More Colorado drinking-water systems using chlorine |

More Colorado drinking-water systems using chlorine

DENVER (AP) – More drinking-water systems across Colorado are treating their water with chlorine following the deadly salmonella outbreak in Alamosa last year.

State health officials announced Wednesday that animal waste that seeped into an underground storage tank likely caused the outbreak. The report said that the bacteria may not have grown had Alamosa used chlorine to disinfect its water supply.

The city had a waiver exempting it from a state requirement to use the chemical since 1974.

Following the outbreak, the state sped up its review of waivers and has revoked at least 72 of them, including Alamosa’s. Other are being reviewed.

The Alamosa outbreak was the nation’s worst waterborne-disease outbreak since 2004. One person died and as many as 1,300 were sickened.