More than half a million gallons of untreated wastewater surged into the Guadalupe River near Lake Dunlap early Wednesday after storms knocked out power at a New Braunfels Utilities facility, according to the utility. NBU estimates roughly 550,000 gallons overflowed between about 1 a.m., when the outage hit, and 4 a.m., when power was restored and the spill stopped. Crews were sent in the pre-dawn hours to contain the release, start cleanup work and begin water sampling.
In a water notice posted online, New Braunfels Utilities said the outage at the Rio Bar Screen Facility at 470 Rio Lane led to an unauthorized discharge into the river north of Lake Dunlap. After power came back, crews removed debris, applied disinfectant to affected ground areas and launched upstream and downstream water-quality sampling. NBU also said it is coordinating with the city, nearby agencies and downstream water providers while it evaluates additional mitigation and resiliency steps to reduce the risk of a repeat.
NBU spokesperson Reagan Peña told the San Antonio Express-News the wastewater "was still coming in" and backed up through a manhole when the lift station could not move it. The Express-News also reported that a spokesperson for the Texas Commission on Environmental Quality said NBU reported the spill and that the state agency has opened an investigation. The paper placed the overflow near a filtering facility on the southeast edge of the city.
Regulatory Review and Environmental Risk
Sanitary sewer overflows are reportable events that can trigger TCEQ sampling, documentation and, if needed, enforcement or corrective orders. The Texas Commission on Environmental Quality publishes guidance and reporting forms for accidental discharges and sanitary sewer overflows and oversees investigations intended to protect water quality and public health. Regulators will review sampling data from the incident to determine whether further remediation, penalties or other actions are required.
What River Users and Residents Should Know
Both NBU and local reporting say river flow and storm runoff likely diluted the wastewater and helped move it downstream, and the utility has said its drinking water system was not affected. Still, officials are urging people to follow local river-use guidance and avoid the stretch near Lake Dunlap until test results show conditions have returned to normal. Downstream providers have been notified, and NBU will continue to monitor the river until sample results fall back within acceptable ranges, the San Antonio Express-News reported.
Next Steps
New Braunfels Utilities said it will continue sampling the Guadalupe River, wrap up cleanup where the overflow traveled and study additional resiliency measures aimed at preventing power-related overflows in the future. The utility has provided a customer phone line for questions and said it will post updates if new concerns emerge. The pace of TCEQ’s review will depend on sampling results, and the investigation could take anywhere from several days to weeks depending on what regulators find and any follow-up work they require.
