Flushing/Disinfection of Potable Water System

Section 890 Section 890.1180  Flushing/Disinfection of Potable Water System New or repaired potable water systems shall be flushed or disinfected prior to use as follows: a)         Chlorinated Water Supply.  If the potable water supply serving the water supply system is chlorinated, e.g., a community water system, the water supply system, or appropriate repaired portion, shall be flushed with clean, potable water until no dirty water appears at the point of outlet. b)         Non-Chlorinated Water Supply.  The pipe system shall be flushed with clean, potable water until no dirty water appears at the point of outlet. 1)         The system, or part of the system, shall be filled with a chlorine solution containing at least 50 parts per million of chlorine and shall be valved off and allowed to stand for 24 hours, or the system, or part of the system, shall be filled with a chlorine solution containing at least 200 parts per million of chlorine and be allowed to stand for three hours. 2)         Following the required contact (standing) time, the system shall be flushed with clean, potable water until the chlorine level in the water discharging from the system is within acceptable limits for potable water, i.e., generally until the water has no detectable chlorine odor. 3)         To ensure that the water supplied by the water system is safe for drinking, a bacteriological examination of a water sample taken from the water supply system shall be secured.  This examination shall be performed by a laboratory certified in accordance with 77 Ill. Adm. Code 465.  The chlorine residual in any water sample collected for examination shall not exceed 4 parts per million (or 4 milligrams/liter) for a reliable laboratory result.  If the examination reveals that contamination still persists in the system, the procedure for disinfection shall be repeated.