Excellent Idea. Might want to consider what happens to the dispensed bottles. Maybe the water is only free if the consumer returns the bottles or the consumer is charged a minimal amount (say Rs 1) to keep the bottle. This way you may be able to recycle them and reduce waste.
It might be a good idea to explore the leasing model used in the solar industry. The company bears the cost of installing the technology, while the consumer pays for the energy used. The added benefit being that the workers have a free toilet to use!