ALASKA POLLUTANT DISCHARGE ELIMINATION SYSTEM PERMIT FACT SHEET PRELIMINARY DRAFT Permit Number: AK

Transcription

1 ALASKA POLLUTANT DISCHARGE ELIMINATION SYSTEM PERMIT FACT SHEET PRELIMINARY DRAFT Permit Number: AK City of Kodiak Wastewater Treatment Facility ALASKA DEPARTMENT OF ENVIRONMENTAL CONSERVATION Wastewater Discharge Authorization Program 555 Cordova Street Anchorage, AK Public Comment Period Start Date: DRAFT Public Comment Period Expiration Date: DRAFT Alaska Online Public Notice System Technical Contact: Melinda Smodey Alaska Department of Environmental Conservation Division of Water Wastewater Discharge Authorization Program 555 Cordova Street Anchorage, AK (907) Fax: (907) Proposed issuance of an Alaska Pollutant Discharge Elimination System (APDES) permit to For wastewater discharges from CITY OF KODIAK City of Kodiak Wastewater Treatment Facility 2853 Spruce Cape Road Kodiak, AK The Alaska Department of Environmental Conservation (the Department or DEC) proposes to reissue an APDES individual permit (permit) to the City of Kodiak. The permit authorizes and sets conditions on the discharge of pollutants from this facility to waters of the United States. In order to ensure protection of water quality and human health, the permit places limits on the types and amounts of pollutants that can be discharged from the facility and outlines best management practices to which the facility must adhere. Page 1 of 58

2 This fact sheet explains the nature of potential discharges from the City of Kodiak Wastewater Treatment Facility and the development of the permit including: information on public comment, public hearing, and appeal procedures a listing of proposed effluent limitations and other conditions technical material supporting the conditions in the permit proposed monitoring requirements in the permit Public Comment Persons wishing to comment on, or request a public hearing for the draft permit for this facility, may do so in writing by the expiration date of the public comment period. Commenters are requested to submit a concise statement on the permit condition(s) and the relevant facts upon which the comments are based. Commenters are encouraged to cite specific permit requirements or conditions in their submittals. A request for a public hearing must state the nature of the issues to be raised, as well as the requester s name, address, and telephone number. The Department will hold a public hearing whenever the Department finds, on the basis of requests, a significant degree of public interest in a draft permit. The Department may also hold a public hearing if a hearing might clarify one or more issues involved in a permit decision or for other good reason, in the Department s discretion. A public hearing will be held at the closest practicable location to the site of the operation. If the Department holds a public hearing, the Director will appoint a designee to preside at the hearing. The public may also submit written testimony in lieu of or in addition to providing oral testimony at the hearing. A hearing will be tape recorded. If there is sufficient public interest in a hearing, the comment period will be extended to allow time to public notice the hearing. Details about the time and location of the hearing will be provided in a separate notice. All comments and requests for public hearings must be in writing and should be submitted to the Department at the technical contact address, fax, or identified above (see also the public comments section of the attached public notice). Mailed comments and requests must be postmarked on or before the expiration date of the public comment period. After the close of the public comment period and after a public hearing, if applicable, the Department will review the comments received on the draft permit. The Department will respond to the comments received in a Response to Comments document that will be made available to the public. If no substantive comments are received, the tentative conditions in the draft permit will become the proposed final permit. The proposed final permit will be made publicly available for a five-day applicant review. The applicant may waive this review period. After the close of the proposed final permit review period, the Department will make a final decision regarding permit issuance. A final permit will become effective 30 days after the Department s decision, in accordance with the state s appeals process at 18 AAC The Department will transmit the final permit, fact sheet (amended as appropriate), and the Response to Comments to anyone who provided comments during the public comment period or who requested to be notified of the Department s final decision. The Department has both an informal review process and a formal administrative appeal process for final APDES permit decisions. An informal review request must be delivered within 15 days after receiving the Department s decision to the Director of the Division of Water at the following address: Director, Division of Water Alaska Department of Environmental Conservation 410 Willoughby Street, Suite 303 Juneau AK, Page 2 of 58

3 Interested persons can review 18 AAC for the procedures and substantive requirements regarding a request for an informal Department review. See for information regarding informal reviews of Department decisions. An adjudicatory hearing request must be delivered to the Commissioner of the Department within 30 days of the permit decision or a decision issued under the informal review process. An adjudicatory hearing will be conducted by an administrative law judge in the Office of Administrative Hearings within the Department of Administration. A written request for an adjudicatory hearing shall be delivered to the Commissioner at the following address: Commissioner Alaska Department of Environmental Conservation 410 Willoughby Street, Suite 303 Juneau AK, Interested persons can review 18 AAC for the procedures and substantive requirements regarding a request for an adjudicatory hearing. See for information regarding appeals of Department decisions. Documents are Available The permit, fact sheet, application, and related documents can be obtained by visiting or contacting DEC between 8:00 a.m. and 4:30 p.m. Monday through Friday at the addresses below. The permit, fact sheet, application, and other information are located on the Department s Wastewater Discharge Authorization Program website: Alaska Department of Environmental Conservation Division of Water Wastewater Discharge Authorization Program 555 Cordova Street Anchorage, AK (907) Alaska Department of Environmental Conservation Division of Water Wastewater Discharge Authorization Program 410 Willoughby Avenue, Suite 310 Juneau, AK (907) Alaska Department of Environmental Conservation Division of Water Wastewater Discharge Authorization Program Kalifornsky Beach Rd. - Suite 11 Soldotna, AK (907) Page 3 of 58

4 TABLE OF CONTENTS 1.0 APPLICANT FACILITY INFORMATION Permit Background COMPLIANCE HISTORY EFFLUENT LIMITS AND MONITORING REQUIREMENTS Basis for Permit Effluent Limits Basis for Effluent and Receiving Water Monitoring Pollutants of Concern Influent and Effluent Limits and Monitoring Requirements Whole Effluent Toxicity Monitoring Receiving Water Body Limits and Monitoring Requirements RECEIVING WATER BODY Description of Receiving Water Body Outfall Location Water Quality Standards Water Quality Status of Receiving Water Mixing Zone Analysis ANTIBACKSLIDING ANTIDEGRADATION OTHER PERMIT CONDITIONS Quality Assurance Project Plan Operation and Maintenance Plan Industrial User Survey Electronic Discharge Monitoring Report Compliance Schedule Standard Conditions OTHER LEGAL REQUIREMENTS Ocean Discharge Criteria Endangered Species Act Essential Fish Habitat Sludge (Biosolids) Requirements Permit Expiration References Page 4 of 58

5 TABLES Table 1: Effluent Data Summary... 7 Table 2: Discharge Permit History... 8 Table 3: Expanded Effluent Tests Detected Pollutants Table 4: Effluent Monitoring and Limit Changes from Prior Permit Table 5: Influent and Effluent Limits and Monitoring Requirements Table 6: Analytical Results Shoreline and Mixing Zone Boundary Table 7: Receiving Water Monitoring Requirements Table 8: Diffuser Configuration Table 9: Summary of CORMIX Model Inputs Table 10. Interim FC Bacteria Effluent Limits Table B- 1: Secondary Treatment Effluent Limits Table B- 2: BOD5 Percent Removal <85% Table B- 3: BOD5 and TSS Concentrations Table B- 4: Summary of Effluent Limitations Table C- 1: Reasonable Potential Analysis Results FIGURES Figure 1: Approximate Mixing Zone Location...24 Figure 2: Wastewater Treatment Plant Vicinity Map...38 Figure 3: City of Kodiak WWTF Outfall Map...39 Figure 4: Wastewater Treatment Plant Process Flow Diagram...40 LIST OF APPENDICES APPENDIX A. FACILITY INFORMATION APPENDIX B. BASIS FOR EFFLUENT LIMITATIONS APPENDIX C. REASONABLE POTENTIAL DETERMINATION APPENDIX D. EFFLUENT LIMIT CALCULATION APPENDIX E. MIXING ZONE CHECKLIST.56 Page 5 of 58

6 1.0 APPLICANT This fact sheet provides information on the Alaska Pollutant Discharge Elimination System (APDES) permit for the following entity: Name of Facility: City of Kodiak Wastewater Treatment Facility APDES Permit Number: AK Facility Location: 2853 Spruce Cape Road, Kodiak, AK Mailing Address: 2410 Mill Bay Road, Kodiak, AK Facility Contact: Mr. Constantino Bormuel The map in APPENDIX A, Figure 2 shows the location of the treatment plant. The map in APPENDIX A, Figure 3 shows the location of the outfall. The process flow diagram in APPENDIX A, Figure 4 illustrates the treatment process. 2.0 FACILITY INFORMATION The City of Kodiak (City) is located on the east side of the island of Kodiak in the Gulf of Alaska. The City owns, operates, and maintains the municipal Wastewater Treatment Facility (WWTF) that provides secondary treatment of wastewater prior to discharge in Woody Island Channel through Outfall 001. Woody Island Channel separates Kodiak and Woody Islands by approximately one kilometer in the proximity of the WWTF outfall. The WWTF was originally placed into service in The WWTF receives domestic wastewater from residential and commercial sources; there are no known significant industrial users. The WWTF was expanded and upgraded in 1999 and 2000 and serves a population of approximately 6,130, with a design flow of 3.2 million gallons per day (MGD). Influent wastewater is pumped to the headworks of the WWTF where flow is measured prior to debris removal via two rotary drum fine screens. Screened solids are discharged to a compactor, limed, and disposed of at the Kodiak Island Borough Landfill. Screened influent flows to a sump below the rotary screens. A composite influent sample is collected from the sump. The screened influent flows via gravity to the primary clarifier. The primary clarifier is located outdoors and is 70 feet in diameter and 10 feet deep. A rotating mechanism scrapes the bottom of the clarifier, pushing settled solids to a center hopper from which the solids can be removed to the primary sludge tank prior to dewatering. The primary sludge tank includes an activated carbon air scrubber to treat odor. Floatable material is removed from the primary clarifier and pumped back to the treatment plant influent sump where it is screened. Primary clarifier supernatant flows over a weir and is mixed with return activated sludge (RAS) prior to being transmitted to the aeration basins. Primary treated effluent is split between two outdoor aeration basins where secondary treatment via activated sludge occurs. Soluble organic material and some of the particulate material in the wastewater is treated by microorganisms. Blowers introduce air into the aeration basins via fine bubble membrane diffusers. From the aeration basins, the effluent flows to two 60 foot diameter, 12 foot deep covered secondary clarifiers for further settling prior to discharge. A third covered secondary clarifier is available as a backup. A portion of the settled sludge is pumped to a gravity thickener as waste activated sludge (WAS) for disposal. Another portion of settled sludge is pumped to the aerations basins as RAS to assist secondary treatment. Scum is removed from the secondary clarifiers to a scum sump where it is pumped back to the headworks. Treated effluent flows over a weir and into a trough. The treated effluent is collected and transmitted to the effluent building, where a composite sampler is located. The effluent building contains chlorine contact chambers, although the effluent is not currently disinfected prior Page 6 of 58

7 to discharge. An effluent flow meter measures flow prior to discharge to Woody Island Channel. Effluent is transmitted for discharge to Woody Island Channel through a buried 900 foot long, 18 inch diameter outfall. The City of Kodiak WWTF accepts sludge, primarily WAS, from the United States Coast Guard Base (USCG) Kodiak WWTF. WAS from the secondary clarifiers, primary sludge from the primary clarifiers, and USCG sludge from the USCG sludge tank is sent to the gravity thickener. All three sludges are blended prior to dewatering in the blend tank so that a uniform product is sent to the belt press for dewatering. Solids settle to the bottom of the gravity thickener, where a rotating mechanism pushes settled, thickened sludge to a center hopper. Supernatant and scum flows over a weir to a sump where it is pumped back to the WWTF headworks. A polymer is applied to aid the dewatering process. Dewatered sludge cakes are transported to the City of Kodiak s solid waste composting facility located at 855 Monashka Bay Road. At the composting facility, sludge cakes are mixed with a wood amendment and processed using the negative aerated static pile method. Sludge is composted and distributed for use. Table 1 summarizes the City of Kodiak WWTF effluent monitoring data for the time period June 2012 through June 2017, which was the most recent five years of effluent data available. Table 1: Effluent Data Summary Pollutant Units Range (Minimum-Maximum) Average Ammonia Milligrams per liter (mg/l) Non Detect (ND) Five Day Biochemical Oxygen Demand (BOD 5) mg/l Daily Maximum BOD 5 Monthly Average mg/l BOD 5 Percent Removal Percent (%) BOD 5 Weekly Average mg/l Dissolved Oxygen (DO) Minimum mg/l DO Maximum mg/l Fecal Coliform (FC) Bacteria Daily Maximum FC Bacteria Monthly Average FC/100 milliliters (FC/100mL) 2, ,000 49,079 FC/100mL 1,300-62,800 11,717 Flow- Daily Maximum MGD Flow- Monthly Average MGD ph Maximum Standard Units (SU) ph Minimum SU Temperature Degrees Celsius ( C) Total Suspended Solids (TSS) Daily Maximum mg/l TSS Monthly Average mg/l TSS Weekly Average mg/l TSS Percent Removal % Page 7 of 58

8 2.1 Permit Background The facility was originally permitted by the Environmental Protection Agency (EPA) in The city applied for a waiver from secondary treatment standards per Section 301(h) of the Clean Water Act (CWA) in 1980 that was granted in The city subsequently requested to rescind the 301(h) waiver in 1987 and opted to continue operations as a secondary treatment plant. EPA issued the most recent National Pollutant Discharge Elimination System (NPDES) permit (AK ) to the City of Kodiak on July 22, This permit was administratively extended. The city submitted application Form 2M requesting a mixing zone to DEC on March 7, 2016 and an updated application Form 2A on September 2, The discharge permit history is summarized in Table 2. Table 2: Discharge Permit History Date 10/29/1974 Permit Action EPA issued initial NPDES permit. Permit contained compliance schedule to achieve secondary treatment standards as it was not operating as designed. Permit expired April 30, Facility placed into service 9/13/1978 City requested waiver from EPA from secondary treatment standards under Section 301(h) of CWA 1/3/1983 EPA deemed 301(h) waiver application complete 5/31/1985 EPA granted 301(h) waiver, reissued permit with an expiration date of July 2, /17/1987 EPA received application to rescind 301(h) waiver and modify permit 3/11/1988 EPA modified permit; added FC bacteria effluent limits and ambient monitoring requirements, prohibited the use of chlorine disinfection (unless necessary to meet FC bacteria effluent limits which were 500,000 FC/100 ml monthly average and 1,000,000 FC/100 ml daily maximum), increased BOD5 and TSS load limits, decreased BOD5 and TSS percent removal requirement from 85% to 75%, and lowered ph maximum limits from 9.0 to 8.5 SU. Permit expired April 12, /24/1994 EPA received application for NPDES permit re-issuance 9/3/1998 EPA requested an updated permit application for permit re-issuance 10/19/1998 EPA received permit application for permit re-issuance 7/22/1999 EPA reissued NPDES permit AK , effective August 24, 1999 and expired August 25, Reduced FC bacteria effluent limits to monthly average of 200,000 FC/100 ml, daily maximum to 500,000 FC/100 ml. Increased BOD5 and TSS effluent loading limits. Implemented 4.7 MGD monthly average and 6.2 MGD daily maximum effluent flow limits and DO and total residual chlorine (TRC) limits added. 3/21/2004 EPA received NPDES permit application for permit reissuance 1/29/2008 DEC received copy of March 2004 NPDES permit application for permit reissuance 10/31/2008 DEC granted primacy/authority to issue APDES permits 4/23/2013 DEC requested an updated permit application with legally required expanded effluent and whole effluent toxicity (WET) sample results for permit reissuance 2016 City of Kodiak submits Mixing Zone Application Form 2M in March 2016 and Application Form 2A to DEC in September Page 8 of 58

9 3.0 COMPLIANCE HISTORY DEC reviewed Discharge Monitoring Reports (DMRs) from June 2012 to June 2017 to determine the facility s compliance with permit effluent limits. The facility is in compliance with the permit effluent limits, with only one permit effluent limit violation occurring in the most recent five years of operation. In December 2014, the facility violated the daily maximum flow limit of 6.2 MGD with a daily maximum flow of 7.0 MGD due to heavy rainfall. While reviewing DMR data during permit development, the Department discovered instances where the City of Kodiak s DMR data for BOD5 and TSS percent removal was incorrectly reported. None of the reporting errors resulted in permit effluent limit violations. DEC informed the City of Kodiak of the existence of the errors and provided compliance assistance in correcting the reporting errors going forward. The City s DMRs are submitted on a timely and consistent basis. DEC inspected the City of Kodiak WWTF in 2012, 2014 and All inspections resulted in reports of no violations observed at the facility. 4.0 EFFLUENT LIMITS AND MONITORING REQUIREMENTS 4.1 Basis for Permit Effluent Limits The CWA requires that the limits for a particular pollutant be the more stringent of either technologybased effluent limits (TBELs) or water quality-based effluent limits (WQBELs). TBELs are set according to the level of treatment that is achievable using available technology. A WQBEL is designed to ensure that the water quality standards (WQS) of a water body are met. WQBELs may be more stringent than TBELs. The permit contains a combination of both TBELs and WQBELs. The Department first determines if TBELs are required to be incorporated into the permit. TBELs for publicly owned treatment works (POTW), which apply to the publicly owned WWTP, are derived from the secondary treatment standards found in Title 40 Code of Federal Regulations (40 CFR) and 40 CFR , adopted by reference at 18 AAC (e). A more expansive technical and legal basis for the proposed effluent limits is provided in APPENDIX B. 4.2 Basis for Effluent and Receiving Water Monitoring In accordance with AS (d), the Department may specify in a permit the terms and conditions under which waste material may be disposed. Monitoring in a permit is required to determine compliance with effluent limits. Monitoring may also be required to gather effluent and receiving water data to determine if additional effluent limits are required and/or to monitor effluent impact on the receiving water body quality. The permit also requires the permittee to perform effluent monitoring required by the APDES Form 2A application, so that this data will be available when the permittee applies to reissue its APDES permit. The permittee is responsible for conducting the monitoring and reporting results in the application for reissuance to the Department. 4.3 Pollutants of Concern Pollutants of concern known to be present in the effluent of the City of Kodiak WWTF consist of domestic wastewater conventional pollutants regulated in TBELs via the secondary treatment standards, which include BOD5, TSS, and ph. Additional domestic wastewater pollutants such as temperature, DO, ammonia, enterococci and FC bacteria are known to be present in the discharge. As the City of Kodiak WWTF has a design flow larger than 1.0 MGD, WET is a pollutant of concern as required under 18 AAC (b)(1). More information about WET requirements can be found in Fact Sheet Section 4.5. TRC is a potential pollutant of concern should the City of Kodiak choose to disinfect the effluent to Page 9 of 58

10 treat pathogens via chlorination. Expanded effluent test results for detected pollutants at the City of Kodiak WWTF are summarized in Table 3. These monitoring results demonstrate that copper is a pollutant of concern and requires additional effluent monitoring to more robustly analyze its prevalence and concentration in the effluent. 4.4 Influent and Effluent Limits and Monitoring Requirements The permit contains a combination of both TBELs and WQBELs. The following summarizes the proposed effluent limits (see Fact Sheet APPENDIX B - APPENDIX D for more details). The permit contains a new WQBEL for ammonia. Since 1999, the City of Kodiak WWTF has been monitoring and reporting ammonia effluent data on a monthly basis. The laboratory analysis of ammonia effluent samples was performed by the City of Kodiak in the WWTF laboratory. The most recent five years of ammonia effluent data (June June 2017) indicates that the discharge has reasonable potential (RP) to exceed the acute and chronic aquatic life marine water quality standards at the boundary of the mixing zone, therefore, an ammonia WQBEL has been included in the permit. The final acute and chronic mixing zones are driven by ammonia. During the reasonable potential analysis (RPA) conducted for ammonia, the Department discovered anomalies in how the City of Kodiak laboratory analyzed ammonia effluent samples. More information on these anomalies and assumptions that the Department made while examining the data as well as the basis for the effluent limits in the permit are provided in Fact Sheet APPENDIX B - APPENDIX D. The previous permit implemented a WQBEL for TRC because the facility had the ability to disinfect using chlorine, although it did not disinfect. A revised WQBEL for TRC is carried forward from the previous permit. TRC monitoring frequency is also carried forward from the previous permit - five times per week if the facility disinfects using chlorine. The Department opted not to carry forward the TRC effluent monitoring requirement of requiring an effluent TRC sample twice per month if the facility was not chlorinating. This is consistent with most other APDES permits for POTWs and domestic wastewater discharges. TRC monitoring is rarely required if a facility is not disinfecting and the pollutant is not otherwise expected to be present in the effluent. The TRC monitoring performed twice per month by the facility over the most recent five years confirms that there were no detected TRC effluent results above the method detection limit/compliance level of 0.05 mg/l implemented in the permit. Table 4 summarizes the changes made to effluent limits and monitoring requirements between the 1999 and current permit issuance. See Fact Sheet APPENDIX B, Section B for additional information on the TRC WQBEL. Expanded effluent test results for detected pollutants are summarized in Table 3. The aquatic life criteria for marine water for copper are 5.78 micrograms per liter (µg/l) acute and 3.73 µg/l chronic (total recoverable). Three expanded effluent test results indicate that copper was detected in the effluent in concentrations exceeding both acute and chronic aquatic life WQS numeric criteria. Consistent with the Department s RPA and Effluent Limitation Guidance, in situations such as this when less than ten valid data points exist for a pollutant on which to perform an RPA, the Department can include a requirement for the discharger to collect additional effluent data to produce a more robust data set. Accordingly, the permit implements a monthly copper monitoring requirement to characterize the presence and variability of copper in the effluent to more accurately evaluate RPA in the next permit issuance. This decision is appropriate given the low concentrations detected and the variability observed among the three existing copper effluent data points, which vary from µg/l. Zinc was detected in two of the three expanded effluent samples at concentrations that did not exceed the WQS numeric criteria. Nickel was detected in one of the three expanded effluent samples at a concentration that did not exceed WQS numeric criteria. Pollutants detected in the effluent for which marine WQS numeric criteria do not exist include chloroform (trichloromethane), calcium, Kjeldahl nitrogen, magnesium, total phosphorous, total Page 10 of 58

11 nitrate/nitrite, and total dissolved solids. Therefore, the permit does not require any additional monitoring for these pollutants beyond that already required in expanded effluent testing. Toluene was detected three times in the expanded effluent testing in concentrations of less than one percent of water quality standard numeric criteria for toluene, therefore the permit does not require additional toluene monitoring beyond that already required for expanded effluent testing. Table 3: Expanded Effluent Tests Detected Pollutants Pollutant August 2014 December 2014 April 2015 June 2015 Units Calcium Not Sampled (NS) mg/l Chloroform NS 3.4 µg/l Copper Hardness as CaCO 3 68 ND 66 mg/l Kjeldahl Nitrogen NS mg/l µg/l Magnesium mg/l Nickel ND ND 2.6 µg/l Toluene 0.6 a 2.2 NS 1.4 µg/l Total Dissolved Solids mg/l Total Nitrate/Nitrite mg/l NS Total Phosphorous 0.85 ND 0.77 mg/l Zinc ND µg/l Footnotes: a. Result was J-flagged as an estimation with a practical quantitation limit of 1.0 µg/l and a method detection limit of 0.3 µg/l. The permit requires monitoring of the effluent for BOD5, TSS, TRC, FC bacteria, enterococci bacteria, DO, ph, and ammonia to determine compliance with the permit TBELs and WQBELs. Temperature and enterococci bacteria monitoring of the effluent is required on a monthly basis, although enterococci effluent monitoring is only required during the months of May-September. Enterococci bacteria monitoring is required due to recent regulatory changes to recreational WQS for bacteria and to develop a dataset for enterococci on which to perform a RPA for the next permit reissuance. More information about enterococci can be found in Fact Sheet section B in APPENDIX B. Effluent temperature monitoring is carried forward from the previous permit and temperature is included in the chronic mixing zone. The permit also requires monitoring of the influent for BOD5 and TSS to calculate monthly removal rates for these parameters. The frequency of monitoring for BOD5, TSS, FC bacteria and DO changed from the previous permit. BOD5 and TSS effluent monitoring was increased from four times per month to once per week to mirror the requirements for the majority of other POTWs in the state of Alaska and to be consistent with recommended monitoring frequencies based on POTW design flows in DEC s RPA and Effluent Limits Development Guide. This change is appropriate and will aid in assessing compliance with the permit s new minimum BOD5 and TSS percent removal requirements. FC bacteria monitoring frequency was also slightly increased from four times per month to once per week to more thoroughly monitor FC bacteria and assess compliance with the FC bacteria compliance schedule. DO monitoring frequency was increased from twice per month to once per week to mirror frequency of DO requirements of similarly sized POTWs. More frequent DO monitoring is appropriate as this parameter is variable and this will allow the Department more information to determine compliance with the new, more stringent WQBEL for DO. Page 11 of 58

12 The permit requires effluent sampling for WET as well to determine what if any chronic toxicity the discharge has at various concentrations of effluent. Required test species have changed as has the dilution series, accelerated testing trigger value, and frequency of WET testing. See Fact Sheet Section 4.5 for further discussion of WET requirements. Changes of permit effluent limits and monitoring requirements from the previous permit are summarized in Table 4. Table 4: Effluent Monitoring and Limit Changes from Prior Permit Parameter Units Average Monthly Limit 1999 Permit Current Permit Average Weekly Limit 1999 Permit Current Permit Maximum Daily Limit 1999 Permit Current Permit Sample Frequency 1999 Permit Current Permit BOD 5 Loading TSS Loading BOD 5 & TSS % Removal Total Ammonia as Nitrogen Pounds per day (lbs/day) 1, ,800 1,200 3,100 1,600 4/Month 1/Week % N/A N/A Monthly mg/l N/A 9.39 N/A Report Monthly Copper µg/l N/A 3/5 Years 1/Month WET a TU c N/A 3/4 Years 1/Year Enterococci Bacteria cfu/ 100 ml b TRC mg/l N/A c N/A c N/A DO mg/l N/A FC Bacteria (Final) FC/ 100 ml N/A Min 2 Max 17 Min 6 Max 17 5/Week or 2/Month 2/Month Monthly May - September 5/Week if Chlorinating Page 12 of 58 1/Week 200, N/A , /Month 1/Week Footnotes: a. Changes have also occurred to required species and dilution series. See Fact Sheet section 4.5 for additional information. b. cfu/100 ml = colony forming unit per 100 milliliters. c. DEC shall use 0.05 mg/l as the compliance limit for this parameter. See Fact Sheet APPENDIX B, section B for additional information. The previous permit implemented 75% BOD5 and TSS monthly average percent removal requirements via a special consideration granted by EPA in 1999 at the request of the City. This request was granted via special consideration regulations at 40 CFR The City did not request this consideration in the current permit application. The Department also reviewed the most recent five years of WWTF BOD5 and TSS effluent data and concluded the special consideration can no longer be granted. Accordingly, the permit implements the secondary treatment standards with a 30 day average percent removal of 85% for BOD5 and TSS. Additional analysis is provided in Fact Sheet APPENDIX B, section B.1 TSS and BOD5 effluent loading limits were re-calculated consistent with regulations at 18 AAC (a), which indicate that for POTWs such as the City of Kodiak WWTF, permit effluent limits shall be calculated based on design flow. A review of the effluent BOD5 and TSS loading data

13 from June 2012 June 2017 indicate the facility is not likely to have an issue meeting the more stringent effluent loading limits. Monitoring frequencies are based on the nature and effect of the pollutant, as well as a determination of the minimum sampling necessary to adequately monitor the facility s performance. The permittee has the option of taking more frequent samples than required under the permit. These additional samples can be used for averaging (for pollutants results reported on a monthly or weekly average) if they are conducted using the Department approved test methods (generally found in 18 AAC 70 and 40 CFR Part 136 [adopted by reference in 18 AAC ]), and if the Method Detection Limits (MDLs) are less than the effluent limitations and sufficiently sensitive. Table 5 presents the influent and effluent monitoring and limit requirements. Page 13 of 58

14 Parameter Table 5: Influent and Effluent Limits and Monitoring Requirements Daily Minimum Monthly Average Effluent Limits Weekly Average Daily Maximum Units a Sample Location Monitoring Requirements Sample Frequency Sample Type Total Discharge Flow N/A 4.7 N/A 6.2 mgd Effluent Continuous Recorded Biochemical Oxygen mg/l Influent and 24-hour N/A 1/Week Demand (BOD 5) 800 1,200 1,600 lbs/day b Effluent Composite c Total Suspended Solids mg/l Influent and 24-hour N/A 1/Week (TSS) 800 1,200 1,600 lbs/day Effluent Composite BOD 5 & TSS Minimum Percent (%) Removal Fecal Coliform (FC) Bacteria 85 % N/A 200 e 400 e 800 FC / 100 ml Influent and Effluent 1/Month Calculated d Effluent 1/Week Grab ph 6.5 N/A 8.5 SU Effluent 5/Week Grab Dissolved Oxygen 6.0 N/A 17.0 mg/l Effluent 1/Week Grab Temperature N/A Report C Effluent 5/Week Grab Total Ammonia, as N N/A mg/l 24-hour N/A Effluent 1/Month lbs/day Composite Enterococci Bacteria N/A Report Whole Effluent Toxicity cfu / 100 ml Effluent 1/Month (May-Sept) f N/A Report TU c Effluent 1/Year g Copper g N/A Report µg/l Effluent 1/Month Grab 24-hour Composite 24-hour Composite Total Residual Chlorine N/A (TRC) h N/A h mg/l Effluent 5/week i Grab Footnotes: a. Units: mgd = million gallons per day, mg/l = milligrams per liter, lbs/day = pounds per day, cfu/100 ml = colony forming units per 100 milliliters, FC/100 ml = fecal coliform per 100 milliliters, SU= standard units, C= degrees Celsius, TUc = toxic units, chronic, and µg/l = micrograms per liter. b. All loading limits calculated using design flow of 3.2 MGD. Loading in lbs/day = [(design flow in million gallons per day (mgd)) x (concentration in mg/l) x 8.34]. c. Composite samples must consist of at least eight grab samples collected at equally spaced intervals and proportionate to flow so that composite samples reflect influent/effluent quality during the compositing period. d. Minimum percent removal = [(average monthly influent concentration in mg/l average monthly effluent concentration in mg/l) / (average monthly influent concentration in mg/l)] x 100. The monthly average percent removal must be calculated using the arithmetic mean of the influent value and the arithmetic mean of the effluent value for that month. Calculation required monthly e. If more than one FC bacteria sample is collected within a 30-day (monthly) or 7-day (weekly) period, the average result must be reported as the geometric mean. When calculating the geometric mean, replace all results of zero, 0, with a one, 1. The geometric mean of n quantities is the nth root of the product of the quantities. For example the geometric mean of 100, 200, and 300 is (100 X 200 X 300) 1/3 = See Permit APPENDIX C for calculation. f. One enterococci bacteria sample shall be collected each month, May through September, on the same day as the FC bacteria sample is collected. g. All metals shall be reported as total recoverable. h. Effluent limits for total residual chlorine are not quantifiable using EPA-approved analytical methods. The permittee will be in compliance with the effluent limits provided the TRC levels are below the compliance evaluation level of 0.05 mg/l. i. If the facility disinfects with chlorine, TRC monitoring frequency is five times per week. If the facility does not chlorinate, TRC sampling is not required. Page 14 of 58

15 4.4.1 Additional Monitoring The previous permit contained a facility planning requirement whereby the permittee was required, on a monthly basis, to calculate an annual average monthly flow, influent BOD5 loading, and influent TSS loading based on the previous 12 months of data. The permittee was instructed to report the results on the monthly DMR in the comments section. The permittee was to compare these annual averages to the design criteria listed in the permit and if the annual average value exceeded 85% of the design criteria, the facility would be required to develop a facility plan and upgrade schedule within one year of the date of the exceedance of the threshold value. A review of the most recent five years of DMRs submitted by the City concluded that if these values were calculated on a monthly basis as the previous permit required, they were not submitted in the comments section of the monthly DMRs. The Department examined the most recent (June June 2017) annual average values in relation to the facility planning thresholds and determined that none of the design criteria (or 85% of the design criteria) were violated and no facility plan or upgrade is necessary at this time based on this requirement. The Department is carrying the planning requirement forward but will require this information to be submitted with the application for permit reissuance as opposed to the DMR. The permittee shall perform the additional effluent testing in the APDES application Form 2A for POTWs. The permittee shall submit the results of this additional testing with their application for renewal of this APDES permit. The permittee shall consult and review Form 2A upon permit issuance to ensure that the required monitoring in the application will be completed prior to submitting a request for permit renewal. A copy of Form 2A can be at: Whole Effluent Toxicity Monitoring 18 AAC requires that a permit contain limitations on WET when a discharge has reasonable potential to cause or contribute to an exceedance of a WQS. WET tests use small vertebrate and invertebrate species to measure the aggregate toxicity of an effluent. Chronic toxicity tests measure reductions in survival, growth, and reproduction over a two (bivalve) or seven (topsmelt) day exposure. WET testing is included in the permit to demonstrate any potential toxicity resulting from the WWTF discharge. The previous permit required the permittee to perform vertebrate testing on topsmelt Atherinops affinis and invertebrate testing of either Mysidopsis bahia, Crassostrea gigas, Strongylocentrotus purpuratus, or Dendraster excentricus. The previous permit s WET requirements were to conduct two tests between June 1, 2000 and December 31, 2000 and two tests in The Department advised the City to perform four quarterly WET tests to submit with their application Form 2A, per 18 AAC 335(d) which states a minimum of four quarterly WET tests for a year from the year preceding the permit application. The City submitted four quarterly WET tests for vertebrate species and three quarterly WET tests for invertebrates. The City did not submit the WET data in a timely fashion, as the WET data was collected September June 2015 and submitted application Form 2A in September 2016; thus was not from the year preceding the September 2016 permit application. The WET tests were performed on the vertebrate inland silverside Menidia beryllina and invertebrate mussel Mytilius galloprovincialis with a dilution series of 4, 2, 1.16, 0.5, 0.2 and 0 (control) % effluent. The previous permit indicated the WET receiving water concentration (RWC) (and WET accelerated testing trigger value) was 86 chronic toxic units (TUc), which corresponds to a critical dilution of 1.16% effluent (100/86 TUc = 1.16%). The 86 TUc RWC appeared to be the result of including WET in the ZID in the State of Alaska 401 Certificate of Reasonable Assurance for the previous permit. The ZID was defined as 30 meters wide and authorized a dilution factor of 86:1. More information on the ZID can be found in Fact Sheet Section The seven WET test results submitted to the Department with the City s application all reported a No Observed Effects Concentration (NOEC) of 4% effluent, which was the highest concentration of effluent tested. All WET tests reported an NOEC of 25 TUc. The Department will continue to include WET in Page 15 of 58

16 the chronic mixing zone, which is driven by ammonia and provides a dilution of 18.5:1. This dilution results in a WET RWC of 5.4% (100/18.5 = 5.4). The dilution series for WET testing was determined consistent with guidance specified in Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to West Coast Marine and Estuarine Organisms, West Coast Methods, EPA/600/R-95/136, August The West Coast Methods recommend that RWC of < 25% effluent have a dilution series of the RWC bracketed by: 1) four times the RWC (5.4*4=21.6%), 2) two times the RWC (5.4*2=10.8%), 3) RWC/2 (5.4/2=2.7%), and 4) RWC/4 (5.4/4=1.4%). Accordingly, the dilution series implemented in the permit is 21.6%, 10.8%, 5.4%, 2.7%, and 1.4% effluent and a control. The permittee must conduct short-term chronic tests with a bivalve species (larval development test), either the Pacific oyster (Crassostrea gigas) or the mussel (Mytilus galloprovincialis) and with the topsmelt (Atherinops affinis). The topsmelt was selected as fish are more sensitive to ammonia, and ammonia is now understood to be a pollutant of concern that drives the acute mixing zone. The presence of chronic toxicity must be determined as specified in the West Coast Methods. WET tests will be required once per year. The permit continues to include a toxicity trigger, which is a threshold level for WET, specified in TUc, used to trigger accelerated WET monitoring when there is no reasonable potential for WET and no WET WQBEL. The permit requires accelerated WET testing if toxicity is greater than the trigger of 18.5 TUc in any test TUc was chosen as TUc is defined in 18 AAC (b) as the expression of chronic toxicity in an effluent, determined as (100/NOEC) where the NOEC is the highest percentage concentration of an effluent tested that causes no observable adverse effects. The RWC of 5.4% effluent corresponds to an expectation that toxicity in excess of 18.5 TUc (100/5.4 = 18.5) would exceed the expected RWC of 5.4% effluent at the boundary of the authorized chronic mixing zone. In addition to an accelerated testing trigger, the permit requires that if the permittee demonstrates through an evaluation of facility operations that the cause of an exceedance of the accelerated testing trigger is known and corrective actions have been implemented, only one accelerated test is necessary. If the cause of the exceedance isn t known, two more bi-weekly WET tests shall be conducted over a four week period. While the previous permit required more accelerated testing (six WET tests as opposed to two) in the event of an exceedance of the previous WET trigger value, it required less frequent WET tests overall (three during the five year permit term). Based on the current information, the known presence of toxic pollutants such as ammonia and copper make the increase in regular WET testing (five during the five year permit term) appropriate. If toxicity is greater than 18.5 TUc in any accelerated tests, the permittees must initiate a Toxicity Reduction Evaluation (TRE). A TRE is required so that the specific cause of the toxicity can be identified and mitigated (see Permit Section for further details). If a TRE is initiated, a toxicity identification evaluation (TIE) may also be initiated and must be performed in accordance with EPA guidance manuals, Toxicity Identification Evaluation: Characterization of Chronically Toxic Effluents, Phase I (EPA/600/6-91/005F, 1992); Methods for Aquatic Toxicity Identification Evaluations, and Phase II Toxicity Identification Procedures for Samples Exhibiting Acute and Chronic Toxicity (EPA/600R-92/080, 1993). TRE and TIE requirements were included in the previous permit as well. 4.6 Receiving Water Body Limits and Monitoring Requirements The previous permit required the City to monitor for FC bacteria, temperature, and ph at the boundaries of the mixing zone at the shoreline near the facility and at the boundaries of the 3,200 by 400 meter mixing zone in Woody Island Channel on the north, east and south ends. The receiving water monitoring was required on a monthly basis during the months of May, July and August, and a quarterly basis during the months October-March. The City has consistently collected this data and the monitoring results collected June June 2017 are summarized in Table 6. FC bacteria receiving water and shoreline monitoring could detect FC bacteria originating from any point or nonpoint source of FC bacteria, including sources other than the WWTF. Additionally, mixing zone modelling indicates that Page 16 of 58

17 due to density stratification in the receiving water, it s unlikely that the effluent plume reaches the surface of the receiving water where the previous ambient FC bacteria monitoring occurred. The Department is implementing a compliance schedule in the permit for FC bacteria that ultimately requires disinfection of the effluent, which will significantly reduce the count of FC bacteria discharged. The permit no long requires ambient monitoring for FC bacteria. Because the final mixing zone has significantly decreased in size, the Department is requiring receiving water monitoring in one location outside of the influence of the mixing zone for ph, temperature and salinity to inform the calculation of the appropriate ammonia WQ criterion, as well as for ammonia and copper to inform the ambient concentration of those pollutants in the RPA for the next permit issuance. Receiving water monitoring permit requirements are presented in Table 7. The permittee must seek written approval of the receiving water monitoring station from DEC prior to commencing receiving water monitoring within 180 days of the effective date of the permit. The monitoring will be required two times per year during the months of October-May, which is the critical season for determining the most protective ammonia WQS numeric criteria. One sample must be taken in the months of May - July and one sample in the months of August October. Receiving water monitoring results must be submitted to DEC as an attachment to the edmr for the month following sample collection. Table 6: Analytical Results Shoreline and Mixing Zone Boundary Sample Location Minimum Value in FC/100mL Maximum Value in FC/100mL Average ph in SU Average Temperature in C Shoreline < North < East < South < Note: This table summarizes the results of 27 mixing zone boundary and shoreline analytical results from each of the four sample locations. However, over 60% of the FC bacteria samples from the North, South and East locations were non-detects. Table 7: Receiving Water Monitoring Requirements Parameter a Units Frequency Sample Type Ammonia Copper ph Salinity mg/l µg/l SU ppt Temperature C Two Samples (May-October) b Footnotes: a. The permittee must use a sufficiently sensitive Environmental Protection Agency (EPA) approved test method that quantifies the level of pollutants to a level lower than applicable limits or water quality standards or use the most sensitive Title 40 Code of Federal Regulations (CFR) Part 136 (Guidelines Establishing Test Procedures for the Analysis of Pollutants), adopted by reference at 18 AAC (f) test method available. b. Two samples (May-October) means one sample must be taken in the months of May - July and one sample in the months of August October. Grab Page 17 of 58

18 5.0 RECEIVING WATER BODY Diffuser Section One Two Three 5.1 Description of Receiving Water Body Woody Island Channel lies within Chiniak Bay, in the northeastern Kodiak Island shoreline between Woody Island and the island of Kodiak. Woody Island Channel is bounded to the northwest by the island of Kodiak, to the southwest by multiple islands, including Near Island, and to the south by Woody Island. The distance between Kodiak Island and Woody Island at the City of Kodiak WWTF outfall is approximately 1,167 meters (3,829 feet). Water depths in Woody Island Channel can reach up to 45.7 meters (150 feet) below mean lower low water (MLLW). The approximate flood direction of the tide in the area of the WWTF outfall is 60 degrees true. The bottom of Woody Island Channel is composed of a variety of materials including bedrock, boulders, cobbles, gravel and sand. 5.2 Outfall Location The treated effluent from the City of Kodiak WWTF is discharged at North latitude and West longitude, to Woody Island Channel. The outfall to Woody Island Channel extends approximately 274 meters (900 feet) from shore. The 38.1 meter (125 foot) long outfall diffuser has three distinct sections, each containing different pipe diameters, riser and port configurations, and port diameters. The beginning of the 38.1 meter long outfall diffuser is situated at a depth of approximately meters (22.5 feet) below MLLW. The terminus of the 38.1 meter long diffuser occurs at a depth of approximately -9.1 meters (30 feet) below MLLW. The diffuser configuration is summarized in Table 8. Risers are 0.25 meters (10 inches) tall and spaced 6.1 meters (20 feet) apart, except the final riser, which is 7.6 meters (25 feet) away from the riser preceding it. Length of Section 18.3 meters (60 feet) 12.2 meters (40 feet) 7.62 meters (25 feet) Diffuser Diameter 0.45 meters (18 inches) 0.4 meters (16 inches) 0.36 meters (14 inches) Table 8: Diffuser Configuration Number of Risers Riser Configuration Number of Ports per Riser Four T-type Two Two One T-type and one single port T-type has two, single port has one Diameter of Ports 0.10 meters (four inches) Single Port is 0.10 meters, T-type is meters (five inches) Two T-type Two meters 5.3 Water Quality Standards Regulations in 18 AAC 70 require that the conditions in permits ensure compliance with the WQS. The state s WQS are composed of use classifications, numeric and/or narrative water quality criteria, and an antidegradation policy. The use classification system identifies the designated uses that each water body is expected to achieve. The numeric and/or narrative water quality criteria are the criteria deemed necessary by the state to support the designated use classification of each water body. The antidegradation policy ensures that the existing uses and the level of water quality necessary to protect the uses are maintained and protected. Water bodies in Alaska are designated for all uses unless the water has been reclassified under 18 AAC as listed under 18 AAC (e). Some water bodies in Alaska can also have site specific water quality criterion per 18 AAC , such as those listed under 18 AAC (b). The receiving water for the discharge, Woody Island Channel, has not been reclassified, nor have sitespecific water quality criteria been established. Therefore, Woody Island Channel must be protected for Page 18 of 58

19 all marine water use classes listed in 18 AAC (a)(2). These marine water designated use classes consist of the following: water supply for aquaculture, seafood processing and industrial; water recreation for contact and secondary recreation; growth and propagation of fish, shellfish, other aquatic life, and wildlife; and harvesting for consumption of raw mollusks or other raw aquatic life. 5.4 Water Quality Status of Receiving Water Any part of a water body for which the water quality does not or is not expected to meet applicable WQS is defined as a water quality limited segment and placed on the state s impaired water body list. For an impaired waterbody, Section 303(d) of the CWA requires states to develop a Total Maximum Daily Load (TMDL) management plan for a water body determined to be water quality limited. The TMDL documents the amount of a pollutant a water body can assimilate without violating a state s WQS and allocates that load to known point sources and nonpoint sources. Woody Island Channel is not included on the Alaska s Final 2010 Integrated Water Quality Monitoring and Assessment Report, July 15, 2010, as an impaired water body, nor is the water body listed as a CWA 303(d) Water body, subject to a pending or approved TMDL. 5.5 Mixing Zone Analysis In accordance with state regulations at 18 AAC , as amended through June 26, 2003, the Department may authorize a mixing zone in a permit. A chronic mixing zone is sized to protect the ecology of the waterbody as a whole and an acute mixing zone is sized to prevent lethality to passing organisms. The State of Alaska 401 Certificate of Reasonable Assurance for the 1999 NPDES permit issued to the City authorized a rectangular, 3,200 meter long by 400 meter wide (1,600 meter long by 400 meter wide on either side of the outfall) mixing zone for FC bacteria extending from the marine bottom to the surface and running parallel to shore. In addition to authorizing a FC bacteria mixing zone, the State Certificate of Reasonable Assurance authorized a circular zone of initial dilution (ZID) with a 30 meter radius, centered over the outfall line extending from the marine bottom to the surface. The ZID provided a dilution factor of 86 for DO, ph, TRC, metals, nutrients and WET. Until the City is in compliance with the permit s final FC bacteria effluent limits, the FC bacteria mixing zone authorized in the previous permit will remain in effect. Once compliance with final FC bacteria effluent limits is achieved, the acute and chronic mixing zones driven by ammonia will be authorized as described in this Fact Sheet Section. Permit Sections through also describe the sizes of the revised acute and chronic mixing zones. Information on the previous FC bacteria mixing zone is located in the State of Alaska DEC 401 Certificate of Reasonable Assurance issued July 9, All other mixing zone parameters (FC bacteria, WET, and temperature) are authorized as described in this Fact Sheet section. The permittee submitted a mixing zone application in March 2016 requesting re-authorization of the previously authorized mixing zone for FC bacteria, with a proposed modification of the 400 meter width. The permittee proposed a meter FC bacteria mixing zone width as 200 meters wide at the diffuser expanding to 300 meters wide at the boundary of the mixing zone. The permittee stated that making the mixing zone 200 meters wide at the diffuser would make the mixing zone width less than 10% of the cross sectional width of Woody Island Channel, which they stated complied with mixing zone regulations regulating cross sectional width of mixing zones in 18 AAC (e)(1)(A). DEC modeled the acute and chronic mixing zones and calculated dilution factors using the Cornell Mixing Zone Expert System (CORMIX) version 10.0 modeling program, which yielded different mixing zone sizes than proposed by the applicant as described in the preceding paragraph and was based on effluent performance data from the WWTF s discharge. CORMIX 10.0 is the latest version of the widely used and broadly accepted modeling tool for accurate and reliable point source mixing analysis. Page 19 of 58

20 Inputs to CORMIX included the maximum expected effluent concentration and the acute and chronic WQS numeric criteria of parameters, such as ammonia, that demonstrated reasonable potential (RP) (see APPENDIX B for details on the RPA) to exceed water quality criteria at the end of pipe prior to discharge, as well as site-specific discharge and ambient data such as varying tidal velocities that simulate the alternating currents associated with the flow and ebb of tides in Woody Island Channel. Ammonia required the most dilution to reach acute and chronic water quality (WQ) criteria, therefore, ammonia determined the final acute and chronic mixing zone size. Temperature, WET, and FC bacteria fit within the chronic mixing zone sized for ammonia. The WQ criteria for ammonia, WET, FC bacteria and temperature may be exceeded within the authorized chronic ammonia mixing zone. The chronic ammonia mixing zone for the subject discharge has a dilution factor of 18.5 and is defined as a rectangle, with a length, parallel to the shore, of 49.6 meters and a width of meters. The mixing zone extends from the seafloor to the surface. All numeric WQ criteria will be met and apply at the boundary of the chronic mixing zone. There is a smaller, initial, acute mixing zone for ammonia surrounding the outfall and contained within the larger chronic mixing zone. The acute mixing zone for this discharge has a dilution factor of 2.45 and is defined as a rectangle, with a length of 0.15 meters and a width of 0.44 meters. Acute aquatic life criteria for ammonia will be met and apply at and beyond the boundary of this smaller initial mixing zone surrounding the outfall. According to EPA (1991) and 18 AAC , lethality to passing organisms would not be expected if an organism passing through the plume along the path of maximum exposure is not exposed to concentrations exceeding the acute criteria when averaged over a one hour time period. Furthermore, the travel time of an organism drifting through the acute mixing zone must be less than approximately 15 minutes if a one hour exposure is not to exceed the acute criterion. The Department determined that the travel time of an organism drifting through the acute mixing zone to be approximately 1.7 seconds; therefore, there will be no lethality to organisms passing through the acute mixing zone. Other data required for the mixing zone modeling included: the input of receiving water characteristics at the outfall such as the depth the receiving water at the outfall, the ambient velocity, wind velocity, and outfall and diffuser specifications, such as the size, direction, and number of ports. Based on the inputs, CORMIX predicted the distance at which the parameters would meet WQ criteria as well as the corresponding dilution at that point. APPENDIX E outlines criteria that must be met in order for the Department to authorize a mixing zone. These criteria include the size of the mixing zone, treatment technology, existing uses of the waterbody, human consumption, spawning areas, human health, aquatic life, and endangered species. The following summarizes the Department s mixing zone analysis: Size In accordance with 18 AAC , the mixing zone must be as small as practicable. In order to ensure that the mixing zone is as small as practicable, DEC used CORMIX to model the chronic and acute mixing zones at various critical tidal velocities, effluent temperatures, effluent flow rates and ambient density profiles. 18 AAC (b)(5) requires the Department to consider the characteristics of the effluent after treatment of the wastewater. DEC reviewed the most recent five years of DMRs from June 2012 through June 2017 and the City s wastewater discharge application, Form 2A, to determine which parameters had RP to exceed WQ criteria at the end of pipe, and then which of the parameters required the most dilution to meet WQ criteria for the chronic and acute mixing zones. Ammonia is the only pollutant that requires dilution in the acute mixing zone and therefore is the driving parameter. Ammonia also required the most dilution in the chronic mixing zone to meet chronic aquatic life WQ criteria. Ammonia was modeled in CORMIX to determine the smallest practicable acute and chronic mixing zone size. Page 20 of 58

21 The maximum expected concentrations for ammonia, corresponding ammonia WQ criteria, and assumed ambient ammonia concentrations were entered into CORMIX. For the ambient concentration of ammonia, the Department followed its RPA and Effluent Limit Development Guide, which stipulates when no ambient data exists, the permit writer shall assume that the ambient concentration of the pollutant is 15% of the most stringent applicable water quality criterion. Accordingly, an assumed ambient concentration of mg/l of ammonia was used as it represents 15% of the acute ammonia numeric WQ criteria (1.2 mg/l *.15 = mg/l). The ammonia WQ criterion and other mixing zone modelling parameters used in the modelling are depicted in Table 9 and the selection of the WQS criteria is described in Fact Sheet APPENDIX B Section B DEC consulted with MixZon Inc., the proprietors of the CORMIX mixing zone modeling software, regarding the City s unique diffuser configuration and how to most accurately, yet conservatively, accommodate the diffuser design. CORMIX assumes uniform discharge conditions along the diffuser line. A number of diffuser geometry parameters are not uniform along the diffuser line. For example, the diffuser diameter is not uniform along the entire length of the diffuser line. The Department modelled a single diffuser diameter of 18 inches for the entire length of the diffuser as only one diffuser diameter can be modelled. In reality, the diffuser contains shorter sections of 16 and 14 inch diameter which provide slightly more dilution of the wastewater prior to discharge than the 18 inch diameter pipe. The uniform 18 inch diameter assumption is a conservative assumption and was also the assumption presented by the permittee in their mixing zone application. CORMIX staff confirmed that the Department s approach to the diffuser was the most accurate yet conservative approach possible. The Department approached selecting a single diffuser port diameter to model similarly, as only a single diffuser port diameter can be modelled. Adopting the permittee s proposed approach, a port diameter of 4.3 inches (0.11 meters) was used, which is an average port diameter that includes the four five inch diameter ports and the nine four inch diameter ports. This is consistent with CORMIX User Manual guidance that mean values should be specified for variable diffuser geometry. One of the seven total diffuser risers contains one port instead of two ports, CORMIX cannot accommodate this variable design, so seven diffuser risers with two ports per riser for a total of 14 diffuser ports were modelled instead of the 13 diffuser ports that exist. The first six risers are spaced equally 20 feet from each other, while the final, seventh riser is spaced 25 feet from the riser that precedes it. A uniform riser/port spacing of 20 feet was assumed in the final model. This was also the assumption the permittee submitted in their mixing zone application. As mentioned earlier in this section, the permittee submitted a mixing zone application in March of 2016 requesting re-authorization with slight modification of the previously authorized 3,200 meter long meter wide mixing zone driven by FC bacteria. The mixing zone application described eight mixing zone model scenarios. Four scenarios explored dry season conditions, which the permittee defined based on precipitation records as occurring during the months March through August. The permittee varied their version of the 10 th and 50 th percentile ambient currents, the minimum and maximum density stratifications available via salinity profiles for the receiving water, and varied the effluent temperature and effluent flow. Effluent flow used in these scenarios were the maximum and average effluent flows that occurred during the dry season. The other four mixing zone scenarios examined a wet season, which the permittee defined based on precipitation records as occurring during the months of September through February. Similar to the dry season model scenarios, the permittee varied effluent temperature and effluent flow for both density stratifications at their version of the 10 th and 50 th percentile currents. The permittee modelled these eight mixing zone scenarios using Visual Plumes, a modelling software that is no longer supported on Windows operating systems newer than Windows XP. The State of Alaska is required to use computers with operating systems at least as new as Windows 7, therefore the Department does not have access to Visual Plumes. Visual Plumes, similar to CORMIX, was also not able to directly accommodate the diffuser design. The permittee examined two different approximations of the diffuser design in Visual Plumes and chose one to move forward with that approximated the Page 21 of 58

22 diffuser as consisting of thirteen single port risers spaced ten feet apart. When the Department attempted to mirror this diffuser design in CORMIX, the program would not accommodate the design because the angle of the port nozzles relative to the ambient current. CORMIX reported that in that configuration, the discharge momentum opposes the ambient current flow leading to complicated recirculation patterns and concentration build ups in the near field and would not continue the model. The permittee s mixing zone application presented 10 th and 50 th percentile ambient currents based off of a 1971 Oceanographic Investigation Relating to Sewage Outfall Site Selection at Kodiak, Alaska conducted by Tryck Nyman Hayes (TNH). The permittee did not include the study/data with their application, nor could the Department otherwise locate the TNH study/data. The TNH study involved deploying a current meter station for four days in April and May in 1971 in the center of Woody Island channel approximately 2,000 feet west of the outfall terminus. Approximately 25 hours of current measurements were collected from an anchored vessel at 10, 50, 100 and 150 foot depths (3.05, 15.2, 30.5, and 45.7 meters respectively) for a period of five minutes each hour. The permittee used only data from the 10 and 50 foot depth. This resulted in a 10 th percentile current of 3.1 centimeters per second (cm/s), a 50 th percentile current of 17.8 cm/s and a 90 th percentile current of 44.2 cm/s. Because the permittee felt the dataset from the 1971 study was limited, they chose to use software to predict tidal currents based off of tides in Kodiak Harbor (Chiniak Bay) to compare to the 1971 study. The softwarepredicted tidal currents resulted in a 10 th percentile current of 8.8 cm/s and a 50 th percentile current of 25.6 cm/s, which the permittee chose to use in the Visual Plumes modelling. The Department utilized two alternative, site and depth-specific current measurement studies that occurred in the vicinity of the City s outfall in the final mixing model selected. The first is an acoustic Doppler current profiler (ADCP) data collection effort performed as part of the Federal Aviation Administration s (FAA) Environmental Impact Study for extension of the runway safety area of the Kodiak Airport. This study collected data from Woody Island Channel at latitude North and longitude West, which places it approximately 666 meters (2,185 feet) east of the outfall terminus. The ADCP data measured the two horizontal components of the current (speed and direction) at multiple elevations between the bottom and surface of the water column for a month during October and November of Current measurements were collected every ten minutes. The Department elected to use only current data collected at the meter (20 to 36 foot) depths as this was most applicable to the depths that occur at the outfall. The ADCP data confirmed that the area has semidiurnal tides with a period of about 12 hours. The second site-specific current study was performed by the National Ocean and Atmospheric Association (NOAA) in Station KOD0904 was placed at ' North latitude and ' West longitude, placing it approximately meters (3,000 feet) northeast of the outfall terminus. This study occurred May 29, 2009 through July 11, 2009 and currents were measured at six minutes intervals at multiple depths. The Department elected to use only data from the meter (20-33 foot) depths as it was most representative of the depths that occur at the diffuser. The Department combined both the FAA and NOAA data (resulting in 57,714 individual current speed measurements) and determined the 90 th percentile current measured was 48.6 cm/s, the 50 th percentile current measured was 22.1 cm/s and the 10 th percentile current measured was 5.5 cm/s. The maximum current observed was cm/s. These speeds were all used in the Department s CORMIX modelling effort. The final model selected the 10 th percentile current as described in this Fact Sheet section, but the maximum observed current was used in the unsteady state model ran to confirm the final mixing zone model and the 50 th and 90 th percentile currents were used to examine the modelling scenarios present by the permittee in their mixing zone application. The final mixing model the Department selected indicated that at the 10 th percentile current (current speed used to simulate slack-tide conditions) during the dry season, at maximum observed effluent flows for the dry season, the acute ammonia WQ criteria was met relatively rapidly in the near field, a phenomenon consistently observed in the majority of the scenarios modelled. During the 10 th percentile Page 22 of 58

23 current condition of the maximum effluent flow and maximum effluent temperature observed during the dry season, chronic ammonia aquatic life WQ criteria requires more space and time to meet criteria, due to buoyant terminal layer spreading of the effluent plume. The density difference between the mixed flow and the ambient receiving water controls the trajectory and dilution of the plume. This phenomenon and the time and space it requires to occur in was confirmed by running a complementary unsteady state model that approximated tidal reversal conditions, which are the conditions expected at the 10 th percentile current slack-tide conditions where the tidal stream reverses, the water is relatively unstressed and the movement decreases. The unsteady model confirmed the steady state model almost exactly. Accordingly, the Department sized both the mixing zone length and width according to 10 th percentile current conditions, which were the critical conditions in which the least amount of dilution was provided. The instructions for mixing zone application Form 2M suggest sizing the width of a mixing zone in marine waters based on the 90 th percentile current. The modelling scenarios the Department ran did not support adhering to this guidance in this scenario as during 90 th percentile current conditions the plume was less than half as wide as it was during the 10 th percentile current conditions, indicating these were not critical conditions for plume width. In accordance with 18 AAC , the Department determined that the size of the mixing zone for the City s discharge is appropriate. The dilution factor and size of the mixing zone has decreased from the previous permit issuance. The acute mixing zone, driven by ammonia, has a surface area of 0.07 m 2 (0.4 meters wide and 0.15 meters long), and the chronic mixing zone, also driven by ammonia, has a surface area of approximately 4,119 m 2 (83.04 meters wide and 49.6 meters long). The chronic mixing zone is sized according to the dilution required by ammonia (18.5) to meet chronic aquatic life WQ criteria. The acute mixing zone size is sized according to the dilution required by ammonia to meet acute aquatic life WQ criteria (2.45). Both mixing zones are based on five years of monthly ammonia effluent data submitted by the permittee. Other pollutants included in the chronic mixing zone include WET, temperature, and FC bacteria. The CORMIX model indicates that the water quality criteria would be met relatively rapidly, approximately parallel to the direction of the ambient current (in both flooding and ebbing tidal directions). The mixing zone is sized to ensure: 1) the water quality criteria found in 18 AAC 70 are met at the boundary of the mixing zones, 2) the mixing zone is as small as practicable, and 3) compliance with all other applicable mixing zone regulations. Table 9 summarizes basic CORMIX inputs that were used to model the mixing zones. Figure 1 illustrates the approximate location of the mixing zone. Page 23 of 58

24 Figure 1: Approximate Mixing Zone Location Page 24 of 58

25 Table 9: Summary of CORMIX Model Inputs Parameter Modeled Maximum Expected Concentration Ambient Concentration Chronic Water Quality Criterion Acute Water Quality Criterion Ammonia mg/l mg/l 1.02 mg/l 7.72 mg/l Outfall and Receiving Waterbody Characteristics Outfall Type & Length Diffuser Length Average Depth at Discharge meters (900 foot) long outfall with submerged multiport diffuser 38.1 meters 8.36 meters Number & Size of Ports nine 4-inch diameter ports, four five inch diameter ports- average of 4.3 inch port diameter used (0.11 meters) Port Height above Seabed Density- Type A Linear Stratification Ambient Velocity Wind Velocity meters surface density sigma-t, bottom density sigma-t meters per second 10 th percentile current 2 meters per second Effluent Characteristics Flow Rate Temperature cubic meters per second (4.0 MGD) 16.7 º C Technology In accordance with 18 AAC (a)(3), the Department finds that available evidence reasonably demonstrates that the wastewater at the City WWTF will be treated to remove, reduce, and disperse pollutants using methods found by the Department to be the most effective and technological and economical feasible, consistent with the highest statutory and regulatory treatment requirements.. Secondary treatment is provided by an activated sludge process. The facility averages 96.2% removal of TSS and over 89.4% removal of BOD5. Additionally, this permit includes a compliance schedule to meet final effluent limits for FC bacteria that are more stringent than the previous permit Existing Use In accordance with 18 AAC , the mixing zone has been appropriately sized to fully protect the existing uses of Woody Island Channel. The existing uses have been maintained and protected under the terms of the previous permit. The permit reissuance application does not propose any changes that would result in a lower quality effluent. The size of the mixing zone will significantly decrease from the previous permit issuance once the compliance schedule for disinfection has been completed. Monitoring results indicate that the discharge neither partially nor completely eliminates an existing use of the water body outside of the mixing zone boundary. Exposure to acute concentrations of pollutants from the Page 25 of 58

26 effluent in the acute mixing zone would be no more than 1.7 seconds. Mixing zone modeling suggests that the flushing is adequate to ensure full protection of uses of the water body outside of the mixing zone. Results of WET tests performed indicate that toxicity should not exist at levels that might result in biological impairment or cause an affect or damage to the ecosystem that the Department considers so adverse that a mixing zone is not appropriate. DEC has determined that the existing uses and biological integrity of the water body will be maintained and fully protected under the terms of the permit as required by 18 AAC (a)(1-2), 18 AAC (a)(3), and 18 AAC (a)(4) Human Consumption In accordance with the conditions of the permit, and in accordance with 18 AAC (b)(2) and (b)(3), the pollutants discharged cannot produce objectionable color, taste, or odor in aquatic resources harvested for human consumption; nor can the discharge preclude or limit established processing activities or commercial, sport, personal use, or subsistence fish and shellfish harvesting. There is no indication that the pollutants discharged have produced objectionable color, taste, or odor in aquatic resources harvested for human consumption. Additionally, the discharge has not precluded or limited established processing activities or commercial, sport, personal use, or subsistence fish and shellfish harvesting. Signs are required to be posted to inform the public that certain activities such as harvesting of aquatic life for raw consumption and primary contact recreation should not take place in the mixing zone. The CORMIX modeling suggests that the maximum expected effluent concentrations of pollutants will be diluted rapidly and that the mixing zone will not preclude or limit established fishery activities per 18 AAC (b)(3). DEC has determined that application data and available mixing zone modeling suggests that pollutants discharged will neither produce objectionable color, taste, or odor in harvested aquatic resources for human consumption, nor preclude or limit fish and shellfish harvesting per 18 AAC (b)(2-3) Spawning Areas The mixing zone is authorized in the marine waters of Woody Island Channel. 18 AAC (h), which prohibits authorizing mixing zones in streams, rivers or other flowing fresh waters used for anadromous or resident fish spawning, does not apply. Discharges to fresh waters are not authorized under the permit Human Health In accordance with 18 AAC and 18 AAC , the mixing zone must be protective of human health and will not result in pollutants discharged at levels that will bioaccumulate, bioconcentrate, or persist above natural levels in sediments, water, or biota, or at levels that otherwise will create a public health hazard through encroachment on a water supply or contact recreation uses. An analysis of the effluent data that was included with the City s application for permit reissuance and the results of the RPA conducted on pollutants of concern indicate that the level of treatment is protective of human health. The effluent data was then used in conjunction with applicable WQ criteria, which serve the purpose of protecting human and aquatic life, to size the mixing zone to ensure all WQ criteria are met in the waterbody at the boundary of the mixing zone. Low-level concentrations of copper, nickel and zinc have been detected in the WWTF effluent. These pollutants are identified as bioaccumulative by EPA (EPA 2000). DEC is requiring that the permittee monitor copper at an increased frequency. The permittee will continue to monitor nickel and zinc at the frequency of three times every five years. This effluent data will be used to make future determinations about reasonable potential, the need for WQBELs, and/or the need for specific mixing zone authorizations for these parameters. DEC has determined that the permit satisfies Page 26 of 58

27 18 AAC (a)(1)(a-c), 18 AAC (b and c), and that the level of treatment at City of Kodiak WWTF is protective of human health Aquatic Life and Wildlife In accordance with 18 AAC and 18 AAC , the mixing zone authorized in the permit shall be protective of aquatic life and wildlife. Pollutants for which the mixing zone will be authorized will not accumulate in concentrations outside of the mixing zone that are undesirable, present a nuisance to aquatic life, cause permanent or irreparable displacement of indigenous organisms, or result in a reduction in fish or shellfish population levels. CORMIX modeling conducted for this discharge to Woody Island Channel incorporated the most stringent WQ criteria in the model for protection of the growth and propagation of fish, shellfish, other aquatic life, and wildlife, and all WQ criteria will be met at the boundary of the authorized mixing zone. CORMIX models of the outfall indicate that high dilution occurs relatively rapidly and pollutants discharged will have a relatively short residence time in the mixing zones prior to mixing to WQ criteria levels occurs. The Department determined that the mixing zones will not create a significant adverse effect to fish spawning or rearing, form a barrier to migratory species, fail to provide a zone of passage, result in undesirable or nuisance aquatic life, result in permanent or irreparable displacement of indigenous organisms, or result in reduction in fish population levels and that 18 AAC (a)(2)(A-C) and 18 AAC (b)(1) are met Endangered Species In accordance with 18 AAC (a)(2)(D), the authorized mixing zone will not cause an adverse effect on threatened or endangered species. DEC consulted the United States Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS) websites to identify any threatened or endangered species under their jurisdiction in the vicinity of the City of Kodiak WWTF Outfall. See Fact Sheet section 9.2 for summary information regarding critical habitat and endangered species. No detrimental effects to fauna in the area have been documented with previously authorized mixing zones for the facility, nor does the mixing zone appear to pose an undesirable nuisance to aquatic life. The RPA and CORMIX modeling resulted in an overall decrease in the size of the mixing zone (upon completion of the compliance schedule for disinfection), further reducing the possibility for any threatened or endangered species potentially in the area to come into contact with the treated wastewater. Due to the reduced size and short residence time of pollutants in the mixing zone, the Department has concluded that the mixing zones are sized to not cause an adverse effect on threatened or endangered species in the vicinity of the discharge. DEC will provide a copy of the permit and fact sheet to NMFS and USFWS when it is public noticed. Any comments received from the agencies regarding endangered species will be considered prior to issuance of the permit. 6.0 ANTIBACKSLIDING 18 AAC requires that effluent limitations, standards, or conditions must be at least as stringent as the final effluent limitations, standards, or conditions in the previous permit. 18 AAC (c) also states that a permit may not be reissued to contain an effluent limitation that is less stringent than required by effluent guidelines in effect at the time the permit is renewed or reissued. All permit effluent limits, standards, and conditions such as monitoring requirements in the permit are at least as stringent as in the previously issued permit and are consistent with 18 AAC Permit monitoring requirements that changed significantly from the previous permit issuance include the removal of receiving water monitoring for fecal coliform bacteria and the reduction in the total number of receiving water monitoring stations from four to one. These revised receiving water monitoring requirements are based on information that was not available during the previous permit issuance. This new information includes the compliance schedule in the permit for disinfection of the effluent, the inclusion of ammonia WQBELs that necessitate receiving water monitoring to select an appropriate WQS numeric criteria based on ph, salinity and temperature and the presence of copper in the Page 27 of 58

28 effluent. The altered receiving water monitoring requirements are appropriate and necessary given the evolving understanding of the facility s pollutants of concern and the amount of time that has passed since the previous permit issuance. Additional information about changes to receiving water monitoring is available in Fact Sheet Section 4.6. Additionally, the frequency of TRC monitoring was reduced from twice per month when not disinfecting, to only requiring monitoring if the facility is disinfection. This decision was made to make the permit consistent with other domestic wastewater and POTW permits that only require TRC monitoring if the facility is disinfecting utilizing chlorine. This decision is supported by five years of TRC data taken twice per month which.confirms that there were no detected TRC effluent results above the method detection limit/compliance level of 0.05 mg/l implemented in the permit. Additional information about changes to TRC monitoring is available in Fact Sheet APPENDIX B Section B Accordingly, no further backsliding analysis is required for this permit reissuance. 7.0 ANTIDEGRADATION Section 303(d)(4) of the CWA states that, for water bodies where the water quality meets or exceeds the level necessary to support the water body's designated uses, WQBELs may be revised as long as the revision is consistent with the State's Antidegradation policy. The Antidegradation Policy of the WQS (18 AAC ) states that the existing water uses and the level of water quality necessary to protect existing uses must be maintained and protected. This section analyzes and provides rationale for the Department s decisions in the permit issuance with respect to the Antidegradation Policy. The Department s approach to implementing the Antidegradation Policy, found in 18 AAC , is based on the requirements in 18 AAC 70 and the Department s Policy and Procedure Guidance for Interim Antidegradation Implementation Methods, dated July 14, Using these procedures and policy, the Department determines whether a water body, or portion of a water body, is classified as Tier 1, Tier 2, or Tier 3, where a higher numbered tier indicates a greater level of water quality protection. At this time, no Tier 3 waters have been designated in Alaska. Woody Island Channel is not listed as impaired on DEC s most recent Alaska s Final 2010 Integrated Water Quality Monitoring and Assessment Report; therefore, a Tier 1 designation is not warranted. Accordingly, this antidegradation analysis conservatively assumes that the discharge is to a Tier 2 water body. The State s Antidegradation Policy in 18 AAC (a)(2) states that if the quality of water exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water (i.e. Tier 2 waters), that quality must be maintained and protected. The Department may allow a reduction of water quality only after finding that five specific requirements of the Antidegradation policy at 18 AAC (a)(2)(A)-(E) are met. The Department findings follow: 18 AAC (a)(2)(a). Allowing lower water quality is necessary to accommodate important economic or social development in the area where the water is located. Based on the evaluation required per 18 AAC (a)(2)(D) below, the Department has determined that the most reasonable and effective pollution prevention, control, and treatment methods are being used and that the localized lowering of water quality is necessary. The City of Kodiak WWTF collects, treats, and disposes of wastewater from the City of Kodiak. Yearround residents number approximately 6,100 according the permittees APDES application form 2A. In addition to seasonal industries such as commercial fishing, the City of Kodiak hosts seasonal tourists, resulting in an increase in demand for wastewater treatment services. Ultimately, by providing wastewater treatment services, the City of Kodiak WWTF contributes not only to the local economic and social development of Kodiak, but to the overall economic and social development of the State of Alaska as well. The Department determined that the permitted activities are necessary to accommodate important economic and social development and the anticipated lowering of water quality is necessary for these purposes and that the finding is met. Page 28 of 58

29 18 AAC (a)(2)(b). Except as allowed under this subsection, reducing water quality will not violate the applicable criteria of 18 AAC or 18 AAC or the whole effluent toxicity limit in 18 AAC Section 1.2 of the permit requires that the discharge shall not cause a violation of the WQS at 18 AAC 70 except if excursions are authorized in accordance with provisions in 18 AAC (i.e., mixing zone, variance, etc.). As a result of City of Kodiak s WWTF s reasonable potential to exceed water quality criteria for ammonia, and available assimilative capacity in the receiving water, a mixing zone is authorized in the WWTF wastewater discharge permit in accordance with 18 AAC (See Fact Sheet section 5.5). The resulting effluent end-of-pipe limits and monitoring requirements in the permit (See Table 5) protect water quality criteria, and therefore, will not violate the water quality criteria found at 18 AAC outside the authorized mixing zone. Site-specific criteria as allowed by 18 AAC have not been established for Woody Island Channel and are therefore not applicable. The permittee must conduct WET tests once per year to determine if the effluent is creating chronic toxicity in the receiving water. If WET tests reveal that the discharge has toxicity, the permittee shall perform accelerated testing and identify the source of the toxicity. The permittee must notify DEC of the exceedance in writing within 14 days of receipt of test results. WET results from this permit issuance will be used when the permittee applies for reissuance of the permit to ensure the applicable criteria of 18 AAC are met. The Department finds that the reduced water quality will not violate applicable water quality criteria at the boundary of the authorized mixing zone and that the finding is met. The Department has determined that the reduction in water quality will not violate the applicable criteria of 18 AAC , 18 AAC , or 18 AAC , and that the finding is met. 18 AAC (a)(2)(C). The resulting water quality will be adequate to fully protect existing uses of the water. The WQ criteria, upon which the permit effluent limits are based, serve the specific purpose of protecting the existing and designated uses of the receiving water. Woody Island Channel is protected for all designated uses (see Fact Sheet section 5.3); therefore, the most stringent water quality criteria found in 18 AAC and in the Alaska Water Quality Criteria Manual for Toxic and Other Deleterious Organic and Inorganic Substances (DEC 2008) were selected for use in the RPA. This will ensure that the resulting water quality at and beyond the boundary of the authorized mixing zone will fully protect all designated uses of the receiving waterbody. The Department has reviewed the expected volume of discharge, the types and amounts of regulated pollutants, and the effluent limits imposed in the permit. The Department has determined that City s treatment of wastewater will result in adequate water quality to fully protect existing uses of the waterbody and that the finding is met. 18 AAC (a)(2)(D). The methods of pollution prevention, control, and treatment found by the Department to be most effective and reasonable will be applied to all wastes and other substances to be discharged. The methods of prevention, control, and treatment the Department finds to be most effective and reasonable are currently in use at the facility and include meeting federal (40 CFR 133) and state (18 AAC ) secondary treatment requirements. 18 AAC allows for the discharge of domestic wastewater from a community domestic wastewater treatment works only if the discharge has received a minimum of secondary treatment. The City of Kodiak WWTF produces secondary treated domestic wastewater via an activated sludge process. Federal secondary treatment standards at 40 CFR , adopted by reference at 18 AAC (e), describe minimum levels of effluent quality in terms of BOD5, TSS, and ph that are achievable by secondary treatment facilities. Accordingly, DEC has applied the BOD5 and TSS minimum Page 29 of 58

30 achievable effluent quality levels as TBELs in this permit. The previous permit contained WQ criteria for ph that are more stringent than the ph TBELs. The City of Kodiak WWTF has consistently demonstrated compliance with the more stringent WQ ph criteria; therefore, the previous permit ph limits are retained as the most stringent limitations in the permit. The City of Kodiak WWTF utilizes a variety of measures to prevent, control and treat the pollution that may be generated as a result of the facility s wastewater treatment operations. The City of Kodiak WWTF Operation and Maintenance Plan (OMP) establishes standard operational procedures and regular maintenance schedules for the prevention, control, and treatment of all wastes and other substances discharged from the facility. Best management practices requirements in the OMP that prevent or minimize the release of pollutants into Woody Island Channel include minimum components such as preventative maintenance, spill prevention, water conservation, and public information and education. Section 2.7 of the permit requires that pollutants removed in the course of treatment such as screenings and grit be disposed of in accordance with Alaska Solid Waste Management Regulations at 18 AAC 60. The Department has determined that the methods of pollution prevention, control, and treatment found to be most effective and reasonable will be applied to all wastes and substances discharged from the City of Kodiak WWTF, under the practices and requirements set out in the permit, and that the finding is met. 18 AAC (a)(2)(E). All wastes and other substances discharged will be treated and controlled to achieve (i) for new and existing point sources, the highest statutory and regulatory requirements; and (ii) for nonpoint sources, all cost-effective and reasonable best management practices. The applicable highest statutory and regulatory treatment requirements are defined in 18 AAC (30) (as amended June ) and in the previously referenced July 14, 2010 DEC guidance titled Policy and Procedure Guidance for Interim Antidegradation Implementation Methods. Accordingly, there are three parts to the definition, which are: (A) any federal technology-based effluent limitation guidelines (ELG) identified in 40 CFR and 40 CFR , as amended through August 15, 1997, both adopted by reference at 18 AAC ; (B) minimum treatment standards in 18 AAC ; and (C) any treatment requirements imposed under another state law that is more stringent than a requirement of this chapter. The first part of the definition includes all federal technology-based effluent limit guidelines, including For POTWs, effluent limitations based upon..secondary Treatment at 40 CFR 125.3(a)(1) defined at 40 CFR , adopted by reference at 18 AAC (e), which are incorporated in the permit. The second part of the definition 18 AAC (B) (2003) appears to be in error, as 18 AAC describes discharges to sewers and not minimum treatment. The correct reference appears to be the minimum treatment standards found at 18 AAC , which refers to domestic wastewater discharges only. The authorized domestic wastewater discharge is in compliance with the minimum treatment standards found in 18 AAC as reflected by the permit limits specifying secondary treatment standards. The third part includes any more stringent treatment required by state law, including 18 AAC 70 and 18 AAC 72. The correct operation of equipment, water quality monitoring, and implementation of secondary treatment standards for the domestic wastewater discharge (18 AAC ) will control the discharge and satisfy all applicable state requirements. Neither the regulations in 18 AAC 70 and 18 AAC 72, nor another state law that the Department is aware of impose more stringent requirements than those found in 18 AAC 70. After review of the applicable statutory and regulatory requirements, including 18 AAC 70, 18 AAC 72, and 18 AAC 83, the Department finds that the discharge from the City of Kodiak WWTF s wastewater discharge meets the highest applicable statutory and regulatory requirements and that the finding is met. Page 30 of 58

31 8.0 OTHER PERMIT CONDITIONS 8.1 Quality Assurance Project Plan The permittee is required to develop procedures to ensure that the monitoring data submitted are accurate and to explain data anomalies if they occur. The permit reissuance process revealed Quality Assurance Project Plan (QAPP) completeness issues, data reporting, and laboratory quality assurance/quality control issues specific to ammonia and TRC. The permittee is required to submit an updated QAPP for review and approval within 120 days of the effective date of the final permit. The QAPP shall consist of standard operating procedures the permittee must follow for collecting, handling, storing and shipping samples; laboratory analysis; precision and accuracy requirements; data reporting, including method detection/reporting limits; and quality assurance/quality control criteria. The permittee is required to amend the QAPP whenever any procedure addressed by the QAPP is modified. The approved QAPP shall be retained on site and made available to the Department upon request. 8.2 Operation and Maintenance Plan The permit requires the permittee to properly operate and maintain all facilities and systems of treatment and control. Proper operation and maintenance is essential to meeting discharge limitations, monitoring requirements, and all other permit requirements at all times. The permittee is required to review and update the Operation and Maintenance Plan (OMP) that was required under the previous permit within 120 days of the effective date of the reissued permit. The permittee must also provide DEC written notice upon completion and implementation of the OMP. The plan shall be reviewed annually, be updated as necessary, be retained onsite, and made available to the Department upon request. Permit Section requires that best management practices be included in an OMP with the purpose of preventing or minimizing the release of pollutants to Woody Island Channel. 8.3 Industrial User Survey The permittee is required to submit with their permit reissuance application, Form 2A, an Industrial User Survey report. The goal of the Industrial User Survey is to identify industries that discharge nondomestic wastewater into the City of Kodiak WWTF collection system (and ultimately the treatment system) that have the potential to adversely impact the treatment capabilities of the City of Kodiak WWTF and the quality of the treated wastewater. The results will be used to determine if the City of Kodiak WWTF may need to develop a pretreatment program or include pretreatment requirements in a future reissued wastewater discharge permit. The pretreatment program is authorized under 40 CFR Part 403, adopted by reference in 18 AAC (g)(2). 8.4 Electronic Discharge Monitoring Report The permittee must submit DMR data electronically through NetDMR per Phase I of the E-Reporting Rule (40 CFR 127) upon the effective date of the permit. Authorized persons may access permit information by logging into the NetDMR Portal ( DMRs submitted in compliance with the E-Reporting Rule are not required to be submitted as described in permit APPENDIX A Standard Conditions unless requested or approved by the Department. Any DMR data required by the Permit that cannot be reported in a NetDMR field (e.g. mixing zone receiving water data, etc.), shall be included as an attachment to the NetDMR submittal. DEC has established an e-reporting Information website at that contains general information about this new reporting format. Training materials and webinars for NetDMR can be found at Phase II of the E-Reporting rule will integrate electronic reporting for all other reports required by the Permit (e.g., Annual Reports and Certifications) and implementation is expected to begin Page 31 of 58

32 December Permittees should monitor DEC s E-Reporting Information website ( for updates on Phase II of the E-Reporting Rule and will be notified when they must begin submitting all other reports electronically. Until such time, other reports required by the Permit may be submitted in accordance with APPENDIX A Standard Conditions. 8.5 Compliance Schedule In accordance with 18 AAC and 18 AAC , when appropriate, APDES permits may include a series of required steps and deadlines (i.e., a compliance schedule), which upon completion, enables the permittee to meet the permit s WQBEL. A compliance schedule establishes remedial measures in a permit, including an enforceable sequence of interim requirements such as actions, operations, or milestone events leading to compliance. Compliance schedules authorized under 18 AAC require that if a permit establishes a schedule of compliance that exceeds one year, the schedule must set out interim requirements and dates for their achievement. If the time necessary to complete any interim requirement is more than one year, the schedule shall require reports on progress towards completion of the interim requirements. The City of Kodiak WWTF was originally designed to disinfect effluent via chlorination. The NPDES permit issued by EPA to the City of Kodiak in 1988 contained a stipulation that The effluent shall not be chlorinated unless disinfection is necessary to meet the fecal coliform limit. The 1988 NPDES permit monthly average effluent limit for FC bacteria was 500,000 FC/100 ml and the daily maximum effluent limit was 1,000,000 FC/100 ml. The 1988 NPDES chlorination prohibition permit condition resulted in the City of Kodiak WWTF ceasing disinfection of the effluent. When the discharge permit was reissued by EPA in 1999, it contained a WQBEL and monitoring requirements for TRC, despite the fact that the facility did not disinfect the effluent with chlorine. The City of Kodiak submitted a mixing zone application in March 2016 requesting continued authorization of a rectangular mixing zone extending 1600 meters long on either side of the outfall diffuser (total length 3200 meters), up to 400 meters wide, resulting in a FC bacteria mixing zone almost two miles long and a quarter mile wide. The maximum observed effluent concentration of FC bacteria in the most recent five years of WWTF performance was 281,000 FC/100 ml. Marine WQ criteria for harvesting for consumption of raw mollusks and other raw aquatic life for FC bacteria limit result in a daily maximum effluent concentration of 43 most probable number (MPN) per 100 ml (using the fivetube decimal dilution test). The 3,200 meter long FC bacteria mixing zone authorized in the State of Alaska Certificate of Reasonable Assurance in 1999 can no longer be authorized in a fashion compliant with WQS, including mixing zone regulations that became effective in One regulatory issue the City of Kodiak s proposed mixing zone encountered is that the Department cannot authorize a mixing zone any wider than approximately 167 meters in Woody Island Channel due to a cross-sectional area restriction found in 18 AAC (e)(1)(A). Another significant regulatory issue for the proposed mixing zone was that the Department s analysis of the City of Kodiak s proposed mixing zone never resulted in a confirmation that the FC bacteria mixing zone proposed by the City of Kodiak would meet the FC bacteria WQ criteria within the distances specified (3,200 by 400 meters). This meant that the WQ criteria were not met at the boundary of the proposed mixing zone, which violated mixing zone regulations at 18 AAC This analysis was confirmed in the City of Kodiak s own mixing zone application, which showed that using their proposed modelling approaches (which differed from the Department s final approach, which is described in Fact Sheet section 5.5), the concentration of FC bacteria would not always be less than 43 FC/100 ml at the boundary of the mixing zone during all mixing scenarios presented. Authorizing a large mixing zone for FC bacteria would greatly exceed the dilution required and the size of mixing zone necessary for toxic pollutants such as Page 32 of 58

33 ammonia. That would not conform with mixing zone regulations at 18 AAC (a)(2), which require a mixing zone to be as small as practicable. The final regulatory mixing zone issue was that mixing zone regulations at 18 AAC (a)(3) specify that the Department will authorize mixing zones only if evidence reasonably demonstrates that an effluent will be treated to remove and reduce pollutants using methods found by the Department to be the most effective and technologically and economically feasible, consistent with the highest statutory and regulatory treatment requirements. Various disinfection methods are available and widely implemented in Alaska at facilities both smaller and larger in size than the City of Kodiak WWTF. In an effort to make effluent limits for FC bacteria in the City of Kodiak WWTF permit consistent with other APDES permits for POTWs that disinfect and to greatly decrease the size of the authorized mixing zone, the Department is revising effluent limits for FC bacteria in this permit issuance. The FC limits for this permit issuance have been revised to 200 FC/100 ml for a monthly average, 400 FC/100 ml for a weekly average, and 800 FC/100 ml for a daily maximum. 200 and 400 FC/100 ml match the regulatory definition of disinfect at 18 AAC (21). The level 800 FC/100 ml was chosen to be consistent other recently issued APDES permits. The dilution provided by the chronic mixing zone for ammonia is The Department calculated that the dilution required to meet the effluent limits of 200, 400 and 800 FC/100 ml for FC bacteria is available within the chronic mixing zone sized by the driving parameter ammonia. The Department performed a review of APDES wastewater discharge individual permits for domestic wastewater treatment facilities performing secondary treatment and found 16 facilities ranging in design flow from 25,000 gallons per day to 58 MGD were all performing some type of disinfection of their effluent. Additionally, disinfection is a requirement of the Department s general permit for domestic wastewater discharges, which authorizes over 100 facilities with design flows less than 1.0 MGD. Disinfection is an effective and economically feasible treatment to reduce FC bacteria that the City of Kodiak WWTF can undertake and of which, the facility is already partially designed for; therefore, a compliance schedule for a FC bacteria WQBEL is appropriate. The Department is implementing a compliance schedule to allow the time necessary for the facility to come into full compliance with WQS for FC bacteria, as allowed in 18 AAC and 18 AAC The compliance schedule established in the permit accounts for possible modifications to the facility and includes interim annual reporting requirements consistent with 18 AAC (b). These interim requirements include providing the Department annual reports that include descriptions of potential upgrades to the WWTF, identifies potential sources of funding, and outlines proposed construction schedules. A five-year compliance schedule provides a reasonable and appropriate timeframe to achieve compliance with the final FC bacteria effluent limits; however, Permit Section requires that the permittee achieve compliance as soon as possible. While the facility possesses a chlorine contact chamber, it has not been in use for quite some time. Additionally, a disinfection solution involving chlorination would likely still require upgrades to the WWTF to achieve dechlorination given the relatively low end of pipe WQBELs for TRC that cannot be modified due to antibacksliding regulations and are capable of being met with appropriately implemented dechlorination. The five-year compliance schedule is consistent with other APDES permits for domestic wastewater treatment facilities requiring disinfection. The schedule accounts for time required to pursue funding for treatment upgrades if necessary, submission of plans for review by the Department, design and construction, and becoming fully operational and achieving compliance with the final FC bacteria effluent limits. A shorter schedule would make achieving compliance with final FC bacteria effluent limits more difficult as upgrades to the WWTF are needed. The Alaska s Clean Water Actions Grant deadline for funding applications for the State Fiscal year 2018 was February 15, Should the City Page 33 of 58

34 of Kodiak wish to pursue funding under that grant, they would need to wait until the State fiscal year 2019 grant cycle. This would delay implementation of upgrades to the WWTF if funding under this program is pursued. Additionally, getting supplies to remote Alaska coupled with a short construction season further limit how quickly capital projects can be completed. Permit Section further describes how the permittee will achieve compliance with the final FC bacteria effluent limits prior to the conclusion of the five year compliance schedule. The Department defined achieve compliance to mean not exceeding the monthly average FC bacteria effluent limit (200 FC/100 ml) for three consecutive months, not exceeding the weekly average FC bacteria effluent limit (400 FC/100 ml) for four consecutive weeks, and not exceeding the daily maximum FC bacteria effluent limit (800 FC/100 ml) for four consecutive samples. Regardless of compliance status, the final FC bacteria effluent limits go into effect at the conclusion of the five year period. The Department determined that the FC bacteria effluent limits in the previous permit issuance are reasonable interim FC bacteria effluent limits, and are consistent with the interim mixing zone authorization. While the FC bacteria schedule of compliance is in effect, the interim FC bacteria effluent limits depicted in Table 10. Interim FC Bacteria Effluent Limits Table 10: Interim FC Bacteria Effluent Limits Parameter Units Monthly Average Effluent Limits Daily Maximum Sample Location Monitoring Frequency Sample Frequency Sample Type FC Bacteria FC/100 ml 200,000 a 500,000 b Effluent 1/Week Grab Footnotes: a. If more than one FC bacteria sample is collected within a 30-day (monthly) period, the average result must be reported as the geometric mean. When calculating the geometric mean, replace all results of zero, 0, with a one, 1. The geometric mean of n quantities is the nth root of the product of the quantities. For example the geometric mean of 100, 200, and 300 is (100 X 200 X 300)1/3 = b. Reporting is required within 24 hours if the daily maximum limit is violated. See Permit APPENDIX A, Section Standard Conditions APPENDIX A of the permit contains standard regulatory language that must be included in all APDES permits. These requirements are based on the regulations and cannot be challenged in the context of an individual APDES permit action. The standard regulatory language covers requirements such as monitoring, recording, reporting requirements, compliance responsibilities, and other general requirements. 9.0 OTHER LEGAL REQUIREMENTS 9.1 Ocean Discharge Criteria Section 403(a) of the CWA, Ocean Discharge Criteria, prohibits the issuance of a permit under Section 402 of the CWA for a discharge into the territorial sea, the water of the contiguous zone, or the oceans except in compliance with Section 403. Permits for discharges seaward of the baseline of the territorial seas must comply with the requirements of Section 403, which include development of an Ocean Discharge Criteria Evaluation (ODCE). An interactive map depicting Alaska s baseline plus additional boundary lines is available at: The map is provided for information purposes only. The U.S. Baseline committee makes the official determinations on baseline. Page 34 of 58

35 A review of the baseline line maps revealed that the baseline extends across Chiniak Bay, seaward of Long and Woody Island across to Chiniak. The City of Kodiak WWTF outfall terminus is positioned landward of the baseline of the territorial sea; therefore, Section 403 of the CWA does not apply to the permit, and an ODCE analysis is not required to be completed for this permit reissuance. Further, the permit requires compliance with WQS such that 40 CFR (b) is met and therefore the discharge is presumed not to cause unreasonable degradation of the marine environment. 9.2 Endangered Species Act NMFS is responsible for administration of the Endangered Species Act (ESA) for listed cetaceans, seals, sea lions, sea turtles, anadromous fish, marine fish, marine plants, and corals. All other species (including polar bears, walrus, and sea otters) are administered by the USFWS. The Endangered Species Act (ESA) requires federal agencies to consult with the National Oceanic and Atmospheric Administration (NOAA), NMFS and the USFWS if their actions could beneficially or adversely affect any threatened or endangered species. As a state agency, DEC is not required to consult with these federal agencies regarding permitting actions; however, DEC voluntarily contacted the agencies to notify them of the proposed permit issuance and to obtain listings of threatened and endangered species near the discharge. The USFWS has directed the Department to consult their Information, Planning, and Conservation System ( to obtain lists of threatened and endangered species within the jurisdiction of the USFWS in the City of Kodiak WWTF s discharge area. The Department used this website to gain an approximate determination that the area surrounding Outfall 001 may contain endangered short-tailed albatross. The area may also contain threatened northern sea otters and critical habitat areas for the northern sea otter and Steller sea lion. NOAA has directed the Department to consult their Marine Mammal Species Range and Critical Habitat Interactive map at The Department used this website to gain an approximate determination that the area surrounding Outfall 001 may contain endangered Steller sea lions, humpback whales, North Pacific right whales, and sperm whales. This fact sheet and the permit will be submitted to the agencies for review during the public notice period and any comments received from these agencies will be considered prior to issuance of the permit. 9.3 Essential Fish Habitat Essential fish habitat (EFH) includes the waters and substrate (sediments, etc.) necessary for fish from commercially-fished species to spawn, breed, feed, or grow to maturity. The Magnuson-Stevens Fishery Conservation and Management Act (January 21, 1999) requires federal agencies to consult with NOAA when a proposed discharge has the potential to adversely affect (reduce quality and/or quantity of) EFH. As a state agency, DEC is not required to consult with NOAA on EFH; however, DEC voluntarily contacted NOAA to notify them of the proposed permit issuance and to obtain listings of EFH in the area. NOAA has directed the Department to consult their EFH Mapper at to obtain locations of EFH in the area of Woody Island Channel the City of Kodiak WWTF discharges to. The Department used this website to gain an approximate determination that the area the City of Kodiak WWTF discharges to could be EFH for all five species of Pacific salmon, skate, Pacific cod, sculpin, arrowtooth flounder, yellowfin sole, squid, walleye pollock, rock sole, and flathead sole. DEC will provide NMFS with copies of the permit and fact sheet during the public notice period. Any comments received from NMFS regarding EFH will be considered prior to issuance of the permit. Page 35 of 58

36 9.4 Sludge (Biosolids) Requirements Sludge means any solid, semi-solid, or liquid residue removed during the treatment of municipal wastewater or domestic sewage. State and federal requirements regulate the management and disposal of sewage sludge (biosolids). The permittee must consult both state and federal regulations to ensure proper management of the biosolids and compliance with applicable requirements State Requirements The Department separates wastewater and biosolids permitting. The permittee should contact the Department s Solid Waste Program for information regarding state regulations for biosolids. The permittee can access the Department s Solid Waste Program web page for more information and who to contact Federal Requirements EPA is the permitting authority for the federal sewage sludge regulations at 40 CFR Part 503. Biosolids management and disposal activities are subject to the federal requirements in Part 503. The Part 503 regulations are self-implementing, which means that a permittee must comply with the regulations even if no federal biosolids permit has been issued for the facility. A POTW is required to apply for an EPA biosolids permit. The permittee should ensure that a biosolids permit application has been submitted to EPA. In addition, the permittee is required to submit a biosolids permit application to EPA for the use or disposal of sewage sludge at least 180 days before this APDES permit expires in accordance with 40 CFR (c)(2) and (q) [see also 18 AAC and 18 AAC , respectively]. The application form is NPDES Form 2S and can be found on EPA s website, under NPDES forms. A completed NPDES Form 2S should be submitted to: U.S. Environmental Protection Agency Region 10, NPDES Permits Unit OWW-130 Attention: Biosolids Contact 1200 Sixth Avenue, Suite 900 Seattle, WA The EPA Region 10 telephone number is Information about EPA s biosolids program and CWA Part 503 is available at and either search for biosolids or go to the EPA Region 10 website link and search for NPDES Permits. 9.5 Permit Expiration The permit will expire five years from the effective date of the permit. Page 36 of 58

37 10.0 References 1. Alaska Department of Environmental Conservation, Alaska Water Quality Criteria Manual for Toxics and Other Deleterious Organic and Inorganic Substances, as amended through December 12, U.S. Environmental Protection Agency, National Pollution Discharge Elimination System (NPDES) Permit Writers Manual. Office of Wastewater Management, Water Permits Division State and Regional Branch Office of Water Regulations and Standards. Washington DC, September EPA-833-K Alaska Department of Environmental Conservation, Alaska s Final 2010 Integrated Water Quality Monitoring and Assessment Report, July 15, Alaska Department of Environmental Conservation, Interim Antidegradation Implementation Methods. Retrieved from Interim_Antidegradation_Implemenation_Methods.pdf 5. U.S. Environmental Protection Agency Technical Support Document for Water Quality-based Toxics Control. Office of Water Enforcement and Permits, Office of Water Regulations and Standards. Washington DC, March EPA/505/ NMFS, Office of Habitat Conservation, Essential Fish Habitat Mapper v3.0. Retrieved from 7. Alaska Department of Fish and Game, Fish Resource Monitor. Retrieved from 8. Alaska Department of Environmental Conservation, 2003, Water Quality Standards, as amended June 26, 2003, Alaska Department of Environmental Conservation 18 AAC Alaska Department of Environmental Conservation, Alaska Pollutant Discharge Elimination System (ADPES) Permits Reasonable Potential Analysis and Effluent Limits Development Guide, as amended June 30, U.S. Environmental Protection Agency, Appendix to Bioaccumulation Testing and Interpretation for the Purpose of Sediment Quality Assessment Status and Needs Chemical-Specific Summary Tables, February EPA-823-R Robert Doneker and Gerhard Jirka, CORMIX User Manual, U.S. Environmental Protection Agency, EPA- 823-K , December MixZon, Telephone conversation with Robert Doneker re: Mixing Zone Inputs, March 15, Federal Aviation Administration, Alaska Region, Environmental Program Manager Leslie Gray, correspondence re: EIS ADCP data. December 29, U.S. Environmental Protection Agency, Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to West Coast Marine and Estuarine Organisms, First Edition. USEPA, Office of Research and Development, National Exposure Research Laboratory, EPA-600-R , Cincinnati, OH. 15. U.S. Environmental Protection Agency, Denton DL, Miller JM, Stuber RA EPA Regions 8, 9 and 10 Toxicity Training Tool. January San Francisco, CA. 16. Alaska Department of Environmental Conservation, 2016, Wastewater Disposal, as amended October 22, 2016, Alaska Department of Environmental Conservation 18 AAC National Ocean and Atmospheric Administration, Kodiak, AK Station ID KOD0904. Data retrieved from on February 22, Alaska Department of Environmental Conservation, 2017, Water Quality Standards, as amended February 5, 2017, Alaska Department of Environmental Conservation 18 AAC 70. Page 37 of 58

38 APPENDIX A. FACILITY INFORMATION Figure 2: Wastewater Treatment Plant Vicinity Map Page 38 of 58

39 Figure 3: City of Kodiak WWTF Outfall Map Page 39 of 58

40 Figure 4: Wastewater Treatment Plant Process Flow Diagram Page 40 of 58