The work will consist of excavation of the spoil material around the mine subsidence area. An existing concrete structure from the original mining is visible in the subsidence depression. Excavation will extend to the lowest elevation of the face of the existing concrete structure. Side slopes for the excavation area of 3:1 to 4:1 will be required, and benching may be necessary to provide a safe working area. Once the existing concrete structure is fully exposed, a concrete cap will be constructed to fully close the mine opening. It is unclear if the concrete structure is associated with the slope shaft or an air shaft of the Goldsberry Mine. Methane monitoring is the responsibility of the contractor, and if methane is encountered, the contractor must immediately implement a plan to secure the area. Methane monitoring and control is incidental to the overall completion of the project.
