Water shortages and lack to safe drinking water will continue to grown as major problems. One billion people access to safe drinking water and 3.4 billion people access to proper sanitation , increasing to access drinking water is the nanotechnology application could play an essential role in the solving this water by introducing effective and cheap waste water treatment techniques .the main aim of the paper is assess the applicability of using nanotechnology in waste treatment in Bangalore, the paper discusses the definition of nanotechnology and green nanotechnology application areas , the paper is defined the using impacts and risks of nanotechnology ,then we defined the case study of Bangalore in using nanotechnology to solve the potential problems to solve the water problems ,the study concluded that although nanotechnology can help to solve the problems ,there is some challenge using nanotechnology ,these challenge include technology ,market challenge and human health risk at Bangalore .waste water treatment is the process of converting waste water that is no longer needed or is no longer suitable for uses into bilge water that can be discharged back into the environment .it is formed by a number of activities including bathing ,washing ,rainwater runoff.