What is the MCL for total trihalomethanes (TTHM or THM) in drinking water?

The maximum contaminant level (MCL) for total trihalomethanes (TTHMs) in drinking water is established at 0.080 mg/L. This value is set by regulatory bodies to ensure safe drinking water and reduce the risk of potential health effects associated with TTHMs, such as an increased risk of cancer and reproductive issues that arise from prolonged exposure.

TTHMs are formed when chlorine or other disinfectants used in the water treatment process react with organic matter present in the water. Regulating the concentration of these compounds is crucial, as it helps maintain the balance between effective disinfection and minimizing harmful byproducts. The set MCL serves as a benchmark that water utilities must adhere to, thereby enhancing public health safety and ensuring that the drinking water meets acceptable quality standards.