Evaluation of Biosolids Utilization Options for the Capital Regional District, Victoria, BC

The Capital Regional District (CRD) in Victoria, BC, evaluated biosolids utilization alternatives as part of a planning effort for the Core Area Wastewater Treatment Program (CAWTP). A two-stage analysis was conducted to identify a biosolids management program that met the CRD's goal of cost-effective, environmentally sustainable, and socially responsible wastewater treatment. If managed appropriately, biosolids production and utilization could provide multiple benefits to the utility including reduction of its carbon footprint, revenue from the biosolids product, and additional resource recovery.Analysis revealed the most beneficial utilization options were those that promoted solids stabilization through anaerobic digestion. Resource recovery was maximized through capture of biogas for sale to the local utility, reuse of heat energy for thermal drying, and production of a Class A biosolids product. Final recommendations indicated a diverse array of biosolids management options that would maximize CRD and provincial goals. Dried fuel product was determined to be particularly attractive, in part, because the carbon tax in British Columbia provided an economic incentive for industry. This market was the ultimate recommendation of the study. In addition, development of a topsoil blend and mine reclamation were recommended to diversify the biosolids program.Results of this analysis enabled CRD to make an informed decision about methods of production and biosolids utilization to maximize benefits. Regardless of the results of this analysis, the current plan is to produce a dried biosolids product that will be available as fuel for cement kiln or alternative energy production. Land-based biosolids recycling was not allowed in any form, even as a backup measure for the program. Details of the evaluation and further discussion of the decision-making process will be provided.