LEHI — City water superintendent Lee Barnes hopes to give Traverse Mountain residents an "all clear" by Monday following work to flush elevated levels of the metal thallium from culinary water lines.

The city issued a drinking water alert March 8 after test results showed unsafe levels of the metal in a well that serves the Traverse Mountain area. Other water sources have been in use since then to supply the area while crews have been working to flush water lines and bring the supply network back into compliance.

Barnes said Wednesday that all but one segment being tested was now in compliance. He expects test results Thursday will show all segments are ready to be put back online.

The city is considering blending water from the well that had elevated levels of thallium with water from other sources to maintain compliance levels.

The Environmental Protection Agency has found that elevated levels of thallium can cause gastrointestinal irritation and peripheral neuropathy, a nerve function disorder. EPA and state standards for acceptable thallium levels in culinary water is 2 parts per billion for long-term exposure and 7 parts per billion for exposures of one to 10 days.

Tests from the Oak Hollow Well tested in the 2 to 6 parts per billion range as recently as March 2, Barnes said.

The Drinking Water division of the state Department of Environmental Quality must give its approval before the water system goes back online. Barnes said he will send Traverse Mountain residents a letter, hopefully Monday, with word the system is safe and operational.

Steve Fidel Twitter: SteveFidel