Protecting Wisconsin's Groundwater Through Comprehensive Planning
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  Waukesha County
  This report provides the most current information and data found, as of May 2007, unless otherwise noted.
  Waukesha County groundwater findings reports Waukesha County full report Switch to Waukesha County full report


  • Wisconsin has nearly 11,500 public water systems which meet the daily water needs of about 4 million people. Public water systems that are owned by a community are called municipal water systems. Waukesha County has 20 municipal water systems.  Table showing water systems in Waukesha County

GROUNDWATER PROTECTION POLICIES   Table showing water systems in Waukesha County

  • 10 of 20 municipal water systems in Waukesha County have a wellhead protection plan: Brookfield, City of Pewaukee, Delafield, Hartland, Menomonee Falls, Mukwonago, Muskego, Oconomowoc, Pewaukee Village and Sussex.
  • 7 of 20 municipal water systems in Waukesha County have a wellhead protection ordinance: Brookfield, Delafield, Hartland, Menomonee Falls, Muskego, Pewaukee Village and Sussex.
  • Waukesha County has adopted an animal waste management ordinance.


  • Over $70 million has been spent on petroleum cleanup in Waukesha County from leaking underground storage tanks, which equates to $186 per county resident.
  • 1 municipal water system in Waukesha County has spent money to reduce nitrate levels.

GROUNDWATER USE    Water use figure

  • From 1979 to 2005, total water use in Waukesha County has increased from about 28.0 million gallons per day to about 39.7 million gallons per day.*
  • The increase in total water use over this period is due to increases in all use categories except aquaculture through 2000, with a decrease in industrial, irrigation and public use and losses to 2005.
  • The proportion of county water use supplied by groundwater has generally been greater than 99% during the period 1979 to 2000 and decreased in 2005 to 86%.*
  • Water use in Wisconsin is generally estimated for the following categories:
    • Domestic
    • Livestock
    • Aquaculture
    • Irrigation
    • Industrial
    • Commercial
    • Public use and losses
    • Thermoelectric or mining*

* Thermoelectric and mining data are not considered in water-use tables or figures on this web site. Thermoelectric-power water use is the amount of water used in the process of generating thermoelectric power. The predominant use of water is as non-contact cooling water to condense the steam created to turn the turbines and generate electricity.



  • Wisconsin has abundant quantities of high-quality groundwater, but once groundwater is contaminated, it's very expensive and often not technically possible to clean.
  • An evaluation of the susceptibility of groundwater to contamination in Waukesha County can be seen in the FULL REPORT or accessed through the map link above.


  • 97% of 664 private well samples collected in Waukesha County from 1990-2006 met the health-based drinking water limit for nitrate-nitrogen.   Nitrate map
  • A 2002 study estimated that 21% of private drinking water wells in the region of Wisconsin that includes Waukesha County contained a detectable level of an herbicide or herbicide metabolite. Pesticides occur in groundwater more commonly in agricultural regions, but can occur anywhere pesticides are stored or applied.   Statewide pesticide map
  • There are no atrazine prohibition areas in Waukesha County.
  • 90% of 61 private well samples collected in Waukesha County met the health standard for arsenic.


  • There are 427 open-status sites in Waukesha County that have contaminated groundwater and/or soil. These sites include 124 Leaking Underground Storage Tank (LUST) sites, 159 Environmental Repair (ERP) sites, 132 spill sites and 12 Voluntary Party Liability Exemption (VPLE) sites.   BRRTS map
  • There is 1 concentrated animal feeding operation in Waukesha County.
  • There are 2 licensed landfills in Waukesha County.
  • There are 4 Superfund sites in Waukesha County.

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Waukesha County full report Waukesha County full report

For more information about this web site, its contributors, and the data contained herein, click here.

For assistance in comprehensive planning, please contact Lynn Markham, UW-Stevens Point.
For assistance on groundwater, please contact Charles Dunning, USGS.
Page contact: Webmaster, USGS
Page last updated: January 14, 2008