Call it a collaboration of infiltration—the U.S. Environmental Protection Agency and the City of Philadelphia agreed yesterday to become partners in a 25-year plan to use green infrastructure to manage stormwater runoff. In a signing ceremony at the Fairmount Water Works, EPA Administrator Lisa Jackson joined Mayor Nutter, PWD Commissioner Howard Neukrug and other officials to assure the EPA’s support for Green City, Clean Waters. The long-term plan aims to restore water quality in our local rivers and streams by absorbing rain water into the ground; green infrastructure such as tree trenches, green roofs and rain gardens mimic natural processes that intercept and infiltrate rain water before it enters the sewer.

Philadelphia Inquirer reporter Sandy Bauers expanded on the issue and the economic advantages of green infrastructure in today’s front-page article:

“Philadelphia’s problem is that about 60 percent of the city’s sewers are a combined system that carries both sewage and storm water. During heavy rainfall, the system overflows, and untreated water containing raw sewage, litter, road pollution, and other substances spurts from more than 150 overflow pipes into streams and rivers. The overflows total about 14 billion gallons a year. Many other large cities have decided to build massive—and hugely expensive—underground tunnels to solve the problem. Washington proposed three of them, the largest eight miles long and 23 feet in diameter. Philadelphia had considered it, but then realized it might be looking at the wrong end of the pipe. Instead of managing what came out of the sewer system, perhaps it could manage the water before it enters the system.”

More photos from the signing ceremony after the jump.

Officials present at the signing ceremony yesterday included (from left to right): Shawn Garvin (Administrator for EPA’s Mid-Atlantic Region), Mayor Nutter, U.S. Rep. Allyson Y. Schwartz, EPA Administrator Lisa Jackson, Deputy Mayor Rina Cutler and PWD Commissioner Howard Neukrug.