Public information session on the Soil rehabilitation plan

The MPA invites the public to participate in a virtual information session to present a summary of the characterization studies, toxicological and ecotoxicological risk assessments, groundwater impacts and rehabilitation plan prepared for the Port of Montreal overpass and access road construction project on land owned by the Ministère des Transports du Québec (MTQ).

This land is located north of Notre-Dame Street between the existing roundabout and the CN Longue-Pointe rail yard, in the municipal borough of Mercier-Hochelaga-Maisonneuve in Montreal (part of lots 1 360 268 and 1 560 077).

In accordance with section 31.54 of the Environment Quality Act (EQA) brought about by the change in the use of land, the MPA has submitted a rehabilitation plan to the Ministère de l'Environnement et de la Lutte contre les changements climatiques (MELCC) that provides for land with contaminants in a concentration exceeding the regulatory limit values found in the Land Protection and Rehabilitation Regulation, mainly manganese and one case of zinc as well as non-volatile polycyclic aromatic hydrocarbons (pyrogenic) associated with ash and bottom ash. This rehabilitation plan is accompanied by toxicological and ecotoxicological risk assessments together with the impacts on groundwater.

In light of the studies carried out, and taking into account that contaminated backfill remains in place, the following capping measures are proposed:

• Under areas such as paved surfaces that are designated as "permanent," a minimum thickness of 40 centimetres (0.4 m) of clean soil (soils with concentrations lower than criteria A of the Guide d’intervention) is planned;
• Under landscaped areas, a one-metre surface cover of clean soil (soils with concentrations below Criteria A of the Guide d’intervention) is planned to protect ecological receptors;
• Around existing mature trees, a protection radius will be determined for each tree based on its species and size (diameter) as per BNQ 0605-100 (the standardization bureau of Quebec’s norm for landscaping with plants) to preserve their root system. Within the critical root zones for groups of trees, a 30cm cover of clean soil (soils with concentrations lower than criteria A of the Guide d’intervention) will be put in place.

The proposed measures are taken from the recommendations of the MELCC Technical Assessment Group Guidelines.

The party responsible for this publication is the Montreal Port Authority in accordance with the provisions of section 31.55 of the EQA.