Methodology to Evaluate Performance of Sediment Control Log Filter Media

Abstract

Stormwater management is necessary to protect surface waters from pollutants, and significant amounts of time and money are being expended to purchase and install sediment control logs for this purpose. Testing to compare new innovations in sediment control log filter media and uses has been done; however, more is needed. Whereas testing has traditionally been done using open-channel flumes, a large-scale constant head permeameter was used in this study, and its measurements were compared with testing results from open-channel flume measurements to indicate that this testing method is viable, if not a preferable, alternative. A nonlinear relationship involving the specific discharge was determined in a variety of filter media, including straw, coir, wood fiber, rock, and wood compost. The nonlinear relationship suggests that a nonlaminar flow is occurring within the media. The height of the seepage emerging from the downstream face of a sediment control log was also demonstrated to be a critical measured parameter if an open-channel flume is used as a testing apparatus. This study also included sediment capture testing and revealed that sediment control logs are capable of removing 72% to 92% of suspended sediments by weight, mostly through sedimentation, but with as much as 15% removal through filtration, depending on the media type.