Assembly Bill 1129 establishes a new water infrastructure assistance program specifically for 3rd class and 4th class cities, villages, and towns, as well as sanitation districts serving these areas. The program aims to finance the construction of necessary upgrades to water infrastructure systems to ensure compliance with federal water quality standards. The Department of Natural Resources is tasked with administering the program and is granted a continuing appropriation of $10,000,000 to operate the assistance program and provide payments.

The bill outlines the process for cities, villages, towns, and sanitation districts to apply for assistance, including the establishment of eligibility criteria and project priorities by the Department. Upon approval of applications, the department may enter into agreements to cover up to 50% of the estimated reasonable costs of approved projects, with specific terms and conditions. The bill also includes provisions for the department to review and approve project plans and specifications.