Statistical and Analytical Evaluation of Groundwater Quality in Al-Rawdhatain Field

In the arid and semi-arid area, groundwater is a crucial source of water for agricultural and drinking purposes. This study examines the physicochemical parameters of Al-Rawdhatain groundwater wells (18 wells) between 1990 and 2009. For drinking water purposes, analysis shows that pH falls within the safe limits and Mg2+ and K+ values for all tested wells fall within WHO's (2004) permissible limits. In contrast, there were some exceedances in dissolved anions and cations, and almost all the samples tested exceeded the desirable limit of electrical conductivity (EC) and total dissolved solids (TDS), for drinking water purposes. The suitability of water for irrigation purposes has been assessed and analysis showed that 55-60% of the groundwater wells are suitable for agricultural purposes according to sodium adsorption ratio (SAR), Kelly's ratio (KR), sodium percentage (Na%), permeability index (PI), and total hardness (TH) indices. The correlation coefficient matrix between the hydrochemical parameters was carried out using Pearson's correlation. Moderate-strong correlation was observed among the major elements, Na+, Ca2+, Mg2+, Cl-and EC, which clearly identifies the main elements contributing to the groundwater salinity and their tendency to follow a similar trend. In this study, a factor model was developed and results showed that three major processes control the hydrochemistry of groundwater resources in the area: weathering processes, evaporation of minerals from sedimentary rocks, and salination. The Gibbs's diagrams support the factor analysis results. (C) 2013 American Institute of Chemical Engineers Environ Prog, 33: 895-904, 2014