At what level are free chlorine residuals typically maintained in a distribution system?

Free chlorine residuals in a distribution system are typically maintained at a level of around 1.0 mg/l to ensure effective disinfection while also preventing microbial growth within the water supply. This concentration serves as a safeguard against pathogens and helps maintain water quality from the treatment plant to the point of consumption.

Maintaining free chlorine at this level strikes a balance where sufficient disinfection is achieved without the risk of taste or odor issues becoming prominent. Adequate chlorination also provides a buffer against contamination events in the distribution system. Overall, a free chlorine residual of 1.0 mg/l ensures that the water remains safe for public consumption while adhering to regulatory standards for water quality.