Integrated magnetic and hydrochemical forensic assessment of dumpsite-induced soil and groundwater contamination and the possible implications for public health

Abstract Uncontrolled waste disposal in developing nations poses a significant risk to shallow water resources and nearby communities. This study integrated hydrochemical analysis with ground magnetic surveying to assess dumpsite-related contamination around ten dumpsites within the Kaduna Metropolis. Twenty-five water samples, comprising 15 hand-dug wells and 10 rivers/streams within 200 m of the dumpsites, were analyzed for pH, EC, TDS, total hardness, BOD 5 , COD, Fe, and Pb using standard APHA procedures with routine QA/QC checks. A ground magnetic survey was conducted at one representative central dumpsite to map shallow waste heterogeneity. Hydrochemical results showed degraded water quality, with EC (709–2612 µS/cm), TDS (510–1612 mg/L), BOD 5 (371–798 mg/L), COD (697–1477 mg/L), Pb (0.16–1.92 mg/L), and Fe (0.33–2.42 mg/L) commonly exceeding drinking-water guideline values, and surface waters generally more impaired than hand-dug wells. The BOD 5 /COD relationship indicates mixed organic contamination with an appreciable biodegradable fraction rather than “water content.” Magnetic data revealed multiple shallow anomalies (about 0–5 m) related to ferromagnetic debris and heterogeneous fill, but did not by themselves establish leachate chemistry. Overall, dumpsite impacts are best characterized by combining magnetic, hydrochemical, and hydrogeological evidence. Improved waste containment, routine monitoring, and targeted remediation are urgently needed.