McKinney’s municipal water system achieved its highest possible rating from state regulators for the 2025 calendar year, with officials confirming that all state and federal health standards were met and no contaminant violations occurred anywhere in the distribution network. The Texas Commission on Environmental Quality assigned the superior designation based on the city’s newly released Water Quality Report.
The city’s Water Utilities Division, which operates under the Public Works Department, 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 is treated at facilities in Wylie and Leonard before reaching customers in McKinney, which is located approximately 11 miles south of Anna.
Testing protocols covered more than 90 contaminants mandated by the U.S. Environmental Protection Agency. Results showed that levels of arsenic, barium, fluoride, nitrate, and other inorganic substances remained within federal limits. Microscopic parasites known as Cryptosporidium were not detected in any lake or treated water samples analyzed by the district. Disinfection by-products, including total trihalomethanes and haloacetic acids, also stayed below regulatory thresholds.
Lead and copper monitoring indicated no sites exceeded federal action levels. The 90th percentile reading for lead was 0.903 parts per billion, significantly lower than the 15 ppb action level, while copper measured 0.787 parts per million against a 1.3 ppm limit. In 2024, the highest monthly percentage of total coliform-positive samples was 1.33%, remaining under the 5% violation threshold. No samples tested positive for fecal coliform or E. coli.
The report noted a 9% water loss for the twelve months ending in December 2025, calculated as the difference between water purchased from the district and water billed to customers. This figure fell below the regional target of 12%. City officials stated that natural algae blooms occurring in July and August may cause earthy or grassy tastes and odors but do not impact safety. The district uses chloramines for disinfection, a method that reduces by-products while protecting against disease.
