Environment industries archive
Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.
Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.
In the semi-arid region surrounding Whyalla in South Australia, OneSteel has created a reed bed that provides an effective and efficient means to clean a waste effluent stream. The project will ultimately help conserve one of the most precious resources in the world’s driest country - water - and will improve the local environment.
The scarcity of water is an intrinsic part of life in most of Australia. Better use and conservation of this vital resource will improve the quality of life for many Australians, especially those who live and work in the semi-arid region surrounding Whyalla in South Australia, where OneSteel's Whyalla Steelworks has been operating since 1964.
Water is essential to the operations of a steelworks, being used for cooling, cleaning, lubrication and numerous other purposes. In Whyalla it is a scarce and expensive resource. OneSteel is keen to reduce water consumption and is also aware of the need to efficiently treat waste effluent before it is discharged.
Studies over a number of years have looked into the Steelworks' waste water discharges into the Spencer Gulf. The studies have identified the effluent from coke ovens as a significant source of organic matter and ammonia. OneSteel needed to reduce and/or eliminate these materials from its waste water prior to discharging it.
Within Whyalla Steelworks, the soil-based reed bed technology was first identified by a Superintendent of the coke ovens, while visiting British Steel's operations at its Llanwern Plant in the UK. The reed bed technology used at British Steel was founded in Germany by Professor Reinhold Kickuth during the 1960s. In Australia, reed beds have been used for stormwater run-off and sewage treatment, but little is known about other uses. The Llanwern plant represented the first reed bed technology trial on coke ovens effluent.
In soil-based reed bed systems, the effluent to be treated percolates through the biologically active soil and roots of a large bed of reeds and then drains through a pipe at the base of the bed. The function of the reeds is to pump oxygen into the soil through the roots. Near the roots, there is an aerobic (oxygen-containing) zone and further away, there is an anaerobic (oxygen-free) zone. Thus, within the soil, a range of processes exist that allow the transformation of environmentally undesirable components of waste water.
Oceans-ESU Limited was hired to design and manage the trial and the subsequent full-scale system. Construction of the trial beds commenced in February 1993. Surveys of reeds in the surrounding areas were undertaken and information on reeds best suited to waste water treatment was reviewed. Accordingly, five reed varieties, all of Australian native species, were selected to make up the trial. Once the system was established the process of adapting the reeds to the effluent was started. The trial lasted 18 months and paved the way for the planning of the full-scale system
After the trials, a large scale (2 hectare) trial system was constructed. Commissioning commenced in 1997. This involved the adaptation of the plants and biological life within the system to pollutants in the wastewater. Ongoing work is occurring to increase the effluent load removed by the reed beds. Currently, in excess of 70% of the ammonia is removed from the treated coke ovens effluent, with removal of other organic and inorganic materials running at or above 90%.
Aerial view of reed beds and Whyalla Steelworks
Close-up of reed beds
OneSteel's Environment Policy states:
" It is OneSteel's policy to achieve a high standard of environmental care by complying with current legislation and seeking continuous improvement in performance by taking account of evolving scientific knowledge and community expectations"
This philosophy can be seen in action in the reed bed project.
Strong winds, dusty conditions, hot summers with high evaporation rates, salts within the soil and water, have all posed problems at various stages. These setbacks have gradually been overcome through modifications to the successful European design to suit Whyalla's environment. The results of the trial to date, to a large extent, reflect the effort which has been put into monitoring and managing the system.
Resources similar to those used for the reed bed construction in the UK have not always been easy to source in Australia, particularly those of good-quality land and clay. At the British Steel system site, the soil in the area was excavated, and ponds lined with the excavated soil. Suitable soil for the trial reed bed at Whyalla had to be identified through extensive soil sampling because of the high salinity in the area. Due to the shallow water table in the Whyalla works area, the trial beds had to be built up from ground level.
OneSteel Manufacturing Pty Ltd
Post office Box 21
Ph: 61 8 8640 4450
Fax: 61 8 8640 4774
Oceans-ESU Australia Pty Ltd
PO Box 10004
Adelaide SA 5000
Ph: 61 8 8645 9903
Fax: 61 8 8645 5770
Web site: www.oceans-australia.com
Date of implementation: 1993-1999
Date of further initiatives: Ongoing.
Case study originally prepared 1997 by the Business Council of Australia
Date last updated: May 2001.