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HomeMy WebLinkAboutPresentation - Belews CreekCOAL COMB USTION RESID UAL IMPO UNDMENT RISK CLASSIFICATIONS March 2016 Collaboration between: Division of Water Resources Division of Waste Management Division of Energy, Mineral and Land Resources Department of Environmental Quality COAL COMB USTION RESID UAL IMPO UNDMENT RISK CLASSIFICATIONS Background: • Under the historic Coal Ash Management Act (CAMA) of 2014, all coal ash impoundments in North Carolina are required to be closed. • The deadlines for closure depend on the classification of each impoundment as low, intermediate, or high. • CAMA required the Department of Environmental Quality (DEQ) to make available to the public a summary of the initial draft proposed classifications in December 2015, and a full report in January 2016. • These draft proposed classifications are based on the information available to the department as of December 2015 and are posted on the departments website, local library, and health department. Department of Environmental Quality 2 COAL COMB USTION RESID UAL IMPO UNDMENT RISK CLASSIFICATIONS After the release of the summary of the initial draft proposed classifications, CAMA requires the following process: • DEQ must make available a written declaration that is a detailed report explaining the technical and scientific background data and analyses behind the draft proposed classifications. • Publish a summary of the detailed report in the local newspapers. • Make the report available to the local health director and accessible at the local library. • A public meeting in each county with a coal ash facility. • Consider all public comments and develop final proposed classifications. Department of Environmental Quality 3 COAL COMB USTION RESID UAL IMPO UNDMENT RISK CLA SSIFI CA TIONS Closure Deadlines • High risk impoundments: Dec. 31, 2019 • Closure plan due by Dec.31, 2016 • Intermediate risk impoundments: Dec. 31, 2024 • Closure plan due by Dec. 31, 2017 • Low risk impoundments: Dec. 31, 2029 • Closure plan due by Dec. 31, 2018 COAL COMB USTION RESID UAL IMPO UNDMENT RISK CLASSIFICATIONS Four of Duke's 14 facilities are designated as high-risk by the coal ash law. Under CAMA, the department is required to consider the following factors, at a minimum, in proposing classifications for the remaining 10 facilities: 1. Any hazards to public health, safety, or welfare. 2. Structural condition and hazard potential. 3. Consideration of surface 4. Consideration of groundwater. 5. The location and nature of all receptors. 6. All factors influencing the movement of contaminants. 7. Consideration of coal combustion residuals in the impoundment. 8. Position in 100 -year flood plain 9. Any other factor the department deems relevant to the establishment of risk. COAL COMBUSTION RESIDUAL IMPOUNDMENT RISK CLASSIFICATIONS The department incorporated all of the preceding criteria into three primary categories that were used to evaluate each impoundment: • Structural Integrity • Impact to Surface Water • Impact to Groundwater The draft classification process was iterative and occurred over a series of months. Recommendations regarding the impoundments were amended and updated as additional scientific and technical information was received, reviewed and verified. Department of Environmental Quality I BELE WS CREEK STEAM STA TION RISK CLASSIFICATION BELEWS CREEK STEAM STATION RISK CLASSIFICATION Department of Environmental Quality BELE WS CREEK STEAM STATION RISK CLASSIFICATION Overall Risk Classification DEQ has ropposed the risk classification for the Active Ash Basin as LOW TO INTERMEDIATE. Groundwater Key Factor: Based on the information received to date, there appears to be no downgradient receptors located 1,500 feet downgradient of the impoundment compliance boundary. The following data gaps related to groundwater uncertainty include: • Incomplete capture zone modeling for up -gradient and side -gradient supply wells • Incomplete geochemical modeling • Incomplete background concentration determination • Horizontal and vertical extent of contamination downgradient not well defined • Potential contamination resulting from the on-site landfill and structural fill not addressed • Groundwater flow in bedrock not well defined (Data gaps are currently being addressed by Duke Energy and their findings will be presented to the DEQ in supplemental reports.) Department of Environmental Quality ry I BELE WS CREEK STEAM STATION RISK CLASSIFICATION Surface Water Key Factor. The impoundment is not located within the 100 - year floodplain. • Active Ash Basin. LOW RISK. This CCR impoundment is sited along a reservoir, has a 135 foot tall embankment, has an outfall and is designed to discharge. CCR impoundment is sited along a reservoir and is not located within a 100 -year floodplain. Department of Environmental Quality I * This figure depicts landscape positions in regards to the 100 - year flood level and river valley floodplain for the ash basin at the Belews Creek Steam Electric Plant. BELE WS CREEK STEAM STATION RISK CLASSIFICATION Dam Safety Key Factor. The impoundment received a high risk ranking before any repairs are made, an intermediate risk rating once repairs are made, and a low risk rating once repairs are made and the impoundment has been dewatered. State of Structural Stability and Maintenance: • Active Ash Basin (STOKE -116). High risk before repairs are made. Intermediate Risk once repairs are made. Low Risk after repairs are made and the impoundment has been dewatered. (4 repair plans have been approved and of those 1 repair plan has been completed by Duke.) Department of Environmental Quality a BELE WS CREEK STEAM STATION RISK CLASSIFICATION We will now receive public comments To view additional information please visit www.deg.nc.gov The public comment period will close on April 18, 2016 You may submit comments three ways, all weighted equally: • Here orally and/or in writing • Email to belewscreekcomments@ncdenr.gov • Postal mail to: N.C. Department of Environmental Quality, Attn: Toby Vinson, 1612 Mail Service Center., Raleigh, NC, 27699-1612. Department of Environmental Quality