Section R. 325.11901 - Classification of treatment systemsRule 1901.
(1) Complete treatment systems are classified based on population served by the public water supply or rated treatment capacity of the treatment system as follows:(a) Class F-1: Complete treatment systems for community supplies serving a population greater than 20,000, or with a rated treatment capacity greater than 5.0 million gallons of water per day.(b) Class F-2: Complete treatment systems for community supplies serving a population from 4,000 to 20,000, or with a rated treatment capacity from 2.0 to 5.0 million gallons of water per day.(c) Class F-3: Complete treatment systems for community supplies serving a population from 1,000 to 4,000 or with a rated treatment capacity from 0.5 to 2.0 million gallons of water per day.(d) Class F-4: Complete treatment systems for community supplies serving a population of less than 1,000, or with a rated treatment capacity less than 0.5 million gallons of water per day.(e) Class F-5: Complete treatment systems for noncommunity supplies.(2) Limited treatment systems are classified based on population served by the public water supply or rated treatment capacity of the treatment system as follows: (a) Class D-1: Limited treatment systems for community supplies serving a population greater than 20,000, or with a rated treatment capacity greater than 5.0 million gallons of water per day.(b) Class D-2: Limited treatment systems for community supplies serving a population from 4,000 to 20,000, or with a rated treatment capacity from 2.0 to 5.0 million gallons of water per day.(c) Class D-3: Limited treatment systems for community supplies serving a population from 1,000 to 4,000, or with a rated treatment capacity from 0.5 to 2.0 million gallons of water per day.(d) Class D-4: Limited treatment systems for community supplies serving a population of less than 1,000, or with a rated treatment capacity less than 0.5 million gallons of water per day.(e) Class D-5: Limited treatment systems for noncommunity supplies.(3) Waterworks systems that use as a source surface water or ground water under the direct influence of surface water shall be classified as F systems.Mich. Admin. Code R. 325.11901