Many plants suffer from poor DO control even though they have continuous DO monitoring and direct control of aerators to a preset DO level. Poor control is usually the result of problems with 3 or 4 aspects of the process of measurement and control. The overlap of these problems results in greater difficulty in isolating specific causes and effects. This paper focuses on data showing symptoms and identifies causes in addition to showing how various parameters such as ammonia and nitrate relate to the inlet BOD Kg load and the DO control system.

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Mt Beauty is a small town, which uses Ozone to disinfect water to a population of 2,700. Water quality is of a high standard not needing treatment before entering the Ozone Plant. The plant delivers between 1 and 3 Megalitres per day and is simple to operate requiring minimal time. The final water has no taste and odour problems but does appear white in colour, which creates public concern. Backwashing problems in the GAC filters have caused biological growth resulting in failures to comply to WHO standards. In this paper I will cover all the operating problems, and issues associated with Ozone/GAC as a final disinfectant.

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This paper presents a synopsis of the key operational issues at the Koorlong Wastewater Treatment Plant. The plant provides primary treatment of wastewater only and is designed to essentially remove solids through a chemically assisted sedimentation process. Whilst the treatment train at the plant is relatively simple, the high variability of the wastewater flows and composition complicates the operation of the plant. The disposal of effluent through drip irrigation and maintenance of the plantation pose other significant operational challenges.

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Grampians Water provides urban water and wastewater services to 74 towns in the west of Victoria. The town of Edenhope, with a population of around 800, is situated in the West Wimmera near the South Australian border.

Drought conditions have continued over recent years, and winter rainfall run-off has been insufficient to replenish the town’s normal source of water, Lake Wallace. The lake water levels are now at an unprecedented low level, and water salinity levels have risen to unacceptable levels. Supplementary groundwater supplies are available for emergency purposes, although this water source also has relatively high salinity.

Faced with diminishing water quality and quantity, an immediate need to implement a more suitable alternative water supply arrangement arose. The resulting action plan included the installation of a desalination facility suitable for dealing with the brackish groundwater.

The necessary works to install the alternative water supply and treatment works were successfully completed within a very tight timeframe. It is believed that this innovative solution to a unique problem is the first application of its type in Victoria.

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Polyaluminium coagulants are finding increasing use in potable water treatment plants throughout Australia, with polyaluminium chloride (PACl) in particular now having wide application. This paper reviews the properties and advantages of using these chemicals with particular reference to experience at Daylesford, the Grampians region, Swan Hill and Tidal River, all in Victoria.

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Mains cleaning programs are now common practice in the water industry to improve or maintain drinking water quality to meet business plan targets, guideline requirements and customer expectations. In addition to cleaning the mains, a carefully planned program provides the additional opportunity to collect important system asset information.

Western Water commenced a systematic mains cleaning program in year 2000 primarily using air scouring technique. The mains cleaning program compliments a wide range of treatment plant improvements completed over recent years. The program is also driven by Western Waters’ strategic plan to control taste and odours throughout the water supply system.

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Membrane bioreactors (MBRs) combine the use of biological processes and membrane technology to treat wastewater. Within one process unit, a high standard of treatment is achieved, replacing the conventional arrangement of aeration tank, settling tank and filtration that generally produces what is termed as a tertiary standard effluent. The dependence on disinfection is also reduced, since the membranes with pore openings, generally in the 0.1-0.5mm range, trap a significant proportion of pathogenic organisms. The more common MBR configuration is to have the membrane immersed in the wastewater, although a side stream configuration is also possible, with the wastewater pumped through the membrane module and then returned to the bioreactor. Operating at a mixed liquor suspended solids (MLSS) concentration of up to 20,000 mg/L and a sludge age of 30-60 days, MBRs offer additional advantages over conventional activated sludge plants, including a smaller footprint.

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This paper provides engineers and operators with helpful information for the identification and remediation of poor filter performance, based on experience gained by Gippsland Water in filter management. The following points are covered:

• The importance of well operated and maintained filters.
• Operator’s knowledge of filter performance.
• Observations from failures and their reasons.
• Rebuilds, modifications and simple remedies.
• Re-establishment of performance and ongoing monitoring.
• Performance monitoring tools.

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The “lynch pin” in any Treatment Facility is the Operator. “Ownership” of an operation is the key to the economical functioning of the plant. Ownership will only develop if the Operator is permitted to have meaningful input into all phases of the design processes. Management must allow the Operator to spend considerable time participating in all aspects of the design through the concept development, design review process, Hazops, construction and commissioning phases. The cost of this time can be returned in full over a very short operating period.

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The water treatment plant at Bacchus Marsh, operated by Western Water, supplies drinking water to the township at demands of up to 15 ML per day. The plant has recently encountered a number of operational problems, due to deteriorated raw water quality.

The plant is of pressure filter design and was formatted to treat reasonably good quality raw water. When the Turbidity and colour increased dramatically, the filter run times were reduced from 24 hrs to 2hrs maximum. At this point we looked at dosing Alum into a 40 Ml raw water storage basin sited at the plant, from which the filters draw. After some trials and tribulations it clarified the water beyond expectations and the pressure filters were pushing out .05 NTU water. As we expected the fairytale did not last. Taste and Odour problems were upon us. This paper works through initial control measures, the addition of Granular activated carbon to filters and raw water basin cleaning.

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Manganese exists naturally in some soils and enters into ground water or is washed down to surface water reservoirs. If not oxidised, manganese(II) ions will escape through water treatment processes into the supply system. Once in the system, the ion is gradually oxidised to insoluble manganic dioxide causing dirty water problems.

Manganese(II) can be oxidised to insoluble manganic dioxide and removed by clarification and filtration. Oxidation can be achieved by aeration, chlorination or chemical oxidation using potassium permanganate.

South Gippsland Region Water Authority (SGRWA) has manganese problems in most of their surface water reservoirs. This paper shares the experiences of SGRWA in removing manganese and compares the advantages and disadvantages of alternate oxidation methods with plant scale data.

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An optimisation programme was conducted at Sydney Water Winmalee Sewage Treatment Plant to determine the cost effective phosphorus removal in the sequenced batch reactors (SBR).

The different phosphorus removal mechanisms were evaluated and it was found that, simultaneous biological and chemical reactions were responsible for the phosphorus removal. The biological phosphorus removal represented the 32% whereas the chemical and adsorption mechanisms were represented by the 68% of the total phosphorus.

The addition of iron into the flow splitter reduced the SBR effluent phosphorus concentration from 1 mg/L to <0.5 mg/L and the 50 percentile final effluent total phosphorus was 0.1 mg/L, this was achieved with significant chemical cost reduction.

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Preliminary investigations into the upgrade of the Eildon Wastewater Management Facility have resulted in Goulburn Valley Water undertaking a ferric chloride trial on its trickling filter system. The trial aimed to determine the suitability of dosing ferric chloride, with the intention of reducing phosphorus levels to acceptable environmental limits for future discharge to waterways (ultimately the Goulburn River). The trial was conducted between December 2000 and April 2001. This paper aims to present the results of this trial.

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Gippsland Water has undertaken a review of water treatment plants and is modifying them to improve their performance in meeting World Health Organization quality parameters. A number of existing plants are very old and employ outdated technology, so where necessary, design and construction of new water treatment plants is also being considered and implemented.

Gippsland Water has opted to build a number of small package plants for communities where treated water production is less then three megalitres per day. Water treatment plants supplying water to larger areas including Moe, Warragul, Traralgon, and Morwell also required major extensions and refurbishment. In particular, the Warragul site posed a real problem in that it consisted of a 6m by 6m tin shed containing dosing pumps, chemical storage and instrumentation, a clarifier tank that was at least fifty years old and no filtration.

Clearly, modifications to the existing plant would not have been appropriate, so the Authority decided to construct a new plant. A Design and Construct tendering process was undertaken and a new Dissolved Air Flotation water treatment plant (DAF) was constructed. This is the first plant of this type in Gippsland Water’s region.

After commissioning, the plant performance was still well below Gippsland Water’s expectations and a number of process modifications were undertaken. This paper outlines some of these problem and the remedial actions undertaken.

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In this era of lean, performance focused Water authorities, efficient and broad access to system information, environmental, OHS and other relevant regulations, , and customer data is essential to monitor, operate and service customer needs efficiently. Staff in a multi-skilled environment also need access up to date information quickly and easily to respond and complete activities. Further, customers and regulators are requiring more information to be publicly available and easily accessible. Web based technology is an ideal means to delivery these needs both internally within the business and externally. This paper seeks to explore the opportunities and possible applications of Web based technology, which could benefit the operations side of the Water industry.

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