Lehi officials warned Traverse Mountain residents Thursday that their water had higher-than-acceptable levels of the metallic element thallium.
Lee Barnes, the city’s water superintendent, said the Oak Hollow well, which had served Traverse Ridge, was shut down in 2011, and the city is flushing the lines to remove the metallic element.
Ken Bousfield, director of the state Division of Drinking Water, said the problem dates to 2010, when thallium was first detected at levels above the federal standard of 2 parts per billion.
The reported levels were between 2.1 and 2.6 parts per billion, Barnes said.
Bousfield said the well was taken off line last year, and water was pumped from other, uncontaminated wells. But he said recent tests still showed thallium levels as high as 3 parts per billion.
Bousfield said thallium was likely coming from residue in the water pipes left from the Oak Hollow water that was being dissolved in the new water. The state recommended the city aggressively flush the water lines.
According to the U.S. Environmental Protection Agency, people who drink thallium-contaminated water over a course of years could experience hair loss, kidney and liver problems.
Barnes said the city recommended people with health problems drink bottled water until the flushing is complete.
Bousfield said the thallium was naturally occurring, with the water picking up the element as it passes through the ground to the aquifer.
Barnes said the city is considering a plan to combine the Oak Hollow water with other water sources, thus diluting the thallium to safe levels.