If a contaminant exceeds this concentration, it can trigger improved treatment techniques or other requirements a utility must follow.
Chlorine is used in water purification, and as a disinfectant and antiseptic.
The presence of coliform bacteria indicates that the water is polluted and may contain disease causing organisms. When coliform bacteria are found, special follow-up tests are done to determine if harmful bacteria are present. If this limit is exceeded, the water supplier must notify the public by newspaper, television or radio. The CL for some contaminants is an average, for others it is meeting a condition for a certain percentage of the time. Disinfection A process designed to kill most microorganisms in water, including essentially all disease causing organisms.