Risk assessments (RA) are one of the main tools for managing contaminated sites. Managers of federal contaminated sites frequently use risk assessments to evaluate potential risks caused by contamination to ecological (ERA) and/or to human health (HHRA) and to support risk management measures. Significant guidance is available to custodians on conducting ERAs and/or HHRAs on federal sites from FCSAP and its Expert Support partners. However, in Canada, other approaches than those from FCSAP are used to complete ERAs and HHRAs such as provincial and regional approaches. Approaches from other Canadian jurisdictions may have similarities and/or differences from the federal approach. As practitioners or reviewers of RAs, awareness of these difference in RAs can expand our expertise and may bring very useful options in our day-to-day work. As managers of federal sites, we face challenges such as contamination migrating from federal sites to sites under provincial jurisdiction, divesting federal sites to the provincial or municipal stakeholders , or simply the fact that federal sites are almost always neighbor of provincial sites. Knowing that, this presentation will provide some insights on similarities and differences between federal and provincial approaches when conduction RAs, and hopefully initiate discussion as to what does it mean for our day-to-day work.

Nathalie Gaudreau, Public Services and Procurement Canada

Arcadis Canada Inc. (Arcadis) was retained by Public Services and Procurement Canada (PSPC) on behalf of the Department of National Defence (DND) to conduct a human health risk assessment and ecological risk assessment (HHERA) at the Petawawa Research Forest dump site #1 (the site) located in Garrison Petawawa in Petawawa, Ontario. In addition to the dump site, the area surrounding the dump site, identified and referred to as the exposure area, was also considered as the risk assessment (RA) site. The site included mature coniferous forest and a large meadow marsh wetland area as well as a creek flowing through the wetland and a small open water area. A supplemental site investigation (SSI) was completed at the site and surrounding area in support of the RA and site closure. After secondary screening, no contaminants of potential concern (COPCs) were retained for quantitative assessment of human health.

Ecological receptors evaluated by the RA comprised both terrestrial and aquatic receptors including plants, invertebrates, birds, amphibians/reptiles, and mammals. Off-site receptors considered were the same as on-site receptors. Ecological exposure pathways evaluated by component screening included direct soil contact, soil and food ingestion, protection of freshwater aquatic life (from soil leaching to groundwater and from groundwater discharging to surface water), root uptake of groundwater, freshwater life (from groundwater discharging to surface water), sediment contact and food chain modelling, surface water freshwater life and food chain modelling. Food chain modelling included valued ecosystem receptors from herbivorous, omnivorous, insectivorous and carnivorous guilds for both terrestrial (i.e., meadow vole, masked shrew, deer mouse, white-tailed deer, snowshoe hare, black bear, red fox, ruffed grouse, American robin, barn swallow and red-tailed hawk) and aquatic (i.e., muskrat, moose, mink, mallard duck, spotted sandpiper and bald eagle) environments.

The ERA employed multiple lines of evidence following the Federal Contaminated Sites Action Plan (FCSAP) Weight of Evidence approach which included a benthic invertebrate community assessment, species-at-risk surveys, habitat assessment, phytotoxicity assessment and site specific acute and chronic toxicity testing to aid in the interpretation of chemical data. Based on the results of the RA, unacceptable risks to human and ecological receptors resulting from exposure to site soils, groundwater, sediment and surface water were not anticipated and the site was closed by DND.

Barbara Hard, Discipline Lead for Natural Sciences, Arcadis Canada Inc.
Barbara Hard is the Arcadis Discipline Lead for Natural Sciences in Canada. She is a Professional Biologist (P.Biol., R.P.Bio.) with over 27 years of experience in ecological risk assessment, environmental assessment, natural resources and permitting. Her experience includes terrestrial and aquatic biology, wetland evaluation, species-at-risk surveys and compensation plans, ecological risk assessment, phytoremediation, permit applications, public consultation processes and project management. She has completed natural environment projects across Canada for mining and aggregate clients, energy companies, oil and gas clients, municipalities, provincial and federal clients. Barbara is a hands-on biologist with extensive field work experience.

Public Services and Procurement Canada (PSPC) is the federal custodian of a portfolio of sites associated with the construction and maintenance of the former Alaska Highway alignment in the 1940s, including now abandoned, historical maintenance camps, townsites, and quarry sites. These sites were originally operated by the US military, with contaminant sources such as maintenance garages, fuel storage facilities and waste disposal. These abandoned sites have naturally revegetated over time, which has increased the on-site habitat for ecological receptors and forage and hunting areas that may be used by the public and First Nations. PSPC is now addressing these sites using risk assessment, either alone or in combination with targeted physical remediation efforts. Golder Associates Ltd. (Golder) has applied an iterative risk assessment approach to evaluate several of these sites with the ultimate goal of achieving site closure in a cost-efficient manner. Where sites cannot be screened out using simple or straightforward risk assessment approaches, an iterative approach allows for an increased level of complexity to be applied only to those pathways that require further detailed evaluations.

A case study will be presented that describes the iterative risk assessment approach conducted for one site on the track towards site closure. The site is a former quarry and abandoned vehicle dump located on a remote plateau along the former Alaska Highway alignment, in northeastern British Columbia, which had undergone several rounds of intrusive investigations, National Classification System for Contaminated Sites (NCSCS) scoring updates and geophysical studies. The risk assessment was conducted in three iterations. 1) The initial risk assessment (first iteration) was based on the available data from site investigations (including a preliminary aquatic risk assessment based on limited data from on-site wetlands), and was used to identify whether any exposure pathways were associated with potential risk to human or ecological receptors, thereby warranting further evaluation. 2) The second iteration focused on refining risks for the aquatic component following the preliminary aquatic risk assessment. The collection of site-specific data across multiple lines-of-evidence, including analytical chemistry, toxicity testing and benthic community analysis, was compiled into a weight-of-evidence-based (WOE-based) detailed aquatic risk assessment. 3) A final iteration was conducted to refine risk estimates and reduce uncertainties for terrestrial ecological receptors, which were primarily driven by small bird and mammal invertivores, evaluated in a food chain model.

The case study will focus on the phases of sequential refinement conducted to increase the realism of risk estimates in the aquatic WOE and terrestrial wildlife assessments. Technical considerations and challenges will be discussed including the benefits and pitfalls of collecting site-specific dietary items (including country foods, leaves and invertebrates). Refining risks through the collection and analysis of site-specific samples is typically preferred to the use of literature bioaccumulation models, which are highly conservative and often over-estimate risk. However, as for the case study presented, the collection of a variety of dietary items can result in new challenges and reveal additional site-specific complexity.

Jennifer Cook, Environmental Scientist, Golder Associates Ltd.
Jennifer Cook is an Environmental Scientist in Golder Associate Ltd.’s Vancouver office. Her work focuses mainly on conducting human health and ecological risk assessments for sites across British Columbia, under both federal and provincial regulatory frameworks. Her background in contaminated sites investigation and remediation, and prior pre-clinical laboratory research experience, ensure that investigation and data quality knowledge are considered in her risk assessments. Her projects have included a variety of industrial and commercial properties, former mine sites, remote sites impacted by historical activities, and First Nations lands.

This presentation will review the history of risk assessment, with a focus on British Columbia and Federal Contaminated Sites Action Plan (FCSAP) regimes, in the context of contaminated sites. In the beginning there was the Fisheries Act, the 96-hour acute fish toxicity test and “environmental impact assessments”. What were the regulatory and technical drivers that created our risk assessment practice? How has the past shaped our current regimes? What are our current challenges and what could/should/will the future bring? This presentation combines historical review and opinions gathered from risk assessment practitioners and regulators. The presentation will conclude with suggestions for how risk assessment/risk management can best support remediation of contaminated sites.

Alena Fikart, Environmental Scientist, Azimuth Consulting Group
Alena Fikart is an environmental scientist with 18 years of professional experience. She delivers projects with ecological risk assessment (e.g., food chain modeling, novel approaches, guidance development and contaminated sites) and environmental monitoring. Alena manages these projects for both government (federal and BC provincial) and industrial clients (mining, pulp and paper, port facilities). She contributed to the development of federal ecological risk assessment guidance for Environment Canada (published by FCSAP) and a risk-ranking methodology for abandoned mine sites in BC.

Victoria and Esquimalt Harbours are alike and different in many ways. Both are working harbours on Vancouver Island with historical contamination requiring action through Federal Contaminated Sites Action Plan (FCSAP). They have different custodians (Transport Canada and the Department of National Defence, respectively), various historical and ongoing site uses, and are at different steps in the 10-step process (step 7 and 9, respectively). One unique similarity is that recent sampling at both sites identified a dramatic difference in metals concentrations among clam species, which required additional investigations of potential causes and impacts on remedy decisions.

Macoma clams (Macoma spp.) were collected from Esquimalt Harbour and a reference site outside the harbour in 2019 to verify elevated copper concentrations in historical samples and identify potential sources. All 2019 clam samples collected inside the harbour and two of three reference samples had copper concentrations above the screening level for no effect on invertebrate reproduction, consistent with previous-year concentrations. Co-located sediment copper concentrations were below the probable effect levels (PEL) and surface water copper concentrations do not show a strong correlation with the areas with elevated Macoma concentrations.

Victoria Harbour also conducted a tissue sampling program in 2019 which included extensive testing of pollutant levels in clam tissue over several years at nearly two dozen locations and across a broad range of species. At most locations, between two and five species were tested, allowing differences in metals bioaccumulation among species to be quantified. Measured lead levels in Macoma were consistently an order of magnitude higher than in other clam species collected at the same locations and under the same environmental conditions. Concentrations of lead in Macoma clams exceeded the human health hazard quotient (HQ) and are not coincident with elevated levels of sediment lead contamination.

A review of both sets of data indicate a significant difference in the uptake of metals in Macoma clams in comparison with other intertidal clam species. In the scientific literature, Macoma clams are a commonly used bioindicator of benthic exposure to metals contamination. Research shows the Macoma genera of clam has an ability to bioaccumulate up to 50x nearby sediment concentrations of metals under certain conditions (Hendożko et al. 2010; Bryan and Langston 1992).

Following a summary of the data collected in each harbour, this presentation will discuss how these results are being incorporated into ecological risk estimates and source control investigations for Esquimalt Harbour and use of site-specific information regarding First Nation-preferred clam species in human health risk assessments for Victoria Harbour. Additionally, the presentation will use these results to emphasize the importance of species selection in development of investigations for risk estimation and biomonitoring efforts.

Amy Corp, Managing Scientist, Anchor QEA, LLC
Amy Corp is a Managing Scientist at Anchor QEA, LLC, and has more than 14 years of experience in the environmental science and chemistry fields. Amy specializes in all aspects of contaminated site remediation, including conceptual site model development, designing and performing site investigations, conducting remedial options analysis, and providing federal project management reporting. She has played a key role in several large-scale cleanups including planning and implementation for sites within working harbours.

Human health risk assessment (HHRA) of methylmercury in seafood presents challenges to risk assessors and regulatory agencies in Canada and elsewhere. Seafood represents one of the key sources of methylmercury for many Canadians; however, agencies around the world recognize seafood as an excellent source of nutrition and recommend it as part of a healthy diet. Thus, there remains the concern that we do not want fish consumption recommendations to do more harm than good. In this presentation, recent scientific developments and challenges in the HHRA of methylmercury will be discussed.

One of the most intriguing aspects of HHRA of methylmercury is associated with the toxicological/epidemiological dataset. Most of our information has arisen from contrasting results of studies in the Faroe Islands and the Seychelles Islands. In the Faroe Islands, clear neurodevelopment effects were observed in children born to mothers with elevated methylmercury blood/hair concentrations and these effects continue to be measurable in the study participants who are now young adults. In the Seychelles Islands, these effects were largely not seen despite the mothers having similarly elevated methylmercury concentrations in blood and hair. Although there have been attempts to explain why the effects were largely only seen in the Faroe Islands (the most common thesis is that the key source of methylmercury in Faroe Island was whale meat which is low in selenium while the Seychelles Island source was marine fish that was much higher in selenium), major regulatory agencies have not yet used these arguments in modifying fish consumption recommendations and certain academic researchers have noted concerns in the theories. Nevertheless, it remains a topic of ongoing debate in the literature and at scientific conferences. Another important aspect of the HHRA of methylmercury is the potential importance of reduced bioavailability in certain types of seafood. Although there is currently no regulatory validated method for use of bioaccessibility results in the HHRA of methylmercury, the scientific literature has provided some very intriguing results which could have enormous importance. Specifically, it is possible that certain seafood and types of cooking may alter the bioaccessibility of methylmercury.

In expressing fish consumption recommendations in number of meals per month, exposure amortization on a monthly basis seems acceptable to many regulatory agencies. Nevertheless, there are other considerations in the toxicokinetics of methylmercury can be vital to proper completion of a HHRA of methylmercury. With a relatively long half-life in blood, methylmercury can take quite some time to reach steady-state concentrations that are the basis of the toxicity reference value; however, it is also removed rather slowly from the blood and thus, this needs to be considered (especially when providing advice to women of childbearing age). These considerations can have important implications in the interpretation and use of food survey information when persons consume proportionally more seafood on a seasonal basis. Thus, it remains important that risk assessors consider the time of year that the greatest amount of seafood consumption is occurring and the associated toxicokinetics when estimating risks.

Overall, there continues to be scientific advancements in the HHRA of methylmercury in seafood. Risk assessors and regulatory agencies should continue to monitor the science as a number of regulatory agencies and numerous academics continue to study the various issues.

Ross Wilson, Wilson Scientific
Ross Wilson is a board-certified toxicologist with 30 years of experience in human health risk assessment. In 2005, Ross was appointed by BC Ministry of Environment as an Approved Professional in risk assessment and from 2012 to 2016 served on the Board of Directors of the Society of Contaminated Sites Approved Professionals (CSAP) of British Columbia. In 2014, Ross was appointed to the editorial board of the international journal Human and Ecological Risk Assessment (HERA).

In the case of expertise in soil, dust and sediment ingestion rates, he has assisted Health Canada on several projects over the last ten years. With Health Canada as co-authors, he published Wilson et al. (2013: Revisiting Dust and Soil Ingestion Rates based on Hand-to-Mouth Transfer) which is cited as a key paper in the US Environmental Protection Agency Exposure Factors Handbook chapter 5 update. He also published a paper on sediment ingestion rates in 2015 (with Health Canada as co-authors) and dust ingestion rates in units of m2/day in 2016. In the case of evaluation of methylmercury in seafood, Ross has been involved in several projects over his career. Since 2011, he has attended all meetings of the International Conference on Mercury as a Global Pollutant (ICMGP).

As part of the risk management of outlying areas of Esquimalt Harbour, British Columbia, an evaluation of any remaining sources of risk to human health and the environment is ongoing. One area of interest includes Plumper Bay, where multiple studies have been conducted to assess contaminant concentrations in sediment and bivalve tissue and the area of interest resides within the First Nations waterlot.

A harbour-wide human health risk assessment (HHRA) was finalized in 2017 and characterized risks to consumers of seafood from consumption of crab (muscle and hepatopancreas), clam, mussel, lingcod, rock fish, shrimp and sea urchin. In recent years, fish, crab, mussel, oyster and clam samples were collected from Plumper Bay to assess trends (including any impact of harbour-wide dredging) and current exposure levels. Based on the results of this recent sampling, supplemental non-bivalve tissue sampling was identified to support an overall picture of remaining human health risk specific to Plumper Bay.

Sea urchin and chiton were identified for the expanded tissue sampling due to their importance to the First Nations and site fidelity which would provide information specific to Plumper Bay, in comparison to more mobile species such as crabs and fish. Additionally, chitons are mollusks that generally have a limited capability to metabolize organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), and therefore may bioaccumulate contaminants from nearby historical contamination and would act as a conservative measure of tissue concentrations.

This presentation will review the rationale for collection of chiton and sea urchin samples, methodology for collection and tissue processing, and data analysis including how the tissue concentrations from these expanded species can be quickly reviewed to provide an assessment of risk without conducting a full HHRA.

Amy Corp, Managing Scientist, Anchor QEA, LLC
Amy Corp is a Managing Scientist at Anchor QEA, LLC, and has more than 14 years of experience in the environmental science and chemistry fields. Amy specializes in all aspects of contaminated site remediation, including conceptual site model development, designing and performing site investigations, conducting remedial options analysis, and providing federal project management reporting. She has played a key role in several large-scale cleanups including planning and implementation for sites within working harbours.

Fish are an important receptor group ecologically and socioeconomically and are often of key interest in aquatic ecological risk assessments (ERAs) at contaminated sites. Toxicity reference values (TRVs) are one tool used in ERAs as benchmarks of effects against which environmental exposure to contaminants can be compared. This project builds on existing ERA guidance from the Canadian Federal Contaminated Sites Action Plan (FCSAP) for selecting and developing site-specific TRVs (Module 2), and for recommended default TRVs for protection of avian and mammalian wildlife (Module 7). In contrast to wildlife TRVs, which are readily available from commonly referenced sources, standard compilations of TRVs for the protection of fish are not available to our knowledge. Therefore, aquatic ERAs commonly rely on (1) more generic ‘benchmarks’ such as aquatic life guidelines, which are not specific to fish; and, (2) more involved field-based lines of evidence (e.g., toxicity testing, population surveys). This project aims to identify fish-specific TRVs that would be suitable default values for use at FCSAP sites. A list of metals and organic contaminants considered relevant for fish and aquatic environments were selected for inclusion in this project. Fish-specific TRVs were identified through a literature search, and review of selected ERA case studies from federal sites. Each candidate TRV was then evaluated against a set of criteria (similar to those used for selecting default wildlife TRVs for FCSAP in Module 7) identifying its merits, limitations and uncertainties. Recent water quality guidelines from Canadian Council of Ministers of the Environment (CCME), Environment and Climate Change Canada, and the US Environmental Protection Agency were also reviewed for their potential suitability to be used (a) directly as fish-specific TRVs or (b) as the basis for future development of fish-specific values. Availability of fish-specific TRVs for selected contaminants based on water concentrations and tissue concentrations are summarized in tables. Results can be used to (1) identify where a suitable fish-specific TRV already exist, and (2) to highlight where effects information may be limited for a given contaminant (thus necessitating development of site-specific TRVs and/or use of other lines of evidence). Results of this work have been prepared for Public Services Procurement Canada on behalf of Fisheries and Oceans Canada’s FCSAP mandate, and could serve as the basis for development of a future ERA Guidance Module.

Patrick Allard, Azimuth Consulting Group Partnership
Patrick Allard has over 22 years of experience in environmental consulting and risk assessment/management. He has overseen and implemented several projects including risk assessments of complex marine and terrestrial contaminated sites. He has expertise in developing conceptual models to help structure and guide risk-based decision-making, including communication to technical experts and stakeholders. Patrick is a lead author of risk-based technical guidance for environmental monitoring and impact assessment of marine oil spills for Fisheries and Oceans Canada. He is also a risk AP with the Contaminated Sites Approved Professionals Society (CSAP Society).

Ryan Hill, Azimuth Consulting Group Partnership
Ryan Hill has over 24 years of experience in environmental consulting and policy development, including 13 years with Azimuth. He has managed and implemented several projects including risk assessments of complex contaminated sites. Ryan is widely recognized as an expert in ecological risk assessment (ERA), and was the lead author of the federal ERA guidance prepared by Environment and Climate Change Canada under the Federal Contaminated Sites Action Plan. Meara Crawford, Azimuth Consulting Group Partnership Meara Crawford has over seven years of experience as an environmental biologist working in both consulting and with BC provincial and federal government departments. She previously worked with FCSAP Environment and Climate Change Canada and Fisheries and Oceans Canada expert support departments on ERA guidance selecting default wildlife TRVs.

Fisheries and Oceans Canada (DFO) are currently the custodian for 53 light stations throughout Newfoundland and Labrador. Many of these light stations were contaminated due to activities such as improper waste management, use of toxic substances (e.g., mercury, lead) in light station operation, and improper fuel handling that occurred before their environmental impact was fully understood.

With advances in marine navigational technology, many light stations have been automated, decommissioned or divested to private or provincial entities for use as tourist attractions. Others remain operational under a wide range of staffing scenarios. In anticipation of the changes in light station requirements, DFO embarked on an ambitious program to conduct environmental assessments at their light station properties in Newfoundland and Labrador. Over the past twenty years, the assessments have included phase I, phase II and phase III environmental site assessments, human health risk assessment, ecological risk assessments, and remediation. These environmental assessments have been conducted with consideration of a wide range of potential land use scenario outcomes and divestiture options. While the challenges associated with accessibility and characterization of light stations have been discussed from an environmental site assessment perspective, the remarkable challenges the light stations present to risk assessors has received less attention. This presentation will highlight some of the unique scenarios that risk assessors have encountered during the human health and ecological risk assessment of light stations in Newfoundland and Labrador over the past twenty years while also exemplifying the success of the program. We will provide a summary, with examples, of how consideration of human and ecological risk has enabled the successful decommissioning, divestiture, automation, and modified staffing of light stations in Newfoundland and Labrador. We will also highlight the unique opportunities light stations provide to risk assessors to apply novel thinking in consideration of unconventional human and ecological receptors and exposure scenarios as well as unique ecological food webs that have evolved on the isolated islands. These challenges will be discussed with real examples/case studies and within the context of the program’s success since its implementation twenty years ago.

Kelly Johnson, Senior Human Health and Ecological Risk Assessment Specialist, CBCL Limited
Kelly Johnson is a Senior Human Health and Ecological Risk Assessment Specialist with CBCL Limited in Newfoundland and Labrador. Kelly has nineteen years of experience conducting environmental site assessments and human health and ecological risk assessments and has worked on many complex sites in Canada as far north as Nunavut. She has extensive experience working on a diversity of contaminants on sites ranging from small residential oil spills to the larger Pinetree and Mid Canada Line Military Radar Stations. In her current role, Kelly manages the technical aspects of environmental site assessments and human health and ecological risk assessments conducted by CBCL in Newfoundland and Labrador and provides input and guidance on assessments conducted across Canada.

Kelly’s Ph.D. research focused on the ecological risk assessment of polychlorinated biphenyls (PCBs) contamination at Saglek, the site of a former United States Military Polevault Radar Station in Northern Labrador, using biomarker responses to determine effects on terrestrial and marine wildlife. This research represented some of the first biomarker research that was combined with theoretical risk assessment modelling and tissue analysis to determine potential effects and risk to wildlife.

Kelly also represents CBCL as a regional consulting professional on the Atlantic PIRI committee.