HB 156 directs the Texas Commission on Environmental Quality (TCEQ) to conduct a study on protecting public drinking water supply systems and wastewater treatment facilities from various threats. These threats include electrical outages, catastrophic weather events, criminal conduct, climate change effects, and other potential service disruptions. TCEQ is required to consult with other state agencies or stakeholders as necessary and must submit a report with recommendations for legislative or other actions to the governor and legislature by September 1, 2026.