The estimated cost of one of Hamilton’s most complex construction projects has increased by another $17 million.
The added costs involve trucking nearly 75,000 tonnes of contaminated soil away from the Woodward Wastewater Treatment Plant (WWTP).
A portion of that soil, less than 10,000 tonnes, is considered hazardous and must be trucked to a specialized landfill in Quebec.
The source of the PCB-laden material is the old Brampton Street landfill that closed in the 1970s.
Project manager John Helka told members of a city subcommittee on Monday that the hazardous soil was unearthed during electrical work in the vicinity of the old landfill.
“Those soils that are not deemed hazardous have been typically transported to the Terrapure Environmental landfill site” in Upper Stoney Creek, said Helka.
The discovery has delayed the timeline for “substantial” completion of the more than $300 million expansion of the WWTP, which is considered a major step towards remediation of Hamilton Harbour, which receives the plant’s treated effluent.
Three major contracts make up the bulk of the project, including $87.5 million in upgrades to the main pumping station, $60.9 million for electrical and chlorination improvements and $165 million for tertiary treatment that uses disc-filtration technology.
The federal, provincial and municipal governments have each contributed about one-third of the total project cost.
Helka said the completion date has been pushed back from December 2021 until November 2022.