The day the lights went out from Peoria to Boston, August 14, 2003, was one of the hottest days of the summer in the Chesapeake Bay region. That day, as well as the several that followed, could have been code red days, but were not. In fact, the amount of ozone in the atmosphere was recorded in the moderate range on Aug. 15 and 16.

The reason? Hundreds of miles west of Baltimore, huge, coal-fired power plants had shut down. For two days, one of the Chesapeake region’s major sources of pollution was off-line and prevailing winds coming from the Midwest and South were uncharacteristically free of pollutants. This respite from ozone-laden air reinforced the notion that any strategy to clean up the Chesapeake Bay must address pollution created in other states.

Pollution in the Bay comes mainly from three sources: wastewater treatment plants, non-point sources (including fertilizer and manure washed off from farmland, runoff from paved surfaces in cities and suburbs, and tens of thousands of overfertilized lawns) and a less-publicized but important interstate source—the air. Air pollutants come not just from the seven jurisdictions that make up the Bay watershed (Maryland, Virginia, Pennsylvania, the District of Columbia, New York, Delaware and West Virginia), but also from industries in states south and west of the Bay, and from every vehicle that burns gasoline or diesel fuel—from 18-wheelers hauling goods up and down Interstate 95 to minivans delivering kids to soccer practice.

The pollution assault on the Bay is enormously complex, and each pollution source presents a challenge. None, however, tests our resolve to ensure a clean environment more than airborne pollutants, if only because this pollution source requires an equal commitment by each state as well as by the region as a whole—including states in the Ohio River Valley—to achieve clean air.

In reality, if we are to achieve the needed reductions in airborne pollutants and thus reduce deposition in the Bay and its watershed, we are going to have to deal with this issue on a multistate basis.

To effectively deal with the airborne transport of pollution to Eastern states, we must accept and enforce limitations on the amount of pollutants we permit to be added to the air; geography does not confer a license to pollute. If individual states are unwilling or unable to limit emissions at power plants within their borders, then collective action—that is, intervention by the EPA or by groups of states—is the most effective alternative.

There are times when legal action is unavoidable. Suits filed by the EPA against Midwestern power plants is one example. The challenge by Maryland and other states to the federal agency’s decision to change the New Source Review Program of the Clean Air Act is another example. Alternatives to legal action are preferable, though.

In 2001, the Bush administration unveiled its Clear Skies Initiative to address the regional transport of pollutants from coal-fired power plants. In the most recent legislative proposal, the Clear Skies Act of 2003, the administration envisions a 70 percent reduction by 2018 of three pollutants—nitrogen oxides, sulfur dioxide and mercury.

The primary concern of Northeastern states is that Clear Skies reductions will not be large enough or soon enough for many areas to reach attainment of their mandatory air quality goals in the 2010-2012 time frame. The recent proposal by the Ozone Transport Commission—a consortium of 12 Northeastern states and the District of Columbia—is a far more positive approach, and one that would have a greater impact on air quality in Maryland and other states in the region.

To address this challenge, Maryland has taken the lead in assembling a coalition of states, including the OTC states, to push Congress to enact a “Clear Skies Plus” package, one that goes beyond the provisions of the Clear Skies Initiative.

Maryland believes, and a number of other states agree, that many of the upwind coal-fired utilities east of the Mississippi must install technologies to achieve reductions of NOX and SO2 emissions by around 90 percent in the 2012 time-frame. Only with these regional reductions will downwind Eastern states have a chance of attaining necessary public health and air quality goals.

Maryland also believes the other pollutant of concern, mercury, can be addressed in the near-term by the very technologies used to reduce NOX and SO2, a “co-benefit” that can achieve 50-75 percent reductions in mercury emissions.

We can install additional mercury controls as needed in the future to further protect the water quality of the Chesapeake Bay and local streams and tributaries.

For the longest time, Maryland and its neighbors in the Northeast have implemented some of the toughest air pollution controls in the country. Upwind sources from Midwestern and Southern power plants and motor vehicles must accept responsibility for, and take actions to control, the air pollution they dump on Maryland and other downwind states. Our Clear Skies Plus approach is a call to action for those areas of the country to do their fair share.