Cavitation bubble collapse induces a pressure wave, microjet, and temperature in the surrounding media. The intensities of the pressure wave and microjet is severe as per many experimental and numerical investigations. Very few reported the use of shock wave propagation and its implication to disinfect the water. This work mainly focuses on analysing the wastewater for microbial estimation before and after treatment using cavitation produced by ultrasound. For this purpose, we collected the water sample from various sources used for different purposes. Samples collected were divided into six subsamples, of which one was kept as control and remaining were exposed to cavitation for various duration. We observed that the samples exposed to cavitation after 75 minutes showed 99% removal of Total coliform and E. coli from the samples, while the control sample showed significant bacterial colony formation. Hence, our study proposes cavitation as an effective method for physical disinfection of water before releasing it to the freshwater ecosystem.