Telling the Truth about RTS

For years (also known as Pavement Technology Coatings Council) has been battling misinformation and exaggerations from the U.S. Geological Survey (USGS) in Austin, TX, that has sometimes resulted in localized bans of refined tar sealer (RTS). In addition to its efforts educating communities and legislators throughout the country, this year alone has filed three Data Quality Act (DQA) challenges with a fourth DQA in the works.

In September,’s efforts received scientific support from two presentations at the International Symposium on Polycyclic Aromatic Compounds in Corvalis, OR. The research that formed the backbone of the presentations was funded by but the scientists conducting the research are outside the organization.

Use of Receptor Models to Evaluate Sources of PAHs in Sediment used data obtained from the USGS, via the Freedom of Information Act, to replicate published USGS modeling and test the results against both a negative control and a model run using different input parameters for RTS. The full presentation is available at, but one of its conclusions is that the USGS hypothesis that RTS is a significant source of PAHs in sediments is not supported by receptor models (commonly used mathematical models intended to help identify sources of environmental pollution).

A second presentation, Risk Assessment for Coal-Tar-Based Pavement Sealants, reviewed a recently completed peer review of a risk assessment collaboration between Baylor University and the USGS. The peer review documents the exaggerations and unexplained violations of risk assessment guidance in the Baylor/USGS effort.

The point is that has been, and still is, at the forefront of defending the sealcoating industry – and as the group has said all along the study results on which the USGS refined-tar witch hunt is based are at best blown out of proportion and at worst intentionally misrepresented to the industry and the country.

In addition to its own analysis of USGS studies now has the backing of scientists outside the organization – independent corroboration of what has been telling us all along.