This is a response to an opinion piece written by the SkeenaWild Conservation Trust called “The forces of yes according to Greg Knox” and published June 22, 2016.
It stated, “… we do have serious concerns about tailings dams being constructed in the same manner as Mount Polley, as is proposed for the Seabridge Gold project.”
This statement is factually incorrect. The selected tailings management design for the Kerr Sulphurets Mitchell (KSM) project northwest of Stewart is the best available tailings technology (BATT) to account for the site specific characteristics present in northwestern B.C. and is designed to promote both physical and chemical stability of the waste material.
All potential tailings disposal methods including dry stack and wet disposal methods were reviewed and assessed as a requirement of the recently completed independent Environmental Assessment (EA) process for the project.
Specifically, the KSM tailing management facility (TMF):
• Underwent a comprehensive environmental assessment process and the TMF design was changed to reflect input from local First Nations and regulators.
• Is located in a confining valley with cross valley dams situated at each end;
• Will consist of simple cyclone sand dams at a 3:1 slope with one kilometre of dry beaches between the water and the dam, thus minimizing the impact of water within the impoundments
• Has a process and design which allows for discharge from the TMF, thus preventing a buildup of surplus water within the TMF; and
• Used 30-day flood event as the design basis for the facility which will result in 12m of freeboard (the height from the water level to the top of the dam) within the TMF.
Additionally, Seabridge has established an Independent Geotechnical Review Board (IGRB) to provide independent, expert oversight, opinion and advice to Seabridge on the design, construction, operational management and ultimate closure of the tailings management facility and water storage dam.
The initial IGRB review of Seabridge Gold’s KSM Project design was conducted in March 2015 and was developed to answer five questions:
(1) Are dams and structures located appropriately;
(2) Are dam sections, materials, construction methods and sequencing appropriate for the site;
(3) What are the greatest design, construction and operating risks;
(4) Are the facilities designed to operate effectively, and;
(5) Are the facilities designed to be safe?
The board concluded it was satisfied with the project’s designs and responded favourably to all five questions. Additionally, the board presented a series of recommendations for Seabridge to consider during the ongoing engineering design of the KSM Project as development continues.
Seabridge Gold has made publicly available on our website (www.ksmproject.com), a significant amount of information about its proposed KSM project’s tailings management facility, including the IGRB’s report. We encourage anyone who has questions about the project to view our website.
R. Brent Murphy, P.Geo
Seabridge Gold, Toronto, Ontario