• In Search of Better Conclusions – Part 2

  • In my last blog I wrote about ways to assist Environmental consultants and ESA practitioners in deriving and presenting better conclusions for Phase One ESA reports. This month I will discuss some methods for coming up with rational and defensible conclusions, especially on those ‘grey area’ ESA properties.   Some Sites are straight-forward and easier to discern conclusions and present recommendations. A ‘dirty site (i.e. documented spills, reports of contamination, ‘red-flag’ activities of concern like on-site dry cleaning operations or damaged and friable asbestos materials) obviously present actual and/or potential environmental concerns and further investigation (Phase Two ESA) should be recommended to confirm or refute the potential concerns and assess the environmental condition of the Site. Conversely, for a ‘greenfield’ property that has no identified environmental concerns on or off site, a Phase One ESA may be sufficient and there is likely no compelling reason to warrant a recommendation for a Phase Two ESA.

    But what about those in between sites? There may or may not have been a fuel tank 50 years ago and no definitive records are available? There’s an off-site gas station or dry cleaners in the Study Area, and it’s 100 m away, topographically cross-gradient with low-permeability till-like soils? For some properties there may be little to no data available to come to definitive conclusions – a rural property with no official records and the owner/operator has been dead for 20 years. These can be the types of Phase One ESA reports that require experience and professional judgement to be able to provide rational conclusions and defensible recommendations – some local knowledge helps too.

    Here, then are a few tips that I and my colleagues consider when we have these types of ESA sites.

    • Consider stakeholder objectives, end use of report, and regulatory requirements, sometimes your answer is mandated by regulation or prescribed by the clients comfort level and risk tolerance.
    • Are there one or more areas of concern on site – you likely need to go to a Phase Two; if the concerns are all off-site, it can be a bit trickier.
    • For off-site issues, you need to consider multiple factors. What is the nature and type of environmental concern? How toxic are the potential contaminants of concern? What is the distance from the subject site to the area(s) of concern? What is the topographic gradient? What is the inferred (and actual) groundwater flow direction? What are the nature, physical state(s) and fate/transport characteristics of the contaminant(s); are they mobile, do they sorb to soil, are they soluble in groundwater, can they migrate as a vapour, do they degrade to more toxic chemicals, are they persistent in the environment? Are there potentially sensitive receptors on-Site? Will current or future site operations be impacted by the identified concerns? The list goes on…
    • Sometimes, you just need some time to review and mull over all the data. If timing permits, I find ‘sleeping on it’ allows me to look at data more objectively and come to a reasonable conclusion.
    • Talk it over with colleagues, co-workers, mentors. There’s no substitute for group experience, and it’s possible one of your group has run across similar situations.
    • Think ‘worst case’ – if you were taken to court and sued over your report, could you defend your conclusions and recommendations in a court of law or to an expert peer reviewer?
    • Put yourself in a third party reviewer’s position – if you were retained to peer review the same report would you agree with the assessment, methodology, conclusions and recommendations? If not, why not? Consider what could or should have been done differently.
    • Once you have made your decisions, and you consider them to be both rational and defensible, stick to your decision and be clear and unequivocal in your presentation.

    These suggestions are by no means definitive or all inclusive, just something to think about the next time you are stuck with some difficult sites and report decisions.


    Bill Leedham, P. Geo., CESA

    Bill is the Head Instructor and Course Developer for the Associated Environmental Site Assessors of Canada (www.aesac.ca); and the founder and President of Down 2 Earth Environmental Services Inc. You can contact Bill at info@down2earthenvironmental.ca