Separate Collection of Yard Wastes: 18-Env-A6 Solid Waste Engineering and Management, December 2014, Q8

Question 8 of 29: Separate Collection of Yard Wastes

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

Notes on this paper

National Examination, December 2014 — 04-Env-A6 / 18-Env-A6, Solid Waste Engineering and Management. 3 hours duration, closed book, one non-communicating calculator, one letter-sized aid sheet (both sides) permitted. All 29 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; Canadian Environmental Protection Act, 1999.

Note on source parsing

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 8: Separate Collection of Yard Wastes (2 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.

Yard waste (grass, leaves, brush) has a high moisture content and is highly biodegradable, so mixing it with the dry recyclable stream contaminates paper and cardboard while mixing it with general refuse wastes its high value as clean compost feedstock and adds unnecessary biodegradable material (a methane source) to the landfill. Separate collection lets it be processed at a dedicated composting facility, recovering a beneficial soil amendment, reducing landfill airspace consumption and cutting long-term landfill gas generation, and it also allows collection schedules to flex with its strongly seasonal volume (spring/fall peaks).