Think the “Erin Brockovich carcinogen” is only found in the bleached-out landscape of Southern California?

Think again.

Hexavalent chromium is a byproduct of coal-fired power plants across the country—including We Energies’ Pleasant Prairie plant in Kenosha—according to a new report analyzing data from the U.S. Environmental Protection Agency (EPA).

The report stated that the Pleasant Prairie plant’s coal ash contained 3,443 parts per billion (ppb) of chromium, which is 34.3 times above the federal drinking water standard and 172,150 times above a more stringent standard recently proposed in California.

Figures from the EPA have also identified two sites in Wisconsin that have chromium-contaminated groundwater from coal ash—the Dairyland Power Cooperative ash disposal pond in Cassville (an unlined pond) and the Lemberger Landfill (an unlined landfill) in Manitowoc County.

Federal regulators have stated that almost all of the chromium that leaches from coal ash is hexavalent chromium, a cancer-causing form of the heavy metal chromium.

Safe Disposal Is Key

While hexavalent chromium wasn’t found in the groundwater near the Pleasant Prairie site, it has the potential to leak into the groundwater, argues a new report by Earthjustice, Physicians for Social Responsibility and the Environmental Integrity Project.

“What we’re pointing out is that the potential for contamination of groundwater, surface water, exists if that ash isn’t disposed of safely,” said Earthjustice’s Lisa Evans, the report’s author.

Brian Manthey, spokesman for We Energies, said that the EPA’s tests don’t accurately represent the amount of chromium in the plant’s landfill, which has a 5-foot recompacted clay liner to prevent contaminants from leaking into groundwater.

Manthey said the utility’s tests—conducted by an outside, independent laboratory—show chromium levels in the landfill to be far lower than the EPA’s lab results. Chromium in the lighter fly ash is 150 ppb; its heavier bottom ash has 3.5 ppb of chromium.

Almost all of the plant’s coal ash is recycled into other products such as roadbed fill or concrete as part of a state Department of Natural Resources (DNR)
beneficial use program.

Philip Fauble, the DNR’s beneficial use coordinator, said that the agency has been aware of the presence of chromium in coal ash for years and that it tests coal ash and the groundwater near landfills for toxins. He said the Pleasant Prairie site is within the state standards for chromium.

“We think the material is being managed properly,” Fauble said.

Earthjustice’s Evans said that Wisconsin’s recycling program is commendable, but that not all of the coal ash in the state is safely reused or stored in lined landfills.

“There is a lot of ash buried in Wisconsin that needs careful monitoring,” Evans said. “Before those aggressive recycling programs were introduced, there was a lot of unsafe disposal of ash in unlined pits. And those dumps may come back to haunt the communities that live near them and should be treated as a continuing threat. Coal ash is a material that changes over time. It will keep leaching.”

Drinking Water a Concern

Hexavalent chromium is a highly toxic form of chromium, a naturally occurring heavy metal. Besides coal plants, the toxic chemical is discharged from steel and pulp mills and metal plating and leather tanning facilities, a 2010 study by the Environmental Working Group stated.

Hexavalent chromium has long been known to cause cancer when inhaled.

But more recently, hexavalent chromium-laden drinking water was found to cause cancer in lab animals, according to tests done by the U.S. Health and Human Services.

As a result, state regulators in California recently proposed lowering the state’s drinking water standard for the toxin to 0.02 parts per billion (ppb), well below the federal standard of 100 ppb.

A study released in December 2010 showed that hexavalent chromium was found in the drinking water of Milwaukee and Madison. Milwaukee’s tap water, even after it’s been treated, had 0.19 ppb, far higher than California’s proposed standard, but much lower than the federal standard.

Earthjustice’s Evans said the federal government should update its safety standard, which was set in 1991, before the dangers of ingested hexavalent chromium were identified.

She said that coal ash as a potential source of hexavalent chromium contamination of groundwater is being overlooked by the EPA as it weighs new regulations of coal ash.

“Now there is the knowledge that hexavalent chromium can cause cancer when ingested and that the amount that it can do so is an amount that is lower than the drinking water standard,” Evans said. “That’s what the EPA is not looking at with their risk assessment.”