1998 Annual Compliance Report of Missouri Drinking Water Systems

The 1998 Annual Compliance Report of Missouri Drinking Water Systems, published by the Missouri Department of Natural Resources (DNR), is now available. The report, compiled by the Public Drinking Water Program, describes the extent of violations by Missouri public water systems during 1998.


The 1998 Annual Compliance Report

The 1998 Annual Compliance Report covers Missouri’s 2,714 public water systems. On a population basis, 96 percent of the 4.7 million Missourians served by community public drinking water systems received drinking water that met all maximum contaminant level (MCL) standards in 1998. A maximum contaminant level is the highest level of a specified contaminant that will still be protective of public health.

The Department of Natural Resources' director expressed his confidence in public drinking water systems in the state. The department expects a lot from our water systems and require testing for as many as 90 different regulated chemicals and microbiological contaminants during the year. A system is to be applauded for performing all required testing and meeting all maximum contaminant level standards.

Many water systems perform testing beyond that required by the state. A public water system, by definition, provides water for human consumption through pipes, or similar means, to at least 15 service connections or serves an average of 25 people for at least 60 days each year. Water testing at systems serving fewer people than this is facilitated by local and county sanitarians and the Missouri Department of Health, rather than DNR.

There are three basic types of public water systems. The first is a community system, where people live and consume the water on a daily basis. A community water system could serve the residents of a large city, a rural water district, or a small mobile home park or subdivision. The second is a non-transient, non-community system, such as a school or factory where people drink the water on an on-going basis. The third is a transient, non-community system, such as a restaurant, resort, or campground that would not be a regular source of drinking water for most of its pass through consumers.

Most violations were either a maximum contaminant level violation, where the acceptable level of a specific contaminant is exceeded, or a monitoring violation when the required testing was not performed in the specified time frame, or at all. Generally those violations were for total coliform bacteria, which all public water systems in the state must test for every month they dispense water to the public.

A number of systems missed collecting samples for one or two months; few systems missed sampling for three or more months. Only 83, or 3 percent of systems were listed on the U.S. Environmental Protection Agency’s (EPA) list of Significant Noncompliers in 1998.

For all violations, public water systems are required to notify their consumers. The method of notification varies by the violation and system type. Systems must then report back to DNR how the public notice was performed. DNR works closely with public water systems to help them remain in or return to compliance in a timely manner.

The following table summarizes the violation statistics from the 1998 Annual Compliance Report.

Contaminant Group/Rule Type of Violation Number of Violations Number of Systems with Violations
Organic Chemicals Monitoring 252 12
Organic Chemicals MCL * 4 2
Trihalomethanes Monitoring 0 0
Trihalomethanes MCL * 0 0
Inorganic Contaminants Monitoring 121 11
Inorganic Contaminants MCL * 1 1
Nitrate Monitoring 92 92
Nitrate MCL * 0 0
Radionuclides Monitoring 49 49
Radionuclides MCL * 6 6
Total Coliform Rule Monitoring 1140 665
Total Coliform Rule MCL * 551 377
Surface Water Treatment Monitoring 0 0
Surface Water Treatment Treatment 7 6
Lead and Copper Monitoring 38 38
Lead and Copper Treatment 0 0
* MCL = Maximum Contaminant Level

You can receive a copy of the 1998 Annual Compliance Report of Missouri Public Drinking Water Systems by accessing    The 1998 Annual Compliance Report or by writing to DNR’s Water Protection Program, Drinking Water Branch, P.O. Box 176, Jefferson City, MO 65102, or calling
800-361-4827 or 573-751-5331.