Great Falls, Montana

Great Falls, Montana Great Falls, Montana

What is the Water Quality in Great Falls, Montana?

Compared to other US cities, Great Falls water quality ranks in the middle range for contamination excluding Lead.

Most of their 26 contaminants have cancer-causing attributes.

  • Arsenic is at extremely high levels: 571x health guidelines.
  • Chloroform is at extremely high levels: 84x health guidelines.
  • Haloacetic acids (HAA5) are at extremely high levels: 425x health guidelines.
  • Haloacetic acids (HAA9) are at extremely high levels: 651x health guidelines.
    • HAA5 and HAA9 are byproducts of chlorine treatment, a common method of disinfecting water supplies.

Let’s look closer at what’s in Great Falls water.

What’s in Great Falls water?

Here are the top 5 chemical compounds in your water and what health issues they can potentially cause:

  1. Arsenic – Potential effect: Cancer
  2. Chloroform – Potential effect: Cancer
  3. Haloacetic acids (HAA5) – Potential effect: Cancer
  4. Haloacetic acids (HAA9) – Potential effect: Cancer
  5. Hexavalent Chromium – Potential effect: Cancer

These are five of the 26 contaminants analyzed by the Environmental Working Group (

11 of these contaminants are rated as exceeding EWG Health Guidelines.

Does Great Falls have Lead contamination?

Yes, Great Falls has lead in its water. The most recent Lead samples collected in 2019 showed concentrations up to 11.0 parts per billion (ppb).

The legal limit for lead is 15 parts per billion. Being well-below this level is a good thing.

  • Concentrations between 3.8 ppb and 15 ppb put a formula-fed baby at risk of elevated blood lead levels. Read more about the symptoms of Lead in water.

There is no safe level of lead for humans.

  • The good news is that 99.99% of the lead can be filtered out.

See the What Can You Do? section below to learn how to filter out contaminants.

Where does Great Falls water come from?

Great Falls water comes from the Missouri River – Great Falls watershed.

All 5 assessed water sources in the Missouri River – Great Falls watershed are in Impaired or Unknown condition. These include:

  • Missouri River – Multiple sections
  • Sand Coulee Creek
  • Smith River
  • Sun River

Ideally, a water source would be rated in Good condition.

Learn more from How’s My Waterway

See below for what you can do to improve Great Falls water.

What Can You Do?

Information about water quality in Great Falls can be surprising.

But there are things you can do in your home to clean up your water.

To Remove Lead and Other Contaminants In Your Home:

There is one solution that beats Brita, PUR, and expensive whole house systems.

  • It costs less per gallon.
  • Needs fewer filter changes.
  • And it doesn’t make your water taste weird.

  • Use Berkey filters with activated carbon to filter out at least 86% of contaminants in your drinking water.
    • Berkey filters can also remove up to 99.99% of Lead in Great Falls water.
    • Brita can filter 14 of 26 contaminants and Lead depending on the filter.
    • Note: We may receive a commission if you decide to purchase filters through links on this page.
  • To filter out 24 of the 26 contaminants, consider a reverse osmosis water filtration system for your house.
    • These are more expensive than pitchers to purchase, but are much more effective.
    • They have the benefit of filtering out heavy hitters like:
      • Androstenedione
      • Arsenic
      • Barium
      • Bromodichloromethane – byproduct of the chlorine disinfection process
      • Chloroform
      • Chromium (hexavalent)
      • Fluoride
      • Haloacetic acids (HAA5 and HAA9)
      • Hexachlorocyclopentadiene
      • Molybdenum
      • Nitrate
      • Nitrite
      • Radium
      • Strontium
      • Total trihalomethanes
      • Uranium

In Your Community:

Contact your local government officials and put pressure on them to invest in cleaner waterways and upgraded city water filtration and treatment.

Go to: to find contact information for your local officials.

Water Quality in Other Montana Cities

Montana Water Quality Page

Sign In


Reset Password

Please enter your username or email address, you will receive a link to create a new password via email.