DENVER— The Center for Biological Diversity filed suit today challenging an Environmental Protection Agency decision upholding Colorado’s refusal to ensure oil and gas companies meet statewide air-pollution control requirements.

The Center’s suit targets an EPA order allowing the Jared Polis administration to let the oil and gas industry avoid complying with federally approved state rules requiring pollution controls to limit harmful volatile organic compound emissions, or VOCs. If successful the Center’s legal challenge could require the oil and gas industry to do more to control harmful VOC emissions across the state.

“The Polis administration and Trump’s EPA are unfortunately teaming up to give the oil and gas industry a free pass to pollute,” said Jeremy Nichols, a senior advocate at the Center. “This lawsuit is about standing up for our clean air, our health, and our environment.”

VOCs are a group of harmful chemical gases that can pose serious public health risks, as well as react with sunlight to form ground-level ozone, the key ingredient in smog. They include substances like gasoline and solvent vapors, as well as substances that evaporate into the air from oil and gas produced by Colorado’s fossil fuel industry.

In a May 2025 legal filing with the EPA, the Center challenged Colorado’s approval of an air-pollution permit for the Hunter Mesa oil and gas wastewater-treatment facility south of the town of Rifle.

The facility disposes of toxic oil and gas industry liquid waste by evaporation through two 210,000 gallon holding tanks and several ponds, releasing large amounts of VOCs. Every year the facility can process more than 100 million gallons of waste generated from fracking and oil and gas well production.

Colorado’s air-quality regulations prohibit the disposal of VOCs by evaporation unless there are air pollution controls. The rules effectively require that companies take steps to control VOC pollution.

The Colorado Air Pollution Control Division determined the ponds at the Hunter Mesa facility were subject to state VOC control requirements, but didn’t require controls for VOCs from the more than 400,000 gallons of open air holding tanks. Even though the holding tanks handled the same liquid waste and released VOCs into the air by evaporation, Colorado air regulators claimed no controls were required.

“This is Alice in Wonderland logic and just underscores how low the Polis administration is willing to go to defend the oil and gas industry’s demands to pollute the air we breathe in Colorado,” said Nichols.

The Center challenged Colorado’s claim that VOC controls were not required, arguing the permit failed to comply with the Clean Air Act. If VOCs from the tanks were controlled, emissions would be reduced by 95% or more.

In a November 2025 ruling on the Center’s petition, the EPA upheld Colorado’s claims, finding that VOCs released by evaporation from liquid waste in the holding tanks at the Hunter Mesa facility did not constitute disposal by evaporation.

Today’s lawsuit, filed with the U.S. Court of Appeals for the 10th Circuit in Denver, aims to overturn the EPA’s ruling.

The case could have broad implications for oil and gas production and processing in Colorado. VOC pollution from oil and gas production and processing facilities is the result of industry disposing of VOCs by evaporation. Although Colorado has required some controls of emissions from the oil and gas industry, many facilities still operate with no pollution controls, including idled and low-producing oil and gas wells.

More information about the Center for Biological Diversity’s fight against air pollution is available at Protecting Air Quality Under the Clean Air Act.