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
  Iowa County
  The Find Section provides the most current information and data found, as of May 2007, unless otherwise noted.
   
  Iowa County groundwater findings reports Iowa County full report Switch to Iowa County executive summary
 

SOURCES OF DRINKING WATER

Wisconsin enjoys a generally clean and abundant groundwater resource.A2 This resource is present because of the state’s geologic history and climate; this resource is protected through strong state and federal regulations, and the cooperative efforts of water systems, trade associations, individual operators, planning commissions, and state and federal science agencies.

Drinking water in Wisconsin is provided by either public water systems or private wells. A public water system is defined as a system that provides public water for human consumption, if such a system has at least 15 service connections or regularly serves an average of at least 25 individuals daily at least 60 days out of the year. Wisconsin has nearly 11,500 public water systems which meet the daily water needs of about 4 million people.A1 The Wisconsin Department of Natural Resources (WDNR)A3 oversees these public systems, and additional information can be found online.  

Public water systems that are owned by a community are called municipal water systems.A4 Iowa County has 13 municipal water systems.  Table showing public water systems in Iowa County

In addition to the public water systems, about 850,000 private wells provide drinking water to Wisconsin's population. Unlike public water systems, protection and maintenance of a private well is largely the responsibility of homeowners. Information on how to build and protect your private water supply can be found on the WDNR web site.A5 The USGS is finalizing the "Summary of Water Use in Wisconsin for 2005." When released, this summary will show the percentage of the Iowa County population whose drinking water comes from private wells versus municipal systems.

return to top

 

GROUNDWATER PROTECTION POLICIES

WELLHEAD PROTECTION PLANS AND ORDINANCES   Table showing water systems in Iowa County

  • 4 of 13 municipal water systems in Iowa County have a wellhead protection plan: Arena, Barneveld, Dodgeville and Hollandale.B1
  • 2 of 13 municipal water systems in Iowa County have a wellhead protection ordinance: Arena and Hollandale.B1
For recommendations of groundwater protection policies and some outstanding examples of innovative groundwater protection policies adopted by other communities see Groundwater Protection Policies.
 

Wellhead protection plans are developed to achieve groundwater pollution prevention measures within public water supply wellhead areas. In some areas of the state, sophisticated groundwater flow modeling techniques were used to delineate source water areas for municipal wells. A wellhead protection plan uses public involvement to delineate the wellhead protection area, inventory potential groundwater contamination sources, and manage the wellhead protection area. All new municipal wells are required to have a wellhead protection plan. A wellhead protection ordinance is a zoning ordinance that implements the wellhead protection plan by controlling land uses in the wellhead protection area.B2

Of those municipal water systems that have wellhead protection (WHP) plans, some have a WHP plan for all of their wells, while others only have a plan for one or some of their wells. Similarly, of those municipal water systems that have WHP ordinances, some ordinances apply to all of their wells and others just one or some of their wells.

ANIMAL WASTE MANAGEMENT ORDINANCES

  • Iowa County has adopted an animal waste management ordinance.B3

Most Wisconsin counties have adopted an animal waste management ordinance that applies to all unincorporated areas of the county (areas outside of city and village boundaries). While the purposes of such ordinances vary among counties, a key purpose is often to protect the groundwater and surface water resources. This is accomplished by regulations such as:

  • Permitting of animal waste storage facilities;
  • Permitting of new and expanding feedlots;
  • Nutrient management;
  • Prohibiting:
    • Overflow of manure storage structures;
    • Unconfined manure stacking or piling within areas adjacent to stream banks, lakeshores, and in drainage channels;
    • Direct runoff from feedlots or stored manure to waters of the state;
    • Unlimited livestock access to waters of the state where high concentrations of animals prevent adequate sod cover maintenance.

More information is available from the WDATCP.

ADDITIONAL GROUNDWATER PROTECTION POLICIES

Your county may have additional policies in place for groundwater protection. A good way to find out is to check with the county conservationist and local zoning administrators.

return to top

 

MONEY SPENT ON CLEANUP

PETROLEUM ENVIRONMENTAL CLEANUP FUND AWARD

  • Over $4 million have been spent in Iowa County on petroleum cleanup from leaking underground storage tanks, which equates to $183 per county resident.C2

The Petroleum Environmental Cleanup Fund Award (PECFA) program was created in response to enactment of federal regulations requiring release prevention from underground storage tanks and cleanup of existing contamination from those tanks. PECFA is a reimbursement program returning a portion of incurred remedial cleanup costs to owners of eligible petroleum product systems, including home heating oil systems.C1

As of May 31, 2007, $4,344,816 have been reimbursed by the PECFA fund to clean up 32 petroleum-contaminated sites in Iowa County. This equates to $183 per county resident, which is less than the statewide average of $264 per resident.C2

NITRATE REMOVAL SYSTEMS

  • No municipal water systems in Iowa County have spent money to reduce nitrate levels.

As of 2005, over 20 municipal water systems in Wisconsin have spent over $24 million reducing nitrate concentrations in municipal water systems.C3

return to top

 

GROUNDWATER USE

Water use in Iowa County
Water use in Iowa County
CLICK FOR FULL SIZE
  • From 1979 to 2005, total water use in Iowa County has increased from about 7.2 million gallons per day to about 11 million gallons per day.*
  • The increase in total water use is due primarily to an increase in irrigation.
  • The proportion of county water use supplied by groundwater has been between 99% about 97% during the period 1979 to 2005.*

As part of the National Water-Use Information Program, the USGS stores water-use data in standardized format for different categories of water use. In 1978, the USGS entered into a cooperative program with the WDNR to inventory water use in Wisconsin. Since that time, five reports summarizing water use have been published (Lawrence and Ellefson, 1982D2; Ellefson and others, 1987D3; Ellefson and others, 1993D4; Ellefson and others, 1997D5; Ellefson and others, 2002D6; Buchwald and others, 2008D7).

Water use in Wisconsin in these summary reports is reported in the following categories: domestic, livestock, aquaculture, industrial, commercial, public use and losses, thermoelectric or mining. References describing the methods for collecting data and estimating water use are provided in the summary reports.

* 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. D1

return to top

 

SUSCEPTIBILITY OF GROUNDWATER TO CONTAMINANTS

Susceptibility of groundwater to pollutants in Iowa County
 
Susceptibility of groundwater
to pollutants
in Iowa County
CLICK FOR FULL SIZE
 

In Wisconsin, 70% of residents and 97% of communities rely on groundwater as their drinking water source. Wisconsin has abundant quantities of high-quality groundwater, but once groundwater is contaminated, it's expensive and often not technically possible to clean. Because of these factors, we need to be careful to protect our groundwater from contamination. Our activities on the land can contaminate groundwater - most contaminants originate on the land surface and filter down to the groundwater. In some cases however, groundwater can become contaminated from natural causes such as radioactivity due to the presence of radium in certain types of rocks.

READ MORE ABOUT SUSCEPTIBILITY

return to top

 

GROUNDWATER QUALITY

NITRATE

Nitrate-nitrogen concentrations in Iowa County
 
Nitrate-nitrogen concentrations in Iowa County
CLICK FOR FULL SIZE
 
  • 88% of 465 private well samples collected in Iowa County from 1990-2006 met the health-based drinking water limit for nitrate-nitrogen.

Of the 465 samples that have been collected in the county, 196 samples (42%) contained between 2 and 10 mg/L (milligrams per liter, or parts per million) nitrate-nitrogen, and serve as indicators that land use has likely affected groundwater quality. An additional 55 samples (12%) exceeded the health-based drinking water limit of 10 mg/L nitrate-nitrogen.F1

As shown in the map on the right, the samples where nitrate-nitrogen levels were elevated are located throughout the county.F2

Introduction and Sources of Nitrate

In 2006, the WDNR and the Wisconsin Department of Agriculture, Trade and Consumer Protection (WDATCP) reported that nitrate-nitrogen (NO3-N) is the most widespread groundwater contaminant in Wisconsin, and that the nitrate problem is increasing both in extent and severity.F3 In Wisconsin's groundwater, 80% of nitrate inputs originate from manure spreading, agricultural fertilizers, and legume cropping systems.F4 On-site wastewater systems (septic systems) can also be a significant nitrate source in densely populated areas, areas where fractured bedrock is near the surface, or areas with coarse-textured soils.F5

Concentrations of nitrate-nitrogen in private water supplies frequently exceed the drinking water limit (federal and state Maximum Contaminant Level, or MCL) of 10 mg/L. In 2005, the WDNR combined data from three statewide groundwater databases and found that 11.6% of 48,818 private wells exceeded the nitrate limit.F3

Percent of drinking water samples with nitrate levels over the health standardLand use affects nitrate concentrations in groundwater. As shown in the figure on the right, an analysis of over 35,000 Wisconsin drinking water samples found that drinking water from private wells was three times more likely to be unsafe to drink due to high nitrate in agricultural areas than in forested areas. High nitrate levels were also more common in sandy areas where the soil is more permeable.F6 Groundwater with high nitrate from agricultural lands is more likely to contain pesticides than groundwater with low nitrate levels.F7

Health effects of nitrate
READ MORE

Ecosystem effects of nitrate
READ MORE

Solutions
READ MORE

Planning
READ MORE

PESTICIDES

  • A 2002 study estimated that 43% of private drinking water wells in the region of Wisconsin that includes Iowa 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.F24
  • 9,416 acres of land in Iowa County are in atrazine prohibition areas.F25

Definition and Use

A pesticide is any substance used to kill, control or repel pests or to prevent the damage that pests may cause.F26 Included in the broad term “pesticide” are herbicides to control weeds, insecticides to control insects, and fungicides to control fungi and molds. Pesticides are used by businesses and homeowners as well as by farmers, but figures for the amounts and specific types of pesticides used are not generally available on a county-by-county basis.

A 2005 report indicates that approximately 13 million pounds of pesticides are applied to major agricultural crops in Wisconsin each year, including over 8.5 million pounds of herbicides, 315,000 pounds of insecticides, one million pounds of fungicides, and 3 million pounds of other chemicals (this last category applied mainly to potatoes).F27 The report also shows that herbicides are used on 100% of carrots for processing, 99% of potatoes, 98% of cucumbers for processing, 98% of soybeans, 97% of field corn, 89% of snap beans for processing, 87% of sweet corn, and 84% of green peas for processing. Insecticides are used on 97% of potatoes, 96% of carrots, and 88% of apples. Fungicides are used on 99% of potatoes, 88% of carrots, and 89% of apples.

Top five crops by acreage grown in Iowa County in 2005-06
and average pesticide application per crop in Wisconsin.

Commodity
Acres
Pounds of pesticides
applied per acre

(statewide average)
Corn for grain
66,000
2
Soybeans
30,100
1
Corn for silage
9,900
2
Oats
8,400
0.1
Wheat all
1,600
**
** no available data
Source: USDA QuickstatsF45 and USDA Statistics by StateF46

The number of pounds of pesticide applied per acre in Wisconsin varies greatly by crop, from 28 pounds/acre for apples to less than one pound/acre for oats and barley (see table below).F27

Total pounds of pesticides applied to
major crops in Wisconsin, 2004-2005.

Crop
Acres
Total pounds
of pesticides applied
Pounds of pesticides
applied per acre
Apples
5,800
163,300
28
Potatoes
68,000
950,000
14
Tart cherries
1,800
14,700
8
Carrots for processing
4,200
29,400
7
Snap beans
76,000
251,600
3
Sweet corn
88,400
198,000
2
Field corn
3,800,000
6,503,000
2
Green peas for processing
30,200
33,500
1
Soybeans
1,610,000
1,770,000
1
Cucumbers for processing
4,600
3,800
1
Cabbage, fresh
4,400
2,700
1
Barley
55,000
5,000
<1
Oats
400,000
25,000
<1

Atrazine Prohibition Areas

As of 2006, the WDATCP has prohibited the use of the popular corn herbicide atrazine on 102 designated atrazine prohibition areas in Wisconsin, covering about 1.2 million acres.F25 The map below shows the 9,416 acres of land located in atrazine prohibition areas in Iowa County.

Atrazine prohibition areas in Iowa County
 

Atrazine prohibition areas
in Iowa County
CLICK FOR FULL SIZE

 
   
Percentage of private wells with detectable herbicides or herbicide metabolites in Wisconsin thumbnail  
Percentage of private wells with herbicides or herbicide metabolites
CLICK FOR FULL SIZE
 

Environmental fate of pesticides

Once a pesticide is applied, it ideally will harm only the target pest and then break down through natural processes into harmless substances.

However, the actual fate of pesticides in the environment may include evaporation into the air; runoff into surface water; plant uptake; breakdown by sunlight, soil microorganisms or chemical reactions; attachment to soil particles; leaching into groundwater; or remaining on the plant surface and removal at harvest.

The WDATCP conducted a private well water study from 2000-2001, looking for some of the most commonly used herbicides in Wisconsin.F29 From that study, the statewide estimate of the proportion of private drinking water wells that contained a detectable level of a herbicide or herbicide metabolite (breakdown product) was 37.7%. The map at the right shows the estimated percentage of wells containing herbicide or herbicide metabolites by region. The study did not look at less commonly used herbicides or any insecticides or fungicides. WDATCP is doing a similar study in 2007 that includes analysis for a greater number of pesticides.
READ MORE

Health effects of pesticides
READ MORE

Planning
READ MORE

ARSENIC

  • 95% of 20 private well samples collected in Iowa County met the health standard for arsenic.F43

Of the 20 water samples analyzed for arsenic in Iowa County, 9 samples (45%) have detectable arsenic and 1 sample (5%) are greater than the recently reduced drinking water limit of 10 µg/L (micrograms per liter, or parts per billion).F44

Most private wells in the county have unknown arsenic levels.

Introduction

Arsenic is an element that occurs naturally in some of Wisconsin’s aquifers and may contaminate well water drawn from those aquifers. It is a particular problem in parts of the Fox River valley of northeastern Wisconsin. However, arsenic has been detected in wells in every county in Wisconsin, and arsenic concentrations greater than the drinking water limit of 10 µg/L have been documented in 51 of Wisconsin’s 72 counties.F3

Health effects of arsenic
READ MORE

Release of arsenic into groundwater
READ MORE

Planning
READ MORE

For further information on arsenic, please visit the WDNR Arsenic in Drinking Water and Groundwater web site.

OTHER GROUNDWATER CONTAMINANTS

Information on volatile organic compounds, pharmaceuticals and personal care products, and chloride.
READ MORE

return to top

 

POTENTIAL SOURCES OF CONTAMINANTS

Since groundwater gets into the ground at the land surface, it makes sense that what happens on the land surface can have impact on groundwater. A great many land use activities have the potential to impact the natural quality of groundwater, as shown in the table below. A landfill may leach contaminants into the ground that end up contaminating groundwater. Gasoline may leak from an underground storage tank into groundwater. Fertilizers and pesticides can seep into the ground from application on farm fields, golf courses or lawns. Intentional dumping or accidental spills of paint, used motor oil, or other chemicals on the ground can result in contaminated groundwater. The list could go on and on.G1 The rest of this section provides county-specific information about potential sources of groundwater contaminants.

ACTIVITIES THAT MAY CONTAMINATE GROUNDWATERG1

Table showing activities that may contaminate groundwater

CONTAMINATED GROUNDWATER AND/OR SOIL

  • There are 22 open-status sites in Iowa County that have contaminated groundwater and/or soil. These sites are composed of 12 Leaking Underground Storage Tank (LUST) sites and 10 Environmental Repair (ERP) sites.G2
Map of BRRTS sites in Iowa County
BRRTS sites
in Iowa County
CLICK FOR FULL SIZE

Properties that were or are contaminated with hazardous substances can be found using the WDNR's Bureau for Remediation and Redevelopment Tracking System (BRRTS). The figure on the right shows the BRRTS map of contaminated sites in Iowa County. Royal blue diamonds on the map indicate open leaking underground storage tank (LUST) sites which have contaminated soil and/or groundwater with petroleum, which includes toxic and cancer-causing substances. However, given time, petroleum contamination naturally breaks down in the environment. Turquoise diamonds on the map indicate open environmental repair (ERP) sites which are sites other than LUSTs that have contaminated soil and/or groundwater. Examples include industrial spills or dumping, buried containers of hazardous substances, and closed landfills that have caused contamination. More information for the sites on the figure is available online.

About the BRRTS
READ MORE

What is a Hazardous Substance?
READ MORE

How to use BRRTS information in comprehensive planning
READ MORE

For more information, please see Environmental Contamination – The Basics, WDNR publication PUB-RR-674 July, 2004.

CONCENTRATED ANIMAL FEEDING OPERATION (CAFO):

  • There are no concentrated animal feeding operations in Iowa County.G3

By definition, CAFOs have greater than 1000 animal units. CAFOs are required under their Wisconsin Pollutant Discharge Elimination System (WPDES) permits to practice proper manure management and ensure that adverse impacts to water quality do not occur. Permit applicants must submit detailed information about the operation, a manure management plan, plans and specifications for all manure storage facilities, and a completed environmental analysis questionnaire. Once a WPDES CAFO permit is issued, operators must comply with the terms of the permit by following approved construction specifications and manure spreading plans, conducting a monitoring and inspection program, and providing annual reports.

Other potential groundwater contaminants from agriculture include fertilizers and pesticides. Large amounts of nitrogen fertilizers are used when fields are planted continuously with corn, and they can leach into groundwater as nitrate.

For more information, please visit the WDNR CAFO web site.

LICENSED LANDFILLS

  • There are no licensed landfills in Iowa County.G4

The county may have additional facilities listed in the Registry of Waste Disposal Sites, available from the WDNR, that includes active, inactive, and abandoned sites where solid or hazardous wastes were known, or were likely, to have been disposed. The inclusion of a site on the Registry does not mean that environmental contamination has occurred, is occurring, or will occur in the future. The Registry is intended to serve as a general informational source for the public, and State and local officials, as to the location of waste disposal sites in Wisconsin.

About Wisconsin's Solid Waste Management Program
READ MORE

SUPERFUND SITES

  • There are no Superfund sites in Iowa County.G6

What is Superfund?
READ MORE

return to top

 

NEXT STEPS

Now that you’ve inventoried groundwater data and analyzed it, what’s next? How do you use this information to lead to on-the-ground actions?

Now comes the key part of the planning process, where it’s important to involve as many community members as possible to develop and implement a plan of action to protect groundwater. The following sections of this web site are intended to help your community move forward together to protect groundwater.

return to top

Iowa County full report Iowa County full report
   

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

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