This thesis work focuses on non-reactive solute transport modeling of the akaki wellfieldrnfor two selected groundwater contaminants (chloride & fluoride) for the 25 operatingrnboreholes administered by Addis Ababa Water & Sewerage Authority (AAWSA). Thernwork is conducted based on laboratory analysis of groundwater samples from selectedrnboreholes and based on historical data of the wellfield boreholes.rnThe widespread use of chemical products, coupled with the disposal of large volumes ofrnwaste materials, poses the potential for widely distributed groundwater contamination.rnBecause such contaminations can pose a serious threat to public health, prediction of therndegree of contamination by appropriate numerical modeling tools is vital to aware thernend user from possible risks. Mathematical models solved numerically are the subject ofrnthis thesis work focusing on conservative solute transport in the Akaki well field.rnChloride & fluoride ions predictive modeling of the wellfield for the next ten yearsrn(2007-2017) is made first by calibrating the model input parameters using the availablernhistorical solute concentration data for selected boreholes at various periods. Forrncalibration purpose, initial solute concentration was taken as 3 mg/l for chloride and 0.51rnmg/l for fluoride and MATLAB simulation of chloride & fluoride ion concentration isrndone.rnThe simulation results show that while chloride concentrations in the wellfield getrnincreased; fluoride, however, is getting decreasing through out all of the boreholes in thernwellfield. This is in agreement with the actual observed pattern of solute load of thernwellfield revealing chloride is being introduced in to the wellfield by one or morernmechanisms somewhere in the vicinity of the akaki river catchment (ARC) while fluoridernis not.rnKeywords: aquifers, breakthrough curves, initial conditions, boundary conditions,rncalibration, prediction, conservative contaminant transport, hydraulic conductivity,rnporosity.