Geochemistry of the Kayrakum Reservoir on Central Asia’s Syr Darya

The Kayrakum Reservoir is situated along the Syr Darya (Syr River) in Central Asia, downstream from extensive mining and industrial operations. This document includes a description of these operations. The reservoir has been the recipient of large amounts of sediments since it was put into operation in 1950. As a preliminary study, 50 sediment and 23 soil samples were collected close to the shores of this reservoir and analyzed using energy dispersive X-ray fluorescence. This technique has a sensitivity of 2 ppm for elements above K in the Periodic Table. The results revealed no dangerously high levels of heavy metals in the soils and sediments. However, given the history of mining and fabrication activities in the Syr Darya basin and given the importance of long term water quality below the reservoir, a more thorough analysis of reservoir sediments, especially those offshore, towards the middle of the reservoir and including the radiometric determination of uranium and thorium daughter products is warranted.