Important information about your drinking water

  • Published
  • 341st Missile Wing


Public Notification NOV HAA5 20190125.docx

Malmstrom Air Force Base’s water system exceeded the maximum level for Haloacetic Acids. This is not an emergency, as our customer, you have a right to know what happened, what you should do, and what we are doing to reduce the levels from the water that we purchased from the city of Great Falls.

We are required to monitor your drinking water for specific contaminants on a regular basis. The Stage-2 Disinfection Byproducts (DBP) Rule maximum level for Haloacetic Acids (HAA5) is 60 microgram per liter (ug/L). The test results show that our system exceeded the MCL for HAA5 at 61 ug/L. The MCL is a Locational Running Annual Average (LRAA) which is calculated over the last consecutive four quarters. Our current quarterly reading was 41 ug/L well below the standard of 60 ug/L.

HAA5 concentrations were elevated during the 2nd and 3rd quarters of 2018 perhaps due to the smoke of the spring wildfires present in the drinking water. There is a possibility that our LRAA may be affected in the coming quarters, requiring subsequent notices until results are lowered.

What does this mean? What should the customer do?

This is not an emergency. If it had been, you would’ve been notified immediately. However, according to the EPA, “Some people who drink water containing HAA5 in excess of the MCL over many years, may have an increased risk of cancer.” This is based on preliminary animal research and drinking 2 liters of water daily over an average lifespan.

It is not necessary to boil the water or to use an alternate water source. However, if you want to take extra precautions, you can use an activated carbon filter. Please contact your health care professional, if you have specific health concerns.

Steps We Are Taking:

Malmstrom AFB is committed to providing our customers with the highest water quality possible. We are working with the city of Great Falls to identify process changes that may reduce HAA5 concentrations such as water infrastructure upgrades to include a new chemical feed and Ultra Violet system.

Please share this information with all the other people who drink this water, especially those who may not have received this notice directly. For more information, please contact Bioenvironmental Engineering at 406-731-1580.

PWS ID: MT0000515 Date Distributed: 28 January 2019