Sediment,Nutrient and Heavy Metal Characteristics of Urban Stormwater Runoff

ReportNo WSAA 139

January 1999

Thisis a joint project between Australian Water Technologies – EnSight (AWT) andthe CRC for Catchment Hydrology (CRCCH). The project involves the monitoringand analyses of event stormwater quality data from three catchments in Sydney –Wolli Creek, Sheas Creek and Bidjigal Creek.

Thismonitoring complements the extensive data from 24 catchments in the Sydney andIllawarra regions collected as part of the Stormwater Monitoring Project (SMP)of Sydney Water Corporation’s Clean Waterways Program. Unlike the SMP, tracemetals (lead, zinc, copper, iron and aluminium) are also analysed in thisproject. This is important because there is little Australian stormwater dataon trace metals. This project also monitors one small catchment that is freefrom sewer overflows – thus providing a direct indication of the stormwaterquality.

Specifically,the aims of this project are to

·        Collect and analyse stormwater quality and quantity data (that includetrace metals) from three catchments in Sydney

·        Characterise the stormwater quality, in particular trace metals

·        Identify relationships between sediment, nutrients and trace metalconcentrations

Chapter2 of this report describes the study, while Chapter 3 presents the monitoringmethod and data analyses. Chapters 4 and 5 discuss the stormwater qualitycharacteristics and the relationship between the water quality parametersrespectively.

Themonitoring in this project also contributes to the data sets for the Australiancapital cities used in a CRCCH research project on estimating pollution loadsfrom urban catchments. The CRCCH research study will be presented elsewhere.Chapter 6 shows an example of daily modelling using the data collected in thisproject, while Chapter 7 explores the possibility of estimating storm washoffloads from rainfall intensity over short time intervals.

Copiesof the Report are available from WSAA, price $A60. Orders may be placed throughthe Bookshop at www.wsaa.asn.au or by email to info@wsaa.asn.au.