Certified labs by state
Montana
Montana DEQ says private wells are common statewide, but DEQ does not regulate private-well water quality, so owners are responsible for testing and maintenance. Montana State University Extension’s Well Educated program gives county-specific testing guidance because groundwater concerns vary across Montana, and its statewide summaries identify arsenic and uranium as major contributors to risk. Source: https://deq.mt.gov/water/resources ; https://waterquality.montana.edu/well-ed/results-summaries/index.html ([deq.mt.gov](https://deq.mt.gov/water/resources))
Checked against official sources on October 4, 2026. Rules and links change; confirm with the office listed before you act.
- Certifies drinking water labs
- Montana Department of Public Health and Human Services (DPHHS) Laboratory Certification Program
- Free or low-cost testing
- Official free program found: Montana DPHHS Choose Safe Places offers free, confidential private-well testing for prospective or licensed childcare facilities; no broader statewide free household-well testing program was identified in the official pages reviewed. Sources: https://dphhs.mt.gov/publichealth/Epidemiology/TEPH/APPLETREE/CSP ; https://deq.mt.gov/water/resources ([dphhs.mt.gov](https://dphhs.mt.gov/publichealth/Epidemiology/TEPH/APPLETREE/CSP))
Official resources in Montana
County-by-county map showing what to test for in different parts of Montana based on groundwater data. ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html))
Resident-friendly list of Montana labs and which parameters each is certified to analyze. ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/testing/certifiedlabs.html))
Key facts for Montana
- DEQ says it does not oversee or regulate water quality from private wells; owners are responsible for ensuring their drinking water is safe. Source: https://deq.mt.gov/water/resources ([deq.mt.gov](https://deq.mt.gov/water/resources))
- DEQ says private supplies should be tested annually for nitrate and bacterial contamination; it also suggests spring wet-weather coliform testing. Source: https://deq.mt.gov/water/resources ([deq.mt.gov](https://deq.mt.gov/water/resources))
- MSU’s minimum annual private-well panel is bacteria (coliform plus E. coli) and nitrate plus nitrite as nitrogen. Source: https://waterquality.montana.edu/well-ed/testing/choiceguide.html ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/testing/choiceguide.html))
- MSU’s statewide county guidance lists exceedances for arsenic, fluoride, nitrate+nitrite, selenium, and uranium; lead and copper are usually plumbing-related. Source: https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html))
- MSU says arsenic is primarily from natural sources, while nitrate in groundwater is associated with human sources. Source: https://waterquality.montana.edu/well-ed/results-summaries/index.html ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/results-summaries/index.html))
- DPHHS reports that in southwestern Montana, nearly 41% of sampled wells had at least one radioactive substance above an EPA standard or screening level, especially in Boulder batholith rocks. Source: https://dphhs.mt.gov/publichealth/Epidemiology/TEPH/ehresources/safedrinkingwater ([dphhs.mt.gov](https://dphhs.mt.gov/publichealth/Epidemiology/TEPH/ehresources/safedrinkingwater))
What to do next
- Start with MSU’s county guidance map to choose a Montana-specific test package, then confirm sample bottles and hold times with a certified lab before collecting water. Sources: https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html ; https://waterquality.montana.edu/well-ed/testing/certifiedlabs.html ([waterquality.montana.edu](https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html))
- At minimum, test every year for bacteria and nitrate/nitrite; add arsenic, uranium, fluoride, selenium, or other local contaminants if your county guidance or nearby geology suggests risk. Sources: https://deq.mt.gov/water/resources ; https://waterquality.montana.edu/well-ed/testing/choiceguide.html ; https://waterquality.montana.edu/well-ed/testing/statewide_countyguidance.html ([deq.mt.gov](https://deq.mt.gov/water/resources))
- Retest after flooding, well repairs, or noticeable taste/odor/color changes, and be especially proactive if the water is used by infants or during pregnancy. Source: https://deq.mt.gov/water/resources ([deq.mt.gov](https://deq.mt.gov/water/resources))
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