The City of Three Forks announced Thursday that it has removed a water treatment plant from operation due to elevated levels of arsenic.

According to Water Superintendent Randy Johnston, the treatment plant for Well 2, which supplies drinking water for the entire city, failed and had to be shut down.

As a result of the failure, arsenic levels in city tap water were up to six times higher than the acceptable level of .01 parts per billion.

Johnston confirms that he and other public works employees were not aware of the high levels of arsenic in the city's water until a call came in on February 14 from MarCom Lab Services in Butte.

A member of the MarCom staff was running a test on a Three Forks tap water sample that her 7th grade niece collected at the middle school and submitted for a science project back in January.

That staff member conducting the test looked over the results and decided to contact Johnston and the public works team in Three Forks.

"I was shocked," Johnston said about receiving the call from the lab over samples from the student's science project.

Johnston says he immediately switched over from the Madison-fed well to the in-town wells, which then made the arsenic levels drop back down to normal.

The last test conducted by the city on its tap water was done in August of 2018.

Here is what Johnston had to say about what may have ultimately led to officials being unaware of the increased arsenic levels:

"Where the ball was dropped was when we first opened that plant we were doing monthly samples for arsenic, but the Department of Environmental quality switched us to quarterly, then they said you're doing really well and switched us to annually."

The city announced in a statement that the plant will continue to be closed while it adds new media in order to lower the level of arsenic. As a result of these findings, quarterly monitoring will now be in place for the duration of the treatment plant's operation.

According to Johnston, there are approximately 900 water hookups, serving nearly 2,000 residents of Three Forks. He says "the whole town," including schools, was receiving tap water with elevated arsenic levels until the switch to the in-town wells was made.

The City of Three Forks released the following statement to residents, Thursday:

This is not an immediate risk. If it had been, you would have been notified immediately. However, some people who drink water containing arsenic in excess of the MCL over many years may experience skin damage or problems with their circulatory system and may have an increased risk of getting cancer.

Johnston says of the student's findings, "I'm glad she caught it," and hopes more frequent testing will help the city's water quality moving forward.