Development of down-flow hanging sponge – slow sand filter system as water purification system: Infection risk reduction in an East Africa rural area

•Many people still drink unpurified water, containing Escherichia coli, in rural areas.•Ingestion of this water causes many potentially deadly diseases such as diarrhea.•We tested a combined water purification system and monitored E. coli concentration.•The DHS-SSF system could reduce the diarrheal infection risk by up to 99.5%.•The DHS-SSF system can provide 30 people with sufficient water (50 L each per day).