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 customer site piping consists solely of distribution and storage facilities owned by the customer. The bill also introduces new provisions for the department's authority to inspect waterworks systems and respond to complaints about water quality in mobile home parks.

Additionally, the bill enhances the department's powers to issue orders for necessary changes to ensure compliance with state drinking water standards, particularly in cases where public health is at risk. It specifies that if a waterworks system poses an imminent hazard, the department can issue emergency orders without prior notice or hearing. The bill also outlines the process for public hearings related to orders issued by the department, ensuring that suppliers of water or owners of customer site piping have the opportunity to contest orders before they become final. Overall, the amendments aim to strengthen the regulatory framework for ensuring safe drinking water in Michigan.