18-Env-A6 Solid Waste Engineering and Management · May 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Tchobanoglous, Theisen & Vigil, Integrated Solid Waste Management: Engineering Principles and Management Issues; Vesilind, Worrell & Reinhart, Solid Waste Engineering; Davis & Cornwell, Introduction to Environmental Engineering (6th ed.); CCME, Guidance Document on Landfill Gas Management; Canadian Environmental Protection Act, 1999.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
1.1 Municipal solid waste management (MSWM) — the discipline concerned with the generation, on-site storage, collection, transfer/transport, processing and recovery, and final disposal of solid wastes arising from a municipality's residential, commercial and institutional sources, carried out in a manner consistent with the principles of public health, economics, engineering, conservation, aesthetics and other environmental considerations.
1.2 Sustainability — development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs (the Brundtland definition); applied to solid waste, it means balancing environmental protection (resource and land conservation, emissions), economic viability and social equity across a facility's full life, not just minimizing today's disposal cost.
1.3 Vermicomposting — a biological stabilization process in which specific earthworm species (e.g., Eisenia fetida, red wigglers) ingest and digest organic waste, and, together with the associated microbial community, convert it into a stabilized, nutrient-rich humus-like product (vermicast/worm castings), typically at ambient (mesophilic) temperature rather than the thermophilic temperatures of conventional composting.
1.4 Life-cycle analysis (LCA) — a systematic, cradle-to-grave accounting of the environmental burdens (energy use, emissions, resource consumption) of a product, process or waste-management option across every stage of its life — raw-material extraction, manufacture, use, and end-of-life management — used to compare alternatives (e.g., recycling vs. landfilling a given material) on a common basis.
1.5 Soil porosity — the fraction of a soil's total volume that is void (pore) space, $n = V_v/V_t$, available to hold air and water; it governs how much moisture a landfill cover or liner soil can store and how readily gas or leachate can migrate through it.
