Water quality indices for the evaluation of the groundwater quality in southwestern Libya

An investigation was undertaken to consider the quality of the groundwater. The samples were collected from the Southwestern Libya. Forty-one water samples (41) were analyzed for hydrochemical characteristics and suitability for drinking purposes. The parameters for water quality, including calcium, magnesium, sodium, potassium, chloride and bicarbonate, sulfate, nitrate, pH and total dissolved solids (TDS), were examined. The most common worldwide used standard (ST-WQI) and the weighted arithmetic (WA-WQI) water quality indices were selected. The majority of the samples (87.5% wells) described the quality of groundwater in the Alshatti area as excellent to moderate and in the Ghat region (three wells) water quality ranges from excellent to good and is appropriate for direct consumption. In the Wadi al-Ajal areas, 62.5% (10 wells) of samples described the groundwater quality as excellent to good and the rest of the others were poor or unsuitable water. In contrast, most of the obtained results from the Sabha and Ghadduwah areas showed poor to unsuitable water quality for drinking use. Furthermore, samples are higher with pH and alkalinity values. The alkalinity does not pose a health risk but can cause esthetic problems. Generally, most of the areas’ water quality indices for physicochemical parameters indicated suitability for drinking purposes.