Environmental Issues and Proposed Assessment of Feasibility of Remediation of the Legacy Sites of Mining and Milling in the Area of Sumsar-Shekaftar in Kyrgyzstan

Abstract

From 1946 to 1978, extensive mining of U and Pb–Zn ores went on in the northern edges of the Fergana valley on the foothills of the Tien Shan Mountain Range. The mining and milling activities left behind large volumes of wastes in the lower section of the Sumsar-Say, which is a cross boundary river. The mill tailings of the Pb–Zn milling in Sumsar and the low-grade U ore heaps in Shekaftar need an urgent remedial action because the legacy sites became chronic sources of toxic and radioactive contaminants for the Sumsar-Say River. In the Sumsar Say valley, the river acts as a powerful transport agent of the released contaminants carrying them to the places of potential impact, which are the down-stream settlements in Kyrgyzstan and Uzbekistan. For the settlements along the river, Sumsar-Say is the main source of water and the population uses it indiscriminately. Thus, the exposure of the local population to the contaminants is via a multitude of pathways. The legacy sites requiring remediation most are (a) the tailings facility #1 in Sumsar that is chronically loosing tailings into the Sumsar-Say River and (b) the low-grade U ore heaps in Shekaftar, which are within the domain of the river, particularly ore heap no. 5, which is directly located in the river. The paper discusses possibilities of remediation and, regarding the risk and feasibility assessment, arrives at the conclusion that sustainability of remediation would be best achieved by taking out the sources of contaminants from the reach of the Sumsar Say River.