The EPA has downgraded Colorado’s North Front Range ozone problem to “severe” from “serious,” a long-expected move that requires state and local officials to take stronger runs at cutting the health-damaging pollution.

“The proposed reclassifications would require the State of Colorado to apply more stringent air quality measures to sources across the area,” an EPA release said, in announcing the proposed change after months of pressure from environmental advocates who said the deadlines to do so had already come and gone.

“Under the ‘severe’ reclassification, these requirements include the use of reformulated gasoline in summer months and a reduction of the threshold requiring control measures on emissions sources from 50 tons per year to 25 tons per year,” the EPA said.

In a previous interview that will be published on April 12, Colorado officials said the pending EPA downgrade will require hundreds of companies to get emission permits from a state system already critically backlogged. State health officials say their steep budget request is designed to clear the jam and improve the air.

It will mean state permits will be required for 473 more sources of pollution that contribute to ozone, as the threshold drops from 50 tons of covered pollutants a year to include all those emitting 25 tons or more, Air Pollution Control Director Michael Ogletree said. That new work will run headlong into a state health permitting system already assailed by courts and environmental groups as years behind, potentially endangering the health of more Coloradans living in highly polluted areas.

One set of permits at a key polluter, the Suncor Energy refinery in Commerce City, expired in 2012, and another in 2018, with a state court judge in January ordering Colorado Department of Public Health and Environment officials to finish renewing the permits “without delay.” When the state did issue a revised permit that it said put important new restrictions on Suncor, the regional EPA office sent the proposed permit back for tougher revisions in March.

“Our pollution control division is really at a transition point,” CDPHE Director Jill Hunsaker Ryan said in an interview. “It’s been under-resourced for two decades. We’re changing the way that we fund it. And I’m on a mission to really modernize and rightsize it to meet today’s air quality demands.”

EPA Regional Administrator KC Becker said, “Ground-level ozone remains one of the most challenging public health concerns we face, affecting large numbers of Coloradans and their families.” The reclassification “will make sure we are leveraging all available measures and resources as we move forward to reduce ozone pollution” with the state and other partners, she said.

This story is from The Colorado Sun, a journalist-owned news outlet based in Denver and covering the state. For more, and to support The Colorado Sun, visit The Colorado Sun is a partner in the Colorado News Conservancy, owner of Colorado Community Media.