The paper presents the sonic treatment effect on the microbiological indicators of the raw water, namely total germ number, Streptococci number, total coli forms and fecal coli forms. Also, the paper comprises the sonic installation which includes the vertical reactor and the air-jet ultrasound generator. The results allow the development of a new raw water treatment technology that will eliminate the actually two-stage treatment - filtration and chlorination, for the drinking water plants.