City of Chilton-Composting Facility: Markets and Conceptual Design

Abstract

Yard wastes from the City of Chilton and organic wastes from two industrial firms were combined and composted in a pilot study. The finished compost was analyzed for: pH, nitrogen, potassium, phosphorous, calcium, heavy metals, organic matter content, and moisture content. Potential markets within a 50 mile radius of the city of Chilton were surveyed. Two facility design options were evaluated and cost of composting using each option was determined. Potential for alternative markets (mushroom farming) was also evaluated. Survey results suggest that the demand for materials similar to the compost exists. However, there will be a need to convince users of the advantages of compost generated by the city to those materials that are presently being used. Consumers may not be willing to pay any more than their present materials costs to purchase the compost. Most potential users surveyed had the means to transport and store compost at their facility. The two design options evaluated had different objectives. One was labor intensive, the other was capital intensive. The capital intensive option is being recommended because of the lower overall costs. An estimate of capital and processing costs is $17.91/cubic yard of compost. This cost is higher than the present disposal methods that the city and industries have for their organic wastes. Composting of these wastes is therefore not economically feasible. The compost produced by the project does support mushroom growth. Two strains of edible mushrooms did grow on the compost mixture, providing a secondary market for the finished product. This compost and mushroom combination could be used to provide jobs to handicapped workers and provide an outlet for the finished composted product.