I came across this report I read several years ago that is just as pertinent today as it was in 2008 and thought I would share it with the readers of this site.
The National Research Council of the National Academies, with nearly 150 years of Congressional authorization on science, medicine and engineering, authored a report, entitled “Urban Stormwater in the United States” on the status of stormwater science and regulations in 2008. Their byline is “Advisors to the Nation on Science, Engineering and Medicine.”
The entire section is included since some still claim a different perspective of what transpired in Austin:
The City of Austin’s encounter with coal tar-based asphalt sealants provides an illustration of the types of products contributing toxins to stormwater discharges that could be far better controlled at the production or marketing stage. {emphasis added} Through detective work, the City of Austin learned that coal tar-based asphalt sealants leach high levels of polycyclic aromatic hydrocarbons (PAHs) into surface waters (Mahler et al., 2005; Van Metre et al., 2006). The city discovered this because the PAHs were found in sediments in Barton Springs, which were in turn leading to the decline of the endangered Barton Creek salamander (Richardson, 2006). By tracing upstream, the city was able to find the culprit—a parking lot at the top of the hill that was recently sealed with coal tar sealant and produced very high PAH readings. Further tests revealed that coal tar sealants typically leach very high levels of PAHs, but other types of asphalt sealants that are not created from coal tar are much less toxic to the environment and are no more expensive than the coal tar-based sealants (City of Austin, 2004). As a result of its findings, the City of Austin banned the use of coal tar-based asphalt sealants. Several retailers, including Lowes and Home Depot followed the city’s lead and refused to carry coal tar sealants. Dane County in the State of Wisconsin has now also banned coal tar sealants.
For reasons that appear to inure to the perceived impotency of TSCA and the enormous burdens of restricting chemicals under that statute, EPA declined to take regulatory action under TSCA against coal tar sealants (Letter from Brent Fewell, Acting Assisting Administrator, U.S. EPA, to Senator Jeffords, October 16, 2006, p. 3). Yet, it had authority to consider whether this particular chemical mixture presents an “unreasonable risk” to health and the environment, particularly in comparison to a substitute product that is available at the same or even lower price.”