1343 † To whom correspondence should be addressed. E-mail: vigid.vigneswaran@eng.uts.edu.au Korean J. Chem. Eng., 27(5), 1343-1359 (2010) DOI: 10.1007/s11814-010-0387-0 INVITED REVIEW PAPER Urban stormwater quality and treatment Rupak Aryal*, Sarvanamuthu Vigneswaran* ,† , Jaya Kandasamy*, and Ravi Naidu** *Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007, Australia **CRC CARE, Mawson Lakes, South Australia 5095 (Received 23 June 2010  accepted 14 August 2010) Abstract−Stormwater runoff from urban and suburban areas generates numerous pollutants. The areas include resi- dential areas, parks, commercial areas, industrial areas and road/highways. Land use and human activities largely de- termine the nature and level of pollutants. Among the various types of pollutants that can contribute to adverse water quality impact in receiving water bodies, of concern are suspended solids, heavy metals, polycyclic aromatic hydrocar- bons and nutrients. This paper provides a critical review of the characteristics and sources of urban stormwater pol- lutants and the manner in which the pollution occurs. Treatment systems for urban stormwater runoff and for urban stormwater harvesting are discussed. Key words: Stormwater, Heavy Metals, Suspended Solids, Polycyclic Aromatic Hydrocarbons, Nutrients INTRODUCTION It is believed that by 2020, more than half the world’s popula- tion will reside in urban areas. More urbanization will lead to in- creasing imperviousness of the earth’s surface which in turn leads to i) increases in peak flows, runoff volumes, pollutants in the first flush and their peak load and ii) reductions in the groundwater re- charge by blocking infiltration of water into the ground. Reductions of groundwater recharge may cause the decrease in dry weather base flow in water courses and the alteration of the catchment hydrology. In recent times urban stormwater runoff and its associated non- point pollution sources have been considered as one of the major Table 1. Possible sources of pollutants in stormwater runoff Soil erosions Vehicles Human/animal waste Fertilizers Household chemicals Industrial processes Paints and preservatives Solids Metals Oil, greese and organics Nutrients Table 2. Possible sources of pollutants in road runoff Brakes Tyres Frame and body Fuel and oil Pavement De-icing salt Litter Cadmium Chromium Copper Iron Lead Nickel Zinc Org. solids Inorg. solids PAHs