DENVER (AP) — The U.S. Environmental Protection Agency is proposing to downgrade Colorado’s biggest population center from a “serious” to a “severe” violator of federal ozone standards.

The move would force the state and industry to adopt tougher local rules to improve air quality.

The EPA’s proposed reclassifications are based on a scientific evaluation of certified, publicly-available air quality monitoring data for the years 2018 – 2020 indicating the Denver Metro North Front Range has failed to meet the 2008 and 2015 ozone standards within the timeframes required by the Clean Air Act

Tuesday’s EPA recommendation is slated to be published in the Federal Record on Wednesday.

Gov. Jared Polis and fellow Democrats who control the Legislature are pursuing legislation costing hundreds of millions of dollars to reduce pollution sources.