Water Journal : Water Journal June 2013
45 Ozwater Report could be implemented in the Docklands precinct, capable of saving up to 740 ML of drinking water per year. In the presentation, John Poon explained that, although the project did not have a positive net present value, it was an important rst step in setting up recycling for a major inner city development area. There is a nexus between groundwater, stormwater and recycling in the practice of groundwater replenishment with stormwater or high-quality treated ef uent. Vanessa Moscovis proudly laid out the story of the Water Corporation's successful Groundwater Replenishment Trial in Perth, designed to build knowledge of the local technical, health, environmental and social issues associated with groundwater replenishment. The trial was completed in December 2012 and regulators indicated that it met all of the project objectives, so the Water Corporation hopes that the Government will enable the transition from a trial to a long-term operation, augmenting drinking water supplies. On the southern region of the west coast of the USA, a groundwater replenishment system has been operating successfully now for two years, according to Ralph Eberts. Valuable lessons have been learned regarding chemical dosing, ow equalisation, energy recovery, residuals management, etc, and the original plant has been upgraded to deliver a consistent 379 ML/d. One of the practical challenges for RO plants is unacceptably high levels of boron in the product water. An exhaustive study, reported by Elyse Harding, concluded that the most feasible operational strategy to reduce boron concentration would be to install speci c boron rejection membranes in all stages and operate the system with an RO feed pH of 6.5, at increased ux and optimum operating recovery. The overall boron rejection can be increased by ~32% by implementing this strategy. Getting back to groundwater, several papers were presented, painting a picture of many aspects of groundwater as a source to improve climate resilience. Straight groundwater modelling and management was featured by Andrew Watkinson in a study of Bribie Island. This study highlighted the importance of an adaptive management framework driven by continual improvement to sustainably manage groundwater extraction. Although revised modelling showed current practices to be sustainable, it identi ed that signi cant improvements to the monitoring and assessment of the operation are warranted. David Schafer also addressed straight aquifer management in his presentation. An integrated groundwater study in the Allanooka- Casuarinas area (WA) substantially improved understanding of the available fresh water resource. Detailed hydrogeological understanding of the shallow (maximum 200m thick) fresh groundwater- ow in the centre of the investigation area, will allow strategies to be developed on how to best manage and preserve this important resource. The area of freshest groundwater has already been targeted for future expansion of the Allanooka bore eld, which is the sole water supply for Geraldton and nearby townships. The prize for best paper in the conference was won by Andrew Watkinson, on behalf of his co-authors. Their study demonstrated that changes seen in the source water quality of two WTPs on the Mid-Brisbane River could be attributed to the reconnection of groundwater to surface water in the Lockyer Creek catchment, following signi cant recharge after the 2011 oods. This understanding was achieved through the development of a Groundwater Visualisation Systems (GVS) model that allowed the analysis and interpretation of a complex and diverse dataset. The last of the groundwater-alone papers, from Kresho Zic, showed that numerical simulations demonstrated that high-yield groundwater bores and targeted perennial systems can be used to control groundwater levels, both within farm areas and the buffer zone surrounding the proposed development. Graphical presentation tools were developed to communicate the complex hydrogeological results to a range of stakeholders. Nick Turner sketched out the Perth water strategy, which includes transfer of groundwater abstraction from environmentally sensitive areas of super cial groundwater to deeper con ned aquifers, in parallel with the use of groundwater replenishment, using highly treated recycled water and further expansion of seawater desalination. Brisbane's stormwater harvesting system on Southbank, Rain Bank, was the subject of David Hamlyn-Harris' presentation. Rain Bank's innovative design enables stormwater harvesting to be applied to a highly urbanised catchment, greatly reduces water consumption, contributes to cleaner, healthier waterways and actively demonstrates stormwater harvesting and water conservation. The nal arrow in the quiver of climate resilience is water ef ciency. Jo Greene spelled out successful outcomes in Hunter Water's ef ciency and conservation drives, especially in the non- residential sector; however, she noted that long-term success depended on resources. The project has shown great progress in identifying water saving opportunities for project participants. In similar vein, Alice Water Smart is currently focusing on assisting participants to realise savings. Planned consumption reduction targets are being readily achieved with the town's overall water consumption having dropped by about 10 per cent on previous years, according to Les Seddon. Lisa Ehrenfried noted that, during the Victorian drought, laundries were a responsive industry sector for water ef ciency programs. A good relationship with their water utility is appreciated by Melbourne consumers, who also felt that their water utility had a strong in uence on their water-saving behaviours. The main drivers to participate in the program were "Corporate Social Responsibility" and "Being convinced by the information". WA has a broad ef ciency thrust, which was described by Ben Jarvis. Bene ts have been diverse: Kalgoorlie's new smart meters have reduced the risk of snakebite; in other communities, residents and/or community groups are reading meters, hence cutting operating costs, providing local employment and improving social cohesion. WJ Part 2 of our Ozwater'13 Report will appear in our August 2013 issue.
Water Journal May 2013
Water Journal August 2013