What is the minimum free chlorine level that should be maintained in the water system?

The minimum free chlorine level that should be maintained in the water system is crucial for ensuring water safety and disinfection effectiveness. A level of 0.25 mg/l is widely recognized as the minimum necessary to provide adequate disinfection while still being safe for consumers. Maintaining this concentration helps to effectively kill pathogens and keep the water supply free from harmful microorganisms that may be present.

Regulatory standards and best practices recommend this minimum level for several reasons, including the balance between disinfection and potential chlorine taste or odor complaints from consumers. Although higher levels of chlorine, such as 1 mg/l or 1.25 mg/l, may provide additional disinfection capacity, they can also lead to increased consumer dissatisfaction due to taste and smell issues. Thus, the emphasis on maintaining a very specific minimum level, like 0.25 mg/l, helps ensure effective water treatment while minimizing negative feelings towards the finished water.