By Bob Egelko

California and environmental and tribal groups sued the Trump administration in San Francisco federal court Wednesday seeking to enforce Obama administration regulations of hydraulic fracturing, or fracking, for oil and gas wells on hundreds of millions of acres of federally managed lands.

Fracking sends blasts of water, sand and chemicals into wells to crack underground rocks and release oil and natural gas. It has greatly increased well production but also poses a risk of water and air pollution and greenhouse gas emissions.

Rules announced by the Obama administration's Interior Department in 2015, after five years of review, would require operators to disclose chemicals used in fracking on federal and tribal lands and would set standards for well construction, water protection and waste storage.

But a federal judge in Wyoming blocked the regulations from taking effect, in a suit by oil and gas companies and several states, ruling that the federal government lacked authority to regulate fracking. President Trump ordered repeal of the never-enforced rules in March, and his Bureau of Land Management took formal action to remove them in December.

The bureau said the Obama administration's action "unnecessarily burdens industry with compliance costs and information requirements" and that states and Indian tribes can adequately manage the practice. The bureau also said its repeal would have no significant environmental impact.

But in separate lawsuits Wednesday, California Attorney General Xavier Becerra and environmental advocates said the administration was ignoring its legal responsibility to protect public lands.

Federal law requires the Bureau of Land Management to manage public lands in a way that protects "environmental, air and atmospheric (and) water resource" values, and the bureau offered no explanation of how repealing the fracking regulations would fulfill those obligations, Becerra said in his lawsuit.

He said the claim of no environmental impact ignores ample evidence that unregulated fracking increases air and water pollution, adds to climate change, threatens rare animal and plant species and adds to the risk of earthquakes.

"The Interior Department's own factual record shows that the risks to our health and environment are real," Becerra said in a statement.

Attorney Michael Freeman of Earthjustice, which sued on behalf of the Sierra Club, the Center for Biological Diversity and other environmental and tribal groups, said the repeal was "another case of the Trump administration putting our public lands and water at risk to pad the bottom line of the oil and gas industry."

There was no immediate comment from the Trump administration.

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