Al-Pac Biosolids Demonstration Project Soil Carbon Tracking

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City of Edmonton with Partners at EPCOR and the Edmonton Waste Management Centre of Excellence

Canadian municipalities have recognized the need to adopt environmentally responsible and sustainable practices to achieve goals in support of a healthier, more viable environment.  The City of Edmonton (City) has set environmental goals in terms of greenhouse gases, achievable through a series of targeted operational efficiencies and unrealized carbon storage options, to mitigate the City’s contribution to climate change.  In recognition of the potential that the City’s residuals could contribute to mitigating climate change through biomass production and soil carbon storage, SYLVIS began investigating opportunities to assess the potential of biosolids use in this novel option for the City and project partners.

In consultation with the City, EPCOR Water Services Inc (EPCOR), Alberta-Pacific Forest Industries (Al-Pac) and project stakeholders, SYLVIS developed a biosolids land application demonstration project to assess changes in site biomass productivity and soil carbon stores as a result of biosolids applications.  SYLVIS applied biosolids to 23 hectares of marginally productive agricultural land, authorized by Alberta Environment and Sustainable Resource Development (ESRD).  Following successful operational implementation of biosolids applications and establishment of a poplar plantation by Al-Pac, SYLVIS monitored the growth response and health of the trees and changes in soil carbon stores two years following applications.  Although there was no discernible biomass change in the poplar treatments as anticipated due to the low planting density and expected longer-term growth response, the soil carbon stores showed appreciable increases in the biosolids applied areas. 

Through a process of regulatory and stakeholder consultation and education, SYLVIS was able to implement an operational-scale project demonstrating the potential for the City to realize greater environmental benefit through the innovative use of City generated residuals such as biosolids.  Demonstrating incremental increases in soil carbon on biosolids-applied treatment areas provides a strong indication that this avenue of residuals management has the potential to assist the City in simultaneously achieving its residuals management and carbon reduction requirements.