From Drought to FloodCST Manages Water in Australia's Harshest Conditions

Tooleybuc's cost-effective ultrafiltration system, top and floods in the Northern Rivers Districts, below
Tooleybuc's cost-effective ultrafiltration system, top and floods in the Northern Rivers Districts, below

Dorothea Mackellar summed up Australia's climate beautifully with the opening lines of My Country: "I love a sunburnt country, A land of sweeping plains, Of ragged mountain ranges, Of droughts and flooding rains." And one company that know these climactic extremes to be true is CST Wastewater Solutions, whose advanced technologies are helping to drought-proof communities and at the same time protect them against the impacts of flooding.

In the first case study, Wakool Shire Council was concerned about the declining quality and quantity water resources, especially during times of drought or dry weather. They decided to install a CST ultrafiltration system in their plant at Tooleybuc, which not only improved the quality of water, but also required less maintenance than the old plant.

In the second case study, Richmond Valley Council upgraded to a finer screening at their Sewage Treatment Plant, which reduces blockages and allows for a more efficient treatment with less ongoing maintenance. It was a fortuitous upgrade for Richmond Valley, which received an intense storm just days after the project was completed.

The following text is a detailed account of each case study.

Drought Challenge: Tooleybuc NSW

Municipal councils all over Australasia are seeking optimum ways to address challenges posed by water resources declining both in quantity and quality under pressure from local populations and the needs of industrial and agricultural users.

Hazardous material screened out by CST technology
Hazardous material screened out by CST technology

Such demands are compounded further as environmentally and healthaware public authorities simultaneously seek to deliver quality water services while playing their part in conservation by making best use of their areas' shared water resources.

One council that has successfully used advanced ultrafiltration technology to deliver a high standard outcome for its district is Wakool Shire Council, which draws its water from the Murray River and treats it in the small town of Tooleybuc, NSW, right on the border with Victoria.

Working together with CST Wastewater Solutions' delivery partner Envirotech Water Solutions, Wakool Shire Council replaced the old plant with a new ultrafiltration plant to provide potable water for Tooleybuc's town water supply. The entire plant was installed in just two weeks of on-site work and achieved results exceeding Australian standards.

"It was an outstanding outcome to be able to work with the council to complete the work so efficiently within a narrow time frame. Wakool Shire Council is very happy with the installation, which uses technology widely applicable to the many councils facing similar issues," said Mr Damien Abbott , Business Development Manager - Victoria, CST Wastewater Solutions.

CST's SFC Screen Extractor
CST's SFC Screen Extractor

"Another big advantage for councils like Wakool is that on-site attendance and maintenance is very low, with only one day a week being required. This produces both cost-efficiency and OH&S benefits," continued Mr Abbott .

The new plant has a capacity of 0.5 MLD (over 20 hours) with a peak flow of 6 L/s. The water is treated for turbidity, colour, protozoa and viruses using CST's advanced ultrafiltration technology. The technology reduces turbidity from 8 NTU to <0.1 NTU, and colour from 15 to 5. Australian drinking water standards specify that acceptable drinking water needs to be <5 NTU and <15 true colour *, so the Tooleybuc plant well exceeds these standards.

"Improving turbidity by over 80 times and significantly reducing the colour to exceed Australian Standards is an excellent result for the project, which is widely applicable to councils and municipalities across Australia," said Mr Abbott.

The Pentair X-Flow ultrafiltration plant installed at Tooleybuc is a new generation of low-pressure membrane filtration technology engineered to produce water from all kinds of water sources using ultrafiltration (UF) and, more recently, nanofiltrati on (NF). X-flow's strength is the integration of critical process steps to ensure a Full Circle Membrane Technology partnering approach encompassing all key process and operational steps including membrane manufacture, engineering design, installation and commissioning support and ongoing operational support. CST integrates a range of X-flow and other membrane systems that are tailored to the specific raw water quality requirements and treated water objectives for clients.

Flood Challenge: Richmond Valley, NSW

An upgrade by Richmond Valley Council of its Casino Sewage Treatment plant has paid immediate dividends by withstanding the fury of June's storms and floods without suffering any polluting spills or odours.

The turnkey upgrade - which included retrofitting of fine screening technology by CST Wastewater Solutions - was completed just days before the bad weather along Australia's East Coast dumped more than 160mm of water on the council region within 48 hours.

"The Council couldn't have timed the upgrade any better. Their foresight and technology upgrade was perfect," said CST Wastewater Solutions Managing Director Mr Michael Bambridge. "The Northern Rivers District of NSW is one of the most flood-prone areas outside of the tropics, where events like this are likely to occur and reoccur, so the investment in new technologies has already paid off ."

The retrofit project - of a type that is applicable to councils and industrial uses throughout Australia and New Zealand - replaces the previous coarse raked screen design with current fine screening technology. This captures more solids to reduce potential blockages in tanks and downstream equipment, while reducing odours by sealing the inlet works and by the installation of new odour control units.

The project's high-efficiency fine screening SFC technology (Screen Press for Channel Installation) is engineered to deliver low-maintenance performance with reduced WHS hazards for municipal and industrial waste water operators.

The SFC allows for a much finer level of screening - 5mm compared with typical old systems at 60mm or more - which has led to a significant reduction in solids in the tanks, while producing more efficient treatment with less maintenance.

The retrofit also involved the installation of an SDS 20 compactor with two inlets - one for each screen - to dewater screenings to 25-30% dry solids. Each screen has an enhanced design capacity of 250L/s fl ow, providing a total capacity of 500L/s.

Technology transplant

The original inlet works at Casino STP were designed with a coarse manual raked bar screen system. The functional components of the treatment process downstream of the bar screen receive a high amount of debris, which formerly impacted the efficiency of the treatment process. The original inlet area also received a high amount of odorous gases, which previously contributed significantly to odours emanating from the treatment plant.

In addition to minimising these issues, the upgrade project involved fitting new technology into an existing layout, including tailoring the screens to fit into the existing formed channel.

The SFC technology involved in the retrofit - designed to lower investment, operational and maintenance costs in screening of municipal and industrial waste water with compacting of extracted solids - has also cut the amount of maintenance and waste that has to be handled by plant operators, reducing operational health hazards and improving OHS performance.

The same benefits are widely applicable to other industry and municipal applications, said Mr Bambridge.

The technology is also suitable for applications such as food and beverage, manufacturing and processing, mining, energy and resources camps where its low maintenance and high hygiene qualities are appreciated, agribusiness, and remote installations where low maintenance and high efficiency are priorities for users who do not need to have specialist staff constantly available.

"Not only are the tanks clearer and more efficient now, but the screen extractor also operates on level control and is fully automated, eliminating the previous labour-intensive operator handling of screenings," he said.

The robust and proven extractor is constructed from AISI 304 or 316 stainless steel without the need for hanger, intermediate or bottom bearings. Featuring a space-efficient design suited to small sewage plants, the standard unit can handle up to 1000m3 an hour with custom engineering also available for particular installations. A vertical version is also available to easily retrofit into existing pump stations with depths up to 8m, the screen allows removal of material before pumping, says Mr Bambridge.

The versatile SFC Screen Extractor can be installed in a channel or supplied with self-supporting tank, complete with inlet and outlet flange and optional bypass screen. WWA

* Based on Australian Drinking Water Guidelines Version 2.0 (Updated December 2013)

CST Wastewater Solutions

CST Wastewater Solutions

About CST Wastewater Solutions

CST Wastewater Solutions is a supplier of innovative wastewater treatment solutions throughout Australia and New Zealand, with projects also completed in Europe, Asia, Africa and America. The company is a member of the Global Water and Energy Alliance, a group of select companies around the world committed to providing solutions in waste and wastewater treatment for the recovery of green energy and water. CST Wastewater Solutions is also a member of the Australian Water Association (AWA), which promotes the responsible management of water and its related resources.

The company's robust network of partners includes Smith & Loveless, one of the world's most respected water and wastewater pumping and treatment organisations.

CST Wastewater Solutions' broad range of proprietary wastewater treatment equipment - which is manufactured to ISO9001 and EEC standards of safety and design - includes: Water and wastewater screening; Grit removal and dewatering; Septic receival stations; Dissolved air flotation; Sedimentation systems and clarifiers; Shaftless conveyors; Sludge dewatering; silo systems; Continuous sand filters; Microfilters and screens; UV disinfection; Anaerobic treatment.

The company also provides expert assistance with equipment and system selection, design, installation and maintenance, as well as operation of wastewater treatment systems and delivery of complete packaged plants.

CST Wastewater Technology packages

New engineer-and-build water and wastewater treatment and recycling packages from CST Wastewater Solutions are aimed at industries and municipalities that want to lower the cost and complexity of such projects. The design, supply and install packages - incorporating global and locally manufactured technologies proven in use by some of Australia and New Zealand's leading companies and councils - are aimed particularly at:

  • Councils seeking engineering assistance to develop clear choices and optimum solutions incorporating advanced low maintenance technologies providing high levels of water purity while reducing maintenance, waste handling and OH&S issues associated with running them.
  • Industries seeking readily constructed or portable, low maintenance solutions for operations particularly in remote, ecologically or environmentally sensitive areas - ranging from resources or agribusiness developments in the country or outback, through to food, beverage, manufacturing and processing plants sharing precious water resources with urban areas.

Rather than presenting such organisations with a jigsaw of disparate collections of technologies and engineering services options for them to piece together, the packaged solutions focus on clear, properly engineered solutions that deliver what they promise. CST offers turnkey solutions based on a known raw water quality and guaranteeing water quality outcomes thus giving user engineers significant confidence in the outcomes and limiting their exposure and potential concerns, says Mr Bambridge.

About the Author

CST Wastewater Solutions Managing Director Michael BambridgeCST Wastewater Solutions Managing Director Michael Bambridge has been a leader in wastewater and green energy solutions for decades. His company, established over 30 years ago, focuses on providing customtailored and cost-effective solutions to complex water and wastewater issues. Mr Bambridge's strong client focus, experience and fl exibility has ensured that CST remains one of the most respected names in wastewater management throughout Australia and globally. He believes that there is no 'one size fits all' solution, and that each project should be carefully considered individually to find the right engineering solution.