Former Camp Ipperwash is located the western shores of Lake Huron in Lambton Shores, Ontario. From 1942 until 1995, Camp Ipperwash was utilized by the Department of National Defence (DND) as a military training ground. Training activities included infantry training, artillery training, mortar training, anti-tank weapons training and grenade training. As a result of these training activities, there are significant issues related to unexploded ordnance (UXO) at the site. In addition, the site also has a long history of use by First Nations, and accordingly, there are also significant cultural artifacts present at the site, as well as the presence of plant and animal species at risk (SAR) throughout the site.

Defence Construction Canada, on behalf of DND, retained services to conduct a Phase II Environmental Site Assessment (ESA) at the site utilizing a multi-disciplinary team consisting environmental, UXO, archaeological, and SAR (biologist) professionals. The multi-disciplinary approach allowed for the avoidance of UXOs, the identification of cultural artifacts, and the identification and avoidance of SAR throughout the work areas prior to the collection of environmental soil, sediment and groundwater samples.

The Phase II environmental site assessment involved the advancement of boreholes, installation of monitoring wells, and the collection of surface soil and surface water samples. The key contaminants at the site included energetic compounds, metals, dioxins and furans, volatile organic compounds, petroleum hydrocarbons and polycyclic aromatic hydrocarbons.

The results of the Phase II ESA will be utilized by DND to develop a scope of work for the further delineation of soil, sediment, surface water and groundwater impacts identified at the site. Those impacts include metals, energetics, dioxins/furans, and polycyclic aromatic hydrocarbons. Energetics are those compounds utilized as propellants or as the explosive components of military ordnance. Energetic compounds can survive intact in the environment after the partial detonation of the ordnance, and can then break down into their component elements, including metals. These contaminants are a concern in Canada due to the number of current and former military training grounds where these types of contaminants may be found.

The purpose of this presentation will be to discuss the process utilized to conduct the Phase II ESA activities as supported by the UXO, cultural, and SAR teams, and to discuss how the emerging contaminant of UXO energetics is assessed and the implications of that work for future activities at the site.

Traditional sampling practices for groundwater, such as the low flow and purge-based sampling, require the management of investigation derived waste (storage and disposal of purge water) and sampling equipment (e.g., bailers, hose, peristaltic, bladder and submersible pumps). Passive samplers designed to sample groundwater without pumping or purging are capable of replacing traditional sampling practices without the loss of data quality and generation of nearly zero waste during the sampling process. Since the passive samplers need less equipment, logistics, and manpower to collect samples, the passive samplers are an ideal green choice for the remote sites.

Studies have shown that most monitoring wells receive groundwater flow through the well screen interval. Groundwater in the well screen interval is in equilibrium with the adjacent groundwater (formation quality water) and suitable for sampling by the passive sampler. However, not all groundwater is thoroughly mixed, and in equilibrium with the formation water, careful consideration of target analytes, sampling objectives, hydrogeological conditions, well screen length, and sample volume requirements is required to deploy the passive samplers at a site successfully.

An evaluation matrix that considers site conditions (hydrogeology, well screen depth and length, and groundwater level), laboratory sample volume requirements, target analytes and data quality objectives and sampling device characteristics were developed to screen the passive sampling technologies and select the preferred passive sampler for the site. Further, groundwater sampling was conducted at selected locations using the preferred passive sampler (HydraSleeve) along with the traditional sampling technique (low-flow sampling) to determine the sampler specific variability and validate the evaluation matrix.

A comparative cost analysis was completed in the final phase of the study to evaluate the cost-effectiveness of passive sampling when compared with traditional sampling techniques. The results of the comparative cost analysis indicated that the passive sampling eliminated the cost of mobilizing, setting up, and dismantling equipment at each well location as well as minimizing purged water that often disposed of as waste.

In summary, the study showed 99% reduction in waste water generation and 100% reduction in the compressor or generator fuel use. The results of the study also showed that conversion to passive sampling techniques from traditional methods was unlikely to impact long-term site management strategies and likely to reduce total energy use, greenhouse gas emissions, material use, and waste generation.

The former Giant Mine, now under the control of Indigenous and Northern Affairs Canada (INAC) on behalf of the Federal Government, is one of Canada’s largest contaminated sites. A key component of mine closure is to backfill underground voids to prevent collapse of portions of the mine that could pose immediate risks to public and worker safety and lead to failure elsewhere. In the case of the Giant Mine site, there is the additional risk that underground collapse could allow surface water to flood the mine eventually. Severe environmental consequences could result from such a flooding event due to the presence of arsenic trioxide dust in the underground stopes. To mitigate risks related to underground stability at the mine site, an innovative short-term advanced remediation backfilling program is underway, while the long-term overall remedial plan for the site continues to be developed.

INAC engineers working with Public Services and Procurement Canada, along with industry leaders in mine closure, developed an innovative assessment technique using a drone to view the condition of a series of stopes in order to support the development of a mitigation plan for backfilling. An efficient approach to stabilising the underground voids using tailings paste backfill and self-levelling concrete was developed. Paste backfill is commonly used in operating mines to maximise production, but its use in mine mitigation and remediation is limited. The Giant Mine project team utilised thousands of tonnes of tailings that had been deposited on the surface as a waste by-product during historical production mining as the primary component of the backfill required to stabilise this complex series of voids. It is cost-effective to use on-site tailings material for underground backfilling, but its use also reduces the future effort required to remediate surface tailings pond areas. It was also determined from these drone assessments that part of this stope complex would require stabilization using a more durable self-supporting plug of concrete to help maximize the longevity and durability of the mitigation effort.

Aquatic assessments at federal sites with a long history of contamination issues (e.g., abandoned mines, northern military sites), and large infrastructure projects (e.g., hydro-electric dams), frequently struggle with high uncertainty resulting from an incomplete understanding of baseline and historical environmental conditions. This uncertainty can complicate decisions on the appropriate level of remediation for these systems. Furthermore, the determination of background concentrations of naturally occurring substances is important when adverse biological effects have been predicted using Sediment Quality Guidelines (SQGs) (i.e., measured chemical concentrations at a site are >SQG). Although natural levels of chemicals may have an adverse effect on certain organisms, the Canadian SQGs for the Protection of Aquatic Life suggests that the evaluators consider the contribution of natural processes in order to focus on the sites and chemicals that are primarily influenced by human activities.

Sediments represent a rich archive of information on current and historical conditions in aquatic ecosystems. Over time, remains from organisms that have inhabited the system are deposited to and incorporated into the sediment record. Similarly, metals and organics tend to persist in sediments. The paleolimnological approach exploits these sediment properties to reconstruct past environmental conditions through the use of sediment cores. Using radiometric-dating techniques, it is possible to assign dates to the various layers of sediments within a sediment core. As a result, biological communities (e.g., diatoms, chironomids) and chemical composition in different sediment layers can be used to infer conditions at the time of deposition. As a result, the use of sediment cores can be used to reconstruct natural baseline (pre-contamination) conditions, identify the presence of contaminants, and track historical trends. Furthermore, by coupling biological and contaminant data, it is possible to quantify impacts resulting from contaminants, and even track recovery of systems following cessation of operations and remediation. As such, paleolimnological investigations can provide a cost-effective alternative to long-term monitoring programs, and provide defensible data in which to identify background environmental conditions.

This presentation provides two case studies which demonstrate the utility of these techniques for reconstructing past conditions at aquatic sites influenced by anthropogenic activities.

Obtaining analytical data during remediation activities represents a significant cost for most projects. In addition to the direct costs for the analytical data, there are associated costs from equipment standby time, over digging, and resampling due to the delay between when data is needed and when it becomes available. A technological solution to this problem is the use of short wave infrared (SWIR) reflectance spectroscopy to obtain near real-time data in the field. SWIR reflectance spectroscopy measures light absorption for specific chemical bonds, which allows it to identify distinct spectral signatures for petroleum hydrocarbons (PHCs) in soil. By using innovative machine learning models, SWIR spectra obtained in the field can be transformed into quantitative measurements of multiple contaminants.

In August 2017, the field application of this technology began with Parks Canada as part of the Build in Canada Innovation Program. Samples were collected and analyzed at 14 sites at multiple locations in Canada including: Jasper, Banff, Kluane, and Riding Mountain National Parks along with Historic Sites in Quebec. At each site, 15 soil samples were collected. Samples were analyzed by reflectance spectroscopy, and then submitted to an accredited, third party laboratory for analysis using the Canada wide Standard for Petroleum Hydrocarbons in Soil (PHC CWS). Wider SWIR analyses were performed at each site to build data-density for three-dimensional modeling.

Overall, the R2 values for the F2 to F4 PHCs were above 0.98. The majority of F1 PHC measurements were near the detection limit of our technology (65 ppm), which limited representative comparison. The average prediction error for the F1 PHCs was 61 ppm, followed by 302 ppm for F2 PHCs, 809 ppm for F3 PHCs, and 209 for F4 PHCs. The false positive rate for this analysis was 3% and the false negative rate was 2% across the entire program. Data analysis time, from initial concentration measurements to the output of 3D models, varied with data volumes. Sites with few data points (<100) took less than a minute while sites with higher data collection (>2,000) took up to 10 minutes.

This study shows that accurate SWIR analysis of PHCs in soil is possible and, with the automation of data processing, can deliver significant timesavings. This translates to the potential for significant cost savings on remediation projects through reduced analytical costs, standby time, over digging, and resampling. Additionally, the data can be integrated with automated data visualization systems to produce vertical profiles and two-dimensional or three-dimensional spatial analyses.

Drums left behind at former military sites, meth labs and unauthorized storage facilities may contain multiple contaminants that, if spilled or disposed of inappropriately, could adversely affect human health and the environment. Depending on the physical and chemical characteristics, contaminants may separate into aqueous and non-aqueous phases. Rainwater infiltration into corroded containers can mix with drum contents and induce phase liquid separation. This can make the aqueous phase liquid layer appear clearer and can visually mask thin, heavier, and more toxic non-aqueous liquids that reside near the bottom of containers. Mixing drums with unknown contents could result in chemical reactions that may lead to the formation of toxic, flammable or explosive by-products. Consequently, aqueous and non-aqueous phase liquids can represent different levels of physical and chemical hazards. As such, following a predefined protocol that determines the contents of phase separated liquids in abandoned drums can help facilitate safe disposal of hazardous wastes.

Indigenous and Northern Affairs Canada has adopted an abandoned military site remediation protocol that it uses for the clean-up of its northern remote sites. One of the sub-protocols in this remediation protocol is the Distant Early Warning (DEW) line clean-up barrel protocol that specifies inspection, sampling, testing and disposal criteria for abandoned drums. The DEW line clean-up barrel protocol permits one to classify organic or aqueous liquids by analyzing samples for glycols, alcohols, polychlorinated biphenyls PCBs, chlorine and select metals (cadmium, chromium and lead) to identify the appropriate waste stream disposal processes. The DEW line clean-up barrel protocol has been successfully used to remediate remote former military sites. In emergency response situations where a release is imminent or has occurred, the DEW line clean-up barrel protocol can be used to quickly and efficiently determine the presence of unknown aqueous and non-aqueous phase liquids and to characterize the hidden physical and chemical hazards associated with those substances.

This presentation focuses on an emergency response case study done in 2016 where waste handling contractors were assisted in the waste characterization of materials found aboard a derelict barge in the Mamquam Blind Channel in Squamish, British Columbia. Numerous drums, bilge water and debris were encountered in different holds of the derelict barge during the emergency response. Once the derelict barge was safely secured, the materials were transferred from the derelict ship onto a supporting barge. The application of the DEW line clean-up barrel protocol enabled the classification of contents in the drums and the contents of the holds of the ship into solid, sludge, and liquid waste streams within a short time. Health and safety and waste tracking from the derelict barge to the permitted facility proved to be the two most challenging aspects. This presentation showcases the versatility of the DEW line clean-up barrel protocol and how it can be applied in emergency response situations when rapid assessment is necessary.

Modelling tools are well established for simulation of flow and contaminant transport through porous media; however limitations arise when applying such tools to simulate conditions in fractured rock environments. Two key differences between analysis of transport through unconsolidated porous media and discretely fractured rock are: 1) the potential for high velocity transport along discrete fracture pathways; and, 2) the process of matrix diffusion. This presentation will focus on conditions in sedimentary rock environments, which are commonly characterized as having: 1) frequent fracturing providing secondary porosity within which most groundwater flow occurs; and, 2) a bedrock matrix providing primary porosity where flow is negligible, but the contaminant storage capacity is significant.

While high velocity flow is frequently observed along individual fractures (micro-scale), flow through the interconnected fractured network (macro-scale) is often much slower as a result of the tortuosity introduced by the network of fractures with apertures varying over orders of magnitude. Transport of contaminants is further retarded by matrix diffusion processes, which have the effect of transferring mass from fractures into the rock matrix. Within the rock matrix, the storage capacity is large and the retardation effect is further enhanced by sorption and degradation processes. Given the matrix porosity typically exceeds the fracture porosity by orders of magnitude in sedimentary bedrock systems, the potential amount of contaminant mass stored in the matrix can be significantly greater than that transported through the fracture network. This process has the effect of “retarding” plume migration, and in many cases can lead to steady-state plumes; decay or biodegradation can further enhance this retardation or even lead to shrinking plumes. This retardation effect has been observed to be non-linear and thus can be difficult to simulate using conventional modelling tools. The large mass storage in the matrix can also lead to long-term plume tailing due to slow back diffusion processes as source zones become depleted.

Tools available to predict contaminant fate and transport in fractured rock include the application of equivalent porous media (EPM) models, dual porosity/permeability models (DP/DK), and discrete fracture network-matrix (DFN-M) models. Each type of modelling tool has strengths and weaknesses that limit their practical application. Comparison to detailed field data indicates that the most appropriate approach involves combining the strengths of EPM and DFN-M modeling tools in an integrated manner. This approach uses EPM modeling to simulate the bulk flow system (macro-behaviour), and coupled DFN-M simulations along flow paths to simulate matrix diffusion and other key transport processes (micro-behaviour).

This presentation will highlight the limitations of applying each type of tool individually and demonstrate the benefits of the coupled EPM/DFN-M approach. This approach is particularly valuable for the evaluation of contaminants where the maximum concentration limit (MCL) is orders of magnitude lower than typical source concentrations.

Canada is a vast country with many remote and isolated communities and operations. Managing contaminated sites in these locations poses unique challenges. Many of them are situated in ecologically and/or culturally sensitive areas where damage to the ecosystem by traditional environmental site assessment equipment would be unacceptable.

High Resolution Site Characterization (HRSC) technology provides an excellent approach to remote site assessment with speed, real-time data processing, and high spatial resolution – all of which reduce the need for additional mobilizations by facilitating adaptive assessment strategies and producing high quality and high-density data sets. While the HRSC technology offers substantial cost and technical benefits compared to traditional sampling methodologies, remote and eco-sensitive sites can still be a challenge for its application due to the need for a direct push platform (i.e., drill rig) to deploy the technology.

The Environmental Sciences Group (ESG) partnered with several groups, including Parks Canada, to conduct a high-resolution site characterization investigation at Sable Island National Park Reserve, a remote and ecologically sensitive barrier island located 175 km offshore of eastern Canada. In order to realize the use of HRSC technology at the site a unique low impact mobile drill rig (LIMB DRIG), was designed and tested through a Natural Sciences and Engineering Research Council of Canada Engage Grant. The LIMB DRIG was designed to be i) hand assembled; ii) less than 150 pounds; iii) fit into a hockey bag; and, iv) deliver at least three tonnes of push force. The LIMB DRIG surpassed all design parameters allowing for the navigation of site terrain and transport on a small aircraft. The LIMB DRIG was also capable of delivering the Laser Induced Fluorescence (LIF) probe for in situ assessment of petroleum hydrocarbons in soil and groundwater using a hand operated gear drive system in combination with a dynamic hammer. The unique surficial geology of the assessment location, consisting of well sorted, homogenous sand, supported the development and use of this lightweight delivery system.
The application of the LIMB DRIG with the HRSC technology in an eco-sensitive and remote site was highly effective, producing a high volume of representative, diverse data in one mobilization. Additional applications with a modified LIMB DRIG are being pursued at other remote and sensitive sites.

Understanding the value and role of natural resources, its associated ecological services and quantification of functionality of ecosystems is of great importance as it facilitates the capability to provide balance between a “perceived need” to remediate contaminated sites and protection/restoration of the environment. Quantification of natural resources value is the link in determining appropriate mitigation measures or remediation strategies to compensate for environmental impacts resulting from the implementation of projects and/or to protect, maintain or restore ecosystems and biodiversity on contaminated sites.

A quantification methodology, called Habitat Equivalency Analysis (HEA), has been successfully applied to quantify the level of ecosystem services that are provided by the natural resources of a site for various types projects. Applications include:
• Quantification of ecological baseline conditions;
• Determination of “value” of ecosystem components and ecological services;
• Assessment of reduced ecological services as a result of project implementation or remediation activities;
• Potential habitat compensation, including Species at Risk habitat; and,
• Quantification of increased ecological services as a result of mitigation/reclamation activities over time.

The goal for contaminated sites management is to have a decision-making tool that allows the quantitative assessment of natural resources and the assessment of “cost” to those natural resources that may be incurred from remediation activities. “Costs” to ecosystems can include loss of habitat, including species at risk habitat, a decrease in biodiversity and loss or decrease in ecosystem services.

The decision to remediate or manage a contaminated site can be driven by the results of an ecological risk assessment. The use of HEA where hazard quotients are greater than 1 can help to evaluate which management options make sense for a given site. The use of the HEA with the risk assessment process provides a framework that will facilitate decisions for contaminated site management such as whether remediation or management is warranted and will improve the ecological function of a site, whether contamination can be left in place and monitoring be used to confirm lack of impact or whether a combination of remediation, management and monitoring is most appropriate for a given site.

Based on project examples, this presentation will focus on the key characteristics of successful use of appropriate HEA to support identification of baseline conditions, appropriate mitigation and restoration measures, and the various associated benefits of demonstrating net gain of biodiversity. It will also demonstrate how the HEA could be incorporated into the Contaminated Sites Framework to guide management decisions driven by ecological risk.