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HomeMy WebLinkAboutNCS000572_Dan River Application Modification_20141218DUKE ENERGY - December 17, 2014 Mr. Bradley Bennett State of North Carolina Department of Environment and Natural Resources Division of Energy, Mineral & Land Resources Stormwater Permitting Program 1612 Mail Service Center Raleigh, NC 27699-1612 Subject: NPDES Industrial Stormwater Permit Application Dan River Station Dear Mr. Bennett: Environmental Services Duke Energy 410 S. Wilmington Street Raleigh, NC 27601 Mailing Address: Mail Code NCRH 141 P.O. Box 1551 Raleigh, NC 27602 RECEIVED DEC 18 2014 DENR-LAND QUALITY STORMINATER PERMITTING Duke Energy submits the following information as an update to the industrial stormwater permit application for your consideration; during the development of an industrial stormwater permit for the Dan River Station. Specifically, the information below addresses decommissioning work that has the potential to involve the disturbance of coal or coal combustion residuals during decommissioning activities at the steam station. The following outfalls are identified as having this potential: SW003. SW004. SWO05 and SWO06: These four outfalls convey stormwater from small drainage areas west of the powerhouse. Their combined drainage area is approximately 3.8 acres. Coal ash residuals may also be encountered during grading activities and during demolition activities involving the dismantling of coal or ash handling equipment around the powerhouse area. Future SWO09: We request this outfall be added into the permit to address future decommissioning activities. This outfall conveys stormwater from a 45 acre area including the decommissioned powerhouse area, coal yard, and the 48 inch pipe area. Coal ash material may be transported through this area during future removal of coal ash from the site. Coal ash residuals may also be encountered during grading activities and during demolition activities involving the dismantling of coal or ash handling equipment around the powerhouse area and removal of railroad and ballasts. For some period of time the stormwater discharged through this outfall from the removal of the railroad and ballast will be directed through an in line treatment package before discharging through the outfall. In the future, as decommissioning of the site progresses, the yard sumps that are currently used to divert stormwater from the coal pile area and the breezeway; under the precipitator to the ash basin, will be diverted to the in line treatment package. This stormwater has the potential of containing coal residuals and coal ash. Future SW010: We request this outfall be added into the permit to address future decommissioning activities. This outfall conveys stormwater from a 77 acre area including the ash stack area, the 36 inch inlet pipe area and the ash stack perimeter. Coal ash residuals may be drained from the ash stack and other areas during storm events to future Outfall 010. Coal ash material may be transported through this area on haul roads during future removal of coal ash from the site. Coal ash residuals may also be encountered during grading activities and during demolition activities involving the removal of ash from the ash stack and ash basins, removal of railroad and ballasts, including a small area of petroleum remediation. Coal ash residuals may also be taken offsite by rail. During a site walk down in October Duke Energy identified a stormwater outfall at the Dan River Steam Station that was inadvertently omitted from the original stormwater permit application submitted in July 2014. Duke Energy requests the outfall be added to the permit. This outfall is identified as SW011 and is located adjacent to and west of SW003. This outfall conveys stormwater from an approximately 1 acre drainage area that contains sections of a railroad track that Duke Energy plans to remove. Coal residuals are present in the rail bed beneath these tracks, and coal and coal ash residuals may be encountered during grading activities and during demolition activities involving the dismantling of coal or ash handling equipment around the powerhouse area. Should you have any questions regarding this submittal or require additional information, please contact Steve Cahoon at 919-546-7457 or email steve.cahoon@duke-energy.com. Since Steve Cahoon Sr. Environmental Specialist Duke Energy Environmental Services Department