Legislation to comprehensively regulate hydraulic fracturing, and now other methods of stimulating oil and gas production in California, cleared the Assembly Natural Resources Committee July 1. \tSB 4, authored by Sen. Fran Pavley (D-Agoura Hills), breezed through the panel on a 6-3 vote after the Los Angeles area Democrat agreed to incorporate minor technical amendments. They clarify that the Division of Oil, Gas & Geothermal Resources will collect fees needed from drillers to fund the multiagency regulatory regime outlined in measure. The amendments also aim at enhancing groundwater monitoring required by the bill. \t\u201cIt\u2019s a comprehensive approach to regulating fracking, acid stimulation, and other forms of well stimulation in California,\u201d Pavley told the committee. \tConcerns about fracking and other hydrocarbon drilling stimulation techniques range from the possibility that chemicals injected down wells could contaminate groundwater, to emissions of pollution to the air and the unknowns about the fate of toxic waste produced at drilling sites. \tTo address those concerns, the division has been working to develop regulations, but many community leaders, lawmakers, and environmentalists have criticized the process as too slow and the rules under consideration as inadequate. \tThe division of oil and gas \u201cneeds direction,\u201d said Bill Allayaud, Environmental Working Group director of California government affairs. \tPavley said the division\u2019s draft rules \u201cshould be stronger\u201d and that her legislation will insure they are. \tHer bill comes as the division is developing its own regulations to cover the practice of fracking in advance of what\u2019s expected to be a major shale oil play in the San Joaquin Valley and Los Angeles area. Combined, those two areas are considered the largest shale oil resource in the nation, bigger than the Bakken formation, centered in North Dakota. \tThe two California shale formations\u2014known as the Lower Monterey in San Joaquin Valley and the Santos around Los Angeles\u2014are estimated to hold 15 billion barrels of oil, which amounts to two-thirds of the nation\u2019s known shale oil resources, according to a committee staff report. That\u2019s enough oil to meet the state\u2019s needs for 21 years, according to the committee document. \tBefore being presented to the committee, Pavley\u2019s bill was broadened to cover well stimulation beyond traditional fracking, in which fluid is injected under high pressure down wells after they are drilled to split the rock and create channels through which hydrocarbons can flow to the ground. \tThe Senator told the committee this is necessary because 80 percent of the wells drilled into the shale formations may rely on acid stimulation, according to testimony given by oil and gas industry representatives at a recent hearing. \tThat technique involves pumping acid down into wells to dissolve the limestone, dolomite, and calcite that act like cement between the grains of sediment in hydrocarbon bearing shale formations. \tUnder Pavley\u2019s bill, the division would have to establish a permitting system by 2015 for well drilling involving stimulation techniques. Groundwater monitoring before and after drilling would be required to detect whether the oil and gas operations caused contamination. \tIn addition, the measure would require an independent study of well stimulation processes to outline potential threats and identify ways to address them. Oil and gas drillers would be required to post on a public website the ingredients of various fluids used in stimulating wells, though not the precise formulas, which are considered trade secrets. \tWaste from the drilling operations would have to be tracked to show its final disposition. \tFinally, among other requirements, the division would have to coordinate in developing and enforcing regulations with other state agencies in charge of air pollution, water quality, and toxic waste management.