Development of alluvial deposits of minerals is almost always connected with the necessity to include large volumes of surface water in the working cycle of mining enterprises. In the process of open pit mining, process water is enriched with a large amount of suspended material, the content of which in some cases reaches 15-20 g/L. A significant part of these process waters is returned to the river network. Annually within the Magadan region only from washing of metal-bearing placers 1-1,2 billion m 3 of process water enters the river network. ...