The bill amends the Safe Drinking Water Act of 1976 by updating definitions and clarifying the responsibilities of the Department of Environment, Great Lakes, and Energy regarding public water supplies. Key insertions include the definitions of "bottled drinking water," "capacity assessment," and "customer site piping," which now specifies that such piping consists only of distribution and storage facilities owned by the customer. The bill also introduces terms like "mobile home" and "seasonal mobile home park," and revises existing definitions to enhance clarity, such as changing "public water supply" to "waterworks systems" and refining the definition of "state drinking water standards."

Additionally, the bill empowers the department to inspect waterworks systems and take necessary actions to ensure compliance with state drinking water standards. It allows for emergency orders to be issued without prior notice if a waterworks system poses an imminent hazard to public health. The bill mandates that suppliers of water or owners of customer site piping in mobile home parks comply with final orders from the department, and it establishes procedures for public hearings if requested. Overall, the amendments aim to strengthen the regulatory framework for ensuring safe drinking water in Michigan.