A Canyonlands National Park ranger explains the air monitoring station in Island in the Sky to visitors. Utah regulators recently released an updated plan to reduce regional haze at the park and other prime airsheds around the state. [Photo by Neal Herbert / National Park Service]

Regional air quality could improve significantly by this time next month, when utility Rocky Mountain Power is set to close its aging Carbon coal-fired power plant near Helper.

State regulators are predicting that the looming closure of the 172-megawatt facility could go a long way in enhancing year-round visibility at places like Canyonlands National Park’s Island in the Sky district. They’re factoring the anticipated reductions into an updated plan to reduce regional haze at national parks and high-quality airsheds in eastern Utah, western Colorado and northern Arizona.

“We have a lot of confidence that we’re going to see results over the long term,” Utah Division of Air Quality environmental scientist Colleen Delaney said March 9.

Rocky Mountain Power spokesman Dave Eskelsen said his company believes the state’s proposal falls in line with the outcome that the U.S. Environmental Protection Agency (EPA) is seeking.

“You actually get better results with the state’s plan than you would with greater nitrogen oxide controls,” Eskelsen said.

But environmental groups and clean air advocates say the state’s plan doesn’t go far enough to reduce emissions that contribute to degraded visibility at national parks.

They argue that the Utah Air Quality Board should adopt stricter controls on emissions from Rocky Mountain Power’s much larger Hunter and Huntington coal-fired plants in Emery County, which are directly upwind of Moab.

Local resident Wayne Hoskisson, who serves with the Sierra Club’s Glen Canyon Group, said that regional air quality problems are complex, and can’t be solved with a single action.

“There are a whole lot of issues around air quality and regional haze here that are not going to be satisfied by closing one smaller plant,” he said.

On the other hand, Hoskisson believes the state can tackle those problems by ordering Rocky Mountain Power to upgrade its 1,300-megawatt Hunter Plant near Castle Dale and its 895-megawatt Huntington Plant near the town of the same name.

“We do think those two are the primary pieces for solving air quality problems at Canyonlands,” he said.

Grand County Council vice chair Chris Baird encourages the plants’ operator to follow the steps that coal-fired power plants in neighboring states have taken – or are taking – to cut their emissions.

“If we have the capacity to eliminate our emissions, then we ought to do it,” he said.

Delaney counters that both Emery County plants have already made extensive upgrades to their emission-control technologies.

“Back in 2008, pretty substantial improvements were made at all of the units we’re looking at,” she said.

In recent years, she said, those upgrades have led to “very substantial” reductions in emissions of sulfur dioxide and nitrogen oxides – including a 50 percent drop in nitrogen oxide emissions.

Delaney said that criticism of the state’s plan to reduce regional haze overlooks the accomplishments that Utah regulators have made over the last 15-plus years.

“A lot has been done, and it was done early,” she said. “You need to look at the bigger picture of what’s been achieved.”

However, Baird thinks that the state’s plan falls short in one emerging area of concern.

When nitrogen oxides react with volatile organic compounds on sunny days, they form another pollutant: ground-level ozone.

As it is, Baird said, ground-level ozone concentrations at Island in the Sky sometimes teeter on the edge of acceptable levels, as defined by a group of EPA advisers.

“We’re right on the threshold of the upper level of what’s considered healthy by the Clean Air Scientific Advisory Committee,” he said.

In the near future, the EPA is expected to reduce the current ground-level ozone standard from 75 parts per billion to 70 parts per billion. Baird noted that the agency could adopt an even lower standard, and he believes the state needs to be prepared for the changes.

Ground-level ozone not only impacts visibility; it also threatens the health of visitors who come to Canyonlands and Arches national parks to play outdoors, Baird said. According to the EPA, both ground-level ozone and nitrogen oxides are linked to a number of adverse effects on the human respiratory system, such as asthma.

“I don’t know if they take into consideration the fact that there are millions of tourists outside,” Baird said.

Eskelsen maintains that the improvements Baird and others are seeking would come at a high cost to the company and its customers.

“You’re talking about several hundred million dollars in investments,” Eskelsen said.

Even then, he said, there are no guarantees that the upgrades would achieve the same results that the state expects to see from the Carbon Plant closure.

“You wouldn’t get much of a benefit,” he said.

Delaney places those potential costs even higher, at an estimated $650 million.

“It’s a much cheaper reduction to be controlling – or, in this case, shutting down – the Carbon Plant, than it would be to install much more expensive technologies at the Hunter and Huntington plants,” she said.

On average, the Carbon Plant burns 657,000 tons of coal annually, compared to 4.5 million tons that the Hunter Plant burns through in an average year.

Despite that wide discrepancy, researchers found that the Carbon Plant released more than 8,000 tons of sulfur dioxide and 3,342 tons of nitrogen oxides per year, according to the Utah Division of Air Quality.

“Even though its electrical generating capacity is much less, its emissions are actually much higher,” Delaney said.

Eskelsen said the plant is showing signs of its age. It was first commissioned in 1954 – years before former President Richard Nixon signed the Clean Air Act into law, and decades before former President George H.W. Bush updated the landmark federal regulation.

Utah’s air quality division first came up with its own plan to control regional haze in 2008.

Four years later, the EPA approved a majority of that plan. However, it rejected portions that dealt with nitrogen oxide and particulate matter pollution from the Hunter and Huntington units, forcing the state to go back to the drawing board.

The air quality division ultimately simplified its proposed changes by invoking a provision that allows it to move forward with an alternative strategy to cut emissions – in this case, that strategy involves the closure of the Carbon Plant.

Delaney said the agency could have finalized the proposed changes on its own. But officials wanted to give the public a chance to review the plan beforehand, she said.

A 30-day written public comment period on the proposed changes is expected to begin on April 1. The state’s air quality board could vote on the updated plan at its meeting in June.

For more information about the state’s proposed revisions, go to airquality.utah.gov; scroll down to “Public Notices,” and click on “Regional Haze State Implementation Plan.

Critics say proposal doesn’t go far enough

“You actually get better results with the state’s plan than you would with greater nitrogen oxide controls.”

“If we have the capacity to eliminate our emissions, then we ought to do it.”