Environment

New Draft Plan for Metro Denver Ozone Reduction Already Catching Heat

State agencies are trying to plan for a cleaner air future.
State agencies are trying to plan for a cleaner air future. CDPHE
Since the Environmental Protection Agency decided in April to downgrade the status of the northern Front Range from a serious violator of federal ozone standards to a severe violator, state entities have been reworking the two State Implementation Plans regarding ozone. The SIP draft was just released, and it's already catching heat.

The northern Front Range includes nine Colorado counties and stretches from Fort Collins to Castle Rock; the area was downgraded because it failed to bring ozone below the EPA’s 75 parts per billion National Ambient Air Quality Standard, which the agency established in 2008. It also established a new standard of 70 parts per billion in 2015, with which the area also does not comply.

Ozone is a secondary pollutant that forms when other pollutants — primarily volatile organic compounds and nitrogen oxide — mix with heat and sun. It can aggravate lung conditions such as asthma and chronic obstructive pulmonary diseases; it’s particularly dangerous for young children and adults over 65. Denver ranks seventh on the American Lung Association's list of most polluted cities for ozone in 2022.

The Regional Air Quality Council is the air-quality planning agency for the Front Range; on July 26, Executive Director Mike Silverstein and Air Quality Planner Wayne Chuang offered a briefing on the just-released SIP draft. Several items in the draft automatically kicked in because of national standards, they explained.

For starters, more sources of emissions are considered major sources and are subject to stricter Title V permits as specified by the Clean Air Act. The major source threshold had been 50 tons of ozone per year; now it will be 25 tons per year.

The state will also be required to provide reformulated gasoline, which causes fewer tailpipe emissions than traditional gasoline, at fuel pumps in the summer season starting in 2024.

The plan includes additional strategies to tackle oil and gas emissions of nitrous oxide and volatile organic compounds, regional haze, pollution in Weld County, greenhouse gas emissions and home electrification.

The RAQC projects compliance with the 2008 standard before 2027, which is when the area must achieve compliance, but does not expect to achieve compliance with the 2015 standard by 2024, which is the date for compliance with that standard. According to Silverstein, additional actions will be needed to reach that goal, but none of them will be in this iteration of the plan.

“All strategies are in place to improve air quality,” Silverstein said. “They're just not getting us to compliance by 2024, and so that tells us that we need to do more to get to reducing emissions even further.”

One of the challenges is that the modeling used to predict compliance is not as reliable in the short term because of recent severe meteorology events in summer months, including high temperatures and fires. “We know that our modeling isn't perfect, but modeling is never perfect, and it's used in a relative way,” Silverstein noted

Modeling also came up during a Colorado Public Interest Research Group forum on the RAQC draft plan, which was also held on July 26.

“People get frustrated when we say we're going to be in compliance and then we're not, and then we've lost a couple of years in the process for any meaningful regulation in this region to take effect,” said Gregg Thomas, division director for the Environmental Quality Division of the Denver Department of Public Health and Environment.

Some stakeholders are worried that could happen again if the plans don't add more control measures. Earlier this month, several local governments suggested nine control measures that could be added to the draft, including a greater commitment to clean cars, programs that increase transit ridership, indirect source rules, curtailing high-emission oil and gas industry actions during ozone season, flare minimization in the oil and gas industry, stronger non-road engine standards and low nitrous oxide appliance requirements.

The RAQC is responsible for transportation-related controls, while the Colorado Department of Public Health and Environment is responsible for weighing in on oil and gas. Environmental groups want the plan that the RAQC submits to the AQCC to be much stronger than the draft is now.

“It sets the whole tone for the process,” Alexandra Schluntz of EarthJustice said at the forum. “That first draft needs to be as strong as possible so that we can have a really robust public rulemaking process and get the public engaged, improve the SIP and, finally, get a strong final SIP approved by the Air Quality Control Commission.”

Thomas, who was once a member of the RAQC, said that he appreciates its work but also sympathizes with the frustration people have with downgrade after downgrade.

The RAQC will be taking comments on the draft at its August 5 board meeting; comments can also be sent via email by July 27. The RAQC expects to formally present the plan to the AQCC on September 13; an AQCC hearing on the final SIP is expected on December 13. It will then be submitted to the EPA for review.

“It does feel like this is a pivotal moment,” CoPIRG director Danny Katz concluded. “We can't really afford another few years of not being proactive. We’ve certainly seen some proactive measures coming out in the legislature. ... There are a bunch of things that are happening, but it does feel like we need more.”
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Catie Cheshire is a staff writer at Westword. After getting her undergraduate degree at Regis University, she went to Arizona State University for a master's degree. She missed everything about Denver -- from the less-intense sun to the food, the scenery and even the bus system. Now she's reunited with Denver and writing news for Westword.
Contact: Catie Cheshire