The Radikal plant was one of ten huge chemical plants in the USSR. Between 1954 and 1996 it produced chlorine and caustic soda by electrolysis with a mercury-pool cathode. A great deal of mercury was deposited in the chlorine production buildings. The most massive mercury contamination was observed in the tank room floor and in the soil under the factory. Since 2003, cleaning and demercurization works have been taking place. The government plan is to remove about 130,000 tonnes of mercury waste, 120,000 tonnes of which will be buried without reprocessing (low concentration of mercury), while 10,000 tonnes will be exposed to thermal demercurization (high concentration of mercury).