How long must chlorine remain in disinfecting tanks before being flushed out?

Chlorine is a critical component in the disinfection process of water treatment, and its effectiveness relies on proper contact time with the water being treated. The recommended duration for chlorine to remain in disinfecting tanks before being flushed out is 24 hours. This time frame allows for sufficient chlorine levels to effectively kill pathogens and provide a reliable barrier against bacteria, viruses, and other microorganisms that can contaminate drinking water.

Having a 24-hour contact time ensures that the chlorine has adequate opportunity to react with all contaminants, resulting in safer water for consumption. Shortening this period may lead to insufficient disinfection, which can compromise water quality and public health.

The other time frames, while they may seem reasonable, do not meet the established standards for disinfection contact time, which is why they are less effective in ensuring the safety and potability of water.