Assessment of groundwater quality in Borana Zone, Ethiopia: A multidimensional analysis using groundwater pollution index, nitrate pollution index, and water quality index

This study assessed groundwater quality in Yabelo, Elewaye, Gomole, and Duduluk towns in Ethiopia, analyzing 60 samples across 19 physicochemical parameters. The groundwater pollution index (GPI), nitrate pollution index (NPI), and water quality index (WQI) were used to evaluate drinking water suitability. Results showed turbidity, pH, bicarbonate, nitrite, and copper levels were within the World Health Organization recommended limits. However, 20% of the samples had high total dissolved solids and sulfate levels. Total hardness exceeded limits in 60% of the samples, and 40% had elevated nitrate concentrations. Chromium and fluoride were elevated by 10%, while total iron and manganese exceeded standards by 20%. The GPI indicated “Insignificant pollution” in 80% of samples and “Low pollution” in 20%. Among the samples, the NPI classified 50% as “Clean”, 10% as “Low pollution”, 30% as “Moderate”, and 10% as “Very high pollution”. The WQI rated 20% as “Good”, 30% as “Very good”, and 50% as “Excellent”. This study provides valuable insights to help authorities in identifying protective measures and treatment methods for water resources.