Water management options for urban and rural Australia
Recycling stormwater – new urban water supplies using aquifer recharge
Peter Dillon
CSIRO Land and Water, Waite Campus, Adelaide
CSIRO Water for a Healthy Country Flagship
Peter Dillon is a research engineer who leads the Water Recycling and Diversified Supplies Stream within the Urban Water Theme of CSIRO’s Water for a Healthy Country Flagship. Through his team based in Adelaide, Perth and Brisbane, CSIRO has contributed to the advances in managed aquifer recharge (MAR), water recycling and harvesting of stormwater for 18 years by providing scientific support for many organisations implementing first of breed water recycling systems. Peter is the founding chair of the Commission on Managed Aquifer Recharge of the International Association of Hydrogeologists and instigated MAR-NET a UNESCO-IAH network to facilitate safe uptake of MAR for drinking water supplies especially in developing countries. He is a founding member of the Australian Water Association’s special interest group on water recycling and directed its Australian Water Conservation and Reuse Research Program. He has led and contributed to a number of international and national research projects, published scientific contributions and run numerous training events on MAR.
Recycling stormwater – new urban water supplies using aquifer recharge
[SLIDE: Recycling stormwater ‑ New Urban Water supplies using aquifer recharge]
Water is an all pervasive topic. It is an exciting topic because we are in a period of not just climatic change but also institutional and behavioural change as we respond to the new challenges.
A large number of people have been working in this area over a period of time so I'm just the representative of this broader group.
[SLIDE: Contents]
I'll be talking about managed aquifer recharge (MAR) and then some of the factors that facilitate the application of managed aquifer recharge in Australia.
[SLIDE: Types of recharge enhancement]
When I'm talking about managed aquifer recharge, I am not talking about the clearing of mallee and increased enhanced recharge through those means. That is unintentional recharge enhancement.
I am not talking about recharge disposal of effluent into septic tanks, for example. Yes, that does recharge aquifers, but it is unmanaged recharge. I am talking about managed recharge for the purpose of recovery of that water for beneficial use, or for environmental value.
[SLIDE: Types of managed aquifer recharge]
The terminology is something that I have had a bit to do with. People were using all sorts of language to describe the myriad types of managed aquifer recharge – now we have a standardised terminology that we can work from.
A couple of the terms that will come up in my talk are 'aquifer storage and recovery' (ASR), which is when we inject water down a well and recover it from the same well; and 'aquifer storage transfer and recovery' (ASTR), which is when we recover that water from a different well, so it has a minimum guaranteed passage through the aquifer.
I won't go through all the other types of recharge, but what I would say is that when we come to a particular situation we look at the landscape, we look at the hydrogeology and determine what is the appropriate response to make in this area, rather than try to make one size fit all.
[SLIDE: Confined aquifer ‑ aquifer storage and recovery]
Each recharge project has seven components. There is some capturing of water, some pretreatment, recharge, storage in the aquifer, followed by recovery, maybe some post‑treatment, and then the end use. So that's common to recharge schemes.
[SLIDE: Unconfined aquifer ‑ soil aquifer treatment]
This slide shows another type, where we might infiltrate water intermittently from a recharge basin attached to a sewage treatment plant. That water can be recovered for irrigation purposes.
[SLIDE: Water treatment depends on end use...]
What I want to focus on tonight is how we can use aquifer characteristics to create waters that are of great value to us – for drinking, industrial, irrigation and even sustaining ecosystems – from a range of sources, including stormwater and recycled water.
In general, this slide shows different types of capture mechanisms. There are some water treatments before recharge. This isn't a recipe. The treatment is actually tailored to the particular site, to the quality of water that you are starting with and that you want to finish with. These are just examples, if you like, that have been used.
Generally we find that we don't need much post‑treatment, because the quality we have put into the aquifer and the quality that we get from the aquifer is very good.
In the Water for a Healthy Country program we have been aiming to increase the value of water in Australia. Much of the effort of the people in my group has been focused more towards the drinking-water end of recycling.
[SLIDE: Factors that assist MAR implementation]
Eighteen years ago when I started my very first project, I wasn't aware of how many barriers there were to implementation of successful projects. If I had been, I probably wouldn't have gone any further! But when you get to the top of one dune then you see the next – that's been the way we have progressed through this.
What we have found is that there are some things that really do help to make it possible to recycle water effectively. I will go through the six points on this slide and I will use examples to illustrate these points.
[SLIDE: Factors that assist MAR implementation: #1]
The first factor is having maps showing the availability of suitable aquifers. If you want to invest in storing water in the ground, you have got to know that there is an aquifer there. It is quite expensive to find out by trial and error.
[SLIDE: Combined map showing best storage potential from all aquifers]
This is a map of Melbourne. The dark blue patches represent the highly prospective areas for managed aquifer recharge. The lighter shades represent low opportunities.
So if you live in Melbourne and you want to do a managed aquifer recharge project, you can look at the map and see whether it is possible in the area you have in mind. This saves a bit of expense and a lot of heartache for people who go into terrain where you just can't create an aquifer.
[SLIDE: Factors that assist MAR implementation. #2]
Local demonstration projects and information sharing are really important because not only do proponents need to get information about how successful a project is and what is required for viability, but regulators also need to have some practice in understanding how to regulate for managed aquifer recharge. Having demonstration projects gives you both.
[SLIDE: Burdekin Delta, Queensland Australia]
The first managed aquifer recharge projects took place in the Burdekin Delta in Queensland in the 1960s, where sand dams were put up on the river. There were recharge bits constructed because irrigation use was driving the water table below sea level and there was a fear of saline intrusion.
When there was excess flow in the river, recharging the aquifer made a lot of sense. The irrigators have been able to sustain their industry. Forty‑five gigalitres a year annually is recharged in that area at an average cost of 5 cents a kilolitre.
[SLIDE: Stormwater ASR development in South Australia]
The next developments occurred in South Australia, with stormwater use for offsetting the salinity increase in an over‑exploited aquifer used for irrigating viticulture. One astute farmer put a pipe through to the ephemeral stream when it flowed. He took the fresh water and injected it into his well to freshen it up. He was able to keep his vines alive. Soon there were 18 farmers doing the same thing. This is a way of sustaining some agriculture in that area.
[SLIDE: Research commenced 1992. ...]
The first urban application came in 1992 at Andrews Farm in South Australia, a northern suburb that was developing. There was a requirement on the developer that peak flows from the subdivision should be no greater than they were prior to the subdivision being established. So the developer had to put in flood control measures such as these flood control dams.
This is a very dry area. The developer recognised that if he could green up the area he could get a lot more for the houses. So he invested in helping us to do an aquifer storage and recovery project there to test the viability of storing urban stormwater beneath the ground in the aquifer.
If it wasn't for some local heroes, who were willing to stick out their necks and have a go at some projects, we wouldn't have made any progress. The man who was responsible for this, Alan Higginbotham, unfortunately died last week. I think he has left a legacy, apart from the many houses that he built.
[SLIDE: The paddocks wetland ASR for irrigation of ovals...]
As time has gone by, techniques have developed further. We now have SCADA systems, data acquisition systems that control injection operations; they are very sophisticated control systems that enable us to get better operations out of the aquifers.
[SLIDE: Stormwater ASR for industrial water supplies]
We have seen an increase in the scale of projects over the years. The one at the top left of this slide is a large one in the city of Salisbury. The one on the bottom right is on a small island off the coast of Arnhem Land in the Northern Territory, where the Aboriginal community was running out of water at the end of each dry season. In spite of having 2 metres of rain in the wet season, the aquifers were very narrow along the island, and saline intrusion was occurring towards the end of the dry season.
We drilled a hole into a deeper aquifer and we are storing the fresh shallow groundwater during the wet season in the deeper aquifer as an emergency supply to meet the end of the dry season needs of the community. So there is a whole range of approaches.
[SLIDE: Filtered stormwater ASR into hardrock]
This example is in suburban Melbourne, where we have a very poor quality aquifer – a golf course that was running out of water. We provided a high level of treatment to keep that operation working, through micro‑filtration and granular-activated carbon filtration prior to injecting that water.
[SLIDE: Bolivar reclaimed water ASR research project]
Bolivar Reclaimed Water ASR Research Project was established because wastewater from the Bolivar sewage treatment plant in Adelaide was being irrigated, sent out, treated and sent through a pipeline to supply agricultural irrigation. It was recognised that the demand for water was increasing in summer, but there was very little use for the pipeline in the winter. So storing the effluent – the recycled water – beneath the ground in the aquifer over winter created an increased volume that could be used for irrigation, and also reduced the amount of nitrogen being discharged into St Vincent's Gulf.
[SLIDE: ASR with stormwater to dilute reclaimed water ...]
Here we have a smaller managed aquifer recharge project for stormwater. Together with the recycled water from the Bolivar sewage treatment plant it feeds into a mixing tank. That water is then blended to go through a third pipe system, a supply system for garden irrigation and toilet flushing at Mawson Lakes, a subdivision of northern Adelaide.
[SLIDE: Construction of infiltration galleries....]
At the CSIRO Floreat laboratory site in Perth we are using reclaimed water from the Subiaco waste water treatment plant to infiltrate it through the sandy aquifer into the limestone below to prop up groundwater levels which have been depleted through neighbouring wells from the many householders that use groundwater. This is a way of helping to maintain wetlands.
[SLIDE: Alice Springs Soil Aquifer Treatment]
In Alice Springs the wastewater treatment plant used to suffer overflows into Illparpa Swamp, with consequent health problems for the local community. Now there is a managed aquifer recharge project and soil aquifer treatment. The treated water goes out into the basins where it infiltrates down and the intention is to recover it for irrigation use.
[SLIDE: ASTR: Stormwater to drinking water project]
At the aquifer storage transfer and recovery project in Salisbury (SA), stormwater is treated in a wetland, injected into an aquifer and then recovered from neighbouring wells. What we found is that the water is fit for drinking. We have taken a brackish aquifer and a stormwater source to produce a drinking-water supply which is highly cost‑effective.
On the occasions that this water has been bottled it has met drinking water standards. We have a bit more work to do to demonstrate that we can do that on a day‑by‑day basis.
[SLIDE: Locations and types of MAR in Australia in 2010]
These are the locations and types of managed aquifer recharge currently operating in Australia. (I worked on the figure that was produced for 2010 and put a cross on all the new ones that have appeared in the last two years.) So there is an ASR project with reclaimed water in Perth; there are several projects taking place in the Geelong area; in western New South Wales; western Sydney; and in the coal seam gas area of south‑east Queensland.
Gradually we are getting a bigger cast across Australia. The expected uptake for managed aquifer recharge in urban areas is about 250 gigalitres per year. I think at this stage we are at about 10 gigalitres.
[SLIDE: Cost scale of MAR in relation to typical costs of water …]
The costs from those demonstration projects show at about 5 cents a kilolitre for irrigation supplies. The average from eight stormwater ASR projects for non‑potable use was around $1.12 a kilolitre. We think it is going to be a little bit more than $1.20 a kilolitre for potable use.
[SLIDE: Economics of stormwater ASR compared with seawater desalination]
It is quite cost‑effective when we compare it with desalination. We are talking less than half the cost in terms of dollars per kilolitre, and less than 3 per cent of the energy use. I am not saying we should be doing this instead of desalination, what I am saying is that putting them both together gives a more robust supply and a cheaper outcome than just using one alone.
[SLIDE: Factors that assist MAR implementation. #3]
Australia has made a lot of headway in developing guidelines on managed aquifer recharge to protect health and the environment. When we first started people would say: Is it safe? How can you show it? Now we have guidelines that people can adhere to.
[SLIDE: National Water Quality Management Strategy]
Australia has a national treasure which is the National Water Quality Strategy. And if you go away with one thought from this talk, it is to be grateful to the people in the past who created this strategy and who put a science base under water quality in Australia.
[SLIDE: MAR Guidelines in Relation to NWQMS]
The managed aquifer recharge guidelines came out in July last year and they deal with not only the ellipse, which is recycled water, but they also deal with natural sources of water like groundwater, and also drinking water and water from rural catchments or pristine areas.
So we have a very coherent set of guidelines. They all link together and they really give us a very solid basis from which to move forward.
[SLIDE: Key hazards in source water, ground water and aquifer materials for MAR projects]
The guidelines deal with a range of water quality issues like pathogens, inorganic chemicals, salinity nutrients, organics, turbidity and radionuclides. They also deal with the things that are specific to aquifers: the pressures and flow rates, volumes and levels in aquifers, contaminant migration in fracture rock and karstic aquifers, aquifer dissolution and aquitard and well stability, impacts on groundwater and ecosystems and also greenhouse gases.
[SLIDE: What soil and aquifers do... ]
There are three things that aquifers can do which the Australian guidelines take into account that guidelines elsewhere do not. They allow for sustainable removal of hazards, like those pathogens which are inactivated in aquifers. We can rely on the aquifer for the treatment process, where it has been demonstrated that it is effective. Hazard removal which is ineffective, such as salinity – if you put salt water into the aquifer that's what you will get back out.
If you put water that contains metals into an aquifer it can be problematic because ultimately it might break through and you are creating a time bomb for the future. The way to deal with that is to reduce the concentrations of those substances to a level that is sustainable in the system before you inject or recharge.
[SLIDE: Concept of attenuation zone]
And then there are new hazards that are introduced by aquifer interaction. If you put fresh drinking water into a drinking water aquifer you can recover water that is not fit for drinking, simply through a mobilisation of metals that might be present within the aquifer. Geochemical processes are taking place and you have to be aware of them. You modify the source water so that those reactions are inhibited. Our guidelines are unique in that way. They deal with the attenuation of hazards. Attenuation takes time in the aquifer – it takes a certain volume of the aquifer around the recharge point for the concentrations of those hazards to decline to acceptable levels.
[SLIDE: Zones of influence of a MAR operation]
In any recharge area you might have a storage zone and an attenuation zone, which is that zone beyond which the environmental values of the aquifer continue to be met, and a water quality impact zone which is where the water you have injected is having an impact on the quality of the water in the aquifer.
In many cases we are going into brackish aquifers, so the freshened zone is now useful for high value purposes. Then there can be hydraulic impacts that extend well beyond the water quality impact zone. Having good hydrogeological knowledge is essential for running these projects.
[SLIDE: For each hazard guidelines document]
The guidelines go through the sources of the hazards and how you manage them, the preventative measures and what sort of monitoring you might do.
[SLIDE: Stages in establishing a MAR project... ]
When we start a managed aquifer recharge project it is not like starting, say, a reverse osmosis project. You can buy a membrane and you can see what the specifications are. When you come to an aquifer you don't know how it will perform until you have tested it. So, we have to start from a very low information base and try to get to a position where we decide whether to proceed with the project on this site or should we call it quits? Is it too hard to do?
The guidelines are set up to address the uncertainties in a systematic way, to bring about decisions at an early point as to whether to proceed or not. The proponent of the project has a fair idea of the degree of difficulty of the project, and so the cost of investigations, before they commit to them.
[SLIDE: Summary MAR Guidelines]
The guidelines also talk about other issues such as clogging and recovery efficiency. These are the two killers of projects from an operator's point of view: can you get the water into the aquifer, and can you get it out again?
We decided we would include these operational parameters within the guidelines because unless someone is operating an economically effective project it is very hard for them to make the adjustments to ensure that the environment is protected.
[SLIDE: Factors that assist MAR implementation. #4]
‘Water allocation policies that account for managed aquifer recharge’ is the fourth factor on the slide. I said earlier how important the National Water Quality Management Strategy is, and in this area the National Water Initiative has been absolutely crucial to the development of managed aquifer recharge in Australia. There is still some distance to go, but it's having a big impact.
[SLIDE: Purposes and value of MAR]
Firstly, let's look at what the values are in managed aquifer recharge. Maslow’s hierarchy of needs can be used for these categories: sustaining the environment; drinking water and water for basic human needs; economic development and buffering drought. So we get greater value out of keeping storage in the aquifer to be able to ride through the drought than we do just by putting water in and taking it out every year – taking out as much water as we put in. It's great for economic production, but it doesn't increase the resilience of the water resources system.
[SLIDE: MAR provides a buffer storage in wet years …]
How do we move when the dollar driver for commercial projects is to get as much water out as quickly as you can put it in? How do we move to create additional value out of managed aquifer recharge schemes that will be of benefit for national resources management? That's the thing we have been grappling with in the last few months in a project for the National Water Commission.
[SLIDE: Water policy framework accounting for MAR]
What we've come to is a national water initiative approach to governance of managed aquifer recharge – dealing with entitlements, periodic allocations and use conditions or obligations – then applying those to each of the four components of managed aquifer recharge shown in the slide.
If we are talking about stormwater harvesting, do you have an entitlement to stormwater? Well, you will find it very hard to find anyone in Australia that's got an entitlement to stormwater. The ACT is the closest to where that can occur. In other jurisdictions the concept of entitlement isn't there. It is very difficult to see how periodic allocation can take place without an entitlement.
When you are doing the first recharge operation in an area there is plenty of aquifer storage space. Let's say it is economic, let's say it is commercially viable, then everybody will want to do it. How much aquifer storage space have we got? There is going to be competition for it, so how do we deal with that?
And then on to recovery, we have stored this water, do we have any entitlement to recover it? In many states that doesn't exist at this stage. If you do the recharge, the water becomes part of the natural groundwater system and you have no greater access to that water than your neighbour.
[SLIDE: Pathway for policy implementation from regulation to entitlements]
We are interested in seeing if we can get up some schemes whereby we can move from the current arrangements, which are largely permitting arrangements, through to evaluating the size of the consumptive pool and the sharing options available and then an entitlement‑base system with fully specified entitlements and allocations.
[SLIDE: State of progress of policies enabling MAR]
If we look at the column ‘Entitlement and allocation policy for stormwater or sewage’, the ACT leads the way.
[SLIDE: Recovery entitlement descriptions for different aquifer characteristics]
Entitlement allocation policy for recharge doesn't exist in Australia at the moment. Entitlement for recovery of water, including transfer, does exist in South Australia but it is very site specific.
So we have a fair way to go. But there is a lot of willingness amongst the regulator fraternity because they can see that there is some benefit there.
[SLIDE: Transfer of water entitlements generated by MAR].
If you want to build a subdivision in Phoenix, Arizona, you go to the water bank and say to them, ‘Look, I need this much water’ and they say, ‘Well that will cost you that much’. Then that money is used to pay for the project to deliver that amount of water. And it works because they've got a huge aquifer underneath which is so transmissive that the water can be put in anywhere and taken out anywhere else, and the system remains roughly in balance.
In most Australian cities – Perth would be one exception – we don't have such aquifer systems. We've got brackish aquifers, so we need to have ways of getting recovery entitlements. Using mains water systems is the way of transferring entitlements. So we can store into a brackish aquifer and recover to mains and then the use can be somewhere else. That sets up a market which is as wide as the distribution system in the city. We need to have a market in order to get the trading operations up to a successful level.
[SLIDE: Factors that assist MR implementation. #5]
I'll just speak very briefly to holistic water resources planning.
[SLIDE: Sequenced management and policy framework – Murray Darling Basin]
This is a complicated diagram, but basically it shows a history of the development of the Murray Darling Basin where under the customary management of the original Aboriginal landholders there were low levels of diversion out of the river – the base flow was unimpeded.
As consumptive use increased – each of these steps might be a dam going in, for example – we eventually got to a point in the shaded zone of the diagram where the use actually started to impinge on the environmental flow requirements to maintain the system.
And so we have got an overallocated system. There is a lot of pain in bringing that back down to a sustainable system with cap and trade arrangements. There is political pain; there is economic pain for those irrigators who now don't have access to water; there is environmental pain, as we can see in the lower lakes system that has been severely degraded; and there is quite a lot of social angst as communities face an uncertain future.
[SLIDE: Sequenced management and policy framework ‑ relatively unallocated resource]
We don't want to see that happen with resources that are currently not unallocated but are also not overallocated. If we think about urban stormwater, some communities are thinking of that as a gift. Here's this great unallocated resource that we can do something with. I'll show you how important, how big that resource is in a few minutes.
But if we start from this position, what I would like to do is to maintain the environmental flows without impinging on them. By setting up some arrangements whereby there is a reserve pool, as we get more confident about the size of the resource and how much is allocatable, we can then increase the consumption to a sustainable level.
Of course, as you know, the total pool, the total replenishable source, is also changing with time, and in general decreasing as a result of climate change.
[SLIDE: Residential water balance per household]
This slide shows the size of the resource we are talking about, expressed in terms of kilolitres per household per year. The blue is stormwater. The green is sewage effluent that is discharged from these cities, and the yellow is the mains water that they use. So we can see that in every case the sum of the stormwater and the sewage effluent exceeds the volume of mains water used.
In theory, if we could harness all of the stormwater from the city and all of the sewage effluent we could have more than enough to supply a city's needs. But stormwater is very hard, and expensive, to capture. Unless you can store it somewhere – and perhaps underground is a useful place –it often flows off so quickly that you don't get the opportunity to harvest very much.
It represents a significant resource that is grossly under-utilised at this stage and presents a great opportunity for us. But, bearing in mind the previous slide, let's do it in a sustainable way.
[SLIDE: Diversified sources of water for Adelaide]
Australian cities are starting to diversify their water sources. One of the things that managed aquifer recharge does is to give us a new option for the recycling of stormwater and water from effluent.
Adelaide is largely dependent upon the Mt Lofty Ranges catchments and the River Murray, of course. The city has realised that it can't be so dependent on these as it has been in the past. It needs other options and is starting to invest in seawater desalination.
One of the sad parts of this story is that stormwater harvesting projects are being put forward simply to harvest money for stormwater harvesting and not necessarily to address a need.
So it seems that we are going backwards. If we are not doing substitutional use of stormwater for mains water then we are actually creating a new demand that the city needs to meet its available resource. So some higher level thinking is needed about the way that we go about these projects.
As I said before, about stormwater going into mains water systems, there is a catchment in South Australia where 800 megalitres per year can be harvested for non‑potable uses. Most of those non‑potable uses are new uses of water radiating around localised non‑potable distribution systems at the points where stormwater can be captured.
The gross harvestable water in that system is actually 5.7 gigalitres, which is significantly more. If that could go into the mains that would be a 100 per cent substitution for the Mt Lofty Ranges and the River Murray. If we can pursue this research a bit further there are real advantages in being able to demonstrate that we can recover water to drinking water supplies, because it creates a much bigger market for the otherwise wasted water.
[SLIDE: In a diversified portfolio each option contributes to a range of social and environmental objectives]
[SLIDE: Australian Asian and African Cities]
You may be wondering why Adelaide and Perth have featured so much in my talk. Is it to do with the hydrogeology or the climate? Well, certainly hydrogeology has a lot to do with it, but climate is also interesting. This slide shows a hydrological map of some cities around the world.
The vertical axis represents the rainfall in the driest six months as a percentage of annual rainfall. So the higher you go the more uniform the rainfall is. The lower you go the more concentrated it is during the year. The horizontal axis represents mean annual rainfall divided by evaporation, so it is an index of wetness, if you like.
Adelaide and Perth are the places that have the highest water storage needs, as well as Alice Springs and Darwin. But Melbourne, Hobart, Sydney and Brisbane have much more uniform rainfall so the need for storage is diminished in those places. We are identifying a lot with other parts of the world which have real water shortage issues and where managed aquifer recharge can provide a valued contribution.
[SLIDE: Factors that assist MAR implementation. #6]
Unified water resources management is another factor that we need to look at.
[SLIDE: MAR in urban water management]
I was told in the surveys that we've just done that on average it takes five different government departments to approve a managed aquifer recharge project, whichever city you’re in, because it is such an integrating type of activity. So we need to engage with urban planning, stormwater management, wastewater management, and water supply.
[SLIDE: Economic, social and environmental benefits and costs of MAR]
Managed aquifer recharge has a lot of benefits attached to it that are often not included in valuing the externalities of existing competing water supply projects –flood mitigation, improving urban amenity, improving coastal water quality. They're motivating factors for the establishment of many projects, but not yet taken into account in a holistic way.
[SLIDE: Proposed roles of a water bank for consideration in Australian capital cities]
I think a water bank is an approach that we should look at for the future. When Pharaoh had his dream about the five skinny cows eating up the five fat cows – it is fairly clear that we have access to better information than he had and it is telling us that we have got climate variability on our doorstep – with Joseph's help he developed a food bank! It's probably time that Australia thought about a water bank. A water bank would be localised to cities but would have the common elements of purchasing water; water supply planning; government policy and decision criteria to engage those externalities appropriately into decision‑making; and getting financial institutions involved.
This could be a great thing for superannuation funds, which are themselves a way of preparing for tomorrow today. Investment in water infrastructure in urban areas is a guaranteed demand.
[SLIDE: Conclusions]
Because managed aquifer recharge is at the interface of different jurisdictions and disciplines it has taken a long time to gain traction, and I'm continually amazed how slowly it has taken place in Australia.
In the last few years it has rapidly accelerated because of National Water Commission investments in projects and the commitment of various partners who can see opportunities. But largely it has taken place where it is commercially viable, and I think we need to think about what the opportunities might be for us to harness managed aquifer recharge for much more longer‑term benefits for making robust water supplies, and for protecting drinking water and aquifers. We need to deal with these externalities, and perhaps a water bank is a way of dealing with them.
Clearly we've got demonstration projects and they are of great value. There are a whole lot of other projects, stormwater to drinking water, which are coming on now. Saline intrusion barriers haven't yet been built in Australia and there are opportunities for them in coastal areas.
It is intended that managed aquifer recharge should be a foundational water management method that becomes standard practice where it is viable and cost‑effective. I'm not preaching that it is a universal panacea, but it has got a place and it needs to be looked at. If it is not viable don't do it.
Practical measures have been adopted in Australia and are of interest elsewhere; already the guidelines have been picked up and used in China. We are expecting to see a lot more uptake of both the guidelines and the concepts in the policy statements that we have been developing as we progress, especially for looking at third world water supplies for cities that are short of drinking water.
I am flying a flag that perhaps water banks are a prospective avenue for securing supplies from increasingly stressed resources.
[SLIDE: Resources and conferences on MAR]
This slide lists some resources that are available.
[SLIDE: Acknowledgments]
I would like to thank a host of groups that have been working with us to help make some of the changes that I have been talking about here.
Discussion
Question: Has there been developed or is there being developed a national graphic database of aquifer potential throughout Australia? It seems to me that that's a fundamental, if people don't understand what the potential is and decision‑makers throughout the system don't understand the potential, all that information is not going to be useful to them.
Peter Dillon: The National Water Commission has invested in studies in Adelaide, south‑east Queensland, and the central coast of New South Wales. Studies have previously been done in Melbourne and Perth. There are a number of consultancies that the NWC has administered for regional rural towns and, I believe, some rural irrigation areas, but I am not really au fait with the full scope of that work. It is the sort of work that needs to be done at a moderately small scale. If we have a national map, you can't see it. The texture is much finer than that. It is a much more complex thing than a regional scale map, but it is certainly something that in the places that are water stressed, or where there are suitable sources of water available, could easily be done better than it is now.
Question: But surely it's a national issue and should be approached that way and integrated into a single database.
Peter Dillon: I would be very happy to see that.
Question: As a non‑scientist whose father had an anecdote about how he lost his teeth from drinking tank water – he was brought up on tank water and there were no nutrients in it – your talk seemed to focus on quantity. What about the quality of this potable water?
Peter Dillon: The guidelines really do focus on quality. The requirement is that if you are going to use the water for drinking then it has to meet drinking water standards. So the onus is on the proponent to demonstrate that they have in place water that is a potable quality, and also that they have got in place all of the requirements that are expected of the supplier of potable water that they can ensure the quality will be managed well so that that water quality is assured.
I guess that every water source and every aquifer will end up with different aesthetic values attached to it, but the water will have to be treated to the level that the community is willing to accept.
Question: I am not a scientist and I know nothing about aquifers, but I would like, if I could, to be greedy and ask you three questions. The first one is a bit tangential, but as an Adelaide man I am conscious that one of the three or four operating uranium mines in Australia is at Beverly Hill in the northern part of South Australia. It is run by a US‑based private company. It is projected that the next operating uranium mine in Australia will be one operated adjacent to that Beverly Hill mine by an Australian company. They are using a process called acid leaching, whereby lots of acid gets pumped into the ground to try and dissolve the uranium, and then it is extracted.
As one who knows nothing about these matters, could I inquire of you, as a water man, whether the idea of pumping acid into our ground seems a good idea? And secondly, whether there is a process around such operations, and that you, as a water man, are happy with the concern that is given to environmental issues? That's question number 1.
Question number 2 is really an observation. In a country like Australia, where water is so scarce, I am just stunned and amazed that so little of the issues that you pointed to get an airing in our mainstream press. I'd be very pleased to hear your comments on how you or your team, or the CSIRO, might be encouraging greater attention by government and the public on water management issues.
And thirdly, one has the impression that during the previous government the CSIRO in general had a tough time but the current government has been even worse in terms of what it is offering or not offering in terms of allocation of resources to the kind of activities undertaken by your organisation.
Could I invite you to be as politically incorrect as you like and give us a perspective on whether you are getting the kind of resources that you need to address the issues that you need.
Peter Dillon: Concerning Beverly Hill, that's an Environmental Protection Agency issue. They would have looked at what the environmental impacts would be on acid leaching and what the controls would be on those systems. We can see from things like the Gulf of Mexico that not everything always works the way you would like it to work, but there should be checks and balances in place. So I don't know anything about it. I'm just relying on the EPA to do their job.
Press and public, yes, I think we could be more active in the media. When we start talking about indirect potable re‑use it generally creates a reaction. I think the Canberra press has actually done a bit of a disservice to that cause in Queensland at the time of the western corridor scheme, just before the Queensland election. It is not an issue that we should shy away from, because we have got solid scientific evidence that should be put forward, and the community does need an opportunity to understand the issues in order for them to have reasonable responses. We might not convince everyone, but I think having a scientific base is a necessary starting point to having a reasonable dialogue.
I'm not going to comment on CSIRO having money.
Question: I just wanted to know what kind of timeframe you thought there would be before there would be a viable process to run MAR for subdivisions around the country.
Peter Dillon: My hope would be three years. We already have three years’ worth of data. We have a paper that has been accepted by the Journal of Environmental Quality on the risk assessment that has been done at the ASTR site. We need to go ahead with the implementation of the treatment processes and monitor them over a three‑year period, so we have factual evidence to put on the table to say that this is the quality of water we produce, and this is how it compares with the alternatives that are available through the mains.
Question: While it is true that we have the least water per unit area of any continent, we have actually got the most water per capita of anywhere as a country, certainly as a continent. So what's the problem?
I suspect the answer may be in that table you showed where the rainfall is scaled by evaporative demand. I suspect that may be the reason we have strife, apart from the fact that we haven't been organised in the past. The evaporative demand is very large in Australia, given the rainfall. Could you comment on that?
Peter Dillon: In terms of rainfall – this is on a land area basis – we also have very high evaporation, so we aren't lavishly well‑off with water. But I really think, coming to the first part of your question – why is it that we are so water-poor when in fact we are also water rich – I think the answer to that is the way we manage our water. If we look in our urban areas – Canberra is an exception because when it rains here, what you don't have goes down the river and creates an environmental benefit, and an economic benefit elsewhere – but if we think about the coastal capitals that are discharging water into the sea, they have increased their discharge of water into the sea as a result of hardening surfaces, and that water is not being tapped and those people are now desalinating the sea water to get it back.
