Water quality monitoring is an important part of water management and there are many examples of technical challenges throughout the water cycle from catchment to tap. The application of online monitoring and associated sensors will contribute to several key areas of the water business. Changing environmental conditions mean that the quality of source waters is showing increased variability, and early detection of changes in quality and impacts on the treatment process is vital..

Water quality from the Murray River, Australia, can vary considerably and is expected to become more challenging to treat due to recent drought followed by widespread flooding and future climate change impacts. Better tools are required to help plant operators maintain water quality. Morgan water treatment plant (WTP) operates overnight to take advantage of off-peak electricity, however the stop/start practices add an additional complication to accurate coagulant dosing. Online monitoring and feed forward prediction is ideal in these situations as it can provide information while there is still a chance to make adjustments, unlike the feedback (post-dosing) control achieved with many other methods. Using a multiport sampling arrangement, water quality was monitored at Morgan WTP for a 6 month period. Data were validated against other online parameters and laboratory measured samples. In a comparison of predicted versus actual plant dose, results showed that treatment was optimised when the plant dose was changed in response to product water quality deterioration and eventually matched the prediction, even though this was not known to the operators at the time. The software prediction demonstrated faster reaction to inlet water quality changes and can produce more stable treated water quality. The predicted dose was added to the operator's Supervisory Control and Data Acquisition (SCADA) system for several months as a real-time display to provide an additional tool to aid decision making and instill confidence in the resulting water quality.

group of people who take sewers seriously. A sewer is not just a collector and transport system but also a chemical and biological reactor that must be considered as an integral part of the total urban wastewater system. Traditionally, hydraulics and pollutant transport phenomena of sewer systems have been the main consideration in their design and management. However, sewers deserve a much broader range of considerations to ensure that the overall wastewater system operates effi ciently and effectively to maximise the benefi ts to triple bottom line factors of costs, environment and social aspects. This series of conferences brings together the support and expertise of both the International Water Association (IWA) and the International Association for Hydraulic Research (IAHR) under the Sewer Systems & Processes Working Group (www.sspwg.org) of The Joint Committee on Urban Drainage (JCUD). The JCUD was established in 1981 in recognition of the intrinsic inter-relationship between hydraulic aspects (main focus of IAHR) and water quality aspects (main focus of IWA) in the fi eld of urban drainage. In addition, SPN6 for the fi rst time brings together the knowledge and experience developed through the SPN series of conferences (last held in Deft, Holland in 2007 as SPN5) with the great wealth of knowledge and experience of the Sewer Operation & Maintenance (SOM) conferences (last held in Vienna, Austria in 2006).