“TEGHOUT TSF design would be considered unacceptable in terms of its robustness with respect to physical instability compared with international standards. It is considered that there is a high probability of some form of physical instability issue in the future. The TSF design is inadequate, both in environmental and physical stability terms,” says Armenia: Strategic Mineral Sector Sustainability Assessment report prepared by Swedish Geological AB in association with SLR Consultants Ltd, AVAG Solutions Ltd, AUA Center for Responsible Mining AUA Turpanjian Center for Policy Analysis.
According to this report, the upstream raise method is not advisable for seismically active areas as liquefaction of the tailings during seismic events results in a high probability of instability (catastrophic dam wall failure and flow slide).
Teghout TSF was put into operation at the beginning of 2015 by “Teghout” CJSC, a part of “Vallex Company Group”. It collects the tails generated from the development of Teghout copper and molybdenum mine. It was constructed in the gorge of the Kharataots River, where trees were felled down. According to Teghut mine development project, it shall accumulate 173.65 million cum tails, while the report says, the capacity of the tailing dump is 120 million cum.
“In some jurisdictions where seismic hazard is high, the adoption of upstream raises is now prohibited under law (e.g. Chile, Peru). In general, this TSF disposal method is being regarded as being unfavour¬able for medium to high hazard TSFs and is not being accepted by some authorities in countries with a well-developed mineral sector (e.g. Ghana),” the report says. It should be mentioned that Teghout TSF is located in 8-magnitude seismic zone.
Shnogh villagers are especially endangered, “Potential environmental impacts could be broadly estimated, but the population at risk (PAR) and potential for loss of life (LoL) should have been addressed, particularly in relation to the town of Shnogh which lies in the downstream zone of a failure scenario.”
The next risk mentioned in the report is the contamination of environment and water resources with acidic water, “The steep valley side slopes will not be conducive to the placement of a clay liner (it is difficult to place liners on slopes steeper than 1V:2.5H). Hence, seepage will occur through the upper (unlined) valley walls. This seepage could be acidic in the medi¬um to long term and its control is difficult as it can disperse into the natural groundwater system prior to capture and treatment via specifically-designed mitigation measures.
During its short life the leaks out of Teghout tailing dump have already caused much damage to Lori nature, agriculture and water resources. TSF leaks contaminate the Shnogh river, which is already classified as 5-class water – the worst quality water.
15:25 October 04, 2016