Crews in Alamosa have started pumping high concentrations of chlorine into Alamosa's municipal water system in an effort to rid it of salmonella bacteria that has sickened nearly 250 people.

Schools are closed because of the outbreak, and National Guard members and volunteers have gone door to door distributing red fliers notifying people not to use tap water for anything but flushing toilets.

Water distribution centers are set up throughout town, but residents are concerned about showers and whether they'll be able to remain in their homes while city officials try to deal with the problem.

Officials have not been able to pinpoint the source of the contamination.

Gov. Bill Ritter on Monday asked for the federal government's assistance.

(Copyright 2008 by The Associated Press. All Rights Reserved.)