(WASHINGTON, D.C.) The District Department of the Environment (DDOE) proposed a new regulatory framework for stormwater management by large development sites in the District of Columbia. The new framework, containing requirements to dramatically reduce stormwater runoff’s harmful impacts to the Anacostia and Potomac Rivers, Rock Creek, and their tributaries, includes an innovative Stormwater Retention Credit (SRC) trading program, the first of its kind in the nation.
The new regulations were published in DC Register on Friday, June 7, 2013 and are available at www.dcregs.org/Gateway/IssueList.aspx.
Under the proposal, large construction sites that trigger the requirements would install green roofs, rain gardens, permeable pavement, and other green infrastructure practices to reduce stormwater runoff. Stormwater runoff erodes District stream banks and carries trash, oil, pet waste, and other pollutants into District waterbodies.
“This new regulatory framework will transform the District’s impervious areas into a more river-friendly landscape,” said DDOE Director Keith A. Anderson. “It is a critical step toward making District waterbodies more usable and attractive for residents, businesses, and visitors. It will also go far in meeting Mayor Gray’s Sustainable DC goal of making 100% of District waterbodies fishable and swimmable by 2032.”
Specifically, sites that disturb 5,000 square feet (SF) or more of land would be required to retain the stormwater from a 1.2 inch storm, as required by the Municipal Separate Storm Sewer System (MS4) Permit. The MS4 Permit also requires the District to establish a lesser retention standard for major substantial improvement projects, which are renovations of existing structures that have a combined 5,000 SF footprint and for which the project cost exceeds 50% of the pre-project value of the structure. These major substantial improvement projects are required to retain the volume from a 0.8 inch storm.
To help regulated sites meet these requirements and achieve voluntary stormwater retrofits on unregulated properties, the proposal allows regulated sites to achieve 50 percent of their required stormwater retention volume offsite, using privately tradable SRCs or by paying an in-lieu fee to DDOE. DDOE expects SRCs to be a more cost-effective option for regulated sites.
Approximately 43 percent of the District’s land area is composed of rooftops, parking lots, and other impervious surfaces and only 1 percent of the District’s land area would trigger these regulations in a typical year. Therefore, property owners who do not trigger the regulations will have tremendous opportunity to voluntarily retrofit their properties in order to generate SRCs for sale.
By creating a market for stormwater retrofits on properties that otherwise would not be retrofitted in the near future, SRC trading offers a range of impressive sustainability benefits. In addition to having the potential to reduce compliance costs and maximize flexibility for regulated sites, SRC trading can result in a significant increase in total stormwater retention in the District and provide other benefits to District waterbodies, compared to strictly requiring regulated sites to achieve retention on site. By increasing the installation of green infrastructure, SRC trading can also provide other sustainability benefits, including new job opportunities, improved community health, and attractive new green spaces across the city.
This is the second formal comment period on the regulatory framework, which extends through Monday, July 8, 2013. In April 2013, DDOE conducted a 30-day informal comment period on the rule and held a 90-day first formal comment period from August 10, 2012 through November 8, 2012.
Additional information on the proposal is available at ddoe.dc.gov/proposedstormwaterrule.
CONTACT: Donna Henry (DDOE) 202.299.3338; firstname.lastname@example.org