Disinfection Byproducts in Drinking Water
Regulated disinfection byproducts and links to information about the different types, their maximum contaminant levels, health effects, and requirements for public water systems, including monitoring and sampling and operational evaluations.
Disinfection byproducts (DBPs) are chemicals that form during drinking water treatment and distribution when naturally occurring organic matter reacts with chlorine or other disinfectants used to kill pathogenic organisms. The Environmental Protection Agency (EPA) has determined that these five chemicals, or classes of chemicals, pose potential health risks and must be regulated:
- Bromate
- Chlorite
- Haloacetic acids (HAA5)
- Total trihalomethanes (TTHM)
Haloacetic Acids and Total Trihalomethanes
Community and non-transient non-community public water systems must follow the rules for HAA5s and TTHMs and the requirements for Operational Evaluations (see link below).
Operational Evaluations
Information about when and how public water systems must meet operational evaluation requirements for disinfection byproducts – in particular, haloacetic acids and total trihalomethanes.
Chlorine Dioxide and Chlorite
Public water systems that use chlorine dioxide must comply with the maximum residual disinfectant level for chlorine dioxide, maximum contaminant level for chlorite, and monitoring and sampling requirements.
Ozone and Bromate
Public water systems that use ozone must comply with maximum contaminant level for bromate, and monitoring and sampling requirements.