ABSTRACT
The Dan Region Reclamation Project is the largest wastewater reclamation project in Israel. The wastewater from the Greater Tel Aviv metropolitan area (220 sq. km., 1.5 million inhabitants) is biologically treated, most of it (93%) in an activated sludge treatment plant, and the rest (7%) in recirculated facultative oxidation ponds. On average 303,000 m3 are treated every day. The effluent is then further treated through recharge into the aquifer and subsequent recovery using a special soil-aquifer treatment (SAT) developed at the Dan Region Project. The SAT adds to purification of the effluents by processes of slow sand filtration, chemical precipitation, adsorption, ion exchange, biological degradation, nitrification and denitrification. In addition to the water quality improvement, SAT constitutes a seasonal and multiannual water storage system. Water recovered after soil aquifer treatment is of extremely high quality, and can be used for unlimited agricultural irrigation. In 1997, a total of some 103 million m were recharged and recovered in the Dan Region Reclamation Project, and since 1977 851 million m3 have been reclaimed through SAT.
