SPENCER, N.C. – The Bush administration is giving coal-fired power plants up to 20 years to remove 70 percent of the toxic mercury in smokestack emissions, citing as one factor that a key technology remains unproven.

But on North Carolina’s Yadkin River – at a type of plant where mercury removal was thought to be near impossible – a test shows that technology is already close to getting the job done.

“By 2010, we could outfit easily every plant in the country,” said Sid Nelson Jr., president of the Ohio company that supplied the plant with a mercury-capturing “sorbent.”

Officials at the U.S. Environmental Protection Agency say that such claims are overly optimistic and that more testing is needed. Environmentalists accuse the agency of favoring industry at the expense of public health, filing lawsuits almost immediately after the EPA rule was published last month.

But with four states requiring much faster action on mercury than the EPA – New Jersey’s rule, for example, takes full effect in 2007 – electric companies already are scrambling to find answers.

The reason for concern is that mercury, which occurs naturally in coal, can be deposited in waterways, where it can be converted into a highly toxic form of mercury that accumulates in fish. Too much of the wrong kinds of fish can harm the brains of developing fetuses and children. Some scientists believe excess mercury can cause heart problems in adults.

U.S. coal-burning plants contribute just 1 percent of the world’s mercury emissions and are thought to have little impact on commonly eaten saltwater fish such as tuna.

But a fair amount of the mercury from U.S. plants settles in the lakes and streams of downwind states such as New Jersey and Pennsylvania – which, along with Ohio and Indiana, are home to some of the nation’s biggest coal-burners.

Pennsylvania officials recommend eating no more than one eight-ounce meal a week of fish caught in state waters. For some lakes, the recommendation is just one meal a month.

The mercury-removal method used in a five-week trial at the Buck Steam Station, owned by a division of Duke Energy, is surprisingly simple.

The absorbent material, made by Sorbent Technologies Corp. of Twinsburg, Ohio, is a powdered substance called activated carbon – similar to what is used in home water filters. It is made from coal, not much different from the stuff power plants burn to make electricity.

The carbon is treated with the chemical bromine and then blown into the stream of exhaust gases. The carbon absorbs up to 75 percent of the gaseous mercury, and the resulting particles are then filtered out by the plant’s existing air-cleaning equipment.

All it took was a hopper full of carbon, a blower and a long black hose.

“This is as complicated as it gets right here,” said Duke engineer Stephen C. Potter. “It’s like a sponge. It soaks that mercury up.”

The project, funded mostly by the U.S. Department of Energy, cost less than $2 million.

Some kinks still need to be worked out. Some days, the carbon absorbs less than half the mercury. And sometimes the analyzer that measures mercury levels produces faulty data.

One day last month, for example, the device erroneously reported that mercury levels in the treated gas were higher than in the untreated gas.

(EDITORS: BEGIN OPTIONAL TRIM)

“You have to be able to prove you are in compliance,” said Duke program manager Don Weaver.

Yet company officials are optimistic, partly because they did much better than expected at Buck. The configuration of the facility – named for company founder James “Buck” Duke, after whom Duke University also is named – was thought to make mercury removal especially difficult.

As they travel through enormous ductwork toward the plant’s air-cleaning “precipitator,” the exhaust gases are quite hot, measuring about 630 degrees Fahrenheit. Carbon alone would not capture the mercury at such a high temperature, Nelson said.

The trick is treating the carbon with a chemical from the halogen family, such as chlorine or bromine. Brominated carbon forms a chemical bond with mercury even at high temperatures, he said.

Entrepreneurs learned that lesson by studying trash incinerators, which have been using activated carbon for years to reduce mercury emissions. The carbon used by incinerators is not treated, but chlorine enters the mix because incinerators burn a lot of plastics, which can contain the chemical.

(END OPTIONAL TRIM)

Nelson said if he can remove the mercury at Buck, he can do it anywhere. In previous trials at power plants with easier configurations, the activated-carbon technology removed up to 94 percent of the mercury.

In a regulated market such as North Carolina’s, the cost to consumers is estimated at $1 or $2 on a typical monthly electric bill. In a competitive, deregulated market such as Pennsylvania, the power company likely would have to absorb the expense.

Another promising technique is the installation of scrubbers, which are primarily designed to remove sulfur dioxide but also capture mercury if properly adjusted. Many plants must install these anyway.

Whichever technology is used, there is no sense in waiting to act, said John Stanton, a former EPA lawyer who is now vice president of the National Environmental Trust, a Washington-based nonprofit advocacy group.

“We have the technology,” he said. “The threat is real, and we should be acting today.”

The EPA rule reduces mercury emissions from power plants in two phases: a 38-ton cap goes into effect in 2010, down from the current 48 tons, followed by a 15-ton cap in 2018.

(EDITORS: BEGIN OPTIONAL TRIM)

But the agency estimates that full compliance won’t occur until at least 2025. Plants that make partial reductions before the deadline get extra time to meet their final target.

In its rule, the agency predicted the activated-carbon technology would not be “commercially available on a wide scale” until after 2010, and not on a national scale until 2018.

Jeff Holmstead, head of the EPA’s air-pollution control program, said the agency had no specific definition for the term “commercially available.” But he said several years of full-time operation on multiple plants would be needed. Claims that the technology is ready are overstated, he said.

“Those companies obviously have a product they want to sell,” Holmstead said.

(END OPTIONAL TRIM)

The EPA picked the mercury targets after weighing the costs of control technologies against the dollar value of the health benefits – an estimated $50 million a year. But they did not count the impacts that some scientists believe mercury has on the heart.

A study by the Harvard Center for Risk Analysis, funded partly by the EPA, pegged the potential impact of mercury control at 800 fewer fatal heart attacks a year, for an annual benefit of $4.8 billion. That’s 96 times the health benefits estimated by the EPA.

Critics say if the EPA had included the heart benefits in its analysis, it would have been forced to require faster cleanup. Holmstead countered that the evidence of a connection between mercury and heart attacks was “speculative.”