This report discusses the concentration of known hazardous chemicals in Waller Creek, and compares them to accepted levels.Barton Springs is an environmentally-sensitive area which provides habitat for two endangered aquatic salamander species, supplies water to Barton Springs pool, and represents the primary discharge point for the Barton Springs segment of the Edwards Aquifer, a sole-source aquifer for the Austin area. DDT, DDD, DDE, and a list of polycyclic aromatic hydrocarbons (PAH) are toxic pollutants that have been monitored in the sediment at Barton Springs for at least 15 years. Trends of these pollutants over time were analyzed at Barton Springs and current concentrations of the pollutants present within the springs were compared to concentrations of the pollutants in sediment samples collected throughout Austin in 2013 and 2014. DDT, DDD, and DDE were not pollutants of concern for Barton Springs; however, PAH including benzo(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, chrysene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene have risen in concentration beginning in approximately 2006. While many samples at Barton Springs have not contained samples above probable effect concentration levels, investigation is warranted to determine why the PAH concentrations increased. The initial concern of this report was to address sediment pollution at Barton Springs but additional sites of concern were identified upon comparison of pollutant concentrations at Barton Springs to concentrations throughout Austin in 2013 and 2014. Most notably, sediment samples collected within the Harper’s Branch watershed indicate chronically toxic sediments and an investigation for a source should be conductedWaller Creek Working Grou
