Tailing Dams – A Consultants Perspective Harvey McLeod, P.Eng.

Where doe the Consultant fit in? Mine Manager Operations and Environment Tailings Manager Dam Construction Personnel Consultant 3rd Party Review QA/QC of construction First Nations Regulatory DESIGN OPERATION CLOSURE

Consultants Professional Responsibility Protection of health and safety of the public Protection of the Environment Meet all Provincial and Federal regulations and guidelines Meet Professional Practice Guidelines Be current with the State of Best Practices Application of best available technologies to reduce risk Sustainable design practices

Best Available Technologies Mt. Polley Panel Dry stack tailings Pits, underground Reduce water Other Closure: Remove ability to store water and create “natural landforms” Robust design (redundancies) Reduce gradients (beaches and no rockfill u/s of core Liners without drains No pipes in dams

Tailings Risk Reduction

We have Guidelines!! CDA and ICOLD CDA Dam Safety Guidelines CDA Mining Dams Bulletin ICOLD –Sustainable Design Bulletin ANCOLD Tailing Dam Design Guideline Mining Association of Canada Tailings Management OMS Manual Towards Sustainable Mining Audit Guideline APEGBC Dam Safety Review

Engineer of Record? Engineer of Record Relatively new concept Could be the Designer or Mine Personnel Difficult for tailings dams that can be operated over 40+ yrs Authority is difficult to make commensurate with the responsibility (e.g. operations) Designer of Record Clear distinction Can also be engineer of record

Consultants Responsibilities Dam Safety Inspection Visual check Instrumentation check Water management check Recommendations Dam Safety Review APEGBC Guideline Audit type; Comprehensive; or Detail Design and Multidisciplinary

APEGBC Dam Safety Review Assurance Statement  I have signed, sealed and dated the attached dam safety review report on the Dam in accordance with the APEGBC Guidelines. That report must be read in conjunction with this Statement. In preparing that report I have:   Check to the left of applicable items (see Guideline Section 3.2):   1. Collected and reviewed available and relevant background information, documentation and data 2. Reviewed the environmental objectives for the materials stored in the impoundment and related design requirements 3. Understood the current classification for the Dam, including performance expectations 4. Undertaken an initial facility review 5. Reviewed and assessed the dam safety management obligations and procedures 6. Inspected the condition of the Dam, impoundment area and relevant areas upstream and downstream of the facility 7. Interviewed operations and maintenance personnel 8 Interviewed Engineer of Record 9. Reviewed available maintenance and operating records, the Operations, Maintenance and Surveillance (OMS) Manual and the Emergency Preparedness Plan 10. Confirmed proper functioning of mine waste and water management systems and environmental control systems 11. After the above, reassess the consequence classification, including the identification of required dam safety criteria 12. Carried out a dam safety analysis based on the classification in Item 11 13. Evaluated facility performance and conformance with design basis and operating criteria 14. Identified, characterized and determined the magnitude of deficiencies in the safe operation of the Dam and non- conformances in the dam safety management system 15. Recommended and prioritized actions to be taken in relation to deficiencies and non-conformances 16. Prepared a DSR report for submittal to the Regulatory Authority by the Owner and reviewed the report with the owner

APEGBC Dam Safety Review Assurance Statement Based on my Dam Safety Review, the Dam classification is: □ Appropriate □ Should be reviewed or amended   I undertook the following type of Dam Safety Review:  □ Audit □ Comprehensive □ Detailed design-based multi-disciplinary □ Comprehensive, detailed design and performance I hereby give my assurance that, based on the attached Dam Safety Review report, at this point in time:  □ The Dam is reasonably safe in that the dam safety review did not reveal any unsafe or unacceptable conditions in relation to the design, construction, maintenance and operation of the Dam as set out in the attached dam safety review report. □ The Dam is reasonably safe but the dam safety review did reveal non-conformances with the regulatory requirements with respect to the dam safety management systems as set out in section(s) ____ of the attached dam safety review report. □ The Dam is reasonably safe but the dam safety review did reveal deficiencies and non-conformances with the regulatory requirements with respect to the dam safety management systems as set out in section(s) ____ of the attached dam safety review report. □ The Dam is not safe in that the dam safety review did reveal deficiencies and/or non-conformances with the regulatory requirements which require urgent action as set out in section(s) ____ of the attached dam safety review report.

Consultants Responsibilities Third Party Review Independent of the Consultant Reports to Senior Management or other Stakeholders Presents an “opinion” on the Tailings Facility Design and operations

Challenges and Opportunities People Transfer of knowledge Teach “critical thinking” ???? - Belief in “models” Shortage of qualified Third Party Reviewers Engineer’s responsibilities commensurate with authority No. of Dams and Long Term Liability Closure land use to be consistent with FN values Need to move to landforms on closure

Challenges and Opportunities Clients Selection on cost, not risk Consultant has little control over operations and may have limited control in construction Technical capacity limitations and clear role definitions Regulatory Technical capacity Enforcement First Nations Trust Design for closure Communication and transfer of knowledge