NivaarExam PrepOfficial exam papers ↗

18-Env-A6 Solid Waste Engineering and Management · May 2013

Question 4 of 17: Disposal Options for Solid Waste

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

Notes on this paper

National Examination, May 2013 — 04-Env-A6 / 18-Env-A6, Solid Waste Engineering and Management. 3 hours duration, closed book, one letter-sized aid sheet permitted. All 17 questions constitute a complete paper (100 marks total).

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.

Check: several questions on this paper (Q1, Q13, Q14, Q17) supply an incomplete data set and explicitly invite the candidate to "make and state" assumptions. Every assumed value below is called out where it is introduced and is chosen from standard solid-waste-engineering practice; the governing METHOD, not the specific assumed number, is what the exam is testing.

Question 4: Disposal Options for Solid Waste (3 marks)

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.

Common disposal/management options include: sanitary landfilling (engineered, lined, with leachate and gas control); mass-burn or refuse-derived-fuel incineration with energy recovery (waste-to-energy); composting of the organic fraction to a stabilized soil amendment; materials recovery/recycling through a materials recovery facility (MRF); and anaerobic digestion of organics for biogas recovery. A defensible integrated program uses several of these together, prioritized by the waste-management hierarchy (reduce > reuse > recycle/compost > energy recovery > landfill), so that landfilling handles only the residual fraction the other options cannot economically divert. Which mix makes sense for a given community depends on waste composition, available markets for recovered material and energy, and the capital the municipality can commit.