Cupertino Quarry Owner Begins $25 Million Permanente Creek Cleanup Effort

The owners of a large South Bay quarry and cement plant broke ground this week on a massive effort to remove tons of toxic waste from a creek that flows from the Santa Cruz Mountains into the San Francisco Bay.

Heidelberg Materials, which owns the facility in the hills west of Cupertino, is required under a settlement with the Sierra Club to restore nearly two miles of the most contaminated stretches of Permanente Creek by 2030.

The undertaking comes 14 years after the environmental group sued the Lehigh Southwest Cement company, the plant’s previous owners. The lawsuit accused the company of illegally discharging selenium, nickel and other toxic metals into the creek, in violation of the federal Clean Water Act.

The U.S. Environmental Protection Agency in 2015 also slapped the company with more than $2.5 million in fines for water quality violations and forced it to spend another $5 million on a new wastewater treatment plant to protect the creek from toxic discharges.

As part of the settlement, Heidelberg has agreed to restore roughly 9,000 feet of the creek over a six-year period, at an estimated cost of $25 million, the company said.

The project includes the removal of thousands of tons of contaminated sediment and mining infrastructure. The company has also committed to replanting native vegetation, building pools for trout and stabilizing creek banks, among other restoration efforts.

Mike Ferreira, chair of the Sierra Club’s Loma Prieta chapter, said the restoration project is long overdue and will finally address “decades of toxic pollution that residents have been forced to live with.”

“We are relieved that we have finally gotten to this point,” he said.

Permanente Creek flows past the facility before heading north through Mountain View and Los Altos as it makes its way to the bay. The waterway provides important habitat for rainbow trout and California red-legged frogs, which are listed as threatened under the Endangered Species Act, the Sierra Club said.

“It’s an exciting day, and much anticipated for a very long time,” said Santa Clara County Supervisor Margaret Abe-Koga, whose district encompasses the creek. “Today was a milestone, but it will be many years in the making, and it will be important for community members to continue to be engaged in the process.”

Heidelberg, a German company with U.S. headquarters in Texas, signed an agreement in 2023 with the Santa Clara County Board of Supervisors to wind down operations at its nearly century-old cement plant, which has long been one of the region’s largest sources of air and water pollution.

David Perkins, a Heidelberg spokesperson, said the creek project will improve conditions on dozens of acres around the creek bed, and “exemplifies” the company’s commitment to delivering on its restoration promises.

Calling the effort “ambitious in scope,” he pledged his company would see it through to completion.

“Our work continues, and we’re committed to staying engaged and responsive over the long term,” Perkins said in a statement.

But Reed Zars, the lead attorney representing the Sierra Club, said the company had been “a reluctant defendant” in the prolonged legal battle over the creek cleanup, and is only now taking action after being compelled to do so.

Nonetheless, he said, the beginning of the restoration effort marks a significant environmental victory.

“Where we are now is to bring that creek back to its natural state,” he said. “It’s just very exciting for us to see it now take place on the ground.”

Zars noted that the fight against the company was largely driven by community members involved with the Sierra Club, not by local and federal regulators, who he said fell short of adequately holding the company accountable.

“We brought the action even though the California Water Board could have, even though EPA could have,” he said. “But that hadn’t happened.”