The Minnesota Department of Agriculture, Dakota County, and the Dakota County Soil and Water Conservation District have teamed up to offer area residents free nitrate testing clinics. Homeowners who rely on private wells for their drinking water supply should test for nitrates on a regular basis.

Free nitrate testing clinics that will be held from 5-8 p.m. on:

• Thursday, May 2, at the Dakota County Extension and Conservation building, 4100 220th St. W., Farmington

• Thursday, May 16, at Hampton City Hall, 5265 238th St. E.

• Wednesday, June 5, at Hastings City Hall, 101 Fourth St. E.

In order to participate in the testing, homeowners must bring at least ½ cup of water in a container. To get a good sample, allow the water to run five to 10 minutes before filling the container. Homeowners with distillators, reverse osmosis or other nitrate removal systems could take two water samples - one before and one after the treatment process. This will determine if the nitrate removal system is working. Homeowners with just a water softener need to take one sample, either before or after the water passes through the water softener. Only water from private wells will be tested.

Samples should be taken no more than 24 hours before the testing, and they must be refrigerated. Samples should be cool when arriving at the clinic. To ensure accuracy, homeowners should mark the bags with their name, phone number and a well identification number if more than one well is sampled.

Homeowners will remain anonymous.

Results are given directly to the homeowner immediately after testing. If the nitrate level in a sample is elevated, clinic staff can refer the homeowner to certified labs that will retest the water.

Nitrates are the most common contaminants in Minnesota's groundwater, and a significant number of wells in the state have high nitrate levels.