Multiple rainfall event pollution transport by sustainable drainage systems: the fate of fine sediment pollution

Abstract

A key design criterion of sustainable urban drainage systems is to mitigate urban stormwater pollution. Current research defines sustainable urban drainage systems (SuDS) pollutant treatment efficiency through the detention of total suspended solids, urban nutrients and heavy metal pollutants within the system during a design flow event, with research focusing on sand ([2 mm) sediment movement. The impact of multiple rainfall-runoff events on the fine sediment (\2 mm) treatment efficiency of SuDS is not yet well defined, and the temporal movement of detained sediment has not been investigated in detail. The field research presented in this paper addresses this research gap, monitoring ongoing fine sediment transport through a best-practice-designed SuDS network over 12 months through the use of a novel rare earth oxide trace methodology. Through time-stepped monitoring of the fine sediment pollution across three SuDS treatment trains (networks), the following key conclusions have been drawn. (1) That fine sediment becomes re-suspended and re-deposited within SuDS assets and the network as a result of ongoing multiple rainfall-runoff events. (2) That this resuspension continues for over 52 weeks. (3) That by area, linear wetlands (within the monitored networks) outperform wetland and swale assets in multiple event fine sediment detention. And (4) that multiple event monitoring and analysis of fine sediment within a SuDS network highlights the under-performance of SuDS assets against current design event expectations.

Distribution of Chromium and Gallium in the Total Suspended Solid and Surface Sediments of Sungai Kelantan, Kelantan, Malaysia

“…On the other hand, presence of diffusion acting onto surface sediment may increase the overall metal loading in the water column, thus increasing the Ga concentration where diffusion always accommodates the porous media of sediment which becomes more dominant for the sudden increment of metal concentration in the water column (Bucur et al 2006). In the meantime, the continuous sedimentation and re-suspension of these fine sediment particles along the river channel might lead to the homogenous pattern in pollutant loadings of total suspended solids along the river (Allen et al 2017).…”

Linking water quality with amphibian breeding and development: a case study comparing natural ponds and Sustainable Drainage Systems (SuDS) in East Kilbride, Scotland

“…Thus solutions to abate de-icers or partition roads from nearby aquatic habitats can assist in maintaining ecological integrity and prevent salt pollution (Sanzo & Hecnar, 2006;Collins & Russell, 2009;Chambers, 2011;Hopkins et al, 2013;Hua & Pierce, 2013). Isolating aquatic habitats from roads and developed areas may also prevent metal pollution, as heavy metals in urban waterways often originate from transportation areas and vehicles (Allen et al, 2017a;White et al, 2017). Another possible source of elevated metal concentrations may be the submerged refuse observed at sites, including cans, pipes, trollies, bicycles, engine parts, which could leach metals into these environments.…”

“…How amphibians fare in SuDS is relatively unknown as few studies have addressed this topic. SuDS may harbour pollutants due to their proximity to developed areas and exposure to urban runoff, and a recent study found that fine sediments in SuDS networks were resuspended in the water column subsequent to multiple rainfall events (Allen et al, 2017a). These fine sediments can contain salts, metals, and other pollutants that are potentially harmful to aquatic wildlife and can hinder benefits to biodiversity.…”

The short-term influence of cumulative, sequential rainfall-runoff flows on sediment retention and transport in selected SuDS devices

“…delineation between deposited sediment from release 1 and release 3 at a single sample point). Tagging was undertaken following the methodology described in Kimoto, Nearing, Shipitalo, and Polyakov (2006), Polyakov et al (2009), Allen et al (2016) and Zhang et al (2001), using clean sieved sediment and adsorption of selected REO tracer through a cycle of wetting and drying.…”