Tracing the Environmental Footprint of Abandoned Quarries: Hydro-Geochemical and Soil Quality Assessment in Kollam, India

Abandoned granite quarries are increasingly recognized as significant contributors to environmental degradation, especially in ecologically sensitive landscapes like Kollam District in Kerala, India. This study provides a comprehensive environmental assessment of three abandoned quarries namely Nadapara, Cherukara, and Vayyanam focusing on hydro-geochemical, water quality, soil quality, heavy metal contamination, spatial distribution patterns and biodiversity disruption. Quarry water samples revealed slightly alkaline pH, high phosphate levels, and total coliforms exceeding 900/100 mL, indicating microbial contamination and eutrophication risk. Soil analysis showed strong acidity, low organic carbon and high bulk density, suggesting severe compaction and nutrient loss. T-tests confirmed significant differences in organic carbon and moisture content across sites. Heavy metals like Fe, Pb, Cr, and Ni, were within global safety limits but exhibited contamination potential due to enhanced mobility in acidic, low-organic soils. Empirical variogram modelling revealed extensive lateral dispersion for Fe and Pb, while Ni and Cr showed localized retention. Correlation analyses highlighted strong negative associations between Fe and organic carbon and significant positive trends between Lead and phosphorus. Biodiversity surveys documented 51 plant species and 25 faunal taxa, indicating ecological resilience despite degradation. These findings underscore the urgent need for remediation through soil alterations, native vegetation restoration, and environmental monitoring to safeguard ecological and human health in quarry impacted regions.