Water Resources Research Act Program

Details for Project ID 2009MO100B

Developing Guidelines for Polyacrylamide Use for Erosion and Runoff Reduction

Institute: Missouri
Year Established: 2009 Start Date: 2009-03-01 End Date: 2011-02-28
Total Federal Funds: $44,000 Total Non-Federal Funds: $93,372

Principal Investigators: Clark Gantzer, Allen Thompson

Project Summary: Erosion can be a serious problem, especially where sloping soil are bare, such as construction locations. Annual damage caused by water and wind in on- and off-site areas is approximately $44 billion (in 1992 US dollars) in the United States (Pimentel et al., 1995). Landscape can contribute to this problem when there is excessive slope, such as during highway embankment construction. Bare soil during such development is often the source of sediments that degrade surface waters (USDA-NRCS, 2005). As slope steepness increases, runoff and potential for sediment transport increase. For bare soil, erosion doubles as slope steepness increases from 5% to 30%. The use of soil stabilizers, such as polyacrylamide (PAM), hold promise as a conservation practice for reducing runoff and erosion in disturbed areas, and has been the focus of recent studies (Flanagan et al., 2002a, 2002b; Thompson et al., 2001*; Lentz and Sojka, 2000). The Natural Resources Conservation Service (NRCS) guide sheet states that PAM can be used with slopes 2.5:1 or flatter, and recommends that PAM application rates may need to be adjusted based on soil properties, slope, and the type of erosion targeted (USDA-NRCS, 2006). However, actual PAM effectiveness for various soils and slopes has not been sufficiently quantified to develop useful guidelines to insure economical use of this conservation practice. Work by Gantzer et al. (2008*) has increased our understanding of the interactions between PAM and specific soil characteristics to improve guidelines of PAM usage for soils located near potential highway construction sites. This study examined PAM, and PAM with and without gypsum to evaluate the effectiveness of PAM, and if gypsum improved bonding of PAM with the soil. Results indicate that differences in runoff and erosion between soils of medium and fine textures, and of acid and neutral soil pHs were all significant. Based on the selected PAM levels, we concluded that the 20 kg ha-1 PAM plus 5 Mg ha-1 gypsum treatment was the best for overall erosion control, reducing sediment loss up to 74%. However, performance differed for soils of varying pH and texture, therefore these factors should be considered to attain effective PAM application. Results from this work were instructive, but insufficient to quantify general guidelines for site-specific PAM use. The goal of this study is to quantify the PAM application effectiveness for reducing runoff and sediment loss on a variety of disturbed soils with differing texture, pH, mineralogy, and slope slopes. Research on this topic will provide needed data to synthesize model development of beneficial guidelines for PAM use for erosion control in construction areas.