Water is a substance that has an important role in life all living creatures in this world. Humans need a lot of water to meet daily needs. Water can be obtained and used for fulfill needs such as drinking, bathing, washing, cooking, recreation and other environmental activities. Microbiological water safety is important to prevent the spread of waterborne disease. In this study, we develop the portable, simple and cheap method and tools for enumerating bacteria against the standard method Total Plate Count (TPC). Preliminary study with 28 samples of miniaturizes Most Probable Number (mini MPN) result compared to TPC showed sensitivity 84% and specificity 100% with Cohen’s Kappa 0.854, it means almost perfect agreement. Sample which contained bacteria, was then isolated onto MacConkey agar plates. Bacterial isolates were identified and antimicrobial susceptibility tested using automated Vitek 2 Compact. The result showed 4/7 was Acinetobacter baumannii, 1/7 was A. baumannii calcoaceticus complex, 2/7 was Moraxella group. None of the isolates were resistant to relevan antibiotic. Virulence test in vivo using Omphisa fuscidentalis larvae showed none of the isolates were highly virulence (with 70% survival maximum) compared to clinical isolate K. pneumoniae with 0% survival after 24 hours injection.