A cooling system has been installed at Mulgrave Mill so that water used by its single pass cooling system is returned to the Mulgrave River with a minimal increase in temperature. It represents an acceptance by Mulgrave Central Mill Co. Ltd of a responsibility for its mill operations to have as little effect on the environment as possible. Principal elements of the system are a gravity cooling water supply pipeline to a pond, a cooling water spray pond, a spray system and an outlet. The system is cost effective, fits in with the limited space available for factory operations and can be used in conjunction with the single pass cooling system currently in use at Mulgrave Mill. River temperature monitoring revealed a temperature increase of only 3 degrees Centigrade compared with a 12 degree Centigrade increase in the previous year before the cooling system was installed.