A tale of two power plants


For many years, haze has tarnished the views at national parks, including Colorado’s Mesa Verde and the Grand Canyon. On bad days poor air quality  in Mesa Verde can cut visibility to just 20 miles. That's a stark contrast to the clarity of the early 1900s, when visibility was up to 162 miles on a crisp, clear day.

The Clean Air Act has provisions for safeguarding national parks and wilderness areas from being beset by haze and requires states to clean up emissions that lead to haze production. But enforcement has been lax. Back in 2009, the Environmental Protection Agency found that 37 states had submitted incomplete proposals, or no proposals at all, for how they planned to reduce haze-inducing pollutants.

The agency has since been clamping down on power plants and making rules for operators to cut emissions of things that cause haze, a mishmash that includes nitrogen oxide, a gas released during combustion, as well as particulate matter and soot from wildfires.

Two coal burning power plants, both hefty emitters of nitrogen oxide, are slated to drastically curb their emissions by 2018 and 2016 respectively. The Four Corners Power Plant (the largest source of nitrogen oxide emissions in the country) and the San Juan Generating Station both sit just over 30 miles from Mesa Verde. Last week, the EPA issued its final rule for the Four Corners plant, which is based on the Navajo Nation near Farmington, New Mexico, and is operated by the Arizona Public Service Company.

To comply with the EPA’s mandate, the utility company plans to shut down three of the plant’s oldest and least efficient units. On its remaining two units, it will also install what is known as selective catalytic reduction (SCR) technology to reduce nitrogen oxide emissions by 87 percent. This technology takes the combustion gas that would go out the plant's smokestack and passes it through a series of beds containing ammonia or urea and a catalyst, which breaks nitrogen oxide down into water vapor and nitrogen. Retiring the plant’s three older units and upgrading the remaining two will cut the plant’s contribution to shoddy visibility at 16 national parks and wilderness areas by about 72 percent.

Illustration of selective catalytic reduction technology, courtesy EPA.

Before it can clean up the two units, the Arizona Public Service Company needs to buy a major share in them from Southern California Edison, which currently has a controlling stake in the units, explains Damon Gross, spokesperson for APS. The company plans to complete the purchase by the end of the year, and then begin decommissioning the three old units. Upgrades to the plant will likely result in a rate increase of between 2 and 3 percent for customers, he says.

Just off the reservation, in New Mexico, the EPA’s efforts to cut emissions from the nearby San Juan Generating Station, which supplies electricity to more than 2 million customers in the Southwest, have not gone down quite as smoothly. Last June, New Mexico offered the EPA its plan for cutting emissions at the San Juan plant, which is operated by the Public Service Company of New Mexico. This proposed making use of selective noncatalytic reduction technology, which cleans up pollution by injecting ammonia or urea straight into high temperature parts of the boiler, a less efficient option than the selective catalytic alternative. The EPA rejected this plan. Under the Clean Air Act, polluters are required to install what is known as Best Available Retrofit Technology, a requirement that means EPA can judge pollution reform plans lacking if they do not meet certain technological specifications.

Since the utility company only has until 2016, it is already moving ahead with planning to follow the EPA’s recommendations of using selective catalytic technology. At the same time, though, it and the state have appealed the EPA’s ruling in federal court, and New Mexico is busy looking at the possibility of coming up with an alternative emissions reduction plan. Last month, EPA Administrator Lisa Jackson gave the plant’s operators some breathing room by giving the state an extra 90 days to come up with a plan, after New Mexico Gov. Susana Martinez made a special request. The New Mexico Environment Department now has until October 15 to figure out a new pollution reduction plan for the plant, and is holding a series of public meetings to get comments on an alternative to the state and federal plans.

“The viability of any alternative cleanup plan for the San Juan Generating Station will require buy-in from environmental, public health and other stakeholders,” Jeremy Nichols, of environmental group WildEarth Guardians, told Bloomberg Businessweek.

Based on an estimated cost of $750 million (the EPA estimate is $345 million), the price tag for fitting the plant could translate to an increase of up to $82 dollars per year for customers, says Valerie Smith, spokesperson for Public Service Company of New Mexico.

While these pollution reduction measures will help clear the air in national parks, they also carry health and environmental benefits. As HCN editor Cally Carswell explained in her 2011 article on the topic, “nitrogen oxide is a primary ingredient in ozone, which can make breathing difficult and aggravate respiratory ailments.” And nitrogen from power plants, agriculture, and combustion in the Front Range has already had a detrimental affect on lakes, streams, and soils in Colorado’s Rocky Mountain National Park.

Ultimately, the regulations don’t simply lead to a clearer view. They lead to cleaner air too.

Brendon Bosworth is a High Country News intern.

Image: San Juan Generating Station and San Juan Mine. Courtesy San Juan Citizen's Alliance/EcoFlight via Flickr.

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