Certified labs by state
Missouri
Missouri splits private-well help across two agencies: the Department of Health and Senior Services runs the Private Drinking Water Program and test-kit process, while the Department of Natural Resources publishes certified drinking-water laboratory lists. Missouri also maintains official private-well sampling maps showing county-level results for 10 contaminants from homeowner-submitted samples since 2010. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water))
Checked against official sources on October 4, 2026. Rules and links change; confirm with the office listed before you act.
- Certifies drinking water labs
- Missouri Department of Natural Resources for certified chemical drinking-water laboratories; Missouri Department of Health and Senior Services for certified microbiological drinking-water laboratories. ([dnr.mo.gov](https://dnr.mo.gov/water/business-industry-other-entities/certified-laboratories))
- Official certified lab list
- Official page →
- Free or low-cost testing
- No statewide free private-well water testing program was found on current Missouri official pages; DHSS says testing is voluntary and offered as a public health service, and some counties may provide additional testing services. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/missouri-private-drinking-water-testing-requirements?utm_source=openai))
Official resources in Missouri
Overview page for Missouri's private well program, annual testing advice, and links to kits, maps, and related contaminant information.
Explains Missouri State Public Health Laboratory private-well bacteria and chemical testing, annual recommended tests, and how to get a kit through your local public health agency.
County-level maps for wells and 10 contaminants based on private samples submitted to the state laboratory since 2010.
Portal to Missouri's certified chemical and microbiological drinking-water laboratory lists.
University of Missouri Extension guidance on private-well management and when broader testing such as VOCs or pesticides may be warranted.
Key facts for Missouri
- Missouri DHSS recommends testing private well water at least annually and whenever the well is serviced or water changes in look, smell, or taste. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water))
- DHSS specifically says to test once each year for total coliform bacteria, E. coli, and nitrates. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/well-water-test-kit-information-and-services?utm_source=openai))
- Missouri's private-well program is DHSS Bureau of Environmental Epidemiology; it provides technical assistance on testing, interpretation, and treatment. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water))
- Missouri's official private-well sampling maps show county well counts plus 10 contaminant maps using samples submitted since 2010. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/private-well-sampling-maps))
- DHSS says common Missouri groundwater contaminants include nitrates and heavy metals; its metals panel includes arsenic, lead, manganese, and uranium. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/well-water-test-kit-information-and-services))
- DHSS says radionuclides in Missouri groundwater commonly include uranium, radium, and radon; private-well radionuclide testing should be considered every three years or more often if detected. ([health.mo.gov](https://health.mo.gov/sites/health/files/media/pdf/2026/03/rads-in-mo-ada.pdf))
What to do next
- Start with DHSS's annual minimum panel: total coliform, E. coli, and nitrate, then add metals or radionuclides if your area has mining history or map results concern you. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/well-water-test-kit-information-and-services?utm_source=openai))
- Use the Missouri Private Well Sampling Maps to check your county before ordering extra tests such as arsenic, uranium, or other contaminants. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/private-well-sampling-maps))
- Get your sample kit through your local public health agency; some counties also provide added well-testing services or may send a representative. ([health.mo.gov](https://health.mo.gov/prevention/environmental-factors/private-drinking-water/well-water-test-kit-information-and-services))
Helpful guides
- How to choose a state-certified drinking water lab
- What to test your private well water for (and how often)
- How to collect a well water sample without ruining the test
- How to read a water test report: MCLs, units and flags