Effective Stormwater and Sediment Control During Pipe Line Construction Using New Filter Fence Concept
EPA Grant Number: X83-2428-01Description:
Objective: Turn currently ineffective silt fence technology to highly efficient sediment control system.
Approach: Design, build and test proposed new technology silt fence. Evaluate the new design under laboratory and field testing.
Expected Results: New silt fence design that is effective in trapping sediment and a set of specifications for mechanized installation of the new technology silt fence.
Key Words: Silt fence, Sediment control, Stormwater control, Waste management, Stormwater pollution control.
Sediment has recently become an emphasis in the EPA NPDES storm water rules because of its impact on habitat and the macro-invertebrates in stream channels. This is particularly critical for pipelines and other linear construction since no effective control techniques are currently available (EPA, 2002). The current sediment control BMP technology for linear construction is primarily limited to silt fence. However, many studies have found silt fence to be practically ineffective (EPA 2002, Barrett et al.1995, and Barfield and Hayes 1992, 1997). We propose a major modification to current silt fence technology with the potential to minimize fence failure from structural instability and scour along the toe and the potential to improve the trapping of fine silts and clays through the use of polyacrilimides (PAMs) introduced into the runoff. In the first year, the new concepts were evaluated in laboratory and field studies to assess hydraulic properties and effectiveness in trapping sediment. Algorithms to model the new design will be completed by the end of year1, laboratory studies of PAM are underway, and a prototype vibratory plow system to install fence has been developed in cooperation with Charles Machine Works (Ditch Witch) and operated under field conditions. During the second year, we will continue field tests at the USDA Hydraulic laboratory to optimize the hydraulics and PAM emplacement, establish study sites at linear construction sites to validate the methods, develop BMP specifications and design aids which will incorporate applicable regulations, and evaluate manufacturability and economic feasibility.
The final outcome of the project will be a new technology that is effective in trapping sediment and a set of specifications for a mechanized installation system. We will also continue working with our industrial partner, Charles Machine Works, to enhance the mechanical installation system, which is progressing toward commercial production, by adding a system for installing and removing posts.