Environmental Protection Agency concluded today that emissions from a massive coal-fired power plant in Arizona cause up to 70% of the air pollution over the Grand Canyon and must be curbed.
In announcing its preliminary findings, the EPA said it expects a final decision by next February on how pollution from the Navajo Generating Station is to be curbed.
Operators of the Page, Ariz., plant about 12 miles from the northern rim of the canyon have argued that no additional pollution curbs should be required because much of the canyon pollution comes from sources in the Los Angeles area and Mexico.
But the EPA said the Park Service tests using a chemical tracer that was released through the power plant's 750-foot smokestacks demonstrated that on average about 40% of the pollution over the Grand Canyon originates with the plant and during some periods the percentage is as high as 70%.
Officials said a solution may require the plant to install expensive "scrubber" technology to reduce sulfur dioxide emissions, which range as high as 12 to 13 tons an hour during peak power periods.