1. Tailings Dam Safety And Implementation Of Safety Guidelines By A Tailings Dam Operator
This presentation presents an operators view on implementing a Dam Safety program for a tailings facility. The presentation is does not present the dam safety program for a particular mine, rather it presents some of the concepts and issues that have been found most important when carrying out dam safety programs at mine sites.

2. Why are Dam Safety Programs Important?
Los Frailes Spain
All people involved in mines with tailings facilities must understand the importance of the dam safety program. The consequences of not identifying deteriorating conditions or performance and correcting these conditions can lead to dam failures, deaths in the downstream communities and environmental destruction. Training is therefore one of the key aspects of a dam safety program. Everyone involved must understand the importance of the activities. People’s lives are at stake.
Merriespruit South Africa

3. Dam Safety Program Implementation
Guidelines provide templates and flow sheets for dam safety programs
Operator must translate these into activities that can be carried out at the tailings management site to create an effective dam safety program
There are many guidelines available for developing dam safety programs. Examples are the Canadian Dam Association Dam Safety Guidelines (2007), the FEMA Federal Guidelines for Dam Safety (2004), the Queensland Dam Safety Management Guidelines (2002), ICOLD Tailings Dam Safety Guidelines, Bulletin 74 (1989). All these guidelines are similar and provide a context or framework for the operator to develop an effective dam safety program. All of the guidelines provide a complete framework for developing a dam safety program, and it is best to work with one guideline rather than trying to mix and match pieces from various guidelines.

4. Dam Safety Program Development
A good Dam Safety Program requires collaboration of a number of groups.
Operators, designers and regulators must all provide input to the dam safety program
Risk based approach can simplify the dam safety program:
Consider consequences of potential failure modes
Focus program on key failure modes
Program must consider the “tailings management system” – not just the dam
Program must be set up understanding that the system and risks will change over the mine life – recognize the changing conditions and changing risk
An effective dam safety program must include input from the operator, the facility designer and from the responsible regulator. Often the input from the regulator comes through the dam safety guidelines that are selected or mandated for use on the project.
The tailings facility designer(s) and the operator must collaborate on developing the dam safety program. The designer has the best understanding of the expected performance of the facility and the critical safety issues. The designer must identify performance issues, the expected range of performance and the appropriate response to changes in performance. For example, a rising phreatic surface in a dam abutment may indicate increasing seepage into the abutment and deteriorating performance, or it may be a response to increased rainfall. Site personnel can identify the changing condition, but need the designer to provide a context for evaluating the change.
The operator has an overall production and management system for the mine, and the dam safety program must fit within this management system. Safety programs that conflict with other management systems used on a site are rarely carried out properly, and safety can be compromised.
Guidelines for preparing Operation, Maintenance and Surveillance Manuals for tailings facilities are available, for example the Mining Association of Canada Guidelines for Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities.

5. Roles and Responsibilities
Roles and responsibilities must be clearly defined
The designer and the regulator do not control the operation of the facility and are not involved in the day to day operation
Therefore, everyone must understand that the owner/operator is ultimately responsible for the safe operation of the facility
The Mine Manager must accept this responsibility and mandate that the dam safety program will be followed without exception.
Dam safety guidelines set out roles and responsibilities for dam safety. These include the roles of regulators, the designers, the contractors, the mining company and its personnel. Each person or group has a role, but the Mine/General Manager is the key to successful implementation of a dam safety program at a mine. A strong mandate from the Mine Manager sets the importance and direction of a dam safety program. Dam safety concerns must rank at least equally with production concerns.

6. Training Best to have designer involved in training
Present key aspects of the design, critical issues. Helps to focus site staff on the key issues
Designer to have at least annual review of performance – field inspection and review of documentation
All personnel that will be in vicinity of facility should be trained to identify conditions that could lead to failure
All personnel should know how to report a potential problem
Ongoing training is a requirement of a dam safety program. The training program should include everyone that will be involved with the tailings and water management systems. A general training program should be given to personnel who are infrequently involved with the system. A detailed training program should be developed for the people involved with the system on a day-to-day basis. This should include all levels of people, from the drivers and maintenance workers to the senior technical staff. Everyone needs to know the type of conditions that need immediate attention, and how to report these conditions.
A training workshop that includes the facility designer can be very effective. The designer can present the facility design, the assumptions that were made, the expected performance and the most critical issues for the facility. For operating facilities, the operators and workers can provide feedback to the designer on operating problems and issues that need to be addressed in design revisions or changes to the surveillance program. Regulators can also be involved to present the regulatory framework in which the mine operates, and also to develop a better understanding of the facility design and expected performance.

7. Inspections
Frequency of inspections and monitoring data collection depends on the rate of system changes
Routine inspections on a weekly or monthly basis
Frequency may change depending on the season
Daily to weekly during wet season or during snow melt
Monthly during dry season
By site personnel
Engineering inspections on a semi-annual to annual basis
By designer
Special inspections after significant events
By designer and site personnel following earthquakes and floods
A dam safety review every 5 to 10 years
By independent engineer (not the designer)
Inspections are critical to effective implementation of a dam safety program. The frequency of inspection and the items for inspection will be set out in the Operation, Maintenance and Surveillance Manual. Inspections are most effective if they are carried out by the same group of staff over a period of time. Digital photography also assists in tracking the changes in a structure, if the photographs are properly annotated and filed for future reference.

8. Inspections Check lists for inspections Inspection forms
Don’t miss key information
Simplifies inspections – inspector can focus on the observations
Inspection forms
Information is presented in a consistent format, changes in system performance are more easily identified.
Completing the checklist does not mean the inspection is complete
Evaluation of the information collected is the important step – how is the performance of the facility changing and are these changes consistent with the expected performance
Data collection and inspections can be simplified by the use of checklists. This allows the inspector to focus on the observations rather than trying to remember the items to be inspected. Checklists and forms present the data in a consistent format, and this simplifies interpretation of the results. Graphs should use the same scale from one inspection to the next.
It is important that all inspection and data collection activities be completed, but from a safety perspective, putting a check mark in the box on the check list does nothing to maintain the safety of a dam. The important activity is the compilation the observations and data and assessment of the actual performance relative to expected performance.

9. Typical Inspection Forms
Templates for inspection forms should be modified to suit the project specific conditions. The use of checklists and forms facilitates the inspection process. The inspector can focus on the important aspects of the dam and recording of the information.
However, as already mentioned, the inspection is not complete when the form is filled out. The inspector must review the information, identify any problems that could trigger further inspections or actions, report the conditions as set out in the OMS manual, and then file the information for future reference.

10. Inspection Forms to Include Photographs
July 2005
June 2006
Digital photographs provide an easy way to catalogue the condition of a dam and to identify changes that occur slowly over time. To be most useful, photographs should be taken from the same location each time, annotated with the data and any pertinent observations on condition or weather and stored with the other dam performance information.
PHOTOGRAPH North Dam 1: View to the east along the downstream toe of the North Dam near the west abutment. Toe and face are in good condition. Small puddles of water in natural topographic depressions. Condition in 2006, including the size and location of water downstream of the dam, is similar to that observed in 2005 as shown by comparison of the photographs.

11. Graphical Presentation of Monitoring Data Aids Interpretation
Graphical presentation of monitoring data aids in the interpretation of performance. Data can also be grouped to assist in interpretation. For example, this graph shows the pore pressures that have been measured at various points in the abutment of a dam from the start of filling the pond. Also shown on the graph are the daily rainfall information and the water pond elevation, which affect the water pressures in the abutment. The seasonal effect of the rainfall is evident.

12. Key Learnings Training
Everyone involved with the tailings and water management facility should be trained to identify and report conditions that could lead to failure.
Training workshops involving the designer, the operators and the regulators are very effective. The operators need to understand what is important for dam safety, and why it is important.

13. Key Learnings Inspections and Data Collection
Continuity of personnel important
Human eye can identify small or subtle changes in a structure
Filling out the inspection form is only the first step. The inspection is not complete until the interpretation of performance is complete.
There is a learning curve to understanding the performance of a dam

14. Key Learnings Review and analysis Responsibility
Continuity of personnel important
There is a learning curve to understanding the performance of a dam
Important to have independent review and verification of the dam safety periodically
Responsibility
The Mine or General Manager has the largest influence on successful implementation of a dam safety program. Dam safety must rank equally with production.

15. General Comments
Visit mines with similar types of tailings management systems
Discuss the dam safety program
Discuss the good and bad parts of your program so that both can learn
Review case histories of dam failures
Modern dam failures are well documented and the root cause of the failure is often identified in the investigation reports.
Obtain current copies of dam safety guidelines
Guidelines are updated as the understanding of the mechanisms of dam failures improves
With modern communication systems, news of a tailings facility failure is known worldwide immediately and will affect the international mining community

16. Our goal: our tailings dams become an integral part of the environment post-closure

17. Feedback on the UNECE guidelines
This document is a good starting point but to be useful to industry (dam operators) guidelines need to be specific
There are a number of useful groups of documents already in use – such as the CDA Dam Safety Guidelines combined with the Mining Association of Canada guidelines for designing a tailings facility and for preparing operation, maintenance and surveillance manuals.
It could be helpful to collaborate with some other agencies who have already developed regulations and guidelines for the safe operation of TMF’s such as ICOLD, CDA, or MAC.
The principles are now established and the document needs detail. Actions are mandated but the specific details and information required to carry out the activities, frequencies of activities and design criteria selection parameters are not yet detailed.
There are a number of agencies that have already constructed useful regulations and guidelines (such as the Canadian Dam Associate and Mining Associated of Canada) and it would be benifical to learn from these agencies and the guidelines that have been developed.

18. An Operators perspective
Operators require information on how to carry out the activities, frequencies of activities, selection of design criteria
Some areas to be developed to make these guidelines relevant to operators are
how to assess risk
What factors of safety to use in construction
Details on preparation of operations manuals
Parameters such as return periods for inflow design floods
Seismic event parameters
Recommendations on planning tools to be used – such as water management modelling tools
The document provides some guidelines as to what needs to be assessed but it does not provide specifics of what standards must be achieved, for example the annex includes this clause:
"(b) tailing dam - following parameters need to be assessed
accurately:
- the stability of the dam
- the stability of the tailing material
- erosion to the dam
- slope sliding"
But there is no context for the stability assessment - what factor of safety should be used as the minimum? How will the factor of safety be selected? Will the factor of safety be selected based on the risk of the structure, or will it be the same for all structures?

19. Deno Gold Mining Company, Kapan, Armenia
Kapan - Located in SW Armenia
Historical mining town
Approx 250 years of mining
300km from Yerevan
Two main deposits with numerous smaller deposits in the mines vicinity

20. DGMC - a little history 2004 KOMPE mine bankrupted
Operated as DGMC
Dec Starter loan by EBRD initiated upgrade existing equipment and environmental programmes
WAI work with site staff to write EAP’s and proposed monitoring programmes
Construction of Geghanush TMF
Sept Dundee bought 80% company, began corporate responsibility programme
April Begun environmental baseline study
Sept fulltime environmental staff and local consultants, ~ international consultants
End Commissioning of Geghanush

21. When Dundee came to Kapan they found a dam that was not built in the western standard. The difference that between the western approach and the Eastern block country approach is a mainly a different perception of risk. We take a risk assessment approach to design construction and operation of a TMF, where the eastern focus is more focussed on the norms. One of the big differences between western design and eastern design is having decant structures (piccolos) run through the structure..
Good designs (even with picollos running through the structure) and more importantly construction control is important. The design can be perfect but short cuts or poor workmanship can undermine good design.
We had a dam in construction that we felt we needed international review of to the design to ensure long term safety.

22. Artsvanik Dam
Small Tails Dam perched on very large Kadjeran TMF dam structure
Designed in 2003 by Armenian design institute
Capacity 1.1 Million m3 Maximum dam height 20m
Regular inspections from RA inspectors
Regular inspections from International Tailings Dam Engineer
Continuous monitoring by site staff
Dam movement (triangulation surveys)
Water quality and level
Peizometer water level checked daily
Rainfall data collected and weather station in use
Drilling crest of wall and analysis undertaken of materials
Procedures in place to stop production in heavy rainfall or if water level rises
Operate with lowest possible phreatic water level to maximise capacity during rainfall events.

23. Geghanush Dam
New dam over existing historic dam – capacity 11.0 million m3
Construction included front and rear dam walls, completion of diversion tunnel for river, gravity decant structures
Plans and design were review by international tailings dam engineer and modified to include recommendations including finger drains
Recycling water to process plant should decrease discharge significantly
Same monitoring programme as Artsvanik to be implemented
Discharge water system is gravity decanted however backup submersible pumps will be available for extreme rainfall events

24. Thank You