Method is intended for reduction of environment in interior part of the earth after completion of working out blocks of ore deposit by underground leaching of metals. Operating holes through which leaching solution was given and soluted metal was extracted, are used in reduction interior part of the earth.

After completion of deposits’(blocks) use by underground leaching in interior part of the earth, sulphate solutions with chemical elements in concentrations dissolved in them of no industrial significance, but exceeding maximum permissible concentrations (MPC) are remained. Residual solutions are of no use for economic utilization and represent threat of pollution of underground waters and beyond the block of leaching. Process of clearing is fulfilled by pumping accumulating culture of microorganisms with the organic nutrition for them through existing net of holes. For more rapid penetration of bacteria in purification zone accumulating culture is pulled towards pumping hole with a pump.

Purificated underground waters may be used in economic needs.

Method has been tested in a number of industrial installations and is covered by patent.