A petition by environmental organizations 350 Colorado and the Center for Biological Diversity over state ozone control plans approved by the Environmental Protection Agency in 2023 was rejected by the U.S. Court of Appeals for the 10th Circuit in Denver on Tuesday.

The environmental organizations complained that the decision by the EPA to approve Colorado’s state implementation plan concerning reasonable further progress, motor vehicle emissions and anti-backsliding components of the plan in 2022 violated the Clean Air Act.

“The EPA’s approval of this pollution-reduction plan, which we already know has failed, could have been straight out of George Orwell’s dystopian novel, “1984,” said Robert Ukeiley, an environmental health attorney at the Center for Biological Diversity, in a July 2023 release announcing the petition. “This government embrace of a plan that has already failed means the fracked gas and oil industry gets to keep spewing out pollution that causes asthma attacks and even death.”

The Court of Appeals disagreed with the organization’s interpretation of the Clean Air Act.

“Despite the state’s failure to achieve attainment and the resulting reclassification, the EPA approved certain components of Colorado’s “serious” SIP submissions in May 2023,” said the court ruling. “As relevant here, the EPA approved the reasonable-further-progress demonstration, determining that Colorado showed emissions would fall by at least 3% per year from 2018 to 2020.”

The Colorado Department of Public Health and Environment applauded the court ruling.

“We’re proud the court upheld the U.S. Environmental Protection Agency’s approval of our State Implementation Plan,” said the agency in a statement. “This plan is an important part of our ongoing work to address ozone pollution in Colorado.”

“By satisfying the basic benchmarks and achieving 3% average annual emissions reductions, the state and the EPA carried forth a plan that was designed to — and in fact did reduce emissions and made reasonable further progress under the Act,” said attorney Jack Luellen of the Buchalter Energy & Natural Resources Practice Group in Denver in a statement to The Denver Gazette.

The state could have determined attainment was not possible in the timeframe required and done nothing, said Luellen.

Ozone pollution in the Denver Metro/North Front Range Ozone Non-Attainment Area has resulted in ongoing attempts to control the precursors that form ozone for decades. While the state has been making progress toward meeting air quality standards set by the EPA, in 2019 the agency reclassified the area from “moderate” to the “severe” nonattainment category, which triggered revisions to the state implementation plan (SIP), which informs EPA how Colorado plans to meet the ozone standards by 2027.

The State Implementation Plan is a requirement of the Environmental Protection Agency for localities where ozone measurements exceed EPA limits.

The EPA’s nonattainment designation for Colorado includes nine counties from Douglas County in the south to Weld and Larimer counties in the north, as well as Boulder, Denver, Arapahoe, Jefferson, Adams, and Broomfield counties.

The region was declared in nonattainment in 1978, when ozone levels exceeded 120 parts per billion, the 1978 EPA national ambient air quality standard. Since then, the ozone level standards have been lowered to 75 parts per billion, making it more difficult for Colorado to comply with the standards.

A large part of the problem is the geography of the area and natural and outside sources of ozone and ozone-creating chemicals play the largest role in exceeding EPA standards.

According to the Colorado Air Pollution Control Division, in 2023 roughly 78% of ozone in the nonattainment area comes from background, natural, wildfire and other anthropogenic sources outside the area, including from states upwind and from as far away as China.

That means Colorado can control only about 22% of the ozone that is putting the state in violation of Clean Air Act standards, according to air pollution experts.

The state Regional Air Quality Council, the lead air quality planning agency for region acknowledges the problem of imported and natural ozone-creating chemicals.

“We essentially assume that we have control of about 25% to 30% of the ozone in our region,” said Mike Silverstein, RAQC’s Executive Director during an online press briefing last July. “And that’s what we’re responsible for developing strategies for to control.”

“The appeals court applied the right standard of review under the Clean Air Act,” said environmental attorney Paul Seby. “Of course, separate from the CBD’s claims is the fact that Colorado arbitrarily excludes consideration of the large amounts of out of state air pollution that travels to Colorado. The same statute gives Colorado authority to factor that circumstance in when developing air regulations from in-state sources. Unfortunately, Colorado chooses to ignore that authority and instead heavily penalizes in-state sources for emissions they don’t generate.”

The Center for Biological Diversity did not respond to requests for comment.