The Missouri Department of Natural Resources routinely posts a list of drinking water systems that have chronically failed to do required bacteriological testing. The department requires all public water systems to test for bacteria at least once a month to verify these systems are providing safe drinking water to the public. While failing to monitor does not necessarily mean the water is unsafe, routine testing is a crucial part of maintaining a safe water supply.

The group of bacteria monitored is called total coliform bacteria. These are common in the environment and generally not harmful by themselves. They do indicate the water may be contaminated with organisms that can cause disease. Disease symptoms include diarrhea, cramps, nausea, possible jaundice and associated headaches and fatigue.

If a sample tests positive for total coliform bacteria, further testing is then performed for fecal coliform, or E. coli, bacteria which can directly cause gastrointestinal illness. Most samples that test positive for total coliform test negative for fecal coliform or E. coli. The total coliform positive samples that are listed tested negative for fecal coliform or E. coli unless specifically stated otherwise.

Bacteriological testing can be the first step in identifying and correcting a problem. When a public water system has both a record of failure to monitor and a history of maximum contaminant level violations, department staff is concerned about the unknown quality of the drinking water. Failing to monitor can result in ongoing bacteriological problems.

The vast majorities of community and noncommunity public water systems in the state comply with all monitoring requirements and meet all drinking water standards. Chronic violators are the exception rather than the rule. There are approximately 2,800 public drinking water systems in Missouri, and the number of violators listed is usually less than 1% of these.

These systems' owners have been sent multiple violation notices in addition to certified letters informing them that chronic failure to monitor is unacceptable. Department staff members also routinely make on-site inspections and attempt to reach an agreement with the responsible parties to ensure sampling requirements will be met.

The systems listed have at least four major monitoring violations in a 12-month period. The reports below give the most recent bacteriological results and any maximum contaminant level violations in the system's history recent history.  

Counties with systems listed are presented in alphabetical order. Systems are given in alphabetical order within each county. The cities and counties are given as location references only. Counties with a number of systems listed have a large number of public water systems, most of which are in compliance with drinking water regulations.

For more information, contact the department's Public Drinking Water Branch at 800-361-4827 or 573-751-5331