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Environmental Resources

Well Testing
How well is your well?

​Residents with private wells for drinking water can have their water tested for nitrate for free during the Dakota County Fair week—Monday, Aug. 5 through Friday, Aug. 9.

Water samples may be dropped off anytime between 8 a.m. and 4:30 p.m. at the Physical Development Division office on third floor of the Western Service Center, 14955 Galaxie Ave. in Apple Valley. Dakota County will test the samples and send the results to well owners.

If the drinking water in your home comes from a city water system, this testing service is not for you.

Bring one cup of water in a small, clean bottle or jar. Collect the water sample just before leaving home. Clearly label samples from different wells. To check if a water treatment system, such as a reverse osmosis unit (not a water softener), is working properly to remove nitrate, bring samples marked before and after.

Many private wells in Dakota County contain nitrate. Nitrate is the most common source of groundwater contamination in both Dakota County and the United States. Major sources of nitrate contamination can be fertilizers, animal waste and human sewage. Dakota County highly recommends testing private drinking water supplies annually.

A water supply with a nitrate concentration of more than 10 milligrams per liter is a significant risk to infants six months of age and younger. Elevated levels of nitrate in water and baby formula prepared from that water can cause Blue Baby Syndrome. Long-term health effects to older children and normally healthy adults are not yet known or agreed upon by scientists. Boiling water high in nitrate increases its concentration and does not make the water safe to drink. Nitrate can be removed with a reverse-osmosis or distillation treatment system.

For information about private wells and how to reduce or remove nitrate, contact the Dakota County Environmental Resources Department at 952-891-7000.