The technological processes accompanied by significant discharges of mineralized wastewater include continuous blowdown of steam boilers. According to one of the developed technologies blowdown water of steam boilers is used as a heating agent for jet-barbotage vacuum deaerators of a closed heat supply system. In vacuum deaeration plants the high energy potential of blowdown water can be effectively utilized by using it as a working medium for jet ejectors of vacuum deaerators. It is very effective to use blow-off water for fuel oil atomization in steam and steam-mechanical nozzles of boilers. At steam supply of industrial productions, which do not require high purity of process steam, a new technology is applicable, providing complete mixing of blow-off water with steam used in these processes. The developed technologies make it possible to significantly increase the economic efficiency of boiler plant operation as a whole and reduce the amount of mineralized waste water discharges into surface water bodies. A number of technologies for utilization of heat and mass of blowdown water of steam boilers have been successfully introduced into industrial operation at thermal power enterprises in different regions of the country.