The Oklahoma Department of Environmental Quality is drafting rules that would curb mercury emissions from coal-fired power plants.

A draft version released earlier this year adopts by reference a federal regulatory system seen by many as being far too lenient. The proposed rules also have been criticized for being the product of input provided primarily by utility companies that operate coal-fired plants, like Oklahoma Gas & Electric’s Muskogee facility.

ODEQ’s efforts to draft new mercury emissions rules were mandated in 2005 by the U.S. Environmental Protection Agency, which for the first time ever, attempted to regulate such emissions. Skylar McElhaney, ODEQ spokeswoman, said the Oklahoma Air Quality Council has been conducting public meetings every three months since April 2006 in an effort to draft rules for the state.

Mercury is a neurotoxin known to be especially dangerous to children and women of childbearing age. The effects of mercury exposure are similar to the effects of lead toxicity in children and include delayed development and cognitive deficits, language difficulties and problems with motor function, attention and memory.

According to the EPA, power plants are responsible for 41 percent of all mercury emitted by all known sources in the nation. Mercury levels in Oklahoma’s lakes and streams prompted ODEQ to issue an advisory in 2005, cautioning children younger than 15 years and women of childbearing age to limit consumption of locally caught fish to one meal a week.

The EPA announced in December 2000 that mercury emissions from coal-fired power plants threaten public health and the environment. The federal environmental agency found it “appropriate and necessary” to regulate utility hazardous air emissions using the maximum achievable control technology standards provided for in the Clean Air Act.

David Branecky, manager of air quality for OG&E and a member of the Air Quality Council, said it is unknown exactly how much mercury is being emitted from its Muskogee plant, but OG&E is installing equipment that will allow the company to begin monitoring mercury emissions. The cost of the monitoring equipment is estimated to be about $7.9 million.

The EPA rules adopted in 2005 overturned the agency’s December 2000 findings and applies instead a standard that is more lenient. The new standard purportedly gives the EPA flexibility to consider more cost-effective ways to control mercury emissions.

The EPA estimates the federal rules would reduce mercury emissions 70 percent by 2018. The attorneys general of several states have sued the EPA in favor of rules that would force coal-fired power plants to use standards required by the Clean Air Act which would achieve a reduction of mercury emissions by up to 90 percent.

“Under the Clean Air Act, power plants would have been required to use the best available technology to reduce mercury emissions,” stated an article in the Journal of American Medical Association. “In a reversal of this approach, on March 29, 2005, the EPA finalized a mercury rule that exempts the power plants from these requirements and instead would institute a program favored by the industry.”

The article cited an EPA report to Congress in 2000, which indicates the best available technology standard, if implemented, would have reduced mercury emissions from coal-fired plants by 90 percent — from about 50 tons to 5 tons a year — by 2008.

The EPA’s Clean Air Mercury Rule, which is being challenged in court, adopts a standard that falls short of what the Clean Air Act requires. The present rule would require a 70-percent reduction in mercury emissions by 2018 and includes a cap-and-trade system.

Some fear the cap-and-trade provisions under the federal rules would allow power plants to exceed emissions standards by purchasing credits from cleaner plants — most of which would be located outside the state. That system, some fear, could lead to mercury “hot spots.”

“Those opposing the federal rule believe that trading of emission credits would not be protective enough of the public health primarily because of the possibility of hot spots from local emissions,” McElhaney said. “Those who support the federal rule state that the hot spot issue has not been substantiated, and that additional, more stringent controls would be too costly.”