Private Well Water Testing

Where can I get water testing kits?

Water quality testing kits are available in the County Annex, in Choteau, across from the Sanitarian’s office. You can also call the Department of Public Health and Human Services’ Environmental Laboratory and request they send you the materials necessary. The Environmental Laboratory can be reached at (800) 821-7284.

The bottles and forms required vary depending on what test needs to be performed.

What tests are available?

  • Nitrate + Nitrite only: This test requires the green form and one 250-mL bottle. High nitrate levels can cause severe health issues in pregnant women and children. The EPA’s maximum contaminant level for Nitrates is 10 mg/L. Nitrates are also used by the State of Montana to monitor the impact of human waste to water sources. Having high nitrates may be the result of excessive fertilizer use, proximity to a septic system, or natural deposits. Special filters exist than can filter nitrates from your water. Elevated nitrate levels may prevent a landowner from installing a septic system.
  • Bacteriological (Coliform): This test requires the yellow form and one 100-mL bottle. Do not remove the small tablet or powder in the 100-mL bottle, as it helps preserve the sample. Not all coliform bacteria are harmful to human health, but they can be indicative of troublesome bacteria. These bacteria are always present in the digestive tracts of animals, so their presence may indicate fecal contamination in your well. The most infamous coliform bacteria is E. coli.
  • Basic Screen: This test requires the blue form, a 250-mL bottle, and a 100 mL bottle. This test includes both the Nitrate + Nitrite test and the Bacteriological test [See above for test explanations]. It also measures specific conductivity, which is a measure of how well your water can conduct an electrical charge. This is used by the State of Montana to determine whether or not a water source is legally considered “high quality”. Generally it can be used as an indicator of dissolved solids in a water source. There are a variety of human and naturally occurring sources.
  • Metals Screen: This test requires the blue form and one 250-mL bottle. It tests for Lead, Arsenic, Calcium, Sodium, Copper, Magnesium, Uranium, and Hardness. The effects of these metals range from staining pipes and laundry to causing severe neurological issues.
  • Anion Screen: This test requires the blue form and one 250-mL bottle. It tests for Sufate, Alkalinity, Fluoride, Chloride, and pH. Abnormal levels in any of these also cause a variety of effects, such as rapidly wearing out water treatment equipment or affecting the taste of water.

There are also a variety of testing kits that requires the Environmental Laboratory to send you supplies, such as the Volatile Organic Compound screen, the Pesticide screen, and the Herbicide screen. Contact the Environmental Laboratory for a full list of available tests.


Collection instructions and pricing vary. Refer to the Environmental Laboratory for additional information. If you have any questions or would like a sample kit set up for you, please contact the Sanitarian at (406) 466-2150 or

 What if my well is contaminated?

If your well water is unsafe to drink, you should use bottled water until you decontaminate your well and retest it. Decontaminating your well depends on what contaminate you’re trying to remove. For a bacteriological contamination, follow these instructions on disinfecting your well. Additional information can be found via the MSU Extension Office’s Water Quality Program.