Providing Expert Opinion to Support Environmental Litigation Joel van Popta April 27, 2018
Outline Purpose of Opinion Evidence Duty of an Expert Perception of Bias Maintaining Objectivity Facts / Evidence Case Study Summary Questions?
Purpose of Opinion Evidence
Purpose of Opinion Evidence Explain complexity Do not unnecessarily increase the complexity Work within your area of expertise Scope of work outlined in retainer letter
Duty of an Expert
Duty of an Expert Form 53 (Acknowledgment of Expert’s Duty) I acknowledge that it is my duty to provide evidence in relation to this proceeding as follows: to provide opinion evidence that is fair, objective and non-partisan; to provide opinion evidence that is related only to matters that are within my area of expertise; and to provide such additional assistance as the court may reasonably require, to determine a matter in issue. I acknowledge that the duty referred to above prevails over any obligation which I may owe to any party by whom or on whose behalf I am engaged.
Duty of an Expert Civil action, not criminal Making conclusions / judgements on the balance of probabilities, not “beyond all reasonable doubt” What is the most plausible and reasonable outcome from a certain set of circumstances?
Perception of Bias
Perception of Bias Bias: prejudice in favor of or against one thing, person, or group compared with another, usually in a way considered to be unfair Do not become overly sympathetic to your client Association bias Not about ‘winning’
Maintaining Objectivity
Maintaining Objectivity Difficult to maintain if involved in a file for a long time. Remain dispassionate when responding to a rebuttal report Bounce ideas off colleagues Be wary of clients pushing for a certain outcome You are not an advocate, that is the lawyer’s job
Facts / Evidence
Facts / Evidence Provide an opinion based on accurate, discernable facts Don’t guess or speculate Provide explanations based on facts that clearly articulate the most persuasive and plausible explanation If using assumptions, are they reasonable?
Opinion of Contaminant Migration Case Study Opinion of Contaminant Migration
Background Residential fuel oil release AST located in basement Gravel floor over bedrock Basement recessed into bedrock Close proximity to neighbours Slow leak over a number of months 100 L to 400 L release volume
Stratigraphy / Hydrogeology +/- 1 m overburden – silty sand Weathered limestone bedrock to 4 m. Shale seams within weathered limestone interval Competent limestone bedrock beyond Shallow groundwater in weathered bedrock
Scope of Work Stantec was asked to review assessment and remediation reports prepared by others and respond to the opinion of another consultant associated with the following: possibility of historical impacts multiple sources of hydrocarbon size of the contaminant plume
Facts / Evidence Volume of 100 L to 400 L fuel oil over a period of up to one year Shallow groundwater approximately 0.5 m below release point Groundwater elevation higher under house than neighbouring properties Dominant flow path within weathered bedrock Liquid product and highest dissolved concentrations near loss location No forensics on liquid product or review of chromatograms
Conclusions No evidence in the reporting record of a forensic evaluation that assessed either the degree of contaminant weathering or assessed certain contaminant characteristics in different parts of the plume that could address whether multiple sources existed. Groundwater monitoring and sampling by others demonstrated that free-phase petroleum hydrocarbon (PHC) was present near the point of loss, and concentrations of PHC parameters in groundwater decreased away from the point of loss No evidence of multiple PHC sources Migration away from point of loss was through fractured bedrock. The size of the plume is not unreasonable.
Summary
Summary Explain Complexity Duty to the Court Remain unbiased and maintain objectivity throughout the file Articulate a clear fact-based opinion that supports the most plausible explanation
Questions?