Section R. 325.10611 - Filtration and disinfectionRule 611.
(1) A supplier of a public water system shall comply with R 325.10807, R 325.10808, R 325.10812, R 325.10813, R 325.10816, R 325.10817, R 325.10818, R 325.10819, R 325.10820, and R 325.10822, shall demonstrate a safe microbiological water quality history, and may be required to demonstrate stability in other measurements of water quality; or the supplier shall provide complete treatment.(2) The department may grant a deviation from subrule (1) of this rule if the supplier can demonstrate that the system is capable of producing finished water that meets state drinking water standards applicable to systems using only ground water not under the direct influence of surface water.(3) Suppliers of subpart H systems shall comply with the treatment techniques of this rule, R 325.10611a, R 325.10611b, R 325.10611c, the sampling requirements of R 325.10720, the reporting and recordkeeping requirements of R 325.10720a and R 325.11506, except where noted, and the disinfection profiling and benchmarking requirements in R 325.10722. The treatment technique requirements consist of installing and properly operating water treatment processes that reliably achieve all of the following applicable removal or inactivation percentages between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at thefirst customer:(a) Not less than 99.9% (3 log) inactivation or the removal of giardia lamblia cysts and not less than 99.99% (4 log) inactivation or the removal of viruses.(b) A 99% (2 log) removal of cryptosporidium oocysts for systems serving 10,000 or more people. This subdivision applies to subpart H systems serving 10,000 or more people until December 31, 2004 and applies to all subpart H systems beginning January 1, 2005.(4) If a supplier of a public water system does not currently provide complete treatment and if the department determines that a system requires complete treatment either under subrules (1) and (2) of this rule or because the system uses surface water or groundwater under the direct influence of surface water, then the supplier shall provide complete treatment within 18 months of the department's determination and shall provide interim disinfection and monitoring as considered necessary by the department.During the interim disinfection period, systems requiring complete treatment under subrules (1) and (2) of this rule shall demonstrate safe microbiological water quality. Subpart H systems are subject to subrule (3) of this rule within 18 months or until treatment is installed, whichever occurs first. During the interim disinfection period, subpart H systems shall also comply with both of the following provisions: (a) The supplier shall collect at least 1 sample from the source water every 4 hours while the source is being utilized and have the sample analyzed for turbidity.(b) If the result of 1 or more samples taken under subdivision (a) of this subrule is more than 1 ntu, then within 24 hours of the determination that a turbidity measurement is more than 1 ntu, the supplier shall collect at least 1 sample near the first service connection and have the sample analyzed for total coliform. Sample results from the coliform monitoring shall be included in determining compliance with the total coliform standard.Mich. Admin. Code R. 325.10611