Important information about your drinking water

  • Published
MALMSTROM AIR FORCE BASE, Mont. --  The Malmstrom AFB water system recently violated the Environmental Protection Agency (EPA) Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1DBPR) drinking water standards. Disinfection byproducts such as Haloacetic Acids (HAA5) and Trihalomethanes (TTHM) are a result of adding chlorine disinfectant to drinking water.

The EPA requires that quarterly samples be taken to analyze for HAA5 and TTHM. The EPA requires reporting when a running average of four consecutive quarters is more than 60 micrograms per liter (ug/l) for HAA5. Malmstrom results over the last four quarters exceeded the HAA5 EPA Maximum Contaminant Level (MCL) with an average value of 61 ug/l. One microgram per liter is approximately equal to one part per billion.

As our consumers, you have the right to know what happened and what is being done.

What does this mean?

This is not an emergency. If it had been an emergency, you would have been notified immediately.

· The term 'Total Haloacetic Acids' (HAA5) refers to the sum of the concentrations of dichloroacetic acid, trichloroacetic acid, monochloroacetic acid, monobromoacetic acid and dibromoacetic acid in a water sample. HAA5s can be present in chlorinated drinking water as a disinfectant byproduct formed when the chlorine reacts with natural organic matter and/or bromide ions in raw water supplies.
· Some people who drink water containing HAA5 in excess of the MCL over many years may have an increased risk of getting cancer.

What should I do?

You do not need to use an alternative water source. You do not need to boil your water or take any other corrective actions. There is no specific population at risk. However, if you have specific health concerns, please consult your physician.

What happened?

Bioenvironmental Engineering routinely monitors the drinking water for contaminants. A running four-quarter average of the results is compared to the EPA- established MCLs. Throughout 2009, technicians collected the required four samples for HAA5. These results caused the average for the year to exceed the established MCL, which prompted this notice.

This is the fifth consecutive four-quarter average MCL violation requiring a public notification. The notices for previous violations were distributed to the base population on 6 Feb 2009, 1 May 2009, 3 Aug 2009, and 16 Oct 2009.

What was done?

When Malmstrom first received indication of high HAA5 last year, we immediately began aggressively flushing the water lines. A new waterline project to improve water quality by increasing circulation was completed this summer. Malmstrom also implemented rigorous sampling protocols and convened an expert stakeholder group to help us analyze data, evaluate test methods, and to suggest solutions.

What is next?

Malmstrom is working with the EPA, Montana Department of Environmental Quality, the USAF Environmental, Safety and Occupation Health (ESOH) Service Center, the City of Great Falls and others to identify the causes of disinfection byproducts and develop solutions to reduce them while still maintaining adequate levels of disinfectant.

We implemented a comprehensive sampling program recommended by the expert stakeholder group to further characterize the water constituents. Analysts are reviewing the data and will use it to develop alternatives for reducing DBPs. The base may see a reduction in the amount of disinfection byproducts once the data has been studied and a proposed solution developed and implemented.

release date of this notice: 25 January 2010