Onsite graywater reclamation and reuse in urban coastal areas : impact on saltwater intrusion reversal -

Abstract

This study explored the reuse of graywater as a potential water supplement to meet shortages encountered along coastal urban areas, where saltwater intrusion is impairing coastal aquifers. Saltwater intrusion is a direct result of overexploitation of groundwater associated with increased demand due to population growth and development coupled with urbanization (less aquifer recharge) and exacerbated by climate change impacts (less precipitation, higher temperatures, and sea level rise). The objective of this research is to assess the potential of graywater reclamation and reuse in urban coastal areas, and to explore feasible techniques for implementation. For this purpose, a field survey questionnaire was developed and administered in a pilot area to characterize current water sources, uses, costs, public satisfaction and perception about water quality, wastewater recycling systems, and willingness to contribute in the installation of such systems. Groundwater samples were also collected from accessible wells to assess water quality and saltwater intrusion. Statistical analysis was performed to define factors that affect people’s perception of graywater reuse and identify patterns that have management implications. The study concluded with management recommendations to integrate graywater recycling as a new source of water that can supplement existing water sources and help alleviate water shortages.