With both tight gas sands and oil shale development emerging in the state, a California legislator has introduced a bill (AB 591) seeking to require public disclosure of any chemicals used in oil/gas hydraulic fracturing (fracking).

Environmental groups in the state are supporting the bill as a means of providing more transparency in the energy production sector. The measure is authored by Assemblyman Bob Wieckowski, chairman of the lower house's Environmental Safety and Toxic Materials Committee.

Wieckowski said new technologies and drilling practices, such as fracking, now allow oil companies to access previously unavailable oil/gas reserves in California. "While industry is adapting to these new practices quickly and with a lot of investment, state regulators are falling behind," a spokesperson for the lawmaker said.

AB 591 passed its first legislative hurdle in late April, clearing an initial committee vote by 5-3. A staff attorney with Environment California, Pamela King Palitz, warned that there are "several points in the fracking process with potential for contamination to our precious water supply."

Wieckowski said tight gas sands in Northern California and "the richest oil shale deposits in the United States" are located in Central and Southern California. And the lawmaker's contention is that they are "generating a lot of interest among oil/gas producers" who would use fracking more frequently to extract them.

Backers of the legislation also point to California's ranking as the fourth largest oil/gas producer in the United States. The legislation will allow the state to "catch up" to what is going on nationwide in the industry.

"AB 591 will provide state regulators with more tools to stay on top of what is actually happening in the field," said Wieckowski, who wants any chemicals injected in wells to be divulged to both regulators and the public. "This bill will prevent the kind of calamities that we are hearing about from fracking in Texas, Wyoming, Pennsylvania and elsewhere."

The bill already has gained the support of the Los Angeles Times editorial board, which called the measure a "modest step."