SMART Remediation’s Annual Toronto Conference, was held on February 28, 2013, and was a big success! The event featured industry leaders speaking about new technology and approaches for effective delineation and remediation of contaminated soil.
SMART Remediation Presentations for Toronto
Tony Powell P.Eng.
Tony Powell is the Applications Manager and one of the co-founders of Purifics ES Inc. He is a Professional Engineer (Chemical) from the University of Toronto and a member of the Professional Engineers of Ontario. He has over 20 years of experience fielding remediation solutions.
Tony has extensive experience in the application of Purifics’ unique technologies for remedial, industrial and municipal water applications. He works closely with his clients to ensure proper fit and function, while ensuring low life cycle cost.
Advanced Control Network to Treat Dissolved Metals, VOCs and 1,4-dioxane
A plume of contaminated groundwater originating from a former Landfill & a Drum Transfer Facility threats a Municipal Reservoir for two cities. A series of groundwater recovery wells pumping year round is used to control the plume hydraulically, preventing its spread into the surrounding area. The recovered groundwater along with landfill leachate is collected and contains heavy metals, chlorinated VOC’s, and 1,4-dioxane. In order to treat the water an elaborate phytoremediation system was implemented alongside a physical treatment system.
The phytoremediation system consisted of 2 acres of wetlands designed to breakdown the chlorinated VOC’s biologically. Water taken from the wetlands is then fed into a 30 acre stand of trees divided into 15 irrigation zones designed to remove 1,4-dioxane through phytovolatilization. Contaminated water is delivered to each irrigation zone based on the moisture content of the soil in that zone. Special attention is made to not over saturate the soil causing the contaminated water to percolate through the landfill soil cover and into the landfill itself. This is accomplished through monitoring using a network of moisture sensors throughout the irrigation zones providing zone-specific feedback to a master controller. An integrated weather station also provides additional information such as temperature, wind direction, and humidity. The master controller then uses mathematical algorithms to determine which zones to irrigate based on soil moisture content and real time weather conditions, and how much water to send. When the soil in a zone becomes saturated, irrigation to that zone is stopped and a new zone is irrigated.
Initially, a physical treatment system is used to treat the well water and landfill leachate until such a time where the phytoremediation system can take over. As the wetlands and tree stands develop over time, a greater portion of the water can be routed to them. In the long term, at times when the volume of water requiring treatment is greater than what the phytoremediation system can accept the excess water is routed to the physical treatment system which is automatically activated. This physical treatment system is composed of a CFFeR unit where iron and manganese are oxidized, settled, and filtered out without the use of chemicals; and a Photo-Cat system which destroys VOCs and 1,4-dioxane and any other remaining hydrocarbons. This paper discusses these systems in greater detail, and takes a close look at the monitoring and control network that has been integrated in order to treat the water efficiently and effectively. This includes the ability to monitor and control the system from remote locations via any computer or smartphone with internet access.
Cecile Willert, P.Eng., QPRA
Cecile Willert is a Professional Engineer (Civil) and a Senior Risk Assessment Specialist with EcoMetrix Incorporated. She has over 25 years of consulting experience encompassing risk assessment, risk management and site investigations. She has a proven track record of successfully seeing numerous highly complex and challenging contaminated sites through the risk assessment and approvals process in Ontario. She regularly conducts peer reviews of risk assessments and related studies for public and private sector clients including regulatory reviews as part of an approvals process. Landmark projects include: work as an environmental specialist providing expert review services for the West Don Lands development of the Pan Am Games Athletes Village in Toronto in an extensive area of historic contamination, risk assessment for a condominium development in the distillery district of Toronto (now constructed) on a former industrial site with extensive contamination including free phase coal tar, conduct of one of the largest risk assessments in Canada, undertaken in Port Colborne, Ontario for community wide metals contamination, risk assessment of the Toronto FILMPORT lands with extensive historic petroleum and metals contamination, assessment of the former Toronto Film Studios lands with free phase chlorinated solvents, and conduct of a community wide assessment in Smithville, Ontario, for free phase PCBs and various chlorinated solvents in bedrock. She has reviewed numerous risk assessments, environmental site assessments and records of site condition conducted under the newly revised Record of Site Condition Regulation in Ontario. Ms Willer co-chairs the Brownfield Committee for the Ontario Environment Industry Association and has been closely involved with processes to reform the Record of Site Condition Regulation (O.Reg. 153/04), the soil and groundwater standards and the risk assessment process in Ontario.
Case Studies in Risk Management Methods as a Component of the Remedial Process
While governments across North American release new guidance on assessment of vapour intrusion, and soil vapour sampling is becoming more the norm, these developing methods are complimented by methods for encapsulation, site or building design constraints and development of less stringent remediation target levels that are based on proven methods, and accepted by regulators. Example projects examined include approaches to risk assessment and management through design of buildings, design considerations for capping methods and considerations for vapour intrusion. Example projects for each are used to balance remediation to a practical extent with risk management and regulatory approvals.
The first case study will examine development on a former heavy industrial site with free phase organic contamination in fractured bedrock combined with organic and inorganic groundwater and soil contamination. The challenge was to construct the maximum number of levels of underground parking possible while not causing elevated risks associated with free product left in place in fractured bedrock. Only soils required for foundation excavation were removed and other soils were managed in place. The risk management plan included comprehensive health and safety requirements, detailed building design requirements and site capping to prevent direct human contact. Specific considerations in the building design included maximizing the number of levels of underground parking, minimizing disturbance of free phase product, minimizing the potential for seepage of groundwater and vapours into the building, and maximizing dilution potential of any vapours reaching the indoor environment. Ongoing monitoring systems were put in place to ensure that future groundwater seepage into the building did not adversely impact the indoor environment.
The second case study was a mixed use site with petroleum contamination combined with metals and impacts from road salt storage. The road salt caused exceedances of free phase thresholds and had to be addressed by combined remedial and risk assessment measures. Encapsulation of non-volatile compounds was required for delineated areas of the site. Soil vapour sampling was used to develop remedial target concentrations for volatile chemicals. This assessment considered the impact of remediation of overlying soils on potential vapours from deeper soils and groundwater. Remediation targets were set according to the results of the risk evaluation prior to commencing remedial work.
The third case study was an assessment undertaken for a commercial/industrial facility with a co-mingled solvent and petroleum product plume with both on-site and continuing off-site sources, making full remediation difficult to achieve. Possible risk management options were reviewed in the development of the selected alternatives and including an ongoing monitoring and maintenance plan.
Scott M.S. Barker, MBA, BScE
Scott Barker is Managing Director and a Principal at TOTERRA Remediation Ltd., based in Burlington, Ontario, Canada. He earned a Bachelor of Science Degree in Chemical Engineering, with a specialization in Biochemical and Environmental Engineering, at Queen’s University in Kingston, ON and a Master of Business Administration Degree at the Ivey School of Business, Western University. Scott has extensive experience in water treatment, chemical formulation, production, and distribution, and waste management and resource recovery. Prior to the establishment of TOTERRA, he held senior operational and leadership roles with Toyota Tsusho and Newalta Corp. His current focus is on expanding the delivery of TOTERRA’s soil conditioning, targeted amendment emplacement, and 3D subsurface mapping services in eastern Canada and the northeast U.S.
Using Environmental Fracturing In Low Permeability Soils And Bedrock
The effectiveness of commonly used in situ approaches to site remediation in North America, and indeed much of the world, can be seriously undermined by a site’s inherent lithology. As a result, site remediation practitioners around the world are increasingly turning to environmental fracturing as a means of increasing contact area in the subsurface; contact area in a “typical” fracture-enhanced well in low K soil is usually 600 to 1,000 times greater than that of a conventional well in the same soil. This presentation examines the evolution of environmental fracturing technologies to address these limitations and provides practitioners with a guide to the application of environmental fracturing, based on 17 years of project experience in jurisdictions ranging from across North America to Europe, Africa, and Asia.
Following an introduction of the technical history of, and the geotechnical and economic justification for, environmental fracturing, including a review of both hydraulic and pneumatic variations thereof, the presentation highlights a series of project “vignettes” from various environmental sectors (oil and gas, brownfield developers, superfund sites, etc) to showcase the integrated and synergistic use of innovative fracture-enhancement techniques for attaining sustainable and cost-effective remediation. Physical, biological and chemical (reductive and oxidative) treatment technologies are showcased in the context of both subsurface extraction and delivery techniques to optimize contact with contaminants for their conversion to innocuous and natural end products. Examples of remediation technologies in challenging geologic settings and operationally constrained sites are provided to showcase their versatility and small site profile.
Complimentary remedial verification tools are introduced to validate and confirm the effective treatment of subsurface soil and groundwater contaminants to achieve remedial goals. The implications of the application of environmental fracturing within the remediation industry are assessed in the context of cost benefits for site owners, efficacy gains for owners’ engineers, and enhancing environmental sustainability for communities.
Ms. Dooley has over twenty five years experience in many aspects of environmental industry including project management, research and development, senior technical oversight, remedial design and laboratory management. Ms. Dooley’s current position is the Northeast Region Manager for Regenesis. She is responsible for managing both sales and technical support associated with Regenesis bioremediation and chemical oxidation products. As part of her responsibilities at Regenesis she has reviewed hundreds of potential projects and provided recommendations for remediation. Much of her work over her career has been focused on the development and implementation of bioremediation programs. Over the past several years, she has also been focused on chemical oxidation applications at petroleum and chlorinated hydrocarbon sites. Ms. Dooley has drafted hundreds of project proposals, evaluations and reports related to the feasibility of using bioremediation and chemical oxidation. In addition, prior experience includes the completion of numerous treatability studies designed to evaluate the biodegradation of a wide range of compounds that include pesticides, PAHs and nitroaromatics.
Chlorinated Solvent Remediation using Catalytic In Situ Chemical Oxidation and Accelerated Anaerobic Biodegradation
The individual use of in situ remediation technologies such as microbially mediated enhanced anaerobic biodegradation (reductive dechlorination) and chemical destruction based in situ chemical oxidation (ISCO) for the treatment of chlorinated compounds has been widely documented and accepted with varying degrees of success. Due to the known limitations of each of these approaches (Bio vs. ISCO), the practice of combining or integrating these two technologies is emerging as an effective strategy for optimizing chlorinated contaminant treatment. More specifically the use of a catalytic ISCO reagent applied in sequence with a staged-release, electron donor microemulsion for enhanced anaerobic bioremediation has been shown to be successful at chlorinated sites. Perchloroethene (PCE), trichloroethene (TCE) and dichlorethene (DCE) in high concentrations (mg/L levels and above) can be destroyed effectively with ISCO. However, in most cases, ISCO is only effective at reducing mass, and in the case of a catalytic percarbonate based reagent create highly aerobic conditions for some time following injection. Post-ISCO application, chlorinated solvents can linger on at low levels (< 1 mg/L) in the dissolved-phase. To target residual dissolved-phase concentrations, the use of enhanced anaerobic dechlorination is a compatible and efficient follow-on application to ISCO to reach treatment goals. Timing is key in going from aerobic conditions created by ISCO to an anaerobic biodegradation process . In this case the use of a percarbonate-based catalytic ISCO agent requires some re-acclimation time for the aquifer to buffer the ISCO-induced high DO, ORP, etc. Subsequently the application of a staged-release, microemulsion electron donor can be completed. This abstract will discuss the details of this process as well as performance based case study documentation of its success.
Grant Carey M.Eng., P.Eng.
Grant Carey is an expert environmental engineer and President of Porewater Solutions, and specializes in NAPL characterization and remediation, chemical fate and transport, and mathematical modeling. Grant has worked on hundreds of projects across North America over the past twenty years. Grant has a B.A.Sc. degree from the University of Waterloo, and a Masters degree in Civil Engineering from Carleton University (Ottawa, Ontario). Grant is completing his Ph.D. at the University of Guelph with a focus on quantifying the cost-benefit and limitations associated with partial DNAPL remediation. Grant has developed industry-leading software used for modeling and visualization of reactive transport in groundwater, including BioRedox-MT3DMS and the Remediation ToolKit (SEQUENCE, BioTrends, and BioTracker). Grant has published more than 70 technical papers and courses related to groundwater modeling, chemical fate and transport, and site remediation. Grant is currently participating on several ITRC teams (DNAPL Characterization and Sediments Remediation), and is one of the presenters for the ITRC web seminar on Mass Flux and Mass Discharge. Grant has also previously conducted advanced reactive transport modeling in support of the DoD ESTCP program and the DOE Savannah River National Laboratory.
Use of Mass Discharge to Reduce Remediation Costs at NAPL Sites
Over the past decade there has been a rapid increase in the use of mass flux and mass discharge to refine site conceptual models, and to improve the effectiveness of site remediation and management. For example, there is a growing use of target reductions in source strength (i.e. mass discharge measured in kilograms per year directly downgradient of the source zone) as an interim clean-up goal for DNAPL sites. Mass discharge may be used to prioritize the treatment of multiple sources at large sites to optimize cost versus benefit, and may be used as a metric for evaluation of remedial performance.
This presentation includes a summary of the uses of mass discharge at NAPL sites, measurement techniques, and a review of case studies which clearly illustrate how we can improve the management of contaminated sites through mass discharge monitoring. Factors which limit the achievable reduction in source and plume strength within a reasonable timeframe are discussed. An empirical approach for estimating how much mass discharge reduction is achievable using various in-situ remedial technologies is discussed. A simple NAPL depletion model (NDM) is introduced for predicting the relative remediation timeframe for natural and enhanced dissolution. A sensitivity analysis is presented to illustrate site characteristics which have the greatest influence on remedial timeframes for various types of NAPLs. Case studies quantifying the contribution of back-diffusion to plume strength and remediation timeframe are discussed.
Bruce Tunnicliffe M.A.Sc., P.Eng.
Mr. Tunnicliffe is President of Vertex Environmental Inc., is an Environmental Engineer, and has more than 14 years of experience designing and implementing remediation of chlorinated solvents and petroleum hydrocarbons. Having worked on more than 250 Sites, Mr. Tunnicliffe has extensive experience on in-situ remediation techniques, delivery options and in-situ amendments in both soil and bedrock environments. Mr. Tunnicliffe holds a Master’s degree from the University of Waterloo, has authored many publications, and has presented at numerous conferences. He is a Professional Engineer, and acts as senior reviewer for Vertex’s designs and deliverables.
High Resolution Characterization of Petroleum Hydrocarbons
Use of In-Situ Chemical Oxidation (ISCO) for subsurface remediation of soil and groundwater has increased dramatically over the past 10 years. ISCO techniques are becoming increasingly recognized and recommended by environmental firms. The reaction chemistry is relatively well understood for common contaminants of concern. However, application of ISCO can be problematic, as there can be improper delivery of the remedial amendment into the subsurface resulting in incomplete contact with the contamination.
The purpose of this talk is to explore various methods to ensure better contact between the remedial amendment and the subsurface contamination. Firstly, a better understanding of the contaminant distribution will be examined using two advanced characterization techniques, the membrane interface probe (MIP), and laser induced fluorescence (LIF). Secondly, two amendment delivery methods will be compared and contrasted, specifically injection into wells and injection using temporary points. Examples of when these delivery methods should be used will be presented. Ultimately recommendations will be provided to optimize the design of successful ISCO delivery programs.