The discharge of saline water in Melvin Bay started on August 10th, 2020 and was compliant with our regulations. Weekly sampling of the water was conducted at the output of the truck, prior to discharging to Melvin Bay, and were analyzed by an accredited external laboratory.

Upon receipt of sampling results on August 31st, it was observed that TSS level for the discharge of August 23rd had exceeded the regulatory limit.

The discharge to sea was stopped immediately, and the TSS exceedance was reported to the authorities on the same day.

The initial estimated volume of water released between sampling dates of August 16th and August 31st was approximately 11,000 m3.

However, following receipt of more results, it was found that a maximum of about 8,000 m3 of water was discharged into Melvin Bay.

The investigation showed that the exceedance of TSS is probably due for the most part to algae developing in the pond used to hold treated water before it is being trucked to Itivia to be discharged in Melvin Bay. An intermittent filter malfunction from the saline pond may have contributed to the exceedance of TSS. Since the filter malfunction was found to be intermittent, the quantity of water with an exceedance of TSS level is expected to be lower than the reported maximum quantity of approximately 8,000 m3 discharged in that period.

Our standard monitoring program in Melvin Bay  showed that the impact of this event on Melvin Bay was minimal.

An action plan including mitigation measures was immediately put in place on August 31st:

  • The pond was fully emptied, rinsed and cleaned by September 8th;
  • Our water discharge process is being audited by an external expert on site to further validate it;
  • The sampling frequency will be increased with daily samples in multiple locations of the process to ensure the compliance of the water;
  • Those daily samples will be analyzed on site to avoid delays in sampling results, in addition to the external weekly analysis made by an external accredited laboratory;
  • Instrumentations to monitor the filters have been installed enabling us to detect any anomaly quickly;
  • Filters will be replaced at a higher frequency.

Agnico Eagle is confident that the measures that were implemented to understand and correct this situation that led to this exceedance have improved the robustness of our system and will be effective. Since the implementation of these mitigation measures, the level of TSS are back within the approved limits. Therefore, the discharge that was stopped since August 31st is planned to resume on September 13. These mitigation measures will remain in place for the remainder of the discharge season.

 

To learn more about our saline water management…

At Meliadine Mine, the saline water that is naturally found underground is released during underground operations. Once released, it is treated on site through the treatment plant, stored into a saline water pond and transported by truck to Itivia where it is released into Melvin Bay.

TSS (Total suspended solids) consist of particles suspended in water but not dissolved of such as dust and organisms such as plankton and algae.