- Water in Kibera slums of Nairobi, Kenya is scarce, costly, and often contaminated, with residents spending significant time and money searching for water. - While mobile phone access is widespread, consistent access to clean water is lacking. - The M-Maji project aims to use ubiquitous mobile phones to improve access to clean water by connecting water buyers with verified vendors through a USSD-based platform. A pilot program will test the impact on water prices, search times, and clean water uptake.