The magnetic proxy approach has proven to be efficient in the assessment of pollution by potentially toxic elements when targeting soils or areas with a homogeneous background where anthropogenic magnetic signals can be easily distinguished. It’s crucial to conduct research on the impact of fly ash on the vicinity of the PLTU in this particular area, as it’s a previously unexplored area. The unique thing about this research is that this PLTU uses coal containing Fe, Pb, and Mg as fuel and has a fairly high susceptibility value for fly ash and bottom ash. This study is due to an analysis of the magnetic susceptibility and heavy metal content in the soil of the area around the Asam-Asam steam power plant (PLTU) of South Kalimantan Province, where geogenic input and fly ash can influence it. Heavy metals that have passed the threshold at all locations are Ti, Cr, Mn, Fe, Ni, Cu, V, and Al. Most of the correlation coefficients are strong and significant between magnetic susceptibility values and heavy metal concentrations at each location. The correspondence between magnetic susceptibility values and heavy metal content reflects the potential of magnetic proxy methods at polluted spots, provided that the lithological conditions are carefully considered.