News | November 15, 2005

WEF, USGS Sponsor Congressional Briefing On Parking Lot Sealants

Parking Lot Sealants and Toxic Pollution in Urban Streams and its Impacts to Aquatic Life

Alexandria, VA — Recent studies by the USGS' National Water-Quality Assessment (NAWQA) have identified sealcoating – the black, shiny surface often applied to asphalt pavement – as a significant and previously unrecognized source of extremely elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) in streams. In one instance, runoff from parking lots sealed with a type of coal, tar-based sealant had PAH concentrations of 65 times higher than concentrations from unsealed parking lots. In response, the Water Environment Federation (WEF), in cooperation with the U.S. Geological Survey (USGS), is sponsoring a congressional briefing on Friday, December 2 from 9:30 a.m. to 11:30 a.m. in Room 2318 of the Rayburn House Office Building to further discuss these findings and its implications to local and federal policy.

PAHs are suspected human carcinogens and are toxic to aquatic life. Biological studies conducted by the City of Austin, Texas found a loss of species and decreased numbers of organisms at the PAH concentrations seen in Austin streams. Officials observed these effects at sites downstream from the points where sealed parking lot runoff enters the streams. Because sealants are used nationwide and the concentrations of PAHs in lakes and reservoirs across the country are increasing, this information raises important local and national policy questions about the use of sealants and methods to prevent contaminated runoff from reaching urban water bodies. The City of Austin Council is currently considering a ban on the use of coal-tar sealants.

Speakers for the briefing include:

  • Peter Van Metre, USGS Scientist: USGS findings on PAH concentrations in sealcoat runoff and trends of PAH contamination in urban areas nationwide.
  • Mateo Scoggins, Biologist, City of Austin Watershed Protection and Development Review Department: Austin's findings on how sealant impacts on aquatic life.
  • Representatives from U.S. EPA and the City of Austin: Available to answer questions and provide a context for discussion of policy issues.
The briefing is open to the public and free-of-charge.

SOURCE: Water Environment Federation (WEF) - WEFTEC