The McGill University Health Centre (MUHC) announced today that, subject to approvals from the Government of Quebec and the City of Montreal, it is planning to dig up contaminated soil on the Glen site next year and transport it to sites licensed by the Quebec Ministry of the Environment.
"Over the past decade, a number of environmental studies involving drilling, soil samples, observation wells and pumping and hydrocarbon recovery tests have been conducted on the Glen Yard site," explained Denis Isabel, president of EXPERTS ENVIROCONSEIL INC, the firm hired by the MUHC to prepare an environmental assessment of the site. "Given its history and past uses as a transit and maintenance centre for Windsor Station passenger trains, it is not surprising that the main contaminants are petroleum hydrocarbon products and heavy metals. The former consists largely of various forms of diesel oil, while the latter is part of the landfill used to build an artificial plateau on the site."
In preparation for excavation, preliminary characterization of the soil on the site will be carried out in batches. Each rectangular batch will be one metre thick and 100 m3 to 225 m3 in volume. Soil excavation and management will be based on the results of the preliminary characterization of each batch. "The least contaminated soil," added Mr. Isabel, "will be used as cover material at sanitary landfill sites. Soil with a higher concentration of petroleum hydrocarbon products or heavy metals will be treated before being buried at a duly licensed site."
During the excavation stage, the groundwater that collects at the bottom of the holes will be pumped out and taken to one or more temporary storage pools to be decanted of any solid matter. After this solid matter has been removed, the water will be moved to a separator and if necessary, treated before being discharged into the City of Montreal sewer system at the site or the immediate vicinity. Free-phase hydrocarbons will accumulate in the holes and be pumped out with the same equipment used to remove the groundwater, then taken with the water to the storage ponds.
"To clean the site, 950,000 m3 of soil will be dug up but not all of this will need to be removed," noted Jean Dufresne, the MUHC's Chief Planning Officer. "We are currently working with the City of Montreal and the provincial Ministry of the Environment to obtain the necessary permits so that the work can start next spring. In addition, we will be working with the contractor to minimize the impact on traffic."
The cost of the cleanup is estimated to be $33 million, of which $10 million has been contributed by Canadian Pacific, the previous owner of the site. The balance will be paid by the Government of Quebec, as part of its overall support of the project.
The MUHC at the Glen Yard will be a state-of-the-art health centre with a separate research building as well as patient care pavilions, including a children's hospital and a dedicated neurosciences facility. The environmental impact study is available on the MUHC web site: Enviro_Report_Eng.pdf