Division of Surface Water Response to Comments

Transcription

1 Division of Surface Water Project: NRG Power Midwest LP Avon Lake Generating Station, National Pollutant Discharge Elimination System (NPDES) Permit Ohio EPA ID #: Agency Contacts for this Project Division Contacts: Zorica Dejanovic, (330) Cole Miller, (614) Public Involvement Coordinator: Kristopher Weiss, (614) Ohio EPA held a public meeting on April 25, 2018, with a comment period from Dec. 6, 2017 to May 4, 2018, regarding NRG Power Midwest LP Avon Lake Generating Station (). This document summarizes the comments and questions received at the public meeting and during the comment period. Ohio EPA reviewed and considered all comments received during the public comment period. By law, Ohio EPA has authority to consider specific issues related to protection of the environment and public health. Often, public concerns fall outside the scope of that authority. For example, concerns about zoning issues are addressed at the local level. Ohio EPA may respond to those concerns in this document by identifying another government agency with more direct authority over the issue. In an effort to help you review this document, the questions are grouped by topic, often summarized and organized in a consistent format. The final permit and fact sheet are located at the following addresses: General Public Comment Response Approximately 100 comments and testimonials were provided after the initial public comment period was extended. The first seven items address questions and comments provided by the public. The remaining items (eight-20) address comments received from Sierra Club, U.S. EPA, and the permittee.

2 November 2018 Page 2 of 14 For reference, the following units are used in the discussion: Unit Abbreviation Equivalent Milligram per liter mg/l Parts per million Microgram per liter µg/l Parts per billion Nanograms per liter ng/l Parts per trillion Comment 1. Mercury 1.1 Mercury Variance Many commenters requested that the mercury variance be denied. One commenter cited the mercury variance rules which require reasonable progress toward achieving pollutant minimization. Specifically, variances must be denied without reasonable progress. : The mercury variance is proposed in the final permit action. The permittee has made reasonable progress toward implementing the pollutant minimization plan. The original variance granted in the 2011 permit renewal was a monthly average concentration limit of 8.0 ng/l. Ohio EPA has reviewed data since the draft permit was proposed in December 2017 and has included a revised limit of 2.6 ng/l which is based on the 95 th percentile of the projected population. The permittee s 2017 annual average is 1.26 ng/l which is less than the intake average of 2.22 ng/l per the permittee s Year 7 mercury pollutant minimization plan ng/l is also less than the most restrictive criterion of 1.3 ng/l. Source Monthly Limit (ng/l) Timeframe of effluent data used 2011 Renewal 8.0 June 2005 Aug Draft 3.7 April 2012 March Final 2.6 Sept August Mercury Exposure Many commenters expressed concern for the protection of drinking water and safety of fish consumption with respect to the mercury variance. : The variance mercury standards are presented below. A monthly average mercury limit of 2.6 ng/l will be protective of all but the wildlife criteria.

3 November 2018 Page 3 of 14 Source Value (ng/l) Comments Drinking Water 2,000 Drinking Water Maximum Contaminant Level Surface Water 1,700 Aquatic life maximum 3.1 Protection of drinking water and fish consumption 2.6 Proposed Limit 1.3 Protection of wildlife such as the bald eagle. The proposed limit is protective of drinking water criteria and fish consumption. However, Ohio EPA has a fish consumption advisory for Lake Erie, with two species on the advisory for mercury. Additionally, there s a statewide advisory for sensitive populations (i.e., women of child-bearing age and children under age 15) to eat no more than one meal per week due to mercury. See the weblink below for more information. Comment 2. Permit Renewal Many commenters said the permit renewal should be denied. : The Ohio Administrative Code (OAC) rule has specific standards to deny permit renewals or to terminate a permit. Specifically: In renewing a permit, the director shall consider the compliance history of the permit holder and may deny the renewal if the director determines that the permit holder has not complied with the terms and conditions of the existing permit The permittee is in compliance with the current permit; therefore, there is no cause to deny the permit renewal application. Comment 3. Bottom Ash 3.1 Bottom Ash Disposal Some commenters expressed concern about proper disposal of bottom ash. : The permittee does not have a coal combustion residual (CCR) landfill onsite. CCR landfills are typically large impoundments where ash is disposed of in a wet slurry. Instead, the permittee dewaters the bottom ash and disposes of it at a licensed landfill or through beneficial reuse such as an alternative to

4 November 2018 Page 4 of 14 sand in concrete materials. Historically, the permittee used the Republic Landfill in Lorain County but currently uses the Rumpke landfill in Mansfield. See U.S. EPA s website for additional information regarding beneficial reuse of CCR materials: Timelines to cease discharge Some commenters asked that the timeline to implement the requirements of the effluent limitation guidelines (ELGs) related to bottom ash transport water be accelerated. : The proposed deadline remains at Dec. 31, Please see the Fact Sheet for revised details on the determination of the date. Comment 4. Fish Impingement and Entrainment 4.1 Timeline Commenters suggested a faster timeline to reduce fish deaths at the cooling water intake and requiring flow reductions when the power plant is not producing energy. : The interim compliance milestone to implement flow reduction when the plant is not operating has been decreased from 12 months to four months to account for time in public notice. The federal rules require a report to be prepared and peer reviewed. Ohio EPA and the permittee determined an alternative submittal schedule to provide the information and the permittee continues to work on it. A submittal date of Feb. 1, 2020, is appropriate. 4.2 Review Commenters requested additional information regarding how best technology available is determined. : The federal requirements largely separate the requirements of impingement and entrainment. For impingement, which is when aquatic life becomes stuck on the screens, facilities have seven options to be compliant. Three commonly selected options include closed-cycle recirculating systems, 0.5 feet per second through-screen design velocity and 0.5 feet per second through-screen actual velocity. See 40 CFR (c) for all the impingement mortality options.

5 November 2018 Page 5 of 14 For entrainment, which is when aquatic life passes through the screens and go through the cooling system, each intake is approved on a site-specific basis. Permittees that withdraw as much as NRG Avon Lake are required to look at closed-cycle recirculating systems, fine mesh screens with a mesh size of two millimeters or smaller, and water reuse or alternate sources of cooling. The Director of Ohio EPA will then determine whether the proposed technology is the site-specific best technology available based on five mustconsider factors and six may-consider factors. See 40 CFR (f) for the Director requirements for site-specific entrainment which is at the link below. Comment 5. Air Pollution Control Commenters indicated that air pollution is linked to water pollution and asked both be considered when deciding whether to issue or deny the NPDES permit. : Impacts from air deposition are not within the NPDES review authorities of this permit action. The Clean Air Act and its amendments address air pollution. For information regarding compliance, please see Ohio EPA s edocument search or contact the Northeast District Office at (330) Comment 6. Proposed Language Change Commenters made the following proposals: 6.1. Step-down schedule for reducing the allowable gallons of wastewater per day. A schedule was already included to eliminate discharges from bottom ash transport effective Dec. 31, Additionally, the permittee is required to submit annual progress reports toward reducing mercury concentrations in the discharge A deadline for elimination of toxic discharges. See Response 6.1. above A required annual report on fish kills.

6 November 2018 Page 6 of 14 The required report discussed in Response 4.1. requires two years of sampling data in which the permittee will determine the fish mortality rate. Fish kills are directly proportional to the amount of water withdrawn. The amount of flow discharged is already reported to Ohio EPA and therefore, an additional report is unnecessary. For impingement, which is a measurement of aquatic life which is stuck on screens, there are mitigation strategies including low through-screen velocities and modified traveling screens which scoop and return impinged fish to the receiving stream in addition to reducing flow. Reduced velocities were found to protect 96 percent of the fish investigated by U.S. EPA 1. Modified traveling screens and other technologies would require two additional years of study and associated reported information. In both cases, additional reporting would be unnecessary Annual progress reports on efforts to eliminate mercury discharges. This is already required. See Response 6.1. above Decreasing discharge limits for bromides. The permit has been revised to require prior notification to Ohio EPA and the City of Avon Lake to use bromine. The permit continues to include a re-opener clause to incorporate other water quality-based effluent limits which allows Ohio EPA to incorporate any new standards for bromide. The permittee currently does not use chlorine, bromine, or bromide; however, the permit authorizes limited use of bromine at a level of 0.05 mg/l. The testing methodology for analyzing bromine, chlorine and other oxidants is the same which is why the parameter is total residual oxidants. Comment 7. Additional Comments and Questions Commenters had the following questions 7.1. When was the last inspection? 1 U.S. EPA Technical Development Document for the Final Section 316(b) Existing Facilities Rule (2014) Page 6-66

7 November 2018 Page 7 of 14 Ohio EPA inspected terms and conditions of the NPDES permit on July 24, No violations were noted What are the consequences of non-compliance and who is responsible? What happens if the owner ceases to exist? A maximum of $10,000 per each violation per day is the penalty allowed by law (Ohio Revised Code ). The owner of the facility is the entity to which the penalty would be assessed. The owner at the time of violations occurring would be responsible. If the corporation ceases to exist, Ohio would continue to have the authority to issue enforcement action for past non-compliance Why is there a difference of reported intake flow of 389 million gallons per day (MGD) discharged versus an intake of 427 MGD? The numbers provided were from different sources which accounts for the inadvertent discrepancy. Overall, the amount of water withdrawn will be the amount discharged with potentially a small amount of water lost to evaporation It was indicated that most of the discharge is once-through condense cooling water. What is the remaining amount and what are the specific contents? There are three final discharge points which were analyzed for pollutants. Only Outfall 002 had the potential to exceed a water quality standard which was for mercury. A table from the fact sheet is included for reference below. Outfalls 001, 002, and 004 are all direct-to-lake Erie discharges. The remaining stations are internal to the final outfalls.

8 November 2018 Page 8 of 14 Average Station Wastewater Source Treatment Utilized Receiving Stream Flow Rate* (MGD) 001 Once-thru cooling water discharge, boiler blowdown, heat exchanger Chlorine disinfection Lake Erie 527 Lake Erie Ash transport water, coal pile runoff, metal cleaning 004 Low volume waste system, oily water separator, floor drains Sedimentation, chemical precipitation, neutralization, gravity filtration Sedimentation, chlorine disinfection, neutralization, gravity filtration Lake Erie Ash recycle water overflow 604 Boiler blowdown Coal pile runoff Neutralization, chemical precipitation, pressure filtration Treated metal cleaning wastewater Neutralization, chemical precipitation, pressure filtration Non-contact cooling water *Average is the 95 th percentile of monthly averages 7.5. The permit does not address heat pollution. The permittee demonstrated the thermal plume does not interfere with the designated or existing uses of Lake Erie based on a mixing zone study. Therefore, no additional measures are required The permit does not address storm fallouts. If the term fallout is regarding municipal storm water outlets, the City of Avon Lake is a regulated Municipal Separate Storm Sewer System (MS4) with requirements to minimize storm water pollution. Independent of the city, NRG Avon Lake also has its own storm water pollution prevention requirements Has Canada been consulted in terms of compliance?

9 November 2018 Page 9 of 14 No, Canada has not been consulted. For reference, Canada s most stringent mercury standard is 4 ng/l for methylmercury 2, compared to NRG Avon Lake s limit of 2.6 ng/l total recoverable mercury Is Lorain County in non-attainment for ozone and fine particulates? Yes, Lorain County is listed as non-attainment for particulate matter (PM2.5) and ozone. Please visit Ohio EPA s website for more information: Cooling Water Intake Structure Regulations [316(b)] Peer Review Comment 8: Response 8: Regarding the peer review requirements of 40 CFR (r)(13), the final permit should clarify that NRG must comply fully with all aspects of paragraph (r)(13), and provide a specific schedule for doing so that will allow adequate time for Ohio EPA to consider and provide input regarding the required peer review reports and incorporate the rest of 40 CFR (r)(13). (Ohio Environmental Council, Environmental Law & Policy, and Sierra Club [the Conservation Organizations ]) This change has not been made. The proposed compliance schedule references the requirements of 40 CFR (r)(13). The reference does not limit or change the requirements of the rule. To include all the rule language would be impractical as the application rule language is extensive. Additionally, the permittee provided a list of four peer reviewers on Jan. 5, 2018, for Ohio EPA to review. In a Jan. 19, 2018, , Ohio EPA indicated there were no objections to the list provided. Therefore, the language submitting the list of peer reviewers as soon as possible has been removed. 2 Canadian Council of Ministers of the Environment:

10 November 2018 Page 10 of 14 Comment 9: Response 9: The permittee requests that the Entrainment Characterization Study be removed from the list of reports which requires Peer Review. The application rule specifies (r)(10) through (r)(12) need to be peer reviewed. Condition I.C.1.c.i has been moved from the list of studies requiring peer review to the list of studies which require submittal (Part I.C.1.a). Monitoring, reporting, and recordkeeping requirements Comment 10: The Conservation Organizations request that the monitoring, reporting, and recordkeeping requirements of 40 CFR (b) be included in the permit. Response 10: This change has been made. See conditions Part II, Items P and Q. Interim Best Technology Available Comment 11: U.S. EPA requested the fact sheet indicate an interim Best Technology Available (BTA) determination based on reduction of intake volume due to a lower utilization rate Response 11: This change has not been made. The permittee s submittal from 2006 indicated that the maximum through-screen velocity was approximately 1.5 foot per second (fps). The impingement mortality options identified in 40 CFR (c) are prescriptive. While option 40 CFR (c)(6), Systems of technologies, does allow for flow reduction, the permittee would continue to withdraw 120 MGD on days not operating. Ohio EPA does not believe that a withdrawal of 120 MGD can be BTA even with the lower utilization capacity. More broadly, Ohio EPA disagrees that an affirmative interim BTA is required. The federal rule does not define interim BTA and references interim BTA only four times, primarily in the context of including requirements based on the Director s best professional judgment (BPJ).

11 November 2018 Page 11 of 14 For permits being renewed for the first time after the existing facilities rule became effective (Oct. 14, 2014), it is possible cooling water intake structure does not represent BTA nor could be reasonably interpreted as BTA on an interim basis. It would be arbitrary to make a BPJ determination without accounting for the final requirements of the rule. Instead, Ohio EPA interprets interim BTA as additional requirements necessary to align permittees with the required standards as well as setting a schedule to implement final determinations. For this permit, Ohio EPA has included interim compliance milestones to have the required application information submitted as soon as possible and will make a final determination after all information has been received. Additionally, the permittee is required to investigate additional flow reduction during non-operation which would ideally reduce through-screen velocities to less than 0.5 fps. Comment 12: The final permit must be revised to make clear that the permittee must, in its report on the feasibility of flow reduction during times the station is offline, also provide information about potential environmental and social benefits. This requirement would be consistent with the Clean Water Act s goals instead of solely making a feasibility determination based on economics. Additionally, Ohio EPA should require flow reduction as objectively defined by Ohio EPA instead of being defined by the permittee. (Conservation Organizations) Response 12: The fact sheet has been revised that there is no interim BTA. The interim measures may reduce impingement and entrainment, but reduction of flow may not be included in the final BTA demonstration. Therefore, the environmental and social benefit evaluation will still be done as part of the larger 316(b) report being submitted no later than Feb. 1, The final 316(b) report will be submitted within 12 months of the flow reduction feasibility report. While flow reduction may be part of the final BTA, the permittee may select other technologies to meet BTA or even other methods of flow reduction such as a variable speed pump. Therefore, no additional provisions of determining feasibility are proposed. Steam Electric Effluent Limitation Guidelines

12 November 2018 Page 12 of 14 Bottom Ash Transport Water Comment 13: U.S. EPA made the following comments: a. Add a footnote for final outfall 002 that references Part II.O which relates to the compliance date for bottom ash transport water. b. Revise Part II.O to address legacy wastewater associated with bottom ash transport water. c. Please include a means for evaluating the zerodischarge limitation for bottom ash transport water. d. Revise the Fact Sheet for clarity regarding ash waters generated prior to the as soon as possible date. Response 13: These changes have been made. Please see the permit and fact sheet for revisions. Comment 14: The fact sheet and permit must require the permittee to comply with the currently applicable final 2015 Effluent Limitation Guidelines (ELGs) limits, without commentary on the speculative possibility of any future modification of the final limits. (Conservation Organizations) Response 14: This change has not been made. The language in Part II, Item O of the draft permit requires the permittee to automatically comply with any new and/or alternative conditions that may be established in the Steam Electric Power Generating Effluent Guidelines. This mechanism allows the permit to automatically enforce any applicable ELGs, without modifying the permit language or compliance dates. Since the permit is not being modified, the modification rule (40 CFR ) does not apply. Comment 15: The Conservation Organizations request a more thorough description of how the Director determined the as soon as possible compliance date for the zerodischarge of bottom ash transport water. (Conservation Organizations) Response 15: Please see the revised fact sheet for additional information. Metal Cleaning Waste

13 November 2018 Page 13 of 14 Comment 16: U.S. EPA indicated that the metal cleaning wastes monitored and limited at internal outfall 611 should continue based on best professional judgment (BPJ). Response 16: This change has been made. Outfall 611 has been reinstated in the proposed permit with the existing limits. Comment 17: The permittee noted a reference to Outfall 611 in the permit and requested for the reference to be removed. Response 17: No change has been made. Mercury Variance As discussed in Response 16, Ohio EPA has re-instated Outfall 611. Therefore, the reference in Part II will continue. Comment 18: The Conservation Organizations request that the proposed mercury variance be reconsidered and to consider more recent information on the costs and benefits of end-of-pipe mercury controls. (Conservation Organizations) Response 18: No change has been made. The current permit has a mercury variance of 8.0 ng/l and in the proposed draft permit this value is reduced to 3.7 ng/l. The permittee has and continues to make reasonable progress toward the elimination of the discharge of mercury. More broadly, Ohio EPA agrees that controlling mercury pollution is important and has been very stringent on regulating point sources. In addition to eliminating the mixing zone for bioaccumulating chemicals of concern (BCCs) in the Lake Erie basin as required by the Great Lakes Initiative (GLI), Ohio EPA has extended this requirement to all of Ohio. Also, the variance is much more than a pass at meeting water quality criteria. Permittees that have been granted variances are required to develop pollutant minimization plans (PMPs), implement the PMPs, submit annual progress reports, and comply with an annual average mercury limit of 12 ng/l as well as a monthly average limit determined by effluent data. The general mercury variance has been

14 November 2018 Page 14 of 14 successful at reducing mercury concentrations in permitted dischargers and Ohio EPA believes further reductions are occurring. Bromide and Notification to Public Water Supply Comment 19: The Conservation Organizations request that Ohio EPA notify and consult municipalities to determine waterquality based effluent limitations for the Avon Lake Power Plant s bromide discharge are necessary to protect drinking water quality. (Conservation Organizations) Response 19: See Response 6.5. Comment 20: The permittee indicated that there was a typographical error related to cross-referencing in Part II Item N. Response 20: The permit has been revised to update the cross-reference. End of