16-Civ-A3 Elementary Environmental Engineering · December 2017
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. National Exams, December 2017 — 16-Civ-A3 Elementary Environmental Engineering. Three hours; closed book with one candidate-prepared 8½ × 11 double-sided aid sheet; approved Casio or Sharp calculator only. Seven problems are printed, each worth 20 marks, and any five constitute a complete paper (maximum 100 marks). All seven are solved here, because the set is intended as a study resource rather than an exam script. Section marks are shown in brackets at the left margin of each question and are reproduced from the final-page Marking Scheme.
Reference texts.
Canadian context. Answers use the Canadian regulatory frame: the Guidelines for Canadian Drinking Water Quality (GCDWQ) and Canadian Environmental Quality Guidelines (CCME), provincial water and wastewater regulations, the federal Impact Assessment Act / BC Environmental Assessment Act, and the Engineers Canada / EGBC code of ethics whose canons appear in Problem 2(iii).
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.
| Type | Control | How it works | Advantage | Limitation |
|---|---|---|---|---|
| Technical | On-vehicle after-treatment: diesel particulate filter (DPF) + selective catalytic reduction (SCR) | The DPF physically traps PM10 soot; SCR injects urea so a catalyst reduces NOx to N2 and water | Very high removal (DPF > 90% PM, SCR 70–90% NOx) directly at the tailpipe | Adds cost and maintenance; needs low-sulphur fuel and urea supply; can be tampered with or degrade if unmaintained |
| Non-technical | Policy/planning: emission standards + transit and mode-shift measures (low-emission zones, transit investment) | Regulations force cleaner fleets while planning reduces vehicle-kilometres travelled | Cuts emissions fleet-wide and at source by reducing traffic, not just per-vehicle | Slow to take effect (fleet turnover, infrastructure lead time); requires public acceptance and enforcement |
With capacity for only 10 more years at the current rate, extending the site to 20 years requires roughly halving the mass sent to disposal — a 50% diversion target. The plan follows the waste-management hierarchy (reduce, reuse, recycle, recover, then dispose) and combines engineered diversion facilities with the programs and policies that feed them.
Technical strategies:
Non-technical strategies:
Together these achieve source reduction plus two major engineered diversion routes, which is what makes a durable 50% reduction — and therefore the 20-year site life — realistic.
