Seguin Water Hardness & Quality Report (2026)

The City of Seguin Water Utilities provides drinking water to approximately 30,000 residents in Guadalupe County, Texas, primarily within the city limits and surrounding areas. Water sources include groundwater from the Edwards Aquifer and Carrizo-Wilcox Aquifer, supplemented by surface water from the Guadalupe River. Treatment occurs at the city's Water Treatment Plant, which processes raw water through coagulation, sedimentation, filtration, and disinfection. Annual Consumer Confidence Reports are published at seguintexas.gov/821/Water-Quality, detailing compliance with Texas Commission on Environmental Quality (TCEQ) regulations.

The supply originates in the Guadalupe River watershed, spanning the Edwards Plateau and coastal plain regions. Water infiltrates through Cretaceous limestone formations of the Edwards Aquifer, a prolific karst system with highly permeable dolomitic limestones and cavernous formations, and the Tertiary Carrizo-Wilcox sands, picking up dissolved minerals from these carbonate-rich rocks. This geology imparts a hard character through elevated calcium and magnesium from limestone dissolution, resulting in consistently mineralized water reflective of Central Texas's calcareous terrain.

Hard water in Seguin leads to scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan — hot water heaters may fail prematurely due to calcium deposits. Soap lathering is poor, leaving spots on dishes and fixtures, and laundry may feel stiff. Regular descaling of appliances, vinegar soaks for faucets, and a water softener (which can prevent about 90% of scale) are recommended. Water quality reports confirm compliance with EPA standards, though third-party analyses note 10 contaminants exceeding health guidelines, including disinfection byproducts such as trihalomethanes and haloacetic acids; no PFAS or lead action level exceedances are reported in recent TCEQ-assessed CCRs.