Sediment retention devices (SRDs) include silt fence, wattles, filter logs, compost socks, and various types of storm water inlet protectors, and are a widely used BMP to provide sediment filtration in stormwater runoff while allowing water passage. However, SRD performance varies greatly with regard to flow rate and filtration efficiency. Unfortunately, SRDs are frequently selected without an objective, quantitative means of knowing if the device can be expected to be sufficiently effective in providing the desired balance between flow rate and filtration efficiency. There is a limited, but growing, body of performance data related to the flow rate and filtration capabilities of SRD products based on recognized standard ASTM test procedures. SRD flow rate and filtration performance can be accurately evaluated using the bench-scale standard test method, ASTM D 5141, “Standard Test Method for Determining Filtering Efficiency and Flow Rate of the Filtration Component of a Sediment Retention Device Using Site-Specific Soil”, or in large-scale “as installed” conditions using the standard test method ASTM D 7351, “Standard Test Method for Determination of Sediment Retention Device Effectiveness in Sheet Flow Applications.” These test methods quantify both the sediment removal efficiency and the associated flow rate of an SRD, so that the potential for either excessive sediment loss or the back-up of runoff can be assessed. This paper details both the bench-scale (ASTM D5141) and the large-scale (ASTM D7351) test procedures, presents robust data on the comparative performance of a variety of SRDs, and provides insight into the appropriate usage of these products in design. Consequently, this paper will demonstrate the ability of these test methods to differentiate product performance and, in so doing, enable specifiers to engineer the appropriate SRD system to provide the desired balance between flow and sediment retention during construction operations.
Comparative Performance of SRDs under standardized test methods
Understand the filtration and flow relationship of SRDs for use in design
Determine the appropriate SRD for a project based on test results