Utilization of the Buffering Properties of the Unsaturated Zone in Groundwater Quality Management on a Regional Scale: The Coastal Aquifer of Israel as a Case Study

Abstract

The coastal aquifer is one of the three major sources of the Israeli water system, supplying about 30% of the water consumption and planned to serve as the major long-term storage reservoir. The aquifer is phreatic, with depths to water levels ranging between few meters near the coast, up to 80–90 m at its southeastern parts. A thick bluish clay, named Saqya, forms the impervious bottom of the aquifer system; it rises gradually from 100–200 m below sea level at the seashore to nearly ground level at the Judean foothills in the east. The aquifer itself consists of sand and calcareous sandstone layers of Plio-Pleistocene age intersected with clay and loam lenses. The aquifer is replenished directly by percolating rainfall and return flow of irrigation and wastewater. The Mediterranean Sea is the natural outlet of the aquifer system.