Decommissioning or abandoning a well is the process of filling in a well or hole with material to render it impossible to extract any additional water from the well. Wells that have been deemed no longer useable whether because of low production, contamination issues, wells that are unable to stay open from debris or changes in the property, usage of the property or structures making the location of the well no longer feasible are just a few reasons as to why a well would need to be abandoned.
Well abandonment companies often perform well abandonments with a grouting machine where they lower what is called a tremie pipe down to the bottom of the well. Mix the abandoning material on site at the surface and then fill the well with the use of a pump that pumps the material down the tremie pipe while they slowly remove the pipe a few feet at a time to ensure proper fill age of the material in the hole without any bridging.
In some instances where water will still need to flow “through” the well approved gravel type material is used to fill the well. In either instance local governing authorities usually require the well head to be cut below ground with a cement pad poured over the well insuring no outside contaminants from entering the old abandoned hole.
Well decommissioning costs can vary because of the amount and type of materials that need to be used. Typically, well abandoning is charged out on a price per foot basis.