In 1993, Bangladesh found its main source of fresh water was contaminated with natural arsenic, resulting in a public health threat impacting millions of people. In cooperation with the World Bank, the IAEA used isotope hydrology techniques to help the country to find safe drinking water. By using nuclear techniques, Bangladesh was able to demonstrate that isotope hydrology could effectively and affordably help to locate identify safe sources of water. This film demonstrates some of the effects of arsenic poisoning in these villages and its successful resolution.