Route 136/Turcot – Update on the sound barrier court case

On May 1, 2017, the City of Westmount initiated legal proceedings against the Ministère des Transport du Québec (MTQ) and its contractor KPH Turcot regarding noise generated by Highway 136. The City of Westmount claims that during the final design of the project, the MTQ and KPH significantly increased the level of Highway 136, in contravention of the plans that had been approved by decree by the Quebec government (decree 890-2010). As a result of this contravention, the representation made to the City of Westmount during the project approval process, to the effect that the new project would improve overall noise levels, could not be met. To remedy this contravention of the decree, the City of Westmount requested that the MTQ and KPH Turcot be ordered to build noise barriers between Glen Road and Atwater Avenue, along Highway 136. The case was suspended several times by the courts, notably during the construction of the interchange.

On May 19, 2022, the Superior Court of Quebec ordered the parties to obtain a joint expertise regarding the quantification of noise climate. The parties retained SNC-Lavalin (now Atkins Realis) to carry out this assessment. The assessment was made in the fall of 2022, and the report – which requires several modeling operations – has yet to be delivered. It should be completed in the summer of 2024.

In parallel with this case, the City of Westmount is also challenging, before the Superior Court, the Ministère de l’Environnement du Québec’s decision concerning the “one-year post-project delivery” noise assessment, which the MTQ is required to carry out under decree 890-2010. Indeed, the MTQ must carry out an assessment of the noise impact of the new Highway 136, one, five and ten years after its commissioning. If the noise level exceeds the level which prevailed before the project, the MTQ is then required to implement noise mitigation measures, at its own costs.

However, in a decision dated October 23, 2023, the Ministère de l’Environnement determined that the results transmitted by MTQ – which indicate that noise levels have not increased compared to the situation before the project – “are based on a large number of hypotheses, which are difficult to validate” and, consequently, that it “is not possible to comment on the acceptability of the results or conclusions”. Despite these clear findings, the Ministère de l’Environnement concluded that the MTQ had met its obligations regarding the assessment “one-year post-delivery”, while recommending more rigorous noise monitoring for the “five-year” follow-up.

The City of Westmount finds the Ministère de l’Environnement’s decision unreasonable. The Ministère cannot, on the one hand, determine that it was impossible to rule on the acceptability of the MTQ’s results, and yet conclude that the MTQ had fulfilled its obligations satisfactorily. The decision is therefore incoherent and implies that the citizens of the City of Westmount will have to wait a further four years for the MTQ to fulfill the obligations it had to fulfill from Year 1. The City of Westmount is asking the Superior Court to overturn this decision.