The boundary condition at the bottom is assumed so that there is no particle entrainment in the flow from the bottom and there is no particle deposition on the bottom, i.e., particles remain in suspension motion all the time. The path of an initially marked particle is followed as it goes through statistical field variables. Many such paths are used to compile the probability distribution by an ensemble average. Two types of results are obtained: (1) the mean and variance of particle displacement in the flow direction; and (2) the probability density function of particle coordinates. Concentration distribution in time and in two space coordinates is computed through the data of probability density function of particle coordinates. Simulation results are compared, quantitatively, with the presently available information.