Groundwater Reconnaissance Well Water Sampling Study Results Posted

Friday, August 28, 2015 - 12:00am

The N.C. Department of Environment and Natural Resources (DENR) released individual well water sampling results from its groundwater reconnaissance well water sampling study today. The study provides a limited evaluation of the distribution of metals and other parameters that may be naturally occurring in the groundwater, and provides data for staff to develop a better understanding of background concentrations of metals and other parameters in areas that are not hydraulically connected to groundwater beneath Duke Energy’s coal-fired power plant facilities. A collective summary of results was posted Aug. 17. The individual results were not made available before DENR confirmed receipt of results to well owners via certified mail.

Spreadsheet 
The updated spreadsheet provides a detailed account of the results at each individual well where
tests have been conducted. The spreadsheet compares the individual results of testing for coal ash-related metals and constituents with state and federal water quality thresholds, if such a threshold
exists. The spreadsheet includes 24 well test results. Of those tested, seven wells are in the vicinity of the Allen Steam Station, seven are in the vicinity of the Buck Steam Station, and 10 are in the vicinity of Marshall Steam Station. The spreadsheet of results is available here.

Health risk evaluations summary
DENR has provided a summary of the health risk evaluations (HRE) that were produced by the N.C.
Department of Health and Human Services (DHHS) and sent to homeowners along with the groundwater reconnaissance well water sampling study. The well water use recommendations are available for download at: NC DHHS Groundwater Reconnaissance Well Water Sampling Study Health Risk Evaluations.

Of the HRE’s, 20 of the 24 well owners received a “Do Not Drink” recommendation from the DHHS for exceedances of DHHS’ health screening levels or state Interim Allowable Maximum Contaminant Levels (IMAC). Do Not Drink recommendations for chromium 6 were issued based on the DHHS Health Screening Level of 0.07 ug/L. Do Not Drink recommendations for vanadium were issued based on the IMAC threshold of 0.3 ug/L. Of the 24 wells sampled, there were: 
• 12 Do Not Drink Recommendations for chromium 6 and vanadium
• 7 Do Not Drink Recommendations for vanadium and resample for chromium 6
• 4 Incomplete/resample for chromium 6
• 1 Do Not Drink recommendation for iron and manganese

In carrying out the Coal Ash Management Act, DENR is also overseeing a comprehensive groundwater assessment of drinking water wells near all 14 of the state’s facilities with coal ash ponds. The comprehensive groundwater assessments will be the driving force behind the agency’s efforts to determine whether any contaminants in wells are naturally occurring or from the coal ash ponds. DENR will require Duke Energy to provide well owners with alternative drinking water supplies if the agency determines any contamination came from the coal ash ponds.