The Bolivar Waste Water Treatment Plant, South Australia's largest; processes 60% of metropolitan Adelaide's raw sewage. The SA Water sewage treatment plant pumps recycled water to the Adelaide Plains for use in irrigated agriculture and horticulture.
SA Water engaged Geofabrics to assist in the infrastructure upgrade - with the aim of delivering an additional 12 GL per year of recycled water for irrigation. Phase 2 was to construct recycled water storage infrastructure to the area north of the Gawler River, enabling a new major irrigation area to be built. The recycled water storage included two 200 megalitre earth bank storage ponds. The pond's storage capacity was designed to cater to future growth in the area, for at least the next twenty years.
The improved performance is largely due to the Dupont Elvaloy® technology, which enables protection against weathering and UV resistance, whilst allowing the PVC alloy to maintain it's flexibility.
Selecting a suitable cushion geotextile for the liner is as important as selecting a durable liner. The bidim® A64 cushion geotextile was selected specifically for its Needle-Free properties.
Needle punched geotextiles are manufactured by punching continuous filament polyester strands with hundreds of needles. These needles are so thin that they quite often snap off during the process. Geofabrics’ manufacturing plant in Albury, NSW can use a detector to identify and manually remove any needles which would inevitably puncture the liner it is specifically designed to cushion. T5 Trinet drainage net was included and chosen in the design to allow any leaks to pass into a sub-liner leak detection system and essentially allow any leaks to be identified and located.
Extensive product testing, product performance and AS 4020 approvals were all part of the decision-making process; and ultimately the bidim® A64 cushion geotextile was identified as the most suitable solution.
Geofabrics were able to deliver the products successfully and economically on time and in full, and with Australian manufacturing quality assurance (MQA).
The liner installation was carried out by Geotest. The liner was able to be prefabricated in their yard, undercover and out of the elements. Prefabrication is possible with Coolgaurd® Oasis due to the flexible nature of PVC-alloy. Its flexibility allowed it to be folded into panels and then further welded on-site without the risk of stress cracking. Prefabricating also significantly minimises time-on-site welding and less time on site means reduced risk with less time spent around earthmoving equipment.
The ponds are in full operation and supplying water to the surrounding community and agriculture operations. Should any damage occur during the pond operations and design life, the Coolguard® Oasis liner can be easily repaired due to its flexibility and weld-ability, which will remain for the life of the product. By using premium products like Coolguard® Oasis and Australian Made geotextiles, SA Water ensured that maintenance would be minimised throughout the life of the pond.
Geofabrics is the only geotextile manufacturer in Australia, with plants in Albury and Southern Queensland. We pride ourselves on providing the best service to customers across the country, whilst supporting the Australian economy through Australian manufacturing.