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HomeMy WebLinkAboutNC0004979_Other Correspondence_20190424(� DUKE ENERGY James Wells Vice President Environmental, Health and Safety Programs & Environmental Sciences 526 South Church Street Mail Code EC13K Charlotte, NC 28202 (980)373-9646 April 24, 2019 NP R Via Overnight Mail WQIHO4; -GIONAL OFFICE N100RUSVILIL.' RE Corey Basinger Mooresville Regional Office Regional Supervisor North Carolina Department of Environmental Quality Division of Water Resources Water Resources - Water Quality Regional Operations 610 East Center Avenue, Suite 301 Mooresville, NC 28115 bon meage North Carolina Department of Environmental Quality tar.,r� n ,ality l�erftin�,t�sg� �� Division of Water Resources 1617 Mail Service Center Raleigh, NC 27699-1617 Subject: Report Under Special Order by Consent — EMC SOC WQ S 17-009 Duke Energy Carolina, LLC — Allen Steam Station NPDES Permit NC0004979 Quarterly Progress Report Dear Messrs. Basinger and Sledge: On behalf of Duke Energy Carolinas, LLC (DEC), I am submitting to you the Allen Steam Station Progress Report summarizing the work and activities undertaken with respect to closure of coal ash surface impoundments as required by the Allen Steam Station NPDES Permit NC0004979 Special Order by Consent (SOC), SOC No. S17-009 Section 2.c.2). As required by the SOC, I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Messrs. Basinger and Sledge April 24, 2019 Page 2 Please direct any questions concerning the Allen Steam Station NPDES Permit NC0004979 SOC No. S 17-009 to Elizabeth Glenn at (980) 373-0530. Vice PUesident, Environment, Health & Safety - Programs -and -Environmental- Sciences Duke Energy Attachment: Allen Steam Station Quarterly Progress Report CC: Richard Baker, Duke Energy Elizabeth Glenn, Duke Energy Randy Gantt, Duke Energy George Hamrick, Duke Energy Paul Draovitch, Duke Energy Matt Hanchey, Duke Energy Randy Hart, Duke Energy Background and Summary On April 18, 2018, Duke Energy Carolinas, LLC (DEC) and the North Carolina Environmental Management Commission entered into a Special Order by Consent — EMC SOC S17-009 (SOC) applicable to the Allen Steam Station (Allen). This report is submitted in accordance with Section 2c. of the SOC. In compliance with Section 2.c., this report summarizes the work and activities undertaken with respect to decanting work and closure of coal ash surface impoundments at Allen. The quarterly reports are due no later than the last day of January, April, July, and October for the duration of the SOC, once the decanting process has begun. Allen Steam Station is located in Belmont, NC, along the west shore of Lake Wylie. Lake Wylie is a man- made reservoir created by the impoundment of the Catawba River. Allen is a five -unit, 1140 megawatts, coal-fired generating facility. The Allen Station began commercial operation in 1957 with Units 1 and 2. Unit 3 began operation in 1959, Unit 4 in 1960, and Unit 5 in 1961. The ash basins at Allen cover approximately 293 acres with a current ash inventory of approximately 19.3 million tons of ash as of February 2019, which is inclusive of the Active Ash Basin, Retired Ash Basin, Retired Ash Basin Landfill, and the Distribution of Residual Solids facilities. Allen historicallywet sluiced coal combustion residual (CCR) products into two surface impo11 undments located on the property. These surface impoundments are known as the Retired Ash Basin (also referred to as the Inactive Ash Basin) and the Active Ash Basin, which are impounded by the followine dams: Retired Ash Basin (GASTO-016) Active Ash Basin (GASTO-061) The Retired Ash Basin received CCR products from initial operation in 1957 until 1973, when it reached capacity and was retired. Allen then commissioned the Active Ash Basin and began wet sluicing CCR products into this new basin. In 2009, Allen replaced its fly ash wet sluicing operation with a dry ash handling system and began placing dry fly ash into a landfill constructed over a portion of the Retired Ash Basin (Permit No. 36-12). Allen ceased wet sluicing of bottom ash in February 2019 when the dry bottom ash system became operational. The Active Ash Basin was removed from service in February 2019 upon the completion of dry bottom ash handling and diversion of all other wastewater flow to a newly lined retention basin. Closure Plans A number of potential closure options are being considered for Allen. Following a comprehensive assessment, Duke Energy will submit its Closure Plan to NCDEQ for review and approval in accordance with CAMA requirements. Decanting Status In compliance with this SOC, Duke Energy initiated design and procurement efforts in Q3 2018 for a decanting water treatment system at Allen. Purchase Orders were awarded in January 2019 for the WWTS pad and electrical infrastructure installations, as well as a Purchase Order for the OEM water treatment supplier. Wastewater flows were removed from the basin on February 9, 2019. Duke Energy provided advance notice for the projected start date of decanting to NCDEQ on January 24, 2019, as required by the NPDES Permit, and written notification for the Initiation of Decanting per the SOC on February 14, 2019. Allen: 1