What are the hazards of recycled sewage into
drinking water?

Could it make a difference to Australia's
water shortage?

I'd like to read what other posters have to
say on this controversial topic.

Foxy,

When I first learned that sewage water was used as drinking water in places like U.K., Israel, parts of Europe, Canada and now the USA my first reaction was "Gross". Til I realised that this meant I'd been to places which used this method and obliviously drunk the water.

I don't remember anywhere downing a glass of brown water with floaties in it (which is the picture drinking sewage brought straight to my mind): - I was still here - and so were all the millions of people - old and young, babies and geriatrics - who lived in all these places.

I think, in this instance, the inhabitants of Toowoomba who voted against the planned installation were being a wee bit precious. Because, to answer to your query about the difference it could make, I guess we all worry about the water situation in Australia and know what the penalty for not taking action will be. Wringing our hands because we can't get over the Yuk factor when we have a possible solution - already operational in other places whose need for water is not at the critical stage as it is in Australia - could even perhaps be viewed by some as being irresponsible?

Accompanied by refusal by all of us to accept the current short-sighted local government irresponsibility in the matter of domestic water-tanks - not least for those who still refuse to accept the proposition of potable sewage - it possible we could be contributing to part of a solution. Right now every living creature in Aus. is part of the problem. The solution to which lies...if not in our own hands, at least in another integral portion of our anatomy.

ps: theres a wealth of information on the Web: try www.science.org.au/nova/095/095key.htm, or All About Australian Drinking Water as starting points.

How many opponents of recycled water have actually visited a dam?

They're stinking, filthy things, crawling with algae and animal crap. Then it gets treated and comes out of our tap as yummy drinking water.

All tap water is recycled sewage to some extent. The yuck factor is just being cynically manipulated for political gain.

Foxy,

An aspect of this topic came up in March 2007 on OLO in the discussion thread to the article 'What's a bone dry city worth?'. From memory the matter of xeno-estrogens was raised in a post by the article author, Peter Ravenscroft. See: http://forum.onlineopinion.com.au/thread.asp?article=5616#74547

Sancho's post, while indicating there may well be a 'natural' yuk factor applying to water from any dam, does not even begin to address the nature of the contaminants that are only likely to be contained in HUMAN sewage effluent. The 'bone dry city' of Peter Ravenscroft's article was Brisbane. Note that the xeno-estrogen contamination issue mentioned in one of the links given in that OLO post related to water reticulated in London. Romany mentions drinking water in the UK she now knows to have contained recycled effluent as if it was not a problem: perhaps not so.

Romany suggests the rejection of effluent recycling by the residents of Toowoomba in a referendum may have been a little precious. Not so. The residents were being bullied and they knew it. Their own local catchment had also already been raided for the Brisbane water supply, and they knew that too. This link will put you on the November 2006 'To Poowoomba' OLO discussion thread and might clarify why Toowoomba residents refused the use of recycled effluent as a solution to an already acute shortage: http://forum.onlineopinion.com.au/thread.asp?discussion=256#4754

This latter link indicates the nature of the business entities and political organisations that stood to benefit in the absence of any 'cynical manipulation' by the Toowoomba voters.

Overall, its a bad idea to use recycled effluent in reticulated supplies of water. This stuff should be being used for lower grade purposes, not potential cooking or drinking purposes.

Thanks for the links, and for your comments.
From what I've read
I've got to confess that I'm not to eager
to drink recycled water. It sounds like
its going to be very expensive to put in
all the safety features, and even then, its
risky. Even the scientist
who developed the Australian water safety
guide-lines says he wouldn't drink recycled
water.

Water shortages are going to be a problem, however
if recycled water could be used for irrigation and
industrial use, (not for drinking) then perhaps
this would alleviate some of the problem?

The most ridicules thing about using recycled sewage for our water supply is the fact that it requires a greater total treatment, at greater cost, in money, & power, than it takes to start with relative cleaner sea water.

It is more cost effective to desalinate sea water, than to purify sewage. There appears to be some ideology problem with some greens, who will put the extra energy into recycling sewage, but object to desalination. Perhaps, if we could work the recycling terminology in there the problem would disappear.

The cost of the recycled sewage is the other problem. THe government want full cost recovery for the stuff, which makes it too expensive to use for irrigation, & for most industrial processes. One of the main reasons for the huge increase in our power prices is that the power plant has been made to use the stuff, at a much higher price than the old mains water price they paid.

We need to get the message, to the government, that it's ok to discount the stuff, & put it to the best use, to save the the damn water for town water.

Of course, this doesn't help places like Toowoomba. It's too expensive to pump water from the coast, up to the table lands. Inland places may have to use some level of recycling, in bad droughts.

I guess my lack of objections were based on the fact that, being such a controversial factor, I would assume that no government is going to deliberately initiate schemes that weren't completely reliable. I still think that there is so much scrutiny on the whole process that programmes that were initiated would be safe.

However, what swayed me over was Hasbeens post about the cost factor. If ensuring that all risks were eradicated is indeed going to prove so costly as to make desalination or any other scheme the better option, then of course I'd opt for the most cost-effective plan.

But I do also feel strongly about the water-tank and "rain on the roof" issue as well.

Aw hell, I guess I just feel strongly that the whole issue of water isn't getting the prioritization it deserves - perhaps I'm just grasping at straws?

From up here it seems I read far more and hear far more about the petrol/oil crisis in Australia that of absolute survival: water. While I'm not for one moment saying that alternative energy isn't of extreme importance, it just seems that water is sucha basic issue that there should be a lot more being seen to be done.

Sounds nasty! With deserts growing rounding to the full, ... is the planet.

What are we going to drink... when the small mindless runs out of pathetic excuses! We have the smarts to turn all waste water from cities drains and turn it back into the land and re-green from the inside out.9 A lot of pipe lines, but guess who has the microclimate.

Its in high school form... but I would revise the talk, and pump all wast back to the middle.

We maybe to help, than stick a ban-aid, but its your world, I just live in it.

All the best.

EVO

Romany, Foxy, all
As I understand it there are several ways to recycle sewerage and criticisms against it depend on a multitude of factors depending on the technology used.
Dam or ground water qualities are similarly difficult to be absolute about.

In some cities in France and US the ground water and is has been contaminated by water escaping or released from nuclear power generation. Some surveys I’ve seen have the contaminated water spreading .

Recycling cost recovery is possibly increased by the sale of the dried waste as fertilizer.

One other factor that goes against dams is the wastage I read somewhere that a very large % of the water is subject to evaporation with the increasing temps one wonders if this might not increase substantially.

Add to that the cost and maintenance of the dam in reality dams have a finite life some longer than others. Those that are on rivers are prone to silting up the depth reduces and therefore is more prone more rapid evaporation. For these reasons an efficient dam is one that has a small foot print but large capacity (depth).

Those that are on rivers also have the problem of flow e. g. if the river dries up or ceases to flow then the dam can’t manufacture water it is a storage facility.
Many of the nasty pollutants are trapped in the mud/ silt at the bottom therefore the less water the higher the pollutant level in the water.

In one Victorian lake used to have regular speedboat / rec boat activity. When it went dry scientific tests showed that the water and the silt had high contaminant levels and had to have extra processing.

There are a myriad of other associated issues including air born pollution settling in the water PH levels etc.

Even the rain has toxic pollution that depend on where/how it’s collected etc e.g. the acid rain effecting in Canada due to winds from US industrial and motor vehicles.
Answer, drink more alcohol it might be polluted too but after the first few who cares cheers ;-)

What's the long term effects?.

I don't know what the answer is.

But, as Romany points out - water is an
issue that needs more attention. The cost
may be expensive - but what are our choices?
A two-pipe system - one for drinking water, one
for utilities? This would only work in new
developments - not in built-up areas where it
would be excessively expensive.

Under laboratory conditions and brand new treatment
facilities, there's no reason why sewage into
drinking water shouldn't work. But systems
break down with time, and all it takes is a minute
failure that may not be detected for any length of
time - that could contaminate the water system -
resulting in break-outs of various diseases.

Is it worth the risk?

Everyone is on drugs or has a disease of one sort or another. The long term unquantified risks just don't seem necessary when there's such a thing as desalination and rising water levels.

Fascinating reading, this topic.

Everyone has given me much to think about.

Obviously we must manage our water resources far better than the squandering manner of the past.

As for contaminants; human waste is (comparatively) easy to remive when compared to medicinces as Forrest mentioned and radioactivity from areas effected by nuclear accidents and waste storage leaching in water table.

If I recall my early chemistry lessons; distillation should take care of medical contaminants like xeno-estrogens. As for radiation, well I can't speak for Europe but the issue does speak volumes for Australia remaining a nuclear power free-zone.

We are being precious about recycled water - all water is recycled one way or another - it is more about perception and how to change that. And perception is one of the most difficult things for humans to change.

That old chestnut again. As one post mentions, visits to may other cities and the drinking of tap water in those without any knowledge.

London's water is said to have been through seven sets of kidneys on its way in and out of WWTPs and WTPs on its way to the tap. It's a process that is well tried and tested (and safe).

I was involved years ago in taking waste Bauxite residue, waste gypsum and sand and creating an excellent filtration system that pulled ALL microbes and nutrients out of waste water. Never used on any large scale but did demonstrate the value (once again) of using soil as a filter.

I am with SIG, there is to much medicine being flushed into the sewage systems to make it viable as drinking water. I remember when my now retired engineer brother worked solely on designing water treatment plants told me in the sixties that the chemical (meds)problem would have to change the the whole system. That time the input of natural meds was not a problem as it is now with mainly synthetics being fed to us. Let the almighty help us if we are drinking our own or somebody else's medicine. DNA changing over time will be the case. But that is exactly what we need to cull us. Great plan!

The thread shows that recycling sewage is a very complex topic.

A few ideas/comments that have not been raised:

With respect to using desalinated water for drinking, what would be the long-term effects on population health? Is there too much or too little filtering of important minerals in the process? Will it lead to mineral deficiencies in people? It would be safer to mix desal water with natural dam water to make a shandy rather than drinking straight desal.

The model water purifier is nature itself. So, any purifying system should harness, or at least mimic, nature. Make the most of natural processes such as exposure to sunlight, aeration of the water and maximise the amount of time the water is exposed to nature.

The medicines in the water supply can, with the right treatment, be turned into a valuable resource. Why flush it away into the ocean? There should be a way to reintroduce them into the water supply so that a trace dose is drunk by all in the community in the same way that fluoride is added to water or folate added to bread. If done right, it could easily reduce the cost of the cost of, and need for, a Pharmaceutical Benefits Scheme.

Youse can TELL me all you want that recycled water is safe. Someone is yet to convince me.

Really, I'm on tank water so it isn't my genetic pool you'll be risking.

It seems to me we have the technology and the abundance to use sea water. Don't we?.

StG

Do birds crap on your roof? Possums, fruit bats, etc how about dust from nearby farms with all their chemicals/hormones, dead mice, bugs leaf matter if any is true ....guess what that goes in your tank and you're probably drinking water that is at least as 'polluted' as that which comes from town water. I'd be interested to know when was the tank last internally sterilized? When was the water extensively tested by biochemists etc?

The water that leaves the processing plants are regularly tested and dosed. The equipment is regularly cleaned/sterilized etc.

In truth every thing today has been “polluted” by industry one way or the other.
Clearly the water today by and large isn’t as “pure” as it was say 50 years ago but then we don’t suffer the diseases either.

Think of it this way at least you don’t have to drink Adelaide water.
It has body and CSI are still trying to find out who's.
Have no fear you’re not going to get out of this world alive anyway…so bottoms up and stop worrying so much. :-)

I'm not a fan foxy. No matter how objectively I have looked at this issue, read different views on it I am still opposed. I am willing to be proved wrong if the safeguards were adequate but as others have said it is not just bacterial contamination but medicines, dioxins (from tampons), draino and other chemicals that go down the toilet. Are we to canvass and screen for them all? Is it even possible?

It is not that science is not capable of coming up with ways of filtering and purifying water but human error always plays a part. Shouldn't we be more concerned with why we have let Australia's population grow to a point where we have to start talking about recycling sewage.

Would you like E.Coli with that? :)

Remember, we drink less than 2% of what we use. It is household water. Buy drinking water and enjoy pre water restriction times agin.

Dear Pelican,

I'm with you on this one. I also feel that despite
all the links that I've read - as you point out,
human error does play a big part in this equation,
and I'm not comfortable in saying, "Yeah, let's do it!"

I agree we need to look at other issues - like limiting
our population intake (Ludwig's favourite theme) with
sustainability - and so on.

Sewage into drinking water? There must be other
alternatives that we can consider ...

rehctub,
I think you missed the point water is scarce and is getting scarcer.
Are you suggesting that washing dishes and clothes in contaminated water is safe? Not from what I've read.see hospitals etc.

BTW Having lived in Adelaide ie bought drinking water...been there done that. What about the poor $8 per 10 litres is a bit much for them.

Pelican,
There is no bullit proof system. Are you drinking tap water now? You don't want to know what you're probably ingesting now, from the mains pipes and your own plumbing.

More people are made ill from eating eating at home than from system failures in the water. You really should go on a tour of water works and see how little the risk actually is.

If you eat meat, fish, Poultry or vegies you have more risk of problems than drinking mains water and as previously indicated tank water is potentially more of a worry. New Scientist (I hink) has published a number studies into the above. The only reasonable conclusion is that modern life is a a series of risks. Personally I prefer the calculated ones than "a pig at a poke". the risk is trully minimal.
There was a test where people were invited to a test a dinner where the lighting changed the colour of the food. They were told one item was off. Of the 20 terted only 1 completed the meal..the food was from a top restaurant and was all good. Conclusion its all perception/conditioning/emotion. :-)

>>>Conclusion its all perception/conditioning/emotion<<<

I'm in complete agreement with Examinator on this topic. Perhaps those who are concerned should consider what they are swimming in next time they go to the local pool.

There are/will be more safeguards surrounding recycled water than exists currently with our reservoir system (which are of a high standard BTW).

While mishaps do happen, I suggest that you are more at risk in the changing rooms of the local pool than drinking recycled water.

While Examinator has already detailed this, please consider the cycle of water from evaporation through to collection to flowing out of your taps.

Just to add a little thought - think of the numbers of dead animals that wind up in dams and rivers - mmmmmmm tasty.

We take care of the tank regularly thanks examinator. 'Preciate the concern tho.

The possums, bird, bats, whatever, don't sit and prop their bums over the edge of the opening in the top of the tank and squeeze one off, examinator.

They're not on any drugs either.

examinator and Fractelle, I do see the logic in your arguments, however given there are already all of these contaminants you speak of, do we want to add even more that we have to deal with at the treatment-end?

I must admit I have drunk my share of rainwater which was no doubt filled with all sorts of bird poop and the like and have even drunk from a running stream high in the mountains (but hopefully that at least was relatively clean).

I would rather go desalination if it did not mean an inordinate amount of energy.

The next time you read of million of gallons of raw sewage, being pumped into a river, or harbour, somewhere, due to an equiptment breakdown, not noticed by the public servant responsable, for 48 hours, think if you want a public servant responsible for sewage going into dams.

The next time you hear of a spill of chemicals, or holding ponds, at some industrial plant, think if you want industry responsible for sewage going into dams.

That only leaves me that you could trust, & I won't do it.

Everyone has raised some very good points.

And I too can see the logic of examinator's
arguments. But, as it is a question of perception,
and emotion - and as I do have health problems
regarding my "gut." I'd still prefer trying
other methods first - desalination for one...

Examinator
How can you call it 'contaminated water'. That is simply scare mungering. It is currently pumped into our waterways, mainly out to sea, with full EPA approval.

You are typical of the anti recycling crowd!

Rehtcub

What drugs are you on? Whatever is in your water supply is clearly going to your head, Examinator has been arguing (effectively and logically) about why we should not fear recycled water.

The only people scaremongering here are StG and Hasbeen.

To others I politely request that you do some research into the topic - there are myriad websites available, here is a start:

http://www.waterrecycling.vic.gov.au/default.asp

BTW If you are in NSW, you have already been drinking recycled water.

Rehtcub, and others (ladies)
I'm sorry Rehtcub we appear to be talking at cross purposes I'm arguing that on a scale of 1-100 things to worry about recycled water rates perhaps 1 i.e. very low indeed.
The 'contaminated water' was in parenthesis to illustrate that while true in absolute terms it is practically speaking emotional nonsense. I have a greater chance of becoming ill from tank water than from the city tap given the difference of care taken to ensure water quality e.g. Last night a farmer on the 7.30 top the cover off a tank put his hands in and scooped some water out to drink. Great visual but how clean were his hands? He could have contaminated the whole tank.

Keep in mind Legionella bacteria occurs naturally in the dirt hence the recommendation for rubber gloves and washing hands thoroughly especially when handling natural fertilizers when in the garden (albeit a remote chance).

In water treatment plants hygiene is paramount.

In short Foxy is right the fear of recycled water is 99% in the mind of the beholder.
Outside of a good Scotch, an unwooded Collombard/chard , My home brewed Brown Ale and Special Gun Powder or Lapsang Souchong Teas replete with “contaminants” nothing is better for invigorating the soul and body than treated water. Chin Chin.

PS ladies when you invite me around for a cuppa note the list.
PPS I’m partial to bickies with savoury topping pates etc and cream cakes or scones with golden syrup and cream too. he he he (more Mephistophelean giggles. :-)

Rehtcub

What drugs are you on?
Yes, I am very sorry about that, I simply did not read all previous posts. However, I don't think water is that scarse, we just waste far to much, this is why it is short.

If we collected it rather than channeled it into our oceans we would probobly have to all build an ark.

Stormwater harvesting would solve all our water problems.

And examinator, I am 100% pro water recycling. If they think it will be unsafe to drink, then DON'T DRINK IT!

Thanks Rechtub

I agree that our first step towards ensuring a safe water supply is to improve how we collect it in the first place. For example, I question the expense of a desalination plant, when:

1. We could collect rain water more effectively before it runs into the ocean via individual catchments by industry and home.
2. The concentration of salt that would be put back into the ocean will cause environmental hazards for marine life.

However, like any move towards sustainable living there is no single answer; recycled water makes sense because it is easy to collect, local and as Examinator has explained is safe. However at the very least, recycled water can and should be used by industry leaving fresh water supplies for consumption. We need the natural minerals that come with fresh water; as has been noted distilled water is not suitable for consumption.

Grey water systems for flushing toilets, washing cars etc is yet another method of saving on fresh water.

Having lived in the Dandenong Ranges since 2001, I have watched my garden become increasingly dry. Even tree ferns that are indigenous to this area and are many years old have simply died. We are in drought. And we don't know if this drought will become the norm, therefore it makes sense to take action to conserve what does fall from the skies.

The key point in this debate is that if Australia goes down the water recycling path, it must be done carefully. This means doing objective scientific research to determine what the facts actually are in each region and situation that it's applied.

For those interested, there's a segment on Catalyst tonight (at least in the ACT) at 8pm on the ABC.

Fractelle

Sadly there is a rub with collecting grey water. If enough people collect it in a mains system if too many collect their water there won't be enough to flush the pipes and therefore the waste to the plants. This in turn would cause backups(yuk) broken pipes, disease and necessitate flushing thus negating the savings.
Septics are different.

Also sadly we do have a problem with not enough water. The Snowy hydro system is low on water and if it continues it too will run out thus causing peak black outs in Sydney and Melb.

The water in the Murray Darling system salinity levels are climbing to such a level that the water near or at the mouth is approaching sea levels. The consequences of this are likely to be catastrophic for about 5-6 million Australians immediately.
The water in the great artesian basin is now 60 feet lower than it was 10years ago...this water is fossil water.

Perth is using up its supply of fossil water to survive it can't do this indefinitely.
The oceans are becoming more saline (AWG?) and more acidic this is having effects on plankton in the Antarctic which is the base of the oceanic food chain.
The effect of this are obvious. The list goes on and on.

This is real problem we may finish up with little choice on what to drink. AWG or natural the collection of all the observable facts are too large to right themselves quickly. They are the wild card or herd of rogue bull elephants in the room. If weather patterns change over Aust as the CSIRO believes I recon we as Australians if not the world put our survival plans on steroids and speed. Remember "if there is to be panic let it be planned and organized" and I don't mean you panic there and I'll panic here. :-)

>>>The water in the great artesian basin is now 60 feet lower than it was 10years ago...this water is fossil water.<<<

I understand this. Also I agree about difficulties with grey water, but I see possibilities with ALL ways we can save water and just problems to be solved as we go along. Trouble is we haven't really started. We're still arguing, when we should be doing. Besides, Examinator, you don't have to convince me I have a reasonable background in eco-systems/environment although I no longer work in that field.

I just hope that enough people will give thought to these pages and do their own research, especially checking the source of information given that there are so many contradictory and conflicting views. I try to check for vested interests in any claim having learned from the "example" set by the tobacco lobby and their team of trained scientists.

Fractelle,
Sorry I didn't know of your background nor did I mean to demean your intelligence.
I am alway aware that others read these posts thus whileI'm talking to you I'm adding information the general public usually doesn't know.
After all it's waste water up untill now isn't something people have paid attention to...perhaps I should have address the comment to all....sorry. I guess that means I'm off your Xmas pressy list now?
:-(

Hell no - your water filter is in the mail.

One of the limitations of this type of communication is simultaneously speaking to someone you know understands your POV and providing information for people who are less well informed.

I don't think you were doubting my intelligence at all - I have people like Yabby for that.

The more I read on this subject, the more I
realise that this is a problem that we all
will have to face sooner or later. Water
shortage is something that simply won't go
away so the sooner we look at all the
options available to us, the better.

I agree with examinator - it is a matter of
perception. Of our getting our minds around
the 'poo' question. But as Fractelle has
also pointed out - we need to make a start,
and not just talk about what we're 'going' to do.
We need to act by examining all the possibilities
open to us.

There was a good overview of the whole treatment process for recycling sewage water on Catalyst this evening. It really doesn’t sound too bad.

However, that is by no means my main point of interest in this subject.

Pelican wrote on 9 March;

“Shouldn't we be more concerned with why we have let Australia's population grow to a point where we have to start talking about recycling sewage?”

This is MUCH more important than debating the recycling of sewage water versus desalination, mining groundwater, building new dams, raising the cost of water, rationing, etc.

The craziest thing in the world is happening right now. This is the fact that many people are putting a great deal of thought and energy into debating these things, while failing to even question our national and state policies of continued rapid endless population growth!!

This is whacky beyond belief. How can it even be possible that so many intelligent and highly concerned people are thinking in such a lopsided manner about this issue?

Can’t they see that recycled sewage WILL be necessary even if we develop other forms of water provision and conservation first, if the population is just going to continue to grow, or that it if we get recycled sewage in the near future, it won’t alleviate the stress on our water supplies if population growth continues, and other measures will be needed as well.

Pushing for a cap on the size of our national population and state and regional populations, especially where water is an issue, is vastly more important than debating recycled sewage, or than having or not having this increase in supply, or imposition placed upon us…whichever way you might view it.

Just a note about desalination, which I actually support. There is a problem with boron ions which are too small to be effectively removed easily. This is often why you hear the term double reverse osmosis. Boron ions from memory are 6 times more prevalent in sea water. It has quite insidious effect on the male reproductive system. This makes the idea of shandying it attractive.

The energy question is important. From my research recycling to Class A uses about 2/3 the energy of desal while Class C is about 1/3, roughly speaking.

In my area they are planning another aquifer raid. The interesting stat is that the pressure required for desal is equivalent to a water column about 270mts high to move water against the osmotic gradient. The aquifer in question will be moving water from 650mts down. It is not that hard to do the math. The water sector in Australia is currently in the top 20 of greenhouse gas generators and that is likely to increase.

The good thing about desal in no government in Australia to my knowledge has put one in or is planning to do so without sourcing close to 100% green energy credits to run it. The WA one is probably the most suss with the Emu Downs wind farm supposedly offsetting its energy use but MW for MW it doesn't stack up. Still recycling and aquifer extraction are under far less pressure, if any, to do the same.

The synergy between renewable energy and water harvesting is only just being exploited. Also membrane technology advances such as nanotechnology and aquaporins promise far less energy requirements than is currently the case.

As for drinking treated sewerage I still see not unjustified opposition to direct potable (drinking) reuse however there is far better support for indirect potable reuse i.e. shandying it in a dam or letting nature ‘massage’ it by sending it down 40 or 50 kilometres of river before extracting it. This may well prove to be a lifesaver for rivers suffering through a water stressed future.

Csteele

I fully concur with adding recycled water to dams for "letting nature ‘massage’ it. And as an aid to our depleted river systems.

However, I remain concerned with desal plants, not only for the expense and energy in running them (can this really be offset by the purchase of 'green' credits?), but the issue you raised with effective cleansing of sea water, what happens to the ultimate waste product? It is far too concentrated to dump in the marine environment. While we could obtain salt from the waste I posit that the process would produce more salt than we could effectively use. And we are still left with a toxic residue requiring effective disposal.

I guess I am a 'desal' sceptic.

Oh this thread is becoming fun! And educational.

Fractelle, in her post of Thursday 12 March 2009 at 12:07:03 PM, says:

"I try to check for vested interests in any claim ...".

If only this was the first step taken by all participants in general environmental and public utilities discussions. So much of the (generally undocumented) claim and counter-claim could then be seen for what it really is: pre-'privatisation' scaremongering, followed by 'solution-offerring' propaganda from pollies or pollie-wannabees.

Let's take the general topic of 'desalination', and apply this test.

In most cases the water to be desalinated is seawater, for it is the relatively large-scale augmentation of reticulated urban water supply that is the object of such excercises, and only seawater is an inexhaustively abundant enough source for that requirement. The 'customers' are those already connected water-rate-paying urban residents and businesses that constitute a (large) TAX base: not discretionary spenders that may withhold from purchasing, but persons and businesses that MUST pay for the 'privilege' of connection to the utility.

There are two major pathways to desalination of seawater: reverse osmosis, a process generally intimately related to proprietary membrane technology, and involving continued re-purchase of expendables; and distillation, involving non-proprietary technology and no expensive expendable components of the system.

The pollie propaganda machine misses no opportunity to emphasise that the distillation pathway is 'energy intensive', and therefore environmentally unfriendly. The pollie-wannabee propaganda machine misses no opportunity to decry desalination in general, including RO, as being environmentally damaging, all the time pushing for RO-type reprocessing of effluent water. Why? Could it be that RO is not really competitive in the long term with distillation with respect to desalination, but by stressing the buzzword 'recycling' with respect to effluent management, an opportunity to insert 'privatised' proprietary technology into servicing a captive market is not passed up.

There's no shortage of energy for distillation. We have much of it already in coal-fired power station waste heat, but that's by no means the only source.

Reduced-pressure distillation!

Forrest

Your elucidation on de-sal methods is very welcome.

My suspicions on the proposed desal plant by the Victorian government is that it is just a further step in privatising (therefore profiteering) a public and ecological necessity - humans aren't the only life forms in need of safe water.

If desalination could be achieved using secondary heat from a variety of industrial processes and I believe it is as you say, the result would be distilled water - yes or no?

If yes, could this water be added to natural resources for it to revitalised with the minerals required for consumption - the "shandying" effect as Csteele posited for recycled effluent?

Are you concerned as I am, that nothing substantial will be done towards sustainable living until a way to profit in the short term rather than the long term is found?

At the foundation of my concern is the following excerpt from 10 Myths about Sustainability (http://www.sciam.com/article.cfm?id=top-10-myths-about-sustainability):

"Myth 5: Sustainability is too expensive.
If there is an 800-pound gorilla in the room of sustainability, this myth is it. That’s because, as Gabriel observes, “there’s a grain of truth to it.” But only a grain. “It’s only true in the short term in certain circumstances,” Cortese says, “but certainly not in the long term.” The truth lies in the fact that if you already have an unsustainable system in place—a factory or a transportation system, for example, or a furnace in your house, an incandescent lightbulb in your lamp or a Hummer in your driveway—you have to spend some money up front to switch to a more sustainable technology."

Hey Fracteelle,

I think to take the pragmatic point of view one needs to ask the question would you prefer to see recycling of water at half the energy use but utilising ‘brown’ energy or desal with all of the energy being sourced from green credits? This is what we are faced with in Victoria.

If the government sticks to its promises (a big if I know) the desal plant will mean an extra 1500ML a year for a river I am fighting for down here and it will cause a big boost in green energy investment in the state.

In our area the government, Shell and the water authority have come to an agreement to recycle water from a sewerage treatment plant in the northern suburbs to be used by the refinery thus freeing up drinking water. All good stuff but without a solid commitment to use green energy credits I would rather see the desal option instead.

What to do with the hyper saline water? I had been lobbying for a plant in our area. The position was between a salt works and a sewerage farm. For the salt works to take an amount would have been ideal for them as it would have enabled them to dramatically shorten production times. The left over could then have been shandied up with the sewerage outfall water to make it closer to the salinity of the ocean. Fresh water discharged inappropriately into the marine environment can also have quite damaging effects.

To give you an ideal of the salinity levels predicted from the Wonthaggi plant, if it where all dumped into Port Phillip Bay (which takes a year to turnover all the water it holds) instead of the ocean it would be the equivalent to two weeks extra sunlight on the bay.

I am more concerned with the chemicals it discharges rather than the salinity of the water and the membrane waste issue still needs to be resolved satisfactorily.

For those who have not already made Google their friend, a paper, "Large scale Solar Desalination using Multi Effect Humidification", by Dr Alan Williams, is the top listing of a google search using the terms 'reduced pressure desalination'. Here is the link:
http://www.globalwarmingsolutions.co.uk/large_scale_solar_desalination_using_multi_effect_humidification.htm

Now, of course, I had effectively already given this link earlier in this thread, in this post to which I again link, see: http://forum.onlineopinion.com.au/thread.asp?article=5616#74547 Reading the next 12 posts in the OLO thread may give a fuller idea of the potential significance of reduced-pressure distillation as it was envisaged as applying in the then (2006) SE Queensland context of possibly RUNNING RIGHT OUT of reticulable water.

It is the very real prospect of future literal run-outs of dam water supplies (or indeed extra dam sites) that is the inherent weakness involved in opting for the recycling of effluent water, rather than that of seawater desalination, as a pathway to maintainance of adequate urban water supply in Australia. It is not just the claimed prospect of intensified drought conditions, but the ongoing immigration population boosting of these very urban centres that are already experiencing water supply problems, that increases the likelihood of such total run-outs being experienced.

There is another dimension to the use of waste heat in effecting the reduced-pressure distillation of seawater. That is in the production of concentrated brine as a corollary of distillation. This brine, piped to good solar pond locations, is not so much a disposal problem as a valuable resource. For a look at how this may have been made to work in SE Queensland, and for future renewable-based energy supply in Australia generally, see: http://forum.onlineopinion.com.au/thread.asp?discussion=495#9790

Forget about this quibble over such water being 'distilled'. Of course it is. So, effectively, by the pathway of evaporation and condensation, is rain! A red herring if ever there was one.

There does exist a non-proprietary way forward!

Many thanks Csteele & Forrest. I have much homework to do until now I have relied upon a very basic knowledge set and my own abilities for analysis.

Until I research further, what I am gleaning from your posts is that we can achieve sustainable management of water. I just want to be sure that it will achieved in a holistic sense rather than completely privatised. For example, I have complete confidence that we will solve the problems of chemically laden membrane waste.

I tend to the philosophy that essential services require government regulation. And I am worried that 'green' credits will wind up being used by the more greedy as another 'ponzi' scheme.

Hey Fractelle,

Could I commend to you the writings from Maude Barlow, a Canadian activist who was recently made a UN special advisor on water.

She also has grave and valid concerns about the privatisation of water. We were lucky enough through the efforts of one of our group to enlist her support when she was out for the Melbourne Writers Festival. Maude was kind enough to come on a tour of our river and the resultant public statements from her were a great help in securing increased environmental flows this summer.

We did agree to disagree on her assessment of desalination projects but in nearly everything else I feel Maude’s warnings about the privatisation of this essential resource are timely and not overstated.

However it is still my understanding that the plant will revert to public ownership after a period of time.
See http://www.ourwater.vic.gov.au/__data/assets/pdf_file/0015/474/Fast-Facts---Merged-September-2008.pdf

Other links for interest,

http://www.theage.com.au/environment/renewable-energy-for-northsouth-pipe-20080726-3lfa.html

http://www.theage.com.au/environment/cost-to-offset-desal-plants-carbon-footprint-hits-42m-20080615-2qzw.html

http://www.smh.com.au/news/environment/wind-farm-vow-to-power-desalination/2008/05/13/1210444436869.html

http://www.abc.net.au/news/stories/2008/06/26/2286353.htm

Happy researching. I will be doing the same with Forrest's contribution.

Thank you Csteele

It is raining steadily in the Dandenong Ranges - something of a novel event. I will be able to conduct my research to a rare symphony; the base notes drumming of rain on my iron roof, fluting trickles of water down drain pipes and the breath of the forest in open embrace to the thunder gods.

Forrest, Steele
Very informative thanks,
I very much suggest that there won't be one solution but many. Much of the early comments were based I think on the emotional 'yuk factor' or total ignorance to the real risks in proportion to others.
I guess my point Forrest is that your statements on motivation is valid for Victoria but as you also point out places like Toowoomba the options are very much reduced.
Clearly I am in no way as knowledgeable as to the specifics as both you but I do have an interest in all things survival.
Can you perhaps help me understand what I have been taught by the local water people when in Qld? (? My mum lives there and due to the dramas a while back she asked me to explains so I took myself [with the help from powers that be] to the plants and spent time learning *basically* how it was all supposed to work.)
BTW there was much fuss up there about both options being used together any thoughts/ please.
1. A Qld Shire was selling the dried processed waste for fertilizer but was stopped because of a high level of 'radio active'(?) naturally occurring (its toxic anyway.) substance that concentrates in the process. The waste is now dumped.)
If it’s too toxic to sell for gardens dumping sounds suss.
a. what is it?
b. how does it accumulate?
c. where is the research on neutralizing it?
d. do we know much about the dumping effects?

I do remember however that rain water contains more than pure water what depends on a myriad of circumstances.
I also read that there are different brands? Of reverse osmosis and that the waste is being treated for fertilizer status/ what do you know of these?

Hi examination,

The product you refer to is known as biosolids. To give a little background our water authority has been carting the wet sludge (recovered from sewerage before the wastewater is discharged into the ocean) 60kms along the highway to another treatment plant to lie in ponds then to be spread on surrounding fields within the boundary of the facility.

They are now constructing a biosolids plant. This dries the wet sludge into pellets which are safer to health and lighter for transportation. This product is to be sold to farmers for use on farmland and although there are restrictions on its use they are far less than that of wet sludge.

To digress slightly, the plant is very high in energy use, both electricity and natural gas. However when a complete energy audit is done the sums favour (only just I might add) drying as the lesser GHG producer. This is because pond drying creates methane which is a far more powerful GHG (about 20-25 times CO2 from memory) in terms of its contribution to warming. Also the road transport needed to be taken into account.

As the plant is being constructed under a PPP (public/private partnership) the owner will have to be able to make a profit on the product and so their business case must have ticked all the boxes.

Anyway the trade waste management of the water authority is critical in making biosolids viable for areas other than non consumptive ones like tree plantations etc. If your authority has been deficient in this area then your sludge may well contain significant levels of heavy metals, some that may be radioactive, which can quickly bio-accumulate via grazing cattle and into humans. Remember much of it has already had one pass at bio-accumulation to end up as sewerage in the first place.

The radiation contamination can come in many forms and be naturally occurring, indeed one significant source can be from accumulation in water filters. I assume the levels in your area have made biosolid production unviable and yes there are issues with dumping the stuff.

cont'

Cont’

You have asked how it accumulates. Think of radioactive iodine as an example spread over all the fields in a district. A dairy cow hovers up an acre of grass increasing the concentration in its own body then releasing it via its milk to be consumed by yourself. Your thyroid selectively uptakes the radioactive iodine thus a further concentration occurs. Although it is hard for the body to excrete heavy metals from the body some will end up back in the sewerage. If the biosolids ‘manufactured’ from the produce of a district are then spread over one or two fields further base concentrations will occur.

My understanding is that although there are techniques for removing heavy metals from biosolids in many cases it is just too expensive to be viable. Instead they are graded by their heavy metal content and organic pesticide content and used or disposed of accordingly.

I hope this helps.

Csteele,
Thanks I wasn't sure of what I was told in this area but your explanation rings bells.
Is this what the MMBW used to spread on their paddocks at werribee if so they graized cattle and it was next to a river and where I went fishing. Incidently I got bacterial blood poisoning from a cut foot from there too complete with 14 days in 'death central'as it was known then( Box Hill Public Hospital). That was years ago.

It seems appropriate to draw attention to the fact that this discussion can illuminate not just the issue of actual or anticipated reticulated water supply shortage and the potential for its amelioration by recycling of sewage effluent, but those associated issues of applications of renewable energy, utilization of waste heat and off-peak electricity surplus from existing coal-fired plants, climate-independent desalinated water supply, and effluent disposal into the marine environment.

The technologies associated with waste heat utilization, geothermal heat extraction, reduced-pressure seawater desalination, solar pond energy collection, engineered wetland disposal of sewage effluent, and the cultivation of oil algae, are all potentially very synergistic.

Securing of a climate-independent desalinated water supply can in the process provide a key component of the means of conversion from coal-fired electricity generation to 100% renewable energy supply, simply by conserving the saturated brines that are a by-product of the reduced-pressure desalination process, rather than viewing them as a disposal problem, which they otherwise could be.

The acquisition of adequate quantities of salt for the saturated temperature inversion layer of solar ponds is generally the major cost associated with establishment of such cost-effective solar energy collection facilities. As an example, consider the point made with respect to the SE Queensland water shortage, in this post: http://forum.onlineopinion.com.au/thread.asp?discussion=495#9790 , that, "Using only the existing pipeline to deliver seawater [inland] to Tarong, it would take around 13 years to accumulate sufficient near-saturated brine in around 560 surface Ha of solar pondage to be capable of producing solar generated electricity equivalent to the 1400 Mw generating capacity of the existing coal fired operation."

77/20!

Where does the energy come from to pump these brines and sewage effluents inland? How about from the surplus of presently off-peak largely coal-fired electricity generating capacity of the national electricity market?

It is also a good time to point out the link given by rstuart in this post to the contemporary topic 'Recycled sewage': http://forum.onlineopinion.com.au/thread.asp?discussion=2586#58291