Well Water Testing Information

Information on well testing for residents near a Duke Energy coal-fired electrical generating facility.

  • As part of the groundwater assessment being conducted in accordance with the Coal Ash Management Act of 2014, the N.C. Department of Environment and Natural Resources (DENR) is requiring that Duke Energy pay for the testing of all water supply wells within 1,500 feet of each of the utility's 14 coal-fired electrical generating facility boundaries.
  • Information being gathered during this investigation is being used to guide the successful closure of the coal ash basins. Additional wells may be sampled as part of later rounds of this well testing program.

Explanation of Federal and State Standards and Health Protective Levels

  • Federal maximum contaminant levels (MCLs), as part of the Safe Drinking Water Act, are the drinking water standards that regulate public drinking water supplies.The state has developed separate standards to protect the state’s groundwater resources.The separate standards that protect the state’s groundwater resources are found in 15A NCAC 02L.

    Federal standards are set as maximum levels not to be exceeded for certain constituents, which include metals and organic compounds. The maximum “do not exceed” level may not always represent the most health protective standard. Federal standards apply to public water supplies and take into account a vast array of inputs, including the cost and technology available to filtrate water to a certain level.

  • North Carolina groundwater standards are set by 15A NCAC 02L and are known as the 2L standards. These standards may differ from the federal Safe Drinking Water Act standards. They are calculated to protect the groundwater resource and human health and are, in most cases, more health protective than the federal drinking water standards. For example, the federal standard for total chromium (developed by the Environmental Protection Agency) is 100 parts per billion, while the North Carolina 2L standard for total chromium in groundwater is 10 parts per billion.

    DHHS has the authority to develop its own standards called health protective levels. These standards are based on the level of risk when the water is used or consumed.

  • Health protective levels are established solely on the basis of health effects data and do not consider technical or economic feasibility of removal. Health protective levels are sometimes set at levels lower than can be detected with current laboratory methods or removed from drinking water with available treatment technologies. A health protective level is a level of a contaminant in drinking water that reflects the risk from exposure to the contaminant. Health protective levels are not regulatory requirements. Many public drinking water systems do not meet all health protective levels.
  • It is entirely possible to meet the federal standard while exceeding the more health protective state standards.
  • State health officials have amended usage recommendations for hexavalent chromium and vanadium in public and private wells. The updated recommendations are the result of extensive study of how the federal government and other states manage drinking water. Individual well owners will be contacted by state officials with a letter and FAQ.  For more information please call the N.C. Department of Health and Human Services at 919-707-5900 during normal business hours.  

Well water testing information charts and map posted (10/16/2015) 

Comprehensive Site Assessments Posted (Continually Updated )


Reconnaissance Well Water Sampling Study Results Posted (Blog Post 8/28/2015)


Updated well water testing results and information posted (Blog Post 8/20/2015)

Information for well owners on test results and what they mean 

Updated well water testing results and information posted (Blog post 7/8/2015)

Updated well water testing results and information posted  (Blog post 6/11/2015)

Updated well water testing results and information posted (Blog post 5/20/2015)

Well water testing results and information posted (Blog post 5/5/2015)

Most results from drinking well tests show exceedences of state groundwater standards near coal ash ponds (Press release 4/21/2015)

Residents near coal ash facilities to receive well water test results (Press release 4/15/2015)

DENR invites residents near coal ash facilities to have water tested (Press release 12/17/2014)