A Washdown system is a canopy of piping that is near the ceiling, walls, floor and coal handling equipment. Accumulated dust from coal handling in conveyor areas is removed by periodic hose washdown. It is especially dangerous in the event the accumulated dust becomes airborne from areas above the floor. Manual hose washdown must be carefully and consistently monitored to insure a quality job of removal. The spray nozzles are appropriately spaced along the complete length of the piping. The system is divided into general areas and zones in each coal handling plant. Normally only one zone is operated at one time. This depends on the design of the water supply system and drainage system. It serve three major industries; forestry, mining and construction.