DelAgua is working in Rwanda on a 20-year programme to distribute water filters across the country. Distributions are usually from a village hall and will cover a large region where people may have to walk for the best part of a day to be there. Families will carry the filters home to their houses, where community health workers will visit them. Ongoing visits by community health workers track the performance of the programme, and map each installation with GPS coordinates which is collected on a smartphone-based survey. Health education is the cornerstone of making the project a success. Through encouraging the use of improved water treatment, the community health workers enable behaviour change and increase the chances of having a health impact. Rwanda is still recovering from the Ethnic strife and massacres of the mid-1990's, with two thirds of the population living below the poverty line.