Erosion and Sediment Control
Effectively Enhancing BMPs Using Anionic Polyacrylamide (PAM) Including Coastal Disaster Recovery Methods
Erosion and sediment control Best Management Practices (BMPs) are used to meet and comply with stormwater regulations and keep pollutants from migrating off site. Although generally successful, these BMPs often fail to meet turbidity standards when fine particulates and colloidal particles are present. These fine particulates and colloidal particles wash into lakes, rivers, streams, and other valuable water resources. Increases in turbidity, as well as sediment associated contaminants (metals, nutrients, bacteria, etc.) lead to surface water degradation and associated toxicity can have detrimental effects on aquatic life. Anionic polyacrylamides (PAMs) are a safe, effective and cost effective method for erosion and sediment control as well as stormwater management. Using anionic PAM and PAM based technologies in conjunction with traditional storm water and erosion control BMPs can optimize their performance to meet discharge and turbidity goals. In turn, we can greatly minimize the amount of sediment and other forms of turbidity leaving sites during and after land disturbing activities, as well as reduce turbidity and contaminant concentrations in receiving aquatic systems. This presentation will cover three major categories utilizing Polymer Enhanced Best Management Practices (PEBMPs): (1) prevent erosion and sedimentation by capturing or retaining the sediment before it can migrate off site, (2) use polymer enhancement in conjunction with circulation/mixing systems, dewatering ditches, or other mixing devices to remove turbidity from contaminated waters and (3) if sediment has been deposited or sediment basin capacity is diminished, use polymer enhancement to remove unmanageable muck through de-mucking and sediment thickening. Anionic PAMs have proven highly effective in erosion control and water treatment applications and using polymer enhancement in conjunction with other BMPs has resulted in 70-85% reductions in inanimate phosphorus as well as >95% reductions in total suspended solids (TSS) and turbidity (NTUs). This presentation will detail and illustrate the most common and effective Polymer Enhanced Best Management Practices that have been quantified and are currently being used across various geographical locations to control erosion and sedimentation as well as overall water quality including turbidity reductions. These applications include soil stabilization including soft armoring technique, inlet protection, Sediment Retention Barriers (SRBs) for perimeter control, de-mucking and de-watering systems including dewatering ditches, tank systems, and in basin/pond applications. A primary focus will be on the use of PAM technologies for coastal stabilization of beach sands for coastal highway restoration following hurricane damage. A case study, Highway 98 DOT Project, will be highlighted to show the performance ability of polymer enhanced technologies as well as the overall cost effectiveness.