BANGOR – Two environmental groups sued International Paper Co. on Tuesday, alleging its wastewater pollutes the Androscoggin River below its Jay mill in violation of state and federal water-quality standards.

The lawsuit was filed in U.S. District Court by the Natural Resources Council of Maine and the Natural Resources Defense Council.

The groups assert that Maine and federal laws require the mill to have a permit to discharge polluted wastewater into the river, but IP has not had one for two decades.

They say the last valid permit issued to the company was in 1985, and it was for just one year.

“The river belongs to the people of Maine and it is past time to clean it up,” said Brownie Carson, executive director of the Natural Resources Council of Maine, adding the suit asks IP to clean up the river and operate with a valid permit.

IP spokeswoman Fiona McCaul said Tuesday that the paper mill has been operating legally under federal, state and local rules.

“The last federal discharge permit we received was issued in 1985. Since then, we’ve voluntarily reduced our limits in cooperation with state, federal and local authorities,” McCaul said from her office in Jay.

On Monday, the Maine Department of Environmental Protection released a new draft discharge permit for the mill. The last state permit was issued in 1997, she said, and the last town and federal permits were issued in 2002 and 1985.

“All parties agree that water quality in the Androscoggin River needs continued improvement,” McCaul said. “How we get there should be determined by sound sceience and common sense, not emotions.”

The environmental groups say the Jay mill pours about 40 million gallons a day of wastewater into the Androscoggin.

They say pollution from the effluent violates water quality standards by lowering oxygen levels in river water so that native fish species, such as trout, cannot thrive.

The pollution also causes algae to form on the river in the summer, making the water unfit for swimming and further lowering dissolved oxygen levels, and affects creatures that live at the bottom of the river below the IP mill.

IP, the world’s largest paper company, announced a major restructuring plan earlier this month that could result in the sale of its two Maine mills.

As of December 2003, the company operated 36 pulp, paper and packaging mills and 132 converting and packaging plants among other facilities. It owns 8.3 million acres of land in the United States.

Hoping to boost profits and cut debt, the company is looking at selling $8 billion to $10 billion in assets, including millions of acres of forestland around the country, closing mills and possibly relocating its Connecticut headquarters.