scope:

This standard describes chlorination materials, procedures, and requirements for disinfection of new treatment facilities and existing water treatment facilities temporarily taken out of service for cleaning, inspection, maintenance, painting, repair, or any other activity or event that might lead to contamination of water. Typically, this standard applies to treatment components, including filter basins, filter media, clearwells, pump suction wells, and associated piping and appurtenances located downstream from the filter influent, or from the first point of application of disinfectant in the treatment process, or all portions of a facility if no primary disinfection is provided. The disinfection method employed is surface contact with a high-strength chlorine solution for a specific time period. The absence of total coliform bacteria in addition to the use of proper disinfection practices is confirmation that the disinfection process has been accomplished in compliance with this standard.

Purpose

The purpose of this standard is to define the minimum requirements for the disinfection of water treatment plants, including facility preparation, application of chlorine to the interior surfaces of water treatment units, and sampling and testing for the presence of total coliform bacteria.