What are trihalomethanes (THMs) primarily formed from?

Trihalomethanes (THMs) are primarily formed from the reaction of chlorine or bromine with organic matter present in water. When chlorine or bromine is used as a disinfectant in water treatment processes, it reacts with natural organic materials, such as decomposing plant matter, which are commonly found in surface waters. This reaction leads to the formation of THMs, which are a class of disinfection byproducts that can have health implications if consumed in large quantities.

Understanding the formation of THMs is crucial for water operators, as it highlights the need for careful management of disinfection processes and monitoring of water quality. This ensures that while pathogens are being effectively eliminated, the formation of potentially harmful byproducts is minimized. Proper treatment techniques, such as the use of activated carbon and optimizing chlorine dosing, can help reduce THM levels in treated water, thus maintaining compliance with regulatory standards and safeguarding public health.