Water Quality Performance of In-Series BMPs

Abstract

The need to provide adequate water quality control using best management practices (BMPs) requires accurate modeling in order to determine their ideal placement within the watershed. A case study in the Montréal area used PCSWMM software to analyse the implementation of green roofs, rain gardens, pervious pavement and vegetative swales, individually as well as in possible combinations, by comparing both outfall hydrographs and pollutant removal rates to assess the performance of each alternative.Of the individual BMPs, rain gardens provided the highest levels of runoff control, with slight performance improvements when they were coupled in series with green roofs, but with lower performance when adding pervious pavements. The overland flow path could significantly affect which pollutants were picked up by runoff, but to accurately model complex buildup and washoff processes requires information that might not be readily available for all watersheds. Even though the results can be highly case specific, the results obtained highlight the limitations still faced by water-resources professionals, and raise important points that challenge common conceptions regarding BMP implementation. More data on real life performance over long periods of time is still needed to better analyse BMP combinations.

Rainwater harvesting potential in a semiarid Southern California city

“…The routing mechanisms of SWMM transports the runoff at different time steps through a node-link conveyance system representing pipes, channels, storages, and outfalls (USEPA, 2016). The model has been used to study the impacts of urbanization (Aryal et al, 2016), best management practices (Talbot et al, 2016;Vittorio & Ahiablame, 2015), climate (Shrestha et al, 2014), and for quantifying pollutant loading (Aceves, Fuamba, & Angui, 2017;Li, Sharkey, Hunt, & Davis, 2009).…”

The Effectiveness of Centralized versus Decentralized Green Infrastructure in Improving Water Quality and Reducing Flooding at the Catchment Scale

“…An alternative approach to empirical and field studies for assessing catchment scale GI performance is to use a rainfallrunoff model (see for example Di Vittorio and Ahiablame 2015;Carvallo Aceves et al 2017). As with site level studies, the results of these modeling studies also vary with GI type, site and pollutant as well as land use type and location (Jefferson et al 2017).…”

Laboratory results and mathematical modeling of spore surface interactions in stormwater runoff

“…Developing numerical models that include the stormwater-driven fate and transport of spores can be useful to predict contamination extent as it evolves over time during emergency response and recovery, informing activities such as creating sampling maps, deciding where to stage waste, and developing strategic decontamination plans (Mikelonis et al, 2018). Conventional stormwater models have been used to predict water quality concentrations of common contaminants, such as solids or metals, at various points in a conveyance system (McPherson et al, 2005;Smith et al, 2007;Tiveron et al, 2017;Aceves et al, 2017;Lee et al, 2010). However, existing models have not been used to model the fate and transport of low probability, high consequence pathogens, such as B. anthracis.…”