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Could cuts in emissions come faster?

(Page 2 of 2)

Under it, power plants are expected to cut mercury emissions from 48 tons currently to 38 tons by 2010 - and cut to 15 tons by 2018, a 70 percent reduction, using mercury-specific technologies.

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Much of that first-phase reduction is expected to occur through "cobenefits" - cuts that occur by doing nothing more than meeting another new set of clean air requirements announced last week for reducing NOX and SOX. Those reductions are called the Clean Air Interstate Rule (CAIR).

Relatively few power plants today have both NOX and SOX removal gear like Mount Storm's. But under the new rule there should be many more Mount Storm-like conversions, experts say.

A key feature of both sets of new EPA rules is the use of market-based cap-and-trade systems. Under these, pollution allowances for mercury, SOX, and NOX may be purchased or traded by utilities. Such NOX and SOX removal systems may be efficient enough that they one day generate mercury credits sold on the open market - or compensate for other more polluting plants.

At Mount Storm, for instance, researchers for two pollution control companies ran three weeks of full-scale tests on how well NOX and SOX equipment removed mercury. In a research paper delivered this month, they revealed the two systems working together cut 98 percent of mercury emissions - a clear success.

"It was a nice result," says Tom Hastings of Cormetech, one of the pollution-control companies. "This plant is a good example. But I've also seen numbers in the 80- to 90-percent-plus range for a number of others."

And that's the sort of thing that bugs Mr. O'Donnell, the environmentalist, who says that companies have the capability to do more with the technology presently available - if the EPA would just make them do it.

Right now, for instance, the Mount Storm plant runs its SOX scrubber year round - but runs its NOX removal gear only five months a year, during the summer when it's a problem. But without the NOX system running, SOX alone removes about 70 percent of the mercury.

Whenever it decides that the cost of emitting the mercury under the new mercury rule exceeds the cost of running its NOX equipment year round, the company can throw a switch and remove more than 95 percent of its mercury.

When will that day come? When purchasing mercury-pollution allowances becomes more expensive than running NOX equipment year round, experts suggest. Or, at the latest, the new CAIR rule will require NOX equipment to begin operating year round at Mount Storm beginning in 2008, a company official says. Until then, much less mercury will be removed than is possible, if the tests conducted last summer are any indication.

Not to worry, say company officials.

"Mount Storm has become one of the cleaner plants in the country right now," says Dan Genest, a spokesman for Dominion Resources, headquartered in Richmond, Va., which operates Mount Storm and other power plants in several states from Illinois to Massachusetts. "Under the CAIR rule, we may not have to do as much [mercury reduction] at one of our other plants in Virginia, thanks to the cuts in mercury at Mount Storm. By doing that we would still end up complying with the mercury rules anyway."