Air quality in the United States has made “significant progress” since 1970, even as the nation’s economy, population, miles driven, and energy use have increased, according to a new report from the Environmental Protection Agency.

Dubbed “The Greatest Story Seldom Told” by the Association of Air Pollution Control Agencies, “the combined emissions of six key pollutants dropped by 73 percent, while the U.S. economy grew more than three times,” the EPA wrote.

“Today Americans breathe cleaner air and face lower risks of adverse health effects,” the EPA wrote.

“Despite this success, there is more work to be done,” said EPA Administrator Scott Pruitt. “Nearly 40 percent of Americans are still living in areas classified as ‘non-attainment’ for failing to achieve national standards.  EPA will continue to work with states, tribes, and local air agencies to help more areas of the country come into compliance.”

The EPA’s 2017 report features an interactive look at a variety of emissions, concluding that “state and local air agencies have been responsible for tremendous progress in virtually every measure of air quality.”

“Colorado has made significant progress in reducing ozone emissions, both through the Clean Air Clean Jobs Act and the 2014 methane regulations,” Gov. John Hickenlooper told Western Wire in June. “Regardless of what the federal government does, we will reduce ozone pollution not only for cleaner air, but for improved health of the citizens of Colorado.”

Hickenlooper, the state’s top Democratic official, has called for the suspension of the Obama administration’s 2015 ozone rule, acknowledging the state’s progress towards the EPA’s 2008 standard while admitting that western states have a tougher path to meeting increasing federal air regulations.

Any “delay of the 2015 standard will not deter our efforts to move toward compliance with the 2008 standard,” Hickenlooper wrote.

“I mean, just with the background [ozone emissions], if you’re not going to be able to conform to a standard like this, you are leaving the risk or the possibility that there will be penalties of one sort or another that come from your lack of compliance,” Hickenlooper said.

Will Allison, director of the Colorado Department of Public Health and Environment’s Air Pollution Control Division, told the Denver Business Journal in early 2016 that, in the case of ozone, “30 to 50 percent of the ozone that we’re monitoring is background and beyond our control.”

CDPHE did not respond to Western Wire by press time.

“We could shut down all of our Valley businesses and we will not get enough reductions to meet the standard,” Seyed Sadredin, executive director of the San Joaquin Valley Air Pollution Control District, said during a recent U.S. House hearing. Sadredin’s district regulates air quality across eight counties in California’s Central Valley.

Western states face a broad number of challenges in combating ozone-forming emissions, including ozone and other sources that move into the states from Mexico and China, according to the Western States Air Resources Council.

Federal regulations moving forward without state input would be “just setting us up to fail,” said State Sen. Cheri Jahn (D-Wheat Ridge) at the time.

U.S. Sen. Michael Bennet (D-Colo.) has also expressed doubts about Colorado meeting new background ozone standard at the 70 ppb level, given state factors such as topography and geography that heavily influence background ozone levels.


The EPA’s decision to tighten the standard in 2015 drew bipartisan opposition, including the U.S. Conference of Mayors and the National Association of Counties who warned the EPA that a lower standard would force non-attainment and “negatively affect job creation and critical economic development projects.”

Several states across the West have filed lawsuits challenging the ozone rule, including Arizona, New Mexico, Oklahoma, Utah, North Dakota, and Texas.

Meanwhile, fifteen states have sued the EPA over the planned one-year delay of the 2015 ozone standard, with Democratic attorneys general for California, Connecticut, Delaware, Illinois, Iowa, Maine, Massachusetts, Minnesota, New Mexico, Oregon, Pennsylvania, Rhode Island, Vermont, Washington and the District of Columbia joining New York’s Eric Schneiderman.

The United States’ GDP has grown 253 percent since 1970, according to the EPA, with the number of vehicle miles traveled nearly tripling at 190 percent. Meanwhile, population and energy consumption have moved up 58 and 44 percent, respectively over the past 46 years.