Walker signed the bill on Wednesday.
The Department of Natural Resources imposed sweeping restrictions on phosphorus discharge in 2010. Municipalities and manufacturers contend they'll have to spend millions of dollars on upgrades to meet the limits, driving up rates.
The Republican bill calls for asking federal officials to approve a statewide exemption from the rules. That would allow dischargers to ask the state for up to four five-year exemptions. Each exemption would carry a progressively tougher discharge limit.