Evaluating Biosolids Management Alternatives in Northeast Tennessee: A Cooperative Masterplanning Effort

Results of a multiple agency regional biosolids management study jointly conducted for five entities located in Northeast Tennessee are shared. The study focused on evaluating regional Class A, or other advanced treatment, management options meet current and future residuals production rates for the participant agencies. The participant agencies by participating in a cooperative masterplanning effort were able to leverage their investment in development of the masterplan such that each agencies “share” in the plan development was lower than if they had conducted independent planning efforts.Collectively the agencies currently generate approximately 4,900 dry tons per year of wastewater treatment residuals which are managed by land application and/or landfill disposal with operating costs ranging from approximately $80 to $260 per dry ton. Evaluations of selected Class A residuals treatment technologies and other advanced residuals treatment technologies included:• Aerated Static Pile Composting• Alkaline Stabilization/Pasteurization• Fluid Bed Thermal Oxidation• Centralized Thermal Drying• Decentralized Thermal DryingEstimated capital and net present operating costs were developed for each of the alternatives for comparison to the current residuals management practices in place for the agencies. Generally, the alternatives evaluated resulted in increased downstream operating costs for each of the agencies in addition to requiring varying levels of increased capital investment. Based on the increased capital and operating costs, when compared to the “status quo” a decision was made by the participant agencies to defer pursuit of a regional Class A residuals management alternative until a triggering event warrants additional expenditures.