Clean drinking water is essential for our health, whether it comes from a public water system or a private well. Having pristine lakes, rivers, and streams also supports our health. The Missouri Environmental Public Health Tracking (EPHT) Program shares data on water quality in Missouri.
Drinking Water
How is Drinking Water Tested?
Public water systems monitor public drinking water for contaminants, like chemicals and bacteria, on a regular basis. The Missouri Department of Natural Resources oversees public water systems to make sure our public water is safe to drink. The amount of a chemical in the water is compared to the highest amount allowed by the U. S. Environmental Protection Agency (also called the Maximum Contaminant Level or MCL).
Private well water testing is the responsibility of homeowners. If you have a private well, DHSS recommends you test it at least once each year; anytime the well is serviced; or if you notice a change in the look, smell or taste of your water. You can learn more about private well testing from the DHSS Private Drinking Water Program.
Drinking Water Data
Search this query to find:
Annual mean concentrations of contaminants in public water systems
Quarterly mean concentrations of contaminants in public water systems
Annual maximum concentrations of contaminants in public water systems
Number of public water systems with chemical concentrations above or below the MCL, and population served by those water systems
Percent of public water systems with chemical concentrations above or below the MCL, and percent of population served by those water systems
Other Data Sources
Other data sources provide additional data on public and private drinking water.
Harmful Algal Blooms in Lakes, Ponds and Streams
Algal blooms can sometimes be found in lakes, ponds, and slow-moving streams in Missouri, especially during warmer weather. These blooms are caused by the growth of tiny organisms called algae or cyanobacteria (also known as blue-green algae) in the water. Not all blooms are harmful, but some can produce toxins (poisons) that can make you and your animals sick soon after being in the water. Drinking water or eating fish or shellfish from water with an algal bloom might also make you or your animals sick.
Private Drinking Water Maps
The DHSS Private Drinking Water Program recommends you test your well annually/ after it is serviced; or anytime there is a change in look, taste or smell of your private drinking water.
Fish Advisory
Fish consumption advisories in Missouri.
Algal Bloom Reporting Form
If you see an algal bloom, please report it.
The National Environmental Public Health Tracking Program
Missouri Environmental Public Health Tracking (EPHT) is a program within the Missouri Department of Health and Senior Services and funded by the Centers for Disease Control and Prevention. EPHT is part of a network of people and information systems which delivers a core set of health, exposure, and hazards data, information summaries and tools to enable analysis, visualization and reporting of insights drawn from data. Those insights are intended to help data drive actions and improve community health.