The 99th Avenue Sanitary Trunk Sewer has been a critical component of the City of Edmonton‘s wastewater collection system since the 1970s. The 1.1 kilometre long sanitary trunk sewer is located approximately 30 metres below ground and serves a crucial role in conveying combined sanitary flows from the city’s west end through residential and commercial areas in the West Jasper Place neighbourhood. Over the decades, exposure to hydrogen sulfide gas and natural wear led to significant degradation of the sewer.

EPCOR Utilities manages the City of Edmonton’s wastewater and water systems. Recognizing the urgency of addressing the deteriorating condition of the sewer to prevent potential service disruptions, EPCOR retained Shanghai Construction Group, with Associated on their team, to construct Phase 1 of the project.

The primary objective of the project was to rehabilitate the existing trunk sewer to restore its structural integrity and enhance its capacity to handle future wastewater flows. This included the construction of a new 1.6 kilometre bypass sewer using advanced microtunneling technology, to divert flows during the rehabilitation process, and provide additional capacity for future development.

With the sewer’s location in a densely populated urban area, it was essential to minimize disruptions to the community and ensure the safety of residents and workers. Significant technical challenges included complex geological conditions, deep tunnel alignments, and proximity to existing infrastructure and environmentally sensitive areas. EPCOR and project partners devoted considerable time and resources to developing a comprehensive plan that would address the project’s technical, logistical, and community-related challenges. To minimize community impact, the project was delivered in two stages spanning three years and incorporated proactive community engagement.

One of the most significant challenges of the project was selecting an appropriate alignment for the bypass sewer. We conducted extensive geotechnical investigations to understand the soil conditions along the proposed alignments. This involved drilling numerous boreholes and conducting soil tests to assess the composition and stability of the ground at various depths.

This assessment showed a number of challenging conditions for the tunnelling to traverse. This includes rafted bedrock, sand seams, with boulder fields all within the dense clay till.

Employing advanced construction techniques were critical to addressing technical challenges and the success of the project. One key decision was selecting microtunneling as the preferred construction methodology. Microtunneling allowed for the installation of underground pipelines with minimal surface disruption. This was particularly important for this project, given the depth of the tunnel and the proximity to existing infrastructure. Significant secant structures were constructed in order to reach the depth needed for the installations.

A significant portion of the project was located within the North Saskatchewan River Valley, one of Edmonton’s most environmentally sensitive areas. The river valley is not only a vital ecological corridor, but also a cherished natural asset, providing habitat for wildlife, as well as recreational spaces. The project team implemented rigorous environmental protection measures. Construction activities were carefully planned and executed to minimize disruption to the natural environment, particularly within the river valley. Special attention was given to preserving the integrity of the existing landscape, and the overall ecological balance of the area.

North American Society for Trenchless Technology’s 2024 Project of the Year Award Winner

The Sanitary Trunk Bypass not only enhances the resilience of Edmonton’s wastewater system, but also sets a new standard for considerations for long-term resiliency of new infrastructure.

Our team supported our client, Shanghai Construction Group, with the complex design components of the works left which included the hand tunnel connections, manhole structures, and inflow bypass and abandonment plans. With the support of our survey team, a 974 metre microtunnel drive was successfully completed with the boring machine reaching its target within 150 millimetres at the end, which is an amazing achievement.

Associated’s team was led by Jason Lueke and included Chris Lamont, Sam Saunders, Ryan Krausher, Dusanka Stevanovic, Caitlin Lou, and Greg Walker.

Stay tuned for our work as the Design Build Engineering Lead working with Shanghai Construction for the rehabilitation work of the existing tunnel that is currently under construction.

The post Award-winning infrastructure project provides reliable, long-term wastewater collection service for Edmontonians first appeared on Associated Engineering.

The Canadian Underground Infrastructure Innovation Centre (CUIIC) announces the award of a Natural Science and Engineering Research Council (NSERC) Alliance Grant for the groundbreaking project titled “Greenhouse Gas Emission Reduction in Design, Construction, Repair, and Maintenance of Underground Infrastructure.”

This initiative, led by Dr. Alireza Bayat, Professor of Civil and Environmental Engineering and Director of CUIIC, brings together three Canadian universities to develop innovative strategies and technologies aimed at mitigating greenhouse gas emissions across various phases of underground infrastructure projects. The co-applicants include Dr. E. Davies, Dr. L. Hashemian, and Dr. S. J. Birchall (University of Alberta); Dr. R. Dziedzic (Concordia University); and Dr. I. L. Stefanovic (University of Toronto).

NSERC and 21 industry partners are funding cash and in-kind contributions totalling three million dollars over five years. The research will provide training opportunities for ten graduate and undergraduate students, allowing them to gain hands-on experience and interact with industry professionals in the field of underground infrastructure.

The Industry Partners include: Associated Engineering, EPCOR Water Services Inc., Metro Vancouver, Insituform Technologies, Region of Peel, AECOM, UDI Edmonton, Alberta Roadbuilders & Heavy Construction Association, Mott MacDonald Canada Ltd, Stantec Consulting Ltd., ATCO Gas and Pipelines Ltd, Dura-Line, eTrenchless Group, Lafarge Canada Inc., North American Society for Trenchless Technologies-NW Chapter, ParklandGEO, Precon, PW Trenchless Construction Inc., Westlake Pipe & Fittings, Benjamin Media Inc., Uni-Bell PVC Pipe Association.

Jason Lueke, P.Eng., Ph.D., National Discipline Leader, Trenchless Technologies, says, “Associated Engineering is excited to collaborate with CUIIC, NSERC, and our industry partners on this important program to develop strategies to reduce GHG emissions on underground infrastructure projects.”

CUIIC, housed at the University of Alberta, continues to be at the forefront of research and innovation in underground infrastructure leading collaborative efforts between academia and industry to address critical infrastructure challenges.

Dr. Bayat expressed his excitement about the project, stating, “This initiative will advance sustainable practices in the design, construction, repair, and maintenance of underground infrastructure, significantly reducing greenhouse gas emissions and contributing to environmental conservation efforts.”

The post CUIIC awarded major NSERC Alliance Grant for underground infrastructure research first appeared on Associated Engineering.

Associated Engineering is very pleased to be a supporting sponsor of No-Dig North taking place next week in Edmonton! Supported by the British Columbia, The Great Lakes, St. Lawrence & Atlantic, and Northwest Chapters of the North American Society for Trenchless Technology (NASTT), this year’s event includes a full day of Good Practice Course sessions and a two-day technical program. Key members of our infrastructure practice from Alberta and Ontario will be presenting on all three days and we welcome attendees to hear from them in the following sessions. 

October 23rd

Pre-event Good Practices Course – Horizontal Directional Drilling (HDD)
Presenter: Jason Lueke

The HDD Good Practices Guidelines course provides an in-depth overview of Horizontal Directional Drilling (HDD) and covers six topics: (1) operation and application; (2) equipment and materials; (3) planning, including surface and geological investigations, utility surveys, bore planning, and regulations and permitting; (4) job site safety; (5) risk reduction, troubleshooting and mitigation; and (6) design.

October 24th

10:05 AM – 10:30 AM | Salon 9
Dunlop St Trunk Sanitary Sewer Relocation – MTBM Highway & Creek Crossing with Limited Cover
Presenter: Thomas Siuda

This paper will discuss the tunnel design by Associated Engineering (Ont.) for the Dunlop Street Trunk Sanitary Sewer Relocation project in the City of Barrie. The project features the design and construction of a 900mm inside diameter (1200mm outside diameter), 235m microtunnel drive crossing Highway 400 and Dyments Creek. Due to design constraints set by the existing sanitary system and required hydraulic performance, there was limited cover for the tunnel underneath both the major six-lane highway and the environmentally regulated creek. As such, the tunnel design was primarily constrained by the vertical alignment and minimal cover. The cover led to design challenges when considering size of tunnel boring machine, operating face pressures, potential for frac out and environmental conditions. The minimal cover under the creek was determined to lead to a frac out and required a design for temporary mitigative measures to place fill above the tunnel crossing and to divert the existing creek through a temporary culvert. The geotechnical conditions allowed for a feasible tunnel path under the highway and the sensitivity of the variable conditions within the design will be demonstrated. This paper will detail the design considerations and calculations used to determine the feasibility of tunneling with the available cover along the alignment and explore the risks.  

2:35 PM – 3:00 PM | Salon 9
99 Avenue Sanitary Trunk Bypass: Stage 1 – Microtunnel Installation
Presenter: Christopher Lamont

The 99 Avenue Sanitary Trunk Bypass is a two-stage project to ultimately rehabilitate an approximately 1.1 km of cast-in-place concrete arch shape sanitary trunk sewer in Edmonton, Alberta that has been in service for over 70 years. The existing trunk is a crucial link in Edmonton’s wastewater collection system receiving flows from Edmonton’s west end. Phase 1 of the project includes the construction of a ~1.6 km long, 1,800 mm inside diameter bypass sewer, to divert flows for the Phase 2 trunk rehabilitation, and ultimately increase conveyance capacity. The existing tunnel is approximately 30 m below ground, and as such microtunnelling was specified as the required installation methodology for the bypass. The microtunnelling scope was awarded to Shanghai Construction Group (Canada) Corporation. The construction methodology included three drives: ~975 m long, which included a sensitive crossing of the MacKinnon Ravine; ~390 m long; and ~250 m long. Construction started in August 2020 and is anticipated to be complete by mid-2023; the final microtunnel drive was completed in November 2022. Project challenges included difficult ground conditions (abrupt changes in soil strata such as glacial clay till with frequent cobbles and boulders, sand seams, and occasional slabs of clay shale bedrock), complex deep tunnelled connections, tunneling distance, proximity risk to the existing degraded tunnel, and management of the social impacts of the project due to the duration of construction.

2:35 PM – 3:00 PM | Salon 8
Newton Force Main Replacement from Concept to Construction
Presenter: Jason Lueke

The Newton Force Main crosses the Red River in the City of Winnipeg between Fraser’s Grove Park and Newton Avenue / Scotia Street, conveying combined sewage flows from the Linden and Hawthorne Combined Sewer Districts east of the River to the Main Street Interceptor trunk west of the river. The existing crossing includes dual 350 mm diameter pipes constructed in 1960 (steel) and 1978 (HDPE), which were inspected in 2014 and 2018, respectively. Excessive deformation and leaks were identified along the HDPE force main triggering the need for a replacement crossing. A conceptual study was conducted in 2021 to develop routing concepts considering horizontal directional drilling and microtunnelling installation methods and a drilled crossing between Fraser’s Grove Park and Kildonan park was evaluated to be the preferred replacement concept. Detailed design was completed in 2022 and the project was tendered and awarded to Accurate HD Ltd. The replacement crossing consisted of approximately 466 m of 500 mm HDPE DR7 product at a target crossing depth of approximately 32 m below the riverbed within medium strength limestone bedrock (Selkirk member of the Red River Formation). The crossing included a horizontal curve beneath the river and required entry and exit conductor casing through the alluvial overburden soils. A drill intersect method was utilized by Accurate HD Ltd. to install the conductor casings and complete the pilot bore; pullback was successfully completed in March 2023 with a maximum reported pull force of 52,000 lbs.

4:05 PM – 4:30 PM | Salon 9
Northwest Inner City Microtunnel for the Upper Plateau Sewer Separation Project
Presenter: Nadeer Lalji, Jason Lueke 

The Northwest Inner City (NWIC) Upper Plateau Sewer Separation Project is a multi-year project designed to alleviate flooding in the Sunnyside inner-city community in Calgary, Alberta. The project includes the implementation of a large diameter storm trunk syphon to intercept stormwater from the upslope communities, bypassing Sunnyside and discharging directly to the Bow River. Trenchless construction was deemed necessary to minimize disturbance to the community and traverse the change in topography from McHugh Bluff at the edge of the upper plateau to the lower elevation Sunnyside community and ultimately the Bow River. The project was designed as a single ~755 m long, 3,400 mm inside diameter, tunnel drive between a launch shaft near the apparent intersection of 10 Street and 8 Avenue NW and a reception shaft near the intersection of 7 Street and Memorial Drive NW, adjacent to the Bow River. The tunnel alignment consisted of two distinct sections: a deep section beneath McHugh Bluff through Paskapoo Formation bedrock that included a crossing of the Calgary CTrain metro line and a horizontal curve; and a relatively shallow section (less than three tunnel diameters of cover) along 7 Street within Sunnyside initially through bedrock, but ultimately transitioning into the alluvial channel deposits. Construction started in November 2021 and is anticipated to be complete by mid-2023; installation of the storm trunk syphon was completed by microtunnelling at the end of 2022.

2:35 PM – 3:00 PM | Salon 8
Newton Force Main Replacement from Concept to Construction
Presenter: Jason Lueke

The Newton Force Main crosses the Red River in the City of Winnipeg between Fraser’s Grove Park and Newton Avenue / Scotia Street, conveying combined sewage flows from the Linden and Hawthorne Combined Sewer Districts east of the River to the Main Street Interceptor trunk west of the river. The existing crossing includes dual 350 mm diameter pipes constructed in 1960 (steel) and 1978 (HDPE), which were inspected in 2014 and 2018, respectively. Excessive deformation and leaks were identified along the HDPE force main triggering the need for a replacement crossing. A conceptual study was conducted in 2021 to develop routing concepts considering horizontal directional drilling and microtunnelling installation methods and a drilled crossing between Fraser’s Grove Park and Kildonan park was evaluated to be the preferred replacement concept. Detailed design was completed in 2022 and the project was tendered and awarded to Accurate HD Ltd. The replacement crossing consisted of approximately 466 m of 500 mm HDPE DR7 product at a target crossing depth of approximately 32 m below the riverbed within medium strength limestone bedrock (Selkirk member of the Red River Formation). The crossing included a horizontal curve beneath the river and required entry and exit conductor casing through the alluvial overburden soils. A drill intersect method was utilized by Accurate HD Ltd. to install the conductor casings and complete the pilot bore; pullback was successfully completed in March 2023 with a maximum reported pull force of 52,000 lbs.

4:05 PM – 4:30 PM | Salon 9
Northwest Inner City Microtunnel for the Upper Plateau Sewer Separation Project
Presenter: Nadeer Lalji, Jason Lueke 

The Northwest Inner City (NWIC) Upper Plateau Sewer Separation Project is a multi-year project designed to alleviate flooding in the Sunnyside inner-city community in Calgary, Alberta. The project includes the implementation of a large diameter storm trunk syphon to intercept stormwater from the upslope communities, bypassing Sunnyside and discharging directly to the Bow River. Trenchless construction was deemed necessary to minimize disturbance to the community and traverse the change in topography from McHugh Bluff at the edge of the upper plateau to the lower elevation Sunnyside community and ultimately the Bow River. The project was designed as a single ~755 m long, 3,400 mm inside diameter, tunnel drive between a launch shaft near the apparent intersection of 10 Street and 8 Avenue NW and a reception shaft near the intersection of 7 Street and Memorial Drive NW, adjacent to the Bow River. The tunnel alignment consisted of two distinct sections: a deep section beneath McHugh Bluff through Paskapoo Formation bedrock that included a crossing of the Calgary CTrain metro line and a horizontal curve; and a relatively shallow section (less than three tunnel diameters of cover) along 7 Street within Sunnyside initially through bedrock, but ultimately transitioning into the alluvial channel deposits. Construction started in November 2021 and is anticipated to be complete by mid-2023; installation of the storm trunk syphon was completed by microtunnelling at the end of 2022.

October 25th

4:05 PM – 4:30 PM | Salon 8
Opportunities and Challenges when Delivering Construction Administration for a Project Designed by Another Firm
Presenter: Liam Sykes

This paper discusses the importance of having good collaboration between the entire project team, as well as a strong technical team for Contract Administration and Inspection when the Consultant administering the construction did not participate in the design, using the Langstaff Gateway Sanitary Sewer project as an example. The project for York Region (Region) involved 2.1km of 900mm and 1200mm sanitary sewer, installed almost entirely by microtunneling. Associated Engineering (Associated) was awarded the Construction Administration portion of the project, which was designed by a different consultant team (Design Consultant). This paper explores several opportunities and challenges on the project that were unique to or amplified by not being responsible for the design, and how they were overcome. Both technical and non-technical challenges and opportunities are discussed, including review of design change proposals made by the Contractor, unforeseen construction issues such as utility conflicts requiring design changes, interpretation of the contract and reports to respond to claims, and coordination with other stakeholders and the Design Consultant. These examples demonstrate the importance of having a team with a strong tunneling background to quickly respond to construction issues and provides a framework for dealing with design changes and construction administration collaboratively on similar projects. The paper concludes with a discussion on lessons learned and some of the benefits and drawbacks of using this approach.

The post Associated at No-Dig North 2023 first appeared on Associated Engineering.