What are the minimum chlorine residuals of free and total in the far reaches of the distribution system?

The minimum chlorine residuals of free and total in the far reaches of the distribution system are essential for ensuring water safety and pathogen control. The recommended levels, indicated in your chosen answer, are designed to provide adequate disinfection while preventing the regrowth of bacteria and ensuring that the water remains safe for consumption all the way through the distribution network.

A free chlorine residual of 0.2 mg/L and a total chlorine residual of 0.5 mg/L are seen as the baseline that balances effective microbial control with avoidable nuisances like taste and odors. This level helps maintain appropriate disinfection levels without posing significant aesthetic issues for consumers.

In contrast, other options either suggest lower levels that may not provide sufficient disinfection or higher levels that might lead to taste and odor concerns. Maintaining the appropriate chlorine levels in the far reaches of the distribution system is crucial for public health protection and operational reliability of the water supply.