After decades of oil drilling, California has released draft regulations for hydraulic fracturing, or fracking.
The proposed rules were posted online Tuesday by the state's oil regulators. California currently oversees oil well construction but it has not required disclosure of fracking practices.
Under the draft regulations, operators would have to name the chemicals used in fracking and they would have to test their wells to ensure they can withstand the drilling process.
Fracking has been quietly going on in several counties including Los Angeles, Kern, Monterey and Sacramento to extract hard-to-reach oil. Other states use the technique to recover natural gas.
Environmentalists worry fracking can contaminate groundwater and pollute the air. The industry has said it has been safely used for decades.
Read the draft regulations: