WASHINGTON — The EPA has announced a permit plan that would require new and redeveloped buildings in D.C. to trap 90% of the rainwater that falls on property during a storm. The plan isn't a water savings program per se — it's an effort to control stormwater and keep pollution from flowing into rivers and lakes.
Impervious surfaces like driveways, sidewalks, and streets prevent stormwater runoff from naturally soaking into the ground. Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer system or directly to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged untreated into the water bodies used for swimming, fishing and providing drinking water.
The EPA estimates that current buildings capture 0%-30% of rainwater. The new requirement would require developers to capture the first 1.2-in. of rainfall. The captured water would be filtered naturally by onsite vegetation and dirt or stored for later irrigational use.
“The innovations in this new permit are vital to restoring and protecting the health of local waterways in the District, as well as the Chesapeake Bay,” said Shawn M. Garvin, EPA mid-Atlantic Regional Administrator. “We all need to do our part, and this permit can serve as a model to other municipalities for preventing runoff from washing harmful pollutants into streams and rivers in the Bay watershed.”
Similar proposals in Virginia and Maryland have been met with resistance from developers, who have stated that it will add an enormous expense to projects.
The EPA is currently accepting comments for the new permit plan. The comment period began on April 21 and lasts 45 days, ending June 4. Following the close of public review, EPA will prepare a response and make any necessary modifications to the permit to address public comment. EPA expects to finalize the permit within three months of the close of the public review.
To view the permit online visit: http://www.epa.gov/reg3wapd/npdes/draft_permits.html.