Background: Drinking water of acceptable quality is supposed to be free from faecal coliform and chemical substances that may be hazardous to human health. Water treatment and safe storage at the household level has been advocated as effective means of ensuring safe drinking water. This study was undertaken to determine the microbiological quality of the drinking water at household level in the squatter settlements in the city of Mwanza, Tanzania.

Methods: A cross-sectional study was conducted between June 2014 and September 2014. A total of 15 randomly selected water sources (tap) and 207 households’ drinking water samples from these sources were studied to ascertain level of water contamination using Membrane Filtration Method. Pre-tested questionnaire was used to collect demographic and other data regarding water treatment and storage. Data were entered, cleaned and analysed using STATA Version 11.

Results: All 15 samples from tap used as water sources were found to be free of indicator organism ( Escherichia coli) while 109 (52.66%) of drinking water samples from 207 households were found to be contaminated with E. coli. All contaminated drinking water samples were from containers with no cover and spigot .

Conclusions: There is a significant level of deterioration of water quality from the source to the drinking cup. Efforts to ensure quality storage methods for drinking water should be addressed at household level.