California state Sen. Fran Pavley, a Democrat, pushed a measure through to regulate hydraulic fracturing, or fracking, and Gov. Jerry Brown said he'd sign the measure, The Los Angeles Times reported.
Pavley said in a statement the measure would require permits for fracking.
"It is in the interest of all Californians to monitor and regulate these practices," she said in a statement Wednesday. "Ultimately the oil industry, not the public, should be held accountable for the costs of these activities."
Oil companies in California are targeting the Monterey shale deposit, which Pavley said holds an estimated 15.4 billion barrels of recoverable oil.
The Natural Resources Defense Council, California League of Conservation Voters, Clean Water Action and Environmental Working Group said they no longer supported the measure. They said the oil industry's leverage weakened the measure's intent.
"Californians deserve to have their health and drinking water sources protected from oil and gas development," Miriam Gordon, California Director of Clean Water Action, said in a statement.