Air Emissions
The six existing ventilation shafts will be refurbished. Ventilation air will be drawn down the main access decline by means of ventilation fans located at the base of each ventilation shaft. Air will be directed, as required, throughout the underground workings by a combination of area ventilation fans, ventilation bulkheads, doors, brattices and ventilation ducting. Exhaust air will be upcast by means of the ventilation shafts. Shafts vary in length from ca. 50 to 130 m and are 3.5 m x 3.5 m in cross-section. Control of the main ventilation fans will be located close to the fans, with parallel controls at the surface within the surface housings. Back-up fans will also be provided at the surface to permit safe evacuation of the mine via the ventilation shafts. A permanent manway will be installed on selected ventilation shaft with an emergency exit door in the surface breakthrough housing. These will be secured against any unauthorised entrance into the mine workings.
By redirecting the air flows in the mine, the combined quantity of air exhausted from the mine’s ventilation shafts will not exceed emissions to atmosphere limits imposed by the EPA. Dust concentrations in the ventilation system exhaust will be very low, mostly due to the wet conditions in the mine that supresses dust.
Monitoring of the exhaust air will be carried out along with dust deposition monitoring on the lands around the mine to provide assurance to the EPA and local community that there is no impact due to air emissions.