In an initiative that eventually could have nationwide impact, the U.S. Environmental Protection Agency (EPA), the District of Columbia Water and Sewer Authority (DC Water), and the District government announced in mid-December an agreement called "Clean Rivers, Clean District" to advance green infrastructure for urban stormwater management. In accordance with a 2005 federal consent decree, DC Water is moving forward with design and construction of a system of tunnels to capture, store, and convey combined sewer overflow (CSO) in the Anacostia River watershed but proposed extending deadlines for design and construction of tunnels in the Rock Creek watershed while it implements a Green Infrastructure Demonstration Project.

The goal appears to be to demonstrate the extent to which green infrastructure can alleviate CSO and effect compliance with the consent decree. If successful – and sustainable – the savings could be significant.

The District of Columbia already is pursuing a number of green infrastructure projects, including green streets (see related story), an urban tree canopy, and green roofs. DC Water also has undertaken its own projects promoting rain barrels, rain gardens, bio-retention areas, permeable pavers, and green roofs.

However, as part of the recently announced agreement, DC Water plans to "conduct a large-scale, multi–million-dollar green infrastructure project in the Potomac and Rock Creek watersheds for the purpose of evaluating the practicality and efficacy of implementing green infrastructure for the control of CSOs in these watersheds."

To support the demonstration project, EPA and the District of Columbia will:

• participate in developing and implementing a Green Design Challenge, which will engage the private sector and other interested parties in projects to demonstrate the practicality and efficacy of decentralized, large-scale and small-scale green infrastructure for stormwater control;
• enlist participation by public and private organizations in an effort to develop and demonstrate next-generation green infrastructure designs and techniques;
• facilitate participation by local academic institutions in various aspects of the Green Infrastructure Demonstration Project;
• actively involve the environmental community in design and development of the green infrastructure project to facilitate implementation; and
• review and provide input on DC Water's technical memoranda and reports.

To promote green infrastructure implementation nationwide, the EPA agreed to:

• communicate with EPA's Office of Research and Development (ORD) on the progress of the Green Infrastructure Demonstration Project and opportunities for ORD's involvement; and
• assist DC Water in sharing the results of the Green Infrastructure Demonstration Project so other communities can benefit from DC Water's experiences.

Such a large-scale urban experiment with green infrastructure, if successful, could change how EPA structures (or restructures) consent decrees dealing with CSOs and stormwater management. Stay tuned.

Bob Drake
bdrake@zweigwhite.com