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Molybdenum In Groundwater

Molybdenum (Mo) is a metallic element that is naturally present, usually at low levels, in the earth's crust. Small amounts of molybdenum are necessary for human health and are obtained from common foods in the diet such as leafy vegetables, legumes, grains and organ meats. Naturally-occurring levels of molybdenum in groundwater are low; the U.S. Geologic Survey found an average of 1 microgram of molybdenum per liter of water (μg/L) nationwide. Higher levels have been found in soil or groundwater and are typically connected to spills or historic waste disposal practices. 

Molybdenum In Southeast Wisconsin

Molybdenum concentrations above the state health advisory level were found in monitoring wells and private water supply wells in southeast Wisconsin. A two-year DNR study was unable to determine the origin of the elevated levels of molybdenum.

Who Should Test

The DNR, along with DHS recommend that private well users in municipalities with molybdenum results at 90 μg/L or greater test their well water for molybdenum at least once. This testing can be done along with recommended annual testing for bacteria and nitrates. Most well owners do not need to include molybdenum during annual well testing. Learn more at the Wisconsin Department of Health Services (DHS) website.

The following municipalities had at least two molybdenum sample results over 90 (μg/L):

Beloit, Belvidere, Bristol, Caledonia, Dover, Franklin, Mount Pleasant, Muskego, Norway, Pacific, Pleasant Prairie, Raymond, Somers, St. Lawrence, Waukesha, Wilson and Yorkville.

Testing your well water

Contact a certified laboratory that can test your water for a specific contaminant.

How To Properly Collect A Water Sample

The laboratory you work through will provide you with a water sampling kit. The video below is demonstration showing basic methods for properly collecting a water sample to yield accurate results.

Health Information

Exposure to high levels of molybdenum can impact health. Learn more at DHS molybdenum in drinking water

Water Treatment Devices

Distillation and Reverse Osmosis can be effective at reducing molybdenum concentration in water.

A licensed pump installer, well driller or similar water industry professional should be hired to correctly install an appropriate treatment device.

Contacts

Molybdenum in southeast WisconsinJesse Jensen
414-263-8774
Drinking water, wells and well testingGreg Roanhouse
262-884-2356
Caledonia Groundwater Molybdenum InvestigationMark Peters
608-516-0820
Molybdenum health issuesDept. of Health Services (DHS)
608-264-9829
Molybdenum treatmentGlen Schlueter
Dept. of Safety & Professional Services (DSPS)
608-267-1401

Additional resources