Mixing fresh water and Powder River Basin coal ash together yields a slurry full of contaminants at levels dangerous to human health, new research from Duke University found. The dusty waste produced when power plants burn coal is often disposed in dry landfills or ponds, including at several facilities across Wyoming.
Scientists at the Nicholas School of the Environment tested the toxicity of coal fly ash from several major coal basins, including the Powder River Basin. The preliminary results revealed that combining coal fly ash with water produces a concoction replete with hexavalent chromium, arsenic and other chemicals. In the study, Powder River Basin coal ash hosted the highest concentrations of hexavalent chromium. The contaminant is considered “carcinogenic to humans” by the World Health Organization.
“Our experiments suggest that when coal ash interacts with water as it will if it is spread on soil or buried in soil without protective liners — there is extensive mobilization of arsenic, selenium, and chromium, in the form of highly toxic hexavalent chromium,” stated Avner Vengosh, a professor of geochemistry and water quality at Duke University.
Vengosh presented his initial findings to the U.S. Environmental Protection Agency last week during a public hearing. The scientist cautioned the regulatory body to reconsider its proposed rollback of an Obama-era coal ash rule set to protect human health and water quality around the country. Since the introduction of coal ash controls in 2015, utility companies operating coal-fired power plants must carefully dispose of the waste product without harming the surrounding environment, water or communities.
The Trump administration announced it planned to consider petitions to relax some of these federal regulations in 2017. The EPA is currently working through the second phase of its proposed revisions to the rules. The changes, in part, slash regulations managing how companies handle and track piles of coal ash. It also considers ways to recycle coal ash for “beneficial” purposes before disposing the byproduct from burning coal.
“Today the Agency is proposing sensible changes that will improve the coal ash regulations and continue to encourage appropriate beneficial use,” EPA administrator Andrew Wheeler said in a July statement about the next phase of changes. “These proposed changes will further responsible management of coal ash while protecting human health and the environment.”
Weakening these coal ash provisions jeopardizes the quality of water wells, surface water, wetlands and residential drinking water, according to Vengosh.
“The amendments proposed by the EPA would allow the ‘beneficial’ placement of unlimited quantities of coal ash in the environment, potentially near drinking water wells, rivers and lakes, without any restrictions or safeguards,” Vengosh said in his testimony. “That could create countless new sources of leached contamination that will infiltrate into the subsurface and contaminate soil and water resources across the nation.”
The state’s largest utility company, PacifiCorp, recently investigated its coal ash ponds at the Jim Bridger and Naughton power plants in southwestern Wyoming. The results revealed groundwater contamination exceeded federal limits, prompting the utility to consider corrective measures.
Earlier this year, the Environmental Integrity Project, a nonpartisan organization researching pollution, published a report on the 100 million tons of coal ash generated by power plants each year. It ranked the Jim Bridger and Naughton plants as the third- and fourth-most contaminated facilities in the country, respectively.
For its part, PacifiCorp has emphasized its commitment to fully reclaiming the areas where contaminants exceed acceptable levels. It has also maintained the contamination does not compromise drinking water. In fact, the investigation prompted the company to solicit public input and take preparatory steps for long-term remediation efforts, according to Dave Eskelson, a spokesman for the utility company.
“We have reasonable confidence that the contaminants that we are mitigating do not pose an imminent risk to drinking water,” he told the Star-Tribune. “The company has long recognized that generating electricity has environmental impacts, but we know how best to mitigate contaminants, what works and why.”
The company held multiple public meetings this summer and solicited comments for cleaning up each of its coal-fired power plants in Wyoming and other states. According to Eskelson, PacifiCorp is now reviewing the comments and will decide on the best remediation strategy soon. He does not anticipate federal rule changes to immediately change how the company plans to mitigate the contamination found at its facilities.
Last week, the company also announced it would retire the majority of its coal-fired power plant units by 2030.
But Dalal Anne Aboulhosn, deputy legislative director of the Sierra Club, said she’s still concerned.
“These power plants are saying the contamination and pollution for now is on our property, not contaminating local areas, (but) how long does it take toxic chemicals to start leeching into neighborhoods and communities around those power plants and into the larger waterways that feed the economies of Wyoming?” Aboulhosn said. “We all know that these contaminants travel, this pollution travels, and that is what we’re worried about.”
The EPA held a hearing last week on the next phase of proposed changes to the 2015 coal ash rule and is now accepting public comments on the second phase of amendments. A virtual hearing will also take place Thursday.
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