Well Decommissioning

Have an Abandoned, Out of Service Well?

 If you have an old well that is out of service, the best course of action is to have it professionally decommissioned. Decommissioning ensures that the well is safely sealed, preventing any potential groundwater contamination or safety hazards. The first step is to contact a qualified well decommissioning service, like Pacific Geotechnical, who can assess the condition of your well and determine the appropriate method for sealing it. Our team will guide you through the process, ensuring that everything is done in compliance with local regulations and with minimal disruption to your property.

Types of Abandoned Water Wells

 

  • Drilled Wells: These are typically 6-8 inches in diameter and made with steel casing. They often require a drilling rig to remove or properly seal the well.

  • Dug Wells: These wells are usually wider, measuring 2-3 feet in diameter, and are lined with concrete or other materials. Dug wells may be 10 to 30 feet deep and generally require different equipment, like an excavator or crane, for decommissioning.

The Well Closure Process

  • Top 3 Feet of Casing Removed: The top section of the well casing is removed to prevent any future use and to allow for a secure seal at the surface.

  • Grout or Bentonite Seal: A watertight seal made of grout or bentonite is installed, extending 4 inches above the remaining casing, 1 foot below it, and 1 foot beyond the casing’s edge. This seal prevents surface contaminants from entering the well.

  • 5-Foot Watertight Seal: An additional 5-foot section of watertight seal is placed further down the well, using grout or bentonite, to ensure no water or contaminants can migrate up or down the well shaft.

  • Treated Sand or Gravel: The area between the seals is filled with treated sand or gravel, providing stability and preventing any collapse of the well structure.

  • Native Soil Mounded for Settlement: Finally, the well is capped with native soil, mounded slightly to account for future settlement, ensuring a secure, natural finish that blends with the surrounding landscape.

Ready to Close a Well? 

Review the checklist below to help determine if it’s time to close a well on your property. If you do, simply include your details below and someone from our team will reach out to schedule your free consultation.