Residents will start receiving notices this week in their water bill about elevated levels of haloacetic acids, or HAA5, in the city’s drinking water.

There is no risk to public health, according to city officials. The notification is required by the U.S. Environmental Protection Agency.

The slightly elevated levels were found in samples from the third quarter of 2018, which was July through September.

Increased runoff in Missouri caused slight elevation of haloacetic acids in city water; no public health risk

City Manager Greg Doyon notified City Commissioners of the issue during Tuesday night’s meeting and Jim Rearden, public works director, and Wayne Lovelis, the water plant manager, provided additional information.

The HAA5 levels have been an issue for the city and other water systems around Montana this year, Lovelis told The Electric earlier this year.

HAA5 is a byproduct of organic material interacting with the chlorine used to treat drinking water.

City officials have said that wildfire activity could be the major source of organic material making its way into rivers and earlier this year, Lovelis said the heavy snowpack and early thaw caused a higher than normal amount of organic material in the river.

The city had slightly elevated levels in the spring and notified residents through their water bills.

Rearden told commissioners that August typically has more runoff, which requires more chlorine to treat drinking water.

Rearden and Lovelis said they’re testing a different chlorine injection point at the water treatment plant and once construction at the plant is completed, less chlorine will be required for water treatment. Lovelis said they should have results on Wednesday on whether moving the chlorine injection point can impact the interactions with organic material.

The turbidity, or suspended material in the water, has been high in the Missouri River in recent months, so there’s more organic material to react with the chlorine that’s used for treating drinking water.

If you have specific health questions, Lovelis recommends contacting your health care professional.

The city checks for other contaminants on a monthly basis and when there is a public health hazard, the city immediately notifies the health department, Montana Department of Environmental Quality and the public.