Evaluation of water quality of goundwater recharge in Wadi Feifa, Southern Jordan Valley, Jordan

Abstract

A study was carried out during winter 2007-2008 at Ghor Feifa Jordan Valley weir to estimate the quantity and quality of artificially recharged water originating from wadi Feifa surface runoff due to construction of diversion weir at its downstream. Results showed that there was a meaningful relationship between the quantity and quality of the stream feeding the diversion weir and groundwater quality exist. The amounts of water recharging local aquifers were estimated to be 0.15 m 3 /m/h. The major ionic concentration of the water in the investigated site at different periods indicated that there is an increase in TDS during the first two months of the investigated period due to no rain during November and December 2007; thereafter, during January and February 2008 a decrease in all ionic concentrations in both surface and groundwater was observed. This dilution effect is due to recharge during rainfall periods on the mountainous region of Tafileh area. Stable isotopic composition of water collected from surface and groundwater showed that both sources of water are plotted near the Eastern Mediterranean Water Line (EMWL) indicating same origin of water which is rain water without strong evaporation effect. The tritium concentration of both surface and groundwater were less than 1 TU (tritium unit) indicating that the most probable source of water in the investigation area is from old groundwater in form of base flow in addition to treated wastewater. Results also showed that the recharge rate ranged from 0.05 to� 0.21 m 3 /m. These results were in agreement with the measurements of static water level recorded in the monitoring wells downstream as the water level raised about 5 cm within three months which is located very close to the diversion weir.