To what (ppm) must cargo water obtained from an unapproved source be chlorinated after a 30-minute contact time?

Cargo water obtained from an unapproved source must be chlorinated to a concentration of 2.0 ppm after a 30-minute contact time to ensure effective disinfection. This chlorination level is established to reduce the risk of waterborne pathogens and contaminants that may be present in unapproved sources.

Chlorine is a powerful disinfectant, and the concentration of 2.0 ppm is considered sufficient to eliminate a wide range of microorganisms, including bacteria and viruses, which are of concern in cargo water. The specified contact time of 30 minutes allows for adequate interaction between the chlorine and potential pathogens, ensuring that they are effectively inactivated before the water is deemed safe for use.

Maintaining this standard is crucial in operational settings where water quality cannot be guaranteed due to the source, making proper chlorination essential to safeguarding health and safety.