While point source and nonpoint source pollutants enter the Bay directly through land and water, 33% of Nitrogen enters the bay through the atmosphere. The airshed that affects Bay health is much larger than the watershed – it covers most of the Mid-Atlantic region. Atmospheric Nitrogen in the Chesapeake Bay is a product of mainly two sources: personal vehicles and electric plants that burn fossil fuels.

Reducing atmospheric Nitrogen is difficult because the sources are widely dispersed and difficult to pinpoint. Bay states are considering enacting air pollution controls more stringent than those specifically mandated by the national Clean Air Act Amendments. (The EPA, www.epa.gov; and
The Chesapeake Bay Program, www.chesapeakebay.net)