McKinney’s municipal water system achieved a superior rating from the Texas Commission on Environmental Quality for the year 2025, marking the highest possible recognition for water quality. The designation follows the city’s release of its annual Water Quality Report, which confirmed that every state and federal health standard was met with zero contaminant violations detected across the network. McKinney is about 7 miles west of Princeton.
The city’s Water Utilities division, part of the Public Works Department, distributes the treated water purchased from the North Texas Municipal Water District. That district sources water from six surface bodies, including Lavon Lake, Bois d’Arc Lake, Lake Texoma, and Jim Chapman Lake. The water undergoes treatment at facilities in Wylie and Leonard before reaching local customers.
Testing protocols covered more than 90 contaminants mandated by the U.S. Environmental Protection Agency. These included inorganic substances such as arsenic, barium, fluoride, and nitrate. All measured levels remained within federal limits. The report also noted that Cryptosporidium, a microscopic parasite affecting the digestive tract, was absent from all lake and treated water samples tested by the district.
Disinfection by-products, specifically total trihalomethanes and haloacetic acids, stayed within allowable limits. These compounds form when chlorine-based disinfectants react with organic material. Lead and copper testing revealed no sites exceeding federal action levels. The 90th percentile lead reading was recorded at 0.903 parts per billion, significantly lower than the 15 ppb threshold. Copper measured 0.787 parts per million, below the 1.3 ppm action level.
Regarding bacterial indicators, the highest monthly percentage of total coliform-positive samples in 2024 was 1.33 percent, well under the 5 percent violation threshold. No samples tested positive for fecal coliform or E. coli. The city reported a 9 percent water loss for the twelve months ending in December 2025, calculated as the difference between purchased water and billed amounts. This figure falls below the regional target of 12 percent.
