This paper highlights the modifications to the Hydrated Lime dosing system at the Bundamba Advanced Water Treatment Plant (BAWTP).

The original system was designed to be a two lime silo batching system, used to stabilise the 66 MLD of RO permeate. The high lime slurry batch concentration (a minimum of 4%) resulted in an unreliable and unstable dosing system, with frequent blockages, equipment failures, instrument failure and regular cleaning out of the Treated Water Tank’s feed well. Varying production rates amplified the systems shortcomings, as well as creating difficulty controlling chlorine and pH levels in the final product water. The plant design did not allow for a duty/standby configuration of critical equipment and the automatic flushing of the slurry dosing system after shutdown.

The physical of the original system created safety issues, such as trip hazards, manual handling problems and flexible dosing hose failure. After implementing pipework and control modifications, only one lime batching system is required for full plant production of 66 MLD.

The plant reliability and maintenance requirements are also improved with reducing slurry dosing pipe size from 50 mm to 25 mm dia., eliminating lime build up and blockages, trip hazards and manual handling problems. In addition, the batch concentration of the slurry can be reduced down to 1.5%, improving reliability of downstream instruments and final water quality.

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Ensuring that skills and training of staff are concurrent with ever changing legislations, codes and striving for continued improvements for industry best practice will always provide a challenge in any industry.

For North East Water, as with many other organisations, the challenge was compounded by having valued long term employees with experience gained over many years, in some cases over thirty years in the water industry.

The issue was to find methods of continually providing information, instruction and training that did not make staff feel they were being made to “suck eggs” and that was seen as a value added addition to their careers.

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The Innisfail Water Treatment Plant (WTP) is a conventional water treatment plant comprising chemical dosing, clarifiers, media filters, and disinfection before pumping to reservoirs and to the community.

The raw water is sourced from the Johnstone River and the raw water quality can vary, particularly in times of Rain events, Cyclones and flooding. Turbidities range from 2NTU in dry times and can increase up to ranges of 150, 300, 500 NTU and can last for a couple of weeks depending on the weather.

This puts extra strain on the treatment plant to continually provide good quality treated Potable water.

This paper covers the investigation into the use of a Streaming Current Detector on raw water that the plant draws from. It discusses the trial which confirmed the benefits of installing and outlines the cost savings in both chemical and labour resulting from this work.

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Bundaberg Regional Council (BRC) has established a Beneficial Use of Biosolids project where biosolids produced at BRC’s Wastewater Treatment Plants (WWTP) are used as a soil conditioner on agricultural land in the Bundaberg region. BRC has taken on all risks and responsibilities for the management of this project including biosolids analysis, soil analysis, calculation of application rates, spreading and incorporation of material into the soil and GPS tracking of application areas.

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The January 2011 Flood event devastated the Local Somerset Regional Council area. This led to a lot of rectification works that had to be done and along with these works, some flood resilience projects to be undertaken. The flood resilience work program was instigated by State Government to ensure that future events like 2011 have a reduced impact on drinking water production operations. Although Seqwater Water Treatment Operations as a whole performed reasonably well under such trying conditions, there was a need for improvement across the board.

The purpose of this paper is to create within the readers mind an insight into what we had as far as appropriate process technology available to us before and during 2011, and what was achieved with a lot work, time and money to prepare us for the subsequent 2013 flood event. Upgrades to the Lowood Water Treatment Plant after the 2011 floods resulted in the plant managing raw water turbidity levels in excess of 9,000 ntu. This contributed to Seqwater’s overall operational resilience in its ability to effectively manage extreme weather events.

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Water scarcity has become a growing issue globally. Many cities in the world are experiencing water stress, i.e., deterioration in water quality and growing shortage in water quantity. Reuse of treated municipal wastewater offers an attractive solution to the water stress problem. The treated wastewater can be reused for the purpose of irrigation, landscaping, toilet flushing, car washing, industrial use, etc. Since people are in direct or indirect contact with reuse wastewater, its proper disinfection is critical for protecting public health. Chlorine is used for disinfecting wastewater for reuse purposes, but there are two issues associated with chlorine disinfection. First, it has been well established in the literature that chlorine disinfection forms disinfection by-products, such as THMs, HAAs and NDMA. These by-products can cause both acute and long-term health effects. Second, chlorine is ineffective in disinfecting Cryptosporidium. In many parts of the world, Cryptosporidium is commonly found in municipal wastewater even after conventional treatment [1]. A Cryptosporidium outbreak in Milwaukee, USA, in 1993 affected 403,000 people.

Ultraviolet (UV) disinfection is effective in controlling a broad spectrum of pathogens including chlorine-resistant Cryptosporidium. It is also environmentally friendly in that no harmful by-products are formed. UV disinfection of wastewater for reuse purposes has been successfully applied for decades in large scale treatment plants in North America and recently on a global scale.

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Jimboomba and Flagstone wastewater treatment plants, located at Logan South, are maintained and operated by Logan City Council. Jimboomba wastewater treatment plant is an SBR type biological process. The sludge processing facility at Jimboomba wastewater treatment plant includes two sludge lagoons and portable rotary fan press. Flagstone wastewater treatment plant is an AAT/IOC type biological process. The sludge processing facility at Flagstone wastewater treatment plant includes one sludge lagoon and portable rotary fan press. The portable rotary fan press is used alternatively for two months in each plant. During 2011-12 financial year, 834 ML of wastewater was treated at Jimboomba wastewater treatment plant. At the same time, 1293 ML of wastewater was treated at Flagstone wastewater treatment plant.

This paper will discuss the process involved and the performance of the portable rotary fan press and analysis of dewatered sludge consisting of 12-13% of solids. The concentration of TN, NH3, and TP in dewatered sludge is 46000 mg/kg, 930 mg/kg and 70000 mg/kg respectively. Quantitative analysis of generated Biosolids, Operational experience, including advantages and disadvantages, on this dewatering facility will be presented in this paper.

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Wide Bay Institute of TAFE (WBIT) is currently investigating the viability of vocational placements for new water students in QLD as a way of opening study options for non-workers. The NWP07 Water Operations qualifications have been developed to support experienced industry practitioners and new entrants seeking to commence or develop a career within the water industry. The majority of learners participating in water operator and wastewater operator studies currently come from existing workforces of the water service providers in QLD and across Australia. This is due partly to the fact that not many registered training organisations have current and working water and wastewater treatment facilities on their campuses.

The potential issue with this approach and the recognition of an aging workforce means opportunities for new and younger operators remain very limited. Vocational placements for students may enhance workforce development strategies and succession planning in regional areas of QLD. This discussion will explain training packages, vocational placement in QLD, the difference between vocational placements and work experience students, and workforce development planning. WBIT intends to gauge the level of support from industry in this strategy through completion of a survey of participants.

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The purpose of this paper is to provide an insight to the plant operators, shire engineers, consultants and contractors to the water and wastewater and associated industries, of the many pitfalls and hazards associated with the supply and installation of incorrect materials by inexperienced contractors for chemical dispensing.

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Biomethane also known as biogas — is a hydrocarbon gas produced from the breakdown of organic matter in the absence of oxygen. Biomethane is generally produced by one of two methods:

Anaerobic digestion – biogas is produced in purpose-designed, above-ground tanks or in ponds to optimise the gas-producing decay process from human and other organic waste.

Landfill – biogas is produced by allowing natural decay to occur within a landfill site where gas is produced and then extracted.

The Petroleum and Gas (Production and Safety) Act 2004 and the Petroleum and Gas Regulation 2004 govern the safe operation and management of biomethane gas installations. Biomethane, including gas produced from waste disposal tips and treatment of sewage, is defined as petroleum and fuel gas under the Petroleum & Gas Act and the Regulation. As such treatment plant owners and operators must be aware of their responsibilities in accordance with the Act.

This paper describes the issues encountered by Allconnex Water/Gold Coast Water/Gold Coast City Council in our endeavours to comply with the Act and Regulation relative to the construction of a new digester at Coombabah Treatment Plant and the retrofitting of a 35-year-old digester at Elanora Treatment Plant.

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The Oxley Creek Sewage Treatment Plant (STP) was partially inundated in the January 2011 floods that occurred in South East Queensland as a result of excessive wet weather. The flood levels fully covered several parts of the STP, significantly compromising our ability to operate. The sewer network was also fully covered in areas. The aim of this paper is to capture conditions and recovery plans prior and post flood. Prior to flood event all the equipment was properly shut down and Energex was notified to isolate the energy feed.

Return Activated Sludge (RAS) from FST’s (Final Settling Tank) was returned to the bioreactors. This conserved the biomass allowing us to re- start the process after the flood. The flood water inundated the HV room, main inlet pump station, blowers, UV disinfection, and advanced biosolids treatment facility (Thermal Hydrolysis, Digesters, chemical dosing system and Centrifuges).

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Following on from the successful implementation of the Tasmanian Advisory Committee, a similar Advisory Committee was formed in 2011 to support the development of WIOA and all members in Queensland.

This committee was established at a meeting held at the SMEC offices in Brisbane in September 2011, where representatives from a wide cross section of the state were present and fully supported the implementation of a Queensland advisory committee.

Jason Krzciuk, who was employed with Seqwater at the time was appointed as the first Chairman of the Advisory Committee. He has since moved to Origin Energy. Marcus Boyd from Toowoomba Regional Council took over the role from Jason in September 2012 and is the current Chairperson. His term will conclude in September 2013 where the position will again be open for the next appointment. The only criteria to be on the Advisory Committee is to be a WIOA Member and be employed within Queensland.

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Damaged pipes are generally repaired by the traditional methods of ‘excavate and replace’. The benefits of non-invasive rehabilitation technologies, which apply to so many other aspects of society, are often overlooked.

Over time, pipe systems can develop problems, begin to fail and require attention. Replacing those pipes comes with the need to dig through roads and footpaths, which can be very time-consuming, costly and disruptive.

However, this can be avoided by using non-invasive technologies equivalent to angioplasty to clear pipes and install their version of a stent in order to rehabilitate failing lines and provide structural rehabilitation to weakened areas.

This paper evaluates the benefits of using non-invasive pipe lining technologies to repair damaged pipes and compares these methods to the “excavate and replace” methods traditionally used.

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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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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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This project aimed to investigate the most frequently utilised methods of estimating activated sludge settleability. The three methods investigated are the settled volume, dilute settled volume and stirred settled volume. Results from these tests can be used to adjust the wasting and return rates and can also give an indication of effluent turbidity. It was found that the SSVI method, outlined in the Standard Methods for the examination of water and Wastewater, produced the most consistent and least variable results of the three methods. Although the settled volume and dilute settled volume methods had significant variations, their usefulness in monitoring the wastewater treatment process should not be discounted.

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Nature strip congestion has become a serious problem within Wagga Wagga for Riverina Water County Council over the last decade. This congestion on the nature strip is primarily due to the numerous telecommunication carriers with an optic fibre network in the city, of which there are currently six. The result of this congestion is significantly increased construction times and costs being incurred by Riverina Water. A recent job to replace 550m of 450mm DICL pipe resulted in 6 months work and $80,000 expenditure to identify a suitable alignment on the nature strip. In the end, we were unable to construct on the nature strip & the pipeline was built under sporting fields.

These costs and a number of other incidences resulted in us posing the question “why we have no rights on the nature strip, when The Telecommunications Act 1997 gives telco’s the right to do whatever they want?” Water utilities have to work with the largest & least flexible material of all utilities on the nature strip, yet we are the ones with no rights when it comes to installing and maintaining our asset. With the NBN rollout having just started in Wagga, this situation is only going to get worse, going by our first experience with NBN Co.

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Computational fluid dynamics (CFD) has been used successfully to optimise the design of water storage tanks. Potently these techniques identify possible short-circuiting and eliminate storage dead zones within the tank, which is conducive to achieving required residence times. In many instances a CFD model has been utilised using qualitative methods to study flow patterns which has not translated to improvements in the field.

An innovative low cost CFD modelling technique that incorporates ‘passive scalars’ allows the designer to introduces a tracer to the CFD model which results in quantitative performance indicators such as baffle factors and Residence Time Distribution (RTD) curves. For large un-baffled tanks the commonly used characteristic contact time (t10) method may lead to misleading results regarding baffle factors. Alternative means of assessing tank performance and contact time will be discussed. In addition to confirming tank design, this new low cost CFD method is frequently used to model pump wet-wells, drop structures, energy dissipation structures, spillways and weirs.

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The enhanced biological phosphorus removal (bio-P) activated sludge process has a reputation for variable performance. The challenge with optimizing bio-P is that multiple factors influence process performance. One significant factor contributing to variability in bio-P was found to be related to microbial population dynamics involving the competitive growth of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs). It was found that the key factors in their competitive growth were the specific type of VFA in the influent to the bioreactor, and the pH and temperature in the bioreactor. The PAOs seem to have a competitive advantage to use propionate, whereas the GAOs have a competitive advantage to use acetate. Furthermore, PAOs have a competitive advantage at temperatures less than 20C and at alkaline pH values in the range of 7.5 to 8.0.

Therefore, in order to achieving reliable biological phosphorus removal it is necessary to control multiple factors within the optimum range, including providing an adequate supply of propionate, or an alternative substrate such as molasses that can be readily fermented to propionate. This paper consolidates experiences gained from many biological nutrient removal (BNR) plants including Noosa STP, in combination with supporting evidence from a literature review, to provide guidance to operators to optimize bio-P processes.

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