Monsoon is the unique phenomenon that brings lot of rain to the terrain and supports the life to a large extent. During this rainy season, the water quality degrades due to the addition of physical, chemical and microbial contaminants. In this present work, we have done a study on the bacteriological contamination level of the water, which we have collected from different sources during this period. It is obvious that during monsoon period the outbreaks of the diseases will be very high due to the high level of microbial contamination and drinking the water without proper treatment. Bacterial contamination levels, water borne diseases, general instructions to avoid water borne diseases are discussed in this study. Copyright@ EM International. © 2011 Elsevier B.V., All rights reserved.