Albany Wastewater Treatment Plant
Reports
 | 2007 Triennial Report |
| | 2007 Appendix A - Soil Analysis Report |
| | 2007 Appendix B - Forestry Report |
| | 2007 Appendix C - Flow and Solute Model |
| | 2007 Appendix D - Groundwater Bore Data |
| | 2007 Appendix E - Soil Moisture Data |
| | 2007 Appendix F - Site Photographs |
| | 2006 Annual Report |
| | 2005 Annual Report |
| | 2004 Triennial Report |
| | 2004 Triennial Report plus appendices |
| | 2003 Annual Report |
| | 2002 Annual Report |
History
For years, treated wastewater was discharged into King George Sound, a practice that ended early in 1995, with effluent redirected to the new land-based disposal site.
The treated wastewater is used to trickle irrigate 450 thousand 'heavy-drinking' Tasmanian blue gums in the plantation.
The Tasmanian blue gums were chosen specifically because of their ability to 'drink' large amounts of water.
The first trees, established in 1993, have reached maturity and are now more than 19 metres tall.
About 50 hectares per year will be harvested for export as woodchips that will be processed at the new woodchip mill only a few kilometres from the plantation.
The potential return from the sale of woodchips makes the land based wastewater reuse option economically viable in the long term.
The decision to examine alternative methods of disposal was prompted by concern about undesirable changes in the protected waters of Princess Royal Harbour and Oyster Harbour due to the increased impacts of industrial discharge, stormwater runoff and treated wastewater discharge.
Community attention was focussed on the delicate environmental balance that existed as a result of urban and rural development around the harbours.
An exhaustive, four-year study and investigation into disposal methods was accompanied by close community consultation, with the community giving the land disposal scheme quite extraordinary support - so much so that people were prepared to pay higher sewerage rates to enable the scheme to go ahead.
As well as the development of the plantation site, the project involved the construction of new rising mains, main sewers, a main pumping station and the upgrade of an existing treatment plant.
An additional 120 hectares have been planted with the same fast-growing eucalypt.
These trees are rain-fed and have been planted downstream of the irrigated plantation to intercept any runoff.
Treatment Process
Most nutrients are retained on-site, with about half of the nitrogen being removed by allowing the wastewater to flood irrigate 14 hectares of pasture land, and the remainder being used by the trees.
Phosphorus is captured by the clay soils of the site, which were especially selected for their capacity to absorb large quantities of phosphate.
When it is too wet to irrigate the plantation, wastewater is stored in a large dam on site.
The stored wastewater is applied to the trees mainly in the summer or when soil moisture content is low enough to allow irrigation.
The irrigation scheme is computer-controlled, with soil probes continuously monitoring the soil to prevent over-watering.
Every day, about 4,500 kilolitres of treated wastewater is pumped from Albany to the land disposal site.
Most of the plantation, some 300 hectares, is irrigated by trickle irrigation.
The land treatment system - the first full agro-forestry scheme for wastewater disposal in Western Australia - establishes the Albany project as the pacesetter in wastewater reuse in Western Australia.
An average 250 million litres per day is collected by the wastewater system throughout the State, with currently only some two percent being reused.
The Western Australian community clearly regards treated wastewater as a valuable resource, and the Water Corporation agrees.
The Future
Currently under construction at the Albany Tree Farm site is an exciting expansion of the environmentally sound wastewater disposal offered by the site.
In a joint venture with the City of Albany, The Water Corporation is establishing a state of the art septage treatment and disposal facility for complete integration with the tree farm irrigation systems.
This offers the best possible environmental solution to septage treatment in Albany, which was previously disposed of into an unlined and open pit.
There is considerable ongoing research at the Albany Tree farm.
The University of Western Australia has been heavily involved in studying nutrient cycling under the irrigated plantation.
The Ecosystems Research Group at UWA has investigated the water and nutrient use of the plantation and assessed the condition of irrigated trees and soils compared to non-irrigated.
This world-class research will allow optimisation of the disposal of treated effluent to blue-gum plantations.
Edith Cowan University has been investigating the changes in microbial population structure beneath the irrigated plantation.
This research will describe dynamics of the microbial communities responsible for the soil nutrient processes under the plantation.
An arboretum was established in 1995 to allow study of the performance of tree species other than the fast-growing blue-gum.
These trees are being assessed for viability as an effluent irrigated tree and whether there is potential to generate higher value sawlog timbers in an irrigated plantation.
In conjunction with The Department of Agriculture, the Water Corporation is investigating the viability of irrigating a WA native tea-tree species, Agonis fragrans, for the production of aromatic and medicinal oils.
A crop such as this is better suited to small, remote wastewater reuse systems owing to the higher crop value and lower relative freight costs.
Contact Us
For more information about our Albany operations call 08 9842 4252.
