Millions of Gallons of Polluted Runoff
I live in Arlington County, Virginia where hard surfaces like roads and rooftops that are impervious to water make up 42 percent of the landscape. Existing, new, and redevelopment in Arlington, Virginia increase the amount of surfaces like parking lots and rooftops that are impermeable to rainwater.
What does that mean?
Essentially, when it rains, the rainwater is unable to soak into the ground. As a result, large volumes of rainwater may run along parking lots, rooftops, or streets. As the runoff moves over these hard surfaces, it can pick up pollutants like heavy metals before flowing into storm drains and untreated into local rivers and streams.
It doesn’t take very much impervious surface to significantly impact water quality. In fact, in areas with 25 percent impervious cover, waterways have lost most of their biological diversity [pdf]. A 2011 assessment of streams in Arlington County found that 66 percent had marginal or poor in-stream habitat conditions, an important measure of the ecological health of a stream.
Increased polluted runoff flowing into Arlington streams have resulted in higher stream temperatures, flash floods, and concentration of pollutants. For example, Holmes Run in Fairfax, VA has experienced frequent flooding, severe stream bank erosion, and increased sedimentation as a direct result of polluted runoff.
Right now, the Environmental Protection Agency (EPA) has the opportunity to update its programs to manage polluted runoff from urban areas by creating standards that require new building projects to capture rain where it falls before it becomes polluted runoff. Requiring runoff to be managed onsite may create incentives for green roofs, rain gardens, or green streets that also provide multiple benefits to communities. Additionally, EPA is also considering how to better target sources runoff to protect clean water and sensitive environments that are most likely to be impacted by polluted runoff. Unfortunately, the Agency is years behind schedule to propose a new rule.
Show your support for the EPA’s efforts to strengthen its stormwater programs and better protect our rivers and streams. Send a letter to EPA Administrator Gina McCarthy expressing concern over the delays and asking her to take the lead in moving forward on these critical updates to protect clean water and public health.