The Interior Department will release a new proposal to regulate “fracking” on federal lands as soon as Thursday, a top industry official told The Hill.

“I expect they will be out tomorrow or Friday,” American Petroleum Institute CEO Jack Gerard said Wednesday.

{mosads}The proposal would regulate the oil-and-gas development method known as fracking, in which water, chemicals and sand are injected at high pressure into rock formations to open up seams that enable trapped oil and natural gas to flow.

The rules are expected to include the required disclosure of chemicals used in the hydraulic fracturing process, along with regulations on well integrity and wastewater management.

Fracking and advances in horizontal drilling technology are enabling a natural gas and oil production boom in many states, but have raised concerns about air pollution and water contamination as well. The rules are likely to set off a debate among energy companies and environmental groups. 

Industry groups and a number of individual companies that argue state-based rules are sufficient and that federal regulations could create burdens have recently lobbied White House officials about the Interior regulations.

Bloomberg, which obtained a recent draft of the rules, reported that they have been modified to allow companies to wait until after the fracking process has been completed to disclose the chemicals used.

Gerard, who addressed the rules in broad terms in the short interview, said he’s pleased with some of the changes to the upcoming proposal.

“We will have to look at all the details, of course; however, there have clearly been some constructive changes. We hope there will be many changes,” he said when asked if the group’s concerns have been addressed.

But he said states should have the primary role in regulating fracking.

“We are working with the [Interior] Department, we are working with the administration to find that proper role for state regulation, which we believe clearly should be the lead role in these areas,” he said.

Gerard spoke after a half-day conference in Columbus, Ohio, about shale oil and natural-gas development hosted by The Hill.

The Interior Department would not comment on the timing of the proposal’s release.

Andrew Restuccia contributed to this story.