The concentrations of faecal coliforms were highest in the uplands
and this was attributed to the close proximity of wells to pit
latrines and livestock kraals followed by the gardens where animal
manure was used as soil fertility amendments and lastly the river.
In the uplands, most wells were located within 30 m away from
wells and some of the wells were sited down slope of toilets and/or
animal kraals. This situation therefore favours the movement of
pollutants from the animal pens and toilets to wells. Higher concentrations
of faecal coliforms were detected in the wet season as
these have higher survival rates in wet soils (Jamal et al., 1993). This
suggests that coliforms had a relative higher mobility during the
wet season as there is more water flowing to groundwater during
recharge. Banerjee (2011) reported that transport of total and faecal
coliforms increased during the monsoon period and in sandy soils
and the estimated maximum travel distance of bacteria was 10 m
from pits. In contrast, Chidavaenzi et al. (1997) reported coliforms