What is the standard residual chlorine level recommended in drinking water?

The recommended standard residual chlorine level in drinking water is 0.2 to 4.0 mg/L because this range ensures that water is adequately disinfected while minimizing potential health risks associated with higher chlorine levels. Maintaining chlorine concentration within this range helps to effectively kill pathogens and prevent microbial growth in the water distribution system.

Levels below 0.2 mg/L may not provide sufficient disinfection, which could lead to the growth of harmful bacteria, while levels above 4.0 mg/L could lead to undesirable tastes and odors, or even health concerns from excessive chlorine consumption. This balance is crucial for ensuring safe drinking water that meets regulatory standards and protects public health.