Evaluation of Groundwater Quality and Contamination Using Groundwater Pollution Index (GPI), Nitrate Pollution Index (NPI) and GIS

Abstract

<title>Abstract</title> Groundwater is an essential and indispensable resource, meeting the dire needs for drinking and irrigation purposes. The aim of this study is to assess the suitability of groundwater quality for drinking purposes. This evaluation will be conducted using the groundwater pollution index (GPI), the nitrate pollution index (NPI), and the geographic information system (GIS) in Sidi Slimane, Morocco, Morocco. In the study, a comprehensive collection of 20 samples were obtained from various locations for analysis and evaluation. The result of Piper and Gibbs diagrams uncovered that the characteristics of groundwater are shaped by various factors, including the weathering of parent rocks, evaporation, interactions between rocks and water, as well as ion exchange processes. The GPI value ranged from 0.7 to 10.8 with an average of 7.03. These findings indicate that 60% of the groundwater samples analyzed in the study area were classified as highly polluted and unsuitable for drinking purposes. The values of NPI were ranged between − 0.9 and 10.5. Based on the NPI classification, about 80% of the overall groundwater samples obtained are highly polluted, indicating that the groundwater in the study area is unsuitable for drinking purposes. This study plays a vital role in identifying the polluted areas and highlighting the need to take appropriate measures to control the sources of pollution in the study area, in order to protect water resources and ensure the provision of safe water to the local population.