This is an archived article that was published on sltrib.com in 2017, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Take a step back from the complex reality of Utah's air pollution problems and one fact is inescapable. Without consistent, strong action from the U.S. Environmental Protection Agency in recent decades, the smog we suffer through during winter time inversions would be much worse than it is now.

That is why Utahns and our congressional delegation must resist efforts from the administration of President Donald Trump to slash the powers and budget of the EPA in the months to come.

Data from state officials shows a downward trend in total emissions in northern Utah valleys over the past 15 years. That's impressive and positive, especially considering the corresponding increase in population over the same time frame. To put it simply, even though so many people are moving here and our families are growing, we're managing to create less pollution.

Now, even as we acknowledge those improvements, it's important to recognize that we still have plenty of bad air days. We are not yet in attainment with federal air quality standards, designed to protect the health of our families and children. Just ask emergency room doctors, who see a sharp increase in patients when PM2.5 levels soar. Clearly, we have much work left, especially because our population will keep increasing.

The success of the past shows that future improvements are possible. So how is it that we have managed to reduce emissions? Drill down into the state's data and the answer is clear. We have benefited from EPA actions.

For example, there's the agency's ultra-low sulfur diesel program. Before the EPA begin regulating sulfur in diesel, it contained as much as 5,000 parts per million. Beginning in 2006, the EPA lowered it all the way to 15 ppm. Those standards reduced emissions from diesels by more than 90 percent.

And then there's the agency's programs for regular gasoline cars. Many Utahns have heard of Tier 3, which promises to reduce air pollution over the next two decades, but few are aware of the powerful benefits we're already receiving from the EPA's Tier 2 program. It reduced the sulfur in gas by up to 90 percent and required new emission control technologies in cars and trucks. Tier 2, in effect since 2004, lowered emissions by 77 to 95 percent.

That's a whole bunch of math, but here's the truth: Pollution from new Utah cars and trucks was much less than the vehicles they replaced. And even though we've added a bunch of cars recently, EPA action significantly reduced total emissions from that sector.

How did that happen? It happened because the EPA had the staff and the budget to study new technologies, to evaluate whether they were feasible, and to determine if they would make a difference in air pollution and for community health nationwide.

It's what the agency does. And it's what is at risk if the new president and the new EPA Chief Scott Pruitt get their way.

A crippled EPA won't have the staff or the budget to study technologies that could sharply reduce emissions from our furnaces and boilers, for example. It wouldn't be able to scrutinize emissions from freight engines or figure out whether new technologies can further reduce pollution from cars and trucks.

Utah's representatives in Congress often put forth rhetoric about "EPA overreach" and the need for "greater local control." Those words might help them get elected, but if they don't stand up for the agency's staff and budget in the months to come, it's the health of Utah's families and our children who will pay the price.

Matt Pacenza is the executive director of the local environmental nonprofit HEAL Utah.