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Home My WebLink AboutNC0004987_Comments on Draft Permit_20180213DUKE ENERGY February 13, 2018 Mrs. Julie Grzyb NC DEQ — DWR 1617 Mail Service Center Raleigh, North Carolina 27699-1617 Subject- Comments on DRAFT NPDES Permit Marshall Steam Station NPDES Permit #. NC0004987 Catawba County Dear Mrs. Grzyb Richard E Baker Jr Director, Environmental Programs EHS-CCP 526 S Church Street Marl Code EC13K Charlotte, NC 28202 (704) 382-7959 RECEIVED/DENR/DWR FEB 14 2018 Water Resources Permitting Section On January 9, 2018, the Division of Water Resources issued the draft NPDES permit modification for Duke Energy's Marshall Steam Station During our review of the permit terms, our staff noted a few items that need additional clarification or correction. Some of the following items and interpretations of permit terms can and will have substantial impact on Duke Energy's ability to comply, the following errors and/or discrepancies were noted - 1 On page 15, Internal Outfall 010, in our permit application, Duke Energy stated the holding basin is not designed to treat coal pile runoff, but is a preliminary holding basin (see permit app item 3 dated August 22, 2017) Duke Energy did not requests an Internal Outfall associated with the preliminary holding basin. Duke requests that the Internal Outfall that was added to the permit be removed and that applicable TSS limits be implemented at the Lined Retention Basin Outfall 005. 2. On page 14, the WET (Whole Effluent Toxicity) concentration of 23% at Outfall 005 appears to be inaccurate Based on the removal of bottom ash sluice water and flow volumes provided as part of the permit, the WET IWC (Instream Waste Concentration) is 114%. Duke requests that this correction be made and that RPA (Reasonable Potential Analysis) calculations be evaluated against this IWC. 3 On page 2, ash basin overflow is identified as Outfall 007, but on page 15 it appears to be listed at Outfall 008 Duke Energy requests this be corrected. 4 On page 6 and 7, Duke Energy requests that the language related to dry bottom ash mirror the statutory language found in the coal ash management act. The statutory language states "On or before December 31, 2019, all electric generating facilities owned by a public utility shall convert to the disposal of "dry" bottom ash or the facility shall be retired." 5. On page 14, CAMA (Coal Ash Management Act) refers to the way the solid material is disposed of (i.e "dry") The majority of water associated with blow down flows from the submerged flight conveyer system will be sent to the FGD (Flue Gas Desulfurization) system and used as scrubber make-up water Incidental bottom ash submerged flight conveyer flows associated with, maintenance events, leakage, etc will be directed to Outfall 005 Duke requests that this be clarified in the description of flows associated with Outfall 005. 6 On page 11, 12 and 13, pH limits are associated with Internal Outfalls 003, 004, and 006 The fact sheet indicates this is completed in accordance with BPJ (Best Professional Judgment); however there is no evidence provided of BPJ analysis. Duke has provided support from EPA in interpretation that pH is permitted to be commgled internal to process as long as the final effluent is in acceptable range Duke requests that these pH limits be removed on these Internal Outfalls. 7 On page 13, Internal Outfall 006, will be the new internal outfall from the newly constructed FGD WWTS (Wastewater Treatment System), yet there is still a reference in the notes to the constructed wetlands. Duke requests that the sample location be changed to new FGD WWTS 8. Page 14, the copper limit listed for metal cleaning wastewater is inconsistent with the RPA spreadsheet and 40 CFR Part 423 The spreadsheet indicates no limit is necessary for outfall 005 The fact sheet indicates that the copper hrmt is applicable when metal cleaning wastewaters are released and are required by 40 CFR Part 423 Duke requests that the limits be set to 1.0 mg/1 in accordance with 40 CFR part 423. If you have any questions pertaining to our requests, please contact Brad Loveland at brad loveland@duke-energy com or 704-609-5637 Sincerely, W M Richard E Baker, Jr, P E, PMP Director, EHS CCP Environmental Programs Duke Energy cc. Sergei Chernikov (NCDEQ) Richard Baker (Duke Energy) Brad Loveland (Duke Energy) Scott LaSala (Duke Energy)