What are disinfection by-products, and are they an issue in the SWS?
Disinfection by-products (DBPs) are chemical compounds formed when chlorine is added to water with organic material in it. All natural waters have some organic material in them, and generally waters that are more turbid (dirty) have more organic material. DBPs are a concern whenever chlorine is added to drinking water, whether in the Safe Water System or in a large-scale water treatment plant in the United States, because some studies have suggested that ingestion of DBPs in water over a lifetime may be associated with a very low risk of cancer. However, this risk is very small (1 in 100,000 people over 70 years is what the WHO considers when establishing their drinking water guidelines (1996)). In areas where many people, and many children, have diarrheal diseases caused by unsafe drinking water, the risk of cancer from THMs is miniscule compared to the risk of death or stunting from diarrheal diseases. The World Health Organization is very clear on the importance of microbiologically
