The Four Corners Power Plant and San Juan Generating Station have been in operation for more than three decades. Located just south of the New Mexico border, between Shiprock and Farmington, both escaped regulation under the Clean Air Act. They were grandfathered in under the assumption that they were about to shut down. But they did not.

“What we have down there are two very old, very polluting coal-fired plants,” said Josh Joswick, of the San Juan Citizens Alliance. “Right now they are emitting everything from mercury to greenhouse gasses, nitrogen oxide and CO2. This pollution is not confined to New Mexico. We’re in the same airshed here.”

How dangerous are these coal plants? In a study by both the EPA Science Advisory Board and the National Academy of Sciences, estimated health impacts and costs are as follows:

San Juan Generating Station: Deaths: 33 ($240 million); heart attacks: 50 ($5.4 million); asthma attacks: 600 ($31,000); hospital admissions: 23 ($540,000); chronic bronchitis: 21 ($9.5 million); asthma ER visits: 31 ($12,000); total dollars $255 million per year.

Four Corners Power Plant: Deaths: 44 ($320 million); heart attacks: 66 ($7.2 million); asthma attacks: 800 ($42,000); hospital admissions: 31 ($720,000); chronic bronchitis: 28 ($13 million); asthma ER visits: 42 ($15,000); total dollars $341 million per year.

The EPA is proposing to retrofit both coal plants with “Best Available Retrofit Technology” (BART), which includes scrubbers and a process called selective catalytic reduction to clean the air. The EPA is accepting comments on the proposed rule through May 2 by email at: r9air_fcppbart@epa.gov. For more information, call 415-972-3958.

- Leslie Swanson