Editors' Summary: Uncle Sam is both environmental policeman and environmental polluter. In 1970, Congress began to create a tough series of pollution control laws that govern the activities of private organizations and individuals. One of the great ironies of the early years of environmental law was that, while these deliberations were taking place, the air outside in the Capitol was often fouled by emissions from the federal government powerplant providing the electricity to light the congressional offices. The District of Columbia, required by Congress to enforce the new Clean Air Act, found itself nearly impotent in trying to clean up Congress' own pollution. The legal shield protecting the federal government as polluter was sovereign immunity, and over the last 15 years, Congress progressively lowered the shield. The author traces the history of waivers of sovereign immunity under environmental law, pointing out that the extent to which federal facilities can be held accountable varies considerably from statute to statute and activity to activity.