Presentation on theme: "Tailing Dams – A Consultants Perspective"— Presentation transcript:
1Tailing Dams – A Consultants Perspective Harvey McLeod, P.Eng.
2Where doe the Consultant fit in? Mine ManagerOperations and EnvironmentTailings ManagerDam Construction PersonnelConsultant3rd Party ReviewQA/QC of constructionFirst NationsRegulatoryDESIGN OPERATION CLOSURE
3Consultants 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 GuidelinesBe current with the State of Best PracticesApplication of best available technologies to reduce riskSustainable design practices
4Best Available Technologies Mt. Polley PanelDry stack tailingsPits, undergroundReduce waterOtherClosure: Remove ability to store water and create “natural landforms”Robust design (redundancies)Reduce gradients (beaches and no rockfill u/s of coreLiners without drainsNo pipes in dams
6We have Guidelines!! CDA and ICOLD CDA Dam Safety Guidelines CDA Mining Dams BulletinICOLD –Sustainable Design BulletinANCOLD Tailing Dam Design GuidelineMining Association of CanadaTailings ManagementOMS ManualTowards Sustainable MiningAudit GuidelineAPEGBCDam Safety Review
7Engineer of Record? Engineer of Record Relatively new concept Could be the Designer or Mine PersonnelDifficult for tailings dams that can be operated over 40+ yrsAuthority is difficult to make commensurate with the responsibility (e.g. operations)Designer of RecordClear distinctionCan also be engineer of record
8Consultants Responsibilities Dam Safety InspectionVisual checkInstrumentation checkWater management checkRecommendationsDam Safety ReviewAPEGBC GuidelineAudit type;Comprehensive; orDetail Design and Multidisciplinary
9APEGBC 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 data2. Reviewed the environmental objectives for the materials stored in the impoundment and related design requirements3. Understood the current classification for the Dam, including performance expectations4. Undertaken an initial facility review5. Reviewed and assessed the dam safety management obligations and procedures6. Inspected the condition of the Dam, impoundment area and relevant areas upstream and downstream of the facility7. Interviewed operations and maintenance personnel8 Interviewed Engineer of Record9. Reviewed available maintenance and operating records, the Operations, Maintenance and Surveillance (OMS) Manual and the Emergency Preparedness Plan10. Confirmed proper functioning of mine waste and water management systems and environmental control systems11. After the above, reassess the consequence classification, including the identification of required dam safety criteria12. Carried out a dam safety analysis based on the classification in Item 1113. Evaluated facility performance and conformance with design basis and operating criteria14. Identified, characterized and determined the magnitude of deficiencies in the safe operation of the Dam and non- conformances in the dam safety management system15. Recommended and prioritized actions to be taken in relation to deficiencies and non-conformances16. Prepared a DSR report for submittal to the Regulatory Authority by the Owner and reviewed the report with the owner
10APEGBC Dam Safety Review Assurance Statement Based on my Dam Safety Review, the Dam classification is:□ Appropriate□ Should be reviewed or amendedI undertook the following type of Dam Safety Review: □ Audit□ Comprehensive□ Detailed design-based multi-disciplinary□ Comprehensive, detailed design and performanceI 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.
11Consultants Responsibilities Third Party ReviewIndependent of the ConsultantReports to Senior Management or other StakeholdersPresents an “opinion” on the Tailings Facility Design and operations
12Challenges and Opportunities PeopleTransfer of knowledgeTeach “critical thinking” ???? - Belief in “models”Shortage of qualified Third Party ReviewersEngineer’s responsibilities commensurate with authorityNo. of Dams and Long Term LiabilityClosure land use to be consistent with FN valuesNeed to move to landforms on closure
13Challenges and Opportunities ClientsSelection on cost, not riskConsultant has little control over operations and may have limited control in constructionTechnical capacity limitations and clear role definitionsRegulatoryTechnical capacityEnforcementFirst NationsTrustDesign for closureCommunication and transfer of knowledge