Depositional seals formed by fine sediments deposited at the soil surface can greatly reduce soil infiltration and hydraulic conductivity (HC). These seals also lead to runoff, erosion, and sediment transport to nearby waterways. Column experiments were performed to study the effects of depositional seals, formed on a smectitic, calcareous silt loam through leaching with 5 g L-1 suspensions of pure Na- or Ca-montmorillonite, -kaolinite or -illite, on the HC of the soil. The effects of introducing polyacrylamide (PAM), in dry (20 kg ha-1) or liquid (0.5 mg L-1) form to the soil surface prior to depositional seal development, on mitigation of the permeability of the seal formed was also studied. Four North Carolina soils with mixed mineralogy, from Tide Water, Coastal, Piedmont and Blue Ridge physiographic regions were also tested for characterization of the degree of suspension flocculation, seal development and effects of PAM. The seals developed in the PAM treatments generally had higher HC than without PAM, with the effectiveness of PAM for mitigating seal development varying with the mineralogy and cationic composition. The HC values for the seals developed with all Na-clays were lower than with Ca-clays, but the effects of using PAM in mitigating seal development were more pronounced in the Na saturated clays, particularly in suspension containing kaolinite or illite. Relative flocculation of the suspensions was not well correlated with the HC responses, but floc density appeared to be important. The study emphasizes a need to consider the mineralogical composition of soils for enhanced soil specific sedimentation control.