Motivated by preventable diarrheal disease in his home state of West Bengal, India while being inspired by automatic water treatment using chlorine in the U.S., Suprio is leading an international team to design an automatic chlorine dispenser that works at community-scale. Zimba works with diverse water sources (rainwater, municipal pipes, well pumps, ponds) and is gravity fed, meaning no electricity or moving parts are required. Lasting over a year in pilot installations with minimal maintenance, Zimba accurately adds the right amount of chlorine without human error or lapses in memory. There have been many iterations, evolving based on feedback from laboratory tests and field tests. Zimba's performance has now been verified by third party reviewers, including from Stanford (http://bit.ly/zimbawash) and PATH (http://bit.ly/zimbapath). The current design has been in development for a few years, and has been undergoing design for local manufacture and assembly in Kolkata, India.