Mich. Comp. Laws § 325.1006

Sec. 6. The maximum contaminant levels for inorganic and organic chemicals, microbiological contaminants and turbidity, which are part of the national interim primary drinking water regulations, and which have been promulgated by the United States environmental protection agency under authority of Public Law 93-523 (1974) before this act taking effect, are hereby incorporated by reference and shall have the same force and effect as a rule promulgated pursuant to this act. A standard which is incorporated by reference pursuant to this subsection shall remain effective until a rule is promulgated pursuant to this act which covers the same or similar subject or the standard is rescinded by rule promulgated pursuant to this act.