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18-Env-B5 Industrial & Hazardous Waste Management · May 2016

Question 19 of 24: Municipal vs. Industrial (Cannery) vs. Hazardous Wastewater — Comparison Table

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

Notes on this paper

Reference texts: Nemerow & Dasgupta, Industrial and Hazardous Waste Treatment, 2nd ed.; Metcalf & Eddy, Wastewater Engineering: Treatment and Resource Recovery, 5th ed.; Davis & Cornwell, Introduction to Environmental Engineering, 6th ed.; LaGrega, Buckingham & Evans, Hazardous Waste Management, 2nd ed.; CCME, Guidelines for the Management of Biomedical Waste in Canada (1992); Canadian Environmental Protection Act (CEPA), 1999; Basel Convention on the Control of Transboundary Movements of Hazardous Wastes (1989); Canadian Nuclear Safety Commission (CNSC) regulations on radioactive waste; provincial hazardous waste regulations (e.g. BC's Environmental Management Act and Hazardous Waste Regulation).

Question 19: Municipal vs. Industrial (Cannery) vs. Hazardous Wastewater — Comparison Table (6 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.

CharacteristicMunicipal (domestic)Industrial — canneryHazardous
Flow patternSteady, predictable diurnal patternSeasonal/batch (harvest-driven), can be highly intermittentOften low-volume, batch or intermittent
BOD5 strength (assumed, mg/L)~200–300~1000–2000 (organic-rich)Highly variable; BOD often secondary to toxicity
TSS strength (assumed, mg/L)~200–250~500–1500 (peels, pulp)Variable; may include process solids/sludge
ToxicityLowLow to moderate (low if food-grade process only)High (heavy metals, solvents, cyanide, etc.)
BiodegradabilityHighly biodegradableHighly biodegradableOften poorly biodegradable / can inhibit biological treatment
Regulatory regimeMunicipal sewer-use bylawSewer-use bylaw + possible pretreatment orderFull hazardous-waste manifest/tracking regulation

How waste management would differ, and why:

  1. Municipal wastewater is managed by conventional biological secondary treatment (activated sludge or equivalent) at the municipal plant — no special pretreatment is needed because its strength and composition fall squarely within the plant's design basis.
  2. Cannery (industrial) wastewater is high-strength but readily biodegradable, so management focuses on flow/load equalization (to smooth the seasonal batch pattern) and often on-site screening/primary solids removal before discharge, either to the municipal plant (with a strength-based surcharge) or via a dedicated on-site biological treatment train if the seasonal load is too large for the municipal plant to absorb.
  3. Hazardous wastewater requires an entirely different management philosophy — because its constituents can be toxic to biological treatment or persistent in the environment, it cannot simply be diluted and biologically treated; it must be characterized, segregated, and routed to specific chemical/physical treatment, thermal destruction, or secure disposal, all under a regulated chain-of-custody manifest, rather than discharged to a conventional sewer at all.