Threat to Personal Safety and Water Supply
Wells are considered abandoned when they have not been used for six consecutive months. Many accidents have taken place in which people or animals have fallen into abandoned wells.
Abandoned wells also provide a direct route for contaminants to enter aquifers below the surface. When open to more than one aquifer, abandoned wells may also allow deeper, salty aquifers to contaminate shallow freshwater aquifers. In addition, abandoned wells contribute to regional depletion of pressure head within an aquifer.
Preventing Injury and Contamination
Options exists for reducing the risk of personal injury or contamination of the water supply. These include restoring it to working order, capping it or plugging it.
The following are key steps to plugging the well.
Measure the dimensions of the well. This information is used to determine the volume of material needed to plug the well and to determine the quantity of standing water in the well.
Remove all obstructions from the well. Obstructions prevent plugging materials from reaching the bottom of the well, and create the potential for future settling and disturbance of the seal.
Disinfect the well by adding household bleach. The household bleach will kill any microorganisms that have fallen into the well while it was open.
Remove as much casing as possible. This removes direct conduit to the groundwater, removes annular space around the well, and allows native soil to bond with plugging materials.
Fill the well with plugging materials. The plugging materials restrict the matter movement from the soil surface to the groundwater. These materials need to be clean to prevent contamination of the groundwater and prevent bridging as the materials enter the well.
Complete the plugging report. The plugging report provides documentation that the well has been properly plugged. This material needs to be sent to the Texas Department of Licensing and Regulation and local groundwater districts.
Who can plug an abandoned well?
A landowner, a licensed driller or a licensed pump installer can legally fix an abandoned well.
What materials can be used to plug an abandoned well?
The different acceptable materials used to plug abandoned wells are
When plugging a well with a large diameter, clay or caliche soil may be used.