Possible unsafe mineral found in water

Thumbnail for strontium in water
Thumbnail for strontium in water

GREEN BAY - It's called strontium and it's a mineral that can be found in your drinking water.

According to the state's Department of Health Services, the mineral occurs naturally in the environment and this type of strontium is not radioactive.

A recent study by the University of Wisconsin-Green Bay took 115 samples from municipal and private wells.

"As you come closer to Brown County and Outagamie County, people have their wells pulling water out of rock layers that are further down in the earth," said UW-Green Bay Geoscience Professor John Luczaj.

The older rock holds minerals like strontium and if water is present, it can dissolve the mineral.

"If you notice where you have the yellow, and especially the red and orange dots on here, those are samples from wells where you have something like four milligrams per liter or higher, dissolved strontium. There are a number of wells throughout the region that actually exceed this short-term health advisory," Luczaj said.

The Environmental Protection Agency says the Lifetime Health Advisory Limit for strontium in your drinking water shouldn't be more than four milligrams per liter.

The preliminary findings from the UW-Green Bay study found 73 of its samples contained higher levels of strontium than the EPA's recommendation.

“Somebody who maybe tests their water, and it comes out higher than four milligrams per liter, should not immediately assume that suddenly they're going to have negative health effects," said Roy Irving, a toxicologist with the Wisconsin Department of Health Services.

Unlike well water, the Green Bay Water Utility gets its water from Lake Michigan. Although the water goes through a filtration process, the company still tests for strontium and other material within the drinking water each year.

"What we have to do is monitor our water for the presence of elements, or contaminants, and measure them against what the EPA has determined as what's called a maximum contaminate level (mcl). We are finding strontium, our sampling last year with this UCMR3 rule indicated, .12/.13, levels. So we are four percent of that lifetime health advisory," said Nancy Quirk, general manager of Green Bay Water Utility

Based on the UW Green Bay study, the DNR is looking into the strontium results that were found.

"The DNR will be working with the Department of Health (and) the Wisconsin Geological Survey to determine if we need to set the groundwater standard for strontium," said Kyle Burton, groundwater project manager with the DNR.

The DNR recommends private well owners to sample their wells for bacteria, strontium, and other minerals that may be in the drinking water.