TC Kyrgyzstan: Reduction of Hazards Posed by Uranium Mining Tailings in Mailuu-Suu

Report of the project:

• Kirgisistan - Minderung der Gefahren durch radioaktive Uranbergbau-Altlasten in Mailuu-Suu
• Kyrgyzstan - Reduction of Dangers by Uranium-Mining Waste Sites in Mailuu-Suu

Outline map of Kyrgyzstan Source: CIA World Factbook

Status Quo

In Kyrgyzstan, uranium ore was mined and processed in the region of Mailuu-Suu (100 km NW from Dschalal-Abad) from 1946 to 1968. The resulting waste rock and tailings have been stored together with ore material of inefficient low uranium content in nearby dumps. Altogether, around 3 Million m³ waste material (TACIS 2003) with relatively low radioactive inventory has been deposited in morphologic depressions and covered provisionally.

View at tailing no. 7 Source: BGR

Already under Soviet governance, the environmental impact of the ore mining and milling was foreseen. During the forties, a central water supply was constructed using uncontaminated river water upstream the mining area, thus being out of risk of being polluted by mining activities. The water facility was designed to provide drinking water for 20.000 people but never achieved to reach all residents of Mailuu-Suu. Therefore, several settlements still obtain their drinking water from deep artesian wells, while others are still using simple dug wells in the young gravels of the river valley.

Located in the tectonically highly active region of Mailuu-Suu, the stability of dumps and tailings are endangered by landslides, which may be triggered by recurring earthquakes and seasonal heavy rains. Since several tailings and dumps are located in the immediate vicinity of instable mountain slopes, they may slide into the river. Furthermore, landslides may block and retain the local rivers Mailuu-Say and his tributary Kulmin-Say - such as partly already happened 1992 and 2002 -, leading to a flooding of the nearby dumps and tailings. Both scenarios might be associated with erosion and solution processes of the radioactive inventory. The released radionuclides would not only affect the local water resources, they might also be transported beyond the Uzbek border 25 km downstream of Mailuu-Suu.

Objectives

Subsurface of Mailuu-Suu Source: BGR

Accordingly, the World Bank implemented a 17 Mio $ disaster hazard mitigation project in Mailuu-Suu. In frame of this project, BGR is carrying out the hydrogeological observation with special respect to the planned geotechnical sanitation of the radioactive waste deposits and is building up a long-term groundwater-monitoring in Mailuu-Suu.

The initial stage of the project comprises the definition of the hydrogeological frame and the investigation of the current distribution of contaminants considering the evaluation of physico-chemical and radiological parameters. Subsequently, the risk potential of the different aquifers will be evaluated regarding the planned sanitation actions. The findings represent the basis for conception and construction of a long-term monitoring network.

Another focus is lain upon the realization of workshops and training courses in order to enable the MOE (Kyrgyz Ministry of Emergency Situations) to carry out the long-term operation and maintenance of the groundwater monitoring network. In frame of the capacity building, the technical staff of the ministry will be taught during practical and theoretical workshops in operation and maintenance of the monitoring network. The results and consequences of this study will be fundamental for the formulation of guidelines and recommendations for the local administration and need to be communicated to the concerned population.

Results

Groundwater sampling Source: BGR

The results demonstrate that contaminated seepage water locally already infiltrates from waste deposits into the underlying quaternary river sediments and also flows superficially into the rivers Mailuu-Say and Kulmin-Say. Even though the transport path is still unknown in detail, a dislocation of pollutants downstream is already indicated in both, the river water and the groundwater of the quaternary river sediments.

Little is known about the deeper artesian aquifers and their hydraulic exchange with the shallow quaternary aquifer. The compositions of solutes in the deeper groundwaters indicate a significant hydrothermal influence. It remains unclear whether the deeper aquifers represent a further Uranium source – such as from abandoned mines – and weather they have a significant role in the transport path of radiogenic and other contaminants.

Project partners

• Ministry of Emergency Situations of the Kyrgyz Republic (MoE)
• Center for Radiation Protection and Radioecology, University Hannover (ZSR)
  

Literature:

• JUNG, H.G. & WAGNER, F. (2008): Hydrogeochemical Groundwater Monitoring in Mailuu-Suu, Kyrgyz Republic. - Final report of technical cooperation project "Reduction of Hazards Posed by Uranium Mining Tailings in Mailuu-Suu, Kyrgyz Republic"; 81 pp., Bishkek - Hannover. (PDF, 6 MB)
• TACIS (2003): Final report in frame of EC-TACIS Project No SCREI/No38 Remediation of Uranium Mining and Milling Tailing in Mailuu Suu District Kyrgyzstan. Vandenhove H., Quarch H., Clerc J.J., Lejeune J.M., Sweeck L., Sillen X., Mallants D., Zeevaert Th. (eds.), 2003 Contract Report, R-3721, SCK CEN: 421 pp., Mol, Belgium.
• U.S. Department of Energy / University of California, Lawerence Livermore National Laboratory (2003): Mailuusuu Database.