Porosity variation was observed to established high predominant heterogeneous concentration in this study, this condition was monitored on development of derived model to monitor the transport to phreatic depositions, such observed condition was found significant by applying nonhomogeneous system in monitoring the rates of Enterobacter transport in sand gravel formation. Linear trend were observed on the validation of the derived model simulation values, but monitoring the rate of porosity reflection on the transport process was when the concentration were plotted against variation of porosity, the lowest soil porosity developed highest concentration, while the highest soil porosity generated lowest concentration of the contaminant, the system from the expression shows the rate at which variation of soil porosity reflect it influence on the growth rate of Enterobacter in sand gravel deposition, the study has significant detailed various rate of porosity effect on the transport process to phreatic beds, the rate of migration also explained various rate of porosity variation based on porous rocks disintegration at various soil matrix, these are structured to develop variations of porous medium in sand grave formations. Such condition has made this paper imperative to monitor the growth rate of Enterobacter transport under the influences of porosity variation in sand grave depositions.