18-Env-B4 Site Assessment and Remediation · December 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams; December 2015 — 04-Env-B4 / Site Assessment and Remediation. 3 hours duration; open-book exam (any non-communicating calculator permitted). The paper is split into Section A (five questions, candidates asked to answer three) and Section B (three questions, candidates asked to answer two), each question worth 20 marks. All eight questions are solved below for completeness.
Reference texts. Suthersan & Payne, Remediation Engineering: Design Concepts (CRC Press); Freeze & Cherry, Groundwater; Schwarzenbach, Gschwend & Imboden, Environmental Organic Chemistry; Davis & Cornwell, Introduction to Environmental Engineering (6th ed.); Leeson & Hinchee (1997), Soil Bioventing: Principles and Practice (AFCEE); ASTM E1527 Standard Practice for Phase I Environmental Site Assessments and ASTM E1903 Standard Practice for Phase II ESA; American Petroleum Institute (API) publications on UST release modelling; Ontario Reg. 153/04 under the Environmental Protection Act (Record of Site Condition regime); BC Environmental Management Act / Contaminated Sites Regulation.
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.
A central-core Southern Ontario location changes the economics of the decision relative to a rural or greenfield alternative: land is scarce and expensive downtown, existing municipal infrastructure (water, sewer, transit, roads) is already in place, and Ontario has a specific regulatory and financial-incentive framework (Ontario Reg. 153/04 Records of Site Condition, municipal Brownfields Community Improvement Plans / tax increment financing) purpose-built to encourage exactly this kind of redevelopment.
Advantages. Reuses existing infrastructure and transit access instead of extending services to a greenfield site at the urban edge, which is both cheaper for the municipality and reduces sprawl and the associated loss of agricultural/natural land; central-core land commands a much higher redevelopment value (residential/mixed-use) than the same remediated area would in a peripheral location, often making the remediation cost economically justified where it would not be on a low-value rural parcel; municipal financial tools (tax increment grants, development-charge exemptions, provincial brownfields tax incentives) are specifically available to offset remediation cost; removing an active contamination source improves neighbourhood environmental quality and public health, and returns an idle, often blighted property to productive use and the tax roll; and a Record of Site Condition, once filed, provides the developer and future owners a defensible liability shield.
Disadvantages. Remediation cost is frequently uncertain until intrusive investigation is complete, creating project financing risk (a lender or buyer may require the RSC before committing capital, delaying the transaction); central-core sites are often small and constrained by adjacent occupied buildings, utilities, and traffic, which limits remedial method choice (large excavation equipment and haul routes may not fit) and can force more expensive in-situ or contained-excavation approaches; older industrial core sites often carry legacy contaminants (coal tar, chlorinated solvents, PCBs, asbestos in structures) that are expensive to characterize and remediate fully; construction activity and truck traffic in a dense downtown setting cause greater community disruption (noise, dust, road closures) than the same work would in a rural setting; and there is long-term stigma/liability risk even after remediation — residual contamination discovered post-development, or a failure of an engineered control (e.g., a vapour barrier), exposes the developer to remediation-in-perpetuity obligations under the RSC regime.
| Category | Advantage | Disadvantage |
|---|---|---|
| Location value | High redevelopment value justifies remediation cost | Site constraints (small footprint, adjacent buildings) limit method choice |
| Infrastructure | Reuses existing water/sewer/transit; reduces sprawl | Utility conflicts complicate intrusive work |
| Financial/regulatory | Ontario Reg. 153/04 RSC liability shield; municipal incentives | Cost uncertainty until investigation complete delays financing |
| Community | Removes blight; improves public health; returns property to tax roll | Construction disruption (traffic, dust, noise) in a dense core |