A group of California lawmakers wants the federal government to investigate hydraulic fracturing off the California coast.
The Associated Press recently reported that regulators have allowed fracking in the Santa Barbara Channel at least 12 times in the past and approved a new project this year. The work has been done in coastal waters where new oil leases have been banned after a 1969 oil spill.
The letter expressed "extreme concern" about the practice, which involves pumping sea water, sand and chemicals beneath the seabed.
Regulators have exempted fracking fluids from the nation's clean water laws, allowing companies to release them in the ocean without a separate environmental review.
The oil industry insists fracking is safe and has been done for decades in California with no evidence of environmental harm.