In the context of potable and pool water, effective disinfection is perhaps the most important thought, and the effects of poor disinfection can be felt by an entire community. In fact, water disinfection is a concept that dates back to 2,000 BC (granted, our technology has improved to this day). As such, the operator should have a keen understanding of how to measure the power of disinfection in water. Two options for assessing disinfection power include monitoring of free chlorine, and Oxidation Reduction Potential (ORP). The two measures are different, but how do they differ and what do the numbers actually tell us?

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In mid-2016, Aquatec Maxcon along with Royal HaskoningDHV commissioned Australia’s first full-scale aerobic granular sludge (Nereda®) WWTP. The plant has met all its effluent and recycled water licence requirements, but has been a significant learning curve for the operators with its 21st century technology and new instrumentation, maintenance, and testing requirements. This is an operator’s perspective of the Nereda® technology and everything else that enables the plant to run.

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At the Sandgate Sewage Treatment Plant (STP) a regular testing regime was established by operators for nutrient levels in the 3 Final Settling Tanks (FSTs) as well as Mixed Liquor Suspended Solids (MLSS), settleability and Sludge Volume Index (SVI) in the bioreactors. Regular operator sampling and analysis indicated rising ammonia (NH-3) and phosphorous (P) concentrations in the FST. This was an indication of under-aeration in the bioreactor. To help with early detection of similar events a Dissolved Oxygen (DO) check list was developed to compare results of the hand held DO probe and the infield DO probe. It was established that Bioreactor 2 had been under-aerating due to a false high infield DO reading.

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As the City of Logan’s largest wastewater pump station, the Alfred Street pump station at Slacks Creek has continuously provided wastewater transport services to the city for more than three decades. By 2010, the pump station had become inefficient, uneconomical to operate and posed safety risks to operators. These safety risks included operating high energy switchboards in the pump machinery hall close to pump motors, and maintaining three line shaft pumps in a dry well where the pump motors and supporting beams impeded access to the confined space and where using an overhead crane was difficult.

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Municipal wastewater treatment plants (MWTP) discharge large quantities of treated water to the environment each day that could instead be productively used to cultivate freshwater macroalgae. We have developed the use of freshwater macroalgae as an in-line secondary / tertiary treatment process integrating the intensive cultivation of Oedogonium intermedium with the treated discharge water from both a 29 ML.day-1 and a 1.6 ML.day-1 MWTP. In both cases the cultivation of Oedogonium resulted in large reductions in the concentration of total nitrogen and total phosphorous. The productivity of Oedogonium exceeded 50 Tonnes.Ha-1.yr-1 and this biomass was of high quality with a total protein content of 23%, making it attractive as a feed for livestock. This study demonstrates that the production of macroalgae can complement the operation of conventional wastewater treatment plants by recovering residual nutrients and simultaneously creating a high-quality biomass resource that is suitable for product development.

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The installation of an online Nutrient analyser in the Bioreactor at Edmonton WWTP has allowed the staff to optimise both the Alum dosing and Aeration systems and save significant amounts of chemicals, reduce electricity consumption while still maintaining plant process. To date the savings realised in chemicals are over $12,000 per year. Electricity savings are over $17,000 per year.

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Built in 1970, the Moura Water Treatment Plant (WTP) has had minor upgrades undertaken over the years, but with some of the outdated plant and equipment still in operation, it was becoming a major cost to Banana Shire Council for repairs and upkeep.
Applying for a government subsidy was the first step in the plant upgrade process and after obtaining approval 5 years ago, a 10 year plan was put in place, allowing the upgrades to be completed over 3 stages.

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The Wetalla Waste Water Reclamation Facility is owned and operated by the Toowoomba Regional Council. The facility is a Biological Nutrient Removal (BNR) process treating an Average Dry Weather Flow (ADWF) of 36 ML/D. The plant consists of two identical bioreactors operating in parallel. Bioreactor 1 was commissioned in 1995 while Bioreactor 2 was commissioned in 2006.

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The operating principles of today’s Wastewater Treatment Plants (WWTP) are permanently under review against world best practice. Not only does the right treatment selection play a vital role, but the energy efficiency is also of utmost importance with energy consumption a major cost factor during the lifetime cycle of installed equipment. It is no longer good enough to purchase individual components. Plant managers, design engineers and consultants must work together to find world best practice system solutions for today’s needs that flexibility cater for future requirements. With ever increasing energy costs, it is vital to understand the importance of the working principles of compressed air equipment, and its influence on the overall plant performance and lifecycle cost. Knowing that energy is the single highest operating cost in a WWTP, where blowers for aeration play a crucial role, knowledge of the different blower operating principles is important.

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Seqwater recently implemented a number of disinfection procedures for maintenance and project works. This project critically examined the disinfection procedure for filtration media which was based upon the AWWA standards B100 and C653. Sites that applied a single batch of highchlorine solution consistent with the AWWA Standard were unsuccessful in keeping chlorine residuals above the required 15 mg/L, even when the process was repeated with higher starting concentrations. The current study identified improvements to manage this issue and ensure timely reinstatement of the filter.

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Rain events that cause Inflow & Infiltration (I&I) have enormous impacts on the operation of wastewater networks and treatment plants. To meet our regulatory obligations and licensing requirements, a detailed analysis and modelling project of the Gold Coast Water & Waste (GCWW) operational network performance was implemented in a more focused direction. Whilst history tells us that the Gold Coast catchments will endure 2 to 3 high impact events per year, it is hard to put a monetary value on the true budget cost of these events.

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On the 12th of May, 2015, a sequence events began that, 10 days later, would culminate in a major hydraulic incident leaving the Yering Gorge pumping station critically damaged and exposing the operator on site to significant risk. This event would result in the station being out of operation for two months before partial pumping could be reinstated and a total of eight months before the station would again operate at its full capacity. The ultimate cost of this incident included approximately 10 Gigalitres of lost water harvest and a significant restoration operation costing over $1.2 million. This paper describes the events leading up to the incident, the investigation process and the key learnings identified.

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An important percentage of unrecorded flow in any water network is through larger water meters referred to as Commercial & Industrial (C&I) meters, or bulk water meters. This is due to the inability of some C&I or bulk meters to register low flow rates. While the amount of water measured through 20 mm domestic meters compared to that measured by larger bulk meters in the same fleet will vary from one council to another, it is almost always the case that the bulk users are some of the largest and highest value water customers of the council.

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Queensland Urban Utilities (QUU) has an extensive capital works program implemented to upgrade infrastructure at the Luggage Point Sewage Treatment Plant (STP). Luggage Point STP treats domestic and trade waste from approximately half the population of Brisbane, with a population of over 2.3 million people and growth rates forecast to rise. It is essential QUU, and stakeholders look at improving the Luggage Point STP process to cater to the population growth and ensure a sustainable solution is achieved for this catchment area.

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Design, installation and hydraulics of backflow prevention devices. Understanding the pressure drop and flow restrictions. Backflow prevention devices have become an integral part of the water supply asset. With the protection of the drinking water being paramount, backflow prevention is required by the Plumbing Code at any connection that is subject to being affected by a cross connection. The operation and subsequent restraints backflow prevention devices present is not well understood.

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Every time you fill a glass with water from the tap, prepare a meal, or take a bath, you take for granted that the water will always be clean, pure, and safe. Occasionally, situations occur outside of a council’s control that can jeopardise the quality of the drinking water. A very common occurrence in a local water network operating system is the temporary loss of pressure due to the breakage of a water supply pipe or water main.

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When the Sewerage and Water Supply Act 1949 (Qld) was amended in April 1992 it made way for Backflow prevention to be written into law in Queensland for the first time.

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Veolia is collaborating on research into water and waste treatment technologies, under a five-year Memorandum of Understanding with the University of Melbourne (MoU, 2015-2020). The first project focused on sites at Australia’s Casey Station, operated by the Australian Antarctic Division (AAD), in East Antarctica. This project aims to utilise low-energy biological processes, such as biofiltration, to treat summer melt water contaminated with diesel-based hydrocarbons.

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Obtaining a better understanding of the manner in which our sewer networks perform under differing conditions has been a long standing objective for Mackay Regional Council’s (MRC) water & sewerage team. After exploring a range of approaches and technology options, MRC focussed on partnering with a Sydney based Technology Company to develop a relatively low cost monitoring device that could be used in conjunction with an existing LPWAN communications network that MRC has already invested in for the use of Mi Water

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Unitywater conducted a trial in December 2016 designed to measure and define the mass of dry screenings captured per ML of treated wastewater at an Australian Sewage Treatment Plant (STP). The trial would be conducted at the inlet works of Maroochydore STP to determine the weight of screenings captured pre-screen and post screen. It is widely accepted that using an inlet works screen with a high Screen Capture Rate (SCR) and increasing removal of inorganic material reduces stress on downstream mechanical and biological processes. Unitywater wanted to conduct SCR trials on band screens, as they are widely accepted as having the highest SCR on market. The focus of the trials would be to quantify the capture rate of two band screen panel types at the Maroochydore STP and to quantify the dry kilograms of screenings per ML of wastewater. The technologies tested were a perforated plate Centre-Flo band screen and a new honeycomb panel Centre-Flo band screen. The data would also be compared to a third hooks and links style Centre-Flo band screen, also installed at the site.

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