A minimum concentration of how many mg/L must be measurable throughout the water system after leaving the chlorination station?

The minimum concentration of chlorine that must be measurable throughout the water system after leaving the chlorination station is 0.2 mg/L. This standard ensures that there is sufficient residual chlorine present to effectively disinfect the water as it travels through the distribution system. Maintaining a measurable level of chlorine is crucial for combating microbial contaminants and ensuring the safety of drinking water.

A concentration of 0.2 mg/L is considered effective in maintaining disinfection, as it helps to provide a buffer against potential contamination that could occur during water distribution. If the chlorine level were set too high, it might lead to unpleasant taste or odor, while a level that is too low might not effectively control pathogens. Therefore, a minimum of 0.2 mg/L strikes the right balance for ensuring water safety without compromising taste or palatability.