Coliform bacteria contamination in Bigfork’s drinking water supply was discovered last month, prompting the Bigfork County Water and Sewer District to alert water users.

The district did not issue a boil-water order, but has advised water users that people with severely compromised immune systems, infants and some elderly residents may be at increased risk.

A letter was sent along with monthly water bills to about 1,200 users. Owners of apartment or other multi-unit buildings were instructed to notify tenants.

The district has started using its emergency chlorination system. Users may detect the taste and/or smell of chlorine until the situation is resolved.

“Operators will also be flushing fire hydrants to get the chlorine throughout the distribution system,” District Manager Julie Spencer said in the advisory.

During routine monitoring for drinking water contaminants, the district took 11 samples in January to test for coliform bacteria. Seven of the samples showed the presence of the bacteria.

The standard is that no more than one sample per month may show bacteria.

“This is not an emergency,” Spencer stressed in the letter to water users.

Whenever the district detects coliform bacteria in any sample, follow-up testing is done to see if other bacteria of greater concern, such as fecal coliform or E. coli, are present.

“We did not find any of these [other] bacteria in our subsequent testing,” she said.

The district is working closely with the Montana Department of Environmental Quality to resolve the problem.

“We anticipate resolving the problem within 30 days,” Spencer said.

For more information, contact Spencer at 837-4566.