Wells that are no longer needed are an open source for surface contaminates and a safety concern. If you require well decommissioning, H2O Well Service has the equipment and the knowledge to meet all the state requirements.
All well abandonments require the casing to be removed or perforated and grouted from the bottom of the well to the surface, a drill rig is used to pull or perforate the casing then a Tremmie pipe (small pipe usually 1 3/4 or 1 1/2) is lowered to the bottom of the well. Sealing material is pumped in until it reaches the surface at which time the pipe is removed. The top three feet of casing is cut off and a cement cap is installed.