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.

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Wastewater from North Nowra is transported across the 400 metre long Shoalhaven River Bridge via a 300mm AC surcharge main, suspended under the bridge with Gibault joints. Due to hot weather and up to 70mm movement of the bridge deck, a minor leak occurred at the expansion joint and first Gibault joint at the northern abutment. Repair work was carried out at night to avoid peak flows and allow transport of wastewater by tankers. Emergency repairs were affected after contacting EPA, oyster growers, adjacent residents and media. The bridge crossing was drained down twice more to complete permanent repairs.

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Council previously determined that the Sherwood Road precinct was in need of a sewerage system. Extensive investigations revealed the suitability of a zero effluent scheme and the need to address a significant stormwater problem. Many of the properties in the precinct were discharging stormwater and greywater (failing septic systems) to the lower adjacent properties. These issues were accentuated by road drainage passing through the properties.

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Lawrence was the first Clarence Valley Council (CVC) scheme using a pressure sewer system. This paper outlines “lessons learned” from the Lawrence project, with a focus on planning and administrative issues rather than technical or operational outcomes. Key lessons were to ensure clear definition of scheme boundaries, involve pump manufacturers throughout the whole project from design to commissioning, create a central database for administrative ease, and ensure adequate community consultation throughout the project.

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Over the warmest summer months, algae grows in the balance tank at Woolgoolga WRP, creating a multitude of problems, including pH, TSS, increased sludge production, increased CO2 usage to aid pH correction, fouling of reuse filters, resulting in increased backwashing frequency and power usage. Barley straw has been previously used to control algae in sewage tertiary ponds in Central Queensland. As the barley straw breaks down, it releases an enzyme, which in the presence of dissolved oxygen can control certain algae.

Limited trials were conducted at Woolgoolga during the summer of 2008/09. In November 2009, following the success of these trials, ten bales of barley straw were placed in mesh bags and secured in the balance tank, costing a total of $200.

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Compliance management within the water industry should not be seen as a destination such as “we comply!”, but rather as a journey of improvement. This involves not only solving specific problems that have been identified, but also initiating a process of engagement at many levels.

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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. 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.

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Sludge management at Woolgoolga Water Reclamation Plant has been greatly assisted by the recent introduction of low energy aeration with probiotics into the existing sludge management system. The existing sludge management system was nearing capacity, with drying beds in continuous use and sludge lagoons constantly full. Low energy aeration was installed on Sludge Lagoon 1, which is fed with waste activated sludge.

Probiotics are also added to this lagoon at a rate of 4 L/day. The supernatant and a small amount of sludge overtops into Sludge Lagoon 2, with all sludge carryover being contained in the second lagoon. Since the introduction of the low energy aeration with probiotics, the sludge production has been greatly reduced and the sludge dewaters more rapidly, resulting in only one sludge lagoon being full while the other is almost empty. This system has greatly eased the sludge management at Woolgoolga, resulting in reduced sludge production, eliminated recirculation of sludge, and has ultimately saved a considerable amount of money.

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Design and configuration of water storage reservoirs has in the past predominantly been focused on personnel safety, with very little consideration given to the quality of the water. As these reservoirs approach their half-life many require upgrades to their access areas, internal structures and pipework.

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Mechanical agitators are used in various applications within a wastewater treatment plant, including in Anoxic/Anaerobic/De-nitrification Mixing Tanks, Sludge Mixing Tanks and Equalization/Neutralization Tanks. However in many instances, the presence of fibrous solids leads to an entangled “rag build-up” on the impeller which, over time, results in both mechanical and electrical overload leading to possible failure of the machine if adequate removal of the rag build-up is not maintained.

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The technologies used to measure the level in pumping stations (both potable water and sewage) have been traditionally hydrostatic pressure, ultrasonic, or simply switching (on/off) sensors. You may also add to these radar, which is fast becoming a preferred solution to many water and wastewater authorities.

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A blending evaluation is a planning tool that can be particularly helpful when considering introducing new or additional source waters to a water system. A blending evaluation is a systematic approach to addressing the likely water quality impacts of changing source waters and if necessary, potential mitigation approaches. North American case studies and a blending methodology that could be applied by any water system to plan for and mitigate a wide range of potential water quality issues.

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Having worked at the Bathurst Wastewater Plant for the past 28 years I have seen and worked on quite a few changes at the plant during this time. The plant has a long history having first been commissioned in 1916. In 1975, major changes were made and the “Bathurst Box” wastewater treatment process was born. Many more process updates have been completed since then and the plant now performs extremely well. This presentation is one “old” operator’s recollection of the evolution of the plant and processes and some things that have happened along the way.

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Objective – to safeguard workers and customers from electrical hazards arising when work is carried out on the water supply system to prevent: eletrocution of a maintenance employee and recently plumber at Yennora in March 2009; increasing incidence of electricity reported in water pipes (shocks and near misses).

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Regulators require recycled water treatment processes to be validated to ensure they meet the water quality requirements for the intended water use. Validation will often require challenge testing of processes such as membrane filtration and UV disinfection to demonstrate the ability of the process to remove specific target organisms.

Challenge testing is expected to confirm the maximum removal credit that a process is eligible to receive from the appropriate regulatory body. This is achieved by dosing challenge organisms into the feed of a process and measuring their removal by testing the feed and product water. The USEPA has published a Membrane Filtration Guidance Manual (2005) and an Ultraviolet Disinfection Guidance Manual (2006). These manuals are commonly used by Australian regulators to set conditions for validation and challenge testing.

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2010 will see much activity occurring in vocational education and training across the water industry.

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The presence of manganese often results in consumer complaints associated with black particulates that cause staining and generally lowers public perception of water quality. Waimakariri District Council (NZ) encountered such problems when a new source was developed for the Woodend Water Supply. A biological filter was chosen in preference to conventional physico-chemical treatment processes that have been traditionally used for manganese removal.

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