Protecting Wisconsin's Groundwater Through Comprehensive Planning
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  Rock County
  This report provides the most current information and data found, as of May 2007, unless otherwise noted.
  Rock County groundwater findings reports Rock County full report Switch to Rock 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. Rock County has 9 municipal water systems.  Table showing water systems in Rock County

GROUNDWATER PROTECTION POLICIES   Table showing water systems in Rock County

  • 6 of 9 municipal water systems in Rock County have a wellhead protection plan: Clinton, Evansville, Footville, Janesville, Milton, and Orfordville.
  • 2 of 9 municipal water systems in Rock County have a wellhead protection ordinance: Evansville and Janesville.
  • Rock County has adopted an animal waste management ordinance.


  • Over $24 million has been spent on petroleum cleanup in Rock County from leaking underground storage tanks, which equates to $156 per county resident.
  • 4 municipal water systems in Rock County have spent money to reduce nitrate levels.

GROUNDWATER USE    Water use figure

  • From 1979 to 2005, total water use in Rock County has increased from about 27.2 million gallons per day to about 45.4 million gallons per day.*
  • The increase in total water use over this period is due to increases in domestic and irrigation uses.
  • The proportion of county water use supplied by groundwater increased from about 92% to over 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 Rock County can be seen in the FULL REPORT or accessed through the map link above.


  • 75% of 482 private well samples collected in Rock County from 1990-2006 met the health-based drinking water limit for nitrate-nitrogen.   Nitrate map
  • A 2002 study estimated that 62% of private drinking water wells in the region of Wisconsin that includes Rock 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
  • 18,941 acres of land in Rock County are in atrazine prohibition areas. Map showing atrazine prohibition areas in Rock County
  • 100% of 18 private well samples collected in Rock County met the health standard for arsenic.


  • There are 85 open-status sites in Rock County that have contaminated groundwater and/or soil. These sites include 34 Leaking Underground Storage Tank (LUST) sites, 47 Environmental Repair (ERP) sites, 3 spill sites and 1 Voluntary Party Liability Exemption (VPLE) site.  BRRTS map
  • There are 2 concentrated animal feeding operations in Rock County.
  • There are 3 licensed landfills in Rock County.
  • There are 2 Superfund sites in Rock County.

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Rock County full report Rock 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