HR: 1340h
AN: H53C-1399    [Abstracts]
TI: Performance Probability Distributions for Sediment Control Best Management Practices
AU: * Ferrell, L
EM: lferrell@rohan.sdsu.edu
AF: San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4701, United States
AU: Beighley, R
EM: beighley@mail.sdsu.edu
AF: San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4701, United States
AU: Walsh, K
EM: kwalsh@mail.sdsu.edu
AF: San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4701, United States
AB: Controlling soil erosion and sediment transport can be a significant challenge during the construction process due to the extent and conditions of bare, disturbed soils. Best Management Practices (BMPs) are used as the framework for the design of sediment discharge prevention systems in stormwater pollution prevention plans which are typically required for construction sites. This research focuses on commonly-used BMP systems for perimeter control of sediment export: silt fences and fiber rolls. Although these systems are widely used, the physical and engineering parameters describing their performance are not well understood. Performance expectations are based on manufacturer results, but due to the dynamic conditions that exist on a construction site performance expectations are not always achievable in the field. Based on experimental results product performance is shown to be highly variable. Experiments using the same installation procedures show inconsistent sediment removal performances ranging from (>)85 percent to zero. The goal of this research is to improve the determination of off-site sediment yield based on probabilistic performance results of perimeter control BMPs. BMPs are evaluated in the Soil Erosion Research Laboratory (SERL) in the Civil and Environmental Engineering department at San Diego State University. SERL experiments are performed on a 3-m by 10-m tilting soil bed with a soil depth of 0.5 meters and a slope of 33 percent. The simulated storm event consists of 17 mm/hr for 20 minutes followed by 51 mm/hr for 30 minutes. The storm event is based on an ASTM design storm intended to simulate BMP failures. BMP performance is assessed based on experiments where BMPs are installed per manufacture specifications, less than optimal installations, and no treatment conditions. Preliminary results from 30 experiments are presented and used to develop probability distributions for BMP sediment removal efficiencies. The results are then combined with spatial and temporal distributions of perimeter sediment loadings for a construction site to estimate the time dependent risk of off-site sediment discharge over the duration of a project (ex., 0, 25, 50, 75 and 100 percent complete). The results are used to highlight the importance of considering all phases of construction when developing stormwater pollution prevention plans.
UR: http://spatialhydro.sdsu.edu
DE: 1815 Erosion
DE: 1861 Sedimentation (4863)
DE: 1862 Sediment transport (4558)
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2007 Fall Meeting