Editor’s note: This version is updated to correctly identify Flint, Michigan in the last paragraph.

POULSBO — The Poulsbo City Council has approved additional money for the design and construction of a new water treatment plant to reduce manganese levels in its drinking water.

Manganese occurs naturally in the iron-rich soils found in Kitsap County. But there is some evidence that too much manganese in drinking water may be harmful to older adults and to formula-fed infants, according to scientific studies by the U.S. Environmental Protection Agency and others.

The maximum concentration level of manganese in drinking water is 0.05 parts per million, according to the Office of Drinking Water in the state Department of Health Division of Environmental Health. Sample data going back to 1990 on the Office of Drinking Water web site shows the Pugh/Lincoln Well 2 at 2500 N.E. Lincoln Road had slightly exceeded that maximum for more than a quarter century. So, the city has stopped pumping from that well and started planning for a new water treatment plant.

Initially, the city put up $60,000 for its share of an $80,000 pilot study to determine what needed to be done. The remainder came from the Department of Health.

The city then paid Water Engineering Solutions $123,000 to design a new water treatment plant and bid it. In September 2015, the bid “exceeded the engineer’s estimate and was therefore rejected by council,” the Engineering Department reported.

It was at this point that the Water Engineering Solutions engineer in charge of the project unexpectedly died.

The city was able to secure the use of the plans, but they were going to require extensive revisions in order to reduce costs. If the city made those revisions and oversaw the project, the city would be liable for any future problems or litigation.

Therefore, the engineering department and City Attorney Jim Haney recommended — and the City Council approved at its Dec. 21 meeting — a $69,435 contract with Grey and Osborne Engineering to revise the plans and oversee a new round of bidding.

“The city depends on its wells for water,” City Engineer Diane Lenius said. “We’re growing, so we have to get this fixed.”

One expert who asked to remain anonymous said, “Manganese is considered a ‘secondary’ contaminant, along with the likes of iron, silver and chloride. When the level of manganese in the water rises above 0.05 parts per million, drinking water can taste metallic and may stain fixtures. However, it poses no known immediate threat to individuals. ‘Primary’ contaminants such as lead (think Flint, Michigan) and arsenic and mercury, on the other hand, are known to be dangerous to humans.”