Lehigh Villeneuve Biosolids Demonstration Project
The City of Edmonton (City) and EPCOR Water Services (EPCOR) have long-standing programs of biosolids management that include spreading of liquid biosolids to agricultural land and composting with municipal solid waste and wood chips. The City and EPCOR desired more diversity in their biosolids program, and sought to address an annual accumulation of biosolids in the Clover Bar storage lagoons. SYLVIS investigated new land application options for biosolids produced in the Edmonton region, identifying mine reclamation, marginal land improvement and biomass production as potential options to augment current beneficial uses.
The Lehigh Villeneuve aggregate mine was selected as a project partner in the biosolids demonstration program. A similar aggregate mine operated by Lehigh in Sechelt, BC has received biosolids as part of ongoing reclamation for more than a decade under the direction of SYLVIS, providing a strong case study in biosolids use for mine reclamation. SYLVIS developed an operational-scale biosolids demonstration project for a portion of land on the Lehigh Villeneuve aggregate mine to determine the effect of biosolids on crop production, soil fertility, and surface water quality. Biosolids were applied as authorized by Alberta Environment and Sustainable Resource Development, in consultation with Lehigh Villeneuve, the City, EPCOR, and project stakeholders. The site was monitored for two years following applications to assess changes in productivity and soil quality.
Measures of crop quality and productivity indicated that biosolids applications substantially increased the yield of a cereal crop grown on the site following applications. Nitrate, phosphorus, and sulphate concentrations in the soil beneficially increased with increasing application rate, as anticipated. The operational and research success of the Lehigh Villeneuve project demonstrates the capacity of degraded sites to form a component of the City’s biosolids management program, adding diversity and contingency to the current options.