In 2021, The Texas Water Company (TWC) conducted a risk assessment to identify significant points of entry for PFAS (per- and polyfluoroalkyl substances) into their surface and groundwater sources. The evaluation focused on the immediate surface area as well as the Trinity Aquifer in the regions outside of TWC’s service area. The study was especially concerned about the potential impacts of military installations situated around San Antonio. Fortunately, the report concluded that no significant risks were identified at that time. However, to proactively monitor for PFAS, TWC began a voluntary sampling program in May 2022. The program aims to take PFAS samples across all its systems using the same methodology and area sample sites approved by the Environmental Protection Agency (EPA).
It is important to note that TWC’s voluntary sampling program differs from the sampling performed under the EPA’s Unregulated Contaminant Monitoring Rule (UCMR) program. The UCMR program is conducted to assist the EPA in identifying drinking water quality risks. In the third round of UCMR (2013-2015), eight of TWC’s groundwater wells and one of its surface water plants were tested for PFAS, but no PFAS was detected. In addition to its own sampling program, TWC will participate in the upcoming round of UCMR scheduled between 2023 and 2025, including PFAS sampling.