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 three drivers act at different scales but share a common structure: each increases resource throughput and waste generation, and each has both a demand-side (reduce consumption) and a supply/infrastructure-side (treat or capture the impact) engineering response.
| Driver | Environmental impact | Environmental engineering solution |
|---|---|---|
| (i) Population growth | Increased municipal water demand and wastewater/solid-waste generation, straining treatment plant and landfill capacity | Water demand-management (low-flow fixtures, tiered/volumetric pricing) paired with phased treatment-plant and landfill-capacity expansion sized to population projections |
| Loss of agricultural and natural land to residential development, reducing groundwater recharge area and habitat | Urban growth boundaries and low-impact development (LID) standards (bioswales, permeable pavement) that preserve recharge and green infrastructure within the developed footprint | |
| (ii) Urban intensification | Increased impervious surface area, raising stormwater runoff volume/peak flow and combined-sewer overflow (CSO) frequency | Green/low-impact development (green roofs, rain gardens, permeable pavement) and stormwater detention/retention facilities sized for the intensified catchment |
| Urban heat island effect from concentrated pavement/building mass, raising summer cooling energy demand and heat-related health risk | Reflective/"cool" roofing and pavement materials, expanded urban tree canopy, and building-energy codes targeting passive cooling | |
| (iii) Increased energy use | Higher greenhouse-gas and criteria air-contaminant emissions from fossil-fuel-based generation and combustion | Shift to lower-carbon generation (hydro, wind, solar) and industrial/vehicle emissions controls (SCR, catalytic converters) |
| Greater thermal and water-consumption footprint of power generation (once-through or evaporative cooling water withdrawals) | Combined heat and power (cogeneration), demand-side energy-efficiency programs, and closed-loop/dry cooling systems to cut cooling-water withdrawal |
Read across the table, the pattern is consistent: population growth and urban intensification both increase the volume and concentration of waste streams a fixed piece of infrastructure must handle, so their engineering responses combine demand management with capacity/green infrastructure; increased energy use instead shifts the impact toward emissions and cooling-water demand, so its responses combine cleaner generation with efficiency and cooling-technology choices. A Canadian municipality planning a 25-year capital program should size treatment, stormwater and energy infrastructure against all three drivers together, since they typically grow in tandem.
