Assembly Bill 129 mandates that all public and private schools in Wisconsin develop a comprehensive drinking water management plan within 15 months of the bill's enactment. This plan must include the identification of locations for filtered bottle-filling stations and faucets, ensure at least one filtered bottle-filling station for every 100 occupants, and establish a schedule for regular water sampling and testing for contaminants such as lead, PFOA, and PFOS. If testing reveals lead levels between one and five parts per billion, schools must check filters and retest the water. If levels exceed five parts per billion or if PFOA or PFOS are detected above state or federal standards, schools must shut off the affected water outlet, notify parents, and develop a remediation plan.

By August 1, 2027, schools are required to install the specified filtered water stations and faucets, and they are prohibited from installing traditional drinking fountains that do not meet these new standards. The Department of Public Instruction (DPI) is tasked with assisting schools in compliance, including providing templates for the management plans, training on testing protocols, and potentially awarding grants to help cover costs, although no specific funding is allocated for these grants in the bill.