The Board of Environmental Protection early next month will decide whether to accept a proposal that would sharply curb the pollutant nitrogen oxide, a component of smog, coming from the smokestacks of FPL’s Wyman Station or allow an alternative that would let FPL purchase pollution credits. The board’s goal should be twofold: Ensure the program it chooses effectively reduces smog and keep the state’s rules roughly in line with those in the rest of the region.

That would lead the board to a proposal created by the Ozone Transport Region, made up of states in a swath of the Northeast from Maine to Washington, D.C. This plan already is appproved by the Environmental Protection Agency and would result in roughly a 75 percent reduction in NOx by 2003. Like the DEP plan, it would allow facilities to produce .15 tons of NOx for every 1 million Btus created.

The OTR proposal, based on a principal called cap and trade, allows power-generating facilities within a region to buy pollution allowances from other facilities to meet or help meet the .15 standard. The DEP supported the program when it was proposed and has never withdrawn its support. Maine, in fact, has a similar cap-and-trade program for reducing acid rain pollutants. The NOx program’s net effect for the region is to have the same overall pollution reduction if each facility met the .15 standard, but cap and trade allows for more flexibility and cost effectiveness among individual power plants.

In the case of the oil-fired Wyman Station, situated on Cousins Island in Yarmouth, the difference between the DEP plan and the one by OTR is $40 million and, practically, whether the 850-megawatt plant will continue beyond the beginning of the new rules. FPL figures it can meet the regional plan with upgrades and emissions trading for $10 million; it reports the DEP plan would cost $50 million.

The desire for more stringent standards at Wyman is understandable, particularly given the fact that cleaner-burning natural gas plants will be on line in the next few years. But Maine has good reason to accept the regional approach, and less smog in Southern Maine may be one of them.

Because all of the facilities that Wyman could trade emissions with are upwind, the Portland area, the part of the state with some of the dirtiest summertime air, would benefit from out-of-state reductions. Further, a state cap would ensure that any new sources of NOx would have to find offsets no matter what level of pollution they added, contributing to a more reliable pollution reduction than a facility-by-facility standard. Several states in the OTR already have adopted the cap-and-trade program, and more are expected to in the coming months. Maine has maintained its influence in arguing for tougher restrictions for far dirtier coal-fired plants in the Midwest by sticking with OTR standards and would benefit by continuing with them now.

Officials at DEP acknowledge the benefit of the cap-and-trade program even while proposing an alternative, so there is no reason for this to be a contentious issue. Instead, it is a matter of figuring out a way to reduce this pollutant cost effectively and for the entire region.