Sustainable nanotechnology is important for providing contaminant-free water to humanity. In this talk, Dr. Pradeep will present the compelling need for providing access to clean water through nanotechnology-enabled solutions and the large disparities in ensuring their implementation. Dr. Pradeep will present the discovery of affordable and sustainable nanomaterials to selectively scavenge arsenate and arsenite ions (and others) in water to bring their concentrations below the drinking water limits and its development into a technology. The solution, popularly called AMRIT (meaning elixir in Sanskrit), is now delivering 80 million litres of arsenic-, iron- and uranium-free water, conforming to international standards every day to 1.3 million people at the cost of 2.1 paise (US$0.00026) per litre, lowest in the world.