Environmental Remediation Award of Excellence
United Boulevard Recycling and Waste Centre Morrison Hershfield
Supporting sustainability More than 40,000 tonnes of incinerator bottom ash that would otherwise go to waste was used as structural fill. In fact, no material excavated on the site ever left; it was all reused. A concrete mat foundation supports the transfer building, to eliminate potential complications related to piles penetrating the base of the landfill. The site is sealed to prevent infiltration and leaching of contaminated water. An impermeable geomembrane barrier, asphalt and concrete meet BC Landfill Closure Criteria. Surface rainwater is redirected to the stormwater collection system, while landfill gas is directed from below to its own collection system, which burns methane and other harmful emissions, reducing them by 99%. Building on landfill Constructing on a former landfill involved structural and environmental challenges, such as mitigation of landfill gas, total and differential settlement due to municipal waste compression, vector control and cut/fill balance of grading. Municipal solid waste (MSW) and compressible soil restricted 42
CANADIAN CONSULTING ENGINEER
the site’s layout, grading and structural design. Modelling the geological profile provided parameters for settlement and seismic design. The buildings were designed to accommodate differential settlement. The prefabricated metal building has flexible utility connections and rests on a slab-on-grade concrete foundation to resist twisting and cracking. Site grades avoid significant excavation depths into the MSW and grading fill heights that would trigger significant settlement. Landfill gas is managed by an active system, a liner system including utility ‘boots’ for slab penetrations and a liquid membrane beneath the building slabs. Raft foundations sitting well above the MSW allow for easier application of membranes to prevent landfill gas from accessing the building. Construction began in 2018. The centre opened to the public in March 2022. United Boulevard Recycling and Waste Facility, Coquitlam, B.C. Award-winning firm (prime consultant): Morrison Hershfield, Burnaby, B.C. (Lillian Siu, P.Eng.; Don McCallum, P.Eng.; Todd Baker; Jeremy Hapchina, P.Eng.; Rex Dimaano; Matthew Yim; Nathalie Marble; Dwight Dancy; Eva Robertsson, EIT; Jeff Kemps). Owner: Metro Vancouver. Other key players: HDR (civil, architecture), Thurber Engineering (geotechnical), Watson & Barnard (surveying), Stuart Olson (general contractor), Mettler Toledo (scales), SSI Shredding Systems (compactor).
September/October 2022
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etro Vancouver’s United Boulevard Recycling and Waste Centre sits on 6.2 ha of brownfield on the former Coquitlam Landfill. Morrison Hershfield’s (MH’s) project team facilitated development on a closed site. The steel superstructure is nearly the size of four hockey rinks, with a clear span of 71.4 x 98.5 m providing flexibility for operations. The transfer building has a 5,800-m2 flat tipping floor, three material chutes, a below-grade compactor and a maintenance garage. The site also hosts an administration building, two scale houses, six scales and a recycling attendant booth. The project includes a landfill closure system, landfill gas collection and street upgrades. By replacing an old facility that was situated on leased land, the new centre saves Metro Vancouver the cost of rent. As a one-stop drop-off facility, it has a processing capacity of about 600 tonnes per day and is open 363 days a year. And the site is expandable.
