Water Journal : Water Journal September 2012-1
refereed paper water SEPTEMBER 2012 57 potable reuse Conclusions and Recommendations Out of 468 parameters monitored in PRW from 2009 to 2012, this approach identified 20 parameters in Category 1 and 27 in Category 2 (the bulk of these due to inadequate method detection limits and not actual detection in PRW), with the remaining 421 in Category 3. Improvement of analytical methods is currently being investigated for several parameters where the current method detection limit is either higher or too close to the guideline value to allow a sufficient margin of safety. These outcomes inform the ongoing review of the PRW monitoring program in terms of selection of chemical parameters and analytical method development. Future work will focus on the development of an integrated and adaptable fate and hydrodynamic modelling process to more accurately predict removal from the system using current environmental variables and consider baseline monitoring for the high priority chemicals to establish the background in the receiving environment prior to any PRW discharge. Issues associated with the application of the PBT profiling (e.g., the adequacy of PBT triggers and classification, methods to determine PBT characteristics of inorganic chemicals) also require further investigation. Additionally, a PBT chemical below the detection limit may still become a problem in the long term if it consistently enters the water supply, even with a margin of exposure of >10. As a precautionary measure, it may be warranted to run any chemicals that are known to be partially removed by the advanced water treatment train in PBT Profiler, even if this chemical was not detected during monitoring, and determine the importance of PBT chemicals in the long term (e.g., 20 years). To date, this work has focused on human health risks from exposure to PRW via drinking, and the conclusions are framed in a human health context. An ecological health assessment could also be conducted to determine potential ecological risks in the receiving environment (e.g., from nutrients, change in electrical conductivity, change in light regime, and chemical levels that may be safe for intermittent human health exposure via drinking water, but not constantly exposed aquatic wildlife) by comparison with the ANZECC guidelines. Acknowledgements This research was funded by Seqwater (Queensland Bulk Water Supply Authority). Seqwater is the bulk water supplier for the South-East Queensland region and is responsible for catchments, water storages and water treatment plants. The Authors Dr Frederic Leusch (email: f.leusch@griffith. edu.au) is a Senior Lecturer at Griffith University and Program Leader for Water Quality and Diagnostics at the Smart Water Research Centre. His research focuses on the development of bioanalytical methods for water quality assessment, health risk assessment of recycled water, endocrine disruption and the application of toxicogenomics and proteomics to environmental science. Duncan Middleton (email: dmiddleton@seqwater. com.au) is the Recycled Water Quality Coordinator with the Water Quality and Environment team at Seqwater. Duncan manages the Recycled Water Management Plan for the Western Corridor Recycled Water Scheme. Dr Michael Bartkow (email: firstname.lastname@example.org. au) is a Senior Research Scientist with the Research, Science and Technology group at Seqwater. Michael co-ordinates the delivery of research projects related to the management of catchments, water storages and treatment services to ensure the quality of the region's water supplies. His work focuses on issues relating to the impact of chemicals and pathogens on maintaining acceptable water quality in raw and treated water. References Gibbes B & Grinham A (2010): Application and testing of a three-dimensional hydrodynamic model of Lake Wivenhoe using the ELCOM modelling platform. Internal report to Seqwater. Hawker DW, Cumming JL, Neale PA, Bartkow ME & Escher BI (2011). A screening level fate model of organic contaminants from advanced water treatment in potable water supply reservoir. Water Research 45, pp 768--780. Khan SJ (2010): Quantitative chemical exposure assessment for water recycling schemes. Waterlines Report No 27, March 2010. National Water Commission, Canberra, ACT, Australia. Sharma VK, Anquandah GAK, Yngard RA, Kim H, Fekete J, Bouzek K, Ray AK & Golovko D (2009): Nonylphenol, octylphenol and bisphenol A in the aquatic environment: A review on occurrence, fate and treatment. Journal of Environmental Science and Health A, 44, pp 423--442. UKEA (2005): Environmental risk evaluation report: 4-tert-Octylphenol. UK Environment Agency, Bristol, UK.
Water Journal November 2012-1
Water Journal August 2012