Marshfield & Calumet Drinking Water Sampling Results

Fond du Lac County UW-Extension recently completed a drinking water sampling program in partnership with the Towns of Calumet & Marshfield.

 63 households sampled wells.  At the Marshfield Town Hall on October 20, each participant received an individualized packet of sampling results which were explained in the program. Here is what we learned about the drinking water:

21% (13) of sampled wells had coliform bacteria present. Coliform bacteria can occur for a number of reasons including poor well maintenance, cracked casing, rodents or insects. No e. Coli, which indicates the presence of human or animal waste, was found in any wells.

8% (5) of sampled wells had nitrate levels over the safe drinking water standard.  Nitrates occur naturally, but at these levels it means that wells are being impacted by fertilizers, manure, septic systems, and other land use activities. Nitrates are typically found in agricultural areas, and they can remain in the soil and in the aquifer for many decades. No one recent event or change to land use can be the source for high readings now.

Only one sampled well had arsenic levels over the health standard. Arsenic is a naturally occurring element found in Wisconsin’s groundwater aquifers.  It is released from soil and rock into the groundwater and drawn into wells. Wells in which arsenic was detected should be monitored closely in the coming years.  Arsenic is a known carcinogen and is a serious health concern.

92% (33) of wells sampled contained no components of triazine herbicides. This is good news in an agricultural area.

Past data from UW-Extension sampling programs show that about 27% of Town of Calumet wells sampled and 13% of Marshfield wells sampled have been bacteria positive. Past data also shows that 6% of wells sampled in both townships have measured nitrate levels over the EPA health standard.

Water quality can change quickly in a short time. It is recommended that people drinking well water sample it at least once per year. If you would like to sample your home well water or if your township would like to host a well water sampling program, contact Diana Hammer Tscheschlok at UW-Extension: 920/748-7565 or


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