A growing amount of unfiltered storm water flowing from the Washington area’s heavily paved landscape — some of it mingled with raw sewage — is degrading an already polluted Potomac River, an environmental group said in a report Tuesday.
The nonprofit Potomac Conservancy said chemical-laden runoff from hard surfaces like asphalt and concrete represents the fastest-growing source of pollution for the river and its tributaries, and faulted government regulators for failing to curb discharges from development.
The report is timely, said Chesapeake Bay Stormwater Network coordinator Thomas Schueler on a conference call with reporters, because next year “will be the tipping point where we either begin to really solve the storm water problem in the Potomac River basin and Chesapeake Bay, or accept inevitable and irreversible decline in those water resources.”
Both the Chesapeake and the Potomac face a host of environmental problems that have ballooned in recent decades as urban sprawl projected out from the District of Columbia.
Federal officials doubt they will meet a 2010 deadline for cleaning the Chesapeake, whose woes include a dwindling crab population and a sprawling “dead zone” with too little oxygen to support aquatic life.
Last year, the Potomac Conservancy graded the Potomac a D-plus for its high levels of pollutants and the presence of transgender, or “intersex,” fish.
Tuesday’s report, which did not grade the river, highlighted the role development plays in the waterways’ health. It cited increases in the volume of unfiltered storm water from impervious surfaces like roads, rooftops and parking lots, which carries chemicals, pesticides and pathogens directly into the water.
It laid particular blame on combined storm water-sewer systems that release sewage into waterways during periods of heavy rain.
At the same time, the Potomac Conservancy called on the Environmental Protection Agency to strengthen “historically weak and unenforceable” permits that govern how localities manage storm water runoff.
“Simply stated, the storm water permits issued by the EPA and the states fail to impose meaningful limits on stormwater pollution,” the report said.
The group advocated putting in place building practices that mirror the ability of undeveloped land to absorb and filter runoff, like creating rain gardens, porous pavements and green roofs.
Environmentalists said they see opportunity for improvement both in the large number of storm water permits up for renewal in the next two years and in the ongoing economic downturn.
“With this current economic situation, we certainly have an opportunity to get ahead of the next wave of development, and get in place some of these regulations and requirements on future development,” Potomac Conservancy President Hedrick Belin said.
