18-Env-B1 Environmental Assessment and Management Systems · December 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Mihelcic & Zimmerman, Environmental Engineering: Fundamentals, Sustainability, Design; Davis & Cornwell, Introduction to Environmental Engineering (6th ed.); ISO 14001:2015, Environmental Management Systems — Requirements with Guidance for Use; ISO 14040/14044, Life Cycle Assessment — Principles and Framework; Canadian Environmental Protection Act, 1999 (CEPA); Impact Assessment Act, 2019 (Canada); World Commission on Environment and Development, Our Common Future (the Brundtland Report), 1987.
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.
(i) Three key EIA issues for the transfer station. 1. Traffic and haul-route impacts on the surrounding community. Because the station serves a large municipality feeding a large landfill, the EIA must assess truck volume, routing and timing through residential streets, since haul-road impact is often the dominant nuisance issue for a transfer station even though it is not a direct emission. 2. Air quality, odour and vector (pest/bird) control. Putrescible waste handled in an enclosed or partially enclosed transfer building requires the EIA to assess odour dispersion to nearby receptors and the adequacy of enclosed tipping-floor ventilation/biofilter controls, plus vector-management measures. 3. Cumulative water-quality protection given the co-located landfill. Because the transfer station and landfill share the same site or watershed, the EIA must assess the combined (not just the transfer station's own) stormwater runoff and any leachate-adjacent seepage pathway to surface and groundwater, since a cumulative-impact assessment is required whenever two related facilities discharge to the same receiving environment.
(ii) Three CSO-reduction solutions. 1. Sewer separation and inflow/infiltration (I/I) reduction. Removing stormwater connections (downspouts, sump pumps) from the sanitary system and rehabilitating cracked pipe/manholes (cured-in-place lining) reduces the wet-weather flow volume that triggers an overflow in the first place. 2. Real-time control and increased in-system storage. Instrumented gates and pumps at the pumping station, coordinated with upstream storage in oversized interceptor pipes, hold back wet-weather flow and release it to the treatment plant once capacity is available, rather than overflowing untreated. 3. Dedicated offline storage or high-rate CSO treatment at the pumping station. A storage/detention tank (or a high-rate physical-chemical treatment train) captures and later treats the peak flow that the pumping station cannot convey during a storm, directly reducing the untreated volume discharged.
(iii) Technical solution to reduce industrial VOC discharge from multiple single sources near a residential community. Fit each source's exhaust with a combination of a carbon-adsorption or thermal/catalytic oxidation unit sized to that source's specific VOC load and stream characteristics, rather than relying on dilution or stack-height dispersion alone: adsorption (activated-carbon beds, regenerated by steam or hot-gas desorption) is well suited to lower-concentration, intermittent sources, while catalytic oxidation is more economical for continuous, higher-concentration streams. Pairing the abatement equipment with continuous fenceline VOC monitoring around the industrial park gives both real-time verification that emissions are controlled and an early-warning system protective of the adjacent residential community, addressing the exposure pathway directly rather than only the source.
