Sonora, CA—Tuolumne Utilities District (TUD) customers can find out the quality of water coming from their taps, as the district has released its Annual Water Quality Report.
Also known as “The Consumer Confidence Report,” it summarizes water quality monitoring and testing for the 2025 calendar year and is required under state regulations to provide customers with an overview of the water quality. The report addresses the district’s 11 treated water service regions, comprised of nine surface water treatment plants and nine operational wells. TUD’s surface water is supplied from the South Fork of the Stanislaus River at Lyons Reservoir via the Tuolumne Main Canal under a contract with Pacific Gas and Electric Company (PG&E).
“TUD’s dedicated staff works diligently to supply safe and reliable water to homes and businesses. The District maintains a strong commitment to producing drinking water that meets or exceeds all state and federal standards and takes great pride in delivering quality water at a fair value,” stated TUD officials.
Tuolumne Utilities District’s 2025 water quality report confirms compliance with federal and state standards, highlighting sources from Sierra snowpack and groundwater, treatment processes, including chlorine disinfection, and efforts to monitor contaminants such as lead, PFAS, and disinfection by-products. The district emphasizes community participation, infrastructure maintenance, and ongoing testing to ensure safe, reliable drinking water. Some of the areas focused on in the report included impacts to public health, water safety, and regulatory compliance:
Water Quality and Safety Compliance
- The Tuolumne Utilities District (TUD) consistently meets or exceeds all federal and state water quality standards. Regular testing for a wide range of contaminants—including bacteria, metals, organic chemicals, and radioactive substances—shows that all detected substances are below their respective maximum allowed levels. There were no violations of health-based standards in 2025, ensuring the water is safe to drink.
Source and Treatment of Water
- TUD’s water comes primarily (96%) from surface water sources—Lyons Reservoir and Pinecrest Lake—delivered via the Tuolumne Main Canal, with the remaining 4% from groundwater wells. The water undergoes a multi-step treatment process: screening, coagulation, filtration, disinfection (primarily with chlorine), storage, and continuous quality monitoring to ensure safety and compliance.
Lead and Copper Safety
- The district has completed a comprehensive inventory of service lines and confirmed that there are no lead or galvanized lines requiring replacement in its distribution system. All service lines are made of non-lead materials (galvanized steel, copper, or PVC). Tap water samples for lead and copper are well below regulatory action levels, minimizing health risks associated with these metals.
Contaminant Awareness and Health Information
- The report details potential contaminants (microbial, inorganic, organic, radioactive, and PFAS) and emphasizes that the presence of contaminants does not necessarily indicate a health risk. Special health information is provided for vulnerable populations (infants, the elderly, and immunocompromised individuals), and resources are offered for further guidance.
Community Engagement and Water Conservation
- TUD encourages public participation through regular board meetings and provides practical water conservation tips. Customers are urged to report leaks, avoid cross-connections, maintain plumbing, and use water efficiently. The report also highlights the importance of proper disposal of fats, oils, grease, and medications to protect water quality and infrastructure.
Click here to review the entire report or get a printed copy by contacting TUD Customer Service at (209) 532-5536.
