FCSNW2018 English header

Metro Toronto Convention Centre 
255 Front St West, North Building, Toronto Ontario 
June 13-15, 2018 

Poster Abstracts
Health Canada Guidance on Human Health Risk Assessment of Contaminated Sediments: Direct Contact Pathway
Deanna Lee, Meghan Roushorne, Odette Bose, Darcy Longpre, Marie-Josee Poulin, Sanya Petrovic and Louise White
Health Canada
The objective of this presentation is to promote awareness of Health Canada's supplemental guidance on human health risk assessment of contaminated sediments on the direct contact pathway.

Aquatic sites with contaminated sediment are often a greater challenge to characterize, assess and manage than terrestrial sites because of the unique characteristics associated with sediments. In the absence of human health-based sediment guidelines, residential soil quality guidelines for the protection of human health have been used in lieu of sediment based values to determine protection of human health from exposure to contaminated sediments; however, human activities and exposure characteristics at aquatic sites differ from those associated with terrestrial sites. Use of human health soil criteria may not be appropriate for use at sediment sites because human activities, exposure scenarios, sediment characteristics and receptor characteristics differ at sediment sites in comparison to terrestrial sites. Health Canada has developed risk assessment guidance related to evaluating human exposure to chemicals in sediments via direct contact (i.e., incidental ingestion, dermal contact and inhalation of particulates). Health Canada’s approach to human health risk assessments at federal Canadian contaminated sediment sites will be presented.

Health Canada has recently developed guidance on conducting human health risk assessments for contaminated sediment sites. Guidance on conceptual site models, exposure scenarios and receptor characteristics that are specific to sediments is provided. Three generic sediment exposure scenarios (recreational high contact, low contact and commercial/industrial) representative of typical human activities that may occur at sediment sites are discussed. The guidance specifies the use of sediment-specific receptor characteristics such as dermal loading (or adherence) factors, incidental ingestion rates and exposed skin surface area that may be more appropriate for sediment exposure scenarios than those used for terrestrial activities associated with soil to better estimate risks associated with contaminated sediment exposure.

Results/Lessons Learned
The derivation of national sediment guidelines for human health has proven difficult due to the wide variation of sediment sites in Canada, not only by the different types of sediment sites dictated by sediment characteristics, settings and location, but also by the wide array of human activities, exposure duration and frequencies that can occur from one sediment site to another. In the absence of national sediment guidelines, Health Canada has developed guidance on conducting human health risk assessment on contaminated sediment sites in Canada. The refinement of sediment exposure estimates using sediment-specific factors for direct contact can provide much different exposure estimates in comparison to terrestrial sites due to sediment specific characteristics.

Artificial Sweeteners as an Indicator of Human Impacts: Occurrence, Mobility and Sampling Best Practises
Emily Saurette, InSitu Remediation Services Ltd.
The objective of this presentation is to highlight the relationship between contaminants of concern and artificial sweeteners, and provide an overview of the occurrence, mobility and sampling best practises for artificial sweeteners to facilitate their potential use as a risk management tool.

Artificial sweeteners have been identified as indicators of many contaminants of concern due to their ubiquitous nature in human effluent and occasionally livestock effluent. Groundwater and surface water samples collected and analyzed for artificial sweeteners have shown high concentrations in urban areas across Canada. These compounds can also be used as groundwater tracers because of their conservative behaviour. In Canada, the artificial sweeteners acesulfame, sucralose and saccharin are sold as tabletop sweeteners and used in a large number of consumer products including beverages, canned foods, condiments and chewing gum. The unique chemical properties of artificial sweeteners, which resist degradation during the digestive process and result in a calorie-free product, also allow these compounds to act recalcitrantly in both groundwater and surface water systems. Artificial sweeteners have been associated with effluent entering groundwater and surface water from septic beds, landfills and wastewater treatment plants – even after tertiary treatment.

Monitoring of artificial sweeteners in water bodies can provide a precise indicator of anthropogenic impacts to groundwater and connected surface water bodies. Artificial sweeteners are associated with the presence of other contaminants such as pharmaceuticals, personal hygiene products and disinfection by-products. As compounds that are difficult and/or expensive to analyze become recognized as contaminants of concern, the analysis of artificial sweetener in environmental water samples may become a powerful tool for risk management at appropriate sites. Samples for artificial sweetener analysis are easy to collect and can be stored for extended periods of time with relatively little preservation which is beneficial for sampling programs. Understanding the potential harm of elevated artificial sweeteners to aquatic species and the relationship between artificial sweeteners and other contaminants will be important as populations become denser and the environmental concentrations of currently dilute contaminants increase.

This presentation will explore the current and past literature on the occurrence of artificial sweeteners compounds in the Canadian environment; their mobility in groundwater; the relationship between artificial sweeteners and other compounds of concern; and, sample collection and storage best practises.

Use of Bench-Scale Testing for Successful Remedial Design
Kevin French, Vertex Environmental Inc.
The objective of this presentation is to demonstrate the advantages of using bench-scale treatability testing to allow more effective and efficient full-scale remedial designs to be developed and avoid making costly mistakes in the field.

The success of full-scale remediation programs is dependent upon many factors, some of which may be unknown prior to commencement of clean-up efforts. Bench-scale testing can be used to quantify many variables and reduce the need for assumptions that can lead to uncertainty, inefficiency and sometimes even failure. For example, bench-scale testing can assess the optimal types and concentrations of remedial amendments, reaction/contact times, generation of by-products/residuals, etc. Experimenting on samples of soil and groundwater collected from the actual site can lead to many key findings that ultimately reduce uncertainty and maximize the chances of success for full-scale remedial efforts.

This poster will display examples of bench-scale experiments that have been completed for real world, Canadian sites demonstrating the range of results possible and how those results were incorporated into full-scale remedial designs.

The poster will also present an overview of the types of bench-scale testing that can be completed, from relatively quick and easy static batch reactors to more complex, multi-variable, flow-through column reactors. Case studies will be included where bench-scale testing was used to evaluate:

  • Proof-of-concept testing that acid rock drainage (ARD) could be treated to aquatic discharge standards with less than one day of contact time;
  • Optimal chemical oxidation method for contaminated groundwater as a function of reagent type, dosing and reaction time;
  • Feasibility of stabilizing leachate toxic lead in soil to render it non hazardous; and,
  • Effectiveness of various filtration/adsorption media in treating a complex wastewater stream in support of a treatment system design.

The poster will conclude with how quick and inexpensive bench-scale testing can be applied to real-world impacted sites to demonstrate treatability (ability to meet remedial targets) and to refine designs to maximize efficiencies, minimize project costs and maximize the chances of success for full-scale remediation efforts.

Soil and Sediment Stabilization/Solidification Technology as a Cost Effective Tool for Heavy Metal Risk Management for Contaminated Soil and Dredged Sediments
B.J. Min and Jevins Waddell
TRIUM Environmental Inc.
The objective of this presentation is to share scientific knowledge and research project experience with audience to improve awareness of alternatives for risk management at contaminated sites

Soil stabilization/solidification (S/S) is a widely used technology to assist risk-based management and closure options for heavy metal contaminated sites including oil and gas, mining, industrial properties, hazardous waste and/or material management sites, sludge and dredged marine or watershed sediments. Stabilization of heavy metal impacted soil operates to convert the heavy metals into insoluble precipitates whereas stabilization is achieved through sorption of the contaminant into the mixed S/S product and soil matrix.

The mechanisms of available S/S technologies and the applications for inorganic and organic contaminants, as well as a wet soil moisture stabilization agent, will be summarized. Cement-based S/S products (such as pozzolan) are commonly used for the purpose, however, the cement-like nature, bulking and limited re-vegetation and reclamation capabilities inherent to this product, cause limitations to sustainable contaminated site management.

After analytical assessment of various S/S technologies, this poster identifies sustainable methods to stabilize inorganic and/or organic contaminant impacted soils, with a focus on leachate prevention, re-vegetation and reclamation and sustainable uses of contaminated sites under risk management. Several case studies of sustainable technology field scale applications will be included to demonstrate the conclusions.

Phased Approach to Perfluorinated Compounds Investigation, Remediating / Risk Planning and Management – An Airport Facility Example
James Mair, Hemmera Envirochem Inc., an Ausenco Company
The objective of this presentation is to provide a cost-effective, real world example of a phased approach for remediating a site that has been impacted by PFCs, will demonstrate the effective methods for detecting and remediating PFCs in the context of this site and potential future use, and will showcase the detection and remediation strategies required to enable site redevelopment.

The poster will highlight the focused investigations on the occurrence of Perfluorinated Compounds (PFCs) in the soil and groundwater at the site in an active airport context. In an airport context, PFCs can be associated with firefighting foams (e.g., aqueous film forming foams (AFFFs)) used for fighting fuel-related fires, as well as in aviation hydraulic fluids. The use of AFFF has led to groundwater and surface water contamination in affected areas, a problem made worse by the ability of some PFCs to migrate through water. Regulatory bodies have recently recognized PFCs as an emerging group of contaminants of concern.

The site was historically agricultural and vegetated lands back to at least the 1930s. From the 1940s to the 1970s, the Royal Canadian Air Force (RCAF) occupied the site with barracks and other structures related to air force operations. In the late 1970s, the site was redeveloped as an airport maintenance facility and was in use until 2015. As PFCs have become increasingly important, their investigation was included as contaminants of concern during ongoing investigations at the site. Vancouver International Airport (YVR) determined it was cost effective to include PFCs in this investigation for general information purposes.

In our poster we will use this study site, which has been impacted by PFCs, to illustrate a phased approach to investigation and remedial planning to support property redevelopment. The phased approach in this case involved the following steps, which will be highlighted in detail in the poster:

  • Phase I ESA – understanding the possible source(s) of the PFCs on site which drives decisions for site investigation(s) e.g., where additional investigations are warranted.
  • Conceptual Site Model Development – use of a combined conceptual site model (CSM) and human and ecological exposure model, and how to evaluate PFCs in a CSM context.
  • Phase II and III ESA – to further understand the site characteristics and delineation of PFCs. The poster will also highlight the investigation methods and analytical program/analytes.
  • Regulatory Regime for PFCs – YVR utilizes multiple regulatory jurisdictions, with Federal guidelines in draft and recently adopted Provincial standards. The poster will highlight the regulatory regime in the context of an airport site in BC.
  • Remedial Options Evaluation/Strategy – the poster will highlight the evolving remedial considerations, as well as the options considered in this evaluation, including: risk assessment; source removal of contaminated groundwater and ex-situ treatment; and, installation and operation of a pump-and-treat recover system.
  • Screening Level Risk Assessment – used to evaluate the risks associated with PFOS concentrations at the site, and to provide a realistic determination of the environmental and health concerns (if any) associated with PFCs (including PFOS), identified in the site investigation process. The poster will highlight the framework (including Health Canada draft guidelines, screening values and interim toxicological reference values for perfluoroalkyl substances for which the assessment was completed.

In summary, a well thought out phased investigation, as well as a CSM, can lead to refined site management objectives which lead to more focused risk assessment evaluations.

Challenges of Treating PAH Compounds to Low Limits
Jason Downey, Newterra Inc.
The objective of this presentation is  to share experiences treating PAH compounds to low levels.

As discharge regulations continue to tighten across North America solution providers are required to evolve and adapt products and designs to meet new regulations.

In 2015, a process design was developed and delivered a treatment plant for remediating a heavily contaminated superfund site situated on the environmentally sensitive shore of Lake Superior. As a former manufactured gas plant this site contains large volumes of weathered LNAPL and DNAPL that has been collected and treated along with the heavily impacted groundwater and solids drawn from multiple extraction wells on the property.

The effluent from the treatment plant discharges to Lake Superior and was subject to strict permit requirements with discharge limits in the part per trillion range for the difficult to treat PAH compounds.

This poster will guide the audience through the treatment objectives and challenges faced in developing the solution on this site. It will showcase the process of bench testing, pilot testing and full scale design of the treatment plant and share the lessons learned through commissioning and start up of the plant.

By sharing the challenges, technology selection, and experiences, delegates will be able to apply these experiences to their own water treatment challenges and build upon the lessons learned shared.

How Not to Find Water Lines on First Nation Reserves and What to Do When You Do: A Case Study of a Waterline Break at Kehewin Cree Nation
Barbara Petrunic1, Andrew Thalheimer1, Alain Joly2
1Dillon Consulting Limited
2Kehewin Cree Nation
The objective of this presentation is  to illustrate that a) following standard industry practice for utility locates is not always enough to avoid hitting an underground utility; b) the best response is proactive and solution oriented; and, c) engaging the stakeholders throughout the project facilitates cooperation and support during an emergency.

In the middle of winter in northern Alberta, during remediation of a former underground storage tank, at the end of the final day of soil removal, an unmarked waterline was struck in the commercial centre of the community. This immediately causing the excavation to fill with water and cut off water services to the Kehewin Cree Nation community. Due to weather and available resources, the First Nation was without their own water supply for a number of days.

This poster will review the standard industry approach for and challenges associated with locating utilities in First Nations communities (as employed on this project); discuss the project specific conditions leading to the waterline being struck (e.g., type of pipe, depth of pipe, available information on pipe location); detail the emergency response undertaken to restore water services to the community including ancillary activities such as alerting residents and arranging temporary water supply to the community; highlight the value of open communication, stakeholder collaboration (including Department of Indigenous Services Canada for whom the work was being conducted, Health Canada who was called to address the lack of potable water, various departments within the Kehewin Cree Nation including Kehewin Public Works, and numerous subcontractors and suppliers), and First Nation engagement; and, identify the lessons learned. Specifically, this poster will share the perspectives of those who were conducting the work and those who were affected by the waterline strike, and how they worked collaboratively to resolve the issue under very difficult conditions including extreme cold temperatures, reduced daylight hours and limited availability of service providers in the area.

Development of Canadian Soil Quality Guidelines for PFOS and PFOA
Luigi Lorusso1, Darcy Longpre1 and Philippa Cureton2
1Health Canada
2Environment and Climate Change Canada
The objective of this presentation is  to bring awareness to the Canadian Soil Quality Guidelines for PFOS and PFOA. The derivation process and scientific supporting documentation for both the human health and ecological components will be outlined.

In recent years perfluoroalkylated substances (PFAS) have been the focus of much attention due to their persistence and unique chemical properties. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are generally entering the environment in mixtures that contain several PFAS and their associated precursors. PFAS may be found in areas distant from any source due the environmental fate and behaviour of this group of chemicals.

Numerical values that can be used to screen soils at potentially contaminated sites are necessary to assess and manage contaminated sites. Health Canada and Environment and Climate Change Canada have developed soil screening values (SSVs), for use at Canadian federal sites, for several PFAS following A Protocol for the Derivation of Environmental and Human Health Soil Quality Guidelines (SQGs) (CCME 2006). Interim values are now available for PFOS (ecological and human health), PFOA (human health) and others are currently being developed. These same values, accompanied by scientific supporting documentation, will undergo a peer review process before being considered as Canadian Environmental Quality Guidelines (CEQGs, or SQGs in the specific case of soil) by the Canadian Council of Ministers of the Environment (CCME).

The derivation process for the development of the human health values for PFOS and PFOA will be presented. The ecological values for PFOS will be described briefly as will future work.

Materials and Methods
In order to derive environmental quality guidelines for PFOS and PFOA, reviews of the chemical and physical properties, sources and emissions in Canada, environmental fate and behaviour, and toxicological effects in environmental species, humans and laboratory animals were carried out (Sanexen 2015a; b). Human toxicology and ecotoxicology were evaluated separately to identify the critical effects and their corresponding doses. This information was used to determine the critical dose levels (TRVs) or concentrations that elicit adverse effects in human or ecological receptors occupying different trophic levels and environments.

This information, along with a review of behaviour and effects in biota, estimations of daily intake by humans, bioaccumulation and bioconcentration potential, and exposure pathway-specific information were used to calculate soil quality guidelines to protect environmental (PFOS) and human (PFOS and PFOA) receptors for four land use scenarios: agricultural, residential/parkland, commercial and industrial. SSVs for each of four land use categories are the lowest of the component (pathway) values and applicable check values calculated for ecological and human receptors.

Results and Discussion
The proposed SSVs for PFOS are: 0.01 mg/kg for agricultural and residential land uses and 0.14 mg/kg for commercial and industrial land uses. These PFOS values are based on the protection of environmental health, as these values were lower than the values calculated for the protection of human health. The proposed human health SSVs for PFOA are: 0.85 mg/kg for agricultural and residential land uses; 1.28 mg/kg for commercial land uses; and 12.1 mg/kg for industrial land uses. The PFOA values are based solely on the protection of human health since no values for the protection of environmental health could be calculated at the time of publication.

The health effects of PFOS and PFOA are similar and well documented. Thus, when PFOS and PFOA are found together in soil, it is recommended that these chemicals be considered additive when comparing to the SSVs.

Shamattawa First Nation Soil Remediation project
Syed Wasay1, Shelly Johnson1, Ken Einarsson1, Christin Didora2, Mark Hadfield3
1Department of Indigenous Services Canada
2Health Canada
The objective of this presentation is  to highlight remediation challenges at remote communities.

At the request of Shamattawa First Nation (SFN), environmental site assessments (ESA) and subsequent remediation of impacted soils were conducted at two sites within the community. These sites were contaminated with petroleum hydrocarbons (PHCs) such as BETX and Fraction Fl to F4. The objective of this project was to protect human health and the environment including historical burial sites riverbank ecosystems and community infrastructure present at the sites.

SFN is located along the northern shore of God's River in Northern Manitoba and is accessible by air year-round, by seasonal road and by ice roads during the winter months. SFN operated two historic sites on the community, a former nursing station site (FNSS) and a former school site (FSS) from 1950s to 1980s. Both sites used diesel and fuel oil tanks as heating sources and during operations, historical leaks and poor filling practices for the diesel and fuel oil tanks resulted in spills believed to have contaminated the soils around the facilities.

Phase I/Il/Ill ESA determined that both sites should be classified as Class 1 sites requiring remediation. A remediation action plan (RAP) was developed including a remediation technology evaluation. The finding of the evaluation indicated that excavation with shoring and ex-situ treatment of the soil (landfarming) was considered to be the most applicable remediation technology for both sites. This excavation with shoring option was selected in order to protect the historical gravesites adjacent to the sites, the riverbank and its surrounding environment, and the community's water intake infrastructure present on both sites. The excavated soil contaminated with PHCs was transported to an existing landfarm facility and is estimated to require approximately three years to treat. The excavated areas on both sites were backfilled with clean soil from the perimeter of the excavation and imported clean fill. The final surface will be amended with peat moss, clean topsoil and vegetation cover. Finally, the sites will be redeveloped for commercial or recreational purposes after the site have settled and stabilized.

In conclusion, both sites were successfully remediated despite the challenges of weather, significant shoring requirements in a remote location, protection of historical burial sites, major river bank and community infrastructure.

Applying Multiple Risk Management and Remediation Approaches to Achieve Site Closure at a Former Industrial Landfill Site
Melanie Siewert and Darren Dickson
SNC-Lavalin Inc.
The objective of this presentation is  to discuss the various Federal Contaminated Sites Action Plan steps implemented to achieve site closure of a former landfill site for the federal custodian.

To achieve site closure at a Correctional Service Canada (CSC) institution in Ontario, Public Services and Procurement Canada (PSPC) issued a contract to provide environmental consulting services to consolidate two former non-engineered landfills into a single waste disposal area within an area of the institution property removed from sensitive receptors.

Steps 1 to 6 of the Federal Contaminated Sites Action Plan (FCSAP) Decision-Making Framework, completed from 1998 to 2013, identified these landfills within the institution property. One landfill was constructed in a former limestone quarry and was backfilled with a variety of materials, including institutional waste, construction debris and domestic waste. The other landfill was a small ravine infill adjacent to a Provincial Class 1 Wetland and a small creek flowing adjacent to the toe of slope of the landfill (and over some residual waste) discharged to this wetland. Potentially asbestos containing materials were identified within the second landfill.

As both areas were surrounded by active agricultural cultivated lands, FCSAP Step 5 involved completion of site specific risk assessments (SSRA) for each landfill site. Human health modelling included assessment of potential risks to farmers engaged in cultivation of the lands as well as members of the public consuming agricultural products from the site. Modelling did not identify significant risk to human or livestock consumers; however, concerns remained with respect to environmental impacts due to the proximity of one of the landfills to the sensitive aquatic receiving environment. A weight of evidence (WOE) assessment, including groundwater, sediment, surface water, fish tissue and plant tissue sampling programs, was completed and employed multiple lines of evidence for sediment evaluation (i.e., sediment chemistry, toxicity testing and benthic invertebrate community structure analysis) relative to the Environment Canada (2008) framework. From the results of the WOE assessment, no new unacceptable risks were identified to aquatic receptors and the results of the SSRA were validated.

In 2015, FCSAP Steps 7 to 9 were completed and site closure was achieved when PSPC, CSC and the contractor completed a remedial options analysis that recommended the design and implementation of a plan to consolidate the two landfills by removing waste in proximity to the sensitive aquatic receptors. Detailed design and specifications included steps to excavate and relocate the waste material, upgrades to the haul roads, improvements to local drainage, use of relocated waste material to improve grading at the former quarry landfill and design and construction of an engineered cap. The design minimized requirements to import materials, avoided transporting waste off-site, and met the goals of the local conservation authority to support wetland re-naturalization.

Rogers Pass National Historic Site – Glacier National Park: Challenges of Conducting Contaminated Site Remediation in a Mountain Park and National Historic Site
Bruno Delesalle and Albert Rand
Mount Revelstoke and Glacier National Parks, Parks Canada Agency
The objective of this presentation is  to share the challenges Mount Revelstoke and Glacier National Park Field Unit faced at the Rogers Pass contaminated site while of conducting remediation in a mountain park and National Historic Site.

Contaminated site investigation, remediation and management is complex. Numerous historic buildings situated on top of a contaminated site, combined with several adjacent federal infrastructure investment (FII) projects, high potential to un-earth archaeological resources, record high visitation and a site that receives 10 meters snowfall annually, amplifies these complexities.

Rogers Pass is one of the largest federally listed contaminated sites managed by Parks Canada and in late 2016 was approved for funding through FCSAP to abate and demolish the former Glacier Park Lodge (GPL) and Service Station, and remediate the contaminated site. This site is located on the west side of the TransCanada Highway (TCH) at the summit of Rogers Pass, directly adjacent to the existing Rogers Pass Discovery Center (RPDC), an active visitor experience information and interpretive center.

From 1884 to 1919, this site was home to historical railway activity including a railway station. In 1956 the site was transformed for construction of the TCH through Rogers Pass which opened in 1962, this also marks the beginning of construction on the GPL and Service Station. Railway operations, construction of the TCH and the operation of the GPL and Service Station all resulted in significant soil and groundwater contamination.

Since 2010, environmental site investigations and remedial activities have indicated extensive shallow-source hydrocarbon contamination in soil and groundwater beneath and surrounding the GPL and Service Station. It is estimated that approximately 6000 m3 of contaminated soil requires remediation. In addition to shallow-source contamination, deeper contamination (up to 12 mbgs) of high-viscosity petroleum hydrocarbons, thought to be linked to heavy oil releases from historical railway activities, is present in the central portion of the site.

Mount Revelstoke and Glacier National Park (MRGNP) Field Unit assumed responsibility of both GPL and the Service Station through a court settlement in 2016. In early 2017, both buildings were assessed as uninhabitable and found to be contaminated with extensive hazardous materials such as asbestos, mould, lead and mercury. Due to the poor condition of these buildings, combined with the hazardous materials within them and underground contamination, the decision was made to abate and demolish both buildings and conduct soil remediation in 2018.

Demolition and site remediation will significantly reduce the health risks and liability to Parks Canada, while providing an important opportunity to reinvent a vision for Rogers Pass, including a new washroom facility and day use area with potential future accommodation or camping offers.

Successful completion of this project will not only be measured by enhancing ecological integrity and eliminating risks to human health through environmental remediation but also by the ability of the MRGNP Field Unit to successfully coordinate implementation of three other large-scale projects within close proximity to the remediation project. This project represents a significant step forward in the remediation of a Parks Canada contaminated site, while preparing the site for future visitor experience offers. A long-term monitoring program will be implemented as the MRGNP Field Unit move towards closure of the site under FCSAP.

Improved fish habitat quality after rehabilitation of contaminated sediment, Gaspé – Sandy Beach, Quebec
Marc Desrosiers1, Isabelle Lefebvre2, Linda Roberge3
1Public Services and Procurement Canada
2Englobe Corp.
3Transport Canada
The objective of this presentation is  to demonstrate the benefits of contaminated sediment rehabilitation work on fish habitat.

With the objective of improving the quality of the marine environment, in 2016, Transport Canada rehabilitated 40,000 m3 of sediment that was contaminated with copper and polycyclic aromatic hydrocarbons over a surface area of 50,000 m2 near its facilities in Gaspé. Characterization work on the marine floor, wildlife and plants completed before the dredging work in 2012 and one year after the rehabilitation work in 2017 made it possible to see the changes made to the fish habitat.

The characterization of the marine floor and the inventory of aquatic plants and wildlife were completed using divers, an underwater camera and a two-way communication system. Divers sent up information to the surface team on the nature of the substrate and the presence of vestiges, aquatic vegetation and fish or benthic organisms along defined transects.

Results show that the rehabilitation work next to the Transport Canada wharf in Gaspé improved the quality of the fish habitat by diversifying the nature of the substrates, increasing the surface areas suitable for colonization by laminaria and organisms such as mussels, increasing the abundance of individuals while maintaining diversity. Monitoring will be required over the next few years to follow the recovery of the eelgrass bed destroyed by the work.

Sediment rehabilitation in Gaspé is part of the Federal Contaminated Sites Action Plan and is the result of close collaboration between Transport Canada, Environment and Climate Change Canada, Fisheries and Oceans Canada, Health Canada and the Government of Quebec – Ministère du Développement durable, de l’Environnement et de la Lutte contre les Changement climatiques.

Per- and Polyfluoralkyl Substances: Navigating through Regulatory Uncertainty
Shalene Thomas, David Woodward and Nathan Hagelin
Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to provide a global picture of the emerging contaminant class, showcase what geographies are considered high priority based on current regulations, as well as what to consider to manage, mitigate and eliminate liability if you are currently using or have historically used PFAS.

Emerging contaminants have been defined as those chemicals or materials that have a perceived, potential, or real threat to human health or the environment, lack published health standards, and/or new source or pathway information has become available. Emerging contaminant programs were developed nearly a decade ago across the globe. Despite being around for almost ten years, emerging contaminants have not had elevated and extensive visibility until very recently with the momentum of contaminants such as 1,4-dioxane and per- and polyfluoroalkyl substances (PFASs).

If no promulgated health criteria are available, and the science surrounding these contaminants continues to evolve, how have they become such hot button liability issues globally? What key factors led us to where we are today and how will these factors influence the regulatory direction of future emerging contaminants? How do we navigate in such uncertainty to manage and reduce potential liabilities?

Key factors that have led us to where we are today. Using PFASs as an example, the history and timeline of regulatory, social, and litigious activity will be presented as well as the associated research progress, trends, and challenges that are arising as regulations continue to develop. An overview of the various international, federal and state emerging contaminants programs will be presented and regulations in the US, Canada, and Australia will be discussed in relation to their part in elevating PFASs to the priority status they currently have today.

What factors influence the direction of future emerging contaminants? Reactions to PFASs from government, industrial sector, and water authorities will be discussed. Proactive legislation at various state, federal, and international levels that ensures lines of liability are clearly defined will be presented.

How do we navigate in such uncertainty to manage and reduce potential liabilities? By performing a desktop liability evaluation, information can be generated for site managers to qualitatively forward-thinking programmatic infrastructure to support regulatory action will be highlighted.

What to take-away? Whether in industry, government or the private sector, emerging contaminants will continue to be defined for years to come and a programmatic evaluation of historical activities and current operations will successfully enable any organization to better prepare for and proactively manage the future evolution and liability of these dynamic group of chemicals.

Characterization of the Nuclear Power Demonstration Site
Meggan Vickerd1 and Paul Hurst2
1Canadian Nuclear Laboratories
The objective of this presentation is  to share the details and results of the site characterization of the nuclear power demonstration site, which applied both federal and provincial requirements for radiological and chemical contaminants of concern.

Canadian Nuclear Labs (CNL) contracted the conduction of a phase two environmental site assessment (Phase Two ESA) of the Nuclear Power Demonstration (NPD) property located in Rolphton, Ontario. The NPD facility consists of a shutdown 20 MW CANDU (short for CANada Deuterium Uranium) reactor which was placed in service in 1962 and was operated until 1987. The site owner is Atomic Energy of Canada Limited and is operated by Canadian Nuclear Laboratories under a government owned contractor operated (GoCo) contract. The NPD site is currently designated as Federal crown land and is an industrial site with a Class 1 Nuclear Facility licence under the Nuclear Safety Control Act. Canadian Nuclear Laboratories is proposing to safely decommission the NPD facility to complete the closure of the site, which includes verifying the environmental liabilities of the site.

The Phase Two ESA was undertaken with the general objective of determining the environmental condition of the NPD site in terms of contaminants of concern (COCs), both radiological and chemical parameters, relative to both federal and provincial environmental standards for more sensitive land uses (i.e., residential/parks/institutional property). At the present time, no alternative land use plans have been developed for the site. The characterization was performed for the purposes of liability definition. Although Provincial Ontario regulations do not apply to the site, CNL applied O.Reg 153/04 for the purposes of the Phase Two ESA as best practice/due diligence. Furthermore the characterization has been completed to the appropriate requirements set forth in CSA Z769 (Phase II Environmental Site Assessment) as well as CSA N292.5-11 (Guideline for the exemption or clearance from regulatory control of materials that contain, or potentially contain, nuclear substances).

The comprehensive Phase Two ESA included field sampling of soil, sediment and groundwater and analysis for all potential COCs (i.e., radiological and conventional) at target locations across the NPD site. To ensure the requirements of CSA N292.5-11 were met, a statistical rationale was used for the selection of sample locations based on a 95 percent upper confidence level. Further the entire site was subdivided into characterization units and the density of sampling was based on risk of historic impact. In total, over 400 soil samples and 24 groundwater samples were collected and analyzed for radiological and conventional parameters. The Phase Two ESA also included the assessment of sediment quality at 16 locations in the Ottawa River upstream, adjacent to and downstream of the NPD site. Finally, two areas identified by CNL where suspected historic unauthorized dumping had occurred and one area where vehicle maintenance had occurred were investigated.

Samples were submitted for analysis of both radiological and chemical parameters. The contractor assessed and prepared the Phase Two ESA report for the chemical COCs in accordance with O.Reg 153/04 using both Ministry of Environmental and Climate Change (MOECC) standards and Canadian Council of Ministers of the Environment (CCME) environmental quality guidelines. CNL prepared a site clearance report for the radiological COCs in accordance with CSA N292.5-11 using the Nuclear Substances and Radiation Devices Regulations (SOR-2000-207).

This poster will present the details and results of the site characterization of the NPD site, which applied both federal and provincial requirements for radiological and chemical contaminants of concern.

Customized Remediation Requirements to Address Risks while Minimizing Damage to the Existing Ecosystem
Darren Dickson, SNC-Lavalin Inc.
The objective of this presentation is  to show that innovative approaches can be applied to remediate and manage risk, and ultimately achieve site closure, at sites presenting significant technical and logistical challenges for site custodians.

Defence Construction Canada (DCC), on behalf of Department of National Defence (DND), retained environmental consulting services in support of decommissioning former military rifle range and training area. Proposed assessment and remedial activities at the site were complicated by the site’s potential historical significance as an invasion landing site during the War of 1812; classification of a portion of the site as an area of natural and scientific interest (ANSI) with one of the last tracts of old growth Carolinian forest in southwestern Ontario; the confirmed presence of species at risk (SAR); and, the need for substantive clearances and avoidance activities relating to potential unexploded ordnance (UXO) risks. This presentation will focus on the measures taken to manage these challenging complications during execution of field assessment programs and in proposing and executing risk management measures.

Use of the property by DND since the early 1900s has included tank training manoeuvres, various firing ranges (rockets, grenades, rifles, small arms), disposal of residual incinerator ash and landfilling of non-combusted waste. Potential contaminants of concern (COCs) included metals and other inorganics, residual energetics (explosives), petroleum hydrocarbons (PHCs), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and leachate contaminants associated with the former landfill.

A phased approach was applied to field activities by developing a GIS database of existing environmental information for the site and utilizing an existing monitoring well network to refine initial investigations. Supplementary site investigations were then completed to distinguish background soil conditions (such as low pH and elevated naturally occurring metals concentrations) from impacts associated with former site uses. Confirmed COCs were carried forward to a detailed quantitative human health and ecological risk assessment. A further weight-of-evidence (WOE) assessment was completed to evaluate potential environmental risks ubiquitous at the site that could not be remediated without removal/destruction of the ANSI and the known SAR.

The WOE compared environmental conditions at the site to nearby reference sites. The additional studies included a small mammal catch and release program, invertebrate biomass assessments in soil and a phytotoxic visual assessment. The results indicated that the COCs identified in the ANSI areas (including old growth forest) were unlikely to be impacting the environmental health of the ecosystem, and that the “do no harm” principle would suggest that attempts to remediate what might be naturally occurring elevated concentrations for some parameters would result in unjustifiable environmental destruction. As a result, it was concluded that remediation recommendations could be significantly reduced. A remedial alternatives analysis for specific remaining issues evaluated various options to address COCs, including on-site treatment of hazardous soil (due to the presence of elevated lead), using the data from a bench scale treatability study on selected samples collected from the site.

Hazardous Building Materials – Key Components to Managing Your Building Project from Proposal Development to Closure
Patrick Campbell, Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to provide anyone who manages a project involving hazardous building materials an understanding of where they may be found, the current legislation across Canada and common best practices through the project lifecycle.

Background/Objectives. Hazardous building materials (HBMs) are a common component to a project coordinator’s portfolio of environmental projects. While HBMs are common, managing these projects can be very complex dealing with a mix of environmental and labour regulations across Canada and challenges with remote northern sites and new ‘green’ building initiatives. The mere mention of asbestos or mould in some workplaces can create fear and concern. Even the terminology applied to these materials; designated substances, hazardous materials and regulated building materials, is not consistent across Provincial jurisdictions. The objective of the presentation is to provide anyone who manages a project involving HBMs an understanding of where they may be found, the current legislation across Canada and common best practices through the project lifecycles as it relates to Federal departments including Defence Construction Canada, Department of National Defence, Indigenous and Northern Affairs Canada, Public Services and Procurement Canada and Health Canada. This includes HBMs such as asbestos, lead, mercury, arsenic, mould and other biologic hazards, polychlorinated biphenyl (PCBs), silica and ozone depleting substances (ODSs).

Approach/Activities. Any project involving a building includes HBMs. The approach of the presentation is to share experiences and lessons learned from the typical lifecycle of a building project, including: preparation of the scope of work; assessment; quantification and cost estimation; specification authoring; tendering and construction phase services including contractor oversight; and, project closure.

In preparing the scope of work, clearly defining the ultimate goal of the project is a must. Understanding the limitations of the scope of work is also important. It is common that the scope of work will state that all HBMs are to be identified, however that is not typically possible. Understanding the limitations of both the scope of work for a project, as well as any consultant/contractor proposal and how the project goal is addressed is key to project success. There is no clear guideline on how to conduct a HBM assessment and assessment reports are highly variable in quality and thoroughness and this will drastically affect the ability to cost a potential project. The National Master Specification (NMS) format is a common specification used for HBM projects involving construction/demolition, however the NMS format is not universal to meeting Provincial regulatory requirements with respect to local labour and waste disposal. Specifications can be highly contentious and there are a number of ways an NMS specification can be interpreted which affects the success of the construction phase services including the need for a consultant to provide oversight and confirmatory sampling.

Results/Lessons Learned. Identifying the important HBMs to a project, how they will be assessed and the key components of an assessment report will be discussed. The presentation will walk the audience through the key steps of a HBM project, identifying key learnings based on actual projects compiled for various Federal departments. The key learnings and issues will be presented through the viewpoint of a consulting professional with 20 years experience working with Federal Departments to solve their HBMs challenges.

Site Access and Logistical Challenges Associated with the Remediation of Nottingham Island
Guillaume Robert, Englobe Corp.
The objective of this presentation is  to showcase the logistical and access challenges associated with remote arctic site remediation projects such as Nottingham Island, NU.

Nottingham Island, the former site of a Ministry of Transportation Weather Station, is located in the Hudson Strait, off the northwest coast of the Ungava Peninsula, Quebec and south of the Foxe Peninsula, Baffin Island, Nunavut. The island has been uninhabited since the 1970s, and the closest communities are Ivujivik, located 80 km to the south in Nunavik, and Cape Dorset, located 140 km to the north in Nunavut. Established in 1884, the weather station was operational for 86 years and was subsequently decommissioned in 1970. A radio transmitter was erected at the site in 1927 to provide navigational and weather information to ships in order to open the Hudson strait for shipping. Nottingham was one of three sites used as an aerial base for the first aerial mapping/photography survey of the Hudson Strait conducted by the Royal Canadian Air Force.

The remediation project involved the demolition of all site buildings and infrastructure, the onsite treatment of over 7,000 m3 of hydrocarbon contaminated soil, excavation and shipment south of 800 m3 of metal contaminated soil and the removal and southern disposal of roughly 1,000 m3 of hazardous materials originating from site buildings. The northern climate posed significant challenges to biological treatment of the soils, while the remoteness of the site posed significant logistical challenges. In contrast to most northern remediation projects, the site lacked any form of airstrip and therefore required a helicopter for crew rotation and resupply, which posed challenges due to the location of the island – in the open ocean and the prevalence of fog in the Hudson Strait. Initial mobilization and demobilization was performed by sealift, but since the site lacked a suitable natural harbour, sealift providers were required to anchor unprotected several kilometres offshore and contend with high swells and passing sea ice.

Pilot Scale Assessment of Lead Abatement Approaches for Reduction of Dissolved Lead in Water
Heather Lord, Samantha Clay and Taras (Terry) Obal
Maxxam Analytics
The objective of this presentation is  to describe the results of laboratory batch testing of several common and emerging treatment solutions for reducing dissolved lead in surface water.

Numerous amendments have been proposed for the abatement of heavy metal contamination in environmental waters. Site objectives often target reduction of the dissolved metal concentration in order to reduce bioavailability and uptake by plant and animal receptors. Adsorption can be an effective approach, followed by either sedimentation or filtration. Selection of an appropriate amendment can however be challenging. Typically cost, efficacy and avoidance of inadvertent environmental impacts of the amendment process must be considered. Preliminary batch testing is often required due to the significant site variability that can be encountered. We conducted laboratory batch testing of water from storm water retention ponds (ca. 250,000 m3 total) having a lead level of 1,000 µg/L and pH between 3 and 4, with >97% of measured lead in the dissolved form. The objective was to reduce the dissolved lead concentration to 15 µg/L and neutralize the pH.

Ten amendment approaches were evaluated including chemical reagents to sequester lead by precipitation and several media as well as native site fill for adsorption. Chemical reagents included sulphide, sulphate, carbonate and phosphate. Media included alum, lime, activated charcoal, hydroxyl apatite and kinetic degradation fluxion (KDF) resin. All amendments were loaded at a 3:1 molar excess. Batch testing was conducted in 500 mL amber bottles at 20 °C for four weeks. Bottles were shaken daily and agitated on a bottle roller at a 50% duty cycle. Four approaches – carbonate, hydroxyapatite, KDF – provided neutralization of the water to between pH 6 and 8 however only hydroxyapatite met the target lead reduction, achieving sub µg/L dissolved lead by 15 days. The presentation will provide the complete study results as well as share relative costs, potential for site impacts and considerations for practical site application.

Remediation of Hazardous Soil at a Defence Establishment in Southeastern Ontario
Tiffany Wong1, Scott Thompson1, Eric Kelly2, Edward Lloyd2, Chris Mcrae3 and Andrew Tam3
1Public Services and Procurement Canada
2SNC-Lavalin Inc.
3Department of National Defence
The objective of this presentation is  to show that proper planning and a prescribed soil delineation and excavation approach are key elements in successful execution of a remediation program implemented under tight time constraints.

Public Services and Procurement Canada, on behalf of the Department of National Defence, retained services to assess and administrate soil remediation of two areas of environmental concern (AECs) identified at a defence establishment in southeastern Ontario. The two AECs included in the remediation are identified as:
• AEC 3: leachate hazardous classified soil and dense non-aqueous phase liquid chlorinated hydrocarbons (dichlorobenzenes) in the soil overburden; and,
• AEC 4: non-hazardous, arsenic-contaminated surficial soil partially overlapping AEC 3.

A detailed grid-based soil delineation program was implemented in the vicinity of AECs 3 and 4 to refine the lateral and vertical extent of hazardous and non-hazardous soils with the overall objective of reducing typical scheduling and cost implications associated with verifying extents/quantities during remediation. A very well defined excavation model was developed from this approach.

Remedial activity implementation had to accommodate several site restrictions including working in an “active” defence establishment, which mandated additional controls for security and safety (e.g., stockpile height restrictions, limiting exposure of hazardous soils to workers and the public, security overwatch and site procedural requirements).

The work also coincided with an adjacent large-scale construction project which constrained the scheduling of project related tasks (e.g., breaking 800 tonnes of concrete for recycling and discharge of 702,000 L of treated groundwater).

Furthermore, due to operations and the adjacent construction project, the available space was restricted to an area of 7,710 m2; within which, the space encompassed a 2,290 m2 excavation (advanced 4 m bgs to bedrock), 3,900 m3 of clean soil stockpiles, a groundwater dewatering and treatment system including 450,000L of tankage, hauling entrance/egress ramps, decontamination pad and support trailers.

The remediation plan comprised a detailed lift-based grid excavation process. Each grid block was represented by a soil core whose length comprised an excavation lift. Based on this process, the excavation was pre-determined and staged instead of relying on sampling and analysis throughout. This had a number of benefits to the overall project implementation.
Live-loading of 1,700 tonnes of hazardous and 6,300 tonnes of non-hazardous soils based on the soil classification in each grid cell for off-site disposal at an appropriate facility mitigated health and safety concerns (i.e., direct exposure time to hazardous soils), reduced tracking of soil throughout the property and allowed efficient use of the limited foot print available, all minimizing disruption to base operations.
Pre-determined verification soil samples were collected at the anticipated excavation margins and, once confirmed they satisfied the applicable site conditions standards, the excavation was backfilled, compacted and the area was paved. Overall, the original excavation footprint was extended in in only two locations based on verification analytical results. This increased the overall waste generated by 400 tonnes of additional non-hazardous soil, only a 5% increase on estimate which is an impressive performance indicator for an ex-situ soil remediation project.
This approach allowed a compressed time frame for implementation. On-site remedial activities commenced on October 12 and were completed on December 8, comprising 42 working days, which included significant other activities such was installing, operating and decommissioning a groundwater dewatering system with a water treatment unit, instating a geosynthetic clay liner, backfilling, compacting and paving for site closure. It enabled ~80 trucks/day to enter the site. Furthermore, the costs associated with the time spent on-site was substantially reduced and outweighed potential risk/costs associated with the decision making process during remediation.

Planning and stakeholder commitment to the plan was necessary to undertake the work successfully. The grid-based delineation, dewatering and lift excavation approach implemented during the program were key elements to facilitate this rapid and efficient remediation program.

Three Case Studies: Using High Resolution Site Characterization for Better Remedial Design and Implementation
Patrick O'Neill, Vertex Environmental Inc.
The objective of this presentation is  to provide information and examples of how high-resolution site characterization tools can be used on all types of sites for remediation and site closure purposes.

Good decisions can be made with good data. Remediation programs that fail usually cite a lack of thorough understanding of the subsurface. Contaminant distribution can be complex and traditional sampling techniques may result in high variability and large data gaps. In-situ high-resolution site characterization (HRSC) is becoming a key component of site understanding and subsequent decisions being made regarding remediation and site closure. HRSC, as part of a Phase II Environmental Site Assessment (ESA), can greatly enhance the understanding of the presence, concentration and distribution of contaminants in the subsurface.

Three high-resolution characterization technologies commonly used in Canada to enhance Phase II ESAs include the membrane interface probe (MIP) for dissolved phase volatile organic compounds (VOC) contamination, the laser-induced fluorescence (LIF) probe for free-phase petroleum hydrocarbon (PHC) contamination, and the hydraulic profiling tool (HPT) for measuring the subsurface permeability and ultimately estimating the hydraulic conductivity of the subsurface. All three probes are advanced to depth by direct push methods (i.e., geoprobe).

These technologies can significantly enhance the understanding of the subsurface and associated impacts. Gathering thousands of points of data on a centimetre scale in a day, the HRSC tools can rapidly horizontally and vertically delineate environmental impacts. The data can be rendered in 3D to visualize the supplement conceptual site models (CSMs) and optimize remedial designs for individual sites.

This poster will showcase the various HRSC tools and how they helped facilitate remediation programs at different sites in Canada. The first site utilized the LIF to better understand residual LNAPL on an active remediation site utilizing multi-phase extraction and in-situ chemical oxidation technologies. The second site utilized the MIP to delineate a large and complex dissolved phase plume and optimize an in-situ chemical oxidation program. The final site utilized the HPT to estimate hydraulic conductivity in the overburden for a funnel and gate permeable reactive barrier (PRB) design and installation.

Per- and Polyfluoralkyl Substances: Navigating through Regulatory Uncertainty
Shalene Thomas, David Woodward and Nathan Hagelin
Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to provide a global picture of the emerging contaminant class, showcase what geographies are considered high priority based on current regulations, as well as what to consider to manage, mitigate and eliminate liability if you are currently using or have historically used PFAS.

Emerging contaminants have been defined as those chemicals or materials that have a perceived, potential, or real threat to human health or the environment, lack published health standards, and/or new source or pathway information has become available. Emerging contaminant programs were developed nearly a decade ago across the globe. Despite being around for almost ten years, emerging contaminants have not had elevated and extensive visibility until very recently with the momentum of contaminants such as 1,4-dioxane and per- and polyfluoroalkyl substances (PFASs).

If no promulgated health criteria are available, and the science surrounding these contaminants continues to evolve, how have they become such hot button liability issues globally? What key factors led us to where we are today and how will these factors influence the regulatory direction of future emerging contaminants? How do we navigate in such uncertainty to manage and reduce potential liabilities?

Key factors that have led us to where we are today. Using PFASs as an example, the history and timeline of regulatory, social, and litigious activity will be presented as well as the associated research progress, trends, and challenges that are arising as regulations continue to develop. An overview of the various international, federal and state emerging contaminants programs will be presented and regulations in the US, Canada, and Australia will be discussed in relation to their part in elevating PFASs to the priority status they currently have today.

What factors influence the direction of future emerging contaminants? Reactions to PFASs from government, industrial sector, and water authorities will be discussed. Proactive legislation at various state, federal, and international levels that ensures lines of liability are clearly defined will be presented.

How do we navigate in such uncertainty to manage and reduce potential liabilities? By performing a desktop liability evaluation, information can be generated for site managers to qualitatively forward-thinking programmatic infrastructure to support regulatory action will be highlighted.

What to take-away? Whether in industry, government or the private sector, emerging contaminants will continue to be defined for years to come and a programmatic evaluation of historical activities and current operations will successfully enable any organization to better prepare for and proactively manage the future evolution and liability of these dynamic group of chemicals.

Big Data and Mixed Reality: The Future of Conceptual Site Models has Arrived
Nick Welty1 and Jan Abbott2
2Arcadis Canada Inc.
The objective of this presentation is  to demonstrate how we can better understand site data by using newly developed technologies.

The next generation of the conceptual site model (CSM) is the big data, digital CSM, which continues the evolution in the industry from static to dynamic CSMs and 2D to 3D CSMs. The first generation of CSMs were sections in investigation reports – 2D static figures to illustrate key elements like geologic cross sections, groundwater flow maps, and contaminant contours. As high-resolution, smart characterization methods are becoming widely adopted, CSMs are more dynamic, requiring us to synthesize “big data” and develop 4D interpretations with more data than ever before. The CSM paradigm has shifted towards the digital CSM, which better leverages new tools for data mining, interpretation, synthesis and visualization.

One advantage is streamlined reporting: an investigation report typically requires dozens of 2D cross sections and plume maps, but the digital CSM allows the development of intelligent reports which require far less effort, through the application of multilayered 3D and 4D interpretations. Rather than flipping back and forth between figures and tables in a report, stakeholders can dynamically change the field of view, zooming in on details and evaluating the data behind the interpretation. Software solutions like dynamic PDFs and cloud-based, geographical information system team sites enable open access to the interpretations and the underlying data.

We will also demonstrate the next frontier in digital CSMs – mixed reality. Mixed reality enables one to combine a live view of the physical world with computer generated information – the data behind the interpretation. Rather than viewing a 3D model on a computer screen, one is able to interact with the information in a holographic image – from inside the rendering – changing the field of view with the wave of a hand, or selecting data behind the interpretation by selecting a boring log or sample location with a voice command or hand gesture.

Dioxin Degradation and Metals Biovolatilization at a Former Wood Treating Site
Leslie Hardy, Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to share the investigation results for a wood treating site that has been untouched for over 50 years. High concentrations of dioxins and metals have decreased due to natural attenuation.

A contamination assessment of a former wood treating site was completed in 2015. Work in the 1990s provided reliable results for a metal and chlorophenols ‘hot spot’ where sludge from the wood treating process was burned as a waste management practice from 1967 until 1970. The 2015 results confirm that dioxins, chlorophenols and metals are the main contaminants at the site, but significant natural attenuation of all contaminants has occurred since the site closed in 1970. These results are attributed to reductive dechlorination of dioxins and chlorophenols, and biovolatilization of metals.

The analytical results show a significant reduction in total dioxin mass, dioxin-TEQ and a change in the congener profile toward less chlorinated dioxins. The dioxin-TEQ half-life estimated based on 369 soil analyses since 2003 is approximately four years, and this is consistent with half lives presented in the literature for reductive dechlorination of dioxins.

Chlorophenols have continued to biodegrade along with the diesel fuel that was used as the carrier for pentachlorophenol (PCP). The PCP half-life in soil is approximately two years (289 samples from 1990-1993, and 353 samples from 2009-2015). The highest PCP concentrations were at ground surface which is consistent with the interpretation that anaerobic processes have reductively dechlorinated dioxins and chlorophenols.

Chromium, copper and arsenic (CCA) were used as the wood preservative prior to 1967 when the site switched to PCP. The molar ratio of these metals is fixed in CCA, but soil metals results showed mostly arsenic contamination. Arsenic was never used at the site except as CCA, and copper and chromium would have been initially present in the contaminated soil at concentrations reflecting the molar ratio in CCA.

The arsenic concentrations in soil have decreased since 1990, and this decrease cannot be attributed to groundwater transport or changes in soil analytical methods. The potential mass that could be removed by groundwater transport is far too low to account for the noted change in the soil metal concentrations. The earliest metals analytical methods are considered comparable to current standard methods. For example, the measured concentrations of copper and chromium in 2015 are very similar to the concentrations reported in the early 1990s. Metals concentrations measured in 2015 using a total acid digestion confirm that the concentrations measured using the standard metals digestion are representative of the total metals concentrations in soil.

The decrease in arsenic concentrations and the lack of chromium and copper contamination is attributed to biovolatilization which has been a known biogeochemical process for arsenic for over 100 years. The arsenic half-life based on 276 samples analyzed in 1990-1993, and 384 samples from 2009-2015 is approximately eight years. In the early 1990s, approximately 89% of the chromium and >95% of the copper was no longer measured in the soil when evaluated against the peak arsenic concentrations and the fixed molar ratio of metals initially present in CCA. The copper and chromium concentrations in soil are now largely at background levels.

Calculating Mass Flux Discharge to a Stream Using Natural Thermal Signals
Paul Martin, Nelson Molina Giraldo, Sarah Rampersaud, Alanna Dickson
Matrix Solutions Inc.
The objective of this presentation is  to illustrate a novel approach to estimating contaminant mass flux needed for risk assessment.

Assessment of risk to freshwater aquatic life requires estimation of the mass flux discharging to a surface water body or stream. While the integrated stream concentration that results from the cumulative zones of flow and mass discharge can be directly measured by taking stream samples for contaminants of concern, risk assessment requires additional characterization. Key questions include the spatial and temporal groundwater discharge that results in the integrated stream concentration (i.e., whether mass discharges uniformly or at discrete locations along the stream, and whether discharge is continuous through high and low flow periods, or limited to high flow periods). Direct measurements to achieve this characterization can be expensive and time-consuming; however one less-expensive indirect method that has been well established in the literature is the use of natural thermal signals.

Thermal signals in groundwater beneath a stream are relatively easy to measure and provide a means of calculating the time-varying local groundwater/surface water interaction based on diurnal and seasonal temperature fluctuations and their propagation into the subsurface. By having several locations of thermistor strings along the stream, both the spatial and temporal distributions of discharge flux can be estimated. This measure of groundwater flux can be combined with complementary measures of groundwater concentrations, surface water concentrations, and stream flow to evaluate the spatial and temporal mass flux discharge. This poster will present an application of an integrated groundwater/surface water monitoring system to estimate the spatial and temporal mass discharge to a local stream.

Conceptual Site Models for Per- and Polyfluoroalkyl Substances
Jeremy Piper, Krista Barfoot, Scott Grieco, William Diguiseppi
The objective of this presentation is  to serve as an aid in the investigation and delineation of contaminants at PFAS impacted sites, and to help identify potential data gaps in defining PFAS fate in the environment.

Per- and polyfluorinated substances (PFAS) related to aqueous film forming foams (AFFF) used to fight flammable liquid fires have been identified at various release sites as compounds of interest and are generally considered emerging contaminants due to their regulatory uncertainty. PFAS are the “active ingredient” in AFFF, which has been in common usage as a petroleum fire suppressant since the early 1970’s. PFAS contamination is thought to be present at fire fighter training areas, fire stations and related storage facilities, and at sites where petroleum fires were extinguished or suppressed using foam (truck and aircraft crashes, petroleum handling facilities, refineries and aircraft hangers). The strength of the carbon-fluorine bond, as well as the complexity of the AFFF mixtures, which can contain more than 1,000 individual PFAS compounds, contributes to their recalcitrance and difficulty in being adequately addressed. The mobility of individual PFAS compounds is poorly understood. As we begin to evaluate PFAS-contaminated sites, we need to develop conceptual site models (CSMs) to help guide the investigation and remediation.

A CSM approach was used to identify and organize the current thinking on PFAS behaviour in surface water and sediment systems to help investigators better understand issues related to PFAS storage and migration. A series of CSMs were created to depict how AFFF released from fire-fighting related activities can impact soil, groundwater, surface water and sediment and how the individual PFAS compounds in the AFFF can remain or migrate in the near surface system. The focus was on modes of release and potential chemical and geochemical transformations of the compounds. Data were extracted from the literature, as well as testing of various transformation processes on AFFF mixtures.

The models are intended to serve as an aid in the investigation and delineation of contaminants at PFAS-impacted sites, and to help identify potential data gaps in defining PFAS fate in the environment. PFAS are compounds that are generally resistant to sorption, biodegradation, and other destructive mechanisms that may be present in surface water and sediment, and therefore are expected to migrate freely in surface water. However, depending on the individual PFAS compounds present in the AFFF mixture, as well as the transformation processes that have occurred since the time of release, a fair amount of PFAS mass may be present in soil or sediments. This mass, may represent an ongoing source to groundwater or surface water contamination, and further transformation of some of these immobile compounds could release more mobile compounds (e.g., perfluorooctane sulfonate – PFOA, or perfluorooctanoic acid – PFOA), which are the most likely compounds to be regulated.

PFAS: Smart Characterization for an Emerging Contaminant
Patrick Curry1, Jennifer Son2, Seth Pitkin3, Joseph Quinnan1
1Arcadis US Inc.
2Arcadis Canada Inc.
3Cascade Technical Services
The objective of this presentation is  to describe and demonstrate an adaptive approach to PFAS characterization using high-resolution sampling and a first of its kind PFAS mobile laboratory.

The benefits of flux-based conceptual models derived from high-resolution site characterization are well understood for chlorinated solvents (CVOCs) and hydrocarbons – results indicate that more than 75% of contaminant discharge is focused in 5 to 10 percent of aquifers (Guilbeault, 2004). However, most practitioners are not aware that the approach can be used for emerging contaminants like per- and polyfluoroalkyl substances (PFAS). As a result, many are reverting to the use of monitoring wells and fixed laboratory analysis for investigating PFAS sites, rather than taking advantage of the latest developments in real-time, high-resolution site characterization. The introduction of a mobile laboratory capable of producing reliable PFAS results for soil and groundwater in hours instead of weeks has enabled us to conduct adaptive characterization at PFAS sites for the first time. When combined with high resolution injection logging methods like the WaterlooAPS and the hydraulic profiling tool (HPT), the Stratigraphic Flux approach can map PFAS impacts within a mass flux framework to identify key transport pathways that help focus extraction based remedies; currently the most likely option for PFAS risk management.

Using an adaptive approach for PFAS sites, we can streamline site evaluation and reduce the expensive step-wise process of planning, investigating and reporting. The mobile PFAS laboratory has enabled real-time analysis of PFAS including PFOS and PFOA. The laboratory uses a solid phase extraction sample prep technique followed by LC/MS/MS analyses that are based on EPA Method 537 (modified). The “PFAS Mobilab” is Department of Defense Environmental Laboratory Accreditation Program (ELAP) (QSM 5.1) compliant and National Environmental Laboratory Accreditation Program (NELAP) certified and can provide fully defensible and cost-effective soil and groundwater data within hours (as opposed to days or weeks) of sample collection.

To date, the PFAS mobile laboratory has been deployed at two sites with excellent results. Comparison of the mobile lab data to fixed laboratory results indicates good correlation. The mobile lab was able to process up to 20 groundwater samples per day, which was sufficient to guide two drilling rigs and eliminate wasted borings and samples. The ability to evaluate PFAS sites in real-time and at high-resolution has greatly enhanced our ability to efficiently characterize these sites using adaptive approach. This approach allows stakeholders to quickly understand the risk associated with this emerging issue, and to evaluate focused, efficient remedies - particularly important given the challenges associated with PFAS remediation.

Performance of In-situ Hydrogen Peroxide Injection to Remediate F2 PHC Contaminated Soil
Francis Galbraith1, Stefan Foy1, David Fursevich1, Chris Lach1, Jordan Stones2
1SNC-Lavalin Inc.
2Public Services and Procurement Canada
The objective of this presentation is  to outline the approach and performance of hydrogen peroxide injections for the in-situ remediation of hydrocarbon impacted soil at the maintenance camps.

An in-situ hydrogen peroxide injection program was designed and completed at the Muncho Lake and Fireside maintenance camps along the Alaska Highway. Soils at the maintenance camps (highway maintenance yards) had been impacted with F2 petroleum hydrocarbons (F2 PHC) from operation and maintenance activities stretching all the way back to the construction of the Alaska Highway. Both sites have a maintenance shop, salt storage shed, and residence(s).

Hydrocarbon peroxide injection was identified as the most promising approach to remediating hydrocarbon impacts in soils at depths that precluded remediation through excavation. Hydrocarbon impacts identified for remediation were generally observed in the smear zone at a depth of 7.5 to 11 m at Muncho Lake, and at depths greater than 8 m and associated with unsaturated soils, perched water tables, or the regional aquifer at Fireside. Hydrocarbon impacts at both sites at these depths were considered extensive and estimated to cover an area of 5,000 m2 at Muncho Lake and 8,400 m2 at Fireside. F2 PHC impacts were targeted for remediation, as this was the parameter that primarily exceeded applicable criteria.

The peroxide injection program pursued the following goals:
• Complete the injection of hydrogen peroxide in a representative target area to achieve a measurable reduction in F2 PHC concentrations;
• Collect data and develop methods that can be used for the optimal hydrogen peroxide application at the two maintenance camps during larger scale application; and,
• Confirm an approach and costs to make informed decisions with respect to a larger scale hydrogen peroxide remediation program at the sites.

The following activities were completed in 2017 as part of the hydrogen peroxide injection program:
• Determine pre-injection soil quality and hydrocarbon extents in target areas at both sites;
• Conduct a treatability study on soil samples to identify an appropriate application ratio for hydrogen peroxide and evaluation of various enhancements to hydrogen peroxide performance;
• Evaluate the zone of influence and in-situ effects during the injection of hydrogen peroxide;
• Inject hydrogen peroxide at an appropriate application ratio to achieve a reduction in hydrocarbons in soil within the target areas; and,
• Evaluate soil quality in the target areas following the injection of hydrogen peroxide

The results from the 2017 hydrogen peroxide injection program will be presented. Conclusions and considerations for additional hydrogen peroxide injections for the program will also be shared.

Surfactant Enhanced Extraction to Expedite Remediation of a Carbon Tetrachloride Source Zone at an Active Grain Elevator Facility
Eric Dulle1, John Hesemann1, George (Bud) Ivey2
1Burns & McDonnell
2Ivey International Inc.
The objective of this presentation is  to present enhanced method for chlorinated solvent soil and groundwater remediation using surfactant technology coupled with DPE.

Background/Objectives. The site is located in Kansas City, Kansas and currently operates as an active grain elevator facility. The site entered into the Voluntary Cleanup and Property Redevelopment Program (VCPRP) in 2000 following groundwater and soil detections of grain fumigant constituents of concern (COCs), including carbon tetrachloride (CT), in the vicinity of a former fumigant aboveground storage tank (AST). Following source area investigation and groundwater plume delineation activities, dual-phase vacuum extraction (DPVE) was implemented in 2007 for the removal of COCs in source area soils and groundwater. Groundwater is encountered at the site approximately 7 to 8 feet below ground surface (bgs). Lithology within the targeted source zone generally consists of well sorted, loose, silty-sand to depths ranging from approximately 13 to 17 feet bgs, underlain by silty clay.

After approximately six years of DPVE operation, resulting in the removal of over 9,000 pounds (lbs) of total VOCs, a subset of source area extraction wells continued to exhibit elevated COC groundwater concentrations. Additional investigation was conducted using high-resolution site characterization (HRSC) techniques to assess the nature and extent of residual COC mass in the source area and provide data required for the evaluation of alternatives that could expedite source area remediation. The investigation results indicated significant sorbed-phase COC mass, generally limited to the shallow, sandy interval of an area bound by the DPVE wells exhibiting elevated COC concentrations. Light non-aqueous phase liquid (LNAPL) heavily impacted with the site COCs was also identified. Surfactant enhanced extraction (SEE) was subsequently identified as the optimal source zone remedial alternative because of the technology’s ability to quickly and efficiently remove a concentrated, but relatively isolated and shallow zone of contaminant mass with relatively low surfactant application concentrations. In addition, the existing DPVE infrastructure could be utilized to implement SEE at the site, thereby minimizing cost and intrusive activities.

Approach/Activities. The contractor conducted a SEE pilot study at the site in April and May 2015 to evaluate the efficacy of the technology under site-specific conditions. The pilot study results indicated CT groundwater concentration reductions of up to 99%. Consequently, full-scale SEE was conducted in Fall 2016 to address remaining COC mass within the source zone. The full-scale SEE approach consisted of multiple phases, each consisting of point-to-point surfactant delivery to the core source area within the shallow saturated zone, followed by concurrent groundwater extraction (“pull”) events from the wells initially used for surfactant injection. This approach proved most effective in maximizing COC mass removal during the SEE pilot study.

Results/Lessons Learned. The pilot and full-scale SEE remedial efforts have resulted in the recovery of approximately 700 lbs of total VOCs, and CT groundwater concentrations in the source area have been reduced by 80% to 99%. Based on these results, permanent shutdown of the DPVE system is anticipated to occur in 2019, resulting in significant project life-cycle cost savings. The presentation will include the SEE basis of design, including the HRSC-refined conceptual site model, SEE design discussion, and key performance monitoring results and trend presentations.

Risk Assessment as a Tool to Guide Risk Management Decisions – A Case Study of Small Craft Harbours in Newfoundland and Labrador
Jody Berry1, Andrea Lundrigan1, Lisa Mcfarlane2, James Beresford3
1Wood - Environment and Infrastructure Solutions
2Public Services and Procurement Canada
3Fisheries and Oceans Canada
The objective of this presentation is  to discuss the current approach for sediment investigations and risk management for DFO Small Craft Harbours in Newfoundland and Labrador, and discuss two examples relevant to human and ecological health.

Small Craft Harbours (SCHs) is a nationwide program administered by Fisheries and Oceans Canada (DFO). The program operates and maintains a national system of harbours to provide commercial fish harvesters and other harbour users with safe and accessible facilities.

The Province of Newfoundland and Labrador has 339 active SCHs, many of which service remote communities along the coast and sediment investigations have been ongoing since 2001. These harbours have had commercial fishing activities for the past 120 years and have a variety of historical issues ranging from debris to contaminated sediment.

In 2017, a generic Tier 1 Scope of Work (SOW) for Marine Sediment Sampling Programs (MSSPs) in NL was developed in collaboration with DFO and Public Services and Procurement Canada to guide management decisions. These assessments were developed for a wide variety of sites with several different management goals including divestiture, provincial regulatory closure and federal scoring to determine priority for funding for future assessment and/or remediation. The MSSP SOW provides general guidance for first level assessment with the intention to collect sufficient data during one site visit for risk assessment. The information gathering portion of the MSSP SOW includes: a historical document review; interviews with representatives familiar with how the local community uses the waterlot and upland properties and surrounding area; and an initial site reconnaissance to identify potential sources of contamination and confirm proposed sampling locations. The field program includes a dive survey in which divers record bottom substrate conditions and aquatic habitat, and collect photographic and video footage of the benthic communities at each sampling location. Divers collect marine sediment samples for chemistry analysis and gather other lines of evidence including bulk sediment samples for benthic community assessment and tissue samples for chemistry analysis for bioaccumulating/biomagnifying contaminants of potential concern (COPC). Samples are strategically collected from waterlot and reference locations following a combination of targeted and grid-based (30-50 m spacing) design. A weight of evidence approach is conducted for the waterlot to understand if further (Tier 2) assessment is required or if risk characterization can be conducted with the data acquired from the site.

Based on the historical investigations, 46 Class 1 waterlots were identified in the NL region. The MSSP SOW has been conducted for 26 waterlots during the 2017-2018 fiscal year. Three different examples of management objectives will be presented. Firstly the Ferryland SCH, which is a candidate for divestiture. The Tier 1 assessment indicted a potential risk to human health and the results of the Tier 1 and 2 assessments will be presented with emphasis on potential divestiture. Secondly, the Port au Choix SCH, which is an active SCH and will remain with DFO for the foreseeable future. The Tier 1 assessment indicated a potential ecological risk and the findings of the Tier 1 and 2 assessments will be shared. Thirdly, an overview of how data collected for the 2017-2018 program can be used for future investigations and management decisions will be provided.

Completing a Detailed Quantitative Risk Assessment at a Sensitive Site with Multiple Federal Stakeholders: An Exercise in Collaborative Communication
Susan Pfister1, Cindy Smith1, Jody Berry1, Lynn Kumita2, Randi Grant3, Jennifer Sifton3
1Wood - Environment and Infrastructure Solutions
2Public Services and Procurement Canada
3Fisheries and Oceans Canada
The objective of this presentation is  to discuss the collaborative communication approach utilized with several federal agencies, including Public Services and Procurement Canada, Fisheries and Oceans Canada, Parks Canada, Environment Canada and Health Canada to support the completion of an environmental site assessment investigation and risk assessment.

Fisheries and Oceans Canada (DFO) is the custodian of many contaminated sites listed in Federal Contaminated Sites Inventory (FCSI) due to the nature of DFO’s property holdings. DFO’s properties include a variety of navigational markers, small craft harbours, and lightstations situated along watercourses, and often with interest from multiple stakeholders. They have often been present for long periods given their association with navigation and wayfinding. A common concern present at lightstations is lead-based paint resulting in trace metals, primarily lead, accumulating in soils. At many sites, risk assessment (RA) has been adopted to facilitate selection of appropriate risk management and/or remediation methods, where required.

The Grenadier Minor Shore Light, located within the Thousand Islands National Park, is one location where risk assessment/risk management (RA/RM) is in the process of being implemented. This presentation will showcase a case study which highlights the importance of engaging early with real property managers, custodians, and other stakeholders, including Federal Contaminated Sites Action Plan (FCSAP) expert support and departments with interests in contaminated sites, when completing FCSAP assessment work.

Federal real property managers, custodians, and consultants can facilitate successful projects through early involvement and communication with stakeholders. A collaborative approach to risk assessment requires early engagement and a comprehensive understanding of the risk assessment field activities, the timing requirements thereof, and practical working conditions. Collaboration improves work planning and implementation strategies around notifications and permitting. In instances where remote site access is a complication to coordination and completion of field activities, the need for clear communication is imperative to provide value to the Crown for each mobilization to site. Open communication with FCSAP expert support departments early in the project facilitates best practices in data collection and promotes the application of current standards and practices. Discussions pertaining to key components of the risk assessment (e.g., receptors, dose averaging, exposure characteristics, and exposure pathway choices) also aids in the completion of the risk assessment.

Aspects of this project where collaboration and communication assisted in project progression included: submission of the draft problem formulation report to Health Canada (HC) and Environment Canada, DFO, and Public Services and Procurement Canada (PSPC) prior to proceeding with the detailed quantitative RA; discussions with HC on the benefits of conducting bioaccessibility testing for lead; coordination of field events with DFO/PSPC and Parks Canada (Parks); working with Parks to ensure appropriate considerations and mitigation measures were taken to protect a species at risk (SAR) plant and critical habitat present in the area during field activities; and, working with Parks to expedite obtaining access agreements by providing early and accurate description of field activities and mitigative measures to be used by the consultant (and subcontractors).

Evaluation of Bis(2-ethylhexyl) pthalate (DEHP) Exceedance in Sanitary Effluent and in Groundwater
Lovina Pereira1, Jamal Azzeh1, Stewart Arnott1, Yousry Hamdy2
1Arcadis Canada Inc.
The objective of this presentation is  to provide knowledge and understanding of exceedance of Bis(2-ethylhexyl) pthalate in sanitary effluent and ground water.

Bis(2-ethylhexyl) phthalate, also known as di(2-ethylhexyl) phthalate (DEHP), is a widely used phthalate plasticizer. DEHP is used in polyvinyl chloride (PVC) products to increase flexibility. It is also used in the manufacturing of paint, undercoating, flooring and many other plastic products. DEHP does not chemically bind to plastic polymers and can easily become dispersed from these products. Environment Canada reported that DEHP is not only released from its manufacturers and industrial users but is also released from plastic products. DEHP is a toxic substance listed under the Priority Substances List (PSL).

DEHP is detected in many various facilities and in monitoring wells; however, it is typically reported as false positive due to contamination from sampling tubing, sampling errors, and/or lab errors. Recently, DEHP has been identified in sanitary effluents at concentrations that exceed local municipal bylaw limits and in ground water samples obtained from industrial/commercial (federal) properties. The primary objective of the study is to determine the sources of DEHP in both sanitary effluents and in ground water at properties that otherwise do not contain sources of DEHP.

Various methods were used to determine the sources of DEHP including a chemical inventory at the study location; in addition, a bench scale study is being conducted to determine leaching of DEHP from PVC pipes or well casing into sanitary effluent and ground water, respectively. The impact of the contaminants of concern (e.g., hydraulic fluids, gasoline, glycol) that may potentially impact the leaching of DEHP of PVC products was also studied. Contamination from sampling equipment as a source of DEHP is also being evaluated as a potential source for DEHP exceedances. Preliminary results show that various sampling equipment (e.g., plastic tubing, bailer, etc.) may be contributing to the presence of DEHP in both the sanitary effluent and ground water samples, but are not the only source of DEHP. Further bench scale studies will be carried out to confirm the potential sources of DEHP and methods to mitigate them. In addition, treatment technologies and their applicability will be evaluated for sanitary effluent and groundwater.

Assessing the Vulnerability of Drinking Water Supplies at Canadian Forces Bases Across Canada
Steve Usher1, Robert Till1, Ted Hergel1, Darin Burr2, Debbie Nicholls3
1SLR Consulting (Canada) Ltd.
2Dillon Consulting Limited
3Department of National Defence
The objective of this presentation is  to discuss the key considerations in doing vulnerability assessments at Federal sites, outline the steps taken and provide examples from completed studies.

Source water protection has increasingly become a concern for custodians of Federal sites. Health Canada has published generic guidelines for protecting drinking water and some Provinces (i.e., Ontario) have developed a prescriptive framework for assessing vulnerability and protecting drinking water supplies. This project furthers the existing processes for assessing and protecting water supplies by adopting best practices to develop and apply a framework applicable to Federal sites.

Water supplies at Canadian Forces Bases are a combination of groundwater wells, surface water intakes, and uniquely, desalinization facilities. Land use and military activities present a variety of low- and high-risk potential contaminants of concern. Individual activities include both point sources such as fuel storage or small waste disposal sites, as well as diffuse sources such as munitions ranges or firefighting training areas. Risk management of these issues requires a prioritized framework, and thus an understanding of the setting, hydrogeology, hydrology and the potential issues is of paramount importance.

The Department of National Defense has commissioned a series of vulnerability assessments, followed by source water protection plans at their sites across Canada. Each study includes several key steps. First the physical setting of the subject site is established including the geology, hydrogeology, surface water and physiographic setting through a conceptual model. The water sources and uses are then inventoried including all groundwater wells and surface water intakes. The zones of capture for the wells are determined and a wellhead protection area (WHPA) established for each. Intake protection zones (IPZ) are established for surface water intakes.

The next step is to identify the contaminants of concern, the amounts and their locations, their mobility in the ground and surface water and their risk in relation to the water sources. A wide range of potential contaminants must be considered including metals, inorganics, nutrients, PFAS/PFC, energetics, hydrocarbons and other organic compounds. Once this is established, an assessment of relative risk to the various water sources is compiled and monitoring and priority assessment programs are recommended. The nature of the aerially extensive bases is such that there are multiple point and diffuse sources of contaminants of concern, and multiple water sources to consider.

This presentation gives the key considerations in doing vulnerability assessments of these water supplies. It outlines the steps taken and provides examples from completed studies to date. Consideration of the different regulatory requirements across the country are discussed. The intent of the presentation is to demonstrate that the principles learned from various jurisdictions for both broad source water protection and for focused individual contaminated site assessment can be successfully applied to provide a rigorous and considered approach to safe water supply.

Assessment of Naturally Elevated Background Trace Elements on a Regional Scale for Application to Sites on the Alaska Highway, Northern BC
William Culloch Dasson1, Alan Walker1, Ryan Hill1, Rae-Ann Sharp2
1SNC-Lavalin Inc.
2Public Services and Procurement Canada
The objective of this presentation is  to present the approach and results of a background evaluation for trace elements identified along the Alaska Highway.

The Alaska Highway is located in Northern BC and is under federal custodianship. Eventually, the highway and associated properties may be returned to provincial jurisdiction. Evaluation and reduction of environmental liability is an on-going process for these properties. Historically, the focus of the liability reduction has been on contaminants confirmed to be of anthropogenic origin, such as petroleum hydrocarbons. The general practice of including a broad suite of ‘metals’ as a generic potential contaminant of concern (PCOC) for preliminary assessments of sites with evidence of historical anthropogenic activities has resulted in regulatory exceedances for several trace elements (TE) that have no recognized sources at the sites. It has been recognized that there are some naturally occurring TE present in soil and groundwater at concentrations exceeding applicable federal and provincial numerical screening criteria. There have been few attempts at conducting delineation programs for TE, since there is little evidence for anthropogenic sources and occurrences of exceedances appear to be irregular between sites over wide areas, leading to an assumption that they represent natural conditions. Both federal and provincial approaches to contaminated sites provide for local assessment of background conditions.

Anthropogenic impacts of TE were anticipated to be present for some TE, and therefore enriched relative to background. An enrichment factor (EF) was used to estimate if TE were enriched at sites with a relatively high potential of anthropogenic effects. The EF compares the ratios of the potentially enriched TE to a conservative TE in both a sample and in a background dataset. The dataset of all TE on Alaska Highway sites was screened initially against the provincial regional numerical criteria presented in Protocol 4. Natural enrichment would be expected in a geologically heterogeneous terrain in a wide area dataset and a wide range of EF values were identified. Therefore, a TE in a sample was assessed for potential anthropogenic enrichment if its EF was anomalously high (i.e., outlier). Results indicated that several TE were considered anthropogenic; however, several outliers were considered to likely represent naturally anomalous conditions.

Once the cases of anthropogenic influence were identified using the EF approach, they were excluded from the data set, and the remaining data were assumed to represent ‘natural’ conditions. The data were then analyzed statistically to evaluate the upper limit of natural concentrations for key trace elements. Several potential explanatory variables were considered that could be expected to affect trace element concentrations, including site location, land use, sample depth (upper/lower rooting zones and subsoil), approximate grain size percentage, and geomorphic setting.

Assessing Petroleum Hydrocarbons in High Natural Organic and High Moisture Content Soils: 5 Wing Goose Bay
David Rae, Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to highlight the challenges in determining contaminant concentrations in high organic and high moisture soils and to provide an example approach for assessing petroleum hydrocarbons in peat soils at 5 Wing Goose Bay.

Applying the Canadian Council of Ministers of the Environment (CCME) Canada Wide Standards (CWS) for Petroleum Hydrocarbons (PHCs) to non-mineral peat soils with high natural organic content and high moisture content can result in unnecessary remediation and waste of taxpayer dollars.

CWS-PHC were developed for the protection of ecological and human health, based on four PHC fractions and for coarse- or fine-grained mineral soils. Difficulties arise when CWS-PHC are applied to non-mineral peat soils. High natural organic content results in analytical interference from biogenic PHCs (i.e., not related to petroleum fuel impacts) making it problematic to correctly identify petrogenic PHCs in the sample. High moisture content affects laboratory reporting of results which, by convention, is on a dry weight basis, resulting in false positive results in soils with high moisture content.

The method to correct results for biogenic PHCs incorporates concepts in CWS-PHC and relies on establishing the chemistry of the fuel source and clean reference peat. PHC fraction ratios are calculated for clean peat samples to establish the naturally occurring biogenic PHC profile. For any contaminated peat sample, biogenic PHCs are calculated based on the ratios and the biogenic concentrations are subtracted from the laboratory reported concentrations to leave only petrogenic contributions to PHCs. To counter the effects of high soil moisture, all sample results are normalized to a single moisture content. This provides a consistent basis for comparison of results to guidelines and between samples with widely varying moisture contents.

An example of these approaches is provided at 5 Wing Goose Bay. Survival Tank Farm (STF) occupies an area of approximately 1 km2, east of the main Base. STF was used for bulk storage of PHCs such as avgas and diesel with a storage capacity of 80,000,000 L. All infrastructure has been removed and the site is now used for recreational activities (e.g., all-terrain vehicles). STF is underlain by both sand (tank lots) and peat impacted by PHCs. Peat samples collected downgradient of the tank lots have fundamentally different properties to sand soils and contain up to 40-50% organic carbon, with 80-95% moisture content. Laboratory results suggest widespread F3 contamination (>CWS-PHC) in peat downgradient of tank lots however the correction approach shows petrogenic F3 concentrations in peat do not exceed CWS-PHC. Remediation areas at STF are significantly reduced.

Correctly interpreting PHC concentrations in high organic and high moisture content soils realizes significant environmental benefit through avoidance of unnecessary remediation and destruction of clean, organic-rich habitats.

Moving Beyond Criteria-Based Remediation
Ian Mitchell, Millennium EMS Solutions Ltd.
The objective of this presentation is  to demonstrate how non-standard approaches can address the potential for adverse effects from contamination while improving overall environmental outcomes and reducing costs.

At many contaminated sites, remediation decisions are based on concentrations of contaminants exceeding numerical criteria such as CCME soil and water quality guidelines. However, exceeding generic or even site-specific criteria does not always mean an adverse effect is present now or in the future. However, remediation is itself associated with adverse effects. For example, remediation equipment and the trucking of soil results in greenhouse gas emissions; work in natural settings causes ecosystem destruction and disturbance of wildlife; trucking of soils can lead to traffic accidents; and, injuries or even fatalities have occurred due to health and safety incidents on remediation projects.

Due to the adverse effects of remediation, this means that in some cases remediation to numerical criteria has a net negative outcome for the environment and human health.

For large or complex sites, or for sites in sensitive environmental settings, it may be appropriate to use the numerical criteria as a screening tool. However before moving on to remediation, other approaches including ecological effects assessments and mass-based transport modelling can refine the assessment of risk. Even at small sites, using simple tools to assess the potential for adverse effects may indicate that no remediation is necessary.

Terrestrial ecosystem function assessments have been used successfully at several contaminated sites in forested ecosystems to demonstrate that, even though concentrations of contaminants in soil exceed numerical criteria based on the protection of plants and soil invertebrates, actual plant growth was either not significantly affected or the system was recovering on its own, and therefore any aggressive remediation would cause more harm than benefit. The effects-based assessment saved considerable amounts of money as well as shortening the time to closure.

Similarly, at several sites in native prairie ecosystems similar approaches have been applied. The development of these approaches was initially spurred by a grazing leaseholder who didn't want to see quality grazing land disrupted to address contamination having no apparent effect. Over a portfolio of similar sites, several million dollars in remediation costs were saved by applying these methods combined with other more traditional risk-based approaches.

Ecosystem function assessments can also be applied in aquatic systems; the Sediment Quality Triad approach is well accepted in Canada and has been successfully applied at several federal contaminated sites with contaminants exceeding sediment guidelines in lake or stream sediments.

Another approach is to utilize 3D groundwater transport modelling based on the actual distribution of contaminant mass. Criteria-based approaches fundamentally assume that contaminant concentrations are homogeneous. More advanced modelling approaches allow for a more realistic treatment of contaminant mass, as well as evaluation of scenarios such as targeted removal of contaminant mass driven by factors other than just concentration (e.g., accessibility, or presence of co-contaminants).

Numerical criteria, both generic and site-specific, remain important tools for addressing contaminated sites. However, they are not the only tools available, and in many cases other approaches can not only reduce costs but also result in a better environmental outcome.

The Use of Drone Technology in Landfill Cell Construction and Other Environmental Applications
Kyle Press, Eric Draycott, Jon Dimascio
Arcadis Canada Inc.
The objective of this presentation is  to demonstrate the use of drone technology on large construction sites to effectively make a traditional activity more accurate and efficient.

This presentation will illustrate the use of this technology to facilitate construction of a new landfill cell in eastern Ontario. A state of the art M210 Drone and Topcon GPS system has been deployed that can fly pre-destined routes calibrated over the active construction area. The drone will be equipped to take data points every 1 cm over the footprint of the active area, versus 5-10 m used in traditional surveying methods. This data capture will allow our construction teams to achieve more accurate survey volumes and cell elevations in minutes and process raw data from the drone in hours compared to weekly turnarounds from third party surveying companies. The on-demand processed data will allows us to make ‘real-time’ decisions as construction proceeds, provide quicker back-up for invoicing and surveying requests by our clients, and streamline our day to day – week to week planning of construction activities. The drone can fly in rain, cold and moderate winds as well as can capture mapping, lidar and thermal imagery. The drone provides a mechanism to collect data in areas which would otherwise be inaccessible by foot as well as survey highly contaminated areas reducing the need to enter manually. Highlights from other select applications will also be presented.

Groundwater Treatment of Petroleum Hydrocarbon Contaminated Sites in Remote Northern First Nations using an Innovative Portable Water Filtration System
Julieta Werner1, Tara Chisholm1, Lina Letiecq1, Kerri Hurley1, Andre Legault2
1Indigenous and Northern Affairs Canada
2Activated White
The objective of this presentation is  to evaluate the effectiveness of innovative technology in clean up efforts at petroleum hydrocarbon contaminated sites in Northern First Nation Sites.

Contaminated sites projects in Northern Ontario regularly require the treatment of large quantities of impacted soil and groundwater, which results in the construction of large biocell treatment facilities and the need to treat groundwater at the site. Once treated, concentrations of contaminants, especially hydrocarbons, are high enough to need disposal of treated groundwater in the community sewage lagoons, which creates an additional strains on these lagoons. In addition, large quantities of consumables are stored on-site until they can be either removed from the site via winter roads or disposed of at the community refuse site. Commercially available groundwater treatment systems currently used in Northern Ontario projects are usually fuelled using diesel generators, which require the transportation and use of additional fuel in the community.

Through the Build in Canada Innovation Program (BCIP) an innovative and sustainable portable water filtration system was tested at one remote First Nation Community. Eabametoong First Nation, located approximately 360 km north of Thunder Bay, Ontario, is a remote community that can only be accessed by scheduled flights and by winter road, if weather permits. Petroleum hydrocarbon contaminated soil and groundwater was identified at seven sites within the community. Remedial options considered for the sites included the excavation and disposal of contaminated soil as well as the treatment of contaminated groundwater. Based on preliminary calculations, approximately 75,000 L of contaminated groundwater would need to be treated prior to discharge onto the First Nations sewage lagoon.

Following excavation of impacted soil, all seeped groundwater was pumped out of the excavation area and treated either with the commercially available granular activated carbon (GAC) system or the BCIP innovation. The BCIP innovation consisted of four filters containing an advanced polymer capable of binding hydrocarbons more effectively than commercially available GAC systems. In addition, a hydrosense monitor was added to the fourth system that was capable of providing real-time hydrocarbon concentrations in the treated water. The filter material is made of biodegradable material that can be safely discarded at the community’s landfill site, resulting in less disposable materials needed to be removed from the community. The BCIP system has the capability to handle large volumes of water (up to 1,300 L of water per hour per cell) resulting in remediation projects being completed in less time which is key in project areas where construction season is relatively short.

The use of this system was also an opportunity to reduce greenhouse gas emissions as the BCIP technology allowed for the use of a 1,000 W generator instead of a diesel generator, making this treatment system more sustainable for the environment.

During remediation work at Eabametoong First Nation, groundwater samples were collected from the excavation area prior to entering the systems to determine the concentrations of petroleum hydrocarbons prior to treatment, after the oil/water separator and prior to discharge. All samples were submitted to a CALA certified laboratory for analysis, and the results tabulated for comparison. A comparative assessment of the two technologies was completed to evaluate cost, efficiency, ease of use in a remote setting, treatment capabilities, and sustainability factors. The results will be used to determine the suitability of the deployment of this technology at other remote petroleum contaminated sites in the Department of Indigenous Service’s portfolio.

Plume Stability Analyses and Role Within LNAPL Management Framework
Matthew Michaelis, Wood - Environment and Infrastructure Solutions
The objective of this presentation is  to discuss the processes for conducting a plume stability analysis and to discuss the role of the analysis within an LNAPL Management Framework.

Light non-aqueous phase liquid (LNAPL) assessment and remediation has historically presented a great challenge for environmental practitioners and site custodians. The presence of an LNAPL body in the subsurface may present acute and/or long-term risks to human and/or ecological receptors. However, even in scenarios where risks to receptors are demonstrated as being absent, regulations often require that all LNAPL be recovered from the subsurface. Such regulatory requirements have been problematic to overcome as complete LNAPL recovery often proves to be impractical. For such scenarios where a risk-based driver for remediation does not exist, the industry is beginning to shift toward the implementation of LNAPL Management Frameworks in order to achieve conditional site closures with low frequency, long-term monitoring plans.

An LNAPL Management Framework is a sustainable risk-based LNAPL management strategy that examines whether any receptors are currently being impacted or are likely to be impacted in the future. The stability and recoverability of the LNAPL body and the extent to which natural attenuation is occurring are also evaluated. The implementation of an LNAPL Management Framework is not only more practical than complete removal of an LNAPL body, but also provides the benefits of reduced remedial timelines and reduced costs when compared to a traditional remedial approach.

Technical guidance for applying an LNAPL Management Framework prescribes a multiple lines of evidence approach demonstrating that the LNAPL body is either stable or diminishing. One of the primary lines of evidence for demonstrating LNAPL body stability is a stability analysis of the associated dissolved phase plume that examines statistical trends in the overall plume area, average contaminant concentration, contaminant mass and plume center of mass over time. Examining these trends allows for an evaluation of the plume as a holistic entity providing a thorough understanding of the stability of the entire plume.

Groundwater and fluid level data has been collected quarterly since the first quarter of 2014 at a site in Atlantic Canada where an LNAPL body and dissolved phase plume are present in the subsurface. Underground storage tanks (USTs) were removed from the site in 2001. Upon removal, petroleum hydrocarbons were observed within the excavation and impacted soil was removed from the site. In 2004, a Phase II Environmental Site Assessment (ESA) was completed and reported free product in several monitoring wells. An LNAPL removal system was installed and operated from 2008 through 2014, removing over 100,000 L of product; however, recovery rates eventually plateaued and operation of the system was discontinued. The monitoring programs conducted following system shutdown have demonstrated that free product is still present in several monitoring wells. The quarterly data being collected has been incorporated into updates to an ongoing dissolved phase plume stability analysis with the end-goal of demonstrating stability of the dissolved phase plume and associated LNAPL body to be used to support site closure.

Challenges of Iron in Groundwater Remediation Projects – A Case Study
Jason Downey, Newterra Inc.
The objective of this presentation is  to share the challenges and experiences of dealing with iron on a groundwater on a brownfields risk management implementation.

Naturally occurring iron in the dissolved form is commonly found in groundwater across North America. This seemingly harmless compound can lead to a number of challenges for environmental engineers working to remediate properties with groundwater contamination where dissolved iron is present.

Iron in the dissolved form will readily convert to a rust coloured precipitate called iron oxide when exposed to air in recovery wells, pneumatic pumps, vacuum extraction process lines, air strippers and tanks. Iron oxide particles are typically in the range of 0.5 micron to 2 micron and can bind up to form larger particles. Once in the oxidized form, iron will settle and plug piping, tanks, reinjection wells, carbon filters, air strippers and bag filters, which result in ongoing operating and maintenance challenges and operating cost overruns.

The discharge of iron-impacted water is highly regulated in most regions. This is primarily due to the oxidation potential of dissolved iron, which consumes oxygen from rivers and streams, as well as the increased turbidity, and sedimentation of precipitated iron. The increasingly stringent regulations for iron-impacted water require remediation engineers to remove the iron prior to discharge in many applications.

Working with a team of environmental consultants, the presenter experienced these challenges first hand on a brownfield redevelopment site in Belleville, Ontario. On this site, groundwater levels are monitored and controlled to prevent the flow of contaminated groundwater off the property.

A case study on this project will be presented outlining the challenges found on this site, the process followed to qualify and quantify the iron problems, and the steps taken to narrow down the best treatment solution. In addition, the case study will describe the technology chosen to manage the iron problems on the project.

By sharing the challenges, method of technology selection, and lessons learned delegates would be able to apply this experience to their own water treatment challenges and build upon the experiences shared.

In-situ Bioremediation of RDX Contaminated Soil and Groundwater at a Former Military Demolition Range: Degradation, Ecotoxicological and Genomics Aspects
Louis-B. Jugnia1, Dominic Manno1, Sabine Dodard1, Charles Greer1 and Meghan Hendry2
1National Research Council Canada
2Department of National Defence
The objective of this presentation is  to present an in-situ treatment approach using a carbon amendment (waste glycerol) surficially applied to enhance remediation of RDX contaminated soil and groundwater.

The effect of a carbon amendment (waste glycerol) on RDX (hexahydro-1,3,5- trinitro-1,3,5-triazine) biodegradation was assessed during a pilot-scale study at a former military demolition range (Grn Petawawa, ON). As a large-scale in-situ treatment approach, waste glycerol was surficially applied to a suspected RDX soil hotspot and the soil and groundwater were monitored over time to assess treatment effectiveness by determining residual RDX concentration, bacterial population dynamics using genomics and ecological impacts using ecotoxicological assays. Results indicated that RDX biodegradation by indigenous anaerobic microorganisms was improved with the carbon amendment, such that no RDX was detected in soil samples collected from the treated area and there was a large decrease in RDX concentration in four of the five groundwater monitoring wells, with the concentration being reduced to below detection limits in three wells. All three RDX nitroso-degradation metabolites were detected in groundwater samples, indicating the presence of an anaerobic degradation pathway. Genomics analysis of groundwater samples revealed diverse but different bacteria from the treated/contaminated (Geobacter, Clostridium Sulfuricurvum and Klebsiella), non-treated/uncontaminated control (Bacteroidales and Alphaproteobacteria) and non-treated/contaminated control (Nitrospirales). Variable results were obtained for toxicity tests on different receptor organisms (bacteria, algae, Daphnia, earthworms and plants) with an overall indication that waste glycerol should be applied at low concentrations, since high concentration had adverse effect on some of these organisms. These results offer good prospects for the use of carbon amendment approaches in addressing the bioremediation of energetics (e.g., RDX) contaminated sites.

Review of Hazards, Risks, and Regulations for Tug and Barge Vessels on Sediment Dredging Projects
Doug McMillan, SNC-Lavalin Inc.
The objective of this presentation is  to highlight the importance of regulatory requirements for tug and barge best practises.

Sediment investigations and remediation in both marine and freshwater environments require the use of a variety of equipment, vessels and watercraft. Operating vessels and equipment in harbours and waterways come with additional risks and hazards to safety and infrastructure including allisions and collisions. The operation of vessels and equipment for water based projects also fall under a different suite of regulations, requirements, and best practices. For this presentation, a review of equipment and vessels typically used for sediment remediation projects will be shared. The applicable regulatory requirements, industry standards, best management practices, and safety procedures for managing water-based projects will also be presented. Finally, several case studies of documented incidents and their lessons learned will be shared.

Thermal Desorption for Remote Site Soil Remediation - Using Enhanced Thermal Conduction for the Remediation of a Mineral Exploration Legacy Site in the Yukon Territory
Chad Belenky, Iron Creek Group Inc.
The objective   will highlight the versatility of the enhanced thermal conduction process as a cost effective addition to the remediation practitioner’s toolbox, along with lessons learned from deploying the technology to this unique and remote project location.

Enhanced thermal conduction (ETC) technology was successfully utilized on a mineral exploration legacy site located in an extremely remote area of the Yukon Territory, Canada. This unique site is located in mountainous terrain, approximately 250 kilometers from the nearest village and can only be accessed by air via a 1,100’ backcountry airstrip. Approximately 2,000 tonne of diesel impacted soil was treated with a modified version of the ETC equipment that was custom built to fit in a de Havilland Twin Otter aircraft in order to be deployed to this location.

Soil impacts at the site were a result of a historical diesel fuel storage tank release and were characterized by BTEX parameters as well as LEPH10-19 (Light Extractable Petroleum Hydrocarbons) and HEPH19-32 (Heavy Extractable Petroleum Hydrocarbons) all exceeding territorial contaminated sites criteria. In some portions of the impacted soil, initial diesel range organics concentrations exceeding 22,000 mg/kg were identified. A broad range of soil types and soil moisture contents were processed during this project ranging from tight clays saturated to field capacity to wet fluvial material and even some discontinuous permafrost material. Work was completed during the frost-free summer months with heavy rainfall and extreme weather occurring routinely throughout the project. Closure sampling and analysis that was conducted following the thermal treatment process resulted in all samples meeting the territorial contaminated sites regulation requiring extractable hydrocarbon levels below 1,000 mg/kg for each of the LEPH10-19and HEPH19-32 fractions. Following remediation, the clean, thermally treated soil was used to backfill the excavation area to facilitate successful reclamation of the site.

Brownfield Redevelopment of Former Public Works Yard, Winnipeg, MB
Doug Bell1, Kate O'neil1, Keith Merkel2
1Dillon Consulting Limited
2EdgeCorp Developments Ltd.
The objective of this presentation is to present an overview of a brownfield project that involved a unique partnering of the City of Winnipeg and a private developer to undertake the redevelopment of a former City of Winnipeg impacted property.

The Park City Commons Joint Venture retained services to assist in developing an environmental management plan (EMP) for the redevelopment of a brownfield site at 1500 Plessis Road in Winnipeg, Manitoba. The joint venture was an initiative between a private developer and the City of Winnipeg. The site – formerly the Transcona Public Works Yard operated by the City of Winnipeg – was historically used for vehicle maintenance and fuelling related to fleet management. The site also included two vehicle fuelling underground storage tanks (USTs) and served as the main outdoor storage facility for road salt and sand for the City of Winnipeg. A prior environmental site assessment for the site indicated a significant quantity of salt-impacted soils with an associated remedial cost estimate of approximately $6 million. However, an innovative approach was taken to address the road salt and fuel-related hydrocarbon impacts by applying risk assessment and management approaches in conjunction with more traditional soil remediation practices.

The assessment and remedial planning was completed with support from the Federation of Canadian Municipalities Green Municipal Fund financial incentive program. This program supports site remediation or risk management approaches in order to bring a brownfield site back into economically productive use.

The outdoor storage of the roadside salt piles over time resulted in leaching of the salt and consequent salt impacts in the shallow soils on site. The approach incorporated a risk assessment/management strategy to address the human health and ecological concerns for the residual impacts at the site. The resulting remedial action plan (RAP) for the salt-impacted soils included the implementation of a clean fill cap and selective planting of more salt-tolerant tree and shrub species. It was also recommended that corrosion inhibitors be use for any pre-stressed concrete that would be exposed to chlorides from deicing salt, that new hard surfaces (i.e., buildings and paved surfaces) be constructed to reduce potential adverse effects to off-site ecological receptors via generation of wind-blown soil particulates, and that that salt-impacted fill material below and adjacent to foundation structures be excavated and removed from the area.

The soils surrounding the fuel UST sites required remediation and removal of the hydrocarbon-impacted soils. A RAP for both UST sites was prepared and included the removal of the tanks and the excavation of impacted soils to be disposed of off-site. Additionally, there were other potential petroleum hydrocarbon impacts associated with the hydraulic system and floor drains in a maintenance building on the site. This impacted soil was also excavated and removed off-site for disposal.

The risk management and remediation strategy proved to be a very cost effective and practical means to remediate this site. Working with the joint venture developer around the planning and design of the buildings and infrastructure for the redevelopment allowed the majority of the salt impacts to be managed on-site, while the fuel-related contaminated soil was removed for off-site disposal. Ultimately, this innovated approach reduced the overall costs to manage the salt impacts to significantly less than $1 million.

Selenium Treatment in Solid Matrices Using Zero Valent Iron
Scott Grieco, Jacobs
The objective of this presentation is to demonstrate treatment of selenium in solids that provide permenance for disposal.

Increasingly, as regulatory limits become more stringent, selenium has become a parameter of concern. Selenium is a naturally occurring element that is largely mobilized by anthropogenic activity such as mining for fuel and subsequent combustion, metal ore refining and processing, and agricultural irrigation. Of concern is immobilizing it within leachable solid matrices. Chemical reduction and stabilization using zero valent iron (ZVI) is for immobilization when applied in an aqueous-mediated reaction. The treatment is an aqueous mediate reaction and promotes a stable solid matrix of non-leachable selenium.

This presentation outlines the chemistry of ZVI treatment, and key variables applicable to stabilization of a solid matrix. Data from a case study with a solid matrix treatment application are provided. The case study is applicable to matrices such as sediments, ash ponds, and industrial bag house dust solids. The presentation describes matrix challenges and the most important parameters within that effected successful treatment. The study demonstrates the permeance of treatment (via chemical reduction) after simulated disposal conditions.

Lessons Learned from a Multiple Waste Stream Remediation and Landfill Capping Project in a Sensitive Arctic Environment – Former Iqaluit Military Dump
Ryan Janzen1, Stephen Livingstone2, Ryan Fletcher1
1Arcadis Canada Inc.
2GeoCentric Environmental Inc.
The objective of this presentation is to recount the successful remediation program and lessons learned for the Iqaluit Community Metal Dump.

The Iqaluit Former Metal Dump/Community Landfill is located at the West 40 area on the border of Sylvia Grinnell Territorial Park and the Sylvia Grinnell River, 1.7 km southwest of the City of Iqaluit. The United States Air Force (USAF) used the site from between 1955 to 1963 as a metal dump for vehicles, truck bodies, barrels and scrap metal. The majority of the materials were deposited in 1963 when the US Military left Frobisher Bay. Shops, buildings, and other materials were simply bulldozed over the cliff or pushed into open surface water channels. The cliff is a bedrock outcrop rising approximately 30 m above the tidal area where the Sylvia Grinnell River meets Frobisher Bay. The Sylvia Grinnell River is a sensitive arctic char ecological zone. The site covers an area of approximately 72,500 m2. Environmental investigations carried out at the site identified the presence and impacts of petroleum hydrocarbons (PHCs), inorganic elements, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCB) contamination in soils, surface water and sediments. Debris quantification and a designated substances building survey were also undertaken which identified a significant amount of hazardous and non-hazardous wastes.

A $6M multi-waste stream, landfill waste cell construction and capping remedial program was fast tracked in the summer of 2017. The activities consisted of hazardous and non-hazardous waste identification and sorting of debris (including within active surface water areas); sediment extraction and soil sorting and management, with material selected to be incorporated into the waste cell or diverted to other treatment areas or facilities locally or transported south via sealift. The large landfill zone was capped requiring the construction of an access road and over 40,000 m3 of construction specific aggregate. The work was completed near and within sensitive surface water and arctic permafrost environments.

This presentation provides an analysis and evaluation of the lessons learned in managing a large scale diversion of multiple waste streams in sensitive environments to ensure risks to human health and the environment from the site conditions during and after remedial work are negligible.

Frequently Asked Questions about the Precursors to Perfluoroalkyl Acids
Jinxia Liu and Sampriti Chaudhuri
Department of Civil Engineering and Applied Mechanics, McGill University
The objective of this presentation is to shed some light onto the commonly asked questions regarding this new class of compounds in aqueous fire fighting foams formulations, as well as provide a summary of noteworthy details on the occurrence, analytical challenges, interactions with co-contaminants, transformation potential, and possible remediation strategy options available for pre-perfluoroalkyl acids.

Polyfluorinated surfactants present in aqueous fire fighting foams (AFFF) formulations are an integral part of the family of PFASs (per- and polyfluoroalkyl substances), which have high chemical stability and environmental persistence owing to the perfluoroalkyl moieties[F(CF2)n–]. They have been in use for a myriad of applications, causing global detection in humans, wildlife and the environment, especially the highly persistent compound PFOS (perfluorooctane sulfonic acid). Along with occurrence of PFAAs (perfluoroalkyl acids) primarily PFSAs (perfluorosulfonic acids), PFCAs (perfluorocarboxylic acids), and FTSAs (fluorotelomer sulfonic acids), the complexity of AFFF formulations has increased manifold by the recent identification of more than 100 fluorinated surfactants with various hydrocarbon functionalities, referred to as “precursors” to PFAAs (or pre-PFAA). These precursors have the potential to degrade to PFAAs in the environment. They occur as amphoteric, cationic, anionic and zwitter-ionic fluorinated surfactants, and can therefore exhibit properties and consequentially environmental behaviours that might be very different from traditional PFAAs.

The environmental persistence and effects of pre-PFAAs are predominantly unknown, and they could most likely pose as long term sources to PFOS and other polyfluorinated compounds. Fate and transport of other contaminants such as TCE and petroleum hydrocarbons may be strongly linked to the presence of these highly surface-active pre-PFAAs, but little is being investigated. Additionally, bioremediation or in-situ chemical oxidation targeting other contaminants may cause unintended accelerated transformation of pre-PFAAs into PFAAs. Due to their status as commercial proprietary information, the occurrence of pre-PFAAs has been rarely investigated.

To shed some light onto the commonly asked questions regarding this new class of compounds in AFFF formulations, this presentation highlights a summary of noteworthy details on the occurrence, analytical challenges, interactions with co-contaminants, transformation potential, and possible remediation strategy options available for pre-PFAAs.

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