Chippewa County Well Water Monitoring Project

Created by: Grant Moser, Jennifer Dierauer, Abby Johnson, and Kevin Masarik
Center for Watershed Science and Education in partnership with Chippewa County
Last modified: March 30, 2021 . Contact us for questions


Chippewa County has been a national leader in gathering information on well water quality. Major well water sampling efforts have been conducted in 1985, 2007, and 2016. Beginning in 2019 Chippewa County has been working with the University of Wisconsin - Stevens Point and University of Wisconsin - Madison, Division of Extension to evaluate water quality on a more routine basis. While the number of wells is less than previous years, the goal is to test these wells annually in order to assess changes in groundwater quality within Chippewa County.

  • 2007 - 800 well owners participated
  • 2016 - 744 well owners participated
  • 2019 - 155 well owners participated
  • 2020 - 164 well owners participated

The information collected through these efforts will be used to analyze where and what factors may be contributing to any changes in groundwater quality observed over time. The well network is intended to be representative of Chippewa County (i.e. accounting for the wide variety of geology, soils, land-use, and well construction found throughout the area).

Using the Map

Map Type

Individual Wells: When individual wells are selected, this map view allows you to see the water quality test results for each well that was sampled. The well points are approximate locations in order to protect the privacy of participants. Clicking on the points will provide the water quality result for whichever test is selected.

Municipality: When the municipality view is selected, the map displays the average concentration for each of the water quality tests conducted. Clicking on the municipality will provide summary statistics by town.


This drop down menu allows you to see results from different years. Additional data will be made available as the project progresses.


This drop down menu switches allows you to view the different analytes or various attributes associated with the wells

LEARN about tests

Samples are analyzed for nitrate-nitrogen, chloride, alkalinity, total hardness, pH, and conductivity. Nitrate and chloride are useful for understanding the degree to which groundwater has been affected by human activities. Click on the 'LEARN about tests' tab To learn more about the specific tests and what they tell us about groundwater.

EXPLORE project data

Data can further be explored for trends over time in individual wells, municipal summaries, or county-wide. Click on the 'EXPLORE project data' tab to investigate data in more detail.

What is Nitrate

This test measures the amount of nitrate-nitrogen in your well. Nitrate is a form of nitrogen, commonly found in agricultural and lawn fertilizer, that easily dissolves in water. It is also formed when waste materials such as manure or septic effluent decompose. The natural level of nitrate in Wisconsin's groundwater is less than 1 mg/L. Levels greater than this suggest groundwater has been impacted by various land-use practices.

Why Test for Nitrate

Nitrate is an important test for determining the safety of well water for drinking. Nitrate is a test that allows us to understand the influence of human activities on well water quality. Because it moves can come from a variety of sources and moves easily through soil, it serves as a useful indicator of certain land-use activities. An annual nitrate test is useful for better understanding whether water quality is getting better, worse, or staying the same with respect to certain land-uses (see Sources).

Interpreting Nitrate-Nitrogen Concentrations

Health Effects of Nitrate in Drinking Water

Ways to reduce nitrate in your drinking water

One way to reduce nitrate is to install a water treatment device approved for removal of nitrate; testing is the only way to make sure these devices are properly functioning

Point-of-use devices treat enough water for drinking and cooking needs
  • Reverse Osmosis
  • Distillation
Point-of-entry systems treat all water distributed throughout the house
  • Anion Exchange
Additionally, you may want to investigate the potential that drilling a new well or well reconstruction may provide water with safe nitrate levels

Sources of Nitrate

  • Agricultural Fertilizers
  • Manure and other biosolids
  • Septic Systems
  • Lawn Fertilizers

Strategies to reduce nitrate in groundwater

  • Applying fertilizer at the right rate, time, source, place will maximize profitability and minimize excessive losses of nitrogen to groundwater; additional practices may be needed to improve water quality in areas with susceptible soils and geology
  • You may not need as much nitrogen fertilizer as you think, conduct your own on-farm rate trials to develop customized fertilizer response curves for your farm
  • Utilize conservation incentive programs to take marginal land or underperforming parts of fields out of production
  • Diversify cropping systems to include less nitrogen intensive crops in the rotation
  • Explore and experiment with the use of cover crops, perennial cropping systems, or managed grazing to reduce nitrate losses to groundwater

What is Chloride

In most areas of Wisconsin, chloride concentrations are naturally low (usually less than 15 mg/L). Higher concentrations may serve as an indication that the groundwater supplied to your well has been impacted by various human activities.

Why Test for Chloride

Chloride is a test that allows us to understand the influence of human activities on well water quality. Measuring chloride concentrations in your well water will allow us to better understand whether well water quality is getting better, worse, or staying the same with respect to certain land-uses (see Sources).

Interpreting Chloride Concentrations

Chloride is not toxic at typical concentrations found in groundwater. Unusually high concentrations of chloride (greater than 150 mg/L) are often associated with road salt and may be related to nearby parking lots or road culverts where meltwater from winter deicing activities often accumulates. Water with concentrations greater than 250 mg/L are likely to contain elevated sodium and are sometimes associated with a salty taste; water is also more likely to be corrosive to certain metals.

Sources of Chloride

  • Agricultural Fertilizers (chloride is a companion ion of potash fertilizers)
  • Manure and other biosolids
  • Septic Systems
  • Road Salt

What is Alkalinity

Alkalinity is a measure of water's ability to neutralize acids. Alkalinity is associated with carbonate minerals and is commonly found in areas where groundwater is stored or transported in carbonate aquifers which occur in parts of Chippewa County.

Why Test for Alkalinity

Because alkalinity is related to the rocks and soils that water flows through on its way to a well, we would expect alkalinity concentrations to be fairly stable from year to year. Any changes observed in alkalinity concentrations may help us better understand the influence of climate variability on well water quality on an individual well, or make sense of broader water quality results from Chippewa County. Particularly in wells that are uninfluenced by human activity, Alkalinity concentrations may help us better understand which wells are accessing younger water that may be more vulnerable or prone to contamination.

Interpreting Alkalinity Concentrations

There are no health concerns associated with having alkalinity in water. Alkalinity should be roughly 75-100% of the total hardness value in an unsoftened sample. Water with low levels of alkalinity (less than 150 mg/L) is more likely to be corrosive. High alkalinity water (greater than 200 mg/L), may contribute to scale formation. If total hardness is half or less than the alkalinity result, it likely indicates that your water has passed through a water softener. If alkalinity is significantly less than total hardness, it be related to elevated levels of chloride or nitrate in your water sample.

What is Total Hardness

The hardness test measures the amount of calcium and mangnesium in water. Calcium and magnesium are essential nutrients, which generally come from naturally sources of these elements in rock and soils. The amount present in drinking water is generally not a significant source of these nutrients compared with a health diet.

Why Test for Total Hardness

Because total hardness is related to the rocks and soils that water flows through on its way to a well, we would expect total hardness concentrations to be fairly stable from year to year. Any changes observed in total hardness concentrations may help us better understand the influence of climate variability on well water quality on an individual well. Because hardness concentrations have been shown to increase when nitrate and/or chloride increase, the total hardness test is a good complement to other tests.

Interpreting Total Hardness Concentrations

There are no health concerns associated with having total hardness in your water, however too much or too little hardness can be associated with various aesthetic issues that can impact plumbing and other functions.

Hard Water:

Water with a total hardness value greater than 200 mgL is considered hard water. Hard water can cause lime buildup (scaling) in pipes and water heaters. Elements responsible for water hardness can also react with soap decreasing its cleaning ability, can cause buildup of soap scum, and/or graying of white laundry over time. Some people that use hard water for showering may notice problems with dry skin.

If you are experiencing problems with hard water: Consider softening water using a water softener. Water softeners remove calcium and magnesium and replace those elements with a different cation (usually sodium). Many people choose not to soften the cold-water tap used for drinking/cooking and the outdoor faucet used for yard watering.

Soft Water:

Water with a total hardness concentration less than 150 mg/L is considered soft. Water with too little hardness is often associated with corrosive water, which can be problematic for households with copper plumbing or other metal components of a plumbing system. Please note: Total Hardness values less than 50 would be rare for Chippewa County, if your water reported less than 50 mg/L of Total Hardness it likely represents softened or partially softened water.

If you are experiencing problems with soft water or corrosion of household plumbing: You may want to consider a water treatment device (called a neutralizer) designed to make water less corrosive. Newer homes with plastic plumbing generally don't need to be as concerned with corrosive water with respect to the plumbing.


Water with total hardness between 150-200 mg/L is generally an ideal range of water hardness because there are enough ions to protect against corrosion, but not too many that they contribute to scale formation. While it is a personal preference, households with hardness in this range generally don't require additional treatment.

Note: the water softening industry measures hardness in grains per gallon. 1 grain per gallon = 17.1 mg/L as CaCO3

Sources of Total Hardness

Primarily dissolved carbonate minerals from soil and rock materials. When carbonate minerals dissolve, they increase the amount of calcium and magnesium ions in water.

What is pH

The pH test measures the concentration of hydrogen ions in a solution. The concentration of hydrogen determines if a solution is acidic or basic. The lower the pH, the more corrosive water will be.

Why Test for pH

The pH of groundwater in Wisconsin in typically between 6.5 and 8.5. Lower or higher values can occasionally occur in parts of the state because of certain geologic characteristics. While there are not health concerns associated with pH levels typical of Wisconsin groundwater, corrosive water (pH less than 7) is more likely to contain elevated levels of copper and/or lead if those materials occur in the plumbing system.

Low pH values are most often caused by a lack of carbonate minerals. Low total hardness and alkalinity are often correlated with low or acidic pH values.

What is Conductivity

Conductivity measures the amount of dissolved substances (or ions) in water; but does not give an indication of which minerals are present. Changes in conductivity over time may indicate changes in overall water quality.

Why test for Conductivity

There is no health standard associated conductivity. A normal conductivity value measured in umhos/cm is roughly twice the total hardness (measured as CaCO3) in unsoftened water samples. If conductivity is significantly greater than twice the hardness, it may indicate the presence of other human-influenced or naturally occurring ions such as chloride, nitrate, or sulfate. Because conductivity is relatively easy and cost effective to measrue, understanding variations in conductivity may help in designing cost effective monitoring strategies for homeowners to monitor their well water continuously through sensors rather than annual test.

Investigate Water Quality by Individual Well

One of the major goals of the project is to understand variability in well water quality over time. By sampling the same wells annually, we can better understand whether water quaility is different from one year to the next or relatively similar. If water quality is different, we can make assessments of whether those differences constitute an increasing or decreasing trend.

Well Water Project IDs have been assigned specifically for this project. If you are a participant and know your well's Project ID, you can select or enter from the drop-down menu. Otherwise if you are interested in learning about a particular point on the map, simply click on the point and enter that Project ID into the drop down menu. In order to maintain anonymity, Project IDs have only been shared with project participants for their individual well.

Investigate Water Quality by Municipality

Well water quality can be aggregated and displayed by municipality. Select a parameter from the drop down menu to display the summary statistics as box plots by town. Hover over the box plot to see values for mean (blue diamond), median, minimum, maximum values.

The drop down menu can also be used to view data for a particular year of the project.

Investigate County-wide Summary Statistics

Summary statistics can be generated for all wells tested as part of the annual trend monitoring. Select an analyte to see summary statistics for all wells tested by year. Hover over the box plot to see values for mean (blue diamond), median, minimum, maximum values.