A boil water order is issued by the Missouri Department of Natural Resources to public water systems when a threat to the public health exists, or is likely to exist, that boiling the water will remedy. E. coli bacteria or high turbidity in drinking water are the cause of most boil orders issued in Missouri. The public water system is required to notify consumers as soon as possible, and by the most effective methods, that they need to boil their drinking water.
Not to be confused with a boil water order, a public water system may issue a boil water advisory as a precautionary measure when there is concern that a problem with drinking water may exist, but it has not yet been confirmed. These are most commonly issued for major water main breaks or other low-pressure events. They may also be issued while waiting for sample results collected for bacteriological analysis.
Steps to Take
Affected consumers should boil their drinking water for three to five minutes, which should kill any microbes present. For more information, review the department's Boil Water Orders and Boil Water Advisories - PUB2001 fact sheet. For guidance on providing potable water during catastrophic events, review Guidance on Selection and Use of Portable Water Treatment Units for Providing Potable Water as a Last Resort under Emergency Conditions.