Abstract
The study assessed the impact of the water supply intervention on the health-related microbiological water quality of source and stored water. The study area was a rural community with limited access to safe drinking water and sanitation systems for use. Previously, participating households had to collect water from remote sources (sub-villages near the river and irrigation canals), store water in various types of containers before use and under certain conditions in the domestic environment that may impact negatively on the water quality. These sub-villages were referred to as the Intervention group. The Reference group, were households from the same village (sub-villages away from the river) and for many years have collected and used water from communal taps. The water from the tap was pumped from a groundwater source of a better microbiological quality compared to the Intervention groups’ surface water.
Communal standpipes that were installed several years ago were operationalised (water supply intervention) in the Intervention group at the time of the study and provided the opportunity to compare the various water sources and their impact on the health-related microbiological water quality of container-stored water.
There were significant differences in the quality of various water sources used by the Intervention and Reference groups. The level of contamination was found to be higher in the Intervention group surface waters than in the Reference group tap water (groundwater source). Counts of total coliforms and E. coli were much higher in the Intervention group water sources than the Reference group, indicating that surface water was exposed to more pollution in the environment than the protected groundwater supplying taps.
There were also significant differences in the water quality of source and container-stored waters used by both Intervention and Reference groups. The numbers of indicator organisms were significantly lower in the Intervention group container-stored river water than in the river source water, suggesting bacterial die-off in stored water. For the Reference group, higher counts of total coliforms and E. coli were found once tap water was sourced and stored in containers at home. The level of these indicators in the Reference group stored water supported the statement that water of good quality at the source often becomes
contaminated during storage at home but in case of the Intervention group river water, the storage process brought about improvements in water quality. Container water quality of the Intervention group was assessed “before” and “after” the water supply intervention. A significant decrease was found in the indicator organism numbers (total coliforms and E. coli) “after” the intervention, showing a strong association between the use of an improved water supply and a good water quality. The results have also shown that the Reference group container-stored tap water had lower indicator organism numbers than the Intervention group container-stored river water before the intervention.
After the Intervention group tap water was operationalised, its container-stored waters were compared to that of the Reference group (both groups now on tap water), and surprisingly there were significantly higher numbers of indicators in the Reference group stored water, suggesting poor domestic hygiene practices. No significant differences were expected because the same supply was used by both groups.
Twenty eight households were randomly selected to assess the sustainability of the water supply intervention after one year of using tap water by the people of Folovhodwe, especially those from the Intervention group. There was a significant increase in the indicator organism numbers in container-stored water after one year of using tap water. Higher levels of indicator organisms (one year later) were probably associated with inadequate water handling practices at home, since the borehole groundwater after one year had zero indicator organisms (total coliforms and E. coli) indicating good water quality at the source.
The health-related microbiological quality (at the source and in the containers) did not comply with the proposed safety limits in various water quality guidelines. A negative outcome in both groups was that E. coli was still higher than the WHO risk limit for water intended for drinking at the source and in storage containers suggesting continued faecal pollution of the water. Judging by the overall results, it is evident that the water supply intervention played a role in reducing the numbers of indicator organisms, although still above the guideline limits. It also appears that water supply interventions alone are not sufficient to improve and maintain water quality especially at the point of consumption; therefore hygiene practices around stored water at home need to be improved in order to achieve maximum health benefits.
Prof. P. Jagals
Ms. B. Genthe