Batch rate and equilibrium experiments were conducted to examine the sorption characteristics of a mixed solute system consisting of para-dichlorobenzene (p-DCB) and 2,4-dichlorophenol (2,4-DCP) to solids from two New Jersey coastal plain aquifer systems. Results were compared to previously reported results obtained for single solute systems. The p-DCB effected a slight enhancement on the 2,4-DCP sorption to the Potomac-Raritan-Magothy (PRM) aquifer solids rather than an inhibitory effect. This was also noted for the adsorption of p-DCB on the Cohansey aquifer solids in the presence of 2,4-DCP. The other systems (2,4-DCP on the Cohansey aquifer solids in the presence of p-DCB and p-DCB on the PRM aquifer solids in the presence of 2,4-DCP) exhibited indiscernable competitive effects. The aquifer solids with the larger organic content adsorbed more of each substance. The data obtained using the more homogeneous aquifer solids evidenced less scatter.