Performance of In-Line Sediment Control Devices Under Field Conditions

Abstract

. A wide variety of structural best management practices (BMPs) has been developed in the last few decades to control erosion-related problems at construction sites. Even though many BMPs exist to control erosion and sediment accumulation, there is very little research on their performance and this is even more pronounced when considering the performance of these devices working together and under field conditions. In an effort to address this issue, this study analyzes the performance of in-line devices installed at six drainage exits of a new highway under construction, all of them located upstream and 1.0 km to 2.5 km far from a surface intake in a public water supply reservoir. Altogether, three categories of devices were studied: gabions, silt fences and turbidity curtains. The performance of each device was assessed based on inspections at the construction site after heavy rains, by visually checking changes in the apparent color of the water and accumulation of sediments. Complementary, water quality monitoring data collected at the water intake were analyzed by comparing two different periods: before (from 2002 to 2007) and during (from 2008 to 2010) the construction of the highway. Results indicated that the six drainage exits with BMPs installed in-line did not affect the quality of the water at the surface intake. In addition to that, although each of these devices could not function properly due to unsatisfactory maintenance and sometimes by their own low filtration rates, all of them contributed to retain sediment and keep it close to the limits of the construction site.