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

Abstract

Groundwater is an essential and indispensable resource, meeting 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. In this study, a comprehensive collection of 20 samples was obtained from various locations for analysis and evaluation. Hadrochemical facies of this study area showed that out of 20 samples, 90% belonged to a type (Na+-K+-Cl−-SO42−), while only 10% fell into a category (Ca2+-Mg2+-Cl−-SO42−). The Groundwater Pollution Index values ranged from 0.7 to 10.8, with an average of 7.03; about 60% of the groundwater samples analyzed in this study area were classified as highly polluted and unsuitable for drinking purposes. Nitrate index values ranged from −0.9 to 10.5. Approximately 80% of the sampled sites require treatment before consumption. According to the Nitrate Pollution Index (NPI), it is essential to regularly monitor 16 well sites to prevent nitrate contamination resulting from human activities, including waste disposal in open areas and sewage infiltration. This study recommends raising farmers’ awareness of the use of slow-release natural fertilizers made from nitrogen rather than nitrogen-based fertilizers, reducing waste disposal by residents, and maintaining an appropriate sewage network to minimize sewage flow leakage. 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 this study area in order to protect water resources and ensure the provision of safe water to the local population.

Assessment of drinking water quality using Water Quality Index and synthetic pollution index in urban areas of mega city Lahore: a GIS-based approach

“…Synthetic pollution index (SPI) and the water quality index (WQI) are among the most often used methods for classifying and reflecting the quality of the water and pollution risk in a given area. WQI and SPI have been utilized by researchers from several countries to evaluate the water quality in various places 13 , 14 .…”

Assessment of Groundwater Quality Using the Pollution Index of Groundwater (PIG), Nitrate Pollution Index (NPI), Water Quality Index (WQI), Multivariate Statistical Analysis (MSA), and GIS Approaches: A Case Study of the Mnasra Region, Gharb Plain, Morocco

“…The PIG, devised by Subba Rao in 2012 [34], presents a methodological approach to evaluate groundwater quality by assessing the influence of specific variables on its overall quality [35]. This index serves to gauge the relative impact on individual water quality parameters, as detailed in Table 1.…”

Assessing Groundwater Quality and Diagnosing Nitrate Pollution in the Sidi Allal Region: A GIS-Based Approach Utilizing the Groundwater Pollution Index

“…The wells close to the Sebou River and Nador Canal were the most polluted by nitrates from the study area. The findings from a study carried out in the Sidi Slimane region, Morocco [34], indicated that the pollution of water extracted from wells surpassed both Moroccan and global standards to a significant extent.…”

“…Consequently, it is strongly advised to not directly consume water from this area for drinking purposes. The findings from studies carried out in the Sidi Slimane and Sidi Allal regions [16,34] indicated that the pollution of water extracted from wells surpassed both Moroccan groundwater standards to a significant extent.…”