MoDNR staff member collects drinking water sample from a drinking water treatment plant

The Department of Natural Resources is charged with monitoring Missouri public water supplies to make certain they comply with state and federal rules and regulations and provide safe drinking water to all citizens.

Individual water systems are required to submit samples of their water for laboratory testing to verify the water they are serving to the public meets all federal and state standards. How often and where samples are taken varies by system and contaminant. The department's Drinking Water Watch provides online information on the inventory, sample results, compliance activities and the water quality produced by public water supplies in Missouri. Public water systems are required to provide their customers annual reports. 

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

The department also provides guidance and technical assistance to the public water systems.