title: Management of Recycled Water Quality in the Urban Environment
Creators: name: Higgins, Jennifer
Publisher: name: Griffith University
Year: 2010
Subjects: subject: Recycled water quality
subject: water recycling policies
subject: risk assessment

description: A rapid expansion in use of recycled water in urban Australia has occurred over the last decade, prompted mainly by a reduction in water supplies due to drought, increasing awareness of the impact of climate change on water resources and changes in government water recycling policies. This expansion has resulted in a 117% increase Australia wide in the reuse of effluent from wastewater treatment plants by major water authorities. This study describes the developments in recycled water quality, from 1999 to 2009, during its progress from ‘treated effluent’, to ‘reclaimed water’, to ‘recycled water’ and then to ‘purified recycled water’. The developments studied include changes in people’s concerns about recycled water quality, changes in the benchmarks of water quality, as described in water recycling guidelines and effluent discharge licences, and changes in recycled water quality during storage in open ponds. This study also describes preliminary investigations into a novel approach, of applying a microbial source tracking technique, to follow changes in water quality during conventional wastewater treatment processes and storage in open ponds. Concerns about recycled water quality were examined by distributing a questionnaire in mid-2000 to providers and users of recycled water in Queensland. Four out of five respondents had concerns about aspects of recycled water quality including microbiological components (viruses, parasites and bacteria), salinity related components, aggregate components (pH and solids), nutrients and organic components (pesticides and endocrine disruptors). One in four respondents expressed concern about quality variability, particularly those from low population density areas. One in five users had observed quality changes during distribution to the point-of-use including nutrients, chlorine, suspended solids, colour and odour. Half of the providers and one in five users in 2000 proposed to expand their usage of recycled water in the near future and one third of the non-user respondents proposed to commence using recycled water in the following 5 years. Guidelines for the use of recycled water were reviewed in 2003 and, at that time, the national, State and Territory guidelines contained similar recommendations, for hazard identification and risk assessment, using controls implemented through treatment and management practices. However, despite the framework provided by the national guidelines, the State and Territory guidelines differed from them concerning sources of recycled water, reuse options, nominated quality criteria, monitoring frequencies, sampling and testing methods and accreditation. Legislation for effluent from wastewater treatment plants discharged to the environment varied between States and Territories and, in most cases, the licences were site specific. The general differences in discharge licences and reuse guidelines included the location of monitoring sites, nominated water quality criteria and compliance levels. At the completion of this review, the authors proposed that establishment of recycled water schemes could be enhanced by standardisation of the water quality monitoring requirements for effluent discharge, particularly for indicator organisms, with those for effluent reuse through collaboration between licensing and guideline authorities. It was also proposed that a single point of contact for recycling scheme approval be established, in each State or Territory, and that the national guidelines for reclaimed water be better integrated with those for fresh and marine water. Developments in the years since the survey and review were undertaken have been summarised, including the usage, acceptance and quality of recycled water and the latest changes in recycled water guidelines.