Foundation construction in the remote terrain and subfreezing temperatures of Northern Ontario is no easy feat. It takes advance planning, creative problem-solving and careful execution. But, when it results in connecting remote communities to the grid for the first time, working through the challenges and obstacles all becomes worth it.
The Wataynikaneyap Power Transmission project
The Wataynikaneyap (Watay) Power Transmission project involved an estimated 1,800 kilometres (1,118 miles) of new transmission line, ranging in voltage from 25 to 230 kilovolts, and 22 new substations in Northern Ontario. The project was intended to develop and reinforce electricity supply by connecting 17 remote First Nations communities to the provincial power grid.
These communities had previously run exclusively on diesel generation, which can be expensive and unreliable. A recent Independent Electricity System Operator (IESO) study indicated that diesel was Ontario’s most expensive power resource, costing these communities approximately $90 million annually. Additionally, many of the diesel generation units were either at, or close to reaching, maximum capacity. The inefficiency of diesel use was not only impacting the immediate economic landscape of the affected communities, but was also impeding long-term sustainability and financial stability. Connecting to the grid reverses these trends, substantially increasing power reliability and empowering these growing communities.
Foundation challenges
Before the project could be successfully completed, the project team had to overcome substantial foundation hurdles. The scope entailed the installation of 1,150 micropiles and 260 grouted anchors for 185 guyed and self-supporting lattice tower structures across difficult terrain and in complex geology, resulting in significant access and installation challenges. Located in remote areas of the province, traditional road access was sparse and ground conditions varied widely. Harsh winters created ice roads during the colder months, which were traversable with the right equipment, but turned boggy during spring break and became impassible.
Compounding access challenges and subsurface conditions across the alignments were diverse and mostly unconfirmed before construction began. During design phases, a combination of grillage, helical piles, micropiles and rock anchors were contemplated to support project structures. Grillage was deemed unfeasible at many locations early on in construction, as it relies on a relatively shallow, dense bearing stratum that was not encountered. It became clear that the project team would need to revise foundation solutions at several sites to accommodate both the access and unknown subsurface challenges.
Foundation selection and construction
Engineering, procurement and construction contractor Valard Construction selected micropiles and grouted anchors for sites with significant access challenges. The necessary materials and equipment can be componentized and lightweight, allowing for mobilization via track vehicle when ice roads allowed, and helicopter when they did not. Micropiles can also accommodate a broad range of subsurface conditions and can be efficiently adapted during construction. It was determined that micropiles would provide a much-needed solution. They would accommodate helicopter construction at the project’s remote site locations and achieve the required capacities in the diverse rock and soil found in Northern Ontario’s wet, boggy and intensely cold environments.
Valard engaged foundation contractor Crux Subsurface (Crux) to install micropiles and anchors. Crux utilized patented micropile spin drills, custom fabricated in-house to accommodate project requirements. The drills were componentized and lightweight, enabling them to be broken down and transported by helicopter or track vehicle depending on conditions. Drills were track-mounted during the winter months to traverse the ice roads and reconfigured for helicopter access during the warmer months when the boggy terrain became impassable.
Most of the micropiles installed on the project relied on helicopter support, requiring the project team to maximize helicopter usage during the summer months. Helicopter construction featured custom levelling platforms to provide a stable surface for equipment and materials in the rugged terrain. The platforms also provided a template for the rotating micropile drill, allowing all piles in each array to be installed without relocating the drill or requiring additional helicopter support.
Site-specific subsurface conditions were verified during the drilling of the first micropile at each structure location, which effectively determined the total number and depth of piles required, as well as the grouting specifics, for that foundation. This patent-protected process allowed for designs to be quickly and efficiently tailored to the geotechnical conditions encountered at each site without requiring redesign or impacting construction schedules. Uplift testing was completed on one pile per foundation to confirm capacities, and piles were secured with a prefabricated steel micropile cap. High-strength grout enabled structure assembly to begin within four to five days of installation, supporting the critical path of construction sequencing.
Foundations ranged from three to six piles and were installed to depths of up to 90 feet. In total, Crux installed 1,150 micropiles and 260 anchors to support 185 guyed and self-supporting structures.
Subsurface characterization, micropile installation and testing activities were supported by a qualified team of on-site engineers and geologists. Foundations ranged from three to six piles and were installed to depths of up to 90 feet. In total, Crux installed 1,150 micropiles and 260 anchors to support 185 guyed and self-supporting structures.
Compounding challenges
In addition to anticipated foundation obstacles, extreme and unpredictable weather conditions compounded challenges on the project. Temperatures reached -50°F (-45.6°C) on multiple occasions, rendering the need to maintain strict temperature control during construction extremely difficult. Crews utilized warming blankets as appropriate and ran diesel engines continuously for 24 hours a day to avoid any stop-start issues. In addition, the project team operated with a heightened awareness of cold-related hazards, such as slippery surfaces and frostbite.
Contrasting the extreme cold, the project also experienced one of the worst wildfire events in area history during the summer of 2021. In late July 2021, more than 107 active wildfires were burning in the region, with 32 considered not under control. The province was forced to impose emergency order restrictions on various industries – including mining, rail, transportation and construction – to reduce the likelihood of additional fires igniting before existing fires could be contained. The Watay transmission project, specifically, experienced a six-month delay. This was a major challenge mid-project and required project stakeholders to work diligently to make up time wherever possible once construction resumed.
Working internationally during a global pandemic presented numerous unique challenges no one could have predicted. Crews worked diligently with medical staff and governing authorities to ensure all COVID-19 protocols were followed. Testing was completed upon each border crossing, and crew members were assigned specific man camp dorms and vehicles. Meals were delivered to rooms instead of eaten communally, and other distancing measures were implemented. Operations remained consistently flexible to accommodate slow and unreliable cross-border shipping and travel.
Overall, the project team worked diligently to minimize COVID-related delays and complete work successfully despite the extreme cold and fire challenges. The team’s ability to handle these fluctuating conditions was a major benefit to both constructability and a schedule that had already seen delays.
Project’s completion
All foundations were successfully installed, and the construction team met its substantial completion date. Seven First Nations communities were officially tied into the provincial power grid and energized in 2023, with nine additional communities planned to be energized throughout 2024.
However, the Watay Power transmission project isn’t just about wires, substations and overcoming foundation challenges. It’s about empowering communities, bridging gaps and lighting up lives.
“Wataynikaneyap” in the Oji-Cree language means “the line that brings the light.” Connecting these communities to the grid provides their populations with clean, reliable electricity to power homes, schools, water treatment plants and critical infrastructure. The profound impacts this will have on the connected communities are already beginning to surface and will continue for years to come.