GROUNDWATER is the water underneath the earth’s surface that flows freely and can be pumped with wells. Groundwater is an essential resource in Wisconsin. It provides drinking water for 70% of Wisconsin residents and 97% of Wisconsin’s inland communities. Groundwater also feeds our lakes, streams, and wetlands. Groundwater is part of the earth’s water cycle, originating from rainfall percolating (moving) through soil. Groundwater discharges (flows) to lakes and streams, and eventually evaporates to begin the water cycle once again. So, you see, our surface water and groundwater is one connected resource.

We retrieve our groundwater from aquifers beneath the surface. Municipal wells retrieve groundwater from confined aquifers deep below the surface. Many private wells receive water from an unconfined aquifer. These areas are closer to the surface and can be more susceptible to contamination. Throughout history, groundwater has been a hidden and often misunderstood resource. However, as populations grow and land uses intensify, threats to groundwater quality and quantity are increasing.


Everything we do on the land affects our water resources. Our actions can affect the QUALITY and QUANTITY of our water for future generations to deal with. Household chemical use and disposal, local industry, landfills, and agricultural practices are potential contributors to water degradation. Potential contaminants include:

  • Coliform Bacteria / E. Coli
  • Pesticides
  • Nitrate
  • Lead
  • PCBs (polychlorinated biphenyls)
  • Solvents, Gasoline, and Fuel Oils
  • Boron
  • Radon


Most health-related contaminants cannot be seen, tasted or smelled.  The only way to determine the safety of your well water supply is to have the water tested.  Water testing should be a regular routine for private well users since water quality can change over time. It is recommended to have a residential well tested annually. Samples are easy to collect. Our office will send your sample to the UWSP Water and Environmental Analysis Lab (WEAL) in Stevens Point for testing. Your sample results and an interpretation guide will be sent to you within 10 working days after your sample is received in the lab. Additional information may be included if your results indicate a problem.


To ensure that the results are reliable, it is recommended that water samples be sent to a state-certified testing laboratory for analysis.

  • Call our office at (715) 421-8440 to speak to our staff or stop in to pick up a sample bottle.
  • Contact the UWSP Water and Environmental Analysis Lab at weal@uwsp.edu or (715) 346-3209 or visit the website for more information.


Groundwater is a local resource. What land-use activities we allow to take place and how carefully those activities are performed will determine groundwater quality in the area around our homes. Water is a shared resource; we all must do our part to help keep our groundwater supplies safe.

The best way to deal with groundwater contamination is to not contaminate it in the first place.

  • Do not pump in or around rivers/ lakes/ streams
  • Minimize use of household chemicals containing hazardous substances
  • Avoid pouring chemicals, oils, solvents, insecticides down household and storm drains
  • Clean and maintain septic systems properly
  • Reduce fertilizer and pesticide application
  • Plant perennial species that can filter groundwater
Sharing is Caring - Click Below to Share
Support Extension