Loading...
HomeMy WebLinkAboutNC0001422_Letter to Duke Enery Regarding Decanting of WW_20140916J�,,TEO sr�r�s UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4 i; ATLANTA FEDERAL CENTER Syr moo? 61 FORSYTH STREET �t PROTEO ATLANTA, GEORGIA 30303 -8960 SEP 16 2014 Mr. Jeff Poupart Chief, Permitting Section Division of Water Quality North Carolina Department of Environment and Natural Resources 1611 Mail Service Center Raleigh, North Carolina 27699 -1611 S`� 22 2pt4 Subject: Letter Dated August 28, 2014 to Duke Energy Regarding Decanting of Wastewater Dear Mr. Poupart: This letter is to recommend that you withdraw the above - referenced letter (enclosed) and provide additional information about the potential effluent characteristics of the decanted wastewater. The U.S. Environmental Protection Agency is concerned that the August 28, 2014, letter will create uncertainty that could result in Duke Energy discharging wastewater with pollutants not authorized in a National Pollutant Discharge Elimination System ( NPDES) permit. The letter attempted to clarify for Duke Energy that it may proceed to "decant all the wastewater in the ash pond above the ash level" at each of 14 ash ponds under currently applicable NPDES permits. It prohibits Duke Energy from removing wastewater by dredging, trench excavation or other mechanical movement of the ash. The letter requests Duke to submit chemical characterization of the interstitial ash water and predicted volume of wastewater that would be generated by mechanical dewatering. The letter gives Duke no deadline by which to submit this information. The extent to which the pond can be drawn down through "decanting," as opposed to mechanical dewatering, is not clear in the letter. Rather than clarifying the issue, the letter creates uncertainty as to whether or not Duke is, or is not, authorized to discharge through the decanting process almost all liquid in the ash ponds, including interstitial ash water. It is also not clear whether Duke Energy, through this letter, is now newly authorized to discharge additional pollutants or higher pollutant concentrations that may be present due to any changes in effluent quality while the ponds are drawn down to the ash level. The letter indicates that the discharge of "supernatant" shall be monitored in accordance with the NPDES permit. However, the applicable permits only require monitoring for a limited number of pollutants once every six months. As a result, Duke Energy could draw the ponds down completely without taking a single sample to assess effluent quality, permit compliance, or water quality impact. Based on the EPA's review of Duke Energy's initial applications and permit documents, it does not appear that they requested authorization to conduct large -scale "decanting" or drawdown processes. It does not appear that Duke Energy disclosed information or data about the effluent characteristics and average flows of the decanted wastewater as required by 40 Code of Federal Regulations (CFR) Internet Address (URL) - http: / /www.epa.gov Recycled/Recyclable - Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer) 122.21(g). Nor does it appear that the North Carolina Department of Environment and Natural Resources contemplated large -scale decanting when issuing each of the 14 Duke Energy permits. The characterization of effluent quality and quantity in the permit applications appear to have been based on normal (gravity -based or passive) discharges of wastewater from the surface of the ponds after full settling has occurred. It is possible, however, that higher concentrations of pollutants may be present at deeper levels in the pond which will be discharged in the decanted wastewater. Further, the drawdown of wastewater may involve a much higher discharge rate than contemplated at the time the permits were issued. The letter also relates to 14 separate facilities, which have different receiving stream conditions, such as minimum flows and existing water quality which could affect a revised reasonable potential analysis. There was no information in the letter showing that any analysis of potential changes to effluent quality or quantity has been undertaken, nor any evaluation of the impact that such changes might have on a revised reasonable potential analysis for the additional discharge. Should this information already be available, please submit it for our evaluation. Without additional information, it is not possible to determine whether or not a formal permit modification would be necessary to authorize the discharge of changed effluent quality or volume that may occur during the decanting process at these 14 facilities. However, it is likely that at a minimum, significant additional monitoring (if not additional effluent limitations) during the decanting process would be warranted to ensure compliance with existing effluent limits and water quality standards. Without submittal of additional information by Duke Energy and subsequent revised reasonable potential analyses by DENR, made available to the EPA and the general public, discharges of additional decanted wastewater and additional pollutants will not qualify for NPDES permit shield protections under Section 402(k) of the Clean Water Act. The EPA therefore requests that DENR withdraw the letter and obtain additional data for each facility at which Duke Energy plans to decant or drawdown any and all additional wastewater to the ash level. If you have not already done so, the EPA requests that you require Duke Energy to provide the following information to DENR for each of the 14 facilities referenced in the letter: - data characterizing the effluent quality, of the decanted wastewater to the ash level; anticipated weekly average and maximum daily wastewater flow rates during drawdown; - pollutant concentrations in ash ponds at various depths between the base and surface of the ponds for all pollutants known or believed to be present in the discharge of decanted wastewater to the ash level; data showing background pollutant concentrations in receiving streams for all pollutants known or believed to be present in the discharge of the decanted wastewater; - low (7Q 10) stream flow in each receiving waterbody; and additional information about how it will be ensured that only decanted wastewater and not wastewater resulting from dredging the ash, excavating the trenches, or any other mechanical movement of the ash will be discharged. DENR should use the additional information to conduct revised reasonable potential analyses for each of the 14 facilities to inform decisions regarding the need for a permit modification and the potential need for additional monitoring requirements and /or water quality based effluent limits. The EPA requests that you provide us with this data and information for our review, as well as revised reasonable potential analyses. This will enable us to appropriately determine together with DENR whether or not formal permit modifications will be required to authorize Duke Energy to discharge decanted wastewater from these 14 facilities. The EPA notes that any permit modifications should include additional technology -based effluent limitations on a case -by -case basis based on best professional judgment as required section by § 402(a) of the Clean Water Act, 40 CFR § 122.44(a), § 123.25, and § 125.3. In particular any additional technology -based effluent limitations should address pollutants discharged from the ash ponds that are not included in effluent guidelines for the steam electric power generating industry in 40 CFR Part 423. In subsequent discussions with representatives of DENR, it appears that one of the worthy goals of this letter was to expedite closure of some ash ponds by addressing Duke Energy's need to remove wastewater from the pond. We recommend that you consider alternative enforceable approaches, in addition to potential permit modifications, that will achieve this purpose while ensuring protection of water quality during the decanting process. The EPA looks forward to working together with DENR to discuss our requests and recommendations to ensure that any discharges of wastewater from the decanting or dewatering process be appropriately authorized. Sincerely , r Mark J. Nuhfer, Chief Municipal and Industrial NPDES Section Enclosure cc: Mr. Mark McIntire Duke Energy RECEIVEDIDENR /DWR SEP 2 2 2014 Water Quality Permitting Section ALITOX-WWAA NCDENR North Carolina Department of Environment and Natural Resources Pat McCrory John E. Skvada, III Govemor Secretary August 28, 2014 CERTIFIED MAIL 7013 2630 00018998 1581 RETURN RECEIPT REQUESTED Mark McIntire Duke Energy 410 S. Wilmington Street Raleigh, NC 27601 Subject: Duke Energy Notice of Operating Condition Clarification Allen Steam Station NC0004979 Gaston County Buck Steam Station NC0004774 Rowan County Marshall Steam Station NC0004987 Catawba County Lee Steam Electric Plant NC0003417 Wayne County Weatherspoon Steam Electric Plant NC0005363 Robeson County Mayo Steam Electric Power Plant NCO038377 Person County Roxboro Steam Electric Power Plant NC0003425 Person County Riverbend Steam Station NC0004961 Gaston County Asheville Steam Station NC000396 Buncombe County Belews Creek NCO024406 Stokes County L.V. Sutton Electric Plant NC0041422 New Hanover County Cape Fear Steam Electric NCO003433 Generating Plant Chatham County Dan River Combined Cycle Plant NCO003468 Rockingham County Cliffside Steam Station NC0005088 Gaston County Dear Mr. McIntire: This letter is to clarify operating conditions for NPDES Permits issued to the above listed facilities. The Permittee is authorized by the existing NPDES wastewater permits to decant all the wastewater in the ash pond above the ash level provided the supernatant is directed through the same discharge point and monitored in accordance with the NPDES permit requirements. The Permittee is prohibited from removing wastewater by dredging the ash, excavating the trenches, or any other mechanical movement of the ash. Duke Energy shall submit the chemical characterization of the interstitial ash water from the ash basin and predicted volume of wastewater that will be generated by mechanical dewatering. If you have any questions about this letter, please contact me at (919) 807 -6309, or via e-mail at ieff.nouoartCa.ncdenr.Qov. Sincerely, ?'--Jeff Poupart Water Quality Permitting Section Chief cc: EPA Region IV, Mark Nuther Central Files DWR Regional Offices 1611 Mail Service Center, Raleigh, North Carolina 27699 -1611 Phone: 919.707 -90001 Internet: www.nowater.org An Equal Opportunity t Affirmative Anion Employer - Made in part by recycled paper RECEIVED/DENRlDWR SEP 2 2 2014 Water Quality Permitting Section (� DUKE ENERGY. September 30, 2014 Mr. Jeff Poupart Water Quality Permitting Section Chief N.C. Department of Environment and Natural Resources 1611 Mail Service Center Raleigh, NC 27699 -1611 RECEIVEDIDENRIDIAT OCT 0? 7M4 Water Ouality Permittinq Sectin Via email and UPS Re: Withdrawal of August 28, 2014 Operating Condition Clarification Letter Dear Mr. Poupart: This is to acknowledge receipt of your letter of September 19, 2014, withdrawing the previous letter of clarification of August 28, 2014. The letter of August 28, 2014, arose out of several shared concerns between Duke Energy and DENR. These included the efficient and safe operation of ash basins, particularly those that were inactive, and an understanding of how Duke Energy will move towards the closure of ash basins at former coal -fired plants currently undergoing decommissioning. In order to excavate ash from the ash basins (which Duke Energy has now been directed to do by an act of the North Carolina General Assembly), and to expedite necessary inspections and repairs, Duke Energy must first remove free - standing water. Given that this water had already undergone treatment, DENR clarified that the Company's NPDES permits authorized the decanting of free - standing water above the ash level so long as the removal did not cause exceedances of permit limits. Duke Energy notes that the amount of free - standing water that would be removed from these inactive basins would be well within the amount of treated water that the NPDES permits allow to be discharged on a daily basis. Before issuing the letter of August 28, 2014, DENR indicated on a number of occasions that the movement of free - standing water from inactive basins was permissible under the NPDES permits (so long as effluent limits were met), an interpretation with which Duke Energy agreed. The letter of August 28, 2014, thus did not constitute a departure from prior DENR practice nor was it a "new' interpretation, and we understood that it was simply a written confirmation of what DENR believed its permits allowed. Your letter of September 19, 2014, alters this position. Based upon the letter that we received from Mr. Mark J. Nuhfer, the Chief of Municipal and Industrial NPDES Section of Region IV of the Environmental Protection Agency, we understand that this RECEIVEDIDENRIDWR Mr. Jeff Poupart September 30, 2014 OCT 0 3 2014 Page 2 Water Quality Permittinq Sectinr departure comes at the request and direction of EPA for the purpose of addressing its concerns. Duke Energy will, of course, abide by this change. However, for the reasons set forth below, we believe that it is imperative for DENR, EPA and Duke Energy to meet to discuss and resolve the decanting of inactive basins as soon as possible so that closure and other essential maintenance, inspection and repair work may proceed expeditiously. Duke Energy appreciates the acknowledgement in Mr. Nuhfer's letter that expediting closure of inactive ash basins is a "worthy goal." Removing free - standing water from inactive basins will expedite Duke Energy's ability to perform any maintenance work needed to ensure basins continue to perform safely and reliably until closure, such as slip - sleeving or permanently closing pipes. Finally, Duke Energy has been directed by the General Assembly of North Carolina to remove ash from the basins at Riverbend, Asheville, Sutton and Dan River within sixty months. Requiring free - standing water to remain in these basins will not only delay the process for drying out the ash that is necessary before any excavation may occur, but as a practical matter could make meeting this deadline impossible. Unfortunately, withdrawal of DENR's letter has caused uncertainty surrounding regulatory requirements for moving forward with essential steps related to both closure and continued safe operations. Duke Energy is concerned that imposing a formal permitting process on the movement of free - standing water will substantially delay taking action on these matters. As such we suggest discussions take place between EPA, DENR and Duke Energy as soon as possible with a goal of identifying the regulatory framework that will allow this work to move forward. Duke Energy knows that DENR understands and appreciates the issues noted above. Duke Energy is committed to working with DENR and EPA to take the necessary engineering, scientific and environmentally sound steps to address ash basins and comply with the mandates of the elected officials of North Carolina. Sincerely, arry K. Sideris Senior Vice President Environmental, Health & Safety cc: Donald R. van der Vaart, DENR Thomas A. Reeder, DENR John Evans, Esp. General Counsel Mr. Jeff Poupart September 30, 2014 Page 3