This model simulates the transport of contaminant mass (Zinc and Cadmium) from a spoils pile to a nearby river and simulates the mixing of the contaminated outflows from spoils pile, transported in both the solid and liquid phases, with uncontaminated upstream flow. The Contaminant Transport Module is used to simulate mass transport and a coupled fluid flow network is developed for calculation of inflows and outflows in the transport pathway network. The rainfall runoff process from the spoils pile and surrounding watershed is calculated using simplistic assumptions that need to be modified for use on a real project. The amount of water, contaminants, and spoil material is calculated as it moves from the spoil heap to a river. The model is run as a Monte Carlo simulation to determine the probability of peak concentration and contaminant loading amounts.