The Yanfolila Tailings Storage Facility (TSF) was commissioned in December 2017. The TSF is located in a natural valley which is enclosed by a single, main embankment formed from locally excavated laterites. The embankment has both a natural impermeable clay liner and a poly liner on the upstream wall to prevent seepage and erosion. Each year the main embankment is raised, to accommodate additional tailings deposition, using the downstream method. Prior to each lift an independent assessment of the performance of the TSF is undertaken and this informs the next stage design and scope of works.
| Tailings Facility Name | Yanfolila Tailings Storage Facility. |
|---|---|
| Location | The project is located in the southwest of Mali, bordering onto Guinea. 11ₒ 15’12 N : 8ₒ 25’10 W . |
| Ownership | Société des Mines de Komana (SMK) SA (Subsidiary of Hummingbird Resources plc). |
| Status | Active. |
| Date of initial operation | 9 December 2017. |
| Is the dam currently operated of closed as per the currently approved design | Currently operated per the approved design. |
| Raising method | Downstream lifts. |
| Current maximum height | Embankment 19m, tailings 16.2m |
| Current tailings storage impoundment volume | 4 946 933 m3. |
| Planned tailings storage impoundment volume in 5 years’ time | 4 946 933 m3. |
| Most recent independent expert review | August 2017. |
| Do you have full and complete relevant engineering records including design, construction, operation, maintenance and/or closure | Yes. |
| What is your hazard categorisation of this facility, based on the consequence of failure | Hazardous classification consequence category is High according to both the Canadian Dam Association, Technical Bulletin: Application of Dam Safety Guidelines to Mining Dams and the South African National Standards, SANS 10286: Code of Practice - Mine Residue, 1998. |
| What guideline do you follow for the classification system | South African National Standards, SANS 10286: Code of Practice - Mine Residue, 1998. |
| Has this facility, at any point in its history, failed to be confirmed or certified as stable, or experienced notable stability concerns, as identified by an independent engineer (even if later certified as stable by the same or a different firm) | No. |
| Do have you internal/in-house engineering specialist oversight of this facility? Or do you have external engineering support for this purpose | External engineering support. |
| Has a formal analysis of the downstream impact on communities, ecosystems and critical infrastructure in the event of catastrophic failure been undertaken and to reflect final conditions? If so, when did this assessment take place | Yes, August 2017 (Golder). |
| Is there a) a closure plan in place for this dam and b) does it include long-term monitoring | a) yes b) yes |
| Have you, or do you, plan to assess your tailings facilities against the impact of more regular extreme weather events as a result of climate change, e.g. over the next two years | No. |
| Any other relevant information and supporting documentation. Please state if you have omitted any other exposure to tailings facilities through any joint ventures you may have | No. |