DES MOINES, Iowa (AP) — Cities in Iowa, including Council Bluffs, have won a legal victory in a lawsuit against the Environmental Protection Agency over wastewater treatment rules. In a ruling that documents say could save cities across the U.S. $150 billion, the 8th U.S. Circuit Court of Appeals struck down two EPA rules. The decision filed Monday affects the way cities mix water to dilute the bacteria levels near recreational areas and how cities treat wastewater during heavy rains.

A three-member panel of the court says unanimously in nullifying the two rules that the EPA exceeded its legal authority and didn’t follow proper rulemaking. The cities lost their first challenge to EPA rules in 2010 but refiled it in 2011. Among the cities that would have been affected are Council Bluffs, Davenport, Des Moines, Ottumwa, and Waterloo.