Colorado public health officials routinely allow oil and gas companies to begin drilling and fracking without obtaining federally required permits that limit the amount of pollution they can discharge into the air.

The state Department of Public Health and Environment allows companies to release emissions without permits under a decades-old exemption that gives a 90-day window, the Denver Post reported Sunday.

During that timeframe, companies are required to install pollution control devices to minimize emissions, but state inspectors do not check unless they receive specific complaints.

State officials said this approach lets companies determine how much a site will likely pollute, so regulators can take that into account when they issue air pollution permits later.

The state is allowing companies to pollute without permits at 193 sites, according to documents. Officials said air pollution permit applications are being processed at those sites.

U.S. Rep. Diana DeGette, a Democrat, has urged the state to close the exemption.

“If you have a loophole like this exception that has been identified, you need to close it,” DeGette said. “What should happen now is that the state should change its policy. They should first process the permit and then allow oil and gas exploration to occur.”

State health officials said they have started reviewing whether the exemption complies with the federal Clean Air Act.

“We have been in contact with Representative DeGette’s office to ensure that our regulations not only minimize emissions from the oil and gas sector but also fully comply with the dictates of federal law,” said Garry Kaufman, director of the state Air Pollution Control Division. “As a department, we are determined to be more assertive than ever in ensuring that we hold corporate polluters accountable and ensure every Coloradan has clean air to breathe.”

The Environmental Protection Agency had an “initial discussion” with health officials about the state’s permitting program, agency spokesman Andrew Mutter said.