Goulburn’s largest dam, Pejar (9000 megalitres capacity), is officially empty with just an inaccessible 3 megalitre puddle on the bottom. Combined reserves in the remaining two storages (Sooley dam and Rossi weir) are dismal with less than 4000 megalitres to sustain a city of more than 20 thousand people. Faced with the pressure of Level 5 water restrictions, current daily consumption is around 5 to 6 megalitres. This represents a massive achievement by the community being around half of the previous 5-year average. The City Council has relaxed normal restrictions on household greywater recycling, increased groundwater extraction, built a pipeline to pump water from local ponds, and (optimistically) increased dam wall heights. But still the potable supplies continue to plummet. If rainfall patterns continue, Goulburn could be waterless by this time next year.
Pejar Dam - November 2005 (note weir in foreground!)So what is a pioneer rural Australian city to do when faced with such adversity? One identified option is to truck potable water in from outside the region. This is estimated to require 40 semi-trailers working almost around the clock at a cost of $1million per week. I expect to hear at least a few people arguing that this is the preferred option sometime soon.
The other identified solution for Goulburn residents involves indirect potable recycling. The touted scheme would entail reclaiming 20 per cent of the city’s treated effluent and cleaning it to a very high quality by established advanced water treatment processes. This water would then be transported back up into the catchment to eventually find its way, via a series of ponds and wetlands, into Sooley dam.
The greatest obstacle, of course, will be winning public favour for the plan. The likely level of public favour is yet to be properly tested in Goulburn and the proposal will surely have its detractors. But can the city’s practical and resilient population work cooperatively to find a solution?
The most important factors will be the willingness and ability of the City Council to engage the community. This will require high levels of openness, transparency and accurate information provision. Any intelligent community will naturally have concerns and questions. It will be the council’s responsibility to address these honestly and completely. With something as important as water supply, people are entitled to have their concerns properly responded to in order to be fully assured that potential risks to public health are comprehensively managed and controlled.
Like Toowoomba, Goulburn has applied for Commonwealth Government assistance to fund the development of a potential potable water recycling scheme. However, having perhaps seen the error of forcing a divisive early referendum on the community, the Government have provided Goulburn with an initial $50,000 funding towards a community consultation process. This approach should be applauded as an absolutely essential first step.
Media reports this week suggest that Goulburn may be the pioneer Australian city to implement a planned potable water recycling scheme. Somehow I suspect they may be correct.
Whadda you reckon?
9 comments:
In don't know anything about the Goulburn mayor, but I look forward to seeing him/her on television saying things like "It wont be compulsory to drink recycled water. People who don't want to drink it can buy bottled water" deja vu all over again!
One persons "pioneer" is another persons "lab rat"!
The water recycling schemes proposed for Goulburn and Toowoomba rely totally on it eventually raining significantly enough to boost the current water levels in existing supplies to maintain the flow. A drought is not going to magically disappear just because a city decides to recycle its waste water for drinking. I think it is highly unethical for scientists and water recycling companies to jump on the fears of a community in the grips of a severe drought to pursue there idealisms of why we should recycle water for drinking. This is not going to save Goulburn or Toowoomba from the drought it will just slightly delay the inevitable and it gives people false hopes!
Greg, I couldn’t agree more.
Water recycling is not an infinite source of water and any person would be wrong to think (or say) that it was. However, recycling does have the potential to significantly relive pressure on water supplies. After all, about half of what we use ends up at the sewage treatment plant and could potentially be used again. How much of that is realistically available to recycle will depend on environmental flow requirements etc.
Eventually, every city has a sustainable limit and water availability is likely to be a key limitation for many parts of Australia. We may simply have to accept that some cities have reached (or are close to) their sustainable limit. Water recycling has the potential to expand that limit to some degree, but certainly not infinitely.
It makes me wonder where you stand on direct potable reuse.
I went down to Lake Annand in Toowoomba today and at the Council tent I was confronted by Cr Alroe and Jeff Nolan.
Cr Alroe said she had just drunk a bottle of Singapore NeWater and had grown a third ear!!!
What she did say in more sincere tones which made me prick my ears is that she strongly recommends that Toowoomba should not pipe the water into Cooby Dam but put the reclaimed water straight from Wetalla to the city mains at Mt Kynoch.
Looking at both Goulburn's and Toowoomba's proposal it is interesting to note that not all the effluent returning to the Bumana Creek catchment may pass through the RO unit.
The Goulburn RO unit is more to attain average TDS 400 and granular activated carbon is relied on "to ensure all health related substances are removed such as chemical endocrine disruptors" para 5 p5.
Two questions Stuart:
Why is RO touted as the EDC remover in Toowoomba when Goulburn is going to use GAC for that purpose on part of the stream?
Is Toowoomba's RO model better suited to direct potabe reuse than Goulburn's consistent with Cr Alroe's recommendation?
G’day Snow,
I described where I stand on direct potable reuse in my "response to Lyle Shelton" post. The bottom line is that I consider it to be perfectly viable, except for the issue of ‘demand and supply balance’. Unless you can perfectly match (over 24 hours) the rates of recycled water use and production, then you need to store it somewhere. You could try to blend it with variable ratios of water from the dam as it enters the city mains, but that just seems to me like an unnecessary complication. If it significantly saves on pumping costs then I suppose it might be worth investigating.
I think there is plenty of worldwide evidence (unplanned indirect potable) that even half-decent conventional treatment has been sufficient to prevent populations from having observable adverse effects from chemicals. Adding either GAC or RO is an effective way of ramping up the ‘safety factor’ way beyond any realistic risk to public health problems related to dissolved chemicals.
Chemicals may be what communities are most concerned about at the moment, but they are not where the real risks are. More than 99% of worldwide public-health problems from water are related to pathogenic organisms (as Greg recently pointed out). Viruses in particular, can cause illness at much lower concentrations than any chemicals.
So to ask which of RO or GAC is better suited for water recycling is, in my opinion, the wrong question (they are both overkill!). To compare real risks, we should be comparing the disinfection processes. That is, how do Toowoomba’s RO + UV (+ residence in the dam) compare with Goulburn’s ozone + GAC (+ wetlands etc)? The answer is that RO is a much more reliable barrier to pathogens than GAC. This, I’m sure, is exactly why the ozone process has been included for Goulburn. Ozone is an excellent barrier to pathogens, even killing protozoa for which chlorine is fairly ineffective. However, ozone would be beyond redundant in Toowoomba since the same results are achieved by RO (not to mention subsequent UV!).
I think some councillors have been drinking something more then just bottled recycled water, perhaps it is the only way they can come to grips with this childish taste testing crusade there on! There are very serious risks in putting the treated water directly back into the cities water mains! It is just another sign that some of our councillors aren't very informed on AWT and another reason to vote no and boot them out at the next election and hire some more intelligent people.
It seems to me that in terms of amount of water available per person, things are almost 2x as bad in Goulburn than in Toowoomba.
Assuming-
Toowoomba: 28400 ML / 94000 people = 300 L/person.
Goulburn: 4000 ML / 22500 people = 180 L/person.
Yes anonymous,
I agree with you in principle, but I think you mean 300 kL/person and 180 kL/person!
...otherwise the dams would both be empty before the end of this week...
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