Contents lists available at ScienceDirect Journal of Contaminant Hydrology journal homepage: www.elsevier.com/locate/jconhyd Solute transport modelling to manage groundwater pollution from surface water resources Shaymaa Mustafa a , Arifah Bahar a,b, ⁎ , Zainal Abdul Aziz a,b,c , Mohamad Darwish d a UTM Centre for Industrial & Applied Mathematics, Ibnu Sina Institute for Scientific & Industrial Research, Universiti Teknologi Malaysia, Johor Bahru, Malaysia b Department of Mathematical Sciences, Universiti Teknologi Malaysia, Johor Bahru, Malaysia c MYHIMS Solutions PLT, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia d School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia ARTICLE INFO Keywords: Analytical solutions Solute transport Groundwater/surface-water relations Contamination Hydraulic conductivity Clogging ABSTRACT This article provides an analytical solute transport model to investigate the potential of groundwater con- tamination by polluted surface water in a two dimensional domain. The clogging of streambed which makes the aquifer partially penetrated by the stream, is considered in the model. The impacts of pumping process, hy- draulic conductivity and clogging layer on the quality of water produced from nearby drinking water wells are evaluated. It is found that results are consistent with numerical simulation conducted by MODFLOW software. Moreover, the model is applied using data of contamination occurrence in Malaysia, where high contaminants concentrations are found close to streams. Results show that the pumping activities (rate and time period) are crucial factors when evaluating the risk of groundwater contamination from surface water. Additionally, this study illustrates that the increase in either hydraulic conductivity or leakance coefficient parameters due to the clogging layer will enlarge the area of contamination. The model is able to determine the suitable pumping rate and location of the well so that the contamination plume never reaches the extraction well, which is useful in constructing riverbank filtration sites. 1. Introduction In many countries, both agriculture and potable water supplies rely heavily, or often exclusively, on clean river water (Kallioras et al., 2006; Schwarzenbach et al., 2010). However, as a result of development and increasing economic activities, the degree of contamination at river water is increased. This pollution may cause detrimental effects on human health and on crop productivity, and lead to groundwater contamination (Kan, 2009; Schwarzenbach et al., 2010). Additionally, the deterioration of river water quality can affect the sustainability of using river water, thus limiting the quantity of potable water supply and increasing treatment costs (Schwarzenbach et al., 2010). Drilling pumping wells for drinking water at locations adjacent to the streams may provide sustainable and economical solutions for river pollution. In fact, the lowering of water table due to pumping process can induce the water flow from surface water to groundwater and then to drinking water pumping wells. When the water passes from the river to the pumping well, contaminant attenuation occurs due to several chemical, physical, and biological processes (Dillon et al., 2002; Maliva and Missimer, 2012). The pumping process and hydraulic conductivity parameters can significantly affect the quality of extracted water. If either the rate or the time of groundwater pumping is increased, the level of con- tamination in the area around the well will raise, which can threaten the drinking water quality (Mustafa et al., 2016). On the other hand, high values of hydraulic conductivity parameter K, which measures the ability of the soil to transmit water, lead to rapid velocities of water and subsequently decrease the quality of produced water(Maliva and Missimer, 2012). In this study, the effect of both pumping process parameters (rate and time) and K value on the management and risk assessment of drinking water contamination from pollutants in surface water were evaluated. This evaluation aims to determine the range of values of these parameters that can be applied when construction a pumping well. The most common and reliable methods for determining K are the slug/bail and pumping tests (Butler and James, 1997; Cheong et al., 2008; Istok and Dawson, 1991). The equations and formulas of these methods were tested in the laboratory and the results showed that K value is affected by several transport parameters such as porosity. https://doi.org/10.1016/j.jconhyd.2020.103662 Received 3 December 2019; Received in revised form 20 May 2020; Accepted 22 May 2020 ⁎ Corresponding author at: UTM Centre for Industrial & Applied Mathematics, Ibnu Sina Institute for Scientific & Industrial Research Universiti Teknologi Malaysia, Johor Bahru, Malaysia. E-mail address: arifah@utm.my (A. Bahar). Journal of Contaminant Hydrology 233 (2020) 103662 Available online 10 June 2020 0169-7722/ © 2020 Elsevier B.V. All rights reserved. T