To devise a suitable method for the treatment of wastewater, the organic loading of the various processes involved and methods for its reduction were investigated. As raw materials, potatoes were used in great quantities. Potato recovery in the processes was about 96% but the organic loading was very high. Thus, if some methods other than water washing could be devised to enhance the yield of intermediate products, a marked decrease in organic loading would be possible. Furthermore, we propose some methods for the reduction of organic loading, which are modification of the water washing method.