Groundwater Quality Assessment Using Water Quality Index and Multivariate Statistical Analysis Case Study: East Matrouh, Northwestern Coast, Egypt.

Abstract

Abstract The groundwater quality deterioration is a global phenomenon due to the effect of contaminated surface water. This study covers the investigation of groundwater quality using the contamination indices, statistical analysis, and hydrochemical facies. Thirty-one water samples that representing the water resources in the study area were collected and analyzed for chemical compositions. There are two aquifers; Pleistocene and Miocene. From the obtained data, the electric conductivity (EC) values ranged from 8520 to 19410 μS/cm in Pleistocene aquifer. While in Miocene aquifer, it ranged from 4290 to 7920 μS/cm. The wide variation is due to interaction with aquifer rocks. The hydrochemical facies evolution diagram (HFE-D) indicated that the majority of samples belong to an intrusion phase; the Na-Cl facies represents the state of the aquifer and the remaining sample is scattered in the field of freshening. The dominance of average cations is about Na+ > Mg2+ > Ca2+ > K+, where the anion dominance average is in the imperative of Cl− > SO42− > HCO3-. Multivariate statistical techniques, such as cluster analysis (CA) and factor analysis (FA) showed contamination with heavy metal and fecal due to the influence of the sewage treatment plant. The spatial distribution of heavy metal pollution index (HPI), Ecological risk index (ERI) and pollution index of groundwater (PIG), in the southeastern portion of the research, revealed high values near the center and particularly in the northwest portion of the study region. It demonstrated that water in the northeast of the study area is likely to be influenced by heavy metal leaching from the water treatment plant.