Grass Valley and the Newmont Mining Corporation remain locked in a legal struggle, neither willing to claim ownership or financial responsibility for the hundreds of thousands of gallons of contaminated water that flow into the city's wastewater treatment plant each day.

The mine discharge was discovered in 2000 as the wastewater treatment plant was undergoing expansion, Public Works Director Rudi Golnik said. The seepage was always considered a natural spring until its orange discoloration spurred workers to investigate its source.

They discovered the water stemmed from the vast underground network of tunnels leftover from the Northstar Mine, Golnik said. The city entered negotiations with Newmont, which has owned the mine since the 1930s.

After failing to agree how to stem the flow and split the costs, Grass Valley took the company to federal court. The case remains unresolved.

A Newmont spokesman said the company is working to settle the dispute "expeditiously."

In the meantime, the city is attempting to stop the contaminated discharge.

The city's most recent plan, an underground plug that would block the flow, was not accepted by the state's Regional Water Quality Control Board because the board feared the contaminated water would surface elsewhere.