Towards Sustainable Water Quality: Management of Rainwater Harvesting Cisterns in Southern Palestine

Environmental management of rainwater harvesting in southern Palestine is required to reduce the continuously increasing demand for fresh water from limited water aquifers and to reduce the adverse health impact on the people drinking harvested rainwater. This continuously increasing demand for fresh water requires the enhancement of environmental conditions surrounding the cistern owners’ awareness to tackle the mismanagement that contributed to rainwater contamination. In this study, 100 cisterns were sampled and tested for physiochemical and microbiological parameters. Most of the tested physiochemical parameters were within the acceptable limits of WHO and Palestinian standards except turbidity, calcium and magnesium where 24%, 47% and 32% of the samples were non-conforming, respectively. The pH values of the collected rainwater ranged from 7.32 to 8.97 with a mean value of 8.16. The nitrate analysis results range from 1.5 to 7.0 mg/L, with a mean value of 4.2 mg/L. High percentage of cisterns were found to be contaminated with total Coliforms (TC) and faecal Coliforms (FC) with percentages of 95% and 57%, respectively, rendering the cistern water unacceptable for drinking purposes. 78% of samples had a severe degree of contamination for which water needs flocculation, sedimentation then chlorination to become suitable for drinking. On the other hand, based on FC data, none of the tested samples for FC was a “high risk”, but 57% of them were categorized with “simple” to “moderate risk” and 43% were “no risk” cisterns. A cistern owner’s survey was utilized to reveal the roots behind this contamination. Different remediation measures, such as cleaning cisterns and rainwater collection surfaces and discarding water from the first season storm, were recommended to enhance and protect the cistern water quality.