The Green Line LRT project is progressing through the Development Phase as we continue to get closer to main construction of tracks, stations, tunnels, and bridges. Before construction begins, our Development Partner, BTC, will undertake additional due diligence work to test ground conditions through a series of geotechnical and environmental borehole drilling exercises.
Testing will take place in October and November 2023, with locations along Phase 1 of the Green Line alignment (Shepard to Eau Claire).
Geotechnical due diligence involves investigating the ground before we build on or tunnel through it.
- Understanding the soil and rock materials present.
- Determining the properties of the ground (e.g., hard or soft, clay or gravel).
- Testing permeability (how much water can flow through the ground).
- Confirming the ground water table elevation and how it fluctuates over time.
Environmental due diligence involves collecting soil and ground water samples and analyzing them for contaminants.
- There are known contaminated sites along the alignment where we anticipate finding diesel, gasoline and degreasing solvents in the soil.
- Other common contaminants include metals and salt from road de-icing.
- By identifying contaminants, we can determine how to manage them during construction, and how to properly handle the material.
Both geotechnical and environmental tests involve drilling boreholes into the ground, collecting samples, then analyzing the material. More than 672 boreholes and test pits have been drilled since 2014, so we already have a lot of information about the ground and what we can expect.
The information we find now will help us remove elements of risk from the project, design the best structures for the soil/rock conditions, and better estimate project costs.