Well Water Testing

Why test my water?

Unlike public drinking water systems that serve many people, private wells are not monitored by public health authorities. When you are a private well owner, you are responsible for monitoring the quality of your drinking water, and ensuring its safety. 

When should I get my water tested and how often?

It is best to sample routinely, even when there are no apparent changes, as some contaminants do not present with any noticeable signs or smells. All private wells should be tested for bacteria and nitrate annually.  In addition, factors related to the age and location of your home warrant consideration of additional tests. The following are recommended for residents of Gallatin County*:

LeadRecommended every 3-5 years if household plumbing installed before mid-1990s, especially if water is corrosive.
CopperRecommended every 3-5 years if household plumbing includes copper and water is corrosive, particularly if your water has a metallic taste and/or you notice blue-green staining.
Other Parameters to ConsiderArsenic, Copper, Fluoride, and Uranium have been found above threshold values in Gallatin and/or 1+ neighboring county.
Specific Local GuidanceThese additional tests are also recommended at least once, and ideally every 3-5 years:
Residents west of the West Gallatin River should test for arsenic, uranium and fluoride.
Residents in the Bridger Range area should test for fluoride.
Residents east of the Bridger Range and in the Trail Creek area should test for selenium.
Residents in any mountainous or foothills location should consider a broader screening for other metals.
*State-wide testing guidance by county is available HERE.

In addition to annual testing, it’s best to test if:

  • you notice a change in your water quality
  • Water users contract an illness which may be waterborne
  • the area around the well head was inundated in a flood or large storm
  • maintenance is done on the well infrastructure
  • a pregnant woman, a woman anticipating pregnancy, or an infant under the age of six months becomes a water user

The best time to test for bacteria is after spring runoff, or if there is any noticeable change in water taste, color, or smell.  However, testing annually at a time that’s convenient for you is most important.

GLWQD strongly encourages the use of a State-Certified Drinking Water Laboratory to run any recommended tests. Bridger Analytical Laboratory is a state-certified lab conveniently located in Gallatin County. A full list of labs certified by the state of Montana to test drinking water is available HERE.

Montana State University Extension Water Quality‘s
Well Educated Program:

The Well Educated Program began in 1989 with the mission of making well testing affordable for private well owners, in addition to gathering water quality data that can aid in the decision-making process for water resource managers.

Testing through the Well Educated program is done by shipping kit materials to a State-Certified lab in Billings, Montana. This program cannot be used for testing associated with a real estate transaction or for other legally required testing.


The cost to you depends on the parameters you choose to test for.

Each kit includes a cost sheet for various parameter packages.  You are encouraged to run tests for ALL parameters that were recommended based on your aesthetic concerns, well location, and other factors. 

If the recommended tests are cost-prohibitive, you can apply to the Gallatin Conservation District’s Cost Share Program.  GCD will now reimburse Gallatin County residents up to 75% of their well testing costs through the Well Educated program only.  Those interested must fill out an application form and agree to share their testing results with local water resource managers so that these data can be used to further our understanding of water quality in the area. To download an application and learn more about CGD’s cost share program, click HERE.


Gallatin Local Water Quality District
(406) 582-3168
215 W. Mendenhall Street, Suite 300
Bozeman, MT

Gallatin Conservation District
(406) 282-4350
120 South 5th Street, Suites B102-B104
Manhattan, MT 59741


Montana State University Extension Water Quality- Well Educated Program
(406) 994-7381

Gallatin Local Water Quality District
(406) 582-3168

See the Water Quality Interpretation Tool for additional assistance interpreting your test results.

Here is a video from Montana State University Water Quality Extension on sampling your well water: