Nitrate Information

What is Nitrate-N?

Nitrogen is an essential part of every living thing.  Nitrate-N is formed when nitrogen combines with oxygen or ozone.  However, nitrate-N easily dissolves in water and does not adhere to soil which allows it to be easily carried into groundwater, making it one of the most common groundwater pollutants in Juneau County and across the state of Wisconsin.


Where does Nitrate-N come from?
Low levels of nitrate-N (below 1 mg/L) can occur naturally in groundwater.  However, elevated levels of nitrate-N are indicative of impacts from human land use.  The WGCC (Wisconsin Groundwater Coordinating Council) report cites work by Dr. Byron Shaw that states approximately 90% of all nitrate-N inputs to groundwater originate from agricultural sources, 9% from septic systems, and 1% from lawns or other sources.  While nitrate-N contamination of drinking water can be found throughout the state, there are certain areas that are more susceptible due to naturally occurring geology and human land uses. 
To learn more about the Nitrate-N in drinking water you can visit the following resources:

What are the health risks associated with elevated Nitrate-N?

Natural nitrate-N levels in central Wisconsin, absent of all pollution sources, are less than 1 parts per million or 1 mg/L. The health-based drinking water standard and maximum contaminant level (mcl) for nitrate-N is 10 parts per million (as nitrate-N) or 10 mg/L. Nitrate-N above the drinking water standard can affect anyone. Small children and infants, women who are pregnant or who are of childbearing age should absolutely not consume water over the drinking water standard of 10 mg/L. No one should consume drinking water long term with nitrate-N over the drinking water Standard of 10 mg/L.
  • Blue Baby Syndrome (methemoglobinemia)Nitrate-N can affect how our blood carries oxygen. Nitrate-N can turn hemoglobin (the protein in blood that carries oxygen) into methemoglobin. High levels can turn skin to a bluish or gray color and cause more serious health effects like weakness, excess heart rate, fatigue, and dizziness. Nitrate-N can affect babies more seriously because their bodies interact with nitrate-N differently.  When nitrate-N levels are high, water should not be given to babies less than 6 months old or used to make infant formula.
  • Birth DefectsHigh levels of nitrate-N in drinking water may cause neural tube defects (a type of birth defect). The neural tube turns into the brain and spine in an unborn baby. Neural tube defects can occur very early in pregnancy.  When nitrate-N levels are high, women who are or may become pregnant should immediately stop using the water for drinking and preparing foods that use a lot of water.
  • Thyroid DiseaseHigh levels of nitrate-N in drinking water may increase the risk of thyroid disease. Nitrate-N can affect how the thyroid functions by blocking the uptake of iodine. The thyroid needs iodine to make hormones. Low levels of thyroid hormone levels can cause fatigue, weight gain, dry skin, hair loss, and goiters (enlarged thyroid).  When nitrate-N levels are high, everyone should avoid long-term use of the water for drinking and preparing foods that use a lot of water.
  • Colon CancerHigh levels of nitrate-N in drinking water may increase the risk of colon cancer. Nitrate-N may enhance the cancer potential of other compounds or may turn into cancer-causing chemicals like the body. Nitrate-N in drinking water has not been shown to increase the risk of other kinds of cancer.  When nitrate-N levels are high, everyone should avoid long-term use of the water for drinking and preparing foods that use a lot of water.
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How do I know if Nitrate-N is elevated in my drinking water?

Since nitrate-N does not smell, taste, or have any color, the only way to know for certain if it is present in your private well is to have it tested by a state certified water laboratory.  Professionals recommend that your water be tested at least annually for nitrate-N and bacteria. 

To search for a state-certified drinking water laboratory please click here.

Juneau County offers Nitrate well water testing working with the Wood County Health Department. Test kits can be picked up at the following locations:

Juneau County Health Department
200 Hickory Street
Mauston, WI 53948

Juneau County Land and Water
USDA Service Center 
1001 Division Street
Mauston, WI 53948

Juneau County also offers free Nitrate screening in office at the USDA Service Center. The screening, while not a certified lab test, does offer residents an idea of what the nitrate-N contamination is in their drinking water. 

What can I do about elevated nitrate-N in my drinking water?


If your well tests above 10 mg/L nitrate-N, do not boil your water!  Boiling water increases the nitrate-N concentration in the water.  Instead, switch to bottled water if there is an infant, small child, pregnant woman, or woman of child bearing age in your home.  Elevated nitrate-N concentrations are only a concern for water that is being consumed or used in the cooking of food and beverages to be consumed.  It is not a concern for daily tasks such as dish washing, laundry, bathing, etc.
To deal with elevated nitrate-N concentrations long term there are three options:
  • Bottled Water
  • Treatment SystemThere are a variety of treatment systems available to homeowners to treat water quality issues.  Common types of treatment systems for removal on nitrate-N include reverse osmosis, distillation, and anion exchange.  These systems can range from a single point of use system to whole home treatment.  
    If private well owners are interested in choosing a water treatment device for use in their home, they should always choose an approved device and a device that is specially designed to address the water quality concern or a specific contaminant.  Water treatment devices can be approved in two different ways:
    1. A Wisconsin Department of Safety and Public Services approval (i.e. listing); or 
    2. A listing by an American National Standards Institute (ANSI) accredited listing agency (e.g. NSF International The Public Health and Safety Organization, Underwriters Laboratory (UL) Safety Certification Company, or the Water Quality Association (WQA)).
       A product only needs to be approved by one of the agencies.  For either NSF or WQA products you may search by a specific product/manufacturer, you may search by product type (i.e. reverse osmosis) or you may search by contaminant (i.e. Nitrate).
    To view the list of Wisconsin Department of Safety and Public Service approved products for nitrate-N removal please click here.
             
  • New Well 
    Private well owners may consider installing a new well to try and achieve better water quality in their private well.  However, there is no guarantee that installing a new well that a private well owner will reach better quality of water.