Efficiency of a retention/detention basin to removecontaminants from urban stormwater

Abstract

Retention/detention basins are commonly used to remediate runoff from road surfaces in an attempt to remove contaminants before these materials enter adjacent waterways. However, the efficiency of such devices in removing contaminants is not well known, especially for Australian conditions. The efficiency of a retention/detention device adjacent to a major motorway in Sydney (Australia) was assessed for total suspended solids (TSS), a suite of trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn), nutrients (TP, TKN, NO x , TN) and faecal coliforms. The mean removal efficiency of Cu, Pb, Mn and Zn was 23, 41, 43 and 41%, respectively, whereas the mean reduction in Cr, Fe and Ni concentrations was only 0, 3 and 1%, respectively. TSS in stormwater entering the retention/detention basin was highly variable resulting in large variations in removal efficiencies (range: 712 to 93%; mean: 40%). The mean removal efficiency of Kjeldahl nitrogen (TKN) and total nitrogen (TN) was high (56 and 28%, respectively) in contrast to total NO x and total phosphorus (TP) (742 and 75%, respectively). Faecal coliform was low to very low (55000 cfu/100 ml) and removal efficiency was 16 to 68%. Possible leaching of fine terrigenous particles from the gravel bed of the retention/detention basin may have contributed to the increase in Cr, Fe and Ni concentrations in effluent stormwater.

Water Quality Improvement and Pollutant Removal by Two Regional Detention Facilities with Constructed Wetlands in South Texas

“…However, the median TSS influent concentration in the Morris RDF (150 mg/L) was substantially higher than the McAuliffe RDF (93 mg/L) as it serves a relatively bigger basin (4 times higher than the McAuliffe RDF) with a higher percentage of high-density impervious cover (17.1%). For the rainfall that occurred on 9 January 2013, the lowest TSS effluent concentration achieved from the Morris and McAuliffe RDFs was 15 and 13 mg/L, respectively, which were considerably below the normally expected discharge concentration from a conventional facility (30 mg/L) [10,43]. It is important to note that the inlet modification with the installation significantly enhanced the depletion of TSS concentration.…”

“…It is important to note that the inlet modification with the installation significantly enhanced the depletion of TSS concentration. In conventional detention facilities, the primary mechanism of pollutant removal is sedimentation resulting from gravitational settling [43]. Several factors can influence the variability in the quality of effluents achieved in RDFs through the sedimentation process.…”

Contaminated soil and sediments in a highly developed catchment-estuary system (Sydney estuary, Australia): an innovative stormwater remediation strategy

“…These data were selected mainly from Australian and New Zealand case studies (Fletcher et al 2004;Birch et al 2004Birch et al , 2005Birch et al , 2006Birch and Matthai 2009) to emphasise local conditions and devices, however an extensive North American database is included (CWP 2007).…”

Conceptualizing a decentralized stormwater treatment system for an urbanized city with improper stormwater drainage facilities

“…Stormwater has been considered as a major pollution source for many urban waters (Davis et al 2001;Birch et al 2006). Quantification and characterization of stormwater are important for the design of the stormwater treatment system and recharge well (Taebi and Droste 2004;Birch et al 2005).…”