meets the other criteria for classification under this industrial category. The cooling tower maintenance and operation at the facility is similar to that of fossil fuel power plants cooling towers. Therefore, a monitoring requirement for chromium and 126 priority pollutants limits, once during the term of the permit, was added the permit. 3.3 Technology Based Effluent Guidelines Technology-based treatment requirements represent the minimum level of control that must be imposed under CWA § 301(b) and 402 to meet best practicable control technology currently available (“BPT”) for conventional pollutants and some metals, best conventional control technology (“BCT”) for conventional pollutants, and best available technology economically achievable ( “BAT”) for toxic and non-conventional pollutants. See 40 CFR § 125 Subpart A and Regs. Conn. State Agencies Section 22a-430-4(l)(4)(A). Subpart A of 40 CFR § 125 establishes criteria and standards for the imposition of technology-based treatment requirements in permits under § 301(b) of the CWA, including the application of EPA promulgated Effluent Limitation Guidelines (“ELGs”) and case-by-case determinations of effluent limitations under CWA § 402(a)(1). EPA promulgates New Source Performance Standards ( “NSPS”) under CWA § 306 and 40 CFR § 401.12. See also 40 CFR § 122.2 (definition of “new source”) and 122.29. The Steam Electric Power Generating Point Source Category at 40 CFR § 423 was reviewed to determine its applicability to the facility’s discharges. This regulation is applicable to wastewater discharges from the operation of a generating unit by an establishment whose generation of electricity is the predominant source of revenue or principal reason for operation, and whose generation of electricity results primarily from a process utilizing fossil-type fuel (coal, oil, or gas), fuel derived from fossil fuel (e.g., petroleum coke, synthesis gas), or nuclear fuel in conjunction with a thermal cycle employing the steam water system as the thermodynamic medium. The Permittee derives its Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 17 of 43 December 2025 [Page 48] fuel from synthesis gas from wood biomass. Therefore, 40 CFR § 423 is not applicable to the facility’s discharges. In the absence of published technology-based effluent guidelines, the permit writer is authorized under CWA § 402(a)(1)(B) and Regs. Conn. State Agencies Section 22a-430-4(m) to establish effluent limitations on a case-by-case basis using best professional judgment (“BPJ”). 3.4 Zone of Influence A zone of influence (“ZOI”) of 137,760 gallons per hour was determined on November 29, 2007, during the processing of the previous permit (see Appendix A). The previously assigned ZOI of 137,760 gallons per hour is carried forward. 3.5 Reasonable Potential Analysis Pursuant to CWA Section 301(b)(1)(C) and 40 CFR Section 122.44(d)(1), NPDES permits must contain any requirements in addition to TBELs that are necessary to achieve water quality standards established under Section 303 of the CWA. See also 33 United States Code (USC) Section 1311(b)(1)(C). In addition, limitations “must control any pollutant or pollutant parameter (conventional, non-conventional, or toxic) which the permitting authority determines are or may be discharged at a level which will cause, have the reasonable potential to cause, or contribute to an excursion above any water quality standard, including State narrative criteria for water quality.” 40 CFR Section 122.44(d)(1)(i). To determine if the discharge causes, or has the reasonable potential to cause, or contribute to an excursion above any WQS, EPA considers: 1) existing controls on point and non-point sources of pollution; 2) the variability of the pollutant or pollutant parameter in the effluent; 3) the sensitivity of the species to toxicity testing (when evaluating whole effluent toxicity); and 4) where appropriate, the dilution of the effluent by the receiving water. See 40 CFR Section 122.44(d)(1)(ii). If the permitting authority determines that the discharge of a pollutant will cause, has the reasonable potential to cause, or contribute to an excursion above WQSs, the permit must contain Water Quality Based Effluent Limits (“WQBELs”) or require addition al monitoring if there is insufficient data to develop a WQBEL, for that pollutant. See 40 CFR Section 122.44(d)(1)(i). The reasonable potential analysis was conducted using procedures consistent with EPA’s TSD. For each pollutant of concern, DEEP determines t he project maximum concentration (“PMC”) of the pollutant in the receiving stream and compares it to the applicable flow adjusted water quality criteria (“WQC”). When the PMC is lower than the flow adjusted WQC, there is no potential for the discharge to exceed the WQC. When the PMC is higher than the flow adjusted WQC, there is a potential for the discharge to exceed the WQC (and permit limits are needed). In the reasonable potential analysis, the PMC is calculated by multiplying maximum reported concentration with a statistical multiplier. The statistical multiplier is determined using the equation C99 = exp(2.326σ - 0.5σ2), where σ2 = ln (Cv2 + 1) or from Table 3-1 of the TSD for 20 data set or less. The reasonable potential analysis indicates that limits are required for aluminum, chlorine, copper, and lead. The reasonable potential analysis results are included in Sections B2 and B4 of Appendix B. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 18 of 43 December 2025 [Page 49] 3.6 Whole Effluent Toxicity The Permittee shall comply with effluent standards or prohibitions established by CWA Section 307(a) and Regs. Conn. State Agencies Section 22a-430-4(l) and may not discharge toxic pollutants in concentrations or combinations that are harmful to humans, animals, or aquatic life. If toxicity is suspected in the effluent, DEEP may require the Permittee to perform acute or chronic whole effluent toxicity testing. The Permittee’s previous permit required quarterly acute toxicity testing using Daphnia Pulex and Pimephales promelas and annual chronic toxicity testing using Ceriodaphnia dubia and Pimephales promelas. The previous permit had a no observable acute effect level (“NOAEL”) limit of 90% or greater survival in an undiluted effluent, consistent with Regs. Conn. State Agencies 22a-430- 4(l)(5)(A). During the last permit cycle, the Permittee had no exceedances of its NOAEL acute toxicity limit. The review of DMR data (January 2020 – December 2024) for acute toxicity tests, showed a range of 98% - 100% survival of test organisms in an undiluted effluent which shows the discharge is not toxic. A review of the Permittee’s chronic toxicity testing results also showed that the discharge was not chronically toxic, because the 48-hour LC50 (lethal concentration 50), 7-Day LC50, 7-Day C-NOEC (no observed effect concentration), 7-Day C-LOEC (lowest observed effect concentration), 7-Day IC25 (inhibition concentration 25) were 100% in all tests conducted during the period of January 2020 and December 2024. A reasonable potential analysis was not performed on toxicity because toxicity was not demonstrated beyond acute permit limits or in chronic tests. Consistent with Regs. Conn. State Agencies 22a-430- 4(l)(5)(A), the acute toxicity limit is maintained in the permit. 3.7 Water Quality Based Effluent Limitations (“WQBELS”) The CWA and federal regulations require that effluent limitations based on water quality considerations be established for point source discharges when such limitations are necessary to meet state or federal water quality standards that are applicable to the designated receiving water. This is necessary when less stringent TBELs would interfere with the attainment or maintenance of water quality criteria in the receiving water. See CWA Section 301(b)(1)(C) and 40 CFR Section 122.44(d)(1),122.44(d)(5), 125.84(e) and 125.94(i). WQBELs were established by DEEP for pollutants that demonstrated the reasonable potential to cause or contribute to an excursion above any water quality standard using the methodology in EPA’s TSD. Wasteload allocations (“WLA”) based on applicable WQC are calculated using a mass balance equation. Long-term averages (“LTA”) are calculated by multiplying the WLA by a 99th percentile statistical factor, as shown below: (0.5σ2−zσ) (0.5σ2−zσ ) LTAacute = WLAacute X e and LTAchronic = WLAchronic X e 4 4 Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 19 of 43 December 2025 [Page 50] To be protective of the most sensitive beneficial use, the most limiting of the acute, chronic or health LTA is selected and used for the effluent limits calculation. (zσ − 0.5σ2) (zσ− 0.5σ2) AML = LTA X e n n and MDL = LTA X e Where σ2 = ln(CV2 + 1) , Z = 1.645 for 95th percentile probability basis, and Z = 2.326 for 99th percentile probability basis and n = number of samples per month, for sampling frequency that is less than 4 times a month, use n = 4. The calculated WQBELs are in Section B-3 of Appendix B. 3.8 Comparison of Limits After preparing and evaluating applicable TBELs and WQBELs, the most stringent limits are applied in the permit. Pollutants of concern that only require monitoring without limits are not included in the below table. Table 3.8.1: Comparison of Limits Based on Different Criteria Water Quality Regs. Conn. Limits Based State Previous permit Case by case Parameters on EPA/505/2- Agencies limits determination 90-001 22a-430- 4(l)(5)(A) Acute Aquatic NOAEL > toxicity, Daphnia --- 90% NOAEL > 90% --- pulex Acute Aquatic toxicity, --- NOAEL > NOAEL > 90% --- Pimephales 90% promelas AML = 1.420 mg/l AML = 1.768 mg/l MDL = 2.860 mg/l Aluminum, total MDL = 4.075 mg/l --- MIL = 4.290 mg/l --- Mass AML = 0.68 kg/d Mass MDL = 1.36 kg/d Total Residual AML = 0.139 mg/l AML = 0.180 mg/l Chlorine MDL = 0.331 mg/l --- MDL = 0.360 mg/l MIL = 0.497 mg/l MIL = 0.540 mg/l AML = 0.096 mg/l AML = 0.253 mg/l MDL = 0.190 mg/l Copper, total MDL = 0.632 mg/l --- MIL = 0.280 mg/l --- Mass AML = 0.046 kg/d Mass MDL = 0.091 kg/d AML = 0.019 mg/l AML = 0.026 mg/l MDL = 0.039 mg/l Lead, total MDL = 0.055 mg/l --- MIL = 0.058 mg/l --- Mass AML = 0.68 kg/d Mass MDL = 1.36 kg/d Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 20 of 43 December 2025 [Page 51] Table 3.8.1: Comparison of Limits Based on Different Criteria Water Quality Regs. Conn. Limits Based State Previous permit Case by case Parameters on EPA/505/2- Agencies limits determination 90-001 22a-430- 4(l)(5)(A) pH, minimum 6.5 S.U. --- 6.0 S.U. --- pH, maximum 8.0 S.U. --- 9.0 S.U. --- Temperature --- 90oF Total Suspended AML = 20.0 mg/l AML = 20.0 mg/l Solids --- --- MDL = 30.0 mg/l MDL = 30.0 mg/l MIL = 45.0 mg/l MIL = 45.0 mg/l AML = 0.640 mg/l Zinc, total --- --- MDL = 1.300 mg/l --- MIL = 1.950 mg/l Note: The highlighted numbers represent the most stringent effluent limits. AML: Average Monthly Limit, MDL: Maximum Daily Limit and MIL: Maximum Instantaneous Limit, Mass limits in kg/d = concentration limits (mg/l) X 0.126103 X 106 X 3.785 liter/d The MIL for total residual chlorine is calculated by multiplying the MDL by a factor 1.5, consistent with Regs. Conn. State Agencies Section 22a-430-4(s). 3.9 Sampling Frequency, Type, and Reporting The permit proposes quarterly acute toxicity consistent with Regs. Conn. State Agencies Section 22a- 430-3(j). The permit also proposes sampling for chronic toxicity and 126 priority pollutants except chromium and zinc, and weekly sampling for other parameters based on case -by-case determination using best professional judgement. The proposed sample types are consistent with Regs. Conn. State Agencies Section 22a-430-4(c)(20). 3.10 Effluent Limitations and Monitoring Requirements Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency DSN 101-1: Acute Aquatic > 90% Survival Regs. Conn. Daily Toxicity, State Agencies Composite Daphnia pulex, 22a-430- NOAEL = 100% 4(l)(5)(A) Quarterly Anti- backsliding regulations Acute Aquatic > 90% Survival Regs. Conn. Quarterly Toxicity State Agencies Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 21 of 43 December 2025 [Page 52] Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency Pimephales 22a-430- promelas, 4(l)(5)(A) NOAEL = 100% Anti- backsliding regulations Chronic Aquatic Toxicity (Survival) Monitoring only requirement for Annually Ceriodaphnia pollutant of concern dubia Chronic Aquatic Toxicity Monitoring only requirement for (Reproduction) pollutant of concern Annually Ceriodaphnia dubia Chronic Aquatic Toxicity (Survival) Monitoring only requirement for Annually Pimephales pollutant of concern promelas Chronic Aquatic Toxicity Monitoring only requirement for (Growth) pollutant of concern Annually Pimephales promelas AML = 1.48 mg/l Anti- MDL = 2.86 mg/l backsliding Aluminum, Total MIL = 4.29 mg/l regulations (the Weekly previous permit limits are WQBELs) AML = 0.68 kg/d Conversion of Aluminum, Total MDL = 1.36 kg/d WQBELs to Weekly mass limits Ammonia (as N) Monitoring only requirement for Weekly pollutant of concern Boron Monitoring only requirement for Weekly pollutant of concern Chlorine, Total AML = 0.139 mg/l Grab sample Residual MDL = 0.331 mg/l WQBELs Weekly Average MIL = 0.497 mg/l Chromium, Total Monitoring only requirement for Weekly Daily pollutant of concern Composite Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 22 of 43 December 2025 [Page 53] Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency Copper, Total AML = 0.096 mg/l Anti- MDL = 1.90 mg/l backsliding MIL = 2.88 mg/l regulations (the Weekly previous permit limits are WQBELs) AML = 0.046 kg/d Conversion of Copper, Total MDL = 0.091 kg/d WQBELs to Weekly mass limits Flow Rate (Average 126,103 gpd Permitted Continuous Total Daily Daily) discharge flow Flow per application Flow, Maximum 173,571 gpd Permitted during 24-hr period discharge flow Continuous per application Iron, Total Monitoring only requirement for Weekly Daily pollutant of concern Composite Kjeldahl Nitrogen, Monitoring only requirement due to Weekly Total (as N) TMDL Lead, Total AML = 0.019 mg/l Anti- MDL = 0.039 mg/l backsliding MIL = 0.058 mg/l regulations (the Weekly previous permit limits are WQBELs) AML = 0.009 kg/d Conversion of Lead, Total MDL = 0.019 kg/d WQBELs to Weekly mass limits Nitrate (as N) Monitoring only requirement due to Weekly TMDL Nitrite (as N) Monitoring only requirement due to Weekly TMDL Nitrogen, Total Monitoring only requirement due to Weekly TMDL pH, Minimum 6.0 WQC Continuous Continuous (Interim) pH, Maximum 9.0 WQC (Interim) pH, Minimum 6.5 WQC Continuous (Final) Continuous pH, Maximum 8.0 WQC (Final) Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 23 of 43 December 2025 [Page 54] Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency Phosphorus, Total Monitoring only requirement due to Weekly Daily Phosphorus Strategy Composite Temperature, 90oF Anti- Instantaneous Maximum backsliding regulations (the Continuous previous permit limits are WQBELs) Temperature, Monitoring only requirement due to Calculated intake/outlet Regs. Conn. State Agencies 22a-426- Continuous differential 9(a)(1) Total Suspended AML = 20 mg/l Anti- Daily Solids MDL = 30 mg/l backsliding Weekly Composite MIL = 45 mg/l regulations Zinc, total AML = 0.64 mg/l Anti- MDL = 1.30 mg/l backsliding MIL = 1.95 mg/l regulations (the Weekly previous permit limits are WQBELs) 126 Priority Monitoring only requirement for Grab Pollutants pollutant of concern (resulting from chemical additives Once during the for cooling tower permit term maintenance) except chromium and zinc DSN 102-1: Aluminum, Total Monitoring only requirement for Annually Grab pollutant of concern Boron Monitoring only requirement for Annually pollutant of concern Copper, Total Monitoring only requirement for Annually pollutant of concern Flow, Maximum 225,000 gpd Permitted Total Daily during 24-hr period discharge flow Annually Flow per application Iron, Total Monitoring only requirement for Annually Grab pollutant of concern Lead, Total Monitoring only requirement for Annually pollutant of concern Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 24 of 43 December 2025 [Page 55] Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency pH 6.0 – 9.0 Anti- backsliding Annually regulations Phosphorus, Total Monitoring only requirement for Annually pollutant of concern Zinc, Total Monitoring only requirement for Annually pollutant of concern DSN 103-1: Aluminum, Total Monitoring only requirement for Annually Grab pollutant of concern Boron Monitoring only requirement for Annually pollutant of concern Copper, Total Monitoring only requirement for Annually pollutant of concern Flow, Maximum 225,000 gpd Permitted Total Daily during 24-hr period discharge flow Annually Flow per application Iron, Total Monitoring only requirement for Annually Grab pollutant of concern Lead, Total Monitoring only requirement for Annually pollutant of concern pH 6.0 – 9.0 Anti- backsliding Annually regulations Phosphorus, Total Monitoring only requirement for Annually pollutant of concern Zinc, Total Monitoring only requirement for Annually pollutant of concern DSN 104-1: Aluminum, Total Monitoring only requirement for Annually Grab pollutant of concern Boron Monitoring only requirement for Annually pollutant of concern Copper, Total Monitoring only requirement for Annually pollutant of concern Flow, Maximum 250,000 gpd Permitted Total Daily during 24-hr period discharge flow Annually Flow per application Iron, Total Monitoring only requirement for Annually Grab pollutant of concern Lead, Total Monitoring only requirement for Annually pollutant of concern Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 25 of 43 December 2025 [Page 56] Table 3.10.1: Effluent Limitations and Monitoring Requirements Basis for Monitoring Sample Pollutants Limit Limit /Reporting Type Frequency pH 6.0 – 9.0 Anti- backsliding Annually regulations Phosphorus, Total Monitoring only requirement for Annually pollutant of concern Zinc, Total Monitoring only requirement for Annually pollutant of concern Intake SN101H: Aluminum, Total Intake monitoring Monthly Grab Boron Monthly Copper, Total Monthly Flow Rate (Average Total daily flow Total daily Daily) flow Flow, Maximum 893,000 gpd Permitted during 24-hr period discharge flow Total daily flow per application Iron, Total Intake monitoring Monthly Grab Lead, Total Monthly pH, Minimum Monthly Instantaneous pH, Maximum Monthly Phosphorus, Total Monthly Grab Temperature Monthly Instantaneous Zinc, Total Monthly Grab AML: Average Monthly Limit MDL: Maximum Daily Limit MIL: Maximum Instantaneous Limit BPJ: Best Professional Judgment RP: Reasonable Potential WQC: Water Quality Criteria WQBELs: Water Quality Based Effluent Limits 3.10.1 Sufficiently Sensitive Methods EPA at 40 CFR 122.21(e)(3) and 40 CFR 122.44(i) requires sufficiently sensitive test methods to be utilized for all parameters in a NPDES permit. A method approved under 40 CFR 136 or required through other regulations is sufficiently sensitive when: • The method minimum level (“ML”) is at or below the level of the applicable water quality criterion or effluent limitation (if below the water quality criterion), whichever is more stringent, for the measured pollutant or pollutant parameter; or • The method ML is above the applicable water quality criterion, but the amount of the pollutant or pollutant parameter in a facility's discharge is high enough that the method detects and quantifies the level of the pollutant or pollutant parameter in the discharge; or Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 26 of 43 December 2025 [Page 57] • The method has the lowest ML of the analytical methods approved under 40 CFR part 136 or required under 40 CFR chapter I, subchapter N (effluent limit guidelines) or O (sewage sludge) for the measured pollutant or pollutant parameter. Note some effluent limit guidelines (ELGs) will specify a required ML for certain analyses. DEEP has specified ML requirements in the permit to ensure compliance with the sufficiently sensitive test method regulations. The MLs listed in the NPDES permit are the minimum concentration at which quantification must be achieved and verified during the laboratory analysis of the parameter. These values are not necessarily equivalent to the MLs that would be formally established by a lab under the ML definition at 40 CFR 136. In other words, at a minimum, the permittee’s analytical method must achieve the ML listed in the permit. This may vary from the actual ML established by the lab for the analysis, using the MDL, lowest calibration point, or other acceptable method under 40 CFR 136. 3.11 Other Permit Conditions • The permit prohibits the discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid under Section 4 of the permit. • The permit prohibits the use of any chemicals that contain phosphorus in any process or activity that may result in a discharge to the waters of the state under Section 4 of the permit (see Section 2.2.1 of this fact sheet). • The permit requires the Permittee to operate and maintain the outdoor wood storage area in accordance with “Section A.4 Stormwater Management – Outdoor Wood Storage Area” of the response to comment report dated February 19, 2008. 3.12 Compliance Schedule The permit has a compliance schedule that follows the requirements found under 40 CFR Section 122.47 and RSCA Section 22a-430-4(l)(3). • The Permittee is required to perform a thermal verification study, see Section 3.16 of this fact sheet. • The previous permit pH limits were changed from 6.0 – 9.0 S.U. to 6.5 – 8.0 S.U. consistent with the water quality criteria for a class “B” waterbody. A review of discharge monitoring data shows the Permittee may not be able to immediately comply with the proposed limits. As such, this permit contains a compliance schedule requiring the Permittee to evaluate alternate actions to achieve compliance with the proposed pH limits. 3.13 Antidegradation Implementation of the Antidegradation Policy follows a tiered approach pursuant to the federal regulations (40 CFR Section 131.12) and consistent with the Connecticut Antidegradation Policy included in the Connecticut Water Quality Standards (Section 22a-426-8(b-f) of the Regulations of Connecticut State Agencies). Tier 1 Antidegradation review applies to all existing permitted discharge activities to all waters of the state. Tiers 1 and 2 Antidegradation reviews apply to new or increased discharges to high quality waters and wetlands, while Tiers 1 and 3 Antidegradation reviews apply to new or increased discharges to outstanding national resource waters. This discharge is an existing discharge, and the Permittee does not propose an increase in volume or concentration of constituents. Therefore, only the Tier 1 Antidegradation Evaluation and Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 27 of 43 December 2025 [Page 58] Implementation Review was conducted to ensure that existing and designated uses of surface waters and the water quality necessary for their protection are maintained and preserved, consistent with Connecticut Water Quality Standards, Regs. Conn. State Agencies Sec.22a-426-8(a)(1). This review involved: • An evaluation of narrative and numeric water quality standards, criteria and associated policies; • The discharge activity both independently and in the context of other dischargers in the affected waterbodies; and • Consideration of any impairment listed pursuant to Section 303d of the federal Clean Water Act or any TMDL established for the waterbody. DEEP has determined that the discharges or activities are consistent with the maintenance, restoration, and protection of existing and designated uses assigned to the receiving water body by considering all relevant data. Compliance with all the terms and conditions in the new permit would ensure that existing and designated uses of surface waters and the water quality necessary for their protection are maintained and preserved. 3.14 Anti-Backsliding This permit has effluent limitations, standards or conditions that are at least as stringent as the final effluent limitations, standards, or conditions in the previous permit as required in 40 CFR Section 122.44(l) and Regs. Conn. State Agencies Section 22a-430-4(l)(4)(A)(xxiii). 3.15 Categorical Discharge Conditions Consistent with 40 CFR § 423.15, the permit prohibits the discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fluid under Section 4.5 of the permit. 3.16 Cooling Water Intake Structure Section 316(b) Section 316(b) of the Federal Water Pollution Control Act, U.S.C. Section 1326(b) states that “any standard established pursuant to Section 301 or 306 of this Act and applicable to a point source shall require that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available (“BTA”) for minimizing adverse environmental impact”. The federal regulations establish requirements under Section 316(b) of the CWA for existing power generating facilities and existing manufacturing and industrial facilities with a cooling water intake structure having a design intake flow greater than two million gallons per day of water from waters of the United States and use at least 25 percent of the water they withdraw exclusively for cooling purposes. 40 CFR 125.92 defines “Cooling water intake structure” as “the total physical structure and any associated constructed waterways used to withdraw cooling water from waters of the United States. The cooling water intake structure extends from the point at which water is first withdrawn from waters of the United States up to and including the intake pumps.” The August 15, 2014, 316(b) final rule was promulgated which applies to existing facilities that withdraw more than two MGD of water and use at least 25% of the actual intake flow exclusively for cooling purposes. However, 40 CFR 125.90(b), states “Cooling water intake structures not subject to requirements under parts 125.94 through 125.99 or subparts I or N of this part must meet requirements Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 28 of 43 December 2025 [Page 59] under Section 316(b) of the CWA established by the Director on a case-by-case, best professional judgment (“BPJ”) basis.” 3.16.1 Cooling Water Intake Structure (“CWIS”) Description The Permittee’s intake is identified as DSN 001-H in the permit. The Permittee has a water diversion permit associated with the intake and is authorized to withdraw 893,000 gpd from the Quinebaug River. The intake structure is located on 114 Packer Road, Canterbury, about two miles from the power plant. The water withdrawn for non-contact cooling is recycled about five times using a cooling tower before it is discharged back into the Quinebaug River. The cooling tower removes heat from the hot water by evaporation and recycles the cooler water. The intake is comprised of two pumps with maximum capacities of 1,320 gallons per minute (“gpm”) but set to operate 200 - 750 gpm. The facility operates the pumps almost continuously during plant operation, which is 24 hours per day. The intake is also comprised of a horizontal intake pipe with a single cylindrical wedge-wire screen. The cylindrical wedge-wire screen is located near the river bottom approximately 100 feet from the riverbank. The Johnson Model T-12 HCE cylindrical wedge- wire screen is 12 inches in diameter and 38 inches long. It has a slot opening size of 0.125 inches (3.2 mm) and a design through screen velocity of 0.25 fps. The screen is equipped with an air burst system to clear the screen of accumulated debris. Additionally, the CWIS is equipped with a water backflushing system which uses a reserve tank of raw river water to backflush the screen as an alternative to the air burst system. 3.17.2 Best Technology Available (“BTA”) Determination on CWIS Since the Permittee withdraws less than two MGD, DEEP has made a case -by-case BPJ determination consistent with 40 CFR 125.90(b), as follows: Impingement mortality: The Permittee’s intake has a design intake through-screen velocity below 0.5 fps. This is an acceptable means for existing units to comply with the BTA standards for impingement mortality as defined by 40 CFR 125.94(c)(2). In addition, the Permittee operates a cooling tower, which is considered a closed-cycle recirculating system as defined by 40 CFR 125.83. To supplement this, the permit requires actual intake flows to be measured daily from DSN 001-H. The monitoring is representative of normal operating conditions, and includes measuring cooling water withdrawals, make -up water, and blowdown volume. This technology also meets BTA for impingement mortality for existing units consistent with 40 CFR 125.94(c)(2), and new units consistent with 40 CFR 125.94(e). DEEP has determined that consistency with the federal regulations for existing and new units is an acceptable means for meeting BTA standards to reduce impingement mortality. Entrainment: As discussed above, the Permittee employs a closed-cycle recirculating system. This technology satisfies the BTA standards for entrainment for new units at existing facilities as defined by 40 CFR 125.94(e). Consistency with the federal regulations for new units is an acceptab le means for meeting BTA standards for impingement. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 29 of 43 December 2025 [Page 60] 3.18 Variances and Waivers The Permittee requested alternative effluent limits for thermal discharges consistent with Regs. Conn. State Agencies Section 22a-430-4(q)(2)(A)(ii) and 40 CFR 125 Subpart H. THERMAL EVALUATION Section 316(a) of the federal Water Pollution Control Act, U.S.C. § 1326(a) requires that the thermal component of any discharge assure the protection and propagation of a balanced indigenous population of shellfish, fish and wildlife in and on the receiving water body. The segment of Quinebaug River where the discharge is located is classified as "B" under the WQS. The applicable WQS for a class “B” surface water is: "There shall be no changes from natural conditions that would impair any existing or designated uses assigned to this class and, no case exceed 84oF, or in any case raise the temperature of surface water more than 4oF. (Regs. Conn. State Agencies 22a-426-9(a)(1)). The Permittee discharges a heat load to the Quinebaug River from NCCW (DSN 101-1). The permit issued on August 30, 2013, contained a temperature limitation of 90oF which is proposed to be carried forward. For the previous permit issuance, EPA’s modeling software "Visual Plumes" was used to model the characteristics of the expected thermal plume associated with the discharge of heat load to the Quinebaug River. The software generated a three-dimensional model of the geometry of the thermal plume under the assumption that the discharge and ambient flow conditions are in a steady state. The submerged discharge pipe is six inches in diameter and has a single port diffuser, which results in the discharge favoring rapid mixing. The location of the single port outfall pipe was selected and designed so the discharge occurs at the center of the river, where the water depths are at a maximum, and located approximately 100 ft downstream from the intake pipe. This is consistent with EPA’s recommendations that cooling water systems should optimize the dissipation of heat and minimize the area affected by excessive temperatures. Furthermore, the design is consistent with EPA’s emphasis that thermal discharges should be in areas with good flushing characteristics and should minimize the addition of heat into receiving waters (U.S. Environmental Protection Agency (U.S. EPA). 2023. Thermal Discharges in NPDES Permits, Overview of Resources and Tools (EPA-833- F-23-007). pp 163, 188-189). A review of temperature data for the past five years showed a discharge temperature range of 60.79 – 89.99oF, with an average of 83.07oF. The intake temperature ranged from 49.01 – 86.59oF, with an average of 66.98oF. The temperature difference between the intake and the discharge ranged from 7.39 – 71.94oF, with an average differential temperature of 27.95oF. A new thermal model was performed using EPA’s PLUMES2.0 software, designed to simulate effluent plume dilution. The result showed the areas of modeled thermal plumes are comparable to the areas of the previously modeled thermal plumes, though a little smaller. The percentages of the cross-sectional areas of the thermal plume under low flow (84 cfs) and mean flow (1,030 cfs) conditions are less than 1% of the cross-sectional area of the receiving river, as shown in Tables 3.16.1 and 3.16.2. The CT WQS allows for a “zone of influence for assimilation of a thermal discharge shall be no greater than 25% of the cross-sectional area or volume of flow of the receiving water” (Regs. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 30 of 43 December 2025 [Page 61] Conn. State Agencies 22a-426-4(l)(8)). The thermal cross-sectional areas in the thermal model are well below the allowable thermal zone of influence of 25%. The Permittee was required to conduct a thermal verification study to confirm the thermal modeling under the previous permit, but the Permittee did not receive DEEP approval of the scope of studies by the time of this permit renewal (see Section 1.8.3 of this fact sheet). The thermal modeling results from the previous permit are presented in Tables 3.16.1 and 3.16.2. They show a differential temperature (discharge – ambient) of 57.4oF. As stated above, the actual differential temperatures ranged from 7.39 – 71.94oF, with an average differential temperature of 27.95oF. While the cross-sectional areas of thermal plumes in the model are about 1% of the cross-sectional area of the river, the actual maximum differential temperature (intake – discharge) from discharge monitoring data is about 15oF higher than the differential temperature used in the model. Therefore, it is necessary to verify that the thermal plume is representative of a higher differential temperature situation, and the discharge will not cause an increase higher than 4oF outside of the thermal zone of influence. A thermal verification study is incorporated in this permit renewal as a compliance schedule, to confirm the actual thermal plume size, and ensure that the discharge is consistent with the thermal model result. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 31 of 43 December 2025 [Page 62] Quinebaug River Low Flow Conditions Table 3.16.1: Thermal Plume Modeling under Quinebaug River Low Flow Conditions Parameter Scenario 1: Scenario 2: Scenario 3: Plume Boundary Condition Plume Boundary Condition Plume Boundary Condition o 1 of Δ4oF of the Ambient 2 of 85 F Temperature 1 with Ambient Temperature Minimum Maximum Minimum Maximum Minimum Maximum Observed Observed Observed Observed Observed Observed Ambient Ambient Ambient Ambient Ambient Ambient Temperature Temperature Temperature Temperature Temperature Temperature (32.6oF) (85.9oF) (32.6oF) (85.9oF) (32.6oF) (85.9oF) River Flow 84 84 84 84 84 84 (cfs) Discharge 90 90 90 90 90 90 Temp. (oF) River depth 10 10 10 10 10 10 (ft.) Discharge port diameter 6 6 6 6 6 6 (inches) Discharge port depth 8 8 8 8 8 8 (ft.) Maximum 0.173 0.173 0.173 0.173 0.173 0.173 flow (MGD) Temp.at the end of plume 85 85 36.6 89.9 35.37 86.04 (oF) Plume length 0.16 --- 20.9 0.2 26.48 31.73 (ft) Plume 0.54 --- 2.88 0.54 3.51 4.21 diameter (ft.) Depth to center line of 4.0 --- 3.83 4.0 4.28 2.19 plume (ft.) Cross- sectional 0.2 --- 6.53 0.23 9.7 13.94 Area of plume (sq ft) 3 % River 0.25% --- 1.34% 0.25% 1.63% 1.97% Width 4 % of River cross- 0.02% --- 0.45% 0.02% 0.68% 0.97% sectional Area 5 1 Modeled plume data are based on interpolation of the two temperature data points bounding the targeted boundary plume temperature. 2 Data provided represents the model output closet to the river ambient temperature. 3 Model assumed that the cross-sectional area of the plume is circular hence, area was calculated using the formula = πr2. 4 River width was assumed to be 215 ft. at the point of discharge. 5 Cross-sectional area of the river was estimated to be 1435 sq ft. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 32 of 43 December 2025 [Page 63] Quinebaug Mean Low Flow Conditions Table 3.16.2: Thermal Plume Modeling under Quinebaug River Mean Flow Conditions Scenario 1: Scenario 2: Scenario 3: Plume Boundary Condition Plume Boundary Condition Plume Boundary Condition o 1 of Δ4oF of the Ambient 2 of 85 F Temperature 1 with Ambient Temperature Minimum Maximum Minimum Maximum Minimum Maximum Observed Observed Observed Observed Observed Observed Ambient Ambient Ambient Ambient Ambient Ambient Temperature Temperature Temperature Temperature Temperature Temperature (32.6oF) (85.9oF) (32.6oF) (85.9oF) (32.6oF) (85.9oF) River Flow 1030 1030 1030 1030 1030 1030 (cfs) Discharge 90 90 90 90 90 90 Temp. (oF) River depth 10 10 10 10 10 10 (ft.) Discharge port diameter 6 6 6 6 6 6 (inches) Discharge port depth 8 8 8 8 8 8 (ft.) Maximum 0.173 0.173 0.173 0.173 0.173 0.173 flow (MGD) Temp.at the end of plume 85 85 36.6 89.9 35.16 86.05 (oF) Plume length 0.17 --- 22.89 0.06 30.22 32.61 (ft) Plume 0.53 --- 2.71 0.51 3.39 3.86 diameter (ft) Depth to center line of 8.0 --- 7.8 8.0 - 8.29 - 6.34 plume (ft) Cross- sectional 0.22 --- 5.75 0.2 9.04 11.67 Area of plume (sq ft) 3 % River 0.25% --- 1.3% 0.2% 1.58% 1.79% Width 4 % of River cross- 0.02% --- 0.4% 0.01% 0.63% 0.81% sectional Area 5 1 Modeled plume data are based on interpolation of the two temperature data points bounding the targeted boundary plume temperature. 2 Data provided represents the model output closet to the river ambient temperature. 3Model assumed that the cross-sectional area of the plume is circular hence, area was calculated using the formula = πr2. 4 River width was assumed to be 215 ft. at the point of discharge. 5 Cross-sectional area of the river was estimated to be 1435 sq ft. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 33 of 43 December 2025 [Page 64] 3.19 E-Reporting The Permittee is required to electronically submit documents in accordance with 40 CFR Section 127. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 34 of 43 December 2025 [Page 65] Section 4 Summary of New Permit Conditions and Limits from the Previous Permit The following changes were made from the previous permit: • This permit was previously assigned two permit numbers: Permit Nos. CT0030473 and SP0002464. Groundwater discharges from DSNs 102, 103, and 104 were associated with Permit No. SP0002464. Permit No. SP0002464 has been terminated and removed from this permit. All discharges, including DSNs 102, 103, and 104 are now covered under Permit No. CT0030473. • DSN 105 – The demineralized water tank is now situated inside the power generating facility and overflows will discharge via floor drains to the sanitary sewer system. The discharge is covered under the “General Permit for Discharges from Miscellaneous Industrial Users (MIU GP)”, and therefore removed from the permit. • Monitoring requirements for chromium were added for DSN 101-1 because chromium is present in the wastewater. • A one-time monitoring requirement for 126 priority pollutants, except chromium and zinc, was added for DSN 101-1 because the 126 priority pollutants include contaminants potentially contained in chemicals added for cooling tower maintenance. Routine chromium and zinc monitoring are required on a weekly basis and therefore not included in this priority pollutant scan. • Monitoring tables for acute and chronic toxicity testing (DSN 101-AT and DSN 101-CT) have been added to the permit. This table does not change the testing requirements, rather it changes the way the acute and chronic toxicity monitoring data is reported by the Permittee. The Permittee is now required to electronically report toxicity results and paired chemical and receiving water data through NetDMR with the monthly DMR report. • Monitoring requirements for aluminum at DSN 103-1 were added because the water discharged is the same quality as DSN 102-1, and aluminum is a pollutant of concern. • With the exception of chlorine, mass limits were included for aluminum, copper and lead because a reasonable potential analysis showed that water quality-based limits are needed for these pollutants. • Turbidity monitoring requirement was removed from the permit because the average turbidity was 2.84 Nephelometric Turbidity Unit (“NTU”), showing that the discharge is not exceeding 5 NTU over ambient levels and not exceeding levels necessary to protect and maintain all designated uses, consistent with CT WQS (Regs. Conn. State Agencies 22a-426-9(a)(1). • Effluent limits where applicable are expressed in Table A, while Table B now contains toxicity limits and monitoring requirements (without limits) for other pollutants. • A compliance schedule to perform a thermal verification study was added to the permit. • Section 5(A)(5) of the permit that required the Permittee to construct, operate and maintain the cooling water intake structure in accordance with the submitted mitigation and monitoring plan has been removed. This is because the Permittee completed the required mitigation and monitoring in December 2021. • The effluent limits for pH were changed from 6.0 – 9.0 S.U. to 6.5 – 8.0 S.U. consistent with the water quality criteria for a class “B” waterbody. • A compliance schedule requiring the Permittee to evaluate alternate actions to achieve compliance with the proposed pH limits was added to the permit. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 35 of 43 December 2025 [Page 66] Section 5 Public Participation Procedures 5.1 Information Requests The application has been assigned the following numbers by the Department of Energy and Environmental Protection. Please use these numbers when corresponding with this office regarding this application. Application No. 201801971 Permit No. CT0030473 Interested persons may obtain copies of the application from Mark Boucher, Plainfield Renewable Energy, LLC, 12 Mill Brook Road, CT 06374. The application is available for inspection by contacting Oluwatoyin Fakilede at Oluwatoyin.fakilede@ct.gov, at the Department of Energy and Environmental Protection, Bureau of Materials Management and Compliance Assurance, 79 Elm Street, Hartford, CT 06106-5127 from 8:30 - 4:30, Monday through Friday. Any interested person may request in writing that his or her name be put on a mailing list to receive notice of intent to issue any permit to discharge to the surface waters of the state. Such request may be for the entire state or any geographic area of the state and shall clearly state in writing the name and mailing address of the interested person and the area for which notices are requested. 5.2 Public Comment Prior to making a final decision to approve or deny any application, the Commissioner shall consider written comments on the application from interested persons that are received within 30 days of this public notice. Written comments should be directed to Oluwatoyin Fakilede, Environmental Engineer 3, Bureau of Materials Management and Compliance Assurance, Department of Energy and Environmental Protection, 79 Elm Street, Hartford, CT 06106-5127 or DEEP.IndustrialNPDESPublicComments@ct.gov and should indicate the Permit ID No. CT0030180 in the subject line. The Commissioner may hold a public hearing prior to approving or denying an application if in the Commissioner's discretion the public interest will be best served thereby, and shall hold a hearing upon receipt of a petition signed by at least twenty five (25) persons. Notice of any public hearing shall be published at least thirty (30) days prior to the hearing. Petitions shall be submitted within thirty (30) days from the date of publication of this public notice and should include the application number noted above and also identify a contact person to receive notifications. Petitions may also identify a person who is authorized to engage in discussions regarding the application and, if resolution is reached, withdraw the petition. Upon receipt of a petition, the Commissioner shall take action as required by relevant laws, including Public Act 25- 84, which was effective upon passage in June 2025. The Office of Adjudications will accept electronically-filed petitions for hearing in addition to those submitted by mail or hand-delivered. Petitions with required signatures may be sent to deep.adjudications@ct.gov; those mailed or delivered should go to the DEEP Office of Adjudications, 79 Elm Street, Hartford, CT 06106. If the signed original petition is only in an electronic format, the petition must be submitted with a statement signed by the petitioner that the petition exists only in that form. Original petitions that were filed electronically must also be mailed or delivered to the Office of Adjudications within 30 days of electronic submittal. Additional information can be found at www.ct.gov/deep/adjudications. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 36 of 43 December 2025 [Page 67] The Connecticut Department of Energy and Environmental Protection is an Affirmative Action/Equal Opportunity Employer that is committed to complying with the requirements of the Americans with Disabilities Act (ADA). If you are seeking a communication aid or service, have limited proficiency in English, wish to file an ADA or Title VI discrimination complaint, or require some other accommodation, including equipment to facilitate virtual participation, please contact the DEEP Office of Diversity and Equity at 860-418-5910 or by email at deep.accommodations@ct.gov. Any person needing an accommodation for hearing impairment may call the State of Connecticut relay number - 711. In order to facilitate efforts to provide accommodation, please request all accommodations as soon as possible following notice of any agency hearing, meeting, program, or event. Appendix A: Zone of Influence Determination Memo Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 37 of 43 December 2025 [Page 68] Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 38 of 43 December 2025 [Page 69] Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 39 of 43 December 2025 [Page 70] Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 40 of 43 December 2025 [Page 71] Appendix B: Reasonable Potential Analysis and Water Quality Based Limits Calculations Section B1: Facility Information Section B2: Reasonable Potential Analysis Result Section B3: Water Quality Based Limits Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 41 of 43 December 2025 [Page 72] Section B4: Reasonable Potential Analysis for Ammonia Section 22a-426-9 of the Regs. Conn. State Agencies specifies water quality criteria for ammonia based on the presence or absence of salmonids. Upstream of the Permittee’s discharge is Moosup River. The Moosup River discharges to Quinebaug River and is under the Trout Management Area. Therefore, salmonids may be present in the Quinebaug River. The criteria for ammonia when salmonids are present is used below. Criteria for ammonia, (mg/L as Nitrogen) vary in response to ambient surface water temperature (T in oC) and pH. Biological integrity is considered impaired when: A) One-hour average concentration of total ammonia exceeds: ([ 0.275 ] + [ 39 ]) when salmonids are present or 1+107.204−pH 1+10pH−7.204 ([ 0.411 ] + [ 58.4 ]) when salmonids are absent. 1+107.204−pH 1+10pH−7.204 B) Four-day average concentration of total ammonia exceeds: 30-day average x 2.5 C) 30-day average concentration of total ammonia exceeds: [ 0.0577 ] + [ 2.487 ] x ⌈MIN(2.85, 1.45 x (100.028(25−T)))⌉ when early life stages are 1+107.688−pH 1+10pH−7.688 present, or [ 0.0577 ] + [ 2.487 ] x ⌈1.45 x (100.028(25−MAX(T,7))))⌉ when early life stages are 1+107.688−pH 1+10pH−7.688 absent. Ambient monitoring data collected by the US Geological Survey for the Quinebaug River at Jewett City (USGS-01127000) for the period of January 2020 – December 2024 was used to calculate the water quality criteria at the Quinebaug River. (How's My Waterway - Water Monitoring Report) Table B4.1: Ambient data for pH and Temperature Parameter Months Average Minimum Maximum pH (S.U.) April - October 7.4 7.1 7.8 November - March 7.26 7.0 7.5 Temperature April - October 20.8 13.6 28.2 (o Celsius) November - March 5.9 1.1 14.6 Spawning can occur in the spring, summer or fall depending on the salmon species. Therefore, the criteria for early stages are used for the reasonable potential analysis. Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 42 of 43 December 2025 [Page 73] November – March: April - October: Table B4.2: Ammonia Criteria Summary Months Acute 30 Day Average 4 Day Average November - March 19.06 mg/l 5.3 mg/l 13.25 mg/l April - October 15.34 mg/l 4.73 mg/l 11.83 mg/l The maximum reported total ammonia from November – March is 7,700 µg/l. The maximum reported total ammonia from April – October is 7,000 µg/l. The coefficient of variance was calculated to be 2.0. Table B4.3: Reasonable Potential Evaluation (This analysis compares the projected maximum concentration (PMC) in the receiving stream with the applicable water quality criteria (WQC). When the PMC is lower than the WQC, there is no potential for the discharge to exceed the WQC. When the PMC is higher than the WQC, there is a potential for the discharge to exceed the WQC and permit limits are therefore needed.) Q = Flow, C = Concentration, (QC)u = Upstream data, (QC)d = Downstream data, (QC)e = Effluent data, Qd = Qu + Qe. Qe,ac = 126,103 gpd ÷ 16 = 7,881 gph, Qe,ch = 126,103 gpd ÷ 24 = 5,254 gph, Qu, = 137,750 gph, Qd, ac, = 145,631 gph and Qd, ch, = 143,004 gph Pollutants PMC in effluent = PMC in the Connecticut Water Quality Is there Maximum measured waterbody Cd = Criteria (WQC) (Freshwater) potential concentration X (QC)u+(QC)e(µg/l) Aquatic Life Aquatic Life to exceed multiplier in Qd (Acute) (Chronic) WQC? Table 3-1 of the TSD (µg/l) (µg/l) Ammonia 7,700 X 7.1 = 54,670 Acute: 2,959 19,060 5,300 No (Nov.– Mar.) Chronic: 2,008 Ammonia 7,000 X 6.8 = 47,600 Acute: 2,576 15,340 4,730 No (Apr. – Oct.) Chronic: 1,749 Draft NPDES Permit No. CT0030473 Draft Fact sheet Page 43 of 43 December 2025 [Page 74] portal.ct.gov/DEEP NOTICE OF TENTATIVE DETERMINATION INTENT TO RENEW A NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM PERMIT FOR THE FOLLOWING DISCHARGES INTO THE WATERS OF THE STATE OF CONNECTICUT 1.0 TENTATIVE DECISION The Commissioner of the Department of Energy and Environmental Protection (“the Commissioner”) hereby gives notice of a tentative determination to renew a permit based on an application and administrative record submitted by P lainfield Renewable Energy, LLC (“the Applicant”) under Section 22a-430 of the Connecticut General Statutes (“CGS”) for a permit to discharge into the waters of the state. The proposed permit authorizes discharges to the Quinebaug River and the groundwaters in the Mill Brook watershed under National Pollutant Discharge Elimination System (“NPDES”) Permit No. CT0030473. The tentative determination include s a termination of Permit No. SP0002464. The g roundwater discharges from DSNs 102, 103, and 104 were previously associated with Permit No. SP0002464. Reference to Permit No. SP0002464 has been removed from the proposed permit, and all discharges, including DSNs 102, 103, and 104, are proposed to be covered under Permit No. CT0030473. The tentative decision to renew the permit also includes the following determinations: • The permit will assure the protection and propagation of a balanced indigenous population of shellfish, fish and wildlife in and on the receiving waters under Section 316(a) of the Clean Water Act, 33 U.S.C. § 1326(a); • A determination of best technology available under Section 316(b) of the Federal Water Pollution Control Act, 33 U.S.C. § 1326(b); and • In accordance with applicable federal and state law, the Commissioner has made a tentative determination that continuance of the existing system to treat the discharge would protect the waters of the state from pollution. The proposed permit, if issued by the Commissioner, will require that some wastewater s are treated to meet the applicable effluent limitations and periodic monitoring to demonstrate that the discharge will not cause pollution. 2.0 APPLICANT'S PROPOSAL Plainfield Renewable Energy, LLC presently discharges wastewater from operations associated with an electricity power generating facility . The Applicant discharges 173,571 gallons per day of cooling water blowdown directly to the Quinebaug River . 79 Elm Street An Affirmative Action/Equal Opportunity Employer Hartford, CT 06106-5127 860.424.3000 [Page 75] In addition, once per year, the Applicant discharges 225,000 gallons per day of fire pump test water, 225,000 gallons per day of fire hydrant test water, and 250,000 gallons per day of make-up supply tank drain and overflow wastewater to the groundwater in the Quinebaug River watershed . The name and mailing address of the permit Applicant are: Plainfield Renewable Energy, LLC, 12 Mill Brook Road, Plainfield, CT 06374 The activity takes place at: 12 Mill Brook Road, Plainfield, CT 06374 and the pump house is at 114 Packer Road, Canterbury, CT 06331. 3.0 REGULATORY CONDITIONS 3.1 Type of Treatment DSN 101: Cooling tower blowdown – Treatment includes filtration, dechlorination using sodium bisulfite and pH adjustment. DSN 102: Fire pump test wastewater - Wastewater is not treated . DSN 103: Fire hydrant test wastewater - Wastewater is not treated. DSN 104: Make-up supply tank drain and overflow wastewaters - Wastewater is not treated. Water Intake 101-H: Cooling Water Intake Structure – Cylindrical wedge wire screen to minimize impingement and entrainment; and Water Intake 101- H: Intake cooling water – Neutralization, coagulation, flocculation, clarification, filtration of intake water treatment to meet required process water quality, on as needed basis. 3.2 Effluent Limitations This permit contains effluent limitations consistent with a Case-by-Case Determination using the criteria of Best Professional Judgement and which will protect the waters of the state from pollution when all the conditions of this permit have been met. In accordance with S ection 22a-430-4(l) of the Regulations of Connecticut State Agencies the permit contains effluent limitations for the following types of toxic substances: heavy metals and total residual chlorine. This permit contains the following variances from the effluent limitations required by Section 22a-430-4(l) of the Regulations of Connecticut State Agencies. 3.3 Compliance Schedule This permit contains enforceable compliance schedules which require the A pplicant to: 1. Conduct a thermal verification study and submit the report for the Commissioner’s review and concurrence; and 2. Propose alternative actions and implement the preferred action(s) to achieve compliance with pH effluent limitations contained in the permit. [Page 76] 4.0 COMMISSIONER’S AUTHORITY The Commissioner is authorized to approve or deny such permits pursuant to S ection 402(b) of the Federal Water Pollution Control Act, as amended, 33 USC 1251, et . seq . and Section 22a-430 of the CGS and the Water Discharge Permit Regulations ( Section 22a-430-3 and 4 of the RCSA). 5.0 INFORMATION REQUESTS The application has been assigned the following numbers by the Department of Energy and Environmental Protection. Please use these numbers when corresponding with this office regarding this application. APPLICATION NO. 201801917 PERMIT ID NO. CT0030473 Interested persons may obtain copies of the application from Mark Boucher, Plainfield Renewable Energy, LLC., 12 Mill Brook Road, Plainfield, CT 06374, mboucher@plainfieldre.com , (860) 457-9307. The application is available for inspection by contacting Oluwatoyin Fakilede, Environmental Engineer 3, at 860-424- 3025 or oluwatoyin.fakilede@ct.gov , at the Department of Energy and Environmental Protection, Bureau of Materials Management and Compliance Assurance, 79 Elm Street, Hartford, CT 061065127 from 8:30-4:30, Monday through Friday. Any interested person may request in writing that his or her name be put on a mailing list to receive notice of intent to issue any permit to discharge to the surface waters of the state. Such request may be for the entire state or any geographic area of the state and shall clearly state in writing the name and mailing address of the interested person and the area for which notices are requested. 6.0 PUBLIC COMMENT Prior to making a final decision to approve or deny any application, the Commissioner shall consider written comments on the application from interested persons that are received within 30 days of this public notice. Written comments should be directed to Oluwatoyin Fakilede, Environmental Engineer 3, Bureau of Materials Management and Compliance Assurance, Department of Energy and Environmental Protection, 79 Elm Street, Hartford, CT 061065127 or DEEP.IndustrialNPDESPublicComments@ct.gov and should indicate Plainfield Renewable Energy, LLC and the Permit ID No. CT0030473 in the subject line . The Commissioner may hold a public hearing prior to approving or denying an application if in the Commissioner's discretion the public interest will be best served thereby, and shall hold a hearing upon receipt of a petition signed by at least twenty -five persons. Notice of any public hearing shall be published at least thirty (30) days prior to the hearing. [Page 77] 7.0 PETITIONS FOR HEARING Petitions shall be submitted within thirty (30) days from the date of publication of this public notice and should include the application number noted above and also identify a contact person to receive notifications. Petitions may also identify a person who is authorized to engage in discussions regarding the application and, if resolution is reached, withdraw the petition. Upon receipt of a petition, the Commissioner shall take action as required by relevant laws, including Public Act 25-84, which was effective upon passage in June 2025. The Office of Adjudications will accept electronically -filed petitions for hearing in addition to those submitted by mail or hand- delivered. Petitions with required signatures may be sent to deep.adjudications@ct.gov; those mailed or delivered should go to the DEEP Office of Adjudications, 79 Elm Street, Hartford, CT 06106. If the signed original petition is only in an electronic format, the petition must be submitted with a statement signed by the petitioner that the petition exists only in that form. Original petitions that were filed electronically must also be mailed or delivered to the Office of Adjudications within 30 days of electronic submittal. Additional information can be found at www.ct.gov/deep/adjudications . The Connecticut Department of Energy and Environmental Protection is an Affirmative Action/Equal Opportunity Employer that is committed to complying with the requirements of the Americans with Disabilities Act (ADA). If you are seeking a communication aid or service, have limited proficiency in English, wish to file an ADA or Title VI discrimination complaint, or require some other accommodation, including equipment to facilitate virtual participation, please contact the DEEP Office of Diversity and Equity at 860-418- 5910 or by email at deep.accommodations@ct.gov. Any person needing an accommodation for hearing impairment may call the State of Connecticut relay number - 711. In order to facilitate efforts to provide accommodation, please request all accommodations as soon as possible following notice of any agency hearing, meeting, program, or event ___________________________________ Audra Dickson, Director Water Permitting and Enforcement Division Bureau of Materials Management and Compliance Assurance Department of Energy and Environmental Protection Dated: December 3, 2025