US Interior Secretary Sally Jewell drew on her experience as a former oil-industry engineer to defend proposed federal regulation of hydraulic fracturing for oil and gas on publicly owned land.

Testifying to the House Natural Resources committee July 17, Jewell faced criticisms from Republican lawmakers, who said the department’s proposed rule on fracing will lead to unnecessary production delays.

The rule would set minimum standards for well construction, disclosure of chemicals, and water management when fracing is used on federal lands.

Lawmakers told Jewell that state regulators best know the local geology and the federal government should leave the regulation to them.

“The states vary in their understanding of hydraulic fracturing,” Jewell said. Some states, such as Wyoming, have strong rules, while “in many cases, the state rules don’t exist or are out of date.”

Further, no matter where a well is drilled, “having wellbore integrity is essential,” she said.

Jewell also drew on her engineering experience at Mobil Oil Co., now part of Exxon Mobil Corp., to answer Rep. Alan Lowenthal, a California Democrat, who complained that the Interior proposal relies on the industry’s FracFocus website for disclosure of fracing chemicals.

FracFocus “is imperfect, but it’s being updated,” she said. If it’s not providing adequate disclosure, “we will look for other ways to do it.”