THE ISSUE: Chemical contamination found in groundwater at plant.
OUR OPINION: Clean it up and communicate with the public.
Testing of groundwater on the Duke plant site has identified contamination from lithium, molybdenum and arsenic in excess of government groundwater protection standards (GWPS), and the company has been directed to develop remediation plans and communicate them to the public.
While levels in excess of GWPS were identified in testing, there has apparently been no impact on local wells because there are no homes near the site and the flow of groundwater is away from where homes are located.
Still, the fact that there is groundwater contamination is something that must be addressed.
The presumed source of the contaminants is coal ash that has been landfilled for years in an area between coal-fired units 4 and 5 and the new gas-fired power plant. In a coal plant, coal is finely pulverized before it is burned in the boiler. Ash from the process is either very fine particles called fly ash carried on the exhaust gases of the plant or heavier ash that falls to the bottom of the boiler. Fly ash is removed from the stream of exhaust gases by pollution control devices.
For years, most of the fly ash from the plant has been sold for use in the cement industry as part of the aggregate mix used in concrete, but some fly ash and bottom ash has been landfilled on the site. According to a consultant report, about 62 acres of the 4,730-acre site have been used to landfill ash from the coal plants since at least 1982.
Storing coal ash on plant sites has been commonplace for years at coal plants across the country, but within the past few years there has been increasing pressure on electric utilities to deal with the potential contamination from on-site ash storage.
The impetus for this began with a 2008 ash spill at a Tennessee Valley Authority power plant in Kingston, Tennessee, that flooded more than 300 acres of land and released coal ash into two rivers.
Additional pressure to act came after an early 2014 spill from a Duke Energy plant in North Carolina released more than 30,000 tons of coal ash into the Dan River.
The final Environmental Protection Agency rule on disposal of coal ash was signed in December 2014, and contains comprehensive requirements for safe storage and disposal of coal ash from power plants.
The monitoring wells on the site were installed in response to this rulemaking, and data from them is the basis for requiring action by Duke to alleviate the groundwater contamination.
The report outlines possible actions Duke can take to alleviate the problem, but leaves that final decision up to Duke and state environmental officials.
It is encouraging that the groundwater contamination identified appears to be only on the site and does not impact any local water wells, but at the same time, the report makes clear that some chemicals from ash have leached into groundwater.
We recognize the roots of this issue go back to the earliest days of the site when coal ash was first landfilled, but as the current owner, it is now incumbent on Duke to develop effective methods of preventing contaminants from leaving the site, and cleaning up those that are on the site.
It is also important for Duke to provide information to the public about this contamination, and to provide it in a clear, understandable way that the average resident will understand.