EPA Approves New Performance Standards for D.C. Storm Water

The U.S. Environment Protection Agency this week announced new permit conditions for managing storm water in Washington, D.C.

“This permit includes a number of green performance measures for preventing storm water, along with the pollutants and trash it carries, from washing into local waterways,” said EPA Regional Administrator Shawn M. Garvin. “Moreover, this builds on efforts the district has already undertaken and is a major step forward in reaching our goals for restoring the Anacostia River and Chesapeake Bay.”

Under the Clean Water Act, urbanized areas like the district are required by federal law to have permits covering their discharges. The new permit requires the district to take sustainable steps promoting green infrastructure, including:

• Requiring a minimum of 350,000 sq ft of green roofs on district properties;
• Planting at least 4,150 trees annually and developing a green landscaping incentives program;
• Retaining 1.2 in. of storm water on site from a 24-hour storm for all development projects of at least 5,000 sq ft;
• Developing a storm water retrofit strategy, and implementing retrofits over 18 million sq ft of drainage of impervious surfaces;
• Developing consolidated implementation plans for restoring the impaired waterways of the Anacostia and Potomac Rivers, Rock Creek, and the Chesapeake Bay; and
• Preventing more than 103,000 lb of trash annually from being discharged to the Anacostia River.

EPA said the new permit conditions were necessary because impervious surfaces in the district, such as roads, rooftops and parking lots, channel storm water directly into local streams and rivers. Improperly managed storm water runoff damages streams, causes significant erosion and carries excessive pollutants, like nitrogen, phosphorus, sediment, toxic metals and solvents, downstream and into the Chesapeake Bay. This permit aids the district in meeting its Chesapeake Bay pollution reduction targets and its Watershed Implementation Plan.

The permit, fact sheet and response to comments are available online.

Source: U.S. EPA