A prominent environmental group accused state oil regulators Wednesday of failing to comply with public disclosure rules contained in an interim version of California's new fracking law.

The accusations are part of the Center for Biological Diversity's efforts to build support for a proposed fracking moratorium that on Wednesday cleared the state Senate Environmental Quality Committee. The legislation, Senate Bill 1132, would disproportionately impact Kern, by far California's top oil-producing county.

In a letter to Gov. Jerry Brown, the CBD said legally required data on recent frack jobs around the state is incomplete or absent from a public website maintained by the state Division of Oil, Gas and Geothermal Resources.

"Clearly, 'mandatory' reporting requirements are failing, and the public is left in the dark with regard to a large portion of well stimulation information," the letter stated.

The group asked the governor to fine oil field operators who have neglected to provide the state with required data, investigate why fracking information was not posted on time, and impose an immediate moratorium on fracking and other oil well stimulation techniques.

The letter did not specifically mention frack jobs in Kern County.

Jason Marshall, a senior state regulator in Sacramento, blamed unnamed oil field operators for neglecting to provide the state with timely and complete information about frack jobs -- or, in some cases, failing to conduct the required chemical testing.

While regulators prod oil companies to do better, he said in an email, the state has chosen to withhold required information rather than post incomplete reports.

"By and large, operators have reported information required and been responsive to department requests to correct errors, provide more specific information or conduct further chemical testing to complete the required disclosure," wrote Marshall, chief deputy director of the state Department of Conservation, DOGGR's parent agency.

Hydraulic fracturing has become a common practice in Kern since its local introduction decades ago. It pumps water, sand and sometimes toxic chemicals to open access to oil and gas reservoirs. The CBD and other groups claim the practice threatens groundwater and air quality, while the oil industry maintains there is no evidence fracking has caused pollution.

The CBD's letter said that in addition to delaying public disclosures on at least 47 frack jobs in the state, DOGGR posted some well stimulation reports that lacked required data on things like where the water for individual frack jobs originated.

The letter also said DOGGR's website had no information on 57 instances of acidization -- a technique similar to fracking that uses acids to make underground formations more porous -- the group believes took place earlier this year in Southern California. Similarly, it said the site has no information on any "gravel packing" operations, which it claimed uses dangerous chemicals and is regulated under the fracking law.

But Marshall, the state regulator, said gravel packing and the instances of acidization referred to by CBD actually represented routine well maintenance work not regulated under Senate Bill 4, the fracking law that took effect Jan. 1.