Sediment is the largest water pollutant by volume and is a leading cause of impairment of streams and other water bodies in United States. Urbanization related construction activities, wherein large areas are disturbed within a short span and sediment loads are hundreds to few thousand times more than agricultural and wooded lands are the principle sources of sediments for the surface waters. Increased turbidity of water has a detrimental effect on aquatic vegetation and organisms, is also visually unattractive and can detract from the recreational uses of the waterway. Sedimentation and turbidity control is therefore not only a concern for the construction industry but also a leading challenge for the water quality researchers. We investigated the effect of clay mineralogy and sediment size contributing towards turbidity generation and their interactions with polyacrylmide (PAM). Shake tests were conducted with a high molecular weight (12 X 10-6 Da) and 15% hydrolysis, anionic polymer (A110, Cytec Inc.), and three clays: montmorillonite, kaolinite and illite, with two cationic compositions: Ca2+ and Na+. Similar tests were done with four soils of mixed clay mineralogies from different physiographic regions of North Carolina, collected from NC Department of Transportation (DOT) construction sites from across the state. The turbidity of 5 g L-1 clay suspensions decreased in the order Illite> Montmorillonite> kaolinite. While the kaolinitic and smectitic clays can generate equivalent turbidities initially, the flocculation is higher with kaolinite. The response to PAM varied with cationic composition and was limited by concentration. Larger size particles seem to enhance flocculation. The interactions between the clay mineralogy, cationic composition and sediment size provided an array of responses which can be used for soil and site specific turbidity control of the waters which are discharged from the construction sites.