Physicochemical fingerprinting of cemetery-induced groundwater pollution around Dandolo Cemetery, Kano

Abstract

This study presents a forensic hydrogeochemical assessment of groundwater quality around Dan Dolo Cemetery, one of the largest burial grounds in Kano Metropolis, northern Nigeria, where thousands of residents depend on shallow wells and boreholes for domestic water supply. Thirty groundwater samples were collected from boreholes and hand-dug wells within and around the cemetery during the dry season, when dilution effects are minimal. In situ measurements of pH, electrical conductivity (EC), total dissolved solids (TDS), and temperature were obtained using a calibrated multimeter and analyzed. The results show that groundwater in the study area is predominantly acidic (pH 5.41–7.90), with approximately 70% of samples failing WHO and Nigerian drinking water standards. EC values ranged from 140 to 2480 μS/cm, while TDS varied between 99 and 1770 mg/L, indicating widespread ionic enrichment and salinization. Cluster analysis and hierarchical dendrograms identified three hydrochemical groups representing background recharge zones, cemetery-affected mixing zones, and a highly contaminated plume extending from the cemetery toward Kansakali, Jakara, and Kwatawa. More than 40% of samples exceeded regulatory limits for EC, and 45% exceeded TDS standards, while 80% of wells exhibited elevated temperatures, consistent with organic decay and shallow aquifer conditions. The hydrochemical signature and compliance patterns provide strong evidence that Dan Dolo Cemetery acts as a point source of groundwater degradation within the urban aquifer system.