Statewide Guidance by County
Since 2005, the MSU Extension Well Educated program has provided water quality testing assistance to private well owners across Montana. Data from the program provides insights about what parameters (arsenic, nitrate, etc.) well owners may find in their groundwater in different parts of the state. Currently, data from the 2015 to 2019 program years has been currated into our database, which supports the information on this webpage.
Testing Packages and Parameter Glossary: This page contains information on testing packages offered through the Well Educated Program and a glossary of water quality parameters.
Interactive Map
Click on your county in the to map below to view testing recommendations and parameters of concern in your area. Click here for a 3-minute video overviewing how to use this map to learn what health related water quality issues past well testing has found in different counties.
Statewide Parameters of Concern
MCL = Maximum Contaminant Level
All Parameters with Exceedances | MCL | Units |
Arsenic | 0.01 | mg/L |
Fluoride | 4 | mg/L |
Nitrogen, Nitrate+Nitrite as N | 10 | mg/L |
Selenium | 0.05 | mg/L |
Uranium | 0.03 | mg/L |
Lead* | 0.015 | mg/L |
Copper* | 1.3 | mg/L |
*Lead and copper typically come from plumbing fixtures rather than groundwater, however, corrosive groundwater can exacerbate the issue. |