Because nitrate is tasteless and odorless, water must be chemically tested to determine if it is contaminated. Many laboratories in Ohio will test private water supplies for nitrate. To have your water tested, you must get a sample container from the laboratory, draw the sample as directed by the lab and get the sample to the lab as quickly as possible to ensure a reliable test. For information on testing labs in your area, contact the county Extension office or local health department.
Accurately determining the nitrate level in a well can be difficult since nitrate levels vary according to the time of year. For this reason, spring is the best time to test since snowmelt and rains will leach any excess nitrate into the groundwater. A water test done in late fall can be misleading because the wed may be temporarily low in nitrate if there have been no heavy rains.
To protect the health of your family and livestock, annual water tests should also be made for the following
For more information about water testing, refer to Ohio Cooperative Extension Fact Sheet AEX-314.
If your well has been tested and the report shows that the water is contaminated with high nitrate levels, you must immediately stop feeding it to infants. As alternatives to contaminated water, you can plan to breast feed, feed formula prepared with bottled distilled water or feed premixed infant formula.
The easiest way to deal with a contaminated well is to find a new, clean source of water such as a spring, a cistern or a new well. In addition, water from farm ponds is usually low in nitrate because algae use nitrate as a nutrient source. If you do not have access to a new water supply, the contaminated water can be treated to remove the nitrate. However, only long-term nitrogen management can prevent further contamination.
When your report comes back from the lab after the water test, the nitrate concentrations can be reported either as nitrate (NO3) or as nitrate-nitrogen (N03-N). Be sure to know which reporting system is being used since the acceptable concentrations of each are considerably different. If the lab reports its results as nitrate (NO3), the drinking water quality standard is 45 milligrams per liter (mg/l). If the lab reports its results as nitrate-nitrogen (NO3-N), the drinking water quality standard is 10 milligrams per liter. A milligram per liter (mg/l) is also equal to a part per million (ppm). If you are unsure of how to interpret the report, contact the lab, the county Extension office, or local health department. It is important to check the lab report carefully because the two systems are frequently interchanged.