Stringent environmental regulations and economic expansion in the recent decades have justified the need for sustainable water usage in the process industry. This work presents a mathematical formulation that simultaneously optimizes the production schedule and utility consumption in multipurpose batch plants. A multipurpose batch plant is a type of batch plant capable of manufacturing one or multiple products with varying production recipes. Washing of processing units is regularly performed in such plants to preserve the integrity of each batch. The amount of wastewater generated by washing operations is minimized in this work through the exploration of direct, indirect, and regeneration reuse opportunities within the plant. Water regeneration is achieved through partial purification of highly contaminated wastewater using electrodialysis (ED). A design model for ED is included in the formulation to allow for simultaneous optimization of water and energy use in the regenerator. The formulation is applied to two case studies and yields decreases in freshwater usage by 41.4 and 37.5%, respectively, hence increasing the overall plant profit.