Private Well Testing

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Wells and drinking water

All Carver County residents rely on groundwater for their water supply, whether it comes from a municipal water source or their own private well. Public water systems are tested regularly for a variety of contaminants. For private wells, regular testing is up to the well owner.

Well water quality can change for many different reasons including weather, repair of plumbing, age of well equipment, activities at the land surface, etc. The Minnesota Department of Health recommends that private wells be tested annually to every two years depending on the potential contaminant.

Learn more about these well water contaminants.

Test For	Frequency
Total Coliform Bacteria	Every year
Nitrate	Every other year and before giving to an infant
Arsenic	Once
Lead	Once
Manganese	At least once before a baby drinks the water

Visit the Carver County Groundwater Plan for more information on groundwater quality and potential contaminants.

Well test kits

If you own a well, you are responsible for testing its water regularly.

Three types of test kits, provided by RMB labs, are available.

Nitrogen and E. coli test kit. Good for yearly testing and day care providers.
Nitrogen, E. coli, arsenic and mangenese test kit. Good for new homeowners.
Nitrogen, E. coli, arsenic, lead, and mangenese test kit. Good for those with older homes.

Pick up your test kit

Carver County Government Center at 600 East 4th St. Chaska, MN 55318
University of Extension office 11360 Highway 212 W Ste 4. Cologne MN 55322-8019

Dropping off kit

Once water is collected, test kits should be dropped of at the RMB Labs in Bloomington.
Cost varies by kit and is paid to the lab. The test kits themselves are free to pick up.

For questions, contact Tim Sundby at 952-361-1816 or tsundby@carvercountymn.gov.

For information can be found on MN Department of Health's water quality, well testing, and well disinfecting page .

Understanding test results

Contaminant	What to look for
Total coliform bacteria	0 colony forming units
Nitrate	Must be less than 10 milligrams per liter (mg/L)
Arsenic	10 micrograms per liter (µg/L) Recommended to be as close to 0 as possible.
Lead	0 parts per billion (ppb) No know safe level of lead.
Manganese	100 micrograms per liter (µg/L) or less for infants under 1 year old. 300 micrograms per liter (µg/L) or less for household members 1 year or older.

If test results show that your water exceeds the safe limit for a particular contaminant, you can contact the Well Management Section of the Minnesota Department of Health for additional information: 1.800.383.9808 or 651.201.4600.

Sealing unused wells

Unused wells that are not properly sealed pose a safety, health, and environmental threat to families and communities as well as a potential legal risk to the homeowner. The State of Minnesota requires that abandoned or unused well be sealed by a well contractor licensed in the State of Minnesota. Carver County's well sealing programs provides financial assistance to help residents seal unused wells.