A combined effort from a number of suppliers has resulted in the successful operation of a water reclamation scheme at Echuca on the Murray River, North of Bendigo.
The local water authority, Coliban Water, signed a 25 year agreement with Earth Tech to deliver a water reclamation plant, water storage and pipelines that would meet the needs of the area – the Campaspe Water Reclamation Scheme.
With sustainability as the driver, stage one of the scheme has achieved 100% water reclamation ending wastewater discharge to Australia’s Murray River, which is stressed due to drought and pollutants. It also achieved 100% re-use of biosolids.
Local farmers can now access five million litres of high quality class B water a day. The recycled water contains levels of phosphorus and nitrogen nutrients that provide further environmental benefits and cost savings from reduced fertiliser use.
In October 2005, stage one of the scheme was awarded the Engineers Australia (Vic) Award for Environment and Sustainability. The award was judged by a panel of engineers from Australia’s peak professional engineering association.
“The project is more than just a treatment plant,” said Kay White, Senior Engineer (Process Design) for Earth Tech.
“It replaced the existing plant and developed a treatment system that involves biogas reuse and reduces greenhouse gases.”
CST Wastewater Solutions (then called Contra-Shear Technology) supplied the rotary fine screens that remove solids from the raw industrial and sewage wastewater.
“Our screens were used because they could get the fine removal solids down to 500 microns, which was an important pre-treatment step to ensure minimal fibre and solids passing into the anaerobic reactors,” said Michael Bambridge, Managing Director of CST Wastewater Solutions.
CST Wastewater Solutions’ partner Global Water Engineering (GWE) supplied and installed the anaerobic plant coupled with biogas reuse.
According to the Naiad knowledge base of the Sustainable Water Sources Programme, the reclamation plant treats mixed wastewater containing high organic loads from industry.
To cope with this high-strength influent, the plant uses upflow anaerobic sludge blanket (UASB) treatment, followed by extended aeration and sand filtration. The reclaimed water is disinfected using chlorine gas.
The reclaimed water is stored in two lined lagoons, from where it is delivered to farmers via a new distribution pipe network.
The recycled water, which complies with Victorian Government guidelines, is mixed with existing channel water to achieve a salinity level suitable for irrigation.
Commenting on the biogas reuse, Kay White said: “The UASB reduces organic matter, converting it to carbon dioxide, water and methane. The methane is burned to heat the UASB.”
The UASB is used only in the peak season, when the influent carries the biggest load. “In Echuca, the annual tomato harvest, which lasts six weeks, produces a heavy organic load, so the wastewater requires full treatment. At other times, the UASB can be switched off when not needed,” she said.
According to Bambridge Michael, “Anaerobic treatment of suitable wastewater streams has several main advantages, including low sludge production, a small footprint and being a net producer of energy instead of a large consumer.”
CST Wastewater Solutions, with their partner Global Water Engineering, have a range of anaerobic reactors and processes specifically tailored to treat wastewaters.
GWE have about 175 plants operating in more than 30 countries, including Golden Circle Cannery, Visy Paper and the Campaspe Water Reclamation Scheme in Australia.
CST Wastewater Solutions (formerly Contra Shear Technology) have been providing a broad range of industrial and municipal water and wastewater solutions for 25 years.
CST Wastewater Solutions (formerly Contra Shear Technology) are suppliers of innovative wastewater treatment solutions throughout Australia and New Zealand, with projects also completed in Europe, Asia, Africa and America.
CST Wastewater Solutions are members of the Global Water and Energy Alliance, a group of select companies around the work committed to providing solutions in waste and wastewater treatment for the recovery of green energy and water.
CST Wastewater Solutions’ robust network of partners includes Smith and Loveless, one of the well-known water and wastewater pumping and treatment organisations, and Berson UV-techniek, innovators in UV disinfection for water reuse.
CST Wastewater Solutions’ broad range of 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; Lime handling; and silo systems; Continuous sand filters; Microfilters and screens; Solar-powered circulation; UV disinfection; Ozone treatment; Anaerobic treatment.
CST Wastewater Solutions also provide assistance with equipment and system selection, design, installation and maintenance, as well as operation of wastewater treatment systems and delivery of complete packaged plants.