Friday, October 31, 2008

A controversial week in water

It has been a controversial week with at least four very negative articles about the safety of recycled water appearing in newspapers across the country.

Wednesday’s focus was Prof Patrick Troy from ANU, quoted in a high profile story in The Australian stating that “it will not be possible to remove all biologically active waste molecules from the system”.

On the same day, Narelle Towie, the science writer for News Corporation’s Perth.Now website, was quoting water experts from Perth and Melbourne calling for potable water recycling as a sustainable measure to address water shortages in those cities.

On Thursday, The Australian had a second story ready to go featuring ANU microbiologist Prof Peter Collignon. Prof Collignon had apparently told the Australian that the “Namibian capital of Windhoek, located in a desert, had the only comparable system” to that proposed for South East Queensland. I’m not sure by what criteria Peter is comparing water treatment or water recycling systems. I’d have said Windhoek was one of the least comparable schemes. This news article is particularly worth reading for the interesting comments left by readers (except for the guy trying to flog his ‘water from air’ technology…there’s always one!).

Fears were somewhat allayed for a while today after Queensland Premier Anna Bligh confirmed “absolutely that she would drink recycled sewage in Queensland's tap water”… presumably not her own words!

But the week was concluded with The West Australian’s story “Recycled sewage can’t be made safe”. The story focused on Prof Collignon’s concerns, translated for a West Australian audience: “Just say it went wrong one day in 365, what do you do when you have all that (contaminated) water in your aquifer?”

The West Australian stated that Prof Collignon’s “views were backed by Don Bursill, head of the Federal Government’s National Health and Medical Research Council water quality advisory committee, who said even if the technology worked, human error, which accounted for some 80 per cent of water-quality incidents, could not be ruled out”.

Well at least we’re all talking about recycled water. Oh... except for us here in Sydney where we apparently have more pressing issues to discus. Can’t wait to see what the weekend brings!

Wednesday, October 29, 2008

Living and breathing recycled water today

Today was one of those days where recycled water seems to permeate every aspect. I woke up early wanting to write a blog article on an urban water-themed textiles exhibition that I saw last night (more on that soon).

However, I was quickly distracted by an online news article from the Australian. The article titled ‘Recycled sewage 'will have bugs'’ quoted Prof Patrick Troy from the Australian National University (ANU) raising his concerns about the safety of recycled water. I plan to write an article examining those concerns soon too.

By 8 am I was picked up from home by a colleague for a drive out to Western Sydney to collect some water samples from a pilot-scale water recycling plant at St Marys. This is part of Sydney Water’s ‘Replacement Flows Project’, which I will also write a blog about someday!

Straight after the 9 am news, I took a phone interview with the local ABC Radio program in Ballarat, Victoria. Some members of the Ballarat community have called for a debate on indirect potable water recycling as a means for addressing the city’s water shortages. I may be exaggerating, but I think I spoke for about half an hour about the issues as I see them. I may have raised a few eyebrows by giving the opinion that reverse osmosis would not be a simple technology to implement in such a location (due to the need to dispose of the waste stream) and that I thought alternative treatment processes such as activated carbon treatment were probably more appropriate in that circumstance. I didn’t get around to discussing the likely existing value of the water (treated effluent) as it is currently used or disposed of, but clearly that will also be an important issue to consider.

Still on our way to St Mary’s I received my first of three calls for the day from Queensland. A briefing note on Patrick Troy’s comments was being prepared for Premier Anna Bligh and there was an interest in identifying the source of a figure (8 per cent) which had been quoted. I wasn’t immediately sure of the source, but was able to provide an opinion on a few other aspects of the article.

After collecting our samples from St Mary’s, I returned to my desk and sent a quick email to Patrick Troy. Troy responded that the figure was taken from a research paper that I had previously read by Queensland scientist, Andrew Watkinson. I called Andrew and ascertained that the study that was alluded to in The Australian was undertaken at an industrial water recycling plant (not one designed or managed for a potable water supply). I’ll write some more about the relevance of the findings from that study in a subsequent blog.

By the late afternoon, I read the following article from ABC news in Queensland:

Bligh says academic ill-informed on water claims
ABC Online, 29 October 2008.

Queensland Premier Anna Bligh has dismissed the credentials of an academic who has cast doubt on the safety of recycled water.

Australian National University Professor Patrick Troy says it is impossible to remove all biological waste molecules before the water is added to south-east Queensland dams next year.

Ms Bligh says she has had fresh advice from Government scientists.

"I'm very disappointed with ill-informed comments by somebody who has no expertise in the field of water treatment, from someone whose expertise is in town planning," she said.

"His claims relate specifically to current water treatment of sewage, not to the water treatment that will be done in our recycling project."

The State Government will begin pumping tertiary-treated recycled water into dams early next year.

But Professor Troy says there is no guarantee on the osmosis technique.

"Although this reverse osmosis technique is a step up, the fact remains that it's not absolutely guaranteed," he said.

"The fact is that we don't know what the long-term effect will be of the operation of these systems."

I spent the remainder of the afternoon trying to focus on a review of quantitative methods for water recycling risk assessment that I am currently preparing for the National Water Commission. But that’s another topic that I really must catch up and write a decent blog post on one of these days...

Monday, October 27, 2008

The Victorian Water Forum

A brief article from the ABC today mentions a new alliance of "Victorian protest groups" formed to lobby in favour of indirect potable water recycling (IPR) for Melbourne.

The Victorian Water Forum is made up of the Clean Ocean Foundation,Watershed Victoria, the former Your Water Your Say group and Plug the Pipeline.

As such, they appear to be comprised of an interesting and diverse group of demographics including farmers, surfers, environmentalists and concerned citizens.

The ABC article quotes the spokesperson Anton Visenger saying that:

"the best thing for Victoria would be not to have a massive desalination plant, to not take water from northern Victoria and to recycle the water that we're currently wasting and pumping out into the ocean".

Not having previously heard of one of the alliance members, -Watershed Victoria, I read through a few documents on their website and learned that they are a recently incorporated registered association who's stated aims are to:

  • Promote environmentally sustainable and socially responsible water policy in Victoria with a low carbon and economic cost.
  • Promote water policy in Victoria which reflects this state’s unique climate, natural & manmade features and the effects of impending climate change & population growth.
  • Educate Victorians about responsible water policy at an individual, regional and state level.
  • Encourage individuals, communities, businesses and governments to make positive changes towards sustainable water policy.
  • Work positively with other organizations with similar goals of responsible water policy.
  • Ensure Victorians water and water infrastructure remain in public ownership rather than costly private or publicprivate- partnership control.
  • Ensure that desalination (due to its massive energy, social, economic and environmental cost) is a last resort option, and then only as strategic supply near point of use while considering applicable planning schemes.

The Clean Ocean Foundation’s support of IPR is explicit, with a current headline on their website stating “Purified Recycled Water: The Smarter Water Option Ignored”.

I’ve become used to assuming that “protest groups” tend to be comprised of those members of our community who are opposed IPR, -not those in favour of it. So it is somewhat refreshing to be reminded that there is in-fact a diverse assortment of equally passionately held points of view.

Thursday, October 23, 2008

Finding water for Sydney

An article in today’s Sydney Morning Herald (online) reports on a speech given by NSW Premier Nathan Rees in Sydney this afternoon. In his speech, Mr Rees justified the construction of the Sydney desalination plant on the basis that the Sydney Catchment Authority (SCA) was sourcing “roughly half” of the water it supplies from the Shoalhaven catchment:

“Later in his speech, Mr Rees told the audience that Mr Iemma had warned him not to speak about something while he was water minister.
"The former premier wouldn't let me say this, but I can say it now: we transfer roughly half of our water supply each day up from the Shoalhaven River in the south.
"In February last year, in the middle of the worst drought in 100 years, if we hadn't been transferring water from that river, and if we hadn't had water restrictions on, our water supply would have been down to 7 per cent.
"Now that's a scary figure. That essentially means people are drinking mud."
He explained that it was vital for a city as large as Sydney to have a guaranteed water supply via a desalination plant.
"If we don't establish a water supply that is independent of rain, we cannot guarantee water supply.
"If you cannot guarantee water supply, you cannot guarantee the economy and if the NSW economy ... gets the wobbles, Australia gets the wobbles.
"The desalination plant enables us to tap into the world's biggest dam - the ocean."

The transfer of water from the Shoalhaven is certainly an expensive, energy-intensive and ultimately unsustainable way to provide water for Sydney. However, the extent of the transfers appears to have been somewhat exaggerated by Mr Rees and his solution simply doesn’t stack up.

A detailed water balance for the 2006/07 financial year is publically available on the Sydney Catchment Authority website (which makes Rees’ alleged gag by Iemma seem somewhat silly).

The SCA water balance shows total transfers from the Shoalhaven to the Warragamba supply system during 2006/07 to be 98 gigalitres (98,000 megalitres). By comparison, total water supplied to customers was 507 gigalitres. An additional 94 gigalitres were lost by evaporation from storages, 56 gigalitres were released under water management licences and 572 gigalitres were spilled from reservoirs or weirs.

By any reasonable calculation, the SCA supplied at least 1,229 gigalitres (507 + 94 + 56 + 572) to either people or the environment during 2006/07. Of that, 98 gigalitres came from the Shoalhaven, which accounts for about 8 per cent. Even calculated as a proportion of the amount directly supplied to customers, this is less than 20 per cent.

Admittedly, these numbers are derived from averages over the entire year and it is quite likely that the proportion supplied from the Shoalhaven during February 2007 was significantly greater. However, that’s why we have such enormous dams as Warragamba, -to allow us to buffer our water inflows and outflows over a period of years.

With Sydney’s dams currently two thirds full, if we really are transferring half our water each day from the Shoalhaven as Mr Rees has stated, he really should demand a stop to it. We currently have plenty of water, its raining cats and dogs and the Shoalhaven should run free.

Now, considering viable solutions to curb some of this pumping back in 2006/07, the NSW State Government’s answer was to build a seawater desalination plant. That plant will supply up to 90 gigalitres of water per year (that’s less than 8% of our total water supply).

Meanwhile Sydney Water discharges around 400 gigalitres of wastewater into the Pacific Ocean every year. Even capturing and reusing half of this would provide more than twice as much as is currently supplied from the Shoalhaven or is intended to be supplied by seawater desalination in the future.

So an expensive, energy-intensive seawater desalination plant may well replace an expensive, energy-intensive inter-basin water transfer to supply Sydney with about 8 per cent of our water. However, a water recycling scheme, treating water from our coastal sewage treatment plants, could actually increase the available water for Sydney, reduce ocean pollution and relieve some pressure from our already stressed natural water supplies. Just a thought...

Saturday, October 18, 2008

Ballarat Businesses Back IPR

I came across an interesting newspaper article this morning from the City of Ballarat in Victoria.

The Committee for Ballarat’, which I understand to be comprised of local community and businesses leaders is keen to investigate indirect potable water recycling (IPR) as part of a solution for the city’s water shortages.

The problem is that the Victorian Government has made a political decision not to support (planned) IPR schemes in that State. Instead, they have favoured alternative solutions for Melbourne such as the construction of Australia’s largest seawater desalination plant and a pipeline to transport water long distances from rural areas in the Goulburn Valley to the city.

I’ll be interested to follow where this story goes...

(c) Photograph by "40 years on".

Treated water: to drink or not?
The Courier
18 October 2008

THE Committee for Ballarat will be leading a push towards recycled water for the city.

The committee's Water Task Team chair Tony Chew said yesterday that recycled water could provide a long-term solution to Ballarat's water woes and discussions were needed to avert a possible crisis in the future.

He said cities such as London, Singapore and Los Angeles had all embraced recycled water and Brisbane was also scheduled to start introducing waste water to their supply next year.

"We just want Ballarat to have a sustainable supply and we think recycled water is an important component of that supply plan. And at the moment the State Government is not entertaining recycled water for Victoria and we want to open that debate," Mr Chew said.

He said Ballarat could still run dry, particularly if low rainfall levels continued in the Goulburn Catchment area which supplies the Goldfields superpipe.

"It's too late to put the infrastructure in once we're down to that critical situation," he said.

The committee plans to approach the water minister and also the premier to get the issue of recycled water back on the table.

"We will bring with us a large body of community and industry representatives, people who are concerned as I am about the long-term sustainability of this city," Mr Chew said.

"We want to get all the debates happening and hopefully get the government and community on side to accept that recycled water is a viable solution."

Recycled water has been a contentious issue across Australia, most notably in drought-stricken Toowoomba where residents voted against drinking recycled waste water in July last year.

Mr Chew said many people considered recycled water as "drinking raw sewerage", but the reality "couldn't be further from the truth".

"Where we can we will introduce factual information into this debate," he said.

Central Highlands Water chair John Barnes said although the State Government had ruled out drinking recycled water he believed there was still a case for cities such as Ballarat "sitting at the top of the catchment".

"We welcome the committee of Ballarat opening this public debate," he said.

"(But) any debate needs to be discussed in a dispassionate and balanced way."

Ballarat Mayor Stephen Jones said the idea of drinking recycled water made him "squirm a bit", but it was definitely an option.

"They do it everywhere else around the world. Why can't we do it here?" he said.

Cr Jones said the Goldfields superpipe only provided Ballarat with a short-term solution.

Wednesday, October 01, 2008

Purified Recycled Water for Drinking: The Technical Issues

After more than a year in the making, the Queensland Water Commission recently published a 270 page report titled Purified Recycled Water for Drinking: The Technical Issues.

Associate Professor Greg Leslie and I were invited to co-author Chapter 4 of the report titled ‘Advanced Water Treatment Technologies’. I’d be grateful for any feedback or questions from anyone who takes the time to read it...

Purified Recycled Water for Drinking: The Technical Issues
Table of Contents


1 Introduction and report overview
1.1 Background
Population growth and climate change
Meeting future water demands

1.1.1 Objectives of the technical papers
1.2 Synopsis of technical papers
1.2.1 Introduction to potable water treatment – Chapter 2

1.2.2 Current wastewater treatment processes – Chapter 3

1.2.3 Advanced water treatment technologies – Chapter 4

1.2.4 Risk management of chemicals in recycled water – Chapter 5

1.2.5 Management of microbial contaminants for indirect potable reuse – Chapter 6

1.2.6 Current indirect potable reuse schemes – Chapter 7

1.3 References

2 Introduction to potable water treatment
2.1 Introduction
2.2 Australian drinking water guidelines
2.3 Why treat water?
2.4 Conventional water treatment
2.4.1 Dissolved air flotation
2.5 Disinfection
2.5.1 Chlorine
2.5.2 Chloramine
2.5.3 Ozone
2.5.4 Ultraviolet disinfection
2.6 Other treatment options
2.6.1 Adsorption processes
2.6.2 Oxidation
2.6.3 Biological filtration
2.6.4 Anionic resins
2.6.5 Membrane filtration
2.7 Monitoring
2.8 Potable water treatment in south east Queensland
2.9 Conclusions
2.10 Acknowledgements
2.11 References

3 Current wastewater treatment processes
3.1 Introduction
3.1.1 Outline of this chapter
3.1.2 Compounds in wastewater
3.1.3 Overview of wastewater treatment
3.2 History of wastewater treatment
3.2.1 The need for wastewater collection and treatment
3.2.2 Early wastewater treatment methods
3.2.3 The development of secondary treatment
3.2.4 The development of tertiary treatment
3.3 Steps in wastewater treatment
3.4 Nutrient removal processes
3.4.1 Biological nitrogen removal
3.4.2 Biological phosphorus removal
3.4.3 BNR operation
3.4.4 Common BNR plant configurations
3.4.5 Developments in BNR technology
3.5 Removal of micropollutants in wastewater treatment
3.5.1 Factors affecting biological removal of micropollutants
3.5.2 Performance of micropollutant removal
3.6 Reliability of modern wastewater treatment plants
3.6.1 Reliability of WWTPs in meeting licence conditions
3.6.2 Existing and future monitoring and controls
3.6.3 Importance of source control
3.7 Treatment processes in South East Queensland
Bundamba wastewater Centre
Oxley Creek wastewater treatment plant
Gibson Island wastewater treatment plant
Luggage Point wastewater treatment plant
Goodna wastewater treatment plant
South Caboolture wastewater treatment and reclamation plants

3.8 Conclusions
3.9 References

4 Advanced water treatment technologies
4.1 Introduction
4.2 Multiple barrier approach to water treatment
4.3 Objectives of advanced water treatment process
4.4 Technologies for removal of suspended solids
4.4.1 Membrane technologies
4.4.2 Monitoring the effectiveness of membranes
4.5 Removal of dissolved chemicals
Rationale for removal of organics
Rationale for residual nutrient removal
Rationale for removal of residual salt

4.5.1 Removal technologies for dissolved chemicals
Semi-permeable membranes for reverse osmosis processes
Adsorptive treatment processes
Advanced oxidation processes
Ion Exchange processes

4.6 Disinfection Processes
Ultraviolet light

4.7 Stabilisation
Rationale for stabilisation
Addition of sodium hydroxide
Lime stabilisation

4.8 AWT processes in South East Queensland
4.9 Conclusions
4.10 Acknowledgements
4.11 References

5 Risk management of chemicals in recycled water
5.1 Introduction
5.1.1 Scope of this chapter
5.2 Risk assessment framework
5.2.1 Issue identification
5.2.2 Hazard assessment - toxicological
5.2.3 Exposure assessment
5.2.4 Risk characterisation
5.3 Risk perception and risk communication
5.3.1 The case of endocrine disruption
5.4 Assessment guidelines
5.4.1 Australian drinking water guidelines (2004)
5.4.2 enHealth Council guidelines
5.4.3 National guidelines for water recycling (2006)
5.5 Hazard assessment for chemicals
5.5.1 Recognised chemical contaminants
5.5.2 Unknown chemicals and/or complex mixtures
5.5.3 Chemicals in water
Natural and synthetic hormones
Synthetic Industrial chemicals
Pharmaceuticals and personal care products
Treatment by-products
Radiological water quality
Pesticides and heavy metals

5.5.4 Dose-response relationships
5.6 Exposure assessment
5.6.1 Measurement methods
Chemical analyses of individual compounds
Complex mixtures and detecting ‘unknown chemicals’

5.6.2 Source controls
Trade waste controls
Hospital waste

5.6.3 Removal of organic contaminants in wastewater
Fate and partitioning
Removal of selected endocrine disruptors from WWTPs in SE Queensland

5.6.4 Removal of chemicals during AWT
5.7 Risk characterisation
5.7.1 Epidemiology
Cohort (longitudinal) studies
Cross-sectional studies
Ecological studies

5.7.2 Experimental toxicology
Biomarkers of exposure and/or effect
Whole animal testing
Toxicological Studies on IPR

5.7.3 Combining observational epidemiology with experimental toxicology
5.7.4 Other methods for monitoring and assessment
Sampling techniques
Quantitative structure–activity relationship (QSAR)
Integration of chemical and bio-analytical methods

5.8 Conclusions
5.9 References
Appendix 1
List of regulated chemicals from ADWG and their identification as EDCs
Regulated pesticides from ADWG and their identification as EDCs

6 Management of microbial contaminants for indirect potable reuse
6.1 Introduction
6.2 Pathogenic microorganisms potentially present in wastewater
6.2.1 Bacteria
6.2.2 Viruses
Box 6.1 Can I get AIDS from drinking water?
6.2.3 Protozoa
6.2.4 Prions
Box 6.2 Can I get mad-cow disease from drinking water?
6.3 Removal of microorganisms from water
6.3.1 Wastewater treatment
6.3.2 Disinfection processes
6.3.3 Environmental buffer
6.3.4 Potable water treatment
6.4 Monitoring the removal of microorganisms from purified recycled water
6.5 Guidelines for water quality and microbial contaminants
6.5.1 Australian drinking water guidelines
6.5.2 National guidelines for water recycling
6.5.3 EnHealth guidelines
6.6 The management of microbial risks in water
6.6.1 Risk management in the National Guidelines for Water Recycling
6.6.2 Risk management in the enHealth guidelines
6.7 Acknowledgements
6.8 References

7 Current indirect potable reuse schemes
7.1 Introduction
7.2 United States of America
7.2.1 Upper Occoquan Sewage Authority, Northern Virginia
7.2.2 Groundwater Recharge in California
Box 71 Presence of N-nitrosodimethylamine (NDMA) in recycled water
7.2.3 Scottsdale Water Campus, Arizona
7.2.4 Gwinnett County Georgia
7.3 Singapore
7.4 Windhoek, Namibia
7.5 Veurne-Ambacht, Belgium
7.6 Berlin, Germany
7.7 United Kingdom
7.7.1 Thames River
7.7.2 Essex and Suffolk Water
7.8 Examples within Australia
7.9 Relevance to South East Queensland
7.10 Acknowledgements
7.11 References

Abbreviations and glossary

Back on the Blog

Well it has been a long time between drinks, so to speak. I haven’t posted a blog here since May and it has just turned October!

2008 has been a very busy year for me, -at work and away from it. However, running this blog has been a rewarding activity and I have missed it like an old friend. It was also a very effective way of keeping myself up-to-date with new developments at home and overseas. I feel like a have a much more balanced perspective on social attitudes and community sentiment when I am reading the blogs and receiving feedback to things I have written. So I am back on the blog with a fresh resolve to keep it active and updated.

I hope some of the friends and acquaintances that I met during the Toowoomba, Goulburn, Canberra and Brisbane debates of 2006/07 will stop in again and I hope to spark the interests of some new readers and contributors over time.