Qualitative Assessment of the Effect of Thunderstorm on Rainwater Harvesting from Rooftop Catchments at Oke-Lantoro Community in Abeokuta, Southwest Nigeria

Abstract

Intensive temporal sampling of Rainwater Harvesting System from three rooftops runoff from a catchment at Okelantoro Community in Abeokuta, Southwest Nigeria was carried out to assess the effect of thunderstorm on the water quality. Assessment was undertaken according to different physical and chemical parameters including biological oxygen demand (BOD), Dissolved oxygen (DO), electric conductivity (EC), Alkalinity, Total hardness (TH) and some major cations and anions. Results showed strong dilution effects in the variation in harvested rainwater quality with thunderstorm and rainstorm s, however, the rainwater harvested under thunder storm had less pollution as compared to water harvested from rain storm. The asbestos roofing sheet water sample gave higher calcium and magnesium content which reflects in the total hardness value. Sample from the aluminum roofing sheet gave the best result but it was also affected by the influence of atmospheric dust particles associated with strong winds that is associated with tropical storms. Considering the results of the physico-chemical tests, irrespective of storm, the harvested water samples could be put to other domestic uses, as they cannot be consumed directly