����ӰԺ

has won an award from the in the 2024 municipal and civil infrastructure category for design and engineering services on the Golden Ears pump station and sanitary sewage overflow tank project.

The station and sanitary sewage overflow tank, which are owned by Metro Vancouver, are located in Maple Ridge in the Fraser Valley east of Vancouver.

“We are very pleased to have won this award,” says Reno Fiorante, Stantec senior vice-president and project manager.

The new pump station will replace the existing Katzie pump station and help move wastewater from Maple Ridge and nearby Pitt Meadows to the Annacis Island Waste Water Treatment Plant in Delta, and eventually to the upgraded treatment plant in Langley.

When completed, the 22,000 cubic metre storage tank will temporarily store wastewater during wet weather events, providing hydraulic relief to upstream sanitary sewers and reducing sanitary sewer overflow into the Fraser River.

“The Katzie pump station was built in the early 1980s and had to be expanded to support additional growth in Maple Ridge and Pitt Meadows,” says Fiorante. “It was nearing capacity and would have required a major rebuild.”

Metro Vancouver decided to build a new station with a capacity approximately 2.5 times that of the existing station, as well as a sanitary sewage storage tank.

Currently, flows from the Katzie pump station are treated at the Annacis Island plant.

The new Golden Ears pump station will direct flows to the Northwest Langley Wastewater Treatment Plant, which is being upgraded.

Fiorante says the project was challenging.

During the design phase, the project team had to deal with the small site that is located in a quadrant of the 113 B Avenue interchange close to the existing Katzie pump station.

In addition, there were difficult geotechnical conditions, and busy roadways adjacent to the worksite that required careful construction and traffic management.

“To maintain wastewater service during construction, the connections to existing sewers, the Katzie pump station and force mains had to be carefully staged,” says Fiorante.

To contain deep excavations and control groundwater on the site, a sheet pile excavation shoring system was put in place.

A sheet pile shoring system is an excavation retaining system that uses steel sheet piles driven into the ground to retain the soils, which enables the deep underground structures for the sanitary sewage overflow tank to be built.

Staged placement of the sheet piles controlled vibrations and prevented settlement of the existing sewers, the Katzie pump station and the adjacent major roadways.

Combined with de-watering wells, the sheet piles also ensured the excavations were dry, so that construction could proceed in a timely and efficient manner.

A post-disaster facility, the Golden Ears pump station is designed to prevent flotation and remain operational during a major flood or earthquake.

Located in the Fraser River floodplain, the entrance doors are designed to keep out waters during a one-in-500-year flood.

The pump station’s location in the floodplain presented some challenges for the project team.

“The existing site elevation is approximate 2.5 metres above sea level,” says Fiorante.  “In a one-in-500-year Fraser River flood the water level would flood the site. To accommodate operations during a flood, the electrical room and generator are designed above the flood level.”

The tank is designed to resist flotation forces. Doors on the pump station are protected with aluminum stop-logs and designed to withstand hydrostatic forces.

Fiorante says the project has several noteworthy architectural features:  A green roof system, composite cladding, large feature windows on the pump station facade, vertical precast concrete fins suspended from the concrete walls around the pump station and the tank, and public art by a First Nations artist on the fins on the south wall of the tank.

Golden Ears is part of the Northwest Langley Wastewater Treatment Plant program.

Marek Ratajczak, director of the program, says it is required to accommodate population growth in the Fraser Valley sewerage area – Maple Ridge, Pitt Meadows, Surrey and Langley.

“The population served by the plant is expected to grow from 35,000 today to 280,000 by 2041,” says Ratajczak. “Metro did a comprehensive study in 2014. One of the results of the study was the decision to increase the size of the Golden Ears pumping station and redirect the sewage from Maple Ridge and Pitt Meadows to a new regional Northwest Lanley plant from the Annacis Island plant.”

Ratajczak wishes to acknowledge the co-operation on the project of Metro’s member municipalities and the Katzie First Nation.