FIELD: agriculture.
SUBSTANCE: method includes feeding into the drain cavity of internal combustion engine exhaust gases. Along with the feeding of the exhaust gases into the drain cavity the spray of aqueous solution of formalin is fed. The drops of the aqueous solution of formalin with the flow of exhaust gases are fed to the inner surface of the drainage pipes and to the slits of the drainage pipes. Formalin blocks the bacterial process of converting the iron compounds into insoluble forms.
EFFECT: iron bacteria are killed, the process of coloring with ochre stops.
