Water released from construction sites often contains large amounts of suspended sediment, resulting in large increases in turbidity in the adjacent streams, lakes, or estuaries. Much of this suspended sediment cannot be settled or filtered by typical systems used on construction sites, but chemical treatment can be used to reduce turbidity. We investigated polyacrylamides (PAM) with a range of charge and charge density for flocculating three soils with different mineralogies, collected from excavated areas on construction sites. Two soils had >20% smectite in the fine clay fraction and generated turbidity which was responsive primarily to cationic and neutral PAMs, with increasing flocculation as the PAM charge changed from anionic to neutral to cationic. The kaolinitic soil was responsive to all PAMs. The flocculation response was much greater for all PAM-soil combinations when whole soil was used compared to only the fraction remaining in suspension after settling, suggesting that the larger particles facilitate the flocculation and settling process. Optimal doses were in the 1-5 mg L-1 range, but the whole soil suspension was also less sensitive to dose. The relative toxicity of the PAMs in an aquatic bioassay was cationic > anionic > neutral. Since the neutral PAM was almost as effective as the cationic PAM for the smectitic soils, it might be a good option for turbidity treatment.