2013 – 76th WIOA Victorian Water Industry Operations Conference & Exhibition

4 & 5 September, 2013 – Bendigo Exhibition Centre

Supported by: Victorian Regional Water Corporations represented in 2013 by Goulburn Valley Water and Goulburn Murray Water.
Prime sponsors: Automation Group, Acromet, Peerless Industrial Systems and Xylem.

The following papers are listed in order of the conference program

CHLORINE RESIDUAL MEASUREMENT IN CHLORAMINATED SYSTEMS Aaron Ward – Melbourne Water

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Melbourne Water operates two treatment plants that employ chloramination as the disinfection process. Chloramines are used due to the long distribution systems these plants service. Several improvement areas in these treatment plants were identified to enable greater control in the operation of the disinfection processes. One of these improvement areas was in the operational monitoring of monochloramine and free ammonia, in addition to chlorine (free and total) residuals.

As part of the investigation work, it was found that the indophenol method for measuring monochloramine residual was the most reliable method available and has since been adopted in the field. Extended use of this indophenol method has shown that samples are sometimes providing a monochloramine result that is greater than the DPD total chlorine result, and that the reaction time of the test can have a marked effect on the magnitude of the results. Although more investigation into these test interferences is required, the new testing regime is already providing distinct benefit to the plant operation.

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FINDING A SOLUTION TO THE McKENZIE HILL ODOUR ISSUE Sri Prasanna – Coliban Water

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The objective of the paper is to outline: the issues faced in finding a solution to the long standing odour issue at McKenzie Hill and discuss the influence of customer communications from the planning phase to the completion stage of the project. Residents living near a break pressure pit at McKenzie Hill experienced odour issues since early 2000. Various solutions that were trialled with varying but with limited levels of success were: direct Oxygen injection, Oxygen injection with U-tube dissolver and Calcium Nitrate dosing, installation of a bio-filter and a vent stack at the pit and dosing of Magnesium Hydroxide Liquid (MHL) into pump stations

The paper briefly outlines the various outcomes of the qualitative investigations that were undertaken to analyse the shortcomings of the previous solutions and quantitative analysis outcomes which highlighted the risks involved with the proposed solutions. It then discusses in detail how the issues identified as part of the investigations contributed towards moving to a design and construct project that enabled the final solution to evolve towards using a combination of Oxygen and Sulfox® (a proprietary odour control chemical) and positive influence of customer engagement and communication on this project.

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MANAGING RISK TO POTABLE WATER SUPPLY DURING RECYCLED WATER RESERVOIR REPLACEMENT WORKS Peter Murphy – Yarra Valley Water

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In April 2012 Yarra Valley Water commenced works to replace the 1 ML Mount Ridley Class A recycled water tank with a 12 ML tank to meet the increasing demands due to development in the Hume corridor and Epping North areas. Significant operational system changes were required to maintain potable and recycled water supply to these areas during construction. It was essential that risks were identified and assessed to ensure appropriate controls were in place to manage these risks. A decision was made to maintain supply to the recycled water network via a cross connection from the potable network. The key risks were identified as (a) cross contamination between the potable and recycled networks; and (b) continuity of supply to both networks. These risks were managed by a range of control measures resulting in the successful delivery of safe and reliable drinking water during the Class A recycled tank construction.

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THE FUTURE IS CLEAR – IMPROVED DATA COLLECTION FOR ROBUST FILTERED WATER TURBIDITY MONITORING Matthew Whitelaw – East Gippsland Water

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The Australian Drinking Water Guidelines (2011) state that, “where filtration alone is used to manage risks identified from Cryptosporidium and/or Giardia, the filtered water turbidity target should be ≤ 0.2 NTU, and should not exceed 0.5 NTU”. This has prompted East Gippsland Water to further develop continuous water treatment plant filter performance monitoring, to facilitate accurate monthly and annual in-house reporting. The Victorian Department of Health are currently reviewing the Safe Drinking Water Regulations (2005) and have flagged that operational reporting requirements may be introduced in the 2015 version. It is possible that the new regulations closely follow the current Australian Drinking Water Guidelines for filtered water turbidity, with a 0.2 NTU limit 95% of the time and a 0.5 NTU limit 100% of the time.

An initial review of East Gippsland Water’s filter performance during 2011, against these targets, uncovered many challenges regarding the collection and analysis of data. Several upgrades were made as a result of this initial investigation to allow simple but effective data collection and analysis. The main upgrade to the data collection process was the introduction of a one minute polling interval to SCADA Historian for both the raw water flow and the filtered water turbidity. This allowed a simple determination of whether or not the plant is in operation and therefore the relevance of the corresponding turbidity values. This was a simple and cost effective project that has allowed accurate analysis of filter performance.

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INCIDENT RESPONSE TO 2013 HARRIETVILLE BUSHFIRES Trent Newton & Jamie Rossato – North East Water

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For many Victorian water corporations Incident and Emergency response is now becoming a regular occurrence as we all endure and adapt to extreme climatic events, during the summer of 2013 North East Water (NEW) was challenged and tested yet again with a large bushfire in the upper reaches of the Ovens River Catchment. This particular fire was well publicised within the media as The Harrietville Fire. This paper outlines the importance of water corporations having strong emergency response plans and connections with emergency response agencies and other utility service providers.

GSA REPORT Susan Peisley – Government Skills Australia

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Government Skills Australia (GSA) is one of 11 industry skills councils funded by a department of the Federal Government – the Department of Industry, Innovation, Industry, Science, Research and tertiary education. The mandate of Australia’s Industry Skills Councils is to bring together industry, educators and governments and unite them on a common industry-led agenda for action on skills and workforce development.

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A GREEN WICKET AT THE ‘G’ – AN OVERVIEW OF THE MCG WATER RECYCLING FACILITY Daniel Haworth – Tenix

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The Yarra Park MCG Water Recycling Facility is a Class A water treatment facility built on the doorstep of the iconic Melbourne Cricket Ground. A unique project that will secure the long-term water needs of the Yarra Park reserve and surrounds as well as provide a sustainable water solution to the Melbourne Cricket Ground. Commissioned in October 2012 and now providing recycled water for nearly 12 months this overview of the facility aims to provide a valuable insight into some operational conditions encountered at this innovative and unique facility.

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WETALLA SOLAR HALL OPERATIONS – 5 YEARS ON James Coonon – Toowoomba Regional Council

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The Wetalla Solar halls were built as part of the plant upgrade that was commissioned in September 2006. They are designed to handle all the sludge produced from the site when the plant reaches maximum capacity of 33 ML/day.

Before the plant upgrade, the Wetalla Stage 4 plant was producing about 1500 tonnes per month which was transported to the Thiess reclamation site at Swan Bank. The biosolids processed from the aerobic digesters had about 12.5% solids concentration and were stored in a clam bottomed silo for loading into semi-trailers and transport from site for beneficial reuse.

The commissioning began well but eventually problems surfaced, not with the actual belt presses but with the associated processes. Over the last 5 years we have made several improvements on the initial design. While the system does run efficiently, there is still room for improvement, and lessons to be applied in the design of future developments.

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CASE HISTORY – GEOMEMBRANE & FLOATING COVER SYSTEM, SOUTH AUSTRALIA WATER CORPORATION, WATTLE PARK RESERVOIR Bob Cahill – Layfield Group

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As part of a water security review to address severe drought conditions, South Australia Water Corporation (Owner) identified the need for several essential infrastructure projects which included an upgrade to the Wattle Park potable water reservoir. The Wattle Park reservoir, with an 84 million litre (22 million gallon) capacity, required a new geomembrane liner and floating cover system. At prior storage and treatment reservoirs using normal levels of chlorination for a disinfectant, the Owner had experienced premature failures with certain liner and cover materials.

Based on the operational importance of the Wattle Park project, a new performance specification for the geomembrane and floating cover material was developed. Meeting this specification required a specially stabilized and formulated geomembrane. This paper addresses the technical review criteria for selecting a new geomembrane as well as a number of project challenges and techniques used by the contractor related to the installation of a new liner and floating cover.

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RESERVOIR CLEANING – 18 YEARS OF VACUUMING AND REFLECTING David Barry – Aqualift Pacific

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Drinking water storage tank cleaning is carried out to maintain water quality and to monitor the condition of the structure. Many water supply providers now use the diver vacuuming method to clean their tanks, rather than isolate the tank for days and place personnel into confined spaces with the traditional drain and sweep methods. However, few are aware of the actual ‘nuts and bolts’ of the process. This paper will discuss the equipment used, the hazards encountered, vacuuming methods employed, waste water disposal issues, and the inspection opportunities that are available. After 18 years of reflections (and vacuuming), the author has decided it is time to offer the water industry a ‘snap shot’ of how this established process can be carried out safely, efficiently and effectively, for both the water provider and the water consumer.

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AQUANTIFY: ENABLING EFFICIENT RECORDING AND REPORTING OF PLANT PERFORMANCE AND WATER QUALITY Catherine Huf – Wannon Water

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The water industry has lacked a system for recording plant performance data conducted and water quality sampled by Operators. Ten years ago Wannon Water and Goulburn Valley Water combined to address this issue, however the vendor was based overseas, the system was quite complex and the lack of sufficient resources by both water corporations meant the technology was outdated before the system was fully built. Fast forward to 2011 – Wannon Water and Goulburn Valley employed the services of a Victorian company to deliver a modern, industry specific system. In 2013, that system has arrived!

Aquantify has the user in mind at every step. With the Operator being the primary user, the aim was to make it as quick and easy as filling in a log sheet, but with so much more.

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ADVANCED PROCESS CONTROL AIDS OPERATIONS DECISION MAKING Geoff Lukin – Western Water

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At many plants design engineers provide operations and maintenance manuals, which specify an operating MLSS concentration. This concentration is mostly provided only for the design horizon, which in some cases can be between 20 and 30 years.

Significant growth can occur in a catchment over this period and as a result the operating MLSS at year 1 may need to be significantly lower than in year 20. Excess biomass can lead to a number of issues such as settleability problems, excess foaming and scum production and increased aeration demand (i.e. increased power costs).

At Sunbury operations staff have reverted to Solids Retention Time (SRT) as a means of managing MLSS (specifically the biomass inventory). This has been completed by adding an SRT calculator to the site SCADA output on the PLC.

Operations staff are undertaking a program of works to optimize the plant and have implemented a sampling plan in order to find the breakpoint SRT for ammonia breakthrough during different seasonal conditions. This paper explains the background to SRT based control and advantages of this control mechanism and the specific sampling and advantages to the Sunbury Recycled Water Plant (RWP).

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INNOVATIONS IN UV TECHNOLOGY AT THE EASTERN TREATMENT PLANT IN MELBOURNE, AUSTRALIA Alastair MacNab – Trojan Technologies

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The Eastern Treatment Plant (ETP) is located approximately 40 km southeast of the city of Melbourne, Australia. All flows entering the treatment facility receive secondary treatment via activated sludge. This plant, constructed in 1975, is the largest activated sludge wastewater treatment plant in Australia and treats approximately 40 percent of Melbourne’s sewage. The existing activated sludge secondary treatment plant was recently upgraded to an advanced tertiary treatment plant to significantly improve the discharge water quality. The secondary process was augmented by further treatment comprising of pre-ozone, biological media filtration, post-ozone, UV and chlorine. The UV facility, designed to provide a 4-log inactivation of Cryptosporidium, is based on an innovative UV reactor design and validation strategy which were key elements in the successful implementation of UV disinfection at the Eastern Treatment Plant.

The advanced tertiary upgrade will significantly improve the discharge quality of the facility, reducing its impact on the receiving marine environment and creating a high quality recycled water resource suitable for a broad range of non-potable applications. The pathogen reduction requirements to produce “fit-for-purpose” recycled water in accordance with current Australian recycled water regulation and guidance was based on a quantitative microbial risk assessment approach. Ozone disinfection was designed to provide 4-log virus and bacteria inactivation in addition to a minimum 0.6- log inactivation of protozoa. The UV system was designed to achieve 4-log inactivation of Cryptosporidium, and is the primary barrier to address protozoa risks to the recycled water product and associated protection of public health.

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INNOVATIVE USE OF AIR SCOURING – ODOUR CONTROL AND CLEANING RISING MAINS Gary Black – East Gippsland Water

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A long standing odour issue in the township of Johnsonville in East Gippsland, and the unsuccessful trial of chemical methods to control this odour, led to unrest amongst our customers and damage to our assets.

Monitoring levels of hydrogen sulphide (H2S) from the rising main leading to Johnsonville had shown unacceptable levels of the offensive (and dangerous) gas before, during and after a number of trials of ‘odour control’ systems. Using Odaloggers, average daily levels in selected manholes varied between 100 ppm and 200 ppm H2S. After the unsuccessful odour control trials East Gippsland Water (EGW) adopted an approach of cleaning the rising main as a method of controlling the H2S and subsequent odours. Using Air Scouring Technology and Sodium Hypochlorite disinfection this has been successful at this site reducing odour levels to well below 3 ppm H2S

At a second site, and in response to a very expensive (~$100,000) unblocking of the Bruthen to Johnsonville rising main, EGW investigations revealed the cause of the blockage to be a residual compound most likely resulting from the chemical dosing to this main. In response to this issue EGW utilised its Air Scouring Technology to clean this main where more traditional methods such as flushing, pumping and high pressure cleaning had failed. Following on from this success EGW has now implemented a proactive cleaning campaign for this asset involving air scouring specific sections once a pre-set discharge pressure trigger point has been breached at the Bruthen Pump Station.

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DIAGNOSIS AND RECTIFICATION OF CLASS A PLANT PERFORMANCE ISSUES Clint Vandepeer – Yarra Valley Water

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The Aurora Recycled Water Treatment Plant was commissioned in 2009 to provide sewage treatment services and Class A recycled water supply via third pipe to new developments in Melbourne’s northern suburbs. The plant includes a conventional activated sludge treatment followed by advanced treatment to Class A quality via ultra-filtration and disinfection with ultra-violet light and chlorination. The plant was built with a capacity of 2 ML/day and expanded to 4 ML/day in 2010 with installation of a second ultra-filtration skid.

In 2011, plant operators started experiencing membrane performance issues and found it increasingly difficult to meet recycled water demands. Investigation into plant performance issues commenced and included;
• membrane autopsy to identify membrane fouling
• undertaking of targeted cleaning regimes
• identification and elimination of potential sources of fouling contaminants
• review and revision of process control philosophy and PLC logic.

This investigation project provided valuable learning and experience for Yarra Valley Water’s operators and engineers in the potential pitfalls of membrane operations and the level of quality assurance required on highly automated PLC programming.

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CORROSION INDUCED FAILURE OF VERTICAL STRESSING BARS IN CONCRETE WATER RESERVOIRS Brad Dockrill – Vinsi Partners

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Two recent case studies are highlighted where the failure of vertical stressing bars in concrete reservoir walls was observed whilst undertaking structural risk assessments of water assets. Had these failures not been identified and rectified the consequences could have been catastrophic.

The two case studies show that, for many concrete reservoirs (of this type), it is more likely to be a case of when rather than if failure will occur. They also show that, using a co-operative approach, considered and proactive inspection and monitoring/repair regimes combined with sound engineering judgment, the risk of failure can be minimised to acceptable levels.

The case studies indicate reservoirs with vertical stressed bars without cementitious grout encapsulation are subject to failure due to stress corrosion cracking. Reservoirs designed with this feature and a sliding base (that is not freely sliding) required wall strengthening where bars failed. Remediation measures were developed including strengthening to allow the service life of the reservoirs to be extended by many decades whilst maintaining critical service delivery.

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HOW TO TRAIN YOUR CENTRIFUGE: AN EXERCISE IN PROCESS OPTIMISATION AND THE BENEFITS OF INTER-CORPORATION NETWORKING Jarrah Feather – East Gippsland Water

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In 2009, East Gippsland Water (EGW) made the long term water security decision to build a 20ML per day dissolved air flotation and filtration water treatment plant (WTP) to supply its largest customer base within the Bairnsdale and Lakes Entrance region.

Like all major projects, the construction and commissioning of the new WTP was not without its issues. The one that would prove to be the most difficult to solve, extremely frustrating and time consuming for operators, was the operation of the WTP’s washwater facilities, and in particular, the centrifuge. After many months and a great deal of expense in contractor call-outs, employee time and overtime attempting to maintain operation of the centrifuge, EGW contacted a neighbouring water corporation who had a very similar washwater system. They obligingly offered their time, experience and facilities which resulted in some significant findings and recommendations for potential improvements to assist with the operation of our centrifuge.

Following the visit, several of these findings and recommendations were trialled with greater than expected results. The current paper will describe our findings and experiences, so these learnings may assist other water corporations under similar circumstances.

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LIFTING THE LID ON FILTER COVERS Adrian Voogt – Goulburn Valley Water

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Covering Water Treatment Plant (WTP) filters generally presents some challenges with solutions typically drawn towards do nothing, various fabric covers or a carport style hard roof. But what if these solutions are not fit for purpose? Goulburn Valley Water’s (GVW) Pyalong WTP slow sand filters are GVW’s only slow sand filter type and these have been experiencing some performance issues contributed by sunlight generated algae growth. A permanent ridged cover is the obvious solution, but how do you get in to inspect filter operation and maintain the filter media. A series of sliding covers turned out to be the preferred answer.

The four filter beds are each 2.5m wide by 10m long resulting in a roof area of 10m x 10m over the four filters. One single cover was not the answer, so the option was to look at a best fit for this site. This sounds like an easy task but in theory this is not without some technical challenges. These include the difficulty of getting quotations without technical drawings, material to be used and consideration to a number of what if’s. A few conversations later and sketches transform from conventional shed arrangement fitted with rollers doors to roller doors mounted in a horizontal plane to the final version of a series of sliding panels on two levels engineered to allow staged access to the four filter beds.

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WHEN THE DUCKS CONTINUE TO LINE UP: DRINKING WATER QUALITY NEAR MISSES AND THE ISSUES THAT LEAD TO THEM David Sheehan – Department of Health Victoria

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Each year, under Victoria’s Safe Drinking Water Act 2003, notifications are made to the Department of Health on known or suspected contamination of drinking water that are the result of system failures. Following on from last year’s paper, When all the Ducks Line up: Case Studies on Hits and Very Near Misses, this paper presents two more case studies where system failures could have been prevented, as well as providing an overview of some of the common themes and issues that can lead to drinking water quality incidents.

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WATER FLUORIDATION PLANTS IN VICTORIA Helen Oates – Department of Health Victoria

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In March 2009, the Department of Health published the Code of practice for fluoridation of drinking water supplies (the code). The code supports the Health (fluoridation) Act 1973 by detailing the design and operation requirements for water fluoridation plants. The purpose of the document is to ensure the safe and effective addition of fluoride to drinking water supplies. Importantly, it recognises advances in technology and the risk management framework underpinning the Safe Drinking Water Act 2003. The timing of the release of the code coincided with a period of rapid construction of fluoridation plants across the state. This paper outlines experiences which will assist the water sector to continue to effectively deliver fluoridated drinking water.

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