Maine lakes and streams are particularly vulnerable to air pollution like acid rain because the state is downwind from the major pollution sources in the Midwest. For this reason, Maine's surface waters have also provided scientists with the data necessary to show how air pollution can lead to water pollution, affecting ecosystems, fish and humans. This information is especially important in a state where so much of the economy depends on natural resources.

The Senator George J. Mitchell Center for Environmental and Watershed Research, named for the senator in 2000, has been at the forefront of acid rain research for more than two decades. Based at the University of Maine and working at places like Acadia National Park and the Bear Brook Watershed-Maine, Mitchell Center staff and students are contributing to the highest levels of policy-relevant scientific research. The Tunk Mountain Watershed Study, now part of the EPA-funded Regional Long-Term Monitoring project, is one of the longest-running lake monitoring programs in the country. In recent years, data from these and other lake studies contributed to an evaluation of the 1990 Clean Air Act Amendments that Sen. Mitchell helped make a reality.

The 1990 amendments successfully reduced atmospheric emissions of sulfur dioxide, the primary compound in the formation of acid rain. As a result, acid deposition has decreased and some of Maine's lakes and ponds already show signs of recovery. Last summer, one Mitchell Center graduate student returned to sample water quality at 145 lakes that were last tested in 1984. A comparison of the 2004 data to the numbers from 1984 will allow for an evaluation of how air and water quality have changed over the last 20 years, and how influential the 1990 amendments have been. This kind of research supplies legislators with the information they need to create sound environmental policies.

It seems appropriate to recognize Sen. Mitchell's legacy this year, as the laws he fought so hard to strengthen and protect are being undermined. The most recent changes to the Clean Air Act concerning mercury pollution have prompted Maine to join nine other states in suing the Environmental Protection Agency. The suit criticizes the new rules as failing to fulfill requirements of the Clean Air Act. The other states involved in the suit are California, Connecticut, Massachusetts, New Hampshire, New Jersey, New Mexico, New York, Vermont and Wisconsin.

In his actions, Sen. Mitchell has demanded that we leave "a legacy of clean air, pure water and unpoisoned land." As we honor him this April 21, Sen. George Mitchell Clean Air Act Day, let us also support our current delegation's efforts to further his legacy and protect Maine's environment for future generations.