18-Env-A1 Principles of Environmental Engineering · December 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exam — December 2015 — 04-Env-A1 Principles of Environmental Engineering (Closed Book, 3 hours; candidate-prepared 8½×11" double-sided aid sheet permitted). Any five (5) of the seven (7) problems below constitute a complete paper; all seven are solved here as a full study resource.
Reference texts: Davis & Cornwell, Introduction to Environmental Engineering, 6th ed.; Metcalf & Eddy, Wastewater Engineering: Treatment and Resource Recovery, 5th ed.; Mihelcic & Zimmerman, Environmental Engineering: Fundamentals, Sustainability, Design; MWH's Water Treatment: Principles and Design, 3rd ed.; Guidelines for Canadian Drinking Water Quality (Health Canada); Canadian Council of Ministers of the Environment (CCME) water quality guidelines; Canadian Environmental Protection Act (CEPA, 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.
The first fundamental problem is a competency–responsibility mismatch: a "limited experience" engineer has been assigned sole responsibility for daily inspection of safety-critical rotating machinery (bearings/belts) with no stated requirement for mentorship, peer review, or a senior engineer's sign-off, directly at odds with principle (a) — holding paramount public/worker safety requires that inspections of safety-critical systems be performed (or verified) by someone with the competence to correctly identify an emerging failure, not simply the person cheapest or most available to contract. The second fundamental problem is a weak, indirect escalation path: the engineer reports findings to an external ministry inspector who alone holds shutdown authority, meaning there is no described internal mechanism for the engineer to halt an unsafe line immediately when a hazard is discovered mid-shift; this delay between hazard discovery and corrective shutdown is itself a safety-welfare failure under principle (a), and it also weakens principle (c) since a "report" that only reaches an external body on some periodic or reactive basis, rather than triggering immediate internal action, does not adequately "appropriately report" or resolve an unresolved significant risk to workers.
A first improvement is pairing the contract engineer with a mentorship/peer-review structure — a licensed senior engineer reviews inspection findings and countersigns any assessment that a system is safe to continue operating, closing the competency gap without removing the contract engineer's day-to-day inspection role. A second improvement is granting the inspecting engineer (or an on-site safety authority working with them) an immediate internal stop-work authority for the specific line under inspection when a significant hazard is found, with the external ministry notified concurrently rather than being the sole authority capable of acting; this directly operationalizes principle (c)'s instruction that an engineer facing an unresolved significant public/worker risk may (and, functionally, should be empowered to) act rather than wait on an external process.
| Source | Contaminant | Control approach | Technical principle | Non-technical principle |
|---|---|---|---|---|
| Mobile: gasoline/diesel vehicle exhaust | NOx, CO, unburned hydrocarbons | Three-way catalytic converter / selective catalytic reduction (SCR) | Catalytic oxidation-reduction chemistry converts NOx/CO/HC to N2, CO2 and H2O before exhaust release | Vehicle emissions-inspection/maintenance regulation ensuring the installed control remains functional over the vehicle's life |
| Fixed: coal/oil-fired power plant stack | SO2 and particulate matter | Flue-gas desulfurization (wet scrubber) with electrostatic precipitator or baghouse | Alkaline slurry (limestone) absorption converts SO2 to gypsum; electrostatic charging/fabric filtration captures fine particulate | Cap-and-trade or emissions-intensity regulation that gives the facility an economic incentive to install and properly operate the scrubber |
| Fixed: industrial solvent/printing operation | Volatile organic compounds (VOCs) | Activated-carbon adsorption or thermal oxidation (see Problem 5(i)) | Adsorption onto high-surface-area carbon, or thermal combustion to CO2/H2O, both physically/chemically removing VOCs from the exhaust stream | Permit-based VOC emission limits and product-substitution incentives (low-VOC solvent/coating formulations) that reduce the load reaching the control device |
In every row, the technical principle removes or converts the contaminant at the point of emission, while the non-technical (regulatory/economic/behavioural) principle ensures the technical control is actually installed, maintained and kept effective over time — a pattern consistent with the ethical framework in part (i): technology alone does not protect public/worker/environmental welfare without an oversight mechanism that keeps it operating as designed.
