Environmental Commission recommends lowering toxicity levels in pavement

In 2005, Austin passed an ordinance banning the use of coal tar pavement products due to their use of polycyclic aromatic hydrocarbons. PAHs, which are designated by the Environmental Protection Agency as “priority pollutants,” are known carcinogenic compounds that raise the risk of cancer for children and are acutely toxic to aquatic life. Ten years after the ban took effect, testing showed a 58 percent reduction in PAH concentration in Lady Bird Lake sediments. However, elevated levels of PAH remained in Austin’s streams. “In 2015, the industry sort of changed,” Tom Ennis with the Watershed Protection Department told the Environmental Commission at its Aug. 21 meeting. He explained that new, petroleum-based sealants came on the market with a 2 percent concentration of these chemicals. Coal-based sealants had a 7 percent concentration. However, because the 2005 ordinance only explicitly prohibits coal-based sealants, there is no way to legally regulate PAH concentrations in petroleum-based products. To change that, the Environmental Commission unanimously recommended that the city limit PAH concentrations in pavement sealants to 0.1 percent by January 2020. This limit was selected based on precedent. The European Union classifies road waste with 0.1 percent PAHs or higher as hazardous waste and the Federal Aviation Administration permits pavement with 0 percent PAH content. Already 17 U.S. municipalities have ordinances limiting PAH content to this percentage. According to Ennis, commercial sealant products are widely available with concentrations well below the 0.1 percent limit. “These are known toxins to aquatic life and humans,” Environmental Officer Chris Herrington said. “If the city has to adapt, the city has to adapt.”