A foundation that is one of the lead voices for more aggressive treatment of Duke Energy by the state has asked for a greater role in the cleanup at the company’s Mount Holly plant.

Tuesday, the Catawba Riverkeeper Foundation filed a document in the state’s Office of Administrative Hearings requesting a say in Duke’s challenge to a state permit. The permit in question would allow some wastewater to leak from the Riverbend Steam Station coal pond during cleanup.

That water could leak into the nearby Mountain Island Lake, a drinking water reservoir for about 1 million people in Gaston and Mecklenburg counties, according to the court filings.

The Riverkeeper and its legal representatives at the Southern Environmental Law Center distrust the state agency that oversees Duke’s cleanup because of past deals the agency has attempted with Duke, according to the filings.

With the office’s approval, Riverkeeper and SELC can argue in court, file more legal documents and participate in information gathering, the law center's senior attorney, Frank Holleman III, said. The Office of Administrative Hearings hasn’t said yet when it will rule on the filing.

Duke attorneys will not contest the motion, and the state agency, the Department of Environmental Quality, has no stance on the subject, according to the filings.

The draft for the permit right now allows certain amounts of chemicals like arsenic, mercury and aluminum to be expelled from the Riverbend coal ash pond.

Duke wants the permit changed in part so that more tests are allowed to see if an excess of chemicals found in the water is from Duke Energy or if they occur naturally, Duke spokeswoman Catherine Butler said.

Duke has employed a similar argument for why it’s not to blame for chemicals found in well water in Belmont. Groundwater that feeds into those wells may have picked up the chemicals from rocks and soil, not necessarily the nearby Allen Steam Station, Butler said.

The company has challenged the permit draft to make sure the final version is accurate, she said. This permit will be a model for closing all 14 coal ash ponds in the state.

“This is another attempt by SELC to grandstand,” Butler said. “We’re not surprised that they would want to intervene.”

Duke retired the Riverbend plant in 2013 and has until 2019 to move the ash, left over from burning coal for energy.

The Allen Steam Station in Belmont has one inactive coal ash pond and one active pond. The state is still deciding how long Duke has to clean up the site and whether the company has to move the ash or can it cap it in place with a five-layer covering.

Belmont residents previously told by the state not to drink their well water were told earlier this month the water is OK to drink and actually has lower concentrations of potentially dangerous chemicals than does some city water.

Duke, based in Charlotte and known as the largest utility company in the country, was ordered by the state in 2014 to clean up its North Carolina ash ponds after a spill into the Dan River by Duke’s plant in Eden.

Gov. Pat McCrory worked for Duke Energy for about 30 years before getting elected to office.