After a new water main is installed and pressure is tested, what should be done next?

After a new water main is installed and pressure tested, the essential next step is to fill the main with a chlorinated solution, specifically at a concentration of 25 to 50 parts per million (ppm) of free chlorine, and maintain this concentration for a minimum of 24 hours. This process is known as the chlorination of the water main.

Chlorination is crucial because it helps ensure that any potential pathogens or bacteria introduced during construction or installation are eliminated. This technique supports maintaining the microbiological quality of the drinking water system. By keeping the chlorinated solution in the main for the specified duration, you provide enough contact time for the chlorine to effectively disinfect the interior surfaces of the pipe.

After the chlorination period, it would then be appropriate to proceed with flushing the main to remove residual chlorine and any dislodged debris before performing bacterial testing to confirm the water's safety for consumption. If bacterial testing shows satisfactory results, connecting the main to the distribution system can then follow.

This systematic approach to water main installation not only prioritizes public health but also adheres to best practices in water quality management.