A study was completed in 2018 to identify short-term biosolids management options, defined as those which could be fully implemented by the end of 2020, for the Timpanogos Special Service District (District) in American Fork, Utah. Historically, dewatered biosolids have been composted with green waste at the wastewater treatment facility to achieve both Class A pathogen reduction and meet vector attraction reduction. However, odors generated by the composting operations resulted in a settlement agreement that requires the District to cease all composting operations at the facility by the end of 2020. Short-term options evaluated included direct land application of the dewatered biosolids to local farm fields, offsite composting with green waste, and landfilling. Direct land application was determined to not be viable because of an excessive number of acres required and the need to incorporate biosolids into the soil to meet vector attraction reduction (VAR). Offsite composting could be viable but would be more expensive and logistically complex compared to landfilling. Landfilling was determined to be the most cost-effective and logistically simple, short-term option but contracts are not currently in place to haul and landfill all the District’s biosolids. If longer-term upgrades were made such that VAR could be met at the facility, then direct land application of the biosolids could likely compete favorably with landfilling, from both environmental and economic perspectives.
William J. Fasth
Evaluation of Short-Term Biosolids Management Options in Response to a Settlement Agreement
Authors: William J. Fasth, CPSS
2019 WEF/IWA Nutrient Removal Speciality Conference