McKinney’s municipal water system achieved a superior rating from the Texas Commission on Environmental Quality for its performance in 2025. The designation represents the highest possible grade available under state standards. The city’s Water Quality Report, released recently, confirmed that the water supply met every federal and state health requirement with zero detected violations across the distribution network.
McKinney purchases treated water from the North Texas Municipal Water District. That district draws from six surface water sources, 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 customers. McKinney is located approximately 7 miles south of Melissa.
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 detected levels remained within federal limits. The report noted that Cryptosporidium, a microscopic parasite, was absent from all lake and treated water samples analyzed by the district.
The system also remained within limits for disinfection by-products, specifically total trihalomethanes and haloacetic acids. These compounds form when chlorine-based disinfectants react with organic material. Lead and copper tests showed no sites exceeding federal action levels. The 90th percentile lead reading was recorded at 0.903 parts per billion, while copper measured 0.787 parts per million. Both figures are well below the respective action levels of 15 parts per billion and 1.3 parts per million.
Regarding bacterial indicators, the highest monthly percentage of total coliform-positive samples in 2024 was 1.33 percent. This figure fell below the 5 percent threshold that triggers a violation. No samples tested positive for fecal coliform or E. coli. The city reported a water loss rate of 9 percent for the 12 months ending in December 2025. This metric, which calculates the difference between purchased water and billed amounts, was below the regional target of 12 percent.
