Alamos Gold Inc., Young-Davidson Mine: Water Treatment Plant Project


The design, construction and commissioning of a 1500 m3/day water treatment system within an existing gold processing operation. The project is located in Matachewan, Ontario, Canada.

The Challenge:

To circumvent filling the tailings pond with mine water, the client sought to treat the mine water effluent and discharge the treated water to a nearby river in accordance with strict local regulations.
The foremost challenge of the brownfields engineering and construction of the water treatment system was designing within the confines of existing infrastructure and tying the system into the operation without affecting or interrupting production.

Halyard Scope:

EPC, construction assistance and commissioning of the water treatment system.


Multiple water treatment methods were evaluated and on the basis of capital cost, operating cost and performance, a treatment method was selected to be applied to the overall water treatment system.

To integrate the treatment system into the existing production, tanks, pumps and overland pipelines were sized and specified to transport effluent, sludge and treated water from around the mine site to their respective discharge points.

Planning and scheduling of the project was critical to ensure the civil foundations for a 300 m3 tank would be completed prior to the ground freezing during winter.

In the interest of capital cost savings, several existing pieces of equipment and assets were integrated into the design of the water treatment system. For example, instead of supplying new lime and polymer make up systems as per the package plant vendor’s proposal, Halyard managed to design a system whereby these were piggybacked off the existing systems to eliminate these items from the project. Similarly, unused space in the existing Motor Control Centres were used instead of supplying a new MCC. By successfully making use of existing equipment, not only were cost savings evident, but this assisted with keeping the footprint of the new system to a minimum.


Constructive site visits enabled the design of the treatment system to be laid out in a resourceful manner. Decisions to repurpose existing equipment pedestals and position tanks to minimize pipelines assisted with keeping costs to a minimum and simplifying construction and maintainability of the treatment system.

Effective planning allowed for the civil foundations to be constructed prior to the on-set of winter conditions. This allowed for the erection of the 300 m3 tank to occur without delay.

Efficient commissioning of the water treatment system was achieved by managing multiple contractors and vendors on site to keep progress on track and within budget.