Accusing Lehigh Southwest Cement of dumping thousands of gallons of untreated wastewater containing dangerous toxins into Permanente Creek daily, the Sierra Club filed a lawsuit in federal court on Monday, asking that the company be forced to stop, as well as pay multi-millions in fines for violating the Clean Water Act.

“After years of unchecked pollution, it’s time for Lehigh to clean up its act,” said Gary Latshaw of the club’s local Loma Prieta Chapter in a statement. “Its refusal to control its water pollution has no place in the heart of Silicon Valley. We intend to enforce the Clean Water Act to restore the health of this precious public stream in Santa Clara County.”

The club contends that high levels of selenium and other toxins from the cement plant and quarry—as recorded by the company’s own consultants—are endangering wildlife and damaging the creek, as well as percolating into underground aquifiers used for drinking water. Permanente Creek was listed as an "impaired" water body by the EPA in November 2010.