The invention features an apparatus and a method for supplying ozonated water to more than one process tool. Ozonated water of a first concentration received from an ozonated water generator and water received from a source are mixed to produce ozonated water of a second concentration. The ozonated water of a second concentration is supplied to a first process tool. Ozonated water from the ozonated water generator is supplied to a second process tool while supplying the ozonated water of the second concentration to the first process tool.