Monitoring Polycyclic Aromatic Hydrocarbon Concentrations in Austin, TX, After the Coal-Tar Sealant Ban

Polycyclic Aromatic Hydrocarbons (PAH) are a group of chemicals consisting of three or more fused benzene rings. Many of this group of compounds are considered Toxic Pollutants and listed as Priority Pollutants by the EPA. In 2006, the City of Austin enacted a ban on coal-tar sealant to remove a source of PAH contamination to Austin creeks. Sediment samples collected in approximately 50 of Austin’s largest watersheds from 1996 until 2010 were analyzed. The total PAH concentration of these samples was calculated as the sum of the 16 compounds found within the first EPA Priority Pollutant list. Kruskal-Wallis analysis and regression analysis were used to determine any temporal trends in Austin as a whole and at individual sites. 3-ringed PAH were significantly higher in 1996-1999 compared to 2003-2005, 2006-2008, and 2009-2010; and 4-ringed PAH were significantly higher in 1996-1999 compared to 2006-2008. Total PAH significantly decreased at Barton Creek above Barton Springs Pool from 1996 to 2010. While PAH concentrations at the majority of Austin locations were less than the Probable Effect Concentration (above which adverse effects on aquatic organisms are expected to occur), there were several sites where PAH concentrations were above urban background levels found in the literature. These sites require additional investigation to isolate and potentially remediate sources of PAH.Waller Creek Working Grou