LONG BEACH -- The oil production technique known as fracking is more widespread and frequently used in the offshore platforms and man-made islands near some of California's most populous and famous coastal communities than state officials believed.
In waters off Long Beach, Seal Beach and Huntington Beach -- some of the region's most popular surfing strands and tourist attractions -- oil companies have used fracking at least 203 times at six sites in the past two decades, according to interviews and drilling records obtained by The Associated Press through a public records request.
Just this year in Long Beach Harbor, the nation's second-largest container port, an oil company with exclusive rights to drill there completed five fracks on palm tree-lined, man-made islands. Other companies fracked more than a dozen times from old oil platforms off Huntington Beach and Seal Beach over the past five years.
Though there is no evidence offshore hydraulic fracturing has led to any spills or chemical leaks, the practice occurs with little state or federal oversight of the operations.
The state agency that leases lands and waters to oil companies said officials found new instances of fracking after searching records as part of a review after the AP reported this summer about fracking in federal waters off California, an area from three miles to 200 miles offshore. The state oil permitting agency said it doesn't track fracking.
As the state continues its investigation into the extent of fracking -- both in federal waters and closer to shore -- and develops ways to increase oversight under a law that takes effect in 2015, environmental groups are calling for a moratorium on the practice.
"How is it that nobody in state government knew anything about this? It's a huge institutional failure," said Kassie Siegel, an attorney with the Center for Biological Diversity. "Offshore fracking is far more common than anyone realized."
Little is known about the effects on the marine environment of fracking, which shoots water, sand and chemicals at high pressure to clear old wells or crack rock formations to free oil. Yet neither state nor federal environmental regulators have had any role in overseeing the practice as it increased to revitalize old wells.
New oil leases off the state's shores have been prohibited since a 1969 oil platform blowout off Santa Barbara, which fouled miles of coastline and gave rise to the modern environmental movement. With no room for physical expansion, oil companies instead have turned to fracking to keep the oil flowing.
The state launched an investigation into the extent of offshore fracking after the AP report in August. California officials initially said at the time there was no record of fracking in the nearshore waters it oversees. Now, as the State Lands Commission and other agencies review records and find more instances of fracking, officials are confused over who exactly is in charge of ensuring the technique is monitored and performed safely.
"We still need to sort out what authority, if any, we have over fracking operations in state waters; it's very complicated," said Alison Dettmer, a deputy director of the California Coastal Commission.
Nowhere is the fracking more concentrated than in Long Beach.
The city's oil arrangement stems from a deal drawn up in 1911, when California granted the tidelands and other water-covered areas to the city as it developed its harbor. When oil was discovered in the 1930s, the money started coming in.
Long Beach transferred $352 million of $581 million in profits to state coffers in fiscal year 2013 from onshore and offshore operations, according to the city's Gas and Oil Department.