Workers test mercury emissions control equipment recently installed on the San Juan power plant in the four corners region. Photo courtesy of PNM.

Workers test mercury emissions control equipment recently installed on the San Juan power plant in the four corners region. Photo courtesy of PNM.

ALBUQUERQUE — New Mexico’s largest utility company, Public Service Company of New Mexico, has completed a major environmental upgrade of its San Juan coal-fired power plant, the company announced in a statement today.

The San Juan Generating Station is one of the two coal-fired power plants located in the four corners region of the state. The other one — called Four Corners Power Plant — is owned by Arizona Public Service company. Both plants in combination with the expanding oil and gas industry in the region have contributed to air quality problems in the region.

The Four Corners plant has not undertaken similar upgrades, Jim Norton of the New Mexico Environment Department told the Independent last week, and the oil and gas industry is expanding in the region, which also poses a problem.

“Ozone is a serious problem in that area, making it a whisker away from being designated as above allowable federal ozone standards,” Norton explained.  “And the many new oil and gas wells add to the problem.”

“There are quite significant emissions associated with oil and gas development, because it means a lot of engines are moving the natural gas around,” Norton explained.  “Similarly, these wells have tanks where oil and gas are stored, and as the tanks are vented, a lot of pollution is released into the air.”

Norton said one solution was put forward in a bill passed in the 2009 legislative session, that was signed by the governor.  HB 195 will allow the department to more strictly regulate emissions from the oil and gas industry to a standard higher than current federal standards.

The environmental upgrades on the San Juan power plant should help the ozone problem in the region, along with other emissions programs.

PNM undertook the three year, $330 million upgrade of the plant as the outcome of a 2005 agreement it struck with the state of New Mexico, the Sierra Club, and  the Grand Canyon Trust. The upgrade will reduce the plant’s emissions by about 14,000 tons annually.

“I commend PNM and the other owners of San Juan for completing this significant effort to reduce the plant’s impact on the environment,”  Gov. Bill Richardson said in the statement. “This investment in pollution controls, as required by an agreement PNM made with the state and environmental groups in 2005, means cleaner air for New Mexicans.”

And PNM president and CEO Pat Vincent-Collawn said the upgrades mark a new “chapter” for the plant.

“The completion of the upgrades and the payment of this assessment closes one chapter in the plant’s history and begins a new one,” Vincent-Collawn said. “The employees who have worked so diligently on the upgrade deserve to be commended for their work – and we all are proud that the plant will have a smaller impact on the environment going forward.”

The upgrade involved four units at the plant, and PNM said in the statement that data from the first three units already shows significant reductions of four primary emissions: an “80 percent drop in mercury emissions, 20 percent drop in sulfur dioxide emissions, 30 percent drop in nitrogen oxide emissions, and a significant reduction in particulate matter emissions.”

The statement continued with a description of the upgrades:

The upgrades included installation of state-of-the-art mercury control technology, state-of-the-art low-NOx burners and overfire air, particulate baghouse control technology, and systems to increase the scrubbing and removal of SO2.

As part of the agreement, PNM agreed to lower permit levels on emissions and to pay the state for excess emissions while the plant was being upgraded.  PNM and the other owners have been accruing the funds in escrow since the settlement was signed and have now paid the state $6.9 million for those emissions.  PNM’s portion of that total, based on its ownership of the plant, is 47 percent.

In a separate statement last month, Grand Canyon Trust welcomed the San Juan upgrade but struck a cautionary note about the prospects for air quality in the region overall:

While the upgrade will remove thousands of tons of pollution every year from the region’s air, the conservation groups warned that gains made by lowering pollution levels at San Juan could be overrun by new polluters; including the proposed Desert Rock power plant and regional expansion of oil and gas development. The groups also agreed that the aging Four Corners plant, another well-known pollution source, needs to upgrade its pollution controls.