Causes and environmental impact of the gold-tailings dam failure at Karamken, the Russian Far East

Abstract

Karamken was one of the most-productive gold-processing plants of the former Soviet Union located in the Magadan Region of the Russian North Far East. This paper discusses the causes, environmental damage and current geo-ecological conditions at the site facility after the accidental breakage of the storage pond in 2009 following industrial activity termination of this state enterprise (1994). The amassed water-saturated tailings from the mineral processing amounted ~280,000 m3, corresponding to a total mass weight of 340,000 tons. The on-site multi-proxy investigations indicate synergic effects of hydrogeology, meteorology, engineering and human factors to have accounted for this major technical and environmental disaster. Piled sedimentary waste masses mobilized by removal of the dam-protective construction components initiated a water leakage into the main dam body and its eventual failure. Activated thixotropic processes of plagioclase clay-enriched sediments in conjunction with heavy machinery works on top of the 27 m-high frontal levee above destabilized permafrost grounds together with lack of the facility maintenance are the main causes for this industrial accident. The outburst of the accumulated deposits spilled large quantities of toxic elements stored in the pulverized saturated tailings, poisoning ground waters and causing severe damage to the local riverine ecosystem and fishery, as well as destruction of the nearby town with human casualties. The identified spillage risk factors could be used to forecast the stability of other similar facilities in the sub-Arctic areas.