Wastewater Characteristics and Quantities Associated with Fruit and Vegetable Processing in Michigan

Abstract To estimate the amount of wastewater produced by Michigan crop commodity food processors, an exhaustive search of government sites, electronic resources, and interviews with government officials and commodity groups was conducted. Values were not directly available however, data was found that allowed for by multiplying typical wastewater characterization parameters by the annual amount of each commodity processed in Michigan. The commodities in Michigan that have been found to be of most significance in terms of wastewater production and characteristics were the following: apples, asparagus, blueberries, carrots, cucumbers, carrots, cucumbers, grapes, potatoes, pumpkins, snap beans, squash, sweet cherries, tart cherries, and tomatoes. Introduction Surrounded by the Great Lakes, water resources are one of Michigan’s greatest attributes. Groundwater is an important natural resource and understanding the quantity and nature of discharges that have the potential to impact groundwater is critical to select priorities for its protection. In Michigan, groundwater is often hydraulically connected to surface water and may provide base flows to streams. As a result, groundwater may influence surface water. Further, about half of the state’s residents rely on groundwater for their drinking supply (IWR 2006). Consequently, protecting Michigan’s groundwater resource is imperative for the health and wellbeing of her citizens. Recent water related publicity concerning food processing wastewater has sparked interest into examining alternative treatment options. Cost/benefit studies are needed to allow for scientifically based environmental protection that will minimize the burden on Michigan’s agricultural industries. An understanding of the quality and quantity of wastewater produced by Michigan food processors is the first step in determining the magnitude of the problem and developing cost effective treatment strategies. This data will allow for researchers to prioritize commodity processing and will assist extension educators in offering the necessary programs. A specific emphasis is on food processors that are not served by public wastewater treatment plants. These food processors often irrigate with their process wastewater, which has a greater potential environmental impact. In addition to exclusive wastewater treatment options, the use of technologies that both effect treatment and enable the beneficial use of byproducts should be considered. Because of the high sugar content in many food processor wastes, a demonstrated option is anaerobic digestion. This option removes organic matter by converting it to biogas, water, and intermediates. A primary