SEDIMENT AND RUNOFF CONTROL ON CONSTRUCTION SITES USING FOUR APPLICATION METHODS OF POLYACRYLAMIDE MIX

Fifteen small bare plots (1 meter x 1 meter) on a 10% slope were analyzed for runoff and sediment yield on a construction site. A rainfall simulator applied 6.32 centimeters of rainfall per hour to each plot after a polyacrylamide mix (PAM mix CFM 2000*) treatment was applied. The following treatments: No PAM mix applied to dry soil (control), PAMmix in solution applied to dry soil, dry PAM mix application to dry soil, PAM mix in solution with mulch/seeding applied to dry soil, and PAM-mix in solution applied to moist soil. Each treatment was repeated on three plots. When a solution of PAM-mix with mulch/seeding was applied to dry soil and compared with the control (no PAM-mix application to dry soil), we found an average reduction of 93% in sediment yield. An average reduction of 77% in sediment yield was the worst performing PAM treatment, and occurred when PAM-mix in solution was applied to moist soil. The application of dry PAM-mix to dry soil reduced sediment by 83% and decreased runoff by 16% when compared to the control. Our results show that regardless of the application method, PAM-mix was effective in reducing sediment yield in the test plots. The ease of applicatjon, low maintenance, and relatively low cost associated with PAM make it a practical solution to the costly methods being implemented today 6. CONCLUSION Our results show that, regardless of the application method, PAM-mix was effective in reducing sediment yield in the test plots. The most effective method of soil treatment throughout this study in reducing sediment yield is PAM-mix in solution with mulch/seeding applied to dry soil. The ease of application, low maintenance, and relatively low cost associated with PAM-mix makes it a practical solution to costly existing methods being implemented. The evidence from the field application in this study reflects that PAM-mix is a tool to reduce soil loss on bare soil until vegetation cover is established. The primary factor that must be considered in future studies is the time of polymer solution preparation and application. It was noted that the optimal application procedure is to prepare the solution immediately prior to application. This procedure is necessary in order to limit the amount of degradation and maximize the performance of the PAMmix. Table 1. Summary of rainfall, infiltration runoff, and sediment yield for replication #l.