Subsurface Mapping of Groundwater Contamination Pathway at Using Very Low Frequency Electromagnetic Method at Waste Site of Kubanni Basin, Zaria, Kaduna State

Groundwater contamination result from solid waste and leachate produced on daily basic by human activities. The increase in population led to indiscriminate disposal and mismanagement of this waste in most of the society. Geophysical survey is carried out in order to reveal the presence of subsurface structure that enhance hydraulic contact between the leachate and the groundwater. Very low frequency electromagnetic method (VLF-EM) was used to map the pathway for groundwater contamination at waste site of kubanni. Three profiles of VLF-EM reading were taken at 5m intervals along the profile. The aim is to investigate the structural zones or permeable zones that may serve as groundwater contamination pathway. The Microsoft excel and Fraser and Karous-Hjelt filtering software were used to interpret the result. The crossover point were observe at 85m, 95m, 110m and 135m which indicate good conductive ground which is an indication of contaminant plume zones. The point of maximal negative in both the in-phase and out-phase are 170m and 165m, revealing substantial fracture in the form of a dyke. This fracture can serve as the pathway for the contaminant to seep into the groundwater. The contaminated plume zones will move through the fractures in the subsurface to contaminate the underground water.