Integrated urban water management (IUWM) is an emerging approach for water utilities to plan and manage urban water systems to minimize their impact on the natural environment, to maximize their contribution to economic vitality, and to engender overall community improvement. It considers All parts of the water cycle The full range of demands for water The full range of water supplies over time The practices that can provide water fit for purpose both in quality and quantity and reduce demand for water The relative sustainability of water service provision Local context and stakeholder views The scale, engineering, and functional aspects of the water system The means by which transition from current practice can be achieved This project will refine, extend, and tailor an IUWM approach developed by the Commonwealth Scientific and Industrial Research Organisation (Australia) to enable its application by U.S. and Australian water, wastewater, and storm water utilities for town or city level IUWM.

The water from rainwater tanks has often been found to have high lead concentrations, in some cases exceeding potable water guidelines. These high lead concentrations were previously linked to the presence of lead flashing on roofs and proximity of roofs to roads and industry. In this study, water and sediment samples were collected from 52 tanks across the Melbourne metropolitan area along with information about the tanks, roofs and the surrounding environment. The results were analysed to identify significant relationships between lead concentrations in tank water, tank sediments and a range of variables collected. Water quality in 14 of the 52 tanks sampled exceeded Australian Drinking Water Guidelines (ADWG) for lead concentrations. It was found that lead flashing, prevailing winds, proximity to roads and commercial zones had statistically significant relationships with lead concentrations in rainwater tanks, thus implying that no single source is the sole cause of high lead concentrations.

A comparison of chemical versus biological package greywater treatment systems was undertaken using a new laboratory based protocol that included a synthetic greywater formulation that mimics average bathroom and laundry greywater in Australia. The results for chemical, nutrient and metals removal showed that the treatment systems behaved very differently under the test conditions. The chemical system was able to remove most of the components of greywater that could be detrimental to the environment and produced high quality product water. The biological system was only able to remove some of the components of the greywater, and did not produce the same quality of product water. However, the product water quality was found to improve continually over the duration of testing. It was concluded that for the current composition of Australian greywater the chemical based technology produced the highest quality product but that other environmental costs, such as chemical use and energy also need to be assessed. If greywater compositions change with the use of more biodegradable, low environmental impact personal care and cleaning products, biological treatment systems may be better suited to treating greywater in the future.

Accurate estimation of the levels of microorganisms in urban stormwater is needed for stormwater harvesting and, possibly more importantly, to ensure that our streams and bays are safe for recreational uses. The aim of this research was to develop and test a simple, yet accurate, urban stormwater microorganism model. The microorganism model is spatially lumped and coupled to a simple rainfall runoff model. The surface and subsurface components of the new microorganism model simulate build-up and wash-off of microorganisms from (a) the impervious surfaces of the catchment and (b) the stormwater pipes, respectively. The model has been tested using a large Escherichia coli dataset collected from four urban catchments in Melbourne, Australia. For each catchment, around 20 well sampled pollutographs were available. The results of the model are promising, with good predictions in both instantaneous flow rates and E. coli concentrations. Furthermore, event E. coli peaks and loads were also estimated with high accuracy together with event mean E. coli concentrations. The model is undergoing further testing and development, including sensitivity, validation and uncertainty analyses.

The development of a model that predicts the levels of microorganisms in urban stormwater will aid in the assessment of health risks when using stormwater for both recreational uses and as an alternate water resource. However, the development of such a model requires an understanding of the dominant processes that influence the behaviour of microorganisms in urban systems. Using simple and multiple regression analyses this paper determines the dominant processes which affect the inter-event variability of the microbial indicator Escherichia coli (E. coli) in four urbanised catchments. The results reveal that a number of antecedent climatic conditions, together with rainfall intensity, can significantly explain the inter-event variation in wet weather E. coli levels.

Rainwater tanks are viewed as an available source of alternative water supply at the house scale that can help overcome the widespread problem of water scarcity in Australian cities. Building standards, government support and incentives encourage the installation and use of rainwater tanks in new and existing houses. Robust design of rainwater tanks is important to limit the problems that owners and occupants may face when using rainwater tanks, reduce maintenance requirements and help ensure the on-going optimal performance of these rainwater tanks. This paper presents results of laboratory experiments on a full scale tank that were undertaken to investigate the effect of sediment accumulation and tank design on the resultant outlet water quality. The experiments were run using several sediment thicknesses, tank water levels and outlet configurations. Preliminary results found that the content of particles in the outlet water sample, measured as TSS concentration, was sensitive to the height of the outlet relative to the base of the tank and to the depth of sediment in the tank. An outlet positioned nearer the base of the tank resulted in a higher quantity of sediment in the outlet sample, confirming that sediment re-suspension occurs during inflow events. These results, together with ongoing investigations of inlet positions, will help in the development of design solutions that mitigate the impacts of sediment accumulation and re-suspension on the end use water quality.

Roof run-off collected in rainwater tanks is often found to contain heavy metals and other chemical pollutants. The level of contamination is influenced by air pollution (wet and dry atmospheric deposition), and roof and guttering materials. Location has also been found to influence heavy metal concentration in the rainwater tanks due to proximity to traffic or industrial areas. Six pilot roofs (approximately 3.7m{2}) connected to PVC tanks (0.1kL), were monitored for one year, with water and sediment samples being taken every three months. The roofing types were glazed tile, paint coated metal sheeting, corrugated galvanised sheeting, each with and without approx. 0.24m{2} lead flashing. The six pilot roofs are situated at the same location, in a suburban area of Melbourne, thereby discounting any variation of water quality because of location. Both the water and sediment samples were analysed for heavy metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). In the water samples, Cr, Fe, Mn, Ni and Pb concentrations exceeded the Australian Drinking Water Guidelines (2004) values. In the sediment samples, all metals were found in very high concentrations, implying that should sediment re-suspension occur there will be impacts on the end use water quality. The high concentrations of all metals in sediment classified it as 'prescribed soil' requiring appropriate disposal at licensed sites.

Rainwater tanks are being installed to supplement centralised urban water supply systems in Australia in order to reduce domestic potable water usage. Large scale installation of rainwater tanks in urban areas can result in the transfer of ownership, operation, and maintenance of part of the water supply system infrastructure from urban water authorities to property owners and occupants. Good design of rainwater tanks is required to limit the problems that householders may face when using rainwater tanks, ensuring the long term success of their installation. Previous studies have consistently found heavy metals from roof run-off being delivered into the rainwater tanks and accumulating in the sludge at the bottom of the tanks. Rainwater tanks used in Australia have an outlet zone which is typically situated at the interface of sludge and settling zone, creating a risk that previously settled sediment (and bound heavy metals) is mobilised during rain events, resulting in heavily polluted water being delivered to the end use. This paper reviews the current state of knowledge relating to heavy metals in the water supplied from rainwater tanks. It also provides an overview of the field and laboratory based research which is being currently undertaken to investigate the extent of sediment mixing and re-suspension during rain events and implications for the quality of the water delivered from the tank. In addition, preliminary comments are made about the options for improving rain tank design to provide better quality water to households.

This paper presents the water and contaminant daily simulation model of the total water cycle, called UVQ. The model has been developed to provide a means for rapidly assessing conventional and non-conventional approaches to providing water supply, stormwater and wastewater services to urban allotments, neighbourhoods and catchments. The model is placed in the context of other such models developed internationally through a brief literature review. This is followed by a description of the model and a case study, which is used to illustrate the utility of the model. UVQ is an effective tool for assessing the impacts of urban development options on the total water cycle, as well as the performance of a wide range of non-conventional demand and supply side management techniques. It compliments other aspects of an environmental assessment of options, along with more traditional aspects such as infrastructure costing.

As urban stormwater is becoming a popular alternative water supply, the human health risks associated with microorganisms in stormwater need to be better understood. This paper presents a study of the Escherichia Coli (E. coli) levels in urban stormwater at five sites within Melbourne, Australia. Samples were taken from stormwater drains, and analysed for E. coli, an indicator of faecal contamination. Both wet and dry weather samples were analysed and there was significant variation in E. coli levels between and within sites. The highest E. coli levels were observed in the residential catchments, lower E. coli levels were observed in the industrial catchment and the lowest level was observed in runoff from a roof catchment. Possible sources of E. coli are identified and the results suggest that the site with the highest E. coli level was contaminated with sources of human origin, whilst the sites with the lowest levels were likely contaminated by sources of animal origin.

As the industry moves from segregated management of water supply, stormwater and wastewater servicing to integrated urban water management, practitioners require new tools to conceive and implement new servicing approaches. The Water Smart Communities - Planning and Performance project is developing a range of software programs, databases and frameworks for decision making and analysis to provide tools for the Australian water industry to meet this need. The project sits within the Water for a Healthy Country Urban Waterscapes program. This paper presents a selection of the research tasks that have been initiated in the first eighteen months of the Water Smart Communities - Planning and Performance project, illustrating the diversity of research activities being undertaken.