Development of the Biosolids Emissions Assessment Model

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Canadian Council of Ministers of the Environment

In addition to using standard economic, social and environmental criteria, the greenhouse gas (GHG) footprint of biosolids management has become an important consideration in evaluating the feasibility of biosolids management options.  Few tools are available to complete this calculation, making the evaluation of GHG emissions due to biosolids management a challenge. 

Recognizing this gap with respect to GHG accounting and biosolids management, the Canadian Council of Ministers of the Environment (CCME) Biosolids Task Group retained SYLVIS, along with their project partners from the University of Washington, North East Biosolids and Residuals Association, and Northern Tilth, to develop the Biosolids Emissions Assessment Model (BEAM) for assessing GHG emissions from Canadian biosolids management programs and processes.  BEAM development consisted of a detailed literature review of current practices, emissions accounting protocols, accounting verification programs, sources of emissions and emission- and sequestration factors.  The project team developed GHG emission calculators for 12 management unit processes including biosolids storage, dewatering, composting, landfill disposal and incineration.  Net emissions are determined by subtracting GHG credits (sequestered carbon) from debits (sum of all emissions).  Results are provided for each unit process and for the overall management program on an absolute and unit (e.g tonnes of carbon dioxide equivalents per tonne of biosolids managed) basis.

Through our completion of the BEAM, SYLVIS, the CCME and our project partners are enabling biosolids generators to assess the impact of new and/or existing biosolids management programs, determine changes required to reduce GHG emissions and increase credits, and ultimately assist agencies in meeting their commitments to reduce GHG emissions.  SYLVIS has also worked with technology providers to develop BEAM modules specific to their systems.  The modular design of the BEAM allows for simple integration of new modules into the overall model.