A case brought by a coalition of environmental groups against the Tennessee Valley Authority over coal ash byproduct contamination stemming from its Gallatin generating plant is set to begin in federal court Jan. 30.

The case, filed by the Southern Environmental Law Center, or SELC, in the U.S. District Court for the Middle District of Tennessee alleged that for more than 50 years, toxic coal ash pollution has been leaking from the plant into the Cumberland River, a source of drinking water for over one million state residents.

A recent review of groundwater monitoring wells showed that "areas scattered all over the Gallatin Plant contain arsenic at levels well above [the U.S.] EPA's Maximum Contaminant Level; one area was as high as twenty times the EPA level," according to SELC.

In November 2014, SELC announced its intention to sue TVA on behalf of the Tennessee Clean Water Network and Tennessee Scenic Rivers Association.

But that action was effectively blocked when Tennessee Attorney General Herbert Slatery III and the Tennessee Department of Environment and Conservation filed an enforcement action in January 2015. They alleged that TVA violated the Tennessee Water Quality Control Act, the Solid Waste Disposal Act and its permit from the EPA that allows a certain amount of effluent discharge from a single point into the nearby Cumberland River.

Nevertheless, SELC filed a federal lawsuit against TVA in April 2015 over issues it said were not addressed by the state's lawsuit.

The utility and the state of Tennessee in January 2016 agreed to a temporary injunction in the state's case. That injunction stated it was not intended to have any effect on the progression of the federal suit filed by SELC, but TVA immediately filed it in federal court in an effort to get that case dismissed, according to SELC.

In September 2016, part of the suit was dismissed by District Court Judge Waverly Crenshaw Jr. because it overlapped with the state's case. Crenshaw reasoned that dismissing the entire federal case would "treat the state's decision to proceed narrowly as an absolute bar on citizen enforcement against violations that the state complaint does not even consider," and would "run counter to the well-recognized role of citizen suits in supplementing government authority under the [Clean Water Act]."

Additionally, according to SELC, the state attorney general's office recently demanded that TVA turn over water quality data to TDEC, stating that withholding the data was in violation of state law. SELC also accused TVA of withholding information on a recently discovered sinkhole at the Gallatin site, calling the storage system "unstable." Neither the well data nor the new sinkhole was disclosed in court filings related to the case, SELC said.

TVA spokesperson Scott Brooks said in an email that the company does not think it is appropriate "to try the case in the media," but he asserted that the utility is committed to environmental stewardship and is acting in the financial interests of its 9 million customers, as mandated.

"The plaintiffs appear to have a much more narrow focus," Brooks said, noting that TVA is investing billions of dollars in the safe handling and storage of coal ash and other coal combustion residuals, or CCRs, including at Gallatin.

TVA has moved from wet to dry coal ash storage and is in compliance with the federal CCR rule and its state and federal permits, according to Brooks. "We intend to let the facts, including data collected, tell our story," he said, adding that long-term storage of legacy CCR at the plant has not yet been decided, pending results of court action.

Brooks explained that the TVA is conducting an extensive environmental investigation CCR at Gallatin "to fully understand the geology and groundwater at the site," and those results are being shared with the state. "Decades of data available to the public confirms there is no impact to drinking water sources from TVA operations, including the Cumberland River," he said.

The U.S. EPA's final rule on CCR set requirements for coal ash sites at active power plants, including monitoring groundwater, keeping waste sites away from water bodies and mandating new reporting from utilities. The impetus for the rule came from a 1.1 billion gallon coal ash spill at TVA's Kingston plant in 2008.