Characterization Of Borehole Water Quality From A Volcanic Area For Drinking. Case Of The Menengai Geothermal Project Boreholes, Kenya

摘要

Groundwater samples were collected from eight boreholes in Menengai geothermal field located within the East African Rift Valley. The main objective was to assess the suitability of the borehole water for drinking. Physical, chemical and toxicological parameters associated with volcanicity in the water were measured. Samples were assayed for trace element;), Arsenic (As) using an Atomic Absorption spectrophotometer (AAS ) while soluble anions; nitrates (NO3) ,chlorides (Cl~-), and fluorides(F) were analyzed on an Ion chromatograph (IC). Physical parameters were determined in-situ using a pH meter and a combined Total Dissolved Solids (TDS)-Electrical conductivity (EC) -Temperature meter. pH measurement were between 6.3-6.9, at a a temperature of (27°c) TDS, was from 152 -170mg/.l .Measured results were related to the World Health Organization (WHO) and Kenya National Environmental Management Authority (NEMA) regulations for drinking water to assess suitability. Trace metal concentration was below detection limit. Arsenic concentration between 0.01-0.05 ug/1. All physical parameters were within the recommended limits indicating suitability for drinking except fluoride which had concentration above the WHO recommended 1.5 mg/1.