Protecting Wisconsin's Groundwater Through Comprehensive Planning
Image of checksLearn more about groundwaterIntegrate groundwater into your planFind data and polices in your areaBrowse for resourcesChecks

 Find data and policies in your area
  Walworth County
  This report provides the most current information and data found, as of May 2007, unless otherwise noted.
  Walworth County groundwater findings reports Walworth County full report Switch to Walworth 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. Walworth County has 16 municipal water systems.  Table showing water systems in Walworth County

GROUNDWATER PROTECTION POLICIES   Table showing water systems in Walworth County

  • 11 of 16 municipal water systems in Walworth County have a wellhead protection plan: Darien, East Troy, Elkhorn, Fontana, Genoa City, Lake Geneva, Town of Lyons, Pell Lake, Sharon, Whitewater and Williams Bay.
  • 8 of 16 municipal water systems in Walworth County have a wellhead protection ordinance: East Troy, Fontana, Genoa City, Lake Geneva, Town of Lyons, Pell Lake, Sharon and Whitewater.
  • Walworth County has adopted an animal waste management ordinance.


  • Over $24 million has been spent on petroleum cleanup in Walworth County from leaking underground storage tanks, which equates to $241 per county resident.
  • 1 municipal water system in Walworth County has spent money to reduce nitrate levels.

GROUNDWATER USE   Water use figure

  • From 1979 to 2005, total water use in Walworth County has increased from about 10.0 million gallons per day to 15.3 million gallons per day.*
  • The increase in total water use over this period is due to increases in all use categories.
  • The proportion of county water use supplied by groundwater has increased from around 89% to about 99% during the period 1979 to 2005.*
  • 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 Walworth County can be seen in the FULL REPORT or accessed through the map link above.


  • 90% of 340 private well samples collected in Walworth 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 Walworth 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
  • 5,128 acres of land in Walworth County are in atrazine prohibition areas. Map showing atrazine prohibition areas in Walworth County
  • 76% of 33 private well samples collected in Walworth County met the health standard for arsenic.


  • There are 172 open-status sites in Walworth County that have contaminated groundwater and/or soil. These sites include52 Leaking Underground Storage Tank (LUST) sites, 62 Environmental Repair (ERP) sites, 56 spill sites and 2 Voluntary Party Liability Exemption (VPLE) sites.  BRRTS map
  • There are 3 concentrated animal feeding operations in Walworth County.
  • There is 1 licensed landfill in Walworth County.
  • There is 1 Superfund site in Walworth County.

return to top

Walworth County full report Walworth 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