Thurber Engineering Ltd.

An Environmental Site Assessment (ESA) is the primary tool for evaluation of environmental liabilities associated with a property, and is usually structured in phases. A Phase I ESA involves review of historical records and air photos for the site, a site reconnaissance, and interviews to assess whether or not there is potential for environmental concerns. A Phase II ESA addresses these environmental concerns and incorporates soil and/or groundwater sampling and chemical analyses, to identify types, concentrations and locations of contaminants on-site in relation to meeting or not meeting provincial/federal criteria. A Phase III ESA delineates the extent of horizontal and vertical contamination, based upon additional soil and groundwater sampling and chemical analyses.

Thurber’s expertise includes:

• contaminant identification in soil and groundwater
• hazardous materials identification in the building envelope
• establishing the spatial distribution of contaminants through delineation and modelling
• establishment of remediation options and associated costs
• risk assessment and management

If the occurrence of soil and/or groundwater contamination which exceeds regulatory criteria is established during a phased environmental site assessment, remediation or reclamation are normally required to prevent further environmental impact. Remediation involves containment, removal, or stabilization of contaminants from soil and/or groundwater. Reclamation involves physical reconstruction of soils and terrain on a disturbed site, to achieve equivalent land use capability as to what existed before disturbance.

Thurber establishes remediation/reclamation options and provides design and construction services for:

• excavation and disposal of contaminated soils
• groundwater containment systems (bentonite and cement slurry walls)
• thermal desorption systems
• soil vapor extraction systems
• stabilization and solidification technologies
• development of reclamation plans

Man-made disturbances can affect the ability of the soils to provide the physical, chemical, and biological processes required to sustain natural and crop vegetation. Thurber’s environmental scientists provide a number of services aimed at establishing the ability of disturbed lands to support a particular land use in a sustainable manner.

These services include:

• ecological land classification
• pre and post-disturbance assessments for borrow excavations and industrial sites
• pre and post-harvest silvicultural assessments
• revegetation prescriptions for reclaimed sites
• land capability classification for agriculture and forestry
• level II land irrigability classification

The legacy of the past production and mishandling of solid and liquid wastes is a major public concern in many communities across Canada. Stricter and wider-reaching environmental regulations, as well as broader applications of common law, can impose responsibilities and liabilities on government, business and industries who have inherited contaminated sites which present a risk to human health and the environment. Regardless of whether or not these sites have been remediated, there is often a requirement for independent monitoring and reporting. 

Thurber has expertise in designing, implementing and reporting compliance monitoring programs, in accordance with the local regulatory framework and/or for due diligence purposes.

Services offered include:

• historic land use assessments
• periodic groundwater and soil monitoring and reporting
• data management
• preparation of risk-management plans
• brownfield redevelopment studies
• public consultation

Understanding site geology is an essential first step in any assessment of groundwater supply or contaminant migration. Hydrogeology is the combination of traditional geology with the sophisticated analytical methods required to understand and predict the complex processes involved in groundwater movement and the subsurface fate and mobility of chemical substances.

Services offered by Thurber include:

• field mapping and site specific investigations
• well site selection
• well design
• pumping tests and long term well yield calculation
• groundwater quality assessment
• hydrogeological investigations for ground disposal of wastewater
• monitoring well installation
• surface water and groundwater relationship investigation (GUDI)
• coastal aquifer salt water intrusion investigations
• state-of-the-art groundwater computer model simulations
• contaminant migration and plume monitoring

Planning and design of modern waste disposal facilities requires an extensive knowledge of geotechnical engineering and hydrogeology. As well, construction quality control of all engineered barriers of these facilities requires reliable testing techniques, and long-term monitoring and reporting are normally required to ensure compliance with regulatory guidelines. Thurber Engineering has provided input into all project phases for disposal facilities receiving solids, sludges and liquid wastes, from MSW and oilfield landfills to the tailings dams and waste rock dumps in the mining industry.

Services offered by Thurber include:

• geotechnical and hydrogeological investigations
• laboratory permeability testing
• Air Entry Permeameter (AEP) testing of clay liners
• groundwater containment systems
• foundation and slope stability
• construction supervision and quality control
• long term instrumentation and monitoring
• assessment and testing of recyclable aggregates
• safety of tailings dams and rock dumps

Thurber Engineering Ltd. offers a variety of services to industry and building owners/managers facing hazardous building material risks. We have provided these services to owners/managers of schools, office buildings, apartment complexes, hospitals, shopping malls and industrial properties.

Our services include:

• sampling and inspection of building materials to assess the presence of asbestos, lead paint and polychlorinated biphenyls (PCB) containing electrical fixtures.
• quantification of hazardous building materials.
• asbestos hazard assessment.
• assistance with abatement and management programs for hazardous building materials.
• management and supervision of hazardous building material abatement including assessment of contractor work plans, abatement monitoring and post-abatement confirmatory air sampling.

Occupants of office buildings are frequently unaware of how their health and productivity may be affected by airborne contaminants. Improper design or operation of the ventilation system can result in elevated levels of air contaminants (e.g., carbon monoxide, formaldehyde and other VOCs) which are a health hazard to building occupants. However, determining the cause of the problem is often the most difficult task. Thurber has qualified professionals and modern analytical instrumentation to quantify air quality parameters as well as the expertise to develop cost effective corrective actions.

Our services include:

• occupant response sampling
• sampling of asbestos, lead-based paint, and VOCs
• pollutant source identification and severity assessment
• HVAC systems observation
• development of corrective actions

Risk assessments are being increasingly used to identify appropriate cleanup criteria or the level of remediation efforts required for contaminated sites. Quantitative and qualitative assessments can be applied to make the cleanup of contaminated sites more cost-effective, and create opportunities for redevelopment. Thurber offers a range of risk assessment services to evaluate the current and potential threats to human health and the environment posed by the presence of hazardous substances at contaminated sites and industrial operations.

Our services include:

• hazard identification and analysis
• exposure and toxicity evaluations
• fate and transport modelling
• risk characterization and development of cleanup objectives
• brownfield redevelopment assessments

Conducting an Environmental Impact Assessment  (EIA) at the earliest possible stage of a new development is required to ensure that environmental concerns are explicitly addressed prior to major decisions being taken and commitments made. The EIA process should ensure that the appropriate techniques and experts in the relevant disciplines are employed, and that the interrelationships of environmental, social and economical aspects are brought into play.

We have undertaken multi-disciplinary environmental impact assessments for a wide range of commercial, government and industrial projects. These have included linear corridor developments, mining, forestry, hydroelectric and petrochemical developments, as well as urban and park developments.

Our in-house expertise encompasses:

• environmental impact assessment      
• public consultation and participation in public hearings
• environmental risk assessment and due diligence
• EIA reviews, project management, budgeting, programming

A key focus of mine closure is the reclamation of tailings or mine waste facilities. Successful reclamation of tailings deposits requires achievement of sufficient consolidation to ensure a stable landform, and to prevent ponding on the surface as a result of differential settlement. In the Oil Sands sector, much attention has been paid in recent years to tailings consolidation, treatment of fluid fine tailings, and reclamation technologies.

Thurber is well placed in this field, having served Oil Sands operators and other tailings clients for many years with recognized services in the following areas:

• strategic advice on technology options and decision-making
• roadmap options for tailings reclamation
• assistance with integration of geotechnical, environmental, public, regulatory and legal requirements
• feasibility studies, conceptual design, value engineering
• laboratory testing of consolidation and beaching characteristics of tailings
• planning, supervision and reporting on tailings field trials
• planning and design of tailings facilities to satisfy closure requirements
• review of tailings designs and remediation options
• numerical modelling of tailings deposition
• risk assessment, Failure Modes and Effects Analysis (FMEA)