Home Improvement: Well Water Testing

Location, Location, Location. 

Realtors are aware that location is important to home buyers. Many home buyers dream of getting away from the city bustle and heading toward the quiet of the country.  Buyers need to learn what comes with the country life and what does not. One thing that does not normally come with a country home is municipal water services. 

Residential properties in rural areas often get their water from private wells.  According to the EPA, 15 percent of Americans rely on individually owned and operated sources of drinking water.

A question a potential buyer will or should ask is, “How’s the well and is the water good?”  After all, they will drink, cook, shower, wash and clean with this water every day.

Wells can be affected by many things like the construction and maintenance of the well and pump. The location of the well and the septic tank and lines can affect the well and the water quality.

Some issues with drinking water quality will be obvious. These can include unusual smells, tastes or colors, hard water stains or particles in the water.  Other contaminants are not obvious at all.  The water will look and taste and smell fine.  A few contaminants, like bacteria or nitrates, can cause serious medical issues. Those contaminants can only be detected through laboratory testing of the water. City water is tested regularly by the water company.  Private well owners are responsible for regular testing.

Some local governments and many lending institutions require well inspections and water testing before a home with a private well can be sold.  Testing of the water and inspections of the well should be done prior to listing a property.  This allows the seller to identify and correct any problems that could affect the marketability of the home.  Just like a leaky roof, a contaminated water supply will make a house worth less and it will take longer to sell. 

The EPA suggests the minimum initial tests should include coliform bacteria and nitrates/nitrites.  The lending institution will most likely require the same tests within 30 days prior to closing.

Coliform bacteria is the standard used for the bacterial quality of drinking water. Coliform is not a single type of bacteria, but a group of “indicator bacteria”.  They live naturally in the intestinal tracts of warm-blooded animals and are found in sewage.  Some can also be found naturally in the soil and surface waters, such as rivers, lakes and ponds.  These bacteria do not usually cause illness by themselves, but testing for specific disease-producing bacteria is complex, time consuming and expensive.

A positive result for coliform bacteria in the water sample indicates surface water or sewage may have entered the well and contaminated the water supply with disease causing organisms. 

Nitrate is a compound that forms naturally when nitrogen combines with oxygen.  Groundwater normally has a low concentration of nitrates. But, sometimes higher levels can be found.  Nitrate is a common contaminant in Illinois groundwater.  High levels can result from overuse of fertilizers near the well, and runoff or seepage from septic fields, animal feedlots and farm fields.

High levels of nitrates do not affect adults, but it can pose a serious health risk to infants under one year of age.  The high nitrate level can cause a condition known as “blue baby syndrome”.  The infant’s blood is not capable of carrying oxygen, causing asphyxiation and the skin turns blue.  Medical attention should be sought immediately. For this reason, pregnant women and infants less than one should avoid using water with a high nitrate level for drinking or cooking. The water should not be used for preparing  infant formula.  Boiling the water will not help. That will actually increase the nitrate level in the water.

The water should be tested by a state certified laboratory.  The lab will provide sampling instructions and collection containers or bags. A listing of certified laboratories can be found here or contact your local health department.

The EPA establishes limits on the concentration of contaminants that would pose a health threat in public drinking water supplies. Private well owners are generally not required to test their drinking water to meet those standards. But, lending institutions usually use the same standards as the EPA for loan approval.  The EPA limit for coliform bacteria is zero.  The EPA limit for nitrates is 10 mg/L and the limit for nitrites is 1 mg/L.

If the test shows positive for coliform bacteria, the well should be resampled immediately. This eliminates the possibility of contamination of the original sample during collection from improper collection techniques.  If the resample is still positive, the water should be boiled before it is used for cooking or drinking and the well system will need to be disinfected.  These methods involve chlorine, ultra-violet light or ozone treatments. If the resample is negative, the water supply can be considered safe for drinking.

Nitrates can be removed for the water with water treatment systems that use reverse osmosis, distillation or ion exchange.  A water softener will not remove nitrates.

Well water conditions change regularly.  It is recommended to test the well at least annually.

A properly constructed and maintained well can provide years of service and safe drinking water will add value to any home. 


Centers for Disease Control and Prevention. cdc.gov.

Illinois Department of Public Health. dph.illinois.gov.

Illinois Environmental Protection Agency. epa.illinois.gov.

Water System Council. watersystemcouncil.com.