Executive Summary: Key Legal and Evidentiary Issues

• Allocation of construction risk between owner and contractor in light of the MTQ’s duty to inform (obligation de renseignement) versus the entrepreneur’s duty to investigate site conditions and choose methods of work.
• Alleged deficiencies in the MTQ/Stantec plans and devis, particularly the indication of a permanent 5H:1V slope without soutènement temporaire, and the treatment of batardeaux but not sheet piling in the specifications.
• Central role of the LVM geotechnical study and whether, properly interpreted, it made foreseeable the need for temporary shoring, gentler slopes (10H:1V) and alternative drainage methods in silty sand soils.
• Conflicting expert evidence on geotechnical feasibility (assèchement du fond, rabattement de nappe, surface pumping only) and on whether the contractor’s chosen methods or the design omissions caused the instability and batardeau failure.
• Application of the Supreme Court’s Bail framework on the duty to inform, including knowledge of determinative information, its materiality, and the contractor’s legitimate reliance on the MTQ as a sophisticated public owner.
• Quantum of damages tied to non-foreseeable costs (temporary shoring, approach platforms, extra excavation) and partial disallowance of unsupported amounts lacking documentary proof.

Factual background and the bridge replacement project

The dispute arises from a provincial road infrastructure project to demolish and replace an existing steel-and-wood bridge on the Route de la rivière Noire in Saint-Valère, Québec. The Ministère des Transports du Québec (MTQ), represented by the Procureure générale du Québec, issued a call for tenders, and on 3 June 2014 it awarded the main construction contract to Les Excavations H. St-Pierre inc. for $664,999. The contract documents included standard MTQ conditions, plans and specifications, and particularly a geotechnical study prepared by LVM (now Englobe) and appended as Annex 3 to Devis 130.
In April 2015, H. St-Pierre subcontracted essentially all of the physical work to Excavations Mario Roy inc. (EMR), with the knowledge and tacit acceptance of the MTQ, which did not oppose the subcontracting. Supervision of the work was entrusted by the MTQ to WSP, while Stantec acted as designer of the plans and specifications based on the LVM geotechnical study.
The project involved the construction of two bridge abutments (culées 1 and 2). EMR’s planned method for both abutments was the same: work in the dry behind a batardeau, use a surface pump to control water, and excavate with slopes corresponding to those indicated on Stantec’s plans, namely a 5H:1V slope behind culée 2. EMR expressly sought permission to substitute crushed stone MG-56 with “pierre nette” in the structural cushion; Stantec refused at the outset, reasoning that non-compactable clean stone would not provide adequate bearing.
The contractual execution period was eight weeks, while EMR’s own schedule anticipated completion of the work in five weeks. This tight schedule became significant once the practical difficulties of dewatering in silty sand and maintaining slope stability materialised on site.

Execution of the works and the emergence of instability

Work began on 15 June 2015 with demolition of the existing bridge, installation of the batardeau, a surface dewatering well, and some pre-excavation. Almost immediately, EMR encountered instability in the 5H:1V slope behind abutment 2 despite deploying steel plates to distribute loads. The firm ultimately had to soften the slope substantially to about 10H:1V and construct a rock approach platform to allow safe access.
On 17 June 2015, due to this instability, the batardeau began to subside. EMR responded by installing temporary internal shoring within the footprint of abutment 2 to allow workers to approach the planned structural cushion. On 19 June 2015, as EMR aimed to reach the theoretical excavation bottom that day, the batardeau failed, allowing river water into the excavation and dislodging some concrete blocks. At that moment only about one-fifth of the excavation bottom was exposed, and the bottom was far from ready to be approved by the supervising engineer.
Roughly at the same time that day, EMR also encountered a piezometric tube from an earlier LVM borehole; when it was exposed near the bottom of the excavation, significant additional water inflows occurred. Faced with an unstable, water-saturated base, WSP ordered an immediate stoppage of work at the end of 19 June. EMR spent the following days installing more temporary shoring and trying to stabilise the slopes.
A special meeting on 22 June 2015 led to a key design and method adjustment: the MTQ agreed, at EMR’s request, to replace the original MG-56 crushed stone cushion with a combination of lean concrete and clean stone wrapped in geotextile. EMR also proposed further technical solutions on 30 June. On 4 July, EMR’s president dug an exploratory trench near a pump well and discovered that soil conditions became appreciably more stable at about 1.2 metres below the theoretical excavation bottom, at elevation 90.8 m instead of 92 m. Using this lower elevation and a revised cushion design from the MTQ, EMR finally completed the excavation for abutment 2, and the excavation bottom was approved on 7 July 2015. In total, the abutment-2 excavation took around twenty days.
Applying the same revised approach for abutment 1—with very gentle 10H:1V slopes and temporary shoring from the outset—EMR completed that excavation in roughly ten days, with the bottom approved on 17 July 2015. The comparative experience of the two abutments became an important factual benchmark for the court’s causation and foreseeability analysis.

The contractor’s claim and the MTQ’s partial payment

Pursuant to the contract’s notice provisions, H. St-Pierre notified the MTQ on 30 June 2015 of its intention to claim additional costs for extra work arising from the unforeseen conditions and necessary temporary works. In December 2016, H. St-Pierre submitted a detailed claim for $196,607, covering:

• Temporary shoring structures required to stabilise slopes;
• Construction of rock approach platforms tied to those shoring systems;
• Costs associated with the revised structural backfill solution (lean concrete plus clean stone in lieu of the original crushed stone).
  On 18 February 2016, the MTQ accepted only the portion relating to the modified backfill (lean concrete and clean stone) and paid $38,727, later formalised by an amendment in October 2017. The balance remained contested. In October 2019, H. St-Pierre commenced proceedings in the Superior Court of Québec, claiming $176,233.20—the unpaid portion of what it said were non-foreseeable additional costs.

Legal framework: duty to inform and allocation of risk

The court framed the dispute squarely within Québec’s civil law principles on the obligation d’information (or duty to inform), which flows from the overarching duty of good faith in contractual performance under articles 6, 7 and 1375 of the Civil Code of Québec. In the construction context, jurisprudence (including the Supreme Court’s decision in Banque de Montréal c. Bail and more recent cases like Construction BSL inc. c. PGQ) has articulated three elements of this duty: the debtor’s knowledge (actual or presumed) of the information; the determinative nature of that information; and the creditor’s inability to obtain it or its legitimate reliance on the debtor.
In parallel, the court reiterated the fundamental rule that contractors generally bear the execution risk of difficulties that they ought reasonably to have foreseen when bidding. They must carefully verify the work, its complexity, site conditions, and select their methods accordingly. They cannot later rely on predictable difficulties to escape obligations or seek price increases.
However, public owners like the MTQ have a countervailing obligation: they must describe the proposed work with sufficient care and precision to allow bidders to understand what is expected and to evaluate their price and risk. The owner cannot conceal or fail to communicate determinative facts that would influence the decision to contract, the conditions of contracting, the nature of the work, or the manner of performing it. Moreover, the design of the works—entrusted here to Stantec—is ultimately the owner’s responsibility. Inaccuracies or omissions in the plans and specifications may mislead contractors and support claims for extra costs when additional work is required.

Key contractual and technical documents at issue

The LVM geotechnical report was central; it described existing soil and groundwater conditions, measured groundwater level, and provided comments and recommendations to guide the project’s design. Among other things, it warned of significant water inflows below the river level, highlighted the difficulty of dewatering in silty sand with only surface pumping, and discussed scenarios involving batardeaux and sheet piling (palplanches) to preserve bearing capacity while working in the dry.
Yet, in Devis 130, Stantec specified only the need for batardeaux for the abutment works, treating them as a pay item and directing the contractor to consult the geotechnical study and develop its dewatering methods accordingly. The specifications did not include or even clearly signal the possible need for temporary shoring (such as palplanches) as a separate item, even though the LVM report discussed batardeaux and sheet piles in parallel as tools to work dry and maintain soil bearing capacity below the river level.
The plans also depicted a 5H:1V slope behind the abutments. Despite some debate as to whether this was meant as a temporary or transitional configuration, the designer (Stantec) indicated that this slope was intended to be permanent and the specifications repeated the 5H:1V requirement as a relatively gentle, supposedly stable slope. Importantly, no temporary shoring system was identified alongside this slope in the contract documents. Geotechnical experts for both sides agreed that the actual work ultimately required much gentler 10H:1V slopes and still needed temporary shoring to stabilise the excavation, undermining the reliability of the original design assumptions.

The MTQ’s defence: contractor’s methods and foreseeability

The MTQ’s core defence was that the difficulties stemmed from EMR’s own choice of method: the contractor allegedly failed to heed the LVM study and should have dewatered the excavation base and lowered the water table before commencing excavation. According to the MTQ, this would have required some waiting period (estimated by some witnesses as two to three weeks) but still permitting the contractor to meet the eight-week contractual schedule.
On the MTQ’s account, the 5H:1V slope specified on the plan was only a transition slope, not a guarantee of stability. The failure of the batardeau, the remobilisation of soil, and the additional water caused by the exposed piezometer were said to be consequences of EMR’s inadequate methods and timing, not of any design flaw. Given that the LVM report correctly described soil conditions, the MTQ argued that the conditions encountered were foreseeable, and any extra cost was part of the contractor’s assumed risk.

Expert evidence and credibility findings

A considerable evidentiary contest unfolded through four expert reports and testimonies. For the plaintiff, engineer Marc Bujold quantified the claim and commented on site conditions and foreseeability, while veteran geotechnical engineer Raymond Juneau opined on soil behaviour, slope stability, dewatering feasibility and the adequacy of the plans and specifications. For the MTQ, in-house engineer Priscilla Desgagnés produced a geotechnical critique, and consultant Jean Comeau assessed both quantum and geotechnical foreseeability.
The court found all experts generally credible but accorded the greatest weight to Juneau, who had over five decades of experience, formal advanced training in geological engineering, and substantial prior recognition as an expert across many cases, including mandates for the MTQ itself. Bujold, though not a geotechnical specialist by training, was considered competent on field execution issues, water management, piling and quantification of damages; his strictly geotechnical counter-expertise was given lesser weight but his first report on quantum and practical conditions was accepted.
By contrast, the court viewed Desgagnés’s and Comeau’s opinions through the lens of their close institutional ties to the MTQ. Desgagnés had spent her entire career at the department and had never testified as an expert before; Comeau derived about 90% of his mandates from the MTQ. This relationship did not disqualify them but did temper the probative value of their conclusions where they diverged from the more independent experts.

Court’s analysis of dewatering and shoring options

On the contested issue of whether EMR should have dewatered and lowered the water table in advance, the court accepted the thrust of Juneau’s and, to a large extent, Desgagnés’s evidence: while such a method was theoretically possible, it was not practically realistic in the context of silty sand soils and tight project timelines. Only surface pumping was feasible, and the duration required for effective drawdown was uncertain and potentially as long as a month, with no assurance of achieving a sufficiently dry and stable base.
All of the main experts, including Desgagnés for the MTQ, converged on the conclusion that only surface pumping was viable in these ground conditions; deep wells or wellpoints were not suitable. This convergence supported EMR’s assessment that relying solely on advance dewatering (instead of physical support) was not a sound or predictable method within the contractual time constraints.

Design omissions, misleading indications and the duty to inform

The court ultimately found that the decisive problem lay not in EMR’s methods, but in the omissions and misleading indications in the MTQ/Stantec design as informed by the LVM report. First, in light of the LVM study’s explicit warning of significant water inflows and the discussion of both batardeaux and sheet piles, Stantec should have clearly contemplated the possible need for temporary shoring (e.g., sheet piling) in the specifications and, if appropriate, in the bill of quantities, just as it did for batardeaux. Treating batardeaux as a pay item while remaining silent on shoring wrongly suggested that batardeaux alone would suffice to manage both water and soil stability.
Second, the incorporation of a 5H:1V slope into the plan and specifications, without any explicit indication that it was a non-stable or provisional geometry, reasonably led a contractor to assume that such a relatively gentle slope would be stable under expected conditions, particularly when no temporary shoring requirement was highlighted. The fact that, in reality, EMR had to flatten the slopes to 10H:1V and still install shoring in order to execute the works safely and successfully showed that the original design was not suited to the actual soil and groundwater conditions.
Third, the MTQ’s initial refusal to permit clean stone in lieu of MG-56 crushed stone in the cushion exacerbated the stability and water-control problems. Juneau identified this as a key factor: using clean stone from the outset would have contributed significantly to stabilising the base and controlling inflows. The MTQ’s later acceptance of this solution, reflected in an amendment and partial payment, corroborated its technical merit and underscored that earlier insistence on MG-56 had made conditions more difficult than necessary.
The failure to flag the realistic need for shoring, combined with the representation of a 5H:1V slope as the design standard and the initial stance against clean stone, collectively induced the contractor to underestimate the true difficulty and cost of the work. In the language of Bail, these were determinative pieces of information within the MTQ’s knowledge (through its designers and geotechnical consultants), not reasonably accessible to the contractor at tender stage, and on which the contractor legitimately relied given the MTQ’s status as Québec’s largest public contracting authority.

Causation, the batardeau failure and the piezometric tube

The MTQ tried to attribute the bulk of the trouble to the 19 June 2015 batardeau collapse and the coincident discovery of the piezometric tube. The court acknowledged that these events complicated the work, requiring a lower final excavation elevation (90.8 m instead of 92 m) and additional water management. Nevertheless, it characterised them as secondary, downstream events rather than root causes.
In the court’s view, the batardeau failed because there was no temporary shoring in place, a situation that traced back directly to the deficient information and misleading design. Had shoring been properly anticipated and installed from the start—as EMR did at abutment 1 once problems had been experienced—the batardeau would likely not have collapsed, or the consequences would have been far more limited. Likewise, although the exposed piezometric tube contributed to water inflow, it did not fundamentally change the nature of the soil conditions that the LVM study should have translated into clear shoring indications and revised slope requirements.
The court therefore held that the primary cause of the non-foreseeable extra work and costs was the MTQ’s breach of its duty to inform through deficiencies in the plans and specifications, not any negligence in EMR’s methods.

Conclusion on liability and the duty to inform

Synthesising the evidence, the judge held that the MTQ failed to satisfy its obligation to inform as defined in Bail and subsequent case law. The omission to address temporary shoring in the specifications and the inaccurate depiction of a stable 5H:1V slope misled the contractor about the foreseeable conditions and necessary means of execution. These were determinative pieces of information about which the MTQ, via its designers and geotechnical consultant, was or should have been aware, and that a reasonably diligent contractor could not fully uncover during bidding.
Given the MTQ’s stature as a sophisticated, repeat public owner, H. St-Pierre was entitled to place legitimate reliance on the accuracy and completeness of its design documents. The court concluded that the MTQ’s breach of its duty to inform constituted a fault engaging its civil liability for the non-foreseeable extra costs borne by the contractor.

Assessment of damages and financial outcome

On quantum, the plaintiff sought essentially the extra costs of temporary shoring, related approach platforms, and additional excavation linked to the need for 10H:1V slopes. The court found these categories of cost to be justified, and it preferred Bujold’s methodology for quantifying them, particularly once it had determined that the underlying conditions were not foreseeable and therefore fell outside the contractor’s assumed risk.
The court did, however, trim the claim by approximately $10,643.89, representing amounts for which no supporting documentation was produced, even though EMR’s representative explained that some records had not been preserved because the claim was assembled over a year after work completion. Since this portion was not adequately substantiated, it was deducted from the total claim.
After this adjustment, the court fixed the plaintiff’s recoverable claim at $165,589.31. It ordered the Procureure générale du Québec, on behalf of the MTQ, to pay this amount to Les Excavations H. St-Pierre inc., together with interest and the additional indemnity from the date of service of the proceedings. The judgment also awarded costs in favour of the plaintiff, including the fees of experts Juneau and Bujold for their main reports and testimony, but excluding the portion of Bujold’s fees attributable to his geotechnical counter-expertise, which the court deemed not useful to resolving the dispute. The precise total of interest, additional indemnity and taxable costs is not quantified in the judgment and would be determined at the taxation stage, but the clear successful party is Les Excavations H. St-Pierre inc., with a principal monetary award of $165,589.31 plus unquantified interest, additional indemnity and most of its expert and court costs.