Risk Assessments

Risk Assessments


A Common Reason Risk Assessments Are Rejected and a Potential Solution

Early morning discussions at a technical conference are often fruitful. While talking to a couple of consultants who spend their days conducting risk assessments (RAs), we gained some insights into the RA process. The Ministry of Environment (MOE) recently changed their RA review process to involve the Record of Site Condition (RSC) branch in the technical review of RAs. The reason: RAs were being commonly turned back at the RSC stage for further review due to incomplete site delineation, and in particular due to incomplete vertical delineation. The MOE is now requiring full and proper delineation at the time of the RA, in an effort to close off potential issues before reaching the RSC stage.

This message was repeated throughout the day at the Canadian Brownfields Network’s (CBN) Event in Toronto – Brownfields Redevelopment: Policy, Planning and Practice.

Two environmental lawyers – Janet Bobechko, (Partner, Environmental Law Specialist, Blaney McMurtry LLP) and Alexandria Pike, (Partner, Davies Ward Phillips & Vineberg LLP) mentioned this challenge of improper delineation in their respective panel presentations.

We have since spoken to several more Qualified Persons (QPRA) and found that as many as 50% of RAs are rejected due to improper delineation. Although RAs may be rejected for a variety of reasons, the requirement for additional delineation costs clients the most, as it requires re-mobilizing to the site for more drilling and sampling. In one case for a site in the GTA, these additional costs were estimated at $100,000.

The presence of an apparent confining layer may also not be enough to rule out having to assess for deeper impacts. In several cases shared with us, it was clear the MOE is asking for hard data to confirm assumptions of vertical delineation – even where there is ample evidence of thick, continuous, low permeable, confining silty clay till units.

To help tackle the challenges of delineation, many QPs are adopting the application of high resolution characterization tools such as Laser Induced Fluorescence (LIF) and Membrane Interface Probe (MIP) tooling.

As a technical recap, these are field screening tools that provide real time data on the presence and degree of in-situ contamination. The tools are advanced into the subsurface using direct push rigs and rods.

The LIF technology efficiently delineates free phase petroleum, oil, and lubricant (POL) contaminants in the subsurface.

The MIP is employed for delineation of dissolved phase VOC contaminants.

It’s clear this technology is receiving much wider acceptance in recent years. For example, Defense Construction Canada is incorporating the LIF and MIP into both its delineation and remediation tracking programs (e.g. Canadian Forces Base 5 Wing Goose Bay and at multiple military bases in Alberta); the Ontario Ministry of Transportation used the LIF and MIP to define the location of free phase and dissolved phase impacts to direct a large northern Ontario remediation program; multi-national oil companies are using high resolution characterization to gain a better understanding of the subsurface at their sites; other adopters of the technology include the MOE itself, the Toronto Transit Commission (TTC), and our national rail companies.

This trend is also evident on the conference circuit. At last year’s Real Property Institute of Canada (RPIC) Federal Contaminated Sites National Workshop there was only one presentation on high resolution characterization; this year five separate talks highlighted the use of these technologies. Similarly, at Battelle’s 2014 International Conference on Remediation of Chlorinated and Recalcitrant Compounds, there were many more talks and poster presentations centered on high resolution characterization this year compared to past sessions.

Delineation work by its nature is an iterative process. An initial data set must be gathered in order to make decisions about additional data requirements. With the ability of the LIF and MIP to report back data in real time, consultants are immediately provided with knowledge, and on-site decisions can be made. The data may indicate where a clean boundary has been reached or that the extent of the drilling program should be extended in a particular direction. This can all be done without remobilizing to the Site.

Perhaps most powerful, is the ability of the tools to direct vertical delineation. Consider, the MIP has a vertical resolution if 30 cm, while the LIF has a vertical resolution of 1 cm. The 3-D mapping that can be done after the data is collected is a very powerful visual tool to show regulators and land owners alike.

These tools lend a tremendous ability to incorporate flexibility into a drilling program. They provide the ability to intelligently adapt your drilling program; to make sound decisions ‘on the fly’ about where to collect the next soil sample, place the next monitoring well or whether to drill deeper to complete the vertical delineation of contaminants.

It may also be critical to the RA process to understand where the bottom or the top of the contaminated zone is, right down to the last centimeter.

These may just be the tools you need to ensure your next RA is not returned with a request for further delineation work.

Until next time…Excellence is Your Choice!