Electric utilities are disputing a report which—using the utilities’ own data— says at least 91% of the nation’s coal ash facilities are polluting groundwater.

Using data made available under the 2015 Coal Ash Disposal Rule, the Environmental Integrity Project found 242 of the 265 coal-fired plants showed unsafe levels of multiple pollutants around coal ash disposal sites. The report was based on information drawn from the the sites’ groundwater monitors. Pollutants included arsenic, lithium and sulfate. Coal ash is a byproduct of burning coal for power generation.

But Jim Roewer, executive director of the Utility Solid Waste Activities Group, the trade group responsible for addressing solid and hazardous waste issues on behalf of the utilities, says the data was incorrectly analyzed.

“Ninety-one percent is a gross exaggeration, he says. “They used very simplistic and inappropriate data,” including health-based standards that don’t apply to the groundwater around the facilities.

And, Roewer adds, the data is evidence that utilities are beginning to address the pollution problems at the sites as called for in the 2015 law. “This whole process really is working as the Obama administration intended it to work,” he said. A utility exceeding groundwater protection standards must develop a remedy to address the pollution, he said.

The Environmental Integrity report points out that 70 plants are required to complete cleanup plans in 2019, “But at most sites, we still do not know whether or how the owners plan to remediate any onsite contamination.”

Remediation is occurring at the Tennessee Valley Authority’s Allen Plant, five miles southwest of downtown Memphis near the Mississippi River. The Environmental Integrity report says arsenic has leaked into the groundwater at 350 times the safe levels and lists the site as one of the top 10 offenders.

Cleanup is expected to begin this year at the site, a TVA spokesman says. “TVA is conducting a remedial investigation on the arsenic exceedances found in the shallow aquifer and has provided [Tennessee Dept. of Environment and Conservation] with a recommended interim corrective action (pump and treat) to address the environmental impacts. Field work on the corrective action is expected to begin in 2019,” said Scott Brooks, a TVA spokesman via email. Work will begin once the design for interim solution is complete. Stantec is designer for the project.

Still, Brooks said, TVA doesn’t agree with the premise of the report. There’s nothing definite linking the high levels of arsenic to the coal ash, he maintains, because the numbers in the report from 2017 were “multiple times higher than what we normally see from coal ash.” More recent 2018 testing doesn’t reflect the higher levels of contamination.

Environmental Integrity says recent studies show a direct connection between the contaminated shallow aquifer and the deeper Memphis aquifer, creating a threat to drinking water for Memphis residents. However, Brooks says drinking water is not affected at Allen or any of TVA’s coal sites. “Repeated testing has found no arsenic in the Memphis Sand Aquifer, which is the source for Memphis drinking water,” he says.

The Coal Ash rule, which came about after a 2008 spill of 1.1 billion gallons of coal ash slurry at TVA’s Kingston Fossil Plant in Tennessee operates under a self-implementing rule, meaning that the utility self reports groundwater information and then takes appropriate action on its own.

Among other things, the Environmental Integrity report calls on the Environmental Protection Agency to require the excavation of all dumps within five feet of water.

Even without such regulations, public sentiment is pushing utilities to excavate coal ash from unlined pits and place it in lined pits, says, Frank Holleman, senior attorney for the Southern Environmental Law Center, which has successfully sued and supported public efforts toward excavation.

“Advocacy and local governments have changed the minds of utilities,” he says. The Virginia Assembly last month approved a bill that requires Dominion to remove the coal ash from storage in the Chesapeake Bay watershed.

“It’s a total change and it’s a great opportunity for the engineering profession to help these utilities design well-built and well located landfills to contain this ash,” he says. “Good engineering is essential.”