Pretreatment Systems – A Bridge to Composting at Virginia Department of Corrections Facilities
By all counts, Virginia’s Department of Corrections (VA DOC) is a very large organization. It is made up of 42 facilities housing nearly 30,000 offenders and 10,000 staff. Its agribusiness operations consist of 24 prison farms covering 16,000 acres and 50 greenhouses. The agribusiness operation produces vegetables, hay, forage, fish, grain, apples and raises dairy cattle, beef cattle and swine. Half of the produce and all of the milk consumed by offenders are grown on prison farms.
Food waste comprises between 50-55% of the total waste stream of their operations and is the largest portion of their disposal costs. Managing food waste is complicated in a prison environment. Not only is it heavy, smelly and expensive to haul to the landfill but it also presents a security risk that VA DOC has to vigilantly monitor. Security staff must inspect all trash bags and containers leaving the prison perimeter before it can be disposed. Between the growing financial costs and potential security risks of disposing of trash, Lois Fegan, VA DOC’s Recycling and Sustainability Manager, was determined to find a more effective way to manage the food waste and recyclable materials Virginia’s prisons generate.
Fegan has been implementing a plan to bring food waste composting at an additional 17 prison facilities, on top of the eight that currently compost food waste. Her goal is to provide all of the remaining facilities, 42 in total, with access to composting within the next 5-8 years. However, some facilities are more challenging than others. Composting areas are located outside of the prison perimeter and require support from the offender population to manage them. This is not possible for the highest security units as offenders are not allowed to work outside of the prison grounds. This led Fegan to explore how pretreatment technologies such as food dehydrators could help bring facilities with more challenging circumstances into VA DOC’s composting program. The primary benefit of dehydrators for Fegan is their ability to reduce the volume of material upwards of 90%, which not only significantly reduces the amount of trash to be hauled to landfills but also produces an output that can be transported more economically to off-site composting sites or utilized by facilities that manage farms or onsite greenhouses. For onsite uses, the dehydrated material is mixed into greenhouse or garden bed soils in a ratio of one part dehydrated material to five parts soil. Another benefit of the EcoVim dehydrators Fegan cited is improved odor and pest control. The dehydrated material controls insects within kitchen areas and rodents and larger animal pests in composting areas located outside of the prison’s perimeter.
Fegan has also explored other beneficial uses for the dehydrated materials such as fish or animal feed but has encountered obstacles that may preclude these potentially valuable applications. One obstacle to producing fish or animal feed is the requirement to produce a standardized product with a consistent nutrient profile. Prison meal menus vary daily and across facilities, so standardizing nutrient profiles of a finished product is nearly impossible to achieve. Offenders at one facility have been very successful in raising tilapia fish that are then filleted, flash frozen, and sent to other facilities. But in addition to the challenge of producing a standardized product, the dehydrated food would have to be encapsulated into pellet form to avoid clogging the water filtration system that is critical to maintaining water quality and fish health. So for now, Fegan is focusing on converting the output of dehydrators into mature compost.
Waste audits performed by Fegan indicate that 60-65% of the waste generated by VA DOC facilities is compostable. Preliminary return on investment calculations suggest that the savings from reduced trash hauling may be enough alone to cover the initial purchase of dehydrator units and associated operational expenses. The additional value of the compost to improve soil health on farms, greenhouses and for landscaping prison grounds have not been factored in as these are different depending on the facility.