USED IN SHIP BUILDING BALLAST WATER SUPPLY SYSTEM AND METHOD WITH THE EFFLUENT WATER

The present invention relates to a ballast water supply system using an effluence in a shipbuilding and a supply method thereof. Provided is the ballast water supply system using an effluence of shipbuilding which includes: a sand filtration tank filtering an effluence used during shipbuilding and composed of sand layers filtering floating substances; a chloride supply tank supplying a predetermined amount of a chlorine disinfectant to the effluence filtered by the sand filtration tank to sterilize and disinfect the effluence; a ballast water storage tank storing and retaining the filtered effluence in a predetermined period and agitating and mixing the chlorine disinfectant supplied from the chloride supply tank with the effluence; and a ballast water supply unit installed on one side of the ballast water storage tank and supplying the processed effluence to a ballast water tank. According to the present invention, the ballast water supply system is able to simultaneously supply a large amount of water to prevent the water shortage and to eliminate the cutoff of water supply in accordance with stable supply of ballast water, thereby obtaining a cost-saving effect.