A lawsuit filed against Reliant Energy Inc. alleges that its Conemaugh Generating Station in Indiana County is in continuous violation of a federal Clean Water Act discharge permit despite the company's side agreement with the state that allows the pollution.

The suit filed in U.S. District Court in Pittsburgh Tuesday by PennEnvironment states that the 37-year-old coal-fired power plant discharges 3 million gallons of wastewater a day containing selenium, manganese, aluminum, boron and iron in concentrations that frequently exceed pollution limits set by the state to protect water quality in the Conemaugh River.

The state Department of Environmental Protection agreed not to enforce those pollution limits until 2011 because water pollution control technology can't remove the pollutants created by air pollution controls installed in 1994 and 1995.

"At some point, people simply have to stand up and take action themselves to protect the quality of their water," said David Masur, director of PennEnvironment, a statewide nonprofit environmental advocacy group. "People living along the Conemaugh River have reached that point, and fortunately the Clean Water Act empowers them to enforce the law against persistent violators like Reliant."

Mr. Masur said that the discharge of the pollutant metals may impede efforts to restore the Conemaugh River, which has a long history of pollution from acid mine drainage and industrial discharges.

The DEP has designated the Conemaugh an "impaired water body" because of excessive concentrations of metals. Selenium, in particular, is highly toxic to fish and waterfowl, and the harmful effects of many of the metals discharged by Reliant can be enhanced by acidic water.

Reliant, which jointly owns the Conemaugh station with seven other entities and operates the facility on behalf of the owners, issued a statement saying it is "committed to operating its facilities in compliance with all environmental law and regulations" and is in compliance with the wastewater discharge agreement it has with the state.

PennEnvironment is asking the court to stop the polluting discharges that Reliant's own monitoring reports show occurred on about 200 days since February 2005. The court can also impose a fine of $32,500 for each of the violations.