Section 2: Solute transport 1. A soluble pollutant of concentration 0.5 gl' was inadvertently spilled on the ground. a. Suppose that the pollutant is nondegradable, nonvolatile, not taken up by plants, not adsorbed by the soil, nor immobilized by any other transport mechanism. If the annual rainfall is 1500 mm, the annual evapotranspiration is 1250 mm, the water table is 20 m deep from the soil surface, and the unsaturated zone has a constant volumetric wetness of 25%, estimate the time required for the pollutant to reach the groundwater. b. If diffusion and dispersion factors are accounted for in the transport of the pollutant, determine the total solute flux if the solute concentration remains constant with depth. Assume bulk density of 1.4 gem", dispersivity of 4.2 cm, and a liquid diffusion coefficient in water of 10% cm's!. c. What percentage of effective dispersion coefficient is accounted for by diffusion vs. hydrodynamic dispersion? d. Describe the effect of the transport mechanisms on the total solute flux