The Texas Commission on Environmental Quality (TCEQ) has notified the Sandy Harbor Subdivision, TX1500009, that the drinking water being supplied to customers had exceeded the Maximum Contaminant Level (MCL) for total trihalomethanes. The U.S. Environmental Protection Agency (U.S.EPA) has established the MCL for total trihalomethanes to be 0.080 milligrams per liter (mg/L) based on locational running annual average (LRAA), and has determined that it is a health concern at levels above the MCL. Analysis of drinking water in your community for total trihalomethanes indicates a compliance value in quarter four 2018 of 0.116 mg/L for DBP2-01.
Trihalomethanes are a group of volatile organic compounds that are formed when chlorine, added to the water during the treatment process for disinfection, reacts with naturally-occurring organic matter in the water.
Some people who drink water containing trihalomethanes in excess of the MCL over many years may experience problems with their liver, kidney, or central nervous systems, and may have an increased risk of getting cancer. You do not need to use an alternative water supply. However, if you have health concerns, you may want to talk to your doctor to get more information about how this may affect you.
We are taking the following actions to address this issue:
Sandy Harbor purchases its drinking water from the City of Horseshoe Bay. The City of Horseshoe Bay has also been experiencing this same issue and it has resulted in our exceedances. According to Horseshoe Bay the flood event in October 2018 brought large amounts of decaying organic material into the lake. This material increased the organic compounds in the lake water which reacted with the chlorine disinfection process at the water plant. The City of Horseshoe Bay is working with TCEQ and an engineering firm to determine best management practices for early detection and optimize treatment processes to mitigate elevated TTHM levels. City staff have begun additional training on THM formation and have developed an action plan to test daily for organic concentration to ensure corrective actions and mitigate future violations.
Please share this information with all people who drink this water, especially those who may not have received this notice directly (i.e., people in apartments, nursing homes, schools, and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail.
If you have questions regarding this matter, you may contact Gloria Broussard at 512-663-6819.
Click to Download This Notice