S4 Pond Embankment Decommissioning

Expertise Hydrotechnical
Market Energy & Resources
Location Western Canada

CLIENT: Conuma Resources Ltd.

OVERVIEW:

Conuma Resources retained PRI to design the decommissioning of the S4 sedimentation pond embankment, which sits beside the Murray River near Tumbler Ridge. PRI prepared a conceptual options report covering hydrotechnical, geotechnical, environmental and mining considerations, with design sketches for every option and preliminary drawings with quantities for the preferred solution.

CHALLENGE:

The embankment sits next to a section of the Murray River that is actively eroding, so leaving it in place was not a long-term answer, and any decommissioning design had to hold up against a moving riverbank. The right solution depended on four sets of constraints at once: river behaviour, embankment and foundation stability, environmental requirements for work beside the river, and the practicalities of an operating mine site.

APPROACH:

Rather than design a single solution, PRI set out the options side by side in one conceptual report:

Hydrotechnical, geotechnical, environmental and mining considerations assessed together for each option, so the tradeoffs were visible in one place.
Design sketches prepared for every option.
Preliminary drawings with quantities developed for the preferred solution.

OUTCOME:

Conuma received a preferred decommissioning solution backed by an integrated assessment of the alternatives, with preliminary drawings and quantities to carry it forward.

Three Valley Gap Remote Avalanche Control System Towers

Expertise Geotechnical
Market Transportation & Infrastructure
Location Western Canada

CLIENT: MoTT C/o: Wyssen Avalanche Control Inc.

OVERVIEW:

Eight permanent Wyssen avalanche towers set on steep, rocky terrain above the Trans-Canada Highway at Three Valley Gap. Each tower stands 8 or 10 m tall and leans out over the avalanche initiation zone. A deployment box on each tower holds 12 explosive charges, which are lowered on a cord one at a time and detonated to trigger avalanches remotely.

Four towers were installed in fall 2016, with the remaining four scheduled for 2017.

CHALLENGE:

MoTT needed to run avalanche control on this stretch of highway at any hour and in any weather, so that closures last only as long as the control work itself. That meant permanent structures placed directly in the initiation zone: steep rock that field crews could reach only by rope, with rock fall hazard to manage during construction and over the life of the towers. Each foundation had to carry a tall tower inclined out over the slope.

APPROACH:

PRI carried the work from investigation through construction:

Site investigations carried out by rope access, providing the ground information for both foundation design and rock fall mitigation.
Recommendations for rock fall hazard mitigation.
Geotechnical and structural design of the tower foundations.
Construction drawings and specifications for the tower foundations and the permanent rock fall protection works.
The construction environmental plan.
Coordinating professional services.
Witnessing of anchor verification testing.
Sampling and testing of the grout and concrete used in foundation construction.

OUTCOME:

The tower system lets MoTT complete avalanche control in all weather conditions, day or night, rather than waiting for conditions that allow conventional control. The result is a more reliable highway and shorter closures. Every foundation was built against verified anchor tests and tested grout and concrete.

372 Martin Street, Penticton

Expertise Civil Engineering
Market Property & Buildings
Location Western Canada

Client: Appelt Properties

Overview
Appelt Properties bought five legal lots on the corner of Martin Street and Wade Avenue in downtown Penticton in 2012. For the next 12 years they were a surface parking lot. Penticton council approved a development permit for a six-storey market rental building in August 2024, and the building opened on September 25, 2026. It holds 75 rental homes: 45 one-bedroom, 25 two-bedroom and five three-bedroom units.

Challenge
The question was whether a downtown parking lot would earn more as homes than as stalls. Fitting six storeys of housing on the site meant giving up most of its parking. A low parking ratio narrows the tenant market and can push parking demand onto surrounding streets.

Approach
Appelt treated the five lots as one site, which gave the building more frontage and a larger floor plate than any single lot could. The building has 26 stalls in a covered, secure garage, or 0.35 per home, plus 40 secure bicycle spaces. It is a bet that downtown tenants will walk, cycle or do without a second car. The site sits in the downtown core, where the City has directed growth. The building needed only a development permit for its form and character.

Outcome
The building opened just over 25 months after council approval. Appelt’s chief financial officer, Justin Bierwirth, called it “the easiest, best process that we’ve gone through.” It adds 75 rental homes in a city whose 2024 Interim Housing Needs Report puts the need at almost 6,300 new homes, or 315 a year. Mayor Julius Bloomfield described the opening as “part of that direction” toward densification.

Frazer Lake Dam Remediation

Location Western Canada

CLIENT: City of Kelowna

PROJECT DESCRIPTION

PRI provided engineering services to the City of Kelowna for the rehabilitation of Frazer Lake Dam, located in the Upper Mission neighbourhood of Kelowna, BC. The preliminary design phase included review of existing documentation, site reconnaissance with a geotechnical subsurface investigation, geotechnical and hydrotechnical analyses, development and evaluation of design alternatives, and a Class C cost estimate. Following preliminary design, the project advanced to detailed design and the completion of tender-ready, issued-for-construction (IFC) drawings and a schedule of quantities.

PRI’s team also completed environmental impact assessments, including several wildlife surveys, and prepared a construction environmental management plan as part of the BC Dam Safety Regulation Plan submission requirements. Key elements of the dam remediation design included:

Removal of the existing earthen embankment, concrete headwall, and outlet works
Temporary cofferdam design
Steel sheet pile cut-off wall
Rock ramp spillway channel
Cast-in-place concrete level control structure
Low-level outlet and gate works

CHALLENGE

Frazer Lake Dam required rehabilitation to meet BC Dam Safety Regulation requirements, but the site’s location within an established residential neighbourhood and its surrounding natural habitat added complexity to the design. The existing earthen embankment, headwall, and outlet works needed to be safely removed and replaced without compromising dam safety during construction, while subsurface conditions had to be well understood to support a durable, code-compliant structure. At the same time, the project needed to account for local wildlife and satisfy the environmental documentation required under provincial dam safety regulations, all while keeping the design on a path to a tender-ready package.

APPROACH

PRI began with a thorough preliminary design phase, reviewing existing records and conducting site reconnaissance, including a geotechnical subsurface investigation, to characterize site conditions. Geotechnical and hydrotechnical analyses informed a set of design alternatives, which were evaluated alongside a Class C cost estimate to guide the City’s decision-making before advancing to detailed design.

The resulting design package paired the removal of the deteriorated earthen embankment, concrete headwall, and outlet works with a temporary cofferdam to allow construction to proceed safely in the dry. A steel sheet pile cut-off wall was incorporated for seepage control, alongside a rock ramp spillway channel, a cast-in-place concrete level control structure, and new low-level outlet and gate works to manage water levels going forward. In parallel, PRI carried out environmental impact assessments and wildlife surveys and developed a construction environmental management plan to satisfy BC Dam Safety Regulation Plan submission requirements, ensuring the design was ready to move directly into tendering.

OUTCOME

PRI delivered a complete engineering solution for the City of Kelowna, from preliminary design through to tender-ready IFC drawings and a schedule of quantities. The rehabilitated dam design meets BC Dam Safety Regulation requirements while incorporating the environmental planning needed to protect the surrounding habitat, giving the City of Kelowna a safe, durable, and regulation-compliant dam for the Upper Mission community.

Vegetation Resource Inventory: Chilcotin Mountains

Location Western Canada

CLIENT: Ministry of Forests, British Columbia

Field Data Collection in Support of Annual Allowable Cut Determination

PROJECT DESCRIPTION

PRI conducted a Vegetation Resource Inventory (VRI) field program in the Chilcotin Mountains of British Columbia to collect ground-sample data used in determining the region’s Annual Allowable Cut (AAC). The 11-day field program gathered stand-level forest attribute data across a remote and ecologically diverse landscape, providing the accurate, defensible information provincial timber supply analysts rely on to set sustainable harvest levels.

CHALLENGE

The Chilcotin Mountains present a demanding field environment. Sample sites are remote and rugged, requiring careful trip planning and self-sufficient crews. The area supports an active grizzly bear population, including sows with cubs, which called for heightened wildlife awareness and safety protocols throughout the program. Streams supporting rainbow trout meant that crews needed to work in and around sensitive riparian and aquatic habitat without disturbing it, while persistent mosquito activity added a further layer of field discomfort and required consistent personal protective measures to keep the crew focused and productive over the full 11 days.

APPROACH

PRI’s field crew followed provincial VRI ground-sampling standards to collect consistent, high-quality stand data across the assigned sample grid within the 11-day window. Daily route and site planning incorporated wildlife safety practices, including bear-aware travel in groups, bear spray and noise discipline, and situational awareness around known grizzly activity. Site access and sampling near watercourses were planned to minimize disturbance to rainbow trout habitat and riparian areas. Standard field protective equipment and insect protection were used throughout to keep the crew safe and comfortable in variable bush conditions, allowing the technical sampling work to proceed without interruption.

OUTCOME

The field program was completed safely and on schedule over the 11 days, with no incidents involving wildlife and no impact to sensitive fish-bearing streams. The resulting VRI ground-sample data was delivered to support Annual Allowable Cut determination for the Chilcotin Mountains area, giving decision-makers reliable, field-verified information for sustainable forest management planning in the region.

Conuma Tailings Storage: Wildlife Baseline Assessment

Expertise Environmental
Market Earth & Environment, Energy & Resources
Location Western Canada

CLIENT: Conuma Resources Ltd.

PROJECT DESCRIPTION:

Conuma Resources Ltd. retained PRI in 2021 to develop an environmental baseline for the Willow Creek Extension (WCE) property, located south of Chetwynd, BC, between Conuma’s existing Willow Creek and Brule Mine properties. Conuma has identified WCE as a potential successor to the Willow Creek Mine.

The baseline assessment covered a maximum disturbance area (MDA) of 971 hectares — representing the geographic extent where direct project effects would occur — surrounded by a 2,492-hectare local assessment area (LAA), within which indirect effects could potentially extend into the broader landscape.

CHALLENGE:

To support a future Environmental Assessment Certificate (EAC) Application, Conuma needed a comprehensive, multi-disciplinary environmental baseline that met the data requirements set out by the BC Environmental Assessment Office, specifically:

The Joint Application Information Requirements for Mines Act and Environmental Management Act Permits (BC MEMPR / MoECCS, 2019)
The Application Information Requirements Guidelines (Province of BC, 2020)

This required coordinating four distinct technical field assessments across a large and ecologically varied landscape, integrating specialized subcontractor expertise while maintaining consistent quality, methodology, and reporting standards suitable for regulatory submission.

APPROACH:

PRI served as both Project Manager and Terrestrial Lead, coordinating a team of specialist subcontracting consultants to deliver four core components of the baseline assessment:

Bioterrain Mapping — supporting Terrestrial Ecosystem Mapping, Terrain Stability Mapping, and Geohazard Mapping (subcontracted to Sitkum Consulting Ltd.)
Terrestrial Ecosystem Mapping (TEM) — including detailed mapping at Ecosystem Survey Intensity Level (ESIL) 4 within the MDA
Rare Plant Assessment (subcontracted to EcoLogic Consultants Ltd.)
Soil and Plant Tissue Sampling for Metals Analysis — with laboratory analysis conducted by ALS Labs, Burnaby, BC (subcontracted to Entia Environmental Consultants)

The mapping work identified Ecosystems at Risk and other valued components, including old forest, wetlands, and riparian ecosystems, ensuring the baseline addressed the full scope of ecological values relevant to a future EAC Application.

OUTCOME:

PRI successfully delivered the Baseline Report to Conuma in March 2022, providing a robust, regulator-ready environmental baseline for the Willow Creek Extension property. The report fulfilled the data requirements outlined in both governing AIR documents, positioning Conuma to advance the WCE property toward a future Environmental Assessment Certificate Application.

LT2 CarbonFree Technology Projects

Expertise Geotechnical
Market Renewable Energy
Location Eastern Canada

CLIENT: Various LT2 Clients

PROJECT DESCRIPTION:
PRI provided on-site support for the CarbonFree Technology LT2 Projects, completing geotechnical investigations and foundation load testing activities for utility-scale solar developments. Drawing on extensive experience across renewable energy projects in Canada, the United States and the Caribbean, PRI applied proven investigation methodologies to deliver the subsurface information needed to reduce foundation-related risk and optimize design.

CHALLENGE:
Utility-scale solar projects carry significant foundation installation risk due to the sheer number of foundations required across variable subsurface conditions — including differing soil types, groundwater, and shallow bedrock. Beyond the solar arrays themselves, major electrical infrastructure such as substations carries substantially greater foundation loads, requiring a deeper and more detailed understanding of ground conditions to avoid costly over-designed foundation which add unnecessary capital expenditures.

APPROACH:
PRI implemented a multi-phase investigation and testing program tailored to the site:

Solar array and substation investigations: Standard array foundation investigations were paired with deeper, targeted boreholes at proposed substation and major equipment locations to characterize subsurface conditions under higher foundation loads.
Helical pile probing and testing: A series of helical probes were distributed across the site to develop a depth-versus-torque profiles, flag areas of installation difficulty, and inform constructability. Representative helical test piles were then installed and subjected to axial and lateral load testing to validate design assumptions and allowing for further optimization. Axial capacity typically governing the overall length of the foundation in this northern climate due to frost uplift; but considerations of lateral capacity must still be considered and cover the overall shaft size which is primarily impacted by wind loading.
Driven pile evaluation: Driven foundations are still the most economical choice for the support of solar racking systems, but may not be feasible due to the increased embedment depth to resist frost uplift. Using the helical probing and geotechnical data, driven pile test locations were selected to compare the performance of W-section and HSS round foundations and ultimately compare to them to the performance of the helical pile option. Installation data (including drive time by depth) were correlated with subsurface findings, and all test piles underwent axial and lateral load testing to confirm capacity and constructability.

OUTCOME:
The combined probing, installation monitoring, and load testing programs allowed PRI to validate foundation performance, confirm constructability across the site, and optimize the final foundation configuration ahead of full-scale production for a combined 477 MWDC solar energy. This proactive, data-driven approach reduced construction risk, improved cost certainty, and gave the project team confidence that the selected foundation systems would meet both structural and constructability requirements — de-risking the project from a geotechnical perspective before installation began at scale.

Kelowna International Airport Culvert Upgrade

Expertise Geotechnical
Market Transportation & Infrastructure
Location Western Canada

CLIENT: Kelowna International Airport (YLW)

PROJECT DESCRIPTION:
The Kelowna International Airport Culvert Upgrade replaced two aging culverts on Mill Creek with a modern, open-bottom box culvert designed to better support natural creek function at the airport site.

CHALLENGE:
The existing culverts were aging and restricted natural creek flow, limiting fish passage and creating flood risk during peak water conditions. Any upgrade needed to address both ecological function and flood resilience without disrupting critical airport operations.

APPROACH:
The team designed and installed an open-bottom box culvert to replace the two existing structures, creating a crossing that better mimics the creek’s natural bed and supports aquatic habitat connectivity, while also improving hydraulic capacity to handle peak flows.

OUTCOME:
The new culvert reconnects approximately 2 km of upstream habitat, improving fish passage and creating healthier conditions for aquatic species. It also enhances flood resilience by reducing bottlenecks during peak flow events, helping protect airport infrastructure, support emergency access, and strengthen long-term operational reliability, demonstrating how targeted infrastructure investments can advance sustainability alongside safety and resilience goals.

925 Laurier Avenue

Expertise Structural Egineering
Market Property & Buildings
Location Western Canada

CLIENT: A Private Developer

PROJECT DESCRIPTION:
925 Laurier Ave — a high-density residential development featuring a concrete podium supporting wood-frame residential units above, designed to maximize footprint and density on a tight urban lot.

CHALLENGE:
The site left little room for error: every square foot had to be maximized to make the project viable, while keeping construction cost-effective. Success depended on solving the “parts no one sees” — the foundations and structural systems — since gaps between consultants on these elements often lead to costly delays and change orders.

APPROACH:
We integrated structural and geotechnical expertise under one roof, treating the building and the ground it sits on as a single problem rather than separate scopes. This eliminated the “seams” between consultants and allowed us to engineer a robust concrete podium to carry the wood-frame units above. We stayed engaged through every phase of construction, from the first foundation pours in winter through final wood-frame assembly, coordinating design from initial concept through completion.

OUTCOME:
The build stayed on schedule, with every detail matching the original coordinated design. The developer received a defensible, buildable project that protects their investment, and future residents gained a reliable, well-engineered home.

Lakeshore Boulevard West Multi-Family Highrise

Expertise Geotechnical
Market Property & Buildings
Location Eastern Canada

CLIENT: Apria Inc.

PROJECT DESCRIPTION:

PRI completed a combined geotechnical and hydrogeological investigation to support the design of a proposed six-storey mixed-use development — 60 residential units over ground-floor retail with two underground parking levels — on a roughly 1,410 m² urban infill site south of Lakeshore Boulevard West. The program characterized the overburden and shale/limestone bedrock, established the groundwater regime and dewatering requirements, and delivered foundation, excavation, shoring and groundwater-control recommendations for redevelopment of the former auto-service property.

CHALLENGE:

The constrained urban infill site abutted existing buildings yet required a two-level basement excavated into shale/limestone bedrock beneath a shallow groundwater table. Interbedded limestone, highly variable rock quality (RQD 0–79%), and groundwater chemistry exceeding City of Toronto sewer-discharge limits added significant excavation, shoring and dewatering complexity.

APPROACH:

PRI delivered an integrated geotechnical, hydrogeological and — with D.M. Wills — environmental program, combining SPT drilling, rock coring and Point Load testing with three months of groundwater monitoring and slug testing. The data were used to model dewatering volumes, define foundation and shoring parameters, and benchmark groundwater quality against municipal discharge criteria.

OUTCOME:

The work confirmed competent bedrock suitable for shallow/raft foundations at 750 kPa (ULS), defined secant-pile shoring and rock-anchor parameters for excavating next to neighbouring buildings, and quantified short- and long-term dewatering rates and permitting requirements (PTTW/EASR). Results were issued in signed Geotechnical and Hydrogeological Investigation reports supporting the City of Toronto SPA/rezoning submission.