R 325.11110 Distribution systems; flushing, disinfection, and water analysis.

Rule 1110. (1) Proper techniques shall be followed during construction to keep water mains clean and dry. New water mains shall be flushed thoroughly before disinfection. (2) Disinfection of new water mains is required. (3) Before placing a new water main in service, all of the following shall occur: (a) Before collection of each bacteriologic sample, heavily chlorinated water shall be flushed from the main and appurtenances until the chlorine measurements in the water leaving the main is absent or no higher than that normally maintained in the distribution system. (b) Not fewer than 2 consecutive water samples for bacteriological analysis shall be collected 24 hours apart unless an alternate interval is approved by the department. (c) An analysis shall not indicate the presence of coliform. Analyses for other contaminants may be required if the department has reason to believe that these contaminants are present. (4) A public water supply in which all or part of a distribution system is not in year-round service shall comply with subrules (2) and (3) of this rule before placing the system into service for the season.