Well Water Testing

Most private wells provide a clean, safe supply of water; however, contaminants can pollute private wells, and unfortunately you cannot see, smell or taste most of them. Consequently, private well owners should test the water on a regular basis. The decision on what to test water for should be based on the types of land uses near your well.

Racine County Public Health Division has well water test kits available free of charge. The Wisconsin State Lab of Hygiene (WSLH) does charge a fee for each water test. See the brochure and link below for more information.

The Health Department performs water sampling for bacteria and nitrates and conducts sanitary surveys at public, transient, non-community water systems such as motels, restaurants, parks, taverns, and gas stations.

Why Test?

As one of Wisconsin’s 700,000 private well owners or private well water consumers, you probably use groundwater for doing your family’s laundry, drinking, cooking, bathing and watering your garden. Municipalities are required to test their water supplies regularly to ensure the water is safe to drink. Since there is no requirement to test a private well except for bacteria when it is first drilled or the pump is changed, you are responsible for making sure your water is safe.

Most private wells provide a clean, safe supply of water; however, contaminants can pollute private wells, and unfortunately you cannot see, smell or taste most of them. Consequently, you should test your water on a regular basis. The decision on what to test your water for should be based on the types of land uses near your well.

The Two Most Important Tests:

Bacteria

Coliform bacteria are microorganisms found in the intestines of warm-blooded animals as well as in soil, on vegetation, and in surface water runoff. Finding coliform bacteria in a water supply is an indication that there is a potential for disease-producing organisms to be present also.

Coliform bacteria washed into the ground by rain or melting snow are usually filtered out as water percolates through the soil. However, poorly-constructed or unsealed wells, fractured rock outcroppings, sinkholes, and quarries may provide a path for coliform bacteria to enter groundwater.

Once in the groundwater, bacteria can easily pollute drinking water used by private well owners. Other bacteria, viruses and parasites, which can cause illness, can be in water containing coliform bacteria.

Private wells should be tested annually for bacteria and any time there is a change in taste, odor, color or appearance of the well water, or if work has been done on the well.

Iron and sulfur bacteria may also be present in well water. Although not a health threat, these two types of bacteria can make water smell and taste bad and plug or corrode plumbing equipment. The WI State Laboratory of Hygiene offers a test to detect iron bacteria.

Nitrate

Although nitrate is found naturally in many types of food, high levels in drinking water pose a serious acute health threat for infants less than six months of age. Nitrate is changed to nitrite in the stomachs of small infants. The nitrite then interferes with the blood's ability to carry oxygen, and symptoms of suffocation or blue baby syndrome can occur. This problem generally does not affect older children or adults. Research is underway to ascertain if nitrate causes chronic illness.

Sources of nitrate include fertilizer infiltration in agricultural areas, animal feedlots, sewage absorption fields, municipal and industrial wastewater, urban drainage and decaying plant debris.

Underground soil and bedrock structure and the direction of groundwater flow influence when and where nitrate is found. In some areas nitrate contamination may be associated with other groundwater contaminants.

A nitrate test is recommended for all wells and is essential for wells serving infants under six months of age.

The WI State Laboratory of Hygiene as well as private laboratories certified by DNR can test water for the presence of nitrate. If the levels are over 10 mg/l, the water should not be fed to infants under six months of age, or used to prepare formula. Nitrate is not believed to be a health concern for a pregnant woman or her fetus. Adults concerned with the yet incomplete and inconclusive research results regarding chronic illness, may wish to reduce consumption of water high in nitrate.

If nitrate levels are less than 5 mg/l, retesting every few years should be adequate. If the results are between 5 and 10 mg/l, more frequent, perhaps annual testing can be considered to monitor fluctuations in nitrate concentration.

Other Tests

Other tests for private wells are: pesticides, lead, copper, VOCs, PCBs, arsenic, radium, molybdenum, boron, radon and fluoride. Each specific test has recommendations as to which well should be tested and the frequency of the test.

For more information on well water testing, visit the dnr.wi.gov website.

TESTING KITS

The Racine County Public Health Division provides well water test kits for the Wisconsin State Laboratory of Hygiene (WSLH). The kit is free of charge, but each test has a fee.

Please call (800) 442-4618 for pricing and test availability or visit WSLH website: www.slh.wisc.edu

Kits are also available at:

Town of Waterford Town Hall
415 N Milwaukee Street
Waterford, WI
(262) 534-2350
M-F, 8 AM - 4 PM

Yorkville Village Office
925 15th Avenue
Union Grove, WI
(262) 878-2123
M-F, 8 AM - 4:30 PM