Barwon Water has completed its research into the viability of Aquifer Storage and Recovery (ASR) options.
ASR is a method for storing underground where it is filtered by natural processes before being recovered for later use.
Barwon Water was among the first Victorian water businesses to examine the potential of ASR, although the process is used successfully interstate and overseas.
Water (excess surface water, stormwater or treated recycled water) is injected into an underground aquifer through a bore. Injected water is contained between solid layers of clay or rock where it can't seep away. Later, when needed, the water is extracted from the aquifer via another bore.
Typically the water would be injected during the winter periods when demand is low, and recovered again in summer as demand increases.
Potential benefits of ASR over traditional surface water storage (such as reservoirs) include:
The most significant benefit identified in the Geelong region was for the storage and re-use of high-quality recycled water produced by the Black Rock Recycled Water Plant (currently under construction).
Ultimately, this water could be used to supply the new "purple pipe" recycled water system for the Armstrong Creek growth corridor.
Our research program looked at three potential sites:
Note, the Upper Eastern View aquifer is different and separate to the Lower Eastern View aquifer used by the Anglesea Borefield.
Our research involved drilling a number of investigation bores at each site to determine if suitable aquifer material was present. At some sites we also carried out a pump-test to identify how easily water could be injected and recovered from the aquifer.
We also looked at a number of other sites to determine if smaller-scale stormwater capture and storage was possible for industrial and sporting facilities. Although expensive to implement, these options may prove viable in the future as development and technology advances.
Upper Eastern View aquifer, north of Anglesea
Investigations concluded that the ASR aquifer could potentially store large volumes of recycled water from the Black Rock Recycled Water Plant for use at Armstrong Creek and Torquay North as part of a "purple pipe" system.
Waurn Ponds aquifer, near Armstrong Creek
Investigations in this area failed to identify any aquifer material suitable for ASR use.
Batesford aquifer, west of Geelong
This site is adjacent to the Batesford quarry. Results indicated that this site could assist with the storage of recycled water for possible future "purple pipe" developments. Under this scenario, recycled water would be sourced from a water recycling facility built specifically for this area.
Our investigations have identified the potential of using ASR as an option for storing and using recycled or storm water in our region. A number of these options are dependent on the timing of future developments and demand for recycled or storm water.
Given Geelong's secure water supply, there are no immediate plans to implement an ASR project. However, our research has helped us to design water supply options for the future.