Assessing the Impact of Brahmapuram Landfill, Kochi, Kerala, India, on Groundwater Quality: A Physicochemical, Correlation, and Statistical Analysis Using WQI

Groundwater contamination from industrial effluents, agricultural runoff, and landfill leachate threatens water quality and public health. Aligning with United Nations Sustainable Development Goal 6 (UN SDG 6) on clean water and sanitation, this study evaluates groundwater quality in and around the Brahmapuram landfill (Kochi, Kerala, India) with respect to Indian and World Health Organization (WHO) standards. Comprehensive physicochemical analysis, water quality index (WQI) assessment, correlation matrix, and statistical evaluations were conducted to analyze key water quality parameters. WQI analysis indicated that 40% of the samples exhibited poor to very poor quality, rendering them unsuitable for direct consumption without treatment. Spatial distribution maps for pH, temperature, color, total alkalinity, total hardness (TH), chloride, sulfate, dissolved oxygen, biochemical oxygen demand (BOD), and turbidity were developed using QGIS, contamination hotspots were identified. A strong correlation between TH and sulfate (r = 0.83) suggested common contamination sources. Significant variations in chloride and hardness levels were also observed. The findings highlight the urgent need for leachate control, sustainable water management, and stricter landfill regulations, particularly following incidents such as the Brahmapuram landfill fire outbreak. Beyond its regional significance, this study provides a replicable framework for assessing landfill-induced groundwater pollution and supports evidence-based governance.