Project Summary - Sango Brook Water Intake
Project Name: Water Intake Sango Brook, Natuashish, Labrador
Project Owner: Mushuau Innu Band
Completion Date: November 2010
Contract Value: $7,000,000.00 CAD
Waterworks participated as a subcontractor.
Prior to 2010, the community of Natuashish was reliant upon a number of wells for potable water. Sango Brook was identified as a more reliable source of fresh water and a water distribution system to the brook had been constructed. However, the soil for the final 300 feet of the water intake system was in a liquid state and the system could not be completed using traditional water system construction methodology. The purpose of this project was to complete the installation of the water intake system. The water intake pipe had to be installed 30 feet below the existing grade.
Natuashish is located on the northern coast of Labrador, 185 miles north of Happy Valley-Goose Bay. The community is accessible only by air, and water during the summer months. Natuashish is a new community, which was developed in 2002. Previously, the Mushuau Innu Band were located in Davis Inlet, an island community which had limited access to resources and traditional hunting grounds.
Firm’s Responsibility on the Project:
The engineering firm managing the project could not find any contractors willing to take on the work. This included all of the pre-qualified bidders. Accordingly, the contract value was negotiated by Waterworks and Pennecon Limited (Pennecon was one of the pre-qualified bidders) on the condition that Pennecon would be the general contractor and 100% of the work would be subcontracted to Waterworks.
Waterworks utilized their own equipment to complete this work. Most of the equipment and material required for the project, including an 80 ton crane, piping, SSP, excavators, a 35 ton articulated rock truck, and other associated heavy machinery, were loaded on barges in Dartmouth NS and towed to Natuashish; a distance of approximately 2,000 km. Once unloaded in the community of Natuashish, the equipment was then moved seven miles over a gravel road to the work site. Waterworks stabilized the soil in the work site area to facilitate equipment operation.
Waterworks developed a method to work in the liquefied soil. They engaged a team of structural and geotechnical engineers to design a 100 foot long, sheet pile cell with a full whaler bracing system. The sheet piles were installed using the crane and a vibration system. Waterworks then excavated the material inside the cell until they had reached the appropriate soil grade level. An internally heat-traced high density polyethylene pipe, that ran through the sheet piles at each end of the cell, was then installed. The cell was backfilled and the sheet piles (with the exception of the piles with the piping) were withdrawn and used for the next cell. This process was repeated a total of three times until the required 300 feet of piping had been completed. As the second and third cells were completed, the polyethylene pipe was connected to the pipe laid in the previous cell. Once all three cells had been completed, the intake pipe was connected to the existing water distribution system.
There was some concern that the material that was withdrawn by Waterworks would leach into the water table and contaminate the existing water source. Accordingly, Waterworks created lined settlement ponds to dewater the material removed from the cells. Once the sediment from the material had settled, the ponds were drained and the resulting sediment was disposed of.
Due to the amount of work that had to be completed and the relatively short construction season at Natuashish, the work had to be completed over two summers. The project was started in the Spring of 2009 and completed in November 2010.
Relevance of the Project:
- The effort to design and build the SSP cells in an example of Waterworks’ ability to work with a team of designers to develop the best-value solution for a challenging project.
- This project highlights Waterworks' years of experience in the heavy civil construction industry. This experience has been gained from numerous unique and challenging projects like the Sango Brook Water Intake.
- Natuashish has an inhospitable, subarctic climate with a cold spring and fall and a cool summer. Winters are frigid and characterized by deep snow. In order to mitigate hazards a safety plan was developed for the Natuashish site and hazard assessments were completed.
- The project required Waterworks to mobilize a significant amount of material and equipment and transport it by barge over 2,000 km. Furthermore, the work was done in a very remote part of Canada with sea transportation support available for only part of the construction season. Although air transportation support was available for the entire season, this mode of transport is extremely expensive. Therefore, this project required meticulous logistics planning and coordination with the project engineers, managers, and associates of all invested parties to complete the work as efficiently as possible.