MADISON, Wis. — More than two dozen Republican state lawmakers are asking federal lawmakers to loosen Wisconsin’s strict water pollution standards.

A group of 31 state legislators, led by Sen. Howard Marklein, wrote to Wisconsin’s 10-member congressional delegation on Tuesday. They want help changing what they say are “arbitrary” and “unreasonable” phosphorous standards imposed on municipal wastewater treatment facilities under the EPA’s Clean Water Act.

The group says standards the state adopted in 2010 are overly strict.

In February, the EPA gave the state permission to delay enforcement of limits on phosphorous levels. But the Republicans say that won’t solve the problem and want the U.S. lawmakers to set more “reasonable goals.”

Environmentalists have prioritized reducing phosphorous levels in Wisconsin’s waterways because it contributes to algae growth.