Wellhead Protection Plan
Sealing Unused Wells
What is an unused well and why is it a problem?
A well that is not in use, sometimes referred to as an “abandoned” well, can be a potential threat to health, safety, and the environment. Wells that are no longer used may be buried or forgotten. Often they have not been sealed properly. Sealing is the process of clearing an unused well of debris and filling the well with a special material called grout. A licensed well contractor must do the sealing. Unused wells that have not been properly sealed can be a source of groundwater contamination, potentially affecting nearby drinking water wells. They may threaten the quality of water in the city water wells, your neighbor’s well, or even your own well. Groundwater is the main source of drinking water for three out of every four Minnesotans. Protecting groundwater is everyone’s business. As wells age, the casing may rust, joints may leak, the pump may become stuck in the well, or the well may fill with debris. If the well is covered with boards or concrete, the cover will eventually decay and break open. Surface water runoff, debris, and other contaminants can then enter the well. A well may be taken out of service for a variety of reasons. It may no longer provide enough water. It may not have been repaired when it needed to be. It may have become contaminated. A well may be “lost” or abandoned when property changes hands, or when use of the land changes from agricultural to industrial or residential. Old, unused wells are easily forgotten.
How do unused wells threaten the groundwater?
Groundwater is found in underground geologic formations called aquifers. The layers of rock and soil that lie between an aquifer and the surface, or between aquifers, typically act as a natural barrier against the spread of contamination. However, an unused, unsealed well can provide an open channel between the surface and an aquifer or between a shallow aquifer and a deeper aquifer. An unused well can act as a drain allowing surface water runoff, contaminated water, or improperly disposed waste to reach an uncontaminated aquifer.
Do unused wells pose any other problems?
If unsealed large diameter wells are not covered or otherwise protected, the open well hole can be a safety hazard, especially for childres and animals.
What does the law require?
By law, a well must be in use, be under a maintenance permit, or be sealed by a licensed well contractor. A well must be sealed if 1) the well is not in use, 2) the well is contaminated, 3) the well has not been properly sealed in the past, 4) the well threatens the quality of groundwater, 5) the well otherwise poses a threat to health or safety. If you have an unused well and wish to keep the well for future use, you must apply for a special maintenance permit from the Minnesota Department of Health. The permit requires an annual fee, and is only issued if the well meets minimum sanitary requirements.
How can I find out if I have a well on my property that is not in use and not sealed?
Whether you live in the country or in town, you could have one or more wells on your property, which are not in use and not sealed. If you live in town, there may be one or more wells that were used before city water became available, or a well that was used for watering lawns and gardens. If you live in the country, wells may have served current or former houses and barns. To locate old wells, it may help to:
- Find out when your home was built and when public water was available in your area. If the house was built before public water was available, there was likely a well on your property.Â
- Look for any physical evidence of a well on your property such as a well casing, pipe, or water pump; water pipes which may indicate the presence of a well; a small room, often in the basement, that may have housed a well or a small building located away from the house; a windmill or water pump; or a depression in the yard.
- Consult former owners of your property, or people who have lived in the area a long time. They may remember the locations of old wells.
- Look at old photos of your property. They may show windmills, houses, barns, or outbuildings where a well may have been located.
- Consult city and county records of building and land use permits.
- Consult the Well Disclosure Certificate available from the MDH, required for all property transfers in Minnesota since November 1, 1990 to obtain specific information about the location and status of wells on your property. Minnesota law requires any owner of property, which is sold or transferred, to disclose to the buyer the status of all wells on the property.
What does a well look like?
You can often see the casing of an usused well sticking up out of the ground. Look for a metal pipe, typically from 1 1/4 inch to 6 inches in diameter. Wells that were dug rather than drilled may appear as a ring made of concrete, tile, bricks, or rocks in the ground or pit. The ring could be anywhere form 12 inches to 36 inches in diameter, or even larger. A windmill, an old shed that was used as a well house, or an old pump may mark the locations of a well. A drepssion in the ground may indicate a buried well that hasn’t been sealed. If you had a well inside your home, a pipe sticking up out of the floor, possibly stuffed with rags, could be a well casing. Wells were often housed in a “basement offset”, a small room attached to the basement, often located under exterior concrete steps. A glass block fitted into a step or concrete patch could be another clue.
How are wells sealed?
State law requires that a licensed well contractor must do well sealing. Don’t try to do it yourself. A licensed well contractor has the necessary equipment and expertise to seal your well properly. The contractor can also handle all the necessary paperwork. To find a contractor, look in the Yellow Pages under Well Drilling and Service. The MDH also has a list of licensed contractors on the MDH Well Management section website at www.health.state.mn.us/divs/eh/wells/lwc
How much does it cost?
The cost of sealing a well can vary considerably. For shallow, small diameter wells like those found at some homes and many lake cabins, the cost typically ranges from $300 to $600. Deeper, larger wells will cost more to seal. Things like access to the well, special geological conditions, debris in the well, and depth & diameter of the well will affect the cost of well sealing. Also, if a contractor is already on the site drilling a new well, the cost of sealing an old well will often be less because of a special trip to the site is avoided. The same is true when people get together and arrange to have a number of old wells in a community sealed at the same time. It is always a good idea to get several estimates on costs. Some local governments offer cost share programs to help pay for part of the cost of sealing wells. Please contact the MDH or the local Soil and Water Conservation District for details.
What if I have an old well on my property and I only use it for watering my yard or garden, do I have to seal it?
Minnesota law does not require a well, which is in use, to be sealed unless it is causing, or has the potential to cause, a health problem or contamination of the groundwater. Your well is considered to be “in use” if you use it on a regular basis. If you sell or transfer the property, the well will have to be disclosed to the buyer at that time.
Where can I get more information?
MDH District Office
625 North Robert Street
PO Box 64975
St. Paul, MN 55164-0975
651-201-4600 or 800-383-9808
State or Federal programs offering grants and low interest loans for well contruction, repair, and sealing.
Well Sealing Financial Assistance