Why Should Unused Wells Be Properly Abandoned?
There are many reasons why an unused well should be properly sealed and abandoned. An unused well which is not properly sealed can pose a safety hazard. This was exemplified when the nation witnessed the rescue of a child in Texas from an improperly abandoned well several years ago. This well was less than ten inches in diameter.
The prevention of ground water contamination is another reason for proper well abandonment. Four ways that an unsealed or improperly abandoned well could contaminate ground water are:
- Intermixing of waters between aquifers
- Surface water enter the aquifer
- Direct disposal of contaminates down the well
- Bacterial contamination from decomposition of waste products
Another reason to properly seal a well is to prevent further loss of confining pressure. Sealing a well that penetrates a confined aquifer helps to preserve the confined conditions. These confining conditions allow the water to reach a certain level in a well. A reduction in the confining pressure may cause water levels in neighboring wells to drop.
What Are The Proper Methods To Seal An Unused Well?
Grout is the proper material to use when abandoning a well. Grout is a fluid mixture of water and cement or water and bentonite that is of a consistency to be pumped through a small diameter pipe. Before a well is sealed with grout, the following steps must be taken:
- Remove the casing if possible. If the casing cannot be removed, slotting the casing or splitting the entire length is recommended.
- The casing, if not entirely removed, should be cut off at least three to five feet below grade and removed.
- Remove all pumps, screens, tools, fittings, pipe, etc. from the well.
In case of a dug well, loosely laid stones, bricks, etc. must be removed to a depth of at least three feet below grade. In some instances, clean clay can be used in conjunction with grout to seal dug wells.
Who Should Perform Proper Private Water System Abandonment?
Based on the difficulty in sealing many wells and the equipment and knowledge required, it is recommended that well sealing be performed by a private water systems contractor registered with the Ohio Department of Health. However, a homeowner can properly abandon their own private water supply. Recently adopted Ohio Administrative Rules have established procedures for sealing all private water systems. All cisterns and hauled water storage tanks that are permanently out of service shall be emptied of all accumulated water. At least one wall of the cistern or hauled water storage tank shall be removed to prevent the accumulation of water. All entrances and drains into the cistern or hauled water storage tank shall be disconnected and sealed. The cistern or hauled water storage tank shall be completely filled with an inert solid material to prevent collapse.
Who Must Be Notified When An Abandoned Well Is Sealed?
A well sealing report must be submitted to the Ohio Department of Natural Resources (ODNR), Division of Water. An appropriate form can be requested from the Fulton County Health Department. Ohio Private Water System Rules require that the local Health Department be notified prior to sealing a private water system.