Water treatment system for construction of new subway train sets in Montreal

Location Montréal, Canada
Year 2018
Capacity : 50m³/hour

Challenges

Construction of an underground garage to accommodate the new subway train sets in Montreal.

The drainage water quality is variable and unpredictable and is subject to specific and particularly restrictive criteria.

During the winter season, the water to be treated from the underground excavation is very cold and presents an additional processing challenge.

Presence of water additives such as foamers, solvants and residual concrete add to the treatment challenges.

Given the urban character of the site, the available space for water settling is very limited.

Outcomes

Significant reduction in the use of settling ponds, from 20-30 containers stacked in parallel to only 3, representing a cost saving of 500 000$ over a two-year period.

Restoration of the settling pond will allow the  establishment of administrative and engineering offices, providing faster access to construction site for the teams, increasing productivity on site coordination.

Reduction of the amount of water used for drilling and dust control activities.

A 80% reduction of suspended solids  to the final effluent.