San Luis water system exceeds disinfection byproduct limits

The municipal water system in San Luis, Arizona, recorded levels of total trihalomethanes (TTHM) exceeding state limits during the second quarter of the year. Consequently, the Arizona Department of Environmental Quality (ADEQ) issued a Violation Notice to the municipal government on August 19.

Two sampling points in the distribution system showed concentrations of 0.089 and 0.088 milligrams per liter, surpassing the maximum allowable limit of 0.080 milligrams per liter. Trihalomethanes are byproducts that can form during the drinking water disinfection process, and their presence is monitored due to potential risks associated with long-term exposure to elevated levels.

The City of San Luis has informed residents and implemented measures to reduce concentrations within the distribution network. Officials noted that TTHM increases can occur in various Arizona communities, particularly during months with high temperatures. To address the issue, the city is working on hydraulic infrastructure improvements, including the installation of a new water main, to increase water circulation and prevent the accumulation of these byproducts.