ABSTRACT
The increasing demand in the West Bank of Palestine has put a lot of pressure on the existing water resources. The gap between available water and water needs in the West Bank is more than 300 Mcm/yr. The management option to reduce this gap includes drilling deep wells in the West Bank. Two problems occurred during the drilling: one is that the yield from the deep wells is not going to be achieved as planned and the lower aquifer in eastern part of the West Bank especially up to 10 km from the Dead Sea proved to be saline. In one well the static water level was 210 m bgl and the salinity was that of freshwater from 210 m till 770 m bgl. After that depth, i.e., from 770 till 900 m bgl, the salinity increased to 32,000 mg/l. The transition zone between fresh and saline water was 7 m thick. The total drilling depth of this well was 900 m.
The drilled wells in the West Bank were subject to an extensive investigation programme of lithological logging, geophysical logging, acidisation, pumping tests (one day step draw-down test, 3 day-constant test and recovery test for 3 days), spinner flow under static and dynamic logging, temperature and EC under static and dynamic conditions logging, video camera logging etc. This paper uses the results of these investigations to assess the groundwater potential in the West Bank and to find a solution for the salinity problems. It was concluded that there is a continuous reduction in the sustainable yield of the aquifers due to over-pumping and the saline sections in these deep wells should be cemented.
In the costal aquifer of Palestine the main problems are over pumping, pollution from raw sewage, salinity increase from the phenomenon of saltwater intrusion and saline water upconing. In order to protect the coastal aquifer from pollution and salinity two activities were conducted: the first was to develop a vulnerability map and the second was to simulate numerically the groundwater flow and salinity in the coastal aquifer. These led to develop a protection plan. This paper discusses the different components of the plan. The plan includes water balance analysis, identification of vulnerable zone to pollution, artificial recharge from storm water and reuse of treated wastewater, reallocation and shutting down some wells, skimming and scavenger pumping, wastewater collection and reuse system and rehabilitation of existing wells.
