Groundwater Studies

The assessments are the result of thousands of hours of work by outside experts, providing the most comprehensive information gathered to date about the groundwater near Duke Energy's coal ash sites in North Carolina.

The company and NCDENR will use this science and engineering, along with other information, to determine how best to continue to protect groundwater as ash basins are closed. As coal plants have served customers' needs over the decades, the remaining ash has been managed in basins and, at many sites, also in lined landfills.

Generally, the data gathered through the installation of about 900 new monitoring wells and more than 7,000 soil and water samples across the state have been consistent with historical data provided to state regulators over many years.

While study continues, the assessments indicate:

• Allen – Groundwater near ash basins is flowing away from neighbors' private wells. The area where groundwater is affected is confined to the ash basins and coal pile on Duke Energy property. Please read the Allen groundwater assessment executive summary and simplified graphic for more information.
• Asheville – Groundwater near ash basins is flowing toward the river, and no private wells exist between the basins and river. The vast majority of plant neighbors are served by municipal water, not private well water. Furthermore, the river serves as a barrier between groundwater near ash basins and groundwater supplying private wells on the other side. As a result, wells across the river would not be influenced by groundwater flow from the basins. While low levels of boron are detectable near the few private wells southwest of the plant, boron levels are well below the state standard for boron in groundwater. Please read the Asheville groundwater assessment executive summary and simplified graphic for more information.
• Belews – The area where groundwater is affected is primarily near the ash basin. There is an area on the west side of plant property where sampling reported elevated levels of total dissolved solids (TDS) and chloride above background concentrations found in wells away from the basin, but less than state groundwater standards. This indicates groundwater flow at the northwestern edge of the ash basin is potentially migrating off site to an isolated area where there are no private wells. Please read the Belews Creek groundwater assessment executive summary and simplified graphic for more information.
• Buck – Groundwater near ash basins is flowing away from neighbors' private wells. The area where groundwater is affected is confined primarily to the ash basins on Duke Energy property. Please read the Buck groundwater assessment executive summary and simplified graphic for more information.
• Cape Fear – Groundwater near ash basins is flowing away from neighbors' properties. There are no private wells in the nearby vicinity. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basins. Please read the Cape Fear groundwater assessment executive summary and simplified graphic for more information.
• Cliffside – Groundwater near ash basins is flowing away from neighbors' private wells. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basins. Please read the Cliffside groundwater assessment executive summary and simplified graphic for more information.
• Dan River – Groundwater near ash basins is flowing away from neighbors' properties. Neighbors are served by municipal water, and there are no private wells in the nearby vicinity. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basins. Please read the Dan River groundwater assessment executive summary and simplified graphic for more information.
• H.F. Lee – Groundwater near ash basins is flowing away from neighbors' private wells. Affected groundwater has migrated off site in isolated areas where there are no private wells. Please read the H.F. Lee groundwater assessment executive summary and simplified graphic for more information.
• Marshall – Groundwater near the ash basin is flowing away from neighbors' wells. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basin and closed ash landfills. Please read the Marshall groundwater assessment executive summary and simplified graphic for more information.
• Mayo – Groundwater near the ash basin is flowing away from neighbors' private wells. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basin. Please read the Mayo groundwater assessment executive summary and simplified graphic for more information.
• Riverbend – Groundwater near ash basins is flowing away from neighbors' properties. Neighbors are served by municipal water, and there are no private wells in the nearby vicinity. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basins and storage areas. Please read the Riverbend groundwater assessment executive summary and simplified graphic for more information.
• Roxboro – Groundwater near ash basins is flowing away from neighbors' private wells. The area where groundwater is affected is confined to Duke Energy property and is primarily near the ash basins. Please read the Roxboro groundwater assessment executive summary and simplified graphic for more information.
• Sutton – As previously reported, the company is addressing off-site groundwater impacts by partnering in 2013 with the local water utility to extend a new municipal water line to serve residents in the area. That project is underway now. In addition, we are installing 12 "interceptor" wells that will pump groundwater back to the plant. Private drinking water wells sampled by NCDENR to date show levels higher than state groundwater standards only for substances that are also naturally occurring and common in the region's soil. Please read the Sutton groundwater assessment executive summary and simplified graphic for more information.
• Weatherspoon – Groundwater near the ash basin is flowing away from neighbors' private wells. The area where groundwater is affected is confined to the ash basin and the former coal pile area on Duke Energy property. Please read the Weatherspoon groundwater assessment executive summary and simplified graphic for more information.
• Data demonstrate that water quality in the respective lakes and rivers near power plants has not been affected by groundwater near our ash basins.

Next Steps

The next phase of work includes additional sampling and computer modeling in the next few months to better understand how groundwater conditions are expected to change over time. Where groundwater impacts need to be addressed, the sampling results and modeling will inform the best engineering solutions to protect groundwater long term.

Ongoing Safe Basin Closure

In addition to completing groundwater assessments, we have ash excavation in progress at three Carolinas coal plants and recently announced our recommendation to excavate an additional 12 basins in North Carolina for technical reasons unrelated to groundwater. We continue to study 12 remaining basins in North Carolina and will use this groundwater data and modeling to inform safe basin closure recommendations that are based in good science and engineering.