Abstract
The main objective of this study is to assess the effect of rainfall and surface runoff in contamination of rainwater harvesting, it is collected in underground reservoirs in Jefara District of Libya. The place is used to activate pasture. The water is collected for domestic use and drinking purposes. Samples from (14) reservoirs were collected during winter season and analyzed for the presence of total coliform and fecal coliform. In all samples, total coliforms and fecal coliform were found. A simple unit (reactor) was designed for disinfecting water from total coliform and fecal coliform by heating at a different temperature under continuous fed water. In conclusion non-point source pollution that carried by rainfall and runoff has a significant effect on the presence of bacteria in rainwater harvesting. In addition, effective disinfection of water from total coliform and fecal coliform was achieved at temperature of 50 oC or above. Finally, the unit (reactor) was run at Hydraulic Retention Time (HRT) 2.4 h.