Measurements of the attenuation of neutron and gamma doses in ordinary and ilmenite concrete shields

Seven representative wells in the area including the triangle ''Ben Ghashir-Tajoura-El-Zawia'', Tripoli were selected for this study. Environmental isotope studies indicate that groundwater is recharged through rapid infiltration of rainfall with frequency of recharge less than seven years. Hydrochemical studies reveal that groundwater is of mixed water type between fresh potable meteoric water and deep saline water. Mixing process differs from locality to another resulting in three classes of different water types. The problem of continuous declination of water level and increasing salinity of groundwater was also studied. It is due to exhaustive pumping in the area and is a serious drawback for development. Recommendations for a wise policy of water management are given. (author)