Nitrate Contamination

Nitrate contamination found in some Scott County Well Water
Nitrate is a common contaminant found in numerous wells in Minnesota. Many of the wells tested in Scott County since 1978 have been found to have nitrate contamination in excess of 10 parts per million (ppm). Wells that are contaminated with nitrate in excess of 10 ppm should not be considered to be a safe source of drinking water. View a map showing the location of Scott County wells (PDF) that have tested positive for nitrate.

Please Note

Some of the tested wells were very shallow (less than 50 feet deep), so they will likely not represent the water quality of deeper wells that are located in the same area.

Nitrate Levels
Natural levels of nitrate in Minnesota ground water are usually quite low. However, where sources of nitrate such as fertilizers, animal wastes, or human sewage are concentrated near the ground surface, nitrate may seep down and contaminate the ground water. Nitrate is colorless, tasteless and odorless. Although nitrate in well water is normally not considered harmful to adults or older children, its presence indicates that other disease causing contaminants or microorganisms may also be present. Too much nitrate in drinking water can be harmful to young infant children and young livestock.

Checking Your Water
Well water should be checked every two or three years for indications of nitrate contamination, and more frequently if nitrate has been found before. Therefore, if the map shows that you live in an area where high nitrates have been found, it is especially important that you have your well water tested. Also be sure to test your water if you are planning on becoming pregnant, if infants will be using the water, or whenever there is an odor or noticeable change in water quality. If nitrate is found in your water at levels exceeding the health limit of 10 ppm, do not give the water to any infant under six months of age. Boiling will not treat the water (in fact, it will actually increase the nitrate concentration). Have your well inspected by a licensed well contractor. Scott County Environmental Health can also assist you in identifying and correcting problems with wells. It is important that you remove the sources of nitrate near the well once they have been identified.

To find out if there are high levels of nitrate in your water, simply click on the “How to Order a Well Water Test Kit” link on the left side of this page, or stop by the Scott County Community Development office at the Courthouse in Shakopee. We sell a Nitrate Testing Kit (including a sampling bottle, sampling instructions, and a pre-paid lab test) for $26.00, or you can send a check for $27.50 to have the kit mailed to you. If you have any questions, please call 952-496-8475 for more information.