Relationship between water quality status and resuspended sediment fecal bacteriological quality in Nakivubo wetland

Abstract

The reuse of domestic and industrial wastewater in urban settings of the developing world may harm the health of people through direct contact or via drinking water. Nakivubo wetland whose water is used by both domestic and industrial purposes is believed to be contaminated as a result of the wetland reducing in size leading to reduced filtration potential hence posing a risk of water-borne infections to the people using the water in the wetland and that of Lake Victoria where the wetland drains.

Field and laboratory studies were carried out to assess the relationship between physical water quality status and resuspended sediment (disturbed) fecal bacteria in the wetland. Sample assessments were made on the physical water quality parameters which were observed to be within the NEMA standards. Samples of Fecal Coliform counts and E.coli counts for both undisturbed (overlaying water column) and disturbed (resuspended sediment) in 3 sites along the wetland showed that the resuspended sediment had significantly higher Fecal Coliform counts at (F = 7.842; P = 0.006) than the samples taken from the overlying water column and no significant effect of disturbance levels in E. coli counts at (F = 0.974.; P = 0.343).

Multiple regression analyses were performed to examine if the physical water quality parameters could be used to predict E. coli or Fecal Coliform counts in Nakivubo wetland and it showed that there were no significant relationships between any of the factors. The presence of fecal bacteria in sediment is not fully known however the study concluded that by monitoring bacteria in sediment as well as the overlying water column, a more accurate depiction of water quality could be completed hence would save concerned authorities and municipalities time, money, and effort when creating an effective management program for the wetland.