Ten days ago, it was announced on the anonymous Toowoomba-based Water Futures blog site that ‘there is a strong rumour that the "Think before you agree to drink" book has re-invented itself for distribution to Brisbane households. The rewrite is expected to shake the Government and the Water Industry to the core and fully engage the Brisbane community in the debate’.
The word ‘rewrite’ had me expecting that there might be some substantial new information. -Perhaps an analysis of the economics of competing water delivery options; -Possibly a critique of the role of the private sector; -Potentially a discussion of societal impacts of potable water recycling. I was looking forward to reading it and providing a further detailed review.
The Brisbane version of TBYATD was released on the Water Futures blog site this weekend and I can only say that it is most disappointing. Not only is there no new information to ‘shake the Government and the Water Industry to the core’, even basic factual errors have not been corrected.
For example, if Manners and Dowson are going to quote the book 'Our Stolen Future' they should at least cite the correct authors (Theo Colborn, Dianne Dumanoski, and John Peterson Myers). Sheldon Krimsky wrote a completely unrelated book called 'Hormonal Chaos'. Manners and Dowson may not have actually read either of these books, but since I have previously pointed out this error of fact, it is a mystery why it has not been corrected in the ‘rewrite’.
Similarly, the significant confusion between the impacts of conventionally treated discharged effluent in the environment and advanced treated recycled water continues to permeate TBYATD from front cover to back. I can only conclude that the misunderstanding and confusion that this is likely to impart to readers is not considered by the authors to be a failing that is worthy of revision.
From what I can tell, the only thing new in the Brisbane version of TBYATD is a ballot paper on page 20. This invites people to answer ‘yes’ or ‘no’ to the question ‘do you want water sourced from sewage treatment plants and then treated, to be returned to the drinking water supply of South-East Queensland?’.
The Water Futures blog site states that ‘at a cost of hundreds of thousands of dollars this is probably the largest privately organised public vote in Australian history’. I suspect that any Big Brother eviction night would be considerably larger, but more importantly, the opportunities for multiple voting seem to be similarly encouraged as they are on BB. Names and contact details are ‘optional’ and responses can be posted, faxed and/or emailed to Manners and Dowson. In the 21st Century, it is unclear why some of the vastly more secure and verifiable means of voting, which are available on the internet, were not adopted. I think this is unfortunate since it misses a fine opportunity for more accurately gauging community sentiment.
I thought the Toowoomba-edition of TBYATD was a worthy effort to stimulate discussion about some important issues relating to water recycling and to environmental chemicals. However, given the feedback that I have now provided, I think it is quite disappointing that the ‘rewrite’ would apparently make no effort whatsoever for improvement. Surely another lost opportunity.
I encourage you to read my earlier review.
____________________________
Update: The Courier Mail is also running a blog on the same topic, which you might like to check out.
52 comments:
A good example of a more secure online voting method is that set up by QLD Liberal leader, Dr Bruce Flegg: http://www.wateroptions.net/campaigns/1/
The site has been up for quite a few months now and received a reasonable amount of publicity. 145 people have voted for potable recycling and 17 have voted against it. But I suppose the real result is that around 4 million South East Queenslanders have more immediate concerns in life. Sorry Stuart!
What are you trying to say Annette!? Hmmm...
Stuart Did you see Channel 7 News to-night?
London dose not drink recycled sewage water and their people made it very plane.
When the people have their chance to vote we will see what they want and who they believe.
G’day Anonymous,
No, I didn’t catch the Channel 7 news, but I can well imagine what was said. We’ve been through this a number of times now and I suspect that you know the facts as well as I do. However, I’ll be happy go over it once more with you.
London is an example of 'unplanned' or 'incidental' indirect potable water recycling, but it is a much more extreme example compared to Richmond in NSW, which we have looked at in some detail. There are close to 400 sewage treatment plants that discharge treated effluent into the upper catchment of the Thames River. Thames Water then takes the mixture of natural run-off and treated effluent out of the river (usually via bank filtration) and treats it in preparation for delivering to the residents of London.
A major difference with this sort of system compared to the one planned for South East Queensland is that there is no advanced water treatment such as reverse osmosis or advanced oxidation. However, these treatment processes can be expected to improve the water quality in SEQ, not make it worse. So the inclusion of these processes does not make the ‘planned’ or ‘acknowledged’ approach to indirect water recycling any less ideal than the ‘unplanned’ or ‘incidental’ approach.
As we discussed in the comments section of a previous post, whether Londoners drink recycled water or not all comes down to how you define it and how you say it. But you and I know the facts and we know that the facts remain despite what anyone might say on the Channel 7 news.
Scientists need to put forward data to back up there claims as is the case with the 400 sewage plants in the upper catchment of the Thames river. Please supply us with a detailed map Stuart! Imo you are just pulling strings!
It amazes me how you continue to go solo on this whole drinking recycled effluent debate Stuart. Where is the backing of your senior brethren, those with 20 or more years expertise in this field then you. Why are not they here backing your claims? How come I cannot find them anywhere I look?
Why do you keep talking about unplanned indirect use, is it just to try and soften up our palletes for Beatties plan?
Could it be that in reality science could never prove that the water that will be dumped into Wivenhoe is really going to be safe. We don't want a bar of anything other then perfection here Stuart, we drink, bathe and cook in our dam water! Indirect use from rivers has no bearing on what Beattie is going to do, it is a completely different scenario and one that I am sure that most Australians do not go along with!
Saying that the treatment processes that are going to take place in SEQ will improve our water quality is a very bold and dangerous statement that needs to be backed up by an entire panel of experts and years of data not just one scientist who has displayed nothing less then a bias toward the whole science! Look what you find if you Google Drinking recycled effluent. Page after page of Aussie web pages on the subject. The entire concept of drinking recycled effluent in Australia is just a push by overseas companies to cash in on the driest inhabited continent on the planet and we do not want a bar of it! Beattie has bypassed our natural rights as people of a democratic society by not asking us to chose whether or not we want to use this water. Safe or not, we are the ones paying for it, something you seem to forget Stuart!
G’day Greg,
As usual, you have provided me with lots of interesting questions and discussion points.
Most (but not all) of the ‘close to 400 sewage treatment plants’ that I referred to are owned by Thames Water. Their website states:
“We collect wastewater from over 13 million people and a wide range of industries in the Thames Region and deliver it to 349 wastewater treatment works via a 67,000 km sewerage network with 2478 pumping stations. The wastewater, now treated to some of the most stringent standards in the UK and often approaching river quality, is returned to the aquatic environment where it is essential to maintain river flows and hence a rich and diverse biota”.
I’m afraid that I am currently unable to provide you with a map, but I too would be interested to obtain one and will keep an eye out.
I am certainly not “going solo” on the proposition that indirect potable water recycling can be (and is) undertaken safely. It’s got more to do with the fact that most scientists don’t have blog sites. The Queensland Water Commission has a panel of eminent scientists (much more senior and respected than myself), who will be sure to speak out if they believe that full safety is not being adequately protected.
Yes, you are correct to assume that I believe that most people will be more accepting of ‘planned’ indirect potable reuse if they understand that the ‘unplanned’ in direct potable reuse already occurs practically everywhere.
It’s true that if you Google “Drinking Recycled effluent” you find mostly Australian sites. However, this is largely because of the slightly different terminology used in different places. If you Google “Drinking Reclaimed Water” or “Indirect Potable Reuse” you will find a more international flavour.
A simple comparison to the QWC would be QLD Health to show just how far our trust would go!
Stuart is spot on. By definition one cannot prove an absolute negative, but plenty of scientists are willing to state that the risk of water recycling, if done properly and with adequate safeguards, is safer than the water that goes back into many of our inland rivers now.
A precautionary approach is appropriate, but not if the bar is set so impossibly high that it can never be reached.
If S-E Qld had adopted recycling a couple of years again instead of rushing it in now, our water 'crisis' would already be much reduced.
Thanks Andrew. I appreciate your comment!
Thank you for trying to inform on water recycling. I have only rain water available but work in the treatment industry. When I travel, I choose recyled water from RO rather than town water supply as it taste (dosen't taste) more like what I am used too. This could also be a feflection on my roof and gutters used to argue either case. At a plant recently, the final effluent running into iragation ditches was of far superior quality than the potable supply we tested as a standard. Thank you again for an informative Blog and keep up the good work.
Geez the drunk senator is blogging!
Stuart, just wait for the argument from my new booklet.
Purified Recycled Water is way too clean to drink.
I will only have water that cows and koala's have pissed in. Not sure if they take hormone replacement drugs, but they seem randy little buggers...so they old wrigglies will be just fine thank you very much.
Wait for the passionate sign off - "Save it for your Ironing Bleattie, I am not drinking demineralised water"
‘Ha Ha’, one of the hazards of allowing anonymous comments on this blog is that some courageous people think its okay to personally abuse others from behind a protective cover of anonymity. Its not courageous, its downright pathetic and -dare I say it- unAustralian.
Thanks Anonymous,
You may be joking, but it’s actually a valid point. The World Health Organization has investigated the concerns associated with drinking demineralised water for potential incorporation into WHO Guidelines for Drinking Water Quality.
However, you will be pleased to know that any indirect potable water recycling scheme in South East Queensland would remineralise the water prior to human consumption. Furthermore, the water would be naturally remineralised when mixed into the much less clean water in Wivenhoe Dam.
Well done ‘Ha-Ha’, You have managed to contribute only the second comment that I have had to delete in almost a year. You can say whatever you like about me and you are encouraged to say whatever you like about recycled water. But please don’t use this blog as a forum to personally abuse others.
Make it three please:
drunk on the public purse - lady - rough up - you get the picture!
Perhaps I should refrain from calling it recycled effluent as that is not correct. Would "water extracted from effluent" be more appropriate Stuart? The whole idea of it being purified recycled water and leaving out the effluent is a bit like saying that a tin of sardines is not a tin of fish! That is as funny as trying to make out you can squeeze pure water through a membrane and nothing else in the water would come through with it - I think that is where this whole drink it scenario started didn't it? I somehow doubt that the water will be cleaner then that which is already in Wivenhoe and there is no way we will ever know as you already said it will be mixed with the dam water so even if there was a problem they would probaly blame it on the original dam water anyway! As for Andrews comment about recycling, yes, the drought would not be lashing us as hard as it is if we had started doing desal a long time ago and we could have now started to send our treated waste water to them drought ravaged farmers in the lockyer and on the downs!
Hello Greg,
I think you could call recycled water by either of the alternative terms you have suggested (and many others too). Your meaning is fairly clear and that is what is important about effective communication.
However, it appears that I failed in this objective for clear meaning and effective communication in my earlier comment about unplanned indirect potable water recycling in London. What I was trying to communicate (very poorly, I admit), was that advanced treatment processes such as reverse osmosis and advanced oxidation would make the ‘planned’ recycled water in Brisbane cleaner than the ‘unplanned’ recycled water in London. I think the truth of that statement can be taken for granted.
Nonetheless, your alternative interpretation of my meaning is also perfectly reasonable. The water that comes from an advanced water treatment plant will have a miniscule amount of dissolved organic carbon compared to the dissolved organic carbon in the water in Wivenhoe Dam. Water that has arrived at the dam via run-off will have necessarily picked up significant concentrations of dissolved organic carbon…its normal and it doesn’t indicate that there is anything wrong with Wivenhoe water.
In case anyone missed it, here's the story about TBYATD in the Courier Mail. Here's a video of Deputy Premier Anna Bligh discussing it and here's a follow up featuring a rebuttal from the Chair of the Queensland Water Commission Expert Panel, Prof Paul Greenfield. Certainly and excellent job with media coverage, Snow and John!
Stuart, I would like to apologise for my younger brother's behaviour last evening. The little twit.
I often read your blog - I find your reviews of the water process interesting. I left the browser open at your blog when I went out last night with a few girlfriends and he thought he'd add some comments. He recently did a school project on the behaviour of our politicians and has taken a bit of a dislike to a certain senator. How did I find out about his blog comments? He told me this morning. You can bet I gave him an earful. Anyway - sorry for what he did and I will shut my door in future when I read your blog!
That’s hilarious Caroline! My younger brother had a go at sabotage too. The comment he posted in July last year as ‘Big Bhudda’ was obviously an attempt at humour, but it actually got an interesting conversation going!
Stuart, on Annette's comment, you should be aware that I voted yes 5 times just to help the numbers (using different email addresses) so the online process used by Flegg is not particularly regulated.
Will: Yes its clearly not perfect and relies on some degree of honesty, as does any electoral system.
But are your five yes votes still there? I could swear that there were 145 when I posted that comment and now there seem to only be 137. Maybe Dr Flegg has been undertaking some auditing??
Annette, without me telling them which 5 email addresses and names I used, they would be unable to tell (believe me) that they are my 5 votes. I got one of my friends to put in 8 so there is a lot of double counting.
Stuart, in relation to the Anna Bligh statement I read this page on the Thames Water web site were they state that "they collect wastewater from over 13 million people and a wide range of industries in the Thames Region and deliver it to 349 wastewater treatment works via a 67,000 km sewerage network with 2478 pumping stations. The wastewater, now treated to some of the most stringent standards in the UK and often approaching river quality, is returned to the aquatic environment where it is essential to maintain river flows and hence a rich and diverse biota." I find it amusing that Anna Bligh would misinterpret this as them recycling the water for human consumption! Is that were you got your figure from as well?
G’day Greg,
Yes. If you read my response to your first comment on this post (above) you will see that I have quoted and linked to exactly the same text.
Anna Bligh has not misinterpreted anything. It means that the treated effluent is placed back into the Thames River catchment from where much of it is then extracted and treated in preparation for drinking water for London. Its called ‘unplanned’ indirect potable water recycling.
Scientists slam recycled water claim
Ninemsn.com.au
Wednesday Mar 21 20:00 AEDT
Scientists whose work has been used in a booklet which claims recycled water can kill, cause infertility and change the sex of fish say they are annoyed their work has been taken out of context.
About 400,000 copies of the booklet are being distributed across Brisbane by campaigners who oppose a Queensland government plan to use purified, recycled effluent as drinking water by the end of next year.
Campaign spokesman and Toowoomba councillor Snow Manners said information provided in the booklet provided "the other side" of the debate which was being skewed by a "one-sided presentation" by the government.
Among the booklet's claims are that recycled water can kill people, alter behaviour, reduce sperm counts, cause infertility among couples and trigger a doubling in liver cancer rates.
The booklet, Think before you agree to drink - Is sewage a source of drinking water?, also claims recycled water created "gender bender" fish and made male lambs "start behaving like females".
But the scientists expressed surprise that their research had been used to back up such claims.
University of Queensland Professor of Developmental Biology Professor Peter Koopman, who is quoted in the book, said his research had been taken out of context and he had been unaware his name appeared in the booklet until told by journalists.
The book says Prof Koopman's work shows recycled water could lead to a rise in infertility rates.
"It's very intriguing," Professor Koopman told ABC radio.
"I was interviewed some time ago about the subject of increasing rates of infertility but the connection with recycled water was not apparent and it still isn't apparent to me.
"We haven't had recycled water and therefore the drop in fertility can have nothing to do with recycled water."
He said no research whatsoever had been done linking the use of recycled water to dropping infertility rates.
Acting Premier Anna Bligh said the scientific misinformation was "further evidence that this material is mischief making".
"It has very, very little relationship if any to science," she said.
"If Snow Manners has got $300,000 or $400,000 to pour down the drain that's his business, but I don't think that the people of south-east Queensland will be swayed by this sort of scaremongering."
Recycled water is used for drinking in many advanced countries, without any evidence of harmful effects.
Can I suggest that a copy of the booklet be forwarded to each of the scientists and other eminent people quoted in the book, or whose research has been presented as evidence against recycling?
Was permission from these people to use their material in this way sought, and granted?
How many other people/scientists quoted in the booklet would come out to state that their words and work have been taken out of context and misinterpreted and misrepresented?
The authors of the booklet may find themselves in a bit of bother with possible legal action being brought against them for defamation.
Now that would be interesting!
njta, you must be one hell of a bush lawyer if you think you can sue someone for defamation for reprinting your own statement.
Recycled water is used for drinking in many advanced countries, without any evidence of harmful effects says Anna Bligh
She just can't name any
I'm still waiting for peer reviewed studies on the long-term safety of drinking recycled water.
I've been waiting since mid-2005.
Jeremy,
You’ll find quite a number of them referenced in the back of the document that you can access from here.
For places where recyled water is used safely, you'll find a few described here
Still looking for the long-term study on humans which shows that recycled water has no long-term harmful effects. Been asking since mid-2005 in Toowoomba and Brisbane and no-one can provide it. What they can provide is a couple of examples of potable reuse overseas and short experiments on fish in Singapore. Not really what I want. If governments wish people to adopt recycled water for drinking, they should show that it is safe. It is not up to individuals to show it is not safe.
Jeremy,
If you go to the link I posted above, read the report and you will find some peer-reviewed epidemiologic studies (on humans) from California.
I'm sorry you had to wait so long. I don't think you've asked me before?
Read it - it's not a long-term study. No-one can provide one.
Thanks for taking the time to read the report Jeremy,
As you will have observed, it is a review of numerous studies including some long term studies from California.
How long do you think is a reasonable study? Do you think it would be of any value? Could you control such a study? Do you think it would be sensitive enough to pick up the 1-in a million additional cancer risks that we currently seek to identify for water safety standards?
I appreciate your willingness to engage in such a discussion.
Stuart
One which involves a similar scheme to Beattie's would be a start - putting up to 100% recycled water into a city's main dam and then piping it to homes and businesses.
Hi Stuart,
This water 'crisis' has gotten me very interested in this Reverse Osmosis technology. In fact, you can get little RO units for the home. They seem to be common in the States. I'm looking into it.
Anyway, I want to ask you about something else. My understanding is that RO units have an effluent stream containing all of the concentrated nasties. Do you have any information about the expected recovery or yield of fresh water from a m3 of untreated water for the kind of system proposed for Brisbane? Also, what do they do with that waste stream?
Cheers.
Hi Mark,
Yes, the management of the membrane ‘concentrate’ is a key issue and often a limiting factor for the use of such treatment processes for both water recycling and desalination.
The ‘recovery’ or ‘efficiency’ depends on a number of factors including the initial water quality and how hard the membranes are pushed. In practice, about 80% of the water is typically recovered for reverse osmosis treatment of municipal effluent. For seawater desalination its typically more like 50% and brackish water desalination it can be anywhere in between.
I don’t know the precise engineering plans for the Western Corridor scheme. However, some proportion of the water coming through the plant would be advanced-treated and recycled. The remainder will either continue to be discharged via the existing ocean outfall or used for lower-quality uses.
A likely solution for the concentrate is simply to return it to front of the sewage treatment plant where it would be mixed with the incoming sewage and then undergo treatment again. Alternatively it could be directly blended with the water being discharged via the outfall or being used for lower-quality uses.
Depending on the relative volumes of the various streams, the returned concentrate may or may not have a significant impact on increasing the overall salt concentration in the discharged or lower-quality reused water.
There are a number of current research projects investigating beneficial uses of membrane concentrates (such as recovering various chemicals from them), but no such practices are really at an implementable stage of development just yet.
Thanks for your comments Stuart.
But that last point is an interesting thought. Our sewage has so much chemical contaminants that it could be worth mining!
Presumably there has to be some outlet for the water because if you recycle it, the nasties will just accumulate.
It's interesting, though, that RO can be used to make water out of sea water, brackish water and probably storm water too. I wonder why they considered sewage effluent to be a better feed material for the process. Any ideas?
Cheers.
G’day Mark,
Certainly there are things in sewage (apart from the water) which would be worth mining if we could do it relatively efficiently. The most obvious is the absolutely essential agricultural nutrient, phosphorus. The planet’s available phosphorus is rapidly diminishing and severe shortages are expected before the end of this century.
Our current practice is to mine phosphate and apply it to agricultural soils where it is taken up in food. We then ship the food to cities (most of the large ones are on the coast) and eventually discharge the phosphorus via our toilets and sewers into the ocean. Some of the phosphorous is recovered as sewage sludge, but a significant proportion of it is lost.
I suspect that within a decade or two, this will be recognised as an urgent enough problem that serious efforts will be made to recover most of the phosphorus from our sewage (call me a quack now if you want to…).
Yes, as you suggest there needs to be an outlet for the water in order to prevent the accumulation of non-degradable chemicals. This is the proportion described above that would be discharged via the ocean outfall or reused for a lower-quality application.
Actually we do use water from all of the sources you have listed. Australia has one of the largest seawater desalination plants in the world (Perth) and is actively building more (Sydney, Gold Coast…). We also have many brackish groundwater desalination plants, particularly in inland regions of Queensland and Western Australia. Storm water is also used in many places (eg. most of our current potable water supplies!), but storm water collected from urban areas has a number of difficulties that are often not recognised. One is the need for significant storage which can be complex in coastal cities. Rainwater tanks are a good solution for better utilisation of storm water. Rain water tanks are being increasingly used in Australian cities. I think you would be mistaken to think that Australian cities are focused only on recycled water.
Wow Stuart, this is an amazing blog. When do you have the time to do any science??
I am researching Snow Manners' little booklet for an assignment on propaganda and your blog appears to be an excellent resource - thanks!
I am very definitely a proponent of recycled water but I have learned more in the last hour on your blog than in the last 12mths of news media.
Mark's question about the concentrate is a good one - the extracted water has a very obvious end purpose/distribution, but with any chemical or physical process there are waste products. If the concentrate will be more concentrated as a result of extracting the water and then gets piped out to sea, surely it will be entering the ocean in stronger concentration than currently. What effect is this going to have on environments local to the outflows? I know that concentrations of agricultural wastes in river outflows in Qld are already a significant problem for the Great Barrier Reef.
My other question (this time related to my homework) is, do you know if the same TBYATD booklet has been/will be distributed to Goulburn and are they having a referendum? I found a blog which suggested it was but I was unsure about the reliability of the information and can't find another source.
Anyway, back to the homework!
cheers
Kirsten
Hello Kirsten,
Thanks for your very kind comments.
Your question regarding when do I have time to do any science is a good one, -I am aware that I need to be a bit careful about how much time I spend on this blog and am now consciously trying to avoid looking at it during work hours! It’s very much a hobby and I do need to be careful not to get carried away with it… But to be honest, for a number of the posts, I have been able to prepare them as abbreviated versions of other documents that I have been legitimately preparing as part of my work. So in some cases, there is not as much dedication as it may appear.
Furthermore, sometimes typing out a blog helps me to focus my own thoughts regarding some of the ‘big picture’ issues that scientists really should have an awareness of while we are working on comparatively nitty-gritty aspects of water management. In other words, -it helps me to keep a connection with the real world!
I share your concerns regarding the sustainable disposal of waste streams from sewage treatment plants. Of course, extracting recyclable water from sewage effluent does not increase the overall load of wastes that are discharged, but it may concentrate them. If these are discharged to the ocean without significant effective dilution, it is fair to say that the environmental impacts from more concentrated (but smaller volume) wastewater plumes have not been thoroughly studied (at least to my knowledge).
My preference would be to see an end to ocean outfalls with the beneficial reuse of all of the water and associated byproducts. This is not impossible since we already reuse biosolids (sludge) from the conventional sewage treatment processes. However, the greatest obstacle to beneficial reuse of membrane concentrates is the salinity, which limits how much can be sustainably used for irrigation (or other) purposes. As I mentioned to Mark (above), there is a lot of current research on this topic, but there remains more to be done. The opponents of indirect potable recycling in Toowoomba correctly recognised sustainable disposal of reverse osmosis brine as one of the major difficulties with that proposal.
In answer to your final question, yes, -TBYATD was distributed in Goulburn. I went along to one of the community information nights and was given a copy by some of the community members there. The booklet was handed out to willing recipients after the meeting, but I’m not sure whether it has been distributed to households. The fact that I was at the meeting and received a copy of the booklet was discussed in the comments section of a previous blog post.
There is no suggestion that Goulburn are currently planning a referendum (Toowoomba is the only place on Earth that I know of to have voted on a water supply). However, Goulburn are currently undergoing a community consultation process aimed at identifying potential solutions to the current water shortage. Some members of the Goulburn community clearly believe that the consultation process is a farce. However, I would prefer to see how it plays out before subscribing to such an opinion. It may yet prove to be a very effective and fair means of decision making. It’s too early to judge.
Good luck with your assignment. If you are willing to share it, I would be most interested to read a copy of the final product. If so, you could find my email address from the UNSW website (I’d prefer not to post it here for spam reasons!).
Hi Stuart,
That stuff about Phos makes sense. All that OMO. I was wondering what chemicals there were - It turns out that you might be able to get a variety of halogenated hydrocarbons like benzene hexachloride from effluent too (H. Shiraishi et al 2005, Biol. Mass Spectrometry 12(2) ). A little review by Brenton Nicholson (Aust Water Quality centre CRC) I found makes interesting reading for all of the chemicals you can find floating in wastewater. It’s almost obscene the qty and variety of pollutants we pour into the environment. It’s pricked my conscience a little to tell you the truth.
I agree that storage space could be a big problem preventing adoption of stormwater harvesting. But luckily, V.G. Mitchell et al. (2005, 10th international conference on urban drainage, Copenhagen) have looked specifically at the Brisbane case and state "The results of the analysis do not indicate that the space requirements places a significant limitation on the utilization of stormwater".
It would seem that we need to do more stormwater harvesting because urbanization is dramatically increasing runoff, and it would in fact be beneficial to do so in Brisbane according to Fletcher et al. (2007, Water Sci. Tech. 55(4) ), with little risk of over-harvesting.
Presumably storm water would cost less to treat to potable quality than treating Luggage Point effluent. And given that space is not an issue (assuming I’m not misinterpreting Mitchell’s work), I was still wondering why a stormwater project (for example) was not selected in the first instance instead of advanced municipal effluent treatment.
Cheers,
Thanks Mark,
I haven’t read any of the papers that you refer to, but Mitchell’s conference paper sounds very interesting. How much stormwater do they propose could be harvested in Brisbane and where do they propose to store it? Do they give any costs?
Regarding urban stormwater run-off vs treated municipal effluent: If you plan to use it for potable applications, then they both require significant further treatment. Urban stormwater runs off roads where it collects many toxic chemicals from bitumen, rubber tires, car exhaust products etc. Heavy metals such as lead and cadmium are a particular problem. I don’t agree that urban stormwater run-off would cost less to treat to a potable standard than Luggage Point effluent. Then there are the additional costs associated with harvesting and storing it.
A further difficulty with urban stormwater is that it comes intermittently, unpredictably and when you least need it (ie. when its raining). By comparison, treated municipal effluent is a very reliable, consistent supply and generally not significantly dependant on the weather. Furthermore, it can be collected from a single point source (the sewage treatment plant).
I very much agree that we should make better use of urban stormwater run-off (I'm all for it!), but I hope these comments provide some insight as to why it may not be seen as a silver bullet by all.
Hi Stuart,
I have no relative cost information - I'm just an interested layperson. But perhaps you could compare say the Singapore case. It is now famous in SEQ that they have 1% NEWater in their supply. Less famously, they source almost half of their water from urban runoff (stormwater). Perhaps you are in a better position to judge whether their NEWater process is cheaper or less complex than their stormwater reclamation process.
Doubtless raw stormwater has lower quality parameters than secondary treated effluent. Is it across the board that effluent is cleaner than filtered stormwater (as you probably should have acknowledged, most of the lead in unfiltered raw stormwater is in particulate form), or is it mostly just some of the metals? You acknowledge in your report with David Roser that contaminant concentrations in effluent is variable (page 4) so I'm surprised you raise above an equivalent problem as a negative against stormwater.
I think you would find that runoff events in the Brisbane area are more frequent than in the Wivenhoe catchment area. A typical rainy day here with 20-40 mm or rain is pretty common and often causes localized flooding but the same fall has a depressingly negligible effect on dam levels. In a prolonged drought, water is always welcome so there is not a case of not needing it when it rains. Neither is recycling via sewage a "silver bullet" in terms of guaranteed supply - if around 50% of the town water is recovered by recycling, the dams will run out half as slowly. If we don't experience the kind of heavy rains that add to the dams, recycled water runs out too.
I find it somewhat amusing that the authorities are still making up the detail of this recycling process (read it here http://www.news.com.au/couriermail/story/0,23739,21467272-952,00.html) "It has meanwhile emerged that water authorities are considering building an artificial wetland inside the Wivenhoe Dam storage area to filter recycled drinking water."
Not only is it an experiment, they're still designing it for goodness sakes. Perhaps sometime soon we will hear about how they propose to dispose of the RO concentrate without offending the fishermen.
Another interesting quote from that article: "Mr (Although I think they should have said "Professor") Bursill said recycled water should be used for drinking only as a "last resort" because of the risk of human error in treatment plants." On that, I wonder what would happen if the process failed as the good Professor hinted. Would that mean that Wivenhoe would have to be emptied to the sea? What would happen if that water ended up in the town water supply into our taps and beverages and food products? I think that could be a big problem. I hope that doesn't happen. Do water treatment plants ever fail to your knowledge?
Cheers,
Hi Stuart,
That link above should be here
Here’s another skeptical expert poo-pooing the recycled water idea. A leading microbiologist, and another Professor. An expensive option and a disease risk apparently.
Cheers,
Mark,
Thanks for your excellent comments and questions. The discussion on this blog is becoming more sophisticated all the time.
I was not intending to suggest that stormwater is necessarily a worse quality source water than secondary treated effluent, nor that secondary treated effluent is not variable in quality. I was merely trying to point out that urban stormwater run-off is not the simple panacea solution that many (most?) people naturally assume it to be. I’m no expert on Singapore, but my understanding is that the stormwater run-off they use for potable purposes is from semi-protected catchment areas, which is really just the same as the way Brisbane currently collects water in Wivenhoe dam. If you have any further information, I’d be grateful to receive it.
I certainly agree that a city cannot rely on recycling alone. Traditional catchment, urban stormwater, and even seawater desalination will have legitimate roles to play in supply diversification and assurance for many large Australian cities.
Treatment plant reliability is an issue that I have become more and more interested in. I will post something more detailed on this topic here shortly. It is also briefly discussed in the LGAQ report. To (partially) answer your question… reverse osmosis plants do occasionally fail, however when they do, the consequence is typically that no water can be produced through the system (eg. the membranes are ‘clogged’ or there is a loss of pressure in the system). No failure of a reverse osmosis treatment plant has ever resulted in the contamination of a potable water supply. Furthermore, an important design characteristic for planned indirect potable recycling schemes is the ‘multi-barrier’ approach. This means that there is sufficient redundancy built into the system that if one barrier fails for a period of time, it will not cause unacceptable risks to human health.
Yes, I am interested in Prof. Bursill’s well established position and Prof. Collignon’s recent comments. Both are highly qualified and respected in their field and their comments must be taken very seriously. Some people may be interested to note that the risks identified by these two Prof’s has nothing to do with fish changing sex, harm to unborn foetuses or testicular cancer. These Prof’s are experienced enough to recognise that the real risks in potable water supplies are the same old traditional pathogens that we currently focus our risk management on: Cryptosporidium, Giardia, and viruses.
Hi Stuart,
Some facts that I have been able to dig up re: Singapore
- Known as the Sungei Seletar - Bedok Water Scheme completed in 1986.
- Around 50% of Singapore's area is used as catchment. All suitable catchment areas have already been exploited.
- Around 45% of the catchment is urban.
- Stormwater quality from urban sources is "comparable to that from a conventional catchment" with water qualities compared here.
I read that they are able to achieve this result by careful management of the collection process through "first-flush" diversion and other unspecified "programs for strict pollution control". It might be cheaper for them to spend the money up-front to keep the incoming water as clean as possible, allowing them to use conventional treatment of the reclaimed water. This article gives some cost comparisons and their reclaimed water is about 35% cheaper than NEWater. I'm not claiming that Australians could do as good a job at keeping our environment and therefore stormwater clean, but I guess Singapore would be a good a place to learn about urban water reclaimation as any. The water quality issue could explain why the Singapore authorities ought to be as particular about cleanliness as they are renowned for.
Back to Brisbane, Stuart, could you help out with this minor controversy? This 'advance treated' stuff will be piped all the way to the back of Wivenhoe (Western Corridor scheme), and presumably a massive proportion of the capital and ongoing cost will be due to this pipework and pumping 200 km over and above the cost of the new treatment facilities. Already we have some pro-recycling members of the public arguing that this water should be added directly into the water mains, if only to save some 3% of that water that will be lost due to evaporation at the dam. Can you explain the fundamental reason why this considerable extra expense (and the loss of 3% precious water) is considered worthwhile. Obviously there must be a critically important reason for it, but I (and the guy who wants it direct in his water main) seem to have missed it. What would or could happen if that dutiful citizen got his way? Does the same necessity to pump water back to the dams extend to other kinds of recycled water (eg. RO or Multiple-effect distilled reclaimed sea water)?
Cheers,
Hi Mark,
Thanks for all of these links. I read each of them and, indeed, they were very informative about urban stormwater collection in Singapore. I agree with your conclusions.
Regarding ‘direct’ vs ‘indirect’ potable recycling of treated effluent: As you would know, ‘direct’ recycling refers to piping the water straight from the advanced water treatment plant to the potable water distributions mains. The only place where this currently occurs is Windhoek in Namibia.
In 1998, the US National Research Council (NRC) released a report, examining issues associated with potable water recycling. Their conclusion was that “planned indirect potable reuse is a viable application of reclaimed water –but only when there is careful, thorough, project-specific assessment that includes contaminant monitoring, health and safety testing, and system reliability evaluation”. However, the NRC pointed out that this conclusion did not extend to direct potable reuse. My understanding of why not was simply that the viability of direct potable reuse was not considered to have been adequately established or demonstrated by existing research or projects.
This is not to say that future direct potable recycling schemes are not viable, but that significant research and evaluation would be required first. This would come at considerable expense and cause a very large delay to any current projects.
Its also important to remember that the storage reservoir and the subsequent drinking water treatment plant are valuable components of our multi-barrier approach to water treatment. We should avoid trying to strip back such barriers for the sake of simplicity and evaporation control if possible.
In regard to your final question: No, indirect pumping back to a reservoir is not generally required for other sources with less strict quality control (ie. less stringent multiple-barrier approach). Desalinated seawater is an example. In fact, the desalination scheme that is currently under construction in Sydney will deliver the water to a major water main in Erskineville (inner city Sydney). This is an obvious advantage over having to pump recycled water over a much further distance to a storage reservoir.
Some more press coverage for TBYATD today. This one's from The Autsralian:
Words Twisted in Anti-Recycling Propaganda
Greg Roberts
The Australian
May 21, 2007
SCIENTISTS say they have been seriously misrepresented in material prepared for a campaign to undermine the Beattie Government's recycled sewage plan.
Brisbane will become the first capital to use recycled sewage for drinking by the end of next year, with recycled water to be pumped to the Wivenhoe Dam through the $1.7 billion western corridor pipeline, the biggest project of its kind in Australia.
Opponents of the plan have vowed to stop it. More than 500,000 copies of a glossy 20-page booklet -- called "Think Before You Agree to Drink" and costing $200,000 -- have been distributed in Brisbane in recent weeks.
The publication claims that liquid waste from morgues and hospitals, paints and solvents would be part of a "horrendous toxic cocktail" in the sewage to be recycled for drinking.
It claims that a large proportion of male fish changed sex through exposure to sewage pollutants, and that male lambs fed sewage sludge pellets behaved like females.
The booklet refers to what it describes as scientific studies that support the case against drinking recycled water.
However, four experts quoted in the publication have told The Australian that they in fact support the use of recycled sewage as drinking water.
Melbourne Water scientist John Poon is quoted as expressing concern about "longer-term health impacts from contaminants".
Mr Poon said the quote was taken from a long article, which indicated it was safe to drink recycled water. "They have misrepresented me by taking that comment totally out of context," he said.
University of Queensland biologist Peter Koopman is quoted as blaming pollutants for a 50per cent drop in male fertility rates over the past 50 years.
Professor Koopman said his comment had nothing to do with recycled water, which was not even available over those 50 years. "The implied link is nonsense," he said.
University of Wollongong engineer Long Duc Nghiem and CSIRO scientist Colin Creighton, who are also quoted in the brochure, said they were not opposed to drinking recycled water.
The publication was funded in part by John Dowson, a semi-retired land developer in the Darling Downs city of Toowoomba, where a referendum last June to introduce recycled water was defeated.
The campaign Mr Dowson funds is organised by Toowoomba councillor Snow Manners, who conceded that some experts quoted in the brochure may have been misrepresented. "They are all direct quotes but some may have been taken out of context," Mr Manners said.
"That is a reasonable thing to do. It is crucial that people realise recycled water is not a solution, no matter how desperate the water situation is."
Although Toowoomba residents voted against drinking recycled sewage by a large margin, they will be forced to do so anyway when the city is connected to the southeast Queensland water grid.
Hi Stuart
I posted a question on 27 March regarding the TBYATD booklet which I was researching for an assignment. You asked if I would be willing to share my report. So I'll try to track down your email address as suggested and send you a pdf. Please bear in mind that my analysis was produced for a graphic design course, not a psychology or politics course and I consider it to be a fairly light analysis. Nevertheless, you may find it of interest - although it was an ungraded assessment (still not sure what purpose that serves...), my teacher returned the comment that my report was "excellent - and enlightening!"
Thanks again for running such a great and informative blog - if only more voters would read it!
cheers
Kirsten
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