Assessing drinking water quality in Eloued, south-East Algeria, using the groundwater pollution index (GPI) and the synthetic pollution index (SPI) model

• Published in: Environmental monitoring and assessment 2024-11, Vol.196 (11), p.1019, Article 1019
• Main Authors: Zair, Nadjet, Attoui, Badra, Miloudi, Abdelmonem, Abderrahmane, Khechekhouche, Souyei, Belgacem
• Format: Article
• Language: English
• Subjects: Algeria; Anions; Aquifers; Atmospheric Protection/Air Quality Control/Air Pollution; Biodegradation; Biodiversity; Calcium ions; Carbonates; Cations; Chemical composition; Chemical elements; Developing countries; Drinking water; Drinking Water - chemistry; Earth and Environmental Science; Ecology; Ecotoxicology; Elements; Environment; Environmental degradation; Environmental Management; Environmental Monitoring - methods; Evaporation; Geographical distribution; Geographical information systems; Groundwater; Groundwater - chemistry; Groundwater pollution; Groundwater quality; Guidelines; International standards; Ions; LDCs; Magnesium; Monitoring/Environmental Analysis; Multivariate statistical analysis; Nitrogen dioxide; Phosphates; Physicochemical processes; Physicochemical properties; Pollution index; Principal components analysis; Relative abundance; Salts; Silicates; Sodium; Statistical analysis; Statistical methods; Sulphates; Urbanization; Water analysis; Water demand; Water Pollutants, Chemical - analysis; Water pollution; Water pollution monitoring; Water Quality; Water quality assessments; Water sampling
• ISSN: 0167-6369; 1573-2959; 1573-2959
• DOI: 10.1007/s10661-024-13137-5

Groundwater quality degradation is a significant environmental issue worldwide, with potentially severe economic consequences and harm to ecosystems and biodiversity. This can directly affect human health, particularly in developing countries where rapid and uncontrolled urbanization is on the rise. Groundwater is the primary resource for meeting the water needs of the Eloued region, located in southeastern Algeria. Water is considered unfit for human consumption if its physico-chemical elements exceed national or international standards or guidelines. We used the GPI and SPI indices to evaluate the quality of groundwater suited for drinking. Groundwater samples were obtained from 22 wells at depths of more than 250 m. Standard analytical procedures were used to determine the physicochemical characteristics of the collected samples, which included pH, EC, TDS, Na + , Ca +2 , Mg +2 , K + , Cl − , HCO 3 − , SO 4 −2 , NO 3 − , NO 2 − , NH 4 + and PO 4 −3 . Multivariate statistical analysis and GIS techniques were used to process the results. The results of the selected physicochemical parameters were compared with World Health Organization (WHO) guidelines to determine the quality of drinking water. The findings indicate that the waters of the terminal complex aquifer are salty and contain medium to high quantities of main ions that surpass the established drinking water limits. The primary ions’ relative abundance is Cl −  > SO 4 −2  > HCO 3 −  > NO3 for anions and Na +  > Ca +2  > Mg +2  > K + for cations. Groundwater chemical types were dominated by Na + , Ca +2 , Cl − , and SO 4 −2 . Principal Component Analysis (PCA) showed that alteration and dissolution of carbonates, evaporates, salts, partly silicates, and evaporation, are the main reasons affecting the chemical composition of water in Eloued. The GPI results show that 18.18%, 54.54%, and 27.27% of the water samples were classed as lightly polluted, moderately polluted, or substantially polluted for drinking purposes, respectively. According to the SPI study, 9.09%, 36.36%, 36.36%, and 18.18% were considered drinkable, mildly contaminated, moderately polluted, and seriously polluted for drinking purposes, respectively. According to the GPI and SPI models’ geographical distribution maps, potable water is generally scarce and concentrated in the northeastern section of the research area, near the town of Ourmes.