The Environmental Protection Agency has given Maine part of what it needs and deserves to meet Clean Air Act requirements. State officials have worked for more than two years just to get this far, but they need to keep pushing Washington to force upwind neighbors to improve their air quality.

The EPA last week told 22 states in the eastern half of the country to reduce the amount of smog-causing pollution from their power plants. Though Maine was not ordered to cut pollution, the action was important here. The decision should improve the air quality in Maine because a significant portion of Maine’s air pollution originates out of state, with its neighbors. That’s why Gov. Angus King and Department of Environmental Protection Commissioner Ned Sullivan properly took the lead on this issue and pressed the EPA for these changes.

The Midwest, which has numerous coal-fired power plants, will be most affected by the change. New England states, excluding Maine and New Hampshire, will reduce their production of nitrogen oxide (NOx) as well, but by a lesser amount. One indication that the EPA plan is forceful enough to actually improve air quality in downwind states is that American Electric Power, an energy company with nearly 3 million customers in the Midwest, immediately called for the EPA to forget the entire issue. It argues that the eight states — New England plus New York and Pennsylvania — that filed petitions with the EPA on the issue have their own pollution problems to solve.

Maine, in fact, would be better off if its New England neighbors had been required to make more serious reductions in their NOx emissions. While the Midwest contributes the most to smog in the region, Maine suffers more from pollution coming from Massachusetts than it does from Ohio. Also, the EPA reductions, while helpful, are too low for Maine to come into compliance with the current clean-air standards. Maine could help its case for other states to further restrict NOx emission by volunteering to include reductions here.

The EPA took an important step last week simply by recognizing that some states have been allowed to get away with unsafe pollution levels. Its initial NOx reductions were an encouraging start to what will be a long process of fairly bringing states into compliance with clean-air levels. Maine officials have done a commendable job so far on this issue, but should not let the recent EPA announcement be the end of their efforts.