Energy and Climate Solutions
Minister of Energy and Mines Bill Bennett has announced that government will act immediately on key recommendations of the independent panel that investigated the Mount Polley tailings storage facility (TSF) failure and launch a code review to consider the other recommendations.
The Chief Inspector of Mines will require all operating mines with TSF dams to provide a letter by June 30, 2015, to confirm whether foundation materials similar to those at Mount Polley exist below any of their dams. If those materials are present, the letters must also confirm whether sufficient investigations and testing were completed to properly understand the strength and location of those materials and that the dams were designed to account for those conditions.
The Province will also move to implement a new requirement that all operating mines with TSFs in British Columbia establish Independent Tailings Dam Review Boards. These boards will support improved engineering practices by providing third-party advice on the design, construction, operation and closure of TSFs. Some mines in B.C. already have similar boards in place.
Lastly, the Province will initiate a code review to determine how to best implement the panel’s remaining recommendations, including the adoption of best available practices and technologies.
(flickr.com) These actions respond to the panel’s report which determined that the strength and location of a layer of clay underneath the dam was not taken into account in its original design. As a result, this layer became overstressed, causing the portion of the dam on top of that layer to collapse.
Today, the Province also released the inspections and third-party reviews of TSFs at other permitted mines in British Columbia, ordered by the Chief Inspector of Mines following the failure at Mount Polley. The inspections and reviews have not identified any immediate safety concerns and are available online at: http://bit.ly/1ABYxVs
The Province is investing in improved information systems so that this information can routinely be made public going forward.
The inspections included site investigations, interviews with TSF operators and reviews of instrumentation and monitoring data. In addition to submitting inspection reports and third-party reviews, companies also submitted a letter of commitment to the Chief Inspector outlining how they plan to implement any recommended work.
Quote:
Bill Bennett, Minister of Energy and Mines and Responsible for Core Review -
“I am relieved to know the cause of the failure at Mount Polley and want to thank the panel for their important work. Now we can devote all of our energy to taking a leadership role in Canada and internationally to learn from this and ensure it never happens again.”
Learn More:
A copy of the independent panel report is available online here: https://www.mountpolleyreviewpanel.ca/
Three backgrounders follow.
Media Contacts:
Jake Jacobs
Media Relations
Ministry of Energy and Mines and Responsible for Core Review
250 952-0628
BACKGROUNDER 1
Regulatory requirements
Tailings are a mix of water and material consisting mostly of ground rock, produced during the mechanical and chemical processes that are used to extract the desired product from the mine ore. The tailings used during the extraction processes are discharged to the TSF.
Regulatory requirements for tailings storage facilities (TSFs) in British Columbia are set out in Part 10 of the Health, Safety and Reclamation Code (Code) which includes references to the Canadian Dam Association, Dam Safety Guidelines (CDA Guidelines).
Health, Safety and Reclamation Code for Mines in B.C.
Part 10 of the code includes requirements that:
- TSFs must be designed in accordance with CDA Guidelines.
- TSFs must be designed by a professional engineer.
- The stability of the TSF embankments must meet CDA Guidelines.
- Operations cannot begin until an “as-built” report is prepared by a professional engineer certifying that the facility was designed and constructed to CDA Guidelines.
- Dam safety inspection reports must be prepared annually by a professional engineer and submitted to the Chief Inspector of Mines.
- TSFs with a consequence classification between High and Extreme must have an Emergency Preparedness Plan.
Canadian Dam Association, Dam Safety Guidelines
CDA guidelines cover all aspects of the design, construction and operation of TSF dams. The guidelines include direction on the geotechnical practices that should be followed to ensure TSFs are designed, constructed, operated and maintained safely.
The guidelines state that a geotechnical site investigation, including drilling and sampling, should be carried out to determine the strength and location of foundation materials.
The stability of a dam is typically determined by calculating a “factor of safety” that shows how much stronger the dam is than it needs to be to support its intended load. As the height of a dam is raised, more materials are added to it to maintain an appropriate factor of safety.
The factor of safety calculation is based on the foundation materials and the materials in the dam. It depends upon obtaining reliable information about the strength and location of these materials at the original design stage, verified by investigations and tests.
Media Contacts:
Jake Jacobs
Media Relations
Ministry of Energy and Mines and Responsible for Core Review
250 952-0628
BACKGROUNDER 2
Mount Polley Investigations
Independent Engineering Investigation
On Aug. 18, 2014, government ordered an independent engineering investigation into the cause of the Mount Polley tailings storage facility (TSF) failure.
The investigation was authorized under Section 8 of the Ministry of Energy and Mines Act and an independent panel of geotechnical experts, with the power to compel evidence, was appointed, consisting of: Norbert Morgenstern (Chair), Steven Vick and Dirk Van Zyl.
The panel was tasked with investigating into and reporting on the cause of the failure and making recommendations to government on actions that could be taken to ensure a similar failure doesn’t occur in the future.
The panel was also authorized to comment on what actions could have been taken to prevent the failure as well as practices in other jurisdictions that could be implemented in British Columbia. The panel was authorized to investigate all matters it deemed appropriate.
The panel was instructed to perform its duties without expressing any conclusions or recommendations regarding the potential civil or criminal liability of any person or organization and to ensure that its inquiry did not in any way impede or conflict with the investigations being conducted by the Chief Inspector of Mines or the Conservation Officer Service.
Chief Inspector of Mines and Conservation Officer Service
The Chief Inspector of Mines is responsible for administering and enforcing the Mines Act and the Health, Safety and Reclamation Code for Mines in British Columbia. The inspector’s investigation will determine whether there were any violations of the Mines Act or the Code.
The Conservation Officer Service is the primary natural resource law enforcement agency in British Columbia and enforces over 33 pieces of provincial and federal legislation, including the Environmental Management Act and the Fisheries Act. Its investigation will determine whether any of these laws were violated.
The Chief Inspector of Mines is an independent statutory officer and the Conservation Officer Service is an independent law enforcement body. The investigations are expected to be complete by this summer and will forward recommendations for charges if warranted directly to Crown Counsel.
Media Contacts:
Jake Jacobs
Media Relations
Ministry of Energy and Mines and Responsible for Core Review
250 952-0628
BACKGROUNDER 3
Inspections and independent reviews of tailings ponds at permitted mines
The inspections and third-party reviews of tailings storage facilities (TSFs) at other permitted mines in British Columbia, ordered by the Chief Inspector of Mines following the failure at Mount Polley, have not identified any immediate safety concerns.
The inspection reports are available online at:
http://bit.ly/1ABYxVs
The Province is investing in improved information systems so that this information can routinely be made public going forward.
There are currently 98 permitted TSFs with a total of 123 dams at 60 metal and coal mines in British Columbia - 31 of these facilities are at mines that are operating, or under construction. The remaining 67 are at mines that are either permanently closed or under care and maintenance.
Chief Inspector of Mines Order
Under the Health, Safety and Reclamation Code for Mines in British Columbia, permitted mines are required to submit annual Dam Safety Inspections (DSI). A DSI typically involves a visit to the mine, interviews with the facility inspector and operators, visual inspections of the facilities, and reviews of available instrumentation and monitoring data. The annual DSI report should review operation, maintenance and surveillance of the TSF.
On Aug. 18, 2014, the Chief Inspector of Mines ordered that:
- The deadline for 2014 DSIs be accelerated from March 31, 2015 to December 1, 2014.
- Those inspections be reviewed by an independent, qualified, third-party professional engineer from a firm not associated with the TSF.
- The dam’s consequence classification be reviewed by a third party.
- For dams with a consequence classification of high, very high or extreme: the Emergency Preparedness and Response Plans (EPRP) be reviewed and updated as required.
The third-party reviews (TPR) were to include the reviewer’s comments on the overall condition and consequence classification of the dams as well as the reviewer’s recommendations to improve the overall safety of the TSF.
All mines with High to Extreme consequence classifications conducted a Dam Break Inundation Study, and updated and tested their Emergency Preparedness and Response Plans as required by the Chief Inspector of Mines’ orders. Through these exercises, the mine managers and responding agencies have a better understanding of their emergency management procedures and requirements.
The Chief Inspector also ordered that companies submit letters:
- Outlining commitments for completing the recommended work proposed in the DSI and TPR reports, along with a schedule for implementing that work.
- Summarizing their Emergency Preparedness and Response Plan test and any identified gaps and lessons learned from that test.
The Ministry of Energy and Mines subsequently retained Hatch Ltd. to:
- Assist with reviewing all submissions to ensure consistency and compliance;
- Prepare a summary report.
- Establish a platform to release all submissions to the public.
Exemptions and Extensions
While the Chief Inspectors’ order was issued to 60 mines, five mines were exempted and four mines were granted extensions. The compressed timeframe to provide these reports presented some challenges for the industry as there are a limited number of engineering firms with the expertise and knowledge required to do this type of inspection.
The following five mines were exempted from the order:
- Eskay Creek - TSF does not have any dams.
- Moberly Silica - pond has been filled and there is no longer a dam on site.
- Cassiar-McDame - TSF does not have any dams.
- Lumby Project/Quinto - the mine site is closed and the TSF has been fully reclaimed.
- Mount Polley - The TSF is the subject of three separate investigations and is currently not in use.
The Taurus Gold, Mosquito Creek May Mac and Shasta mines, none of which are in operation, were granted extensions. The extensions were granted because the companies were unable to find a qualified engineering firm that could inspect their TSF before winter conditions set in. Snow cover can prevent engineers from completing the inspections required for a DSI.
Media Contacts:
Jake Jacobs
Media Relations
Ministry of Energy and Mines and Responsible for Core Review
250 952-0628
