This paper focussed on the features of actual water consumption and operating condition of wastewater recycling system in multi-use building, in order to obtain basic design data for the water balance between water supply and use of reclaimed water, which plays an important role of system performance in the stage of the planning, maintenance, and control. In this report, authors surveyed the tendency and amount of city water consumption, drainage water from the flow equialization tank, and pattern of reclaimed water consumption. And authors simulated the variation of water level in the reclaimed water receiving tank, the operating of treatment facility, and the quantity of make-up water into reclaimed water by the new set point of water level, for the purpose of optimization of operating condition.
