FLAGSTAFF, Ariz. (AP) - Thursday marks the deadline for the U.S. Environmental Protection Agency to finalize an action to control emissions from three Arizona power plants.
The agency had proposed approving Arizona's air quality plan to reduce sulfur dioxide and soot at the Cholla, Coronado and Apache plants. But the EPA had indicated that the state's plan to lower nitrogen oxide emissions didn't go far enough.
The EPA proposed that they be equipped with selective catalytic reduction technology to further cut pollutants that cause regional haze and visibility issues at places like the Grand Canyon.
Environmentalists had praised the proposal.
The state and the plants' operators have said that the EPA's proposal would cost hundreds of millions of dollars with negligible improvement to air quality. Those costs would be passed on to ratepayers.
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