Most people agree that using recycled sewage water to irrigate public open space and sportsfields is a good use of this valuable resource. It reduces demand on potable supplies and provides good quality turf surfaces for sport and recreation when natural rainfall is insufficient. The benefits to the public are there to be seen.

However, despite this apparent consensus about recycled water, there are some fundamental questions that need to be answered before new recycled water schemes can get off the ground. This presentation discusses these issues using illustrations from a couple of recent schemes in Victoria that RMCG has been involved with.

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A thermal biosolid dryer has been installed at the Ballarat North Water Reclamation Plant (BNWRP). The BNWRP was constructed in 2007 and is designed for 8.4ML/d of combined industrial wastewater and domestic sewage. There are no sludge digestion facilities and Waste Activated Sludge (WAS) is discharged direct to a thickening centrifuge which produces a 3% dry solid sludge. Dewatering centrifuges then dewater the sludge to 18% dry solids which is the feed material for the thermal dryer. The dryer uses natural gas as the fuel for a rotating drum kiln. Biosolids are dried from 18% dry solids to 92% dry solids and approximately 80T per month of dry pelletised biosolids are produced for reuse.

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Yarra Valley Water (YVW) commenced operation of the Aurora Class A Recycled Water Treatment Plant (RWTP) in March 2009. The plant produces Class A recycled water fit for dual pipe recycling in accordance with the Victorian Environment Protection Authority (EPA) and the Department of Human Services (DHS) requirements. The validation assessment of the Aurora RWTP’s process train was completed in-house by YVW’s engineering staff. This assessment confirmed that the plant provides the required 7 Log reduction of viruses and 6 Log reduction of protozoans from the plant’s feed water. This paper details YVW’s experiences relating to the validation assessment including key challenges, the pros and cons of undertaking the validation assessment work in-house, the value of existing validation data and future operation within the current recycled water management regulatory frameworks.

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Goulburn Valley Water’s response to replacing the electrical and control systems and chemical dosing works destroyed by the Black Saturday fires. This task was done in five days using largely internal resources. Good planning was critical to the success of the project.

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Terang WTP Trident System consists of two up flow or adsorption clarifiers and two of multi media filters. Flow through the plant varies from 15L/sec 24 L/sec in each cell. Typical Raw quality is 1.50 to 3.50 NTU turbidity and 10 to 30 Hazen units, True Colour.

The primary water treatment chemical is Aluminium sulphate, which is supplemented, during the period of low raw water alkalinity, by a Cationic polymer. The addition of the Cationic polymer also improves filter and adsorption clarifier run time. Pre and Post pH correction is achieved
with Soda Ash.

The waste system comprises of a 200 KL tank, which include sludge disposal systems and a polymer dosing system that is used to increase the Backwash and adsorption clarifiers waste floc size and to reduce the floc settling time. With the improvement in the supernatant quality the plant is able achieve supernatant return flows of between 15 and 50 % of the raw water plant inflows without a detrimental affect on the filtered water quality.

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This paper is being presented not as a highly technical paper, but it is what it is, and what has happened in the South East Queensland Water Industry during the last 12 months or so. The reformation processes that have occurred, and also the new vision for the future of the water supply industry in this area, can, and no doubt will be beneficial one in the long term. It is not the be all or end all of happiness and/or frustrations, but if we keep focused on what is required of us as individuals, together we will make it work.

Motto: You have to be serious about what you are required to do, but you do not have to be serious in how you do it. Keep smiling.

Prior to presenting this paper I would just like to make it clear that the content is derived from my experience in water treatment operations as a “hands-on” worker from the coalface. There is no intended malice towards any individual, or “finger-pointing” towards any level of government.

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The Bendigo water treatment plant (WTP) is one of the three WTP’s which form the AQUA 2000 contract between Veolia Water Australia (VWA) and Coliban Water, to supply safe and reliable drinking water to Bendigo, Castlemaine and Kyneton. Recent drought conditions in central Victoria have severely impacted upon Coliban Water’s catchments and hence an alternative secure water supply has been needed for Bendigo. As a result alternate supplies such as the Waranga Basin have been drawn upon via the newly constructed Goldfields Super pipe. These new water sources have created a considerable variation in raw water quality compared to that for which the Bendigo WTP was originally designed to treat.

Initial assessment of the Waranga water quality entering the Sandhurst reservoir revealed variations in colour, turbidity, alkalinity, and metals concentration. In order to adapt to these changes we have considered a number of options for upgrading process elements, such as the lime dosing facility and implementing a greater capacity to manage increasing volumes of water treatment sludge. These variations have serious implications on our daily operations and contractual obligations to Coliban Water, including extra water sampling and analysis, higher chemical usage along with additional staffing resources to conduct process optimisation trials. This paper will provide an overview of the challenges faced by the introduction of new water sources to the Bendigo system along with the process investigation and optimisation implemented to meet these challenges.

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In recent years, operation of the Healesville Sewage Treatment Plant had become increasingly difficult, in particular, achieving the EPA licence limits of both Ammonia and Total Nitrogen. Further development was proposed in the catchment area, including a micro-brewery so plant upgrades appeared imminent. Yarra Valley Water engaged a third party to provide a calibrated modelling package to simulate the existing treatment process and the effect of the proposed additional loading.

The information gathered provided a firm basis for plant optimisation options and enabled informed investment decisions. In conjunction with the modelling simulation, an online Ammonia/Nitrate analyser was installed to gather real time information on treatment process performance. This paper discusses the model calibration process, review of the outcomes and benefits from having the process modelled and summarises the operational benefits from gathering online Ammonia and Nitrate measurements.

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Under EPA Discharge Licenses, Yarra Valley Water discharges STP effluent to stream which eventually flows via the Yarra River to Port Philip Bay. Nutrient loads in streams and in Port Philip Bay are an ongoing issue and methods of reducing these loads are continually being investigated. One method of reducing the nutrient loads in the bay is to decrease the levels of nutrients entering the water networks through upstream discharges. During late summer and autumn 2008 a methanol dosing trial was conducted at Lilydale STP to assess the possibility of using methanol for enhanced denitrification.

A total nitrogen limit of 10 mg/L is in place at the plant and under normal operation effluent total nitrogen levels of 4.5 to 7 mg/L are generally achieved. This paper outlines the procedure used to dose the methanol during the trial period, the sampling regime undertaken to compare nutrient levels in dosed with un-dosed effluent and any process impacts or changes observed while methanol was being dosed at the STP. Results of the trial showing a 40% reduction in total nitrogen levels are also detailed in this paper.

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In response to its obligations under the SDWA and ADWG, Goulburn Valley Water (GVW) adopted specific turbidity targets for potable water and carried out a risk assessment of water supplies to the communities within its service area. Six small towns utilising only settling dams and disinfection prior to customer supply were identified as having water quality risks. GVW determined that membrane filtration was the appropriate treatment option to minimise those risks. A project was initiated to select the membrane filtration process that would be most suitable for all six small towns and to construct the initial membrane filtration plant at Girgarre.

Girgarre is a small town ~40 km west of Shepparton with raw water supplied from the Goulburn Murray Water channel system. This paper describes the process undertaken by the team comprising GVW, the consulting engineer, Parsons Brinckerhoff Australia (PB) and the contractor, Haulton Water Services (HWS) to successfully complete this important project. The key issues covered include the drivers for the project, a review of the various membrane filtration technologies, the selection process used to determine which treatment process to use and a report on the on-going performance of the plant.

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Managed aquifer recharge (MAR) is the controlled infiltration or injection of water into an aquifer. Infiltration methods can include infiltration ponds or trenches and a variety of other types of infiltration techniques, whereas injection is carried out using a bore (injection well) or series of bores.

Aquifer Storage & Recovery (ASR) is a type of MAR, whereby water is injected via a well during times when water is available, and recovery of the water from the same well during times when it is needed. Generally, injected water is stored in the aquifer for a period of time before being recovered again.

ASR has the potential to enable the better utilisation of water resources that are currently under-utilised such as storm water and recycled water. Subject to suitable geology, ASR can provide large volumes of storage with small surface infrastructure footprints. Barwon Water is investigating the use of ASR for water storage and has programs in place to assess the viability of aquifers in the Anglesea area over the next 2 years, along with studies into aquifers closer to Geelong for this purpose. Barwon Water sees ASR as a way of increasing the flexibility of supply options as part of an overall water supply strategy for the region.

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In the summer of 2006/07 Yarra Valley Water (YVW) was faced with increased water fault volumes and a shift in customer perception as a result of drought conditions combined with tough water restrictions. A review was undertaken to optimise the fault call resolution process before December 2007 in order to minimise negative media and negative customer feedback. Actions implemented were:

• Increased Resources & Equipment
• Programmed Works (Leak detection & Valve insertions)
• Central Management of Bursts & Leak Backlog
• Scripting & Prioritisation
• Customer Call Back & Feed back Calls
• Proactive media program.

The summer of 2007/08 showed a huge improvement due to a combination of the above combined with lower volumes. The customer callback program in particular proved to be a resounding success, greatly reducing negative media and customer feedback.

The process was fine tuned and reapplied when the summer of 2008/09 hit. Unprecedented hot weather resulting in extremely high fault volumes and the bushfires put all the changes to the test. The result was positive, enabling the Backlog of jobs to be reduced in half the time of the 2006/07 summer. Again negative media and customer feedback was noticeably less.

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Sewerage networks are a vital part of any Water Authority’s asset base. To guarantee public safety significant capital and human resources are invested in the operation and maintenance of sewerage networks to ensure their efficient and effective operation. In Victoria the Essential Services Commission (ESC) is the economic regulator for the Victorian Water Industry and one of its roles is to approve and monitor service standards. A key service standard that is measured is the number of sewerage blockages per year with the unit of measure being number of blockages per 100KM of main.

Sewer blockages caused by tree roots is a common problem and can have a major impact on service standards and escalate public health risks. According to the ESC 75% of Yarra Valley Water’s sewer blockages were caused by tree root infiltration. Traditionally a combination of preliminary cleaning techniques via jetting and cutting has been used in association with chemical treatment via foaming. To improve current practices with the focus on value for money and the environment Bartlett’s Waste Management and Central Highlands Water have undertaken an extensive trial utilising new innovative technology to treat root intrusion. The patented technique combines CCTV with a spot spray process that effectively targets areas affected by root intrusion. This paper outlines the technique, its benefits and discusses the results to date of the trial undertaken by Central Highlands Water and Bartlett’s Waste Management at Maryborough.

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The use of computational fluid dynamics (CFD) has proven useful in optimising the design of water storage tanks. In particular, the use of CFD helps to ensure that short-circuiting within the tank does not occur or is minimised, which is vital to maintain correct residence times and eliminate storage dead zones. CFD allows the modeller to manipulate inlet and outlet pipe positions and angles, add baffles or other innovative concepts and rapidly view the results.

A skilled CFD practitioner can produce outputs that are highly visual, user friendly and simple to understand. The advantages of CFD are its flexibility, relatively short computational times and overall cost effectiveness. In addition to confirming tank design, CFD is frequently used to model pump wet-wells, drop structures, energy dissipation structures, spillways and weirs. CFD modelling is relatively inexpensive and has a proven track record for providing substantial capital cost savings and affording assurance of design. CFD is no longer seen as a daunting technology and is a cost effective addition to the design process.

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South East Water (SEW) has over 900 Hydrant Permit holders who take water from hydrants throughout the network for various purposes including road construction, dust suppression, street sweeping, cleaning drains and sewers, filling water tanks and tree watering.

The administration of Hydrant Permit Holders for SEW has previously been very complex and labour intensive. In addition, problems and issues associated with withdrawing water from hydrants, such as burst mains and water quality complaints were not being captured due to the inefficient approach.

A solution was needed for this growing problem. SEW engaged Australian manufacturer Aegis to develop a simple, cost effective device using existing technology. This presentation will outline the case study from issue identification and solution design, to the results of a pilot program conducted on mobile tankers with Hydrant Permit holders.

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The Victorian ‘Black Saturday’ fires in 2009 caused serious damage to water and wastewater assets operated by Goulburn Valley Water. This paper outlines the emergency response actions that took place to restore services to customers. It also details lessons that were learnt which can be used to minimise future fire damage and improve the response during any future fire emergency.

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Black Rock water reclamation plant is the largest plant of its type operated by Barwon Water in Geelong, Victoria and services approximately 250,000 customers. The plant is an Intermittently Decanted Extended Aeration (IDEA) plant, with an average dry weather capacity of 70 ML/day and a peak wet weather capacity of 210 ML/day. The treatment process consists of coarse screening to 65mm followed by fine screening down to 3mm. From here the influent goes to four 25 ML biological treatment tanks which operate on a four hour treatment cycle consisting of two hours of aeration followed by one and a half hours of settling and 30 minutes of decanting.

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Access to training and assessment for water industry operations personnel continues to be problematic. With the introduction of national training packages, minimum industry performance standards have been developed. However, it remains difficult for industry to progress its personnel to desired levels of performance, in the absence of suitable training and assessment.

While there are approximately 20 or so, Registered Training Organisations (RTOs) who have included the water training package on their scope of registration, many of them have not developed, or do not have access to resource materials which support delivery and assessment. And generally, the organisations that have resource materials have in most instances specialised,for example, the delivery of training and assessment for the treatment stream only.

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The Wimmera Mallee Pipeline Project was required to deliver piped raw water to supply the township of Natimuk. GWMWater planned to build a treatment plant in 2012. Innovative thinking by the design team identified options to bring drinking quality water from Horsham, eliminating the need for a treatment plant and generating savings of nearly $4 M. As the design proceeded, further improvements meant that Natimuk could be supplied under gravity from Horsham’s treatment plant. The final design proved to have significant benefits for Horsham as well.

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The operating principles of the Autothermal Thermophilic Aerobic Digestion (ATAD) process and its field of application with respect to the beneficial reuse of biosolids are explained with particular reference to the plant in use at the Bendigo Water Reclamation Plant.

The ATAD process is widely used in the USA and Europe for the stabilisation of biosolids. It is a thermophilic process operating in a temperature range of 50-70°C without external heat input, this provides for pathogen inactivation and volatile solids reduction sufficient to meet EPA guidelines for beneficial reuse. Advantages of the process include rapid treatment, stable process with minimal supervision, ability to accommodate widely varying loads, and a small land foot print. Downsides to the process include high energy use, need for odour collection and treatment and a moderately difficult sludge to dewater.

The plant in use at the Bendigo WRP is supplied with thickened sludge from DAF’s, employs a range of different aeration and mixing techniques, supplements aeration with pure oxygen and finally produces a 20% solids product using centrifuges. The plant is capable of meeting Victorian EPA Treatment Grade 1 (T1) specifications.

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Beginning in 2003 Goulburn Valley Water (GVW) undertook a project to select preferred online instrumentation, in an attempt to identify which analysers are the right equipment for the right application. From this project several analysers were chosen as a suitable equipment application for the online measurement of Turbidity, pH, Chlorine, EC, Streaming Current and Fluoride. In 2007 GVW concluded that there were too many choices of analyser, and a preferred list was decided on to reduce the selection to just two of each group of analyser. The following paper reviews a trial of four online analysers for the measurement of Fluoride at the Shepparton Water Treatment Plant.

From the trial, two meters were to be chosen as the best fit application for the preferred list. This paper also seeks out to answer the question on the need to have Total Ionic Strength Adjustment Buffer (TISAB) as an online reagent or not. The need for such a trial was highlighted as GVW at the time were undertaking tendering for three new fluoride dosing plants, and the selection of an analyser is critical to its operation. Overarching all of this process was the release of the new code of practice for fluoridation by the Department of Human Services, Victoria.

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