An agreement between the EPA and the District of Columbia will incorporate a variety of "green infrastructure" techniques, such as green roofs and rain gardens, into the district's stormwater discharge permit to help curb polluted runoff.
The plan, which officials said could become a model for other stormwater permits, calls for the district to undertake and monitor a number of specific actions, many of which will provide information for more-detailed plans in the future.
Instead of managing runoff after it is collected in stormwater systems, the program aims to reduce the volume runoff by planting trees and implementing "low impact development" techniques that give rainwater more opportunities to absorbed into the ground instead of being flushed into a stream.
Stormwater is a major source of degradation to the Anacostia River, which flows through the district. It also contributes to pollution in the Potomac River.
"We are going to aggressively promote and enforce low impact development for the District of Columbia," Mayor Adrian Fenty said at the Executive Council meeting in December. He said that green infrastructure, such as trees and green roofs, will not only reduce stormwater runoff, but would be aesthetically pleasing, reduce heat buildup in the city and cut energy use.
"We believe that this will probably be one of the most advanced stormwater permitting processes in the nation," Fenty said. "And hopefully, this region can continue to lead the nation."
Some elements of the plan include:
- The district will plant and maintain at least 13,500 trees by 2014 and develop a tree canopy goal for the city.
- The district will begin building and monitoring low impact development projects in the city that are aimed at reducing runoff from new construction. It will complete at least 17 projects by August 2009, and by the end of 2014, it will have created a plan to identify all of the locations in the district where various types of LID projects, such as the conversion of hardened surfaces into green spaces, are possible.
- The district will install approximately 50 rain gardens and 125 rain barrels citywide and disconnect 200 downspouts so they no longer run into stormwater systems.
- The district will develop tax credits or other incentives to promote the installation of green roofs on non-government buildings.
- During the next four years, all buildings constructed by the district's Office of Property Management-as well as all of OPM's properties that receive major renovations or rehabilitation-will include green roofs where feasible.
- The district will implement a street sweeping program aimed to removing fine particles, which are especially harmful to streams, from the road before they can wash into storm drains and local waterways.
- Special efforts will be made to keep litter and pet wastes from reaching streams through a variety of actions, such as establishing dog parks where people can walk their pets, and placing traps in stormwater systems to catch litter.
"This is the most advanced set of green infrastructure controls for urban stormwater that we have seen in the mid-Atlantic Region," said Donald Welsh, administrator of EPA Region III, which includes most of the Bay watershed. "The district's commitment to employ sustainable and measurable solutions for wet weather pollution demonstrates leadership for the Chesapeake Bay watershed."