BIG STONE COUNTY -- A public interest group is charging that heavy metals and chemicals are leaching from coal ash stored at the Big Stone power plant near Milbank, S.D., and contaminating groundwater at the site.
The South Dakota Department of Environment and Natural Resources -- charged with regulating the ash storage -- refutes the claims contained in the report by the Environmental Integrity Project.
The report "In Harm's Way'' takes aim at what it calls inadequate regulations nationwide to regulate coal ash storage. The report charges that groundwater contamination has been found at three dozen coal ash sites in 21 states. It was released to the public on Thursday.
A telephone press conference hosted Thursday by the Sierra Club in Minnesota focused on the report's findings for the Big Stone power plant.
According to the report, arsenic levels were found at 13 times the federal standard in one of the monitoring wells at the site.
The report claimed that in 21 of 25 monitoring wells, groundwater was found to be contaminated.
Big Stone's coal ash landfill, bottom ash pond, and seven waste disposal ponds have contaminated groundwater with heavy metals and other toxins in excess of state and federal standards, according to the report.
All of the monitoring ponds are located on the power plant property, and there are no monitoring wells providing data outside of this perimeter.
The allegations prompted the DENR in South Dakota to take the unusual step of posting a statement on its website. It called the report's claims about the Big Stone site "untrue.''
The DENR stated that groundwater data collected at the site show no signs of contamination from the coal ash.
It stated that the glacial till in that area is naturally high in sulfates and minerals.
The high sulfate and metal levels are found up-gradient of the storage site, and those found at the site are not caused by the coal fly ash.
The Environmental Integrity Project "is incorrectly alleging groundwater impacts from a release from a brine pond that occurred more than 20 years ago are instead from the coal ash landfill," according to the DENR.
Peter Carrels, an organizer with the Sierra Club in Aberdeen, S.D., said during the press conference that the report clearly documents contamination due to the coal ash. He also said the contamination was continuing.
He called the 475-megawatt, coal-fired power plant "a sleeping giant in terms of pollution.''
Cris Kling, spokeswoman for Ottertail Power, the plant's owner, said the company is committed to good stewardship. She said the company does what regulators consider appropriate for a given situation.
There have been no findings of contamination at the site by regulators, or calls for changes in how the coal ash is managed, she said.
Kling also pointed out that the coal ash is stored as a dry ash.
The company does not store the coal combustion waste as slurry in ponds, a practice that has come under criticism nationally.