18-Env-A6 Solid Waste Engineering and Management · December 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.
This paper prints marks IN FRONT of the question number on every line (e.g. "5 1. What are the elements…", "4 16. All 29 questions are answered in full.
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) Public opposition and siting difficulty — strong community concern over air emissions and truck traffic makes new combustion facilities among the hardest waste facilities to permit and site. (2) High capital and air-pollution-control cost — meeting modern emission limits (particulate, acid gas, NOₓ, dioxins/furans, mercury) requires expensive scrubbers, baghouses and continuous emissions monitoring, driving up per-tonne cost relative to landfilling. (3) Ash residue management — bottom ash and (especially) fly ash can concentrate heavy metals and may require special handling or hazardous-waste disposal, and a disposal outlet must be secured before the facility can operate. (4) Guaranteed waste supply / competition with diversion — combustion facilities typically require long-term "put-or-pay" waste-supply contracts to be financially viable, which can create a perverse incentive that competes with source-reduction and recycling/diversion goals.
