The suit filed in U.S. District Court in Reno on Monday seeks a minimum of $5 million on behalf of at least 100 residents in the rural town of Yerington where the old Anaconda copper mine opened in 1941.
The plaintiffs say the wells they once used for drinking water are polluted with uranium, arsenic and other metals in a plume of groundwater that slowly has migrated off of the site that covers 6-square miles - an area equal to the size of about 3,000 football fields - about 65 miles southeast of Reno.
The lawsuit says that even after whistleblowers started to publicize previously secret records documenting the dangers, the corporations refused to cooperate with state and federal regulators trying to clean up the radioactive and other hazardous waste the past 10 years.
"They destroyed the water supply to this community and now it's time to clean it up. It's time to get the contamination off these people's land and out of their wells," said Steven German, one of the lawyers who filed the lawsuit on behalf of the residents.
"A mother should not have to tell her child they can't turn on the spigot because their water is dangerous. That is not acceptable in this country," he told The Associated Press on Tuesday.
The lawsuit said the companies knew or should have known that their discharge of toxic and hazardous materials would pollute neighboring properties, air, water, groundwater and the surrounding environment. It said they have 'intentionally allowed toxic and hazardous substances to enter and remain on" the neighbors' land.
"Despite their knowledge of the serious health and environmental effects associated with exposure to toxic and hazardous substances and despite orders and warnings form health and environmental regulators, (BP and ARCO) intentionally masked the true extent of the contamination, thereby enabling (them) to avoid taking all appropriate steps to properly remediate the toxic and hazardous substances or to mitigate the dangers created by their release, discharge, storage, handling, processing, disposal of and dumping of toxic and hazardous substances," the suit said.
Tom Mueller, a spokesman for BP America, said Tuesday evening that company officials have not had a chance to review the lawsuit and had no immediate comment.
Fueled by demand after World War II, Anaconda produced nearly 1.75 billion pounds of copper from 1952-78 at the mine that runs along U.S. Highway 95 in the Mason Valley, an irrigated agricultural oasis in the area's otherwise largely barren high desert.
The U.S. Environmental Protection Agency has determined over the years that uranium was produced as a byproduct of processing the copper and that the radioactive waste was initially dumped into dirt-bottomed ponds that - unlike modern lined ponds - leaked into the groundwater.
Officials for BP and its subsidiary Atlantic Richfield, which bought Anaconda Copper Co. in 1978, have provided bottled water for free to any residents who want it over the past few years. But they have insisted that uranium naturally occurs in the region's soil and, until recently, they argued there was no way to prove that a half-century of processing metals there was responsible for the contamination.
However, a new wave of EPA testing first reported by The Associated Press in November 2009 found that 79 percent of the wells tested north of mine have dangerous levels of uranium or arsenic or both that make the water unsafe to drink.
"You now have evidence of mine-impacted groundwater," Steve Acree, a highly regarded hydrogeologist for the EPA in Oklahoma brought in to examine the test results, told AP at the time.
One monitoring well a half mile away had levels of uranium more than 10 times the legal drinking water standard. At the mine itself, wells tested as high as 100 times the standard in an area where ore was processed with sulfuric acid and other toxic chemicals in unlined ponds.
Though the health effects of specific levels are not well understood, the EPA says long-term exposure to high levels of uranium in drinking water may cause cancer and damage kidneys.