Section R. 325.11902 - Classification of distribution systems and other public water suppliesRule 1902. The following classifications are assigned to public water supplies:
(a) Class S-1: Distribution systems for community supplies serving a population greater than 20,000.(b) Class S-2: Distribution systems for community supplies serving a population from 4,000 to 20,000.(c) Class S-3: Distribution systems for community supplies serving a population from 1,000 to 4,000.(d) Class S-4: Distribution systems for community supplies serving a population of less than 1,000.(e) Class S-5: Nontransient noncommunity water supplies with no treatment or community supplies with no treatment and a distribution system limited in extent.Mich. Admin. Code R. 325.11902