Northwest Langley Wastewater Treatment Plant

Located on the bank of the Fraser River, the Northwest Langley Wastewater Treatment Plant serves a population of 27,000 residents within the Walnut Grove area of Langley, B.C. With goals of improving the final effluent quality and providing capacity for future population growth, Maple Reinders upgraded the facility with three new 28m diameter secondary clarifiers and two activated sludge tanks.

The final treated discharge of this treatment plant enters directly into the Fraser River, one of the largest and most protected fish bearing rivers in North America. Prior to commencing pile installation and raft slab construction, Maple Reinders developed a comprehensive groundwater management plan that had to account for fluctuating river levels based on tidal impacts and the annual Fraser River Freshet, as well as sediment removal to acceptable levels prior to discharge into Fraser River.

Maple Reinders’ scope on this project also included the installation of 260 driven piles, 500mm diameter by 30m deep driven steel piles beneath a large raft slab, on which the new structures would be founded. The design suggested the raft slab be divided into 31 concrete pours but after review with the structural engineer the final pour plan was reduced to 13 pours, greatly improving on construction efficiency and schedule.

Extensive coordination and planning was required to ensure that the continued operation of the existing treatment plant was maintained at all times.