The occurrence of high fluoride and arsenic in groundwater

International Conference on Hydrology & Ground Water Expo

September 10-12, 2012 Hilton San Antonio Airport, USA

Weldesenbet S., Wohnlich S. and Wisotzky F

Posters: Hydrol Current Res

Abstract :

The Central Main Ethiopian Rift basin is a continental rift system characterized by volcano-tectonic depression endowed with huge geothermal resource and associated natural geochemical changes on groundwater quality that causes adverse health effect on the people in the area. Chemical composition of groundwater in the study area showed a well defined trend along flow from the highland and escarpment to the rift floor aquifer. The low TDS (< 500mg/l) Ca-Mg-HCO3 dominated water at recharge area in the highlands and escarpments evolve progressively into Ca-Na-HCO3 and Na-Ca-HCO3 type waters along the rift ward groundwater flow paths. These waters finally appear as moderate TDS (mean 960mg/l) Na-HCO3 type and as high TDS (> 1000 mg/l) Na-HCO3 -Cl type in volcano-lacustrine aquifers of the rift floor. The content of δ2H and δ18O in groundwater, surface water and rain water showed that the main recharge water for the geothermal system in the area originates largely from the highlands and escarpments areas.