ALEXANDRIA, Va. (WUSA) - The GenOn power plant ceased operations at midnight. While the plant helped power the developing D.C. area 1950s and on, it also sent tons of air pollution into the skies over the District, Maryland and Virginia. The plant was the largest single source of air pollution in the Washington region.

Now, after 10 years of community activism, and government regulation, GenOn has closed the plant.

The first seeds of community activism against the plan started eleven years ago, Elizabeth Chimento noticed a strange residue outside. She lives within sight of the GenOn Potomac River Power Plant and was the first to raise questions about its emissions.

Current owners Gen On say publicly that they're shuttering the plant because of it's too expensive to keep it running. But the group of elected officials and residents celebrating the power plant's demise say there's more to it.

They point to Chimento, and Poul Hertel. "I'm elated because for the first time since 1946 residents of the neighborhood can actually breathe a sigh of relief knowing that they won't be in the shadows of the downwash," said Hertel.

Their curiosity grew into activism. They educated themselves about coal fired plants and emissions. Then commissioned three studies. One of the most important studies was done by a local scientist and meteorologist who found that instead of the pollutants being sent up into the atmosphere at the company said, they were actually coming down into the community, a phenomenon known as downwash.

The downwash was due in part to the short stacks... required because the plant is the flight path of national airport.

A Penn State study matched the company's coal to that grey residue... and a Harvard study connected resident's health problems, including 3000 cases of asthma and 59 deaths, to pollutants spewed out by the plant.

It'll take up to 18 months to deactivate and clean up the plant. There's no decision yet on what will become of the valuable waterfront property.

Read or Share this story: http://on.wusa9.com/1c3HaxJ