The Environmental Protection Agency has admitted that its newly proposed limits on mercury from power plants are based in part on mathematical errors, the New York Times reports.
In a letter to industry lawyers yesterday, EPA assistant administrator for air and radiation Gina McCarthy said the agency made a mistake in its calculation of what levels of mercury the maximum achievable control technology (MACT) can achieve.
But she dismissed claims by the Utility Air Regulatory Group, a coalition of power companies, that the EPA had underestimated mercury emissions of the cleanest power plants by a factor of 1,000.
McCarthy said that fixing the error would allow U.S. coal-powered plants to release an extra 1,000 pounds of mercury each year. This is 1.7 percent of the 29 tons of mercury that these plants currently release. She said that after the correction, power plants will still need to trap 90 percent of the mercury found in the coal they use.
Utility company attorneys are arguing that because of the error, the public comment period for the rule should be extended.
House energy and commerce chairman Fred Upton (R-Mich.) and Sen. James Inhofe (R-Okla.), the minority leader on the Senate environment and public works committee, have also asked the EPA to give utilities an extension.
But an EPA spokesman told the Times that the agency isn’t planning to change the schedule for the comment period, and he disputed claims that the final rules will be too expensive for utilities to adhere to.
The EPA announced the national standards on power plants’ emissions of mercury, arsenic and several other toxic air pollutants in March.
Picture credit: Norbert Löv