Estimation of "Wash-and-Rinse" Wastewater Quantity from Food Processing Industry

What are the best methods for estimating the quantity and quality of "wash-and-rinse wastewater" generated from the Food Processing Industry? Is there a method to estimate the quantity of this water generated from Small, Medium and large scale agro/food industries separately?  Can it be reused in food/agro-processing industries or should it be disposed? We are currently doing research on "wash-and-rinse wastewater collection, treatment and reuse in food and agro-processing micro/small, medium and large scale industries. If you know some case studies please share them.