Acidification of rain water in urban cities is playing major environmental issues. Acid rain is generally caused by the formation of sulphuric acid and nitric acid. These sulphur and nitrogen emission are resulted from different sources like industries, vehicles etc. Rain water is a major source for ground water recharge in urban and rural India, Government of India has already provided water policies in 1987 and 2002 for conservation of water with different technology of harvesting. Roof top rain water harvesting is a good practice to collect rain water and inject it directly in the ground without much contamination. Ministry of Environment and Forest (MoEF) suggested different design and material selection for rain water harvesting pits to remove the suspended particles and other impurities, however no provision of controlling the pH is provided for the acidic rain water. Hence the present study proposes modification in the existing rain water harvesting pit to neutralize the acidic pH from rain water.