The
Surface Water team has contributed substantially to our knowledge
about coal tar sealants and to the current City of Austin ban
on the use of coal tar sealants.
We completed a series of biological studies assessing the effect
sealants have on streams, including a recent publication in the
Journal
of the North American Benthological Society and a USGS
fact sheet.
We also evaluated the rate at which coal tar
sealant wears off parking lots in Austin using photographic
analysis. We worked extensively with the New York Academy
of Sciences on their comprehensive 2007 report on PAHs in New
York Harbor, which found that coal tar sealants were one of the
primary sources of PAHs to the Harbor (read
report). We continue to monitor background PAH levels in Austin's
streams receiving water bodies and will report on effects of the
citywide ban in 2010.
Chironomidae, Tanypodinae
In the COA field study on the effects of coal tar sealant on stream ecosystems, we found that sediment-dwelling midges (Chironomidae) were the most consistently degraded group of organisms.