Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate (2016)
Type of ContentJournal Article
PublisherUniversity of Canterbury. Civil and Natural Resources Engineering
Sediment and heavy metals in stormwater runoff are key pollutants of urban waterways, and their presence in stormwater is driven by climatic factors such as rainfall intensity. This study describes the total suspended solids (TSS) and heavy metal concentrations found in runoff from four different urban surfaces within a residential/institutional catchment, in a climate where rainfall is typically of low intensity (< 5.1 mm·h− 1). The results were compared to untreated runoff quality from a compilation of international studies. The road runoff had the highest TSS concentrations, while copper and galvanized roof runoff had the highest copper and zinc concentrations, respectively. Pollutant concentrations were found to be significantly different between surfaces; quantification and prediction of pollutant contributions from urban surfaces should thus take account of the different surface materials, instead of being aggregated into more generalized categories such as land use. The TSS and heavy metal concentrations were found to be at the low to medium end of ranges observed internationally, except for total copper and zinc concentrations generated by dissolution of copper and galvanized roofing material respectively; these concentrations were at least as high as those reported internationally. TSS wash-off from the roofs was seen to be a source-limited process, where all available TSS is washed off during the rain event despite the low intensity rainfall, whereas both road TSS and heavy metals wash-off from roof and road surfaces appeared to all be transport-limited and therefore some carryover of pollutants occurs between rain events. A first flush effect was seen from most surfaces for TSS, but not for heavy metals. This study demonstrates that in low intensity rainfall climates, quantification of untreated runoff quality from key individual surface types in a catchment are needed to enable development of targeted and appropriately sized stormwater treatment systems.
CitationCharters, F.J., Cochrane, T.A., O'Sullivan, A.D. (2016) Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate. Science of the Total Environment, 550, pp. 265-272.
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KeywordsRoof runoff; Road runoff; Total suspended solids; Heavy metals; Metals partitioning
ANZSRC Fields of Research09 - Engineering::0905 - Civil Engineering::090508 - Water Quality Engineering
09 - Engineering::0907 - Environmental Engineering::090799 - Environmental Engineering not elsewhere classified
Showing items related by title, author, creator and subject.
Predicting Event-Based Sediment and Heavy Metal Loads in Untreated Urban Runoff from Impermeable Surfaces Charters, Frances J.; Cochrane, Thomas A.; O'Sullivan, Aisling D. (2020)Understanding the amount of pollutants contributed by impermeable urban surfaces during rain events is necessary for developing effective stormwater management. A process-based pollutant load model, named Modelled Estimates ...
Cadórniga, I.; Cochrane, T.A.; O'Sullivan, A. (University of Canterbury. Civil and Natural Resources Engineering, 2013)Urban stormwater contains substantial amounts of heavy metals (Zn, Cu, Pb) and suspended solids (TSS). Untreated, these contaminants are recognized as the main detriment to urban waterways. To quantify the sources of these ...
Charters FJ; Cochrane TA; O’Sullivan AD (Elsevier BV, 2020)Untreated runoff was collected over multiple rain events from 19 impermeable urban surfaces, including nine roofs, six roads and four carparks, to quantify the differences in water quality due to surface type, age, condition ...