To move ahead with the Lac-Mégantic Rail Bypass Project, an application for authorization of construction must be submitted to the Canadian Transportation Agency in accordance with section 98 of the Canada Transportation Act. Transport Canada and the railway operator are currently preparing the necessary documentation to submit the application to the Canadian Transportation Agency for the bypass project.
A public consultation on the hydrogeological study was held in October and November 2022. During this consultation, the public provided feedback on the study, including the ways the project could impact groundwater and wetlands, and the mitigation and follow-up measures that could minimize those impacts.
Following the consultation, the project developed a wetlands monitoring plan and a groundwater and potable water well monitoring plan. The hydrogeological study was updated with the most recent field data and based on feedback received. To finalize the application, the project is providing another opportunity for feedback on three documents: the updated Hydrogeological report, the Wetlands Monitoring Plan, and the Groundwater and Potable Water Well Monitoring Plan.
On this page:
- Hydrogeological report
- Wetlands monitoring plan
- Groundwater and potable water well monitoring plan
- Contact us
- Related links
Hydrogeological report
This report is an updated version of the existing hydrogeological study. This study assessed the hydrogeological properties of the aquifers (masses of porous rock or sediment saturated with groundwater) present in the area of works, specifically where soil and rock will need to be excavated during the construction of the bypass. The updated report explains how the maximum radius of influence was assessed to design and implement a monitoring program at locations where impacts might be observed.
Summary of the hydrogeological report
A hydrogeological study looks at how groundwater gets into the ground, how it flows in the subsurface and how groundwater interacts with soil and rock. This study is usually required for projects that have the potential to affect groundwater or change how it flows.
In view of the potential impact on groundwater by the construction of the future Lac-Mégantic rail bypass, the railway operator, Canadian Pacific Kansas City (CPKC) hired the Englobe firm to prepare a hydrogeological report. This report explains the hydrogeology of the area where the future bypass will be built and describes the properties of the aquifers (masses of porous rock or sediment saturated with groundwater) in the areas that will need to be excavated to build the bypass.
The first version of this study was submitted in 2022, and then updated in 2024. The new version includes data from Englobe's well water level surveys from October 2021 to February 2024. The new data shows how water levels in the study area vary over time and gives a better idea of which areas could be impacted by construction, reducing the estimates from the previous report.
The 2022 consultation’s feedback revealed that the main concern expressed was the impact construction could have on water quality and quantity of private wells. Participants expressed concerns about water table levels, potential contaminants, action levels for water quantity issues and when new wells would be drilled, if deemed necessary.
Hydrogeological profile
The future bypass will be located in the municipalities of Frontenac, Lac-Mégantic and Nantes. The results of the hydrogeological study only apply to the sections of the selected rail route. Most of the proposed route passes through woodland, farmland or sparsely populated areas. Englobe identified 5 different excavation sectors because of their different hydrogeological and topographical (physical) properties.
Observation wells were installed in 2021, and water levels were monitored constantly from October 2021 to February 2024. Englobe also carried out pressure tests on a number of wells. Based on this data, Englobe defined a zone in each sector where groundwater levels could be affected by construction (zone of influence).
Hydrogeological properties of aquifers and potential impacts
The report explains that there is a connection (hydraulic connectivity) between groundwater and parts of the water table (where pores and fractures of the ground are saturated with groundwater) like wetlands, bodies of water and drinking water wells. The report found that wetlands next to the bypass’ planned right-of-way could be affected by construction.
These impacts will depend on a number of factors, like whether or not the water table lowers. The drawdown caused by drying activities could have indirect consequences on wetlands and runoff waters in the excavation influence area. This will happen if runoff waters are related to the aquifer or if their runoff water supply is modified.
General recommendations
The report includes general recommendations that relate to the site’s hydrogeological conditions, like:
- using caution when designing water management systems
- taking all types of wetlands into account when assessing environmental effects, and
- implementing a groundwater monitoring network
Finally, the report presents recommendations for the construction of the railway line and related structures (like the bridge over the Chaudière River, the pedestrian tunnel and the embankments).
Request a copy of the full hydrogeological report.
Wetlands monitoring plan
Transport Canada committed to implementing a Wetlands monitoring plan, with the objective to describe the initial state of wetlands before construction, to monitor the evolution throughout the construction work, and for up to 10 years following the work completion. The Wetlands monitoring plan has been developed as a key part of the project’s commitment to monitor and mitigate the environmental impacts on the wetlands located outside the rail bypass’ right-of-way.
Summary of the wetlands monitoring plan
The studies carried out to date show that the project will potentially impact wetlands located outside the future right-of-way. One way to reduce the project’s environmental impact is by monitoring wetlands located outside the future right-of-way. The data collected will help track changes through time in those wetlands and assess the impacts and possible losses caused by construction.
The indicators we will monitor are recognized by both the federal and provincial departments of the environment. These indicators include:
- site descriptions (including potential disturbances)
- water levels in well point
- soil (profile and composition)
- vegetation description (species and abundance)
Monitoring
We looked at each area that will be excavated and installed well points in order to monitor any changes to the water table during, or after, construction.
During construction, we will monitor wetlands and water levels in spring and fall. Once construction ends, we will continue these assessments in years 3, 5 and 10.
Compensating for lost wetlands
Transport Canada will contribute to the Fonds de protection de l’environnement et du domaine hydrique de l’État to make up for any wetlands lost during construction within the right-of-way. This compensation will be reviewed once the monitoring period ends and might be adjusted based on the final number of wetlands outside the right-of-way affected by construction.
Request a copy of the full Wetlands monitoring plan.
Groundwater and potable water well monitoring plan
Transport Canada is committed to ensuring that every citizen has potable water for their daily consumption and activities before, during and after construction until the water table stabilizes. To reduce the potential impacts on residential drinking water wells, the Laforest Nova Aqua hydrogeology firm developed a Groundwater and potable water well monitoring plan for concerned and potentially affected residents. The wells included in the plan are located in areas that could be affected by construction.
Summary of the Groundwater and potable water well monitoring plan
The Lac-Mégantic rail bypass construction project involves excavation, blasting and dewatering work in several areas. This work will likely impact groundwater. The dewatering work could lower the water table. This could reduce the amount of water in the aquifers that the private wells near the excavation areas get their water from. The blasting work may affect the fracture networks in the rock aquifer. This could impact the quantity and quality of water in potable water wells.
Goals of the Groundwater and potable water well monitoring plan
Transport Canada made a commitment to maintain adequate water quantity and quality for everyone affected by the construction of the bypass through a “groundwater and potable water well monitoring” program. To do this, the hydrogeology firm Laforest Nova Aqua (LNA) developed the Groundwater and potable water well monitoring plan (GPWWMP). The plan was commissioned by the municipalities of Frontenac, Lac-Mégantic and Nantes. Since most of the wells it will monitor are fed by groundwater, this plan also involves a groundwater monitoring program.
After the November 2022 public consultation, Transport Canada adopted 9 additional mitigation measures to reduce the Project's potential impacts on residential potable water wells. Between 2022 and 2023, 3 more field studies were carried out to make a list of residential potable water wells in the areas affected by the work.
The GPWWMP is based on the most recent data available and reports, including:
- the inventories and characterizations of residential potable water wells done by WSP, Arrakis and Laforest Nova Aqua since 2022
- Golder’s environmental impact assessment
Methods
The GPWWMP is divided into 3 phases:
- Initial phase, which involves a risk analysis before starting any work
- Construction phase, which involves managing the risk during the works by setting intervention thresholds (when and how to act to protect groundwater)
- Operation phase, which involves monitoring the wells for at least 2 years after the works are completed and until the water table and water quality is stable.
Water quantity and quality data were collected following a standard for each well listed during field studies between 2021 and 2023. This data was used for a risk analysis of both water quality and quantity for wells on either side of the future rail bypass. Wells were divided into 3 estimated risk levels (low, medium and high) depending on the planned work. These categories will help to plan the level of monitoring needed (like the types of equipment, and how often samples are taken) in a targeted way.
The equipment and monitoring that will be put in place will let us constantly reassess risk during construction, right through to the operational phase. This flexibility will allow monitoring measures to be adjusted according to the data collected during the project.
There are intervention thresholds for each inventoried well. The thresholds will let us prevent problems and act before a homeowner runs out of water or the water quality of the well deteriorates. There are 4 possible thresholds: green, yellow, orange and red. Each level represents how much impact there has been on water quantity or quality. They also include triggers for moving between levels. The GPWWMP clearly defines the actions to be taken if necessary, including what to do, who will do it and how.
The GPWWMP provides for monitoring to begin before construction of the bypass begins. It will also continue for at least 2 years after the work is completed or until the water table is stabilized.
An oversight committee made up of representatives from the three municipalities will meet monthly to supervise the GPWWMP manager. One municipality will take the lead on behalf of the three municipalities in managing the plan’s implementation. The GPWMMP manager will produce an annual report.
This plan was developed by the hydrogeology firm Laforest Nova Aqua (LNA), working on behalf of the municipalities of Lac Mégantic, Frontenac & Nantes. The plan will form the basis of Transport Canada’s commitments to residents regarding how ground and well water risks will be managed for the rail bypass project. This plan is informed by various inputs and will be finalized once the consultation is completed.
Request a copy of the full groundwater and potable water well monitoring plan.
Contact us
Transport Canada
Place de Ville, Tower C
330 Sparks St.
Ottawa ON K1A 0N5
Phone: 819-237-9475 (between 8 am and 4 pm)
Email: TC.InfoLacMegantic.TC@tc.gc.ca