Author(s): Habib Ahmari; Ashish Bhurtyal

Linked Author(s): Habib Ahmari

Keywords: Stormwater; Bioswale; Expanded shale; Water quality; Suspended sediment

Abstract: Runoff from roads and bridges is a significant source of pollutants released into surface waters. Removal of sediment is considered as one of the main objectives of best management practices (BMPs) because of the widespread impact of sediment on water quality and aquatic habitat degradation. Not all conventional BMPs are capable of total suspended solids (TSS) removal to a certain level in order to meet water quality criteria. Moreover, in intensively developed urban areas, where land resources are limited, installation of conventional BMPs is either impractical or cost prohibitive. Several emerging technologies with smaller footprints are available and can be utilized in those areas, but the cost of installation, operation, and maintenance of these systems is significantly higher than that of conventional sediment removal structures. In this research, a series of scaled laboratory experiments were conducted to evaluate the potential application of expanded shale as an infiltration medium in bioswales to treat roadway runoff. The reduction in TSS and turbidity (Tu) was assessed under different inflow rates, sediment loading, and infiltration layer dimensions. The results show that TSS and Tu were reduced by 65% –79% and 22% –53% in the water infiltrated through the infiltration layer, and 32% – 63% and -7% –47% in water leaving the swale through the outlet weir. Considering the limited length of the swale and depth of the infiltration layer, the observed levels of reduction in TSS and Tu are significantly higher than that of full-scale swales installed in the field.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p1477-cd

Year: 2023