NAIROBI: Using a crutch to bear her weight, 85-year-old Molly Aluoch trudges from her mud-walled room on the outskirts of a sprawling Nairobi slum, shouldering a sack of used plastic to exchange for a shower or a safe toilet. For the 31 years she has lived in Kibera, Kenya’s largest informal settlement, water and sanitation have remained scarce and costly — often controlled by cartels who charge residents prices beyond their means. The Human Needs Project (HNP) seeks to mitigate that.