Repository - Water Supply and O&M

Abstract: Informally vended water is an important source of water for marginalized people who do  not have access to formal or public sources. In Malawi, hand-tied sachets of water are common but  not regulated, and the quality of the water and hygienic practices during packaging are unclear. We analyzed microbial concentrations in the source water (origin), internal water (packaged) and on the external surface (plastic bag) of sachets from 76 vendors operating in the busy Mwanza crossing into Malawi from Mozambique.

The results indicated that the majority (75%) of the water sources met the WHO guidelines (1 CFU/100 mL) for potable water, while only 38% of the water inside packages met this guideline, indicating a sharp increase in contamination due to packaging and handling practices.

The external surface was highly contaminated and is the point of contact between the consumer’s mouth and the liquid within; furthermore, external contamination was a strong and significant predictor of internal contamination. We advise against strict enforcement that would limit access to this important drinking water source, but recommend hygiene education for vendors that focuses on filling and storage, refrigeration and especially ensuring sanitary coolers from which the bags are sold in order to limit re-contamination during handling.