Total trihalomethanes (TTHMS) can form when chlorine used to disinfect water reacts with organic matter already present in the water, such as leaves or plants. Alternative disinfectants, removing organic pre-water treatment, monitoring, and filtration are all ways to reduce TTHMs in your drinking water.

Studies have shown that long-term exposure to TTHMs put people at risk of cancer, reproductive issues, and even liver, kidney, and nervous system damage. (Another reason to never drink water from the pool!)