The pressure from Democrats underscores the political delicacy of White House energy policies. The Obama administration is seeking to show that it backs oil-and-gas drilling while also emphasizing its efforts to expand environmental safeguards.
Fracking involves high-pressure injections of water, chemicals and sand into rock formations in order to open up seams that enable trapped natural gas and oil to flow.
An Interior official defended the rule, noting the disclosure after the fracking has occurred will still enable investigators to trace the source of contamination if waters are polluted.
“It is just as effective in creating a ... ‘fingerprint’ in case of any type of incident,” the official said. The Interior official said that as the department was crafting the proposal, it became clear that plans to require chemical disclosure ahead of fracking would have created delays in gas drilling, but would not have boosted public confidence.
Fracking is enabling a gas-production boom in many states but bringing concerns about water pollution alongside it, and the increased drilling is also worsening air pollution in some regions.
The proposed rule from Interior's Bureau of Land Management also contains requirements on oil-and-gas well integrity to verify that fluids from the fracking process aren’t escaping into nearby water supplies, and requirements for management of large volumes of so-called flowback water.