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Matrec undertook works for the permanent closure of the Pierrefonds landfill site (former Meloche quarry).


Winter break for closure works

Despite the delays caused by COVID 19 and weather conditions, all biogas wells have been installed and are now connected to the new flare. In addition, the entire landfill area is now covered with an impermeable membrane to seal the site and keep the biogas under the membrane. Thanks to the new high-capacity capture system recently installed, the biogas are now collected and directed to the new flare for destruction.

Thus, the work carried out by Matrec over the past two years – valued at more than $ 10M – now means that the biogas generated by landfilled materials (which previously were responsible for odors in the area) cannot escape the site anymore and are now destroyed by the new flare.

A peripheral ditch and a retention basin were also built in order to collect and manage rainwater on the site.

Since December 4, 2020, work has been suspended for the winter break; they will resume during the spring of 2021.


Remaining work to be completed in 2021

The only work that will have to be carried out in 2021 (after the winter break) consists of placing the last layers of cover material (backfill and topsoil) in a specific section of the site as well as certain landscaping work. Once these last works are completed, the site will be closed permanently.


Tight controls after site closure

Regulations require landfill owners to closely monitor facilities for 30 years after the site is permanently closed. Matrec will therefore have to submit regular control reports to the MELCC. To this end, the company has created a multi-million dollar fund to monitor the site in the future.

The site is now fully sealed following the installation of the impermeable membrane and all biogas wells are operational. All the biogas is now captured and directed to the new flare for destruction.
Photos taken at the end of October 2020>
In 2021, only the installation of the last layers of cover materials will remain on a specific section of the site. Minor landscaping work and final seeding of the site will be carried out during the summer.

New stormwater retention catch basin

An important milestone has been reached in our site closure works. A catch basin was built in the northwest section to collect runoff water once site closure is completed. The construction work was completed as scheduled and the basin is operational since June 17.

The catch basin is equipped with an impermeable membrane and is filled with a layer of stone to collect runoff water from the perimeter ditch newly constructed around the site. In addition, four biogas wells have been installed near the catch basin and are already connected to the new flare.



Phase 2 of the work to close the Pierrefonds landfill (former Meloche quarry) have resumed last April.

Works will notably include the drilling and installation of more than 20 new vertical biogas wells in the eastern section of the site and these will be connected to the new flare that went into service in January 2020. These new biogas wells are in addition to the 15 other wells installed and in service since 2019 in the West section of the site. Once the wells are drilled and installed in the eastern section, Matrec will install the geomembrane and the various layers of cover materials. In addition, the installation of cover materials will be finalized on the West section on which the geomembrane was installed in 2019. A perimeter ditch will also be developed to redirect rainwater to a retention basin.

Pierre Fonds site map

Once completed, this work, worth more than $10 million, will increase by 4 times the capacity of the system to collect and destroy the biogas responsible for the odors around the site.

You are invited to download the document at the bottom of this page and to visit the website https://gflenv.com/pierrefonds to learn more about the works and their progress.

Minimize inconvenience
Matrec and the contractors on the site are aware that the works could cause inconvenience for citizens. Unfortunately, the installation of new equipment for biogas collection in the mass of residual materials could occasionally generate odors around the site. Trucking in the area may also increase at certain times in the coming months. We are very sensitive to this situation and will do everything we can to minimize the impact on the neighborhood.

Government authorities having identified the residual materials management industry as an essential service in the context of the pandemic, Matrec is able to carry out the works to close the Pierrefonds site. Rest assured that all measures will be taken to prevent the risk of spreading and to ensure the safety of workers and those who will have access to the site.

Questions and comments
If you have any questions or concerns regarding the work at the Pierrefonds site, please contact 514 696-4509 or write to [email protected]

Please download the PDF document for more information on the site closure works.                                Download PDF

Pour la version en français cliquez ici.