Physico-chemical and bacteriological quality of rainwater in Egbema, Imo state, Nigeria

Abstract

Egbema is one of the oil-producing communities in Nigeria and has no access to pipe-borne water, and thus resorts to rainwater as a source of water supply mainly during the rainy season. Physico-chemical and bacteriological quality of rainwater in Egbema was determined with samples harvested directly, from zinc roof, thatched roof and asbestos roof, at different periods of the rainy season namely, Early, peak and late rains. The values of the physico-chemical parameters were on the higher side at the early rains, but moderate (within acceptable range) at the peak and late rains. The values of copper, turbidity, total iron, total hardness and total solids were lowest in rain water harvested directly and highest in that harvested from asbestos roof throughout the rainy period. Generally, the values of the parameters measured in samples from different sources tended to increase in this order: asbestos > thatched roof > zinc roof > direct. The heterotrophic bacterial load was highest at the commencement of rains ranging from 0.45 x 103 cfu/ml to 7.40 x 103 cfu/ml. Also the total coliforms count and fecal coliforms (Escherichia coli) count ranged highest at the early rains between 10 – 22 cfu/100ml and 2 –4 cfu/100ml respectively. The values of heterotrophic bacterial load, total coliforms and fecal coliforms, were within the acceptable range in rainwater samples collected at the peak and late rains. However the bacterial count recorded highest in the samples harvested in the thatched roof and lowest in samples harvested directly direct at the early, peak and late rainy season. This study reveals that rainwater collected at the peak and end of rains from zinc roof and directly if well handled, can be used for drinking and any other domestic purposes.

International Journal of Natural and Applied Sciences Vol. 2 (4) 2006: pp. 372-376