How to decommission a well

Staff from the Quinte Conservation Centre gave a lesson on how to decommission a well today. Mark Boone, the centre's first hydrogeologist, was the speaker.

  1. Boone spoke to the crowd and answered any preliminary questions before he gave a demonstration on the importance of a healthy well. He explained that a contaminated well could harm surrounding ones.
  2. In his demonstration, Boone used food colouring and a model of an underground well system. You can see in the picture below that at certain points the red colouring has leaked into the soil and into other wells.
  3. Boone gave the audience some quick facts about bentonite grout, which is used as a sealant once the well has been cleaned out.
  4. A video camera can help determine what is inside the well. Boone explained that every well is different, so there can be a number of surprises if it's not thoroughly inspected.
  5. The group then traveled to the site of a well decommissioning. It had already been filled with seven feet of sand. The crew was adding bentonite chips to create a sealed barrier near the top of the well.
  6. A worker from Well Busters started layering down bags of the bentonite chips. Once he emptied the bags, he stomped on the pile to make sure it was nice and packed.
  7. Bentonite grout is then added to create a barrier. The worker described the grout as a putty-type substance. "Since the grout never fully solidifies, it never cracks and that's why this works," he explained.
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  9. The grout needed to set and expand before the final steps to seal the well could be complete. Boone took questions from the crowd.
  10. The last step involves filling in the rest of the hole with clean sand and then the original ground soil.
  11. To wrap up the decommissioning of a well, all of the required paperwork must be filled out. Here is a closer look at a well decommissioning record form.
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