Colorado has revoked waivers from as many as 72 public drinking-water systems and is now requiring chlorine treatment of most public supplies as part of the response to a salmonella-poisoning epidemic that ravaged Alamosa last year.

The city signed off on an agreement with the state Wednesday laying out water testing, monitoring and chlorination requirements in the wake of the March salmonella outbreak. The consent order requires the city to chlorinate its water at a level between one and two milligrams per liter at the point of entry.