Friday, July 20, 2007

National Water Recycling Guidelines

Draft National Guidelines for Water Recycling for uses that include augmentation of drinking water supplies were released for public comment this week.

National water recycling guidelines are being developed under the auspices of the National Water Quality Management Strategy in two phases. Phase 1 was finalised in 2006 and deals with non-potable water recycling applications such as for industrial and agricultural use.

Phase 2 specifically addresses planned potable water recycling schemes and this is what was released in draft form this week. Public comment on the draft document is open until Friday 21 September 2007 and the finalised version will be available after any consequential modifications are made, -probably early 2008.

These guidelines build upon the risk management framework, pioneered in the 2004 revisions of the Australian Drinking Water Guidelines and the World Health Organisation (WHO) Guidelines for Drinking-Water Quality. As such, they provide principles and a framework for safe implementation of water supply schemes.

The guidelines are not prescriptive and thus allow for flexibility in their application to suit specific schemes. However, they espouse a number of key principles which should be adhered to by all schemes. These are:

- Protection of public health is of paramount importance and should never be compromised.

- Drinking water augmentation requires community support

- Institutional capability is required

- Recycled water systems need to include and continuously maintain robust and reliable multiple barriers

- Designers, operators and managers of schemes must have appropriate skills and training.

- System operators must be able to respond quickly and effectively to adverse monitoring signals

- System operators must maintain a personal sense of responsibility and dedication to providing consumers with safe water

- Industrial waste management programs need to be established and maintained

- All schemes must be subject to regulatory surveillance

- The greatest risks to consumers of drinking water are pathogenic microorganisms; protection of water sources and treatment are of paramount importance and should never be compromised

- Any sudden or extreme change in water quality, flow or environmental conditions (eg extreme rainfall or flooding) should arouse suspicion that drinking water might be contaminated

It can be inferred that until a water authority is able to competently sign-off on each of these key principles, they are not ready to initiate operation of a safe potable water recycling scheme in compliance with the national guidelines.

While system management is the focus of the risk-based approach for protecting public health, the guidelines do provide tables of health-based water quality targets for pathogenic (disease causing) organisms and toxic chemicals. This arrangement is consistent with the Australian and WHO drinking water guidelines mentioned above.

Water quality targets for pathogens are based on ‘Disability Adjusted Life Years’ (DALYs) and targets for chemicals are based on acute and (predominantly) chronic toxicity. The concepts of DALYs, acute chemical toxicity and chronic chemical toxicity are a little too much detail for the current post. However, they are extremely important in understanding the way in which we assess and manage risks associated with water quality. Accordingly, I would like to deal with each of them in some detail further down the track.

A further important component is the management (or prevention) of ‘hazardous events’, which would lead to increased exposure risks. The now well-established qualitative risk matrix, incorporating considerations of ‘likelihood’ and ‘consequences’, has been retained to assist for this purpose.

Given that the guidelines are currently on display for public comment, it is a worthwhile exercise for people to put some time aside to read through them in some detail. The details for public submissions are available from here. And of course, I’d also be interested to know what you reckon..

Thursday, July 19, 2007

Canberra Expert Panel on Health Report

As regular readers would know, the ACT has been considering the development of a planned indirect potable water recycling scheme under the banner Water2WATER (I’m not sure what the selection of uppercase and lowercase letters is supposed to imply, -any ideas?).

An Expert Panel on Health was appointed to oversee the planning including the consideration of submissions which it may receive from organisations or individuals. The Panel released an ‘issues paper’ back in May, at which we took a brief look at that time.

This month they have released their final report titled: “Public Health and Safety in relation to Water Purification for Drinking Water Supplies - Advice to the Chief Minister of the ACT and the ACT Government on the health and public safety of the Water2WATER proposal”.

It seems that the committee have thrown their support behind a high-pressure membrane-based treatment system. They appear to have dismissed the alternative treatment schemes (which are used in other inland cities) incorporating such technologies as ozonation and biological activated carbon filtration (BAC).

The Executive Summary is plagiarised below. You can download the full report from here. I’d be grateful to receive your thoughts via the usual means...

Executive Summary

This report has been prepared as the advice to the Chief Minister of the Australian Capital Territory (ACT) and the ACT Government on the public health and safety aspects of ACTEW’s Water2WATER proposal. This proposal is for the installation of a modern day membrane-based (micro or ultrafiltration followed by reverse osmosis) water purification plant (WPP), followed by wetlands and an enlarged Cotter Reservoir, to access water from the Lower Molonglo Water Quality Control Centre (LMWQCC) effluent for the supplementation of the drinking water supply for Canberra and area.

The Terms of Reference for the Expert Panel on Health (the Panel) focus on the capability of the proposed treatment system to produce a purified water that complies with the quality specified in the 2004 Australian Drinking Water Guidelines (ADWG). This has been extended by the Panel to include the new draft 2007 Australian Guidelines for Water Recycling - augmentation of drinking water supplies (AGWR) which set out a more rigorous and extensive set of guidelines for this purpose.

While the Panel has examined the information, provided by ACTEW on the Water2WATER proposal, it has also considered the context in which this proposal is made. The effect of the current drought and likely impact of climate change on rainfall make the enhancement of Canberra’s water resources a necessity. The provision of a secure water supply in an urban area is a first priority for public health, for sanitation and for drinking water supply. The Water2WATER proposal provides one alternative mechanism for ensuring water security, based on the reliability of supply of water from the LMWQCC.

A prerequisite for the Panel’s work is that public health and safety must not be compromised at all by the Water2WATER proposal.

The Panel has reviewed the levels of treatment expected from the proposed WPP and the likely quality of purified water produced. It has assessed the level of risk and has suggested requirements for ACTEW to monitor and manage any residual risk.

The community consultation program has been examined and evaluated, and the community response assessed.

The process and criteria by which the Panel evaluated health risk and its management in safe drinking water supply is explained. Risk is inherent in life, and drinking water guidelines are determined on the basis of acceptable or tolerable risk.

The current Canberra water supply is described, including the raw water quality obtained from the Cotter River, Queanbeyan River and Murrumbidgee River. Only the Murrumbidgee water is supplied directly into the Canberra supply after treatment at Mt. Stromlo Water Treatment Plant (WTP). This plant was constructed in 2004, following the reduction in water quality from the Cotter River after the bushfires. It has capability for handling turbid water from the Cotter or the Murrumbidgee through flocculation and dissolved air flotation, dual medium filtration, chlorine disinfection and is currently being fitted with UV disinfection to further reduce the risk of Cryptosporidium entering the drinking water supply.

The Mt. Stromlo WTP forms the last safety barrier of the Water2WATER proposal, as it treats the water from the present Cotter Reservoir, and from any future enlarged Cotter Reservoir. It provides drinking water for the whole of Canberra if needed and its operation is carried out in terms of an all-encompassing, third party certified, Hazard Analysis and Critical Control Point (HACCP) Plan that covers the drinking water supply system in Canberra.

The LMWQCC handles 90% of Canberra’s wastewater, which is processed, disinfected and discharged into the Molonglo River upstream of the junction with the Murrumbidgee. The plant is a highly effective operation, removing solid and suspended material, pathogens, degradable organic compounds, phosphorus and a large proportion of nitrogen. The discharge water easily meets all guidelines imposed by the EPA. The present monitoring of the wastewater discharged is described in detail in this report, which includes frequent measurement of major components including faecal organisms, and less frequent measurement of such possible contaminants as pesticides and organic chemicals.

Prior to detailed design of a WPP using this source water from LMWQCC, it is essential to considerably extend the monitoring program to include endocrine disrupting compounds (EDCs), pharmaceutical products and more disinfection by-products. It is also necessary to monitor for a range of possible pathogens, including helminths, protozoa, bacteria and viruses. The LMWQCC is the first barrier in the Water2WATER system, which removes the bulk of wastewater contaminants and infectious organisms, and as such it must be protected through a diligent and comprehensive trade waste or source control plan. This latter plan must address all trade waste generated in Canberra and which are discharged to sewer and hence gain access to the LMWQCC.

HACCP accreditation for both Trade Waste control and the LMWQCC are required and this must also be incorporated into the current drinking water proposal to ensure that an integrated HACCP plan is in place for the entire Water2WATER project.

The initial Water2WATER proposal presented to the Panel comprised three alternative treatment trains. One is the reverse osmosis-based (RO) train, and the other two trains rely on ozone/biological activated carbon (BAC). There are fundamental differences between these two approaches in relation to salt, nutrient and organic carbon removal.

In a RO treatment train the salt is separated into a brine stream, distinct from the purified water stream. Only the purified water proceeds into the wetlands and reservoir, therefore not affecting the salt content of the reservoir or the drinking water. However, in the ozone/BAC treatment train, while the pathogens and organic constituents of the water are removed, salts pass unaltered into the output stream. This would increase the salinity of the reservoir water and therefore the drinking water to an unacceptable level.

Further, the two ozone/BAC treatment trains do not achieve the levels of removal of nutrients and organic carbon that are achieved in the RO treatment train, and the Panel therefore recommends that these two treatment trains are not considered further in this proposal.

The proposed treatment train, incorporating reverse osmosis, employs, as first step, microfiltration/ultrafiltration for removal of fine particles, protozoa, bacteria and some viruses. This is followed by RO for removal of salts, larger organic molecules and viruses, then ultraviolet light plus hydrogen peroxide (referred to as the Advanced Oxidation Process) for oxidative destruction of residual viruses and organic chemicals.

Operation elsewhere has demonstrated that the reduction in pathogens and chemical contaminants of all types in this RO-based treatment system well exceeds the requirements for drinking water augmentation. The Panel understands that the operational characteristics of this system will be evaluated in a pilot plant in Canberra, prior to final approval of the Water2Water proposal.

The purified water produced by the WPP will be pumped up to the Cotter catchment, and discharged into shallow wetlands. The Panel consider that the main benefit from this will be temperature equalization with the environment, reducing hydraulic streaming in the Cotter Reservoir. Some reduction in any residual nutrients and pathogens may also result, depending on the overall biological and temperature environment of the wetland. The Panel also noted that pathogens may also be introduced from the fauna of the wetland, as occurs widely in nature. Following the wetland the proposal is for the purified water to flow into the Cotter Reservoir. The Panel consider that it is an essential part of the overall proposal to enlarge the Cotter Reservoir, to provide an effective barrier in the supply system. This adds a safety component that cannot be provided by the current reservoir. Without the enlargement the retention time in the small Cotter Reservoir would be short, and the operating limitations on the current reservoir would result in the purified water running over the spillway during periods of rain.

The Panel notes that the purified water entering the Cotter Reservoir will still contain residual levels of nitrate and phosphate and as a result there could be an increase in the concentration of these two nutrients in the water in the Cotter Reservoir. It recommends that this potential increase should be modelled and if there is a likelihood of the increase causing toxic cyanobacterial blooms in the reservoir, then remedial action will be necessary. This remedial action can be modification of the LMWQCC to further reduce nitrogen and phosphate in the feedwater to the WPP and/or the modification of the Mt Stromlo WTP to use powdered activated carbon in the water treatment process in instances when cyanobacterial outbreaks are experienced in the Reservoir.

Risk management of drinking water supply systems using purified water from wastewater sources is a key component of ensuring public health and safety. Such processes inherently carry higher levels of risk, due to the prevalence of pathogens and complex chemicals in untreated wastewater. Acute health effects would be readily observed as outbreaks of disease. Any chronic health effects would be more difficult to measure as they would not be immediately detectable, requiring epidemiological analysis between otherwise comparable populations or comparison over sufficiently long time spans.

Epidemiological investigations to date of populations consuming drinking water augmented with purified water have not shown any increase in gastrointestinal disease.

An on-going study of water-borne infectious disease in Canberra would be a valuable monitoring component of the consequences of drinking water augmentation with purified recycled water.

While microbial pathogens are a major concern, the monitoring of pharmaceuticals and their products and natural and synthetic endocrine disruptors in purified water is also essential. Health outcome monitoring is also required, including on-going assessment of community rates of cancer and birth defects from existing population-based data sets.

The Panel notes that with the treatment train proposed by ACTEW and with appropriate levels of operational monitoring and management, along with operator training and skills at the level recommended by the Panel, the quality of purified water that is transferred to the Cotter Reservoir will comply with all the health related guidelines of both the 2004 ADWG and the draft 2007 AGWR.

In addition, the Panel notes that the 2007 draft AGWR states that a treatment train with a configuration as proposed by ACTEW will produce a purified water that complies with the health related guideline values – for both acute and chronic parameters.

Community views on the Water2WATER proposal were assessed during the ACTEW consultation process and the consultants will provide a detailed report to ACTEW. The largest single route of community access to information was the ACTEW website, with 4429 hits. Community forums, briefings and displays recorded 2441 contacts.

The Panel received only two formal written submissions, from Engineers Australia and from Professor Peter Collignon. Engineers Australia argued for the expeditious securing of improved water resources for Canberra, with cost-benefit analysis of alternatives. They suggest that a risk management plan for Water2WATER should be made available prior to the project being agreed. The detailed submission is available on the website

The submission from Professor Collignon raised concerns that ‘recycling water from sewage into drinking water is a high risk procedure’ and that it should only be undertaken as a last resort. He raised concern about adding recycled water into the small Cotter Reservoir, which would mean that the proposal is effectively a direct potable recycling scheme. His full submission is available as above.

The Panel also received e-mails expressing concerns over the Water2WATER proposal ranging from outright opposition to concerns about human error and equipment failures.

Overall only a small proportion of the Canberra community actively participated in the community consultation process despite a wide range of mechanisms to do so.

Community views that were obtained by random contact and by surveys tended to be positive or neutral to Water2WATER, compared to the negative viewpoints of those who submitted their views through e-mail, letters or submissions.

On the basis of all the available information it appears reasonable to conclude that the majority of the community are not greatly concerned with the Water2WATER proposal.

Meanwhile, the community has also clearly communicated a desire for a more detailed investigation of other options for securing Canberra’s water supply.

The Panel recommends that an on-going community engagement process take place if the Water2WATER proposal is adopted. This will allow for more detailed information to be made available to the public, and a long-term collaborative engagement and participation of the public in the development of the proposal.

Overall, at present there is qualified support within the community for the use of nonpotable and potable recycled water. However, some concerns have been raised about health and safety issues of the current ACTEW Water2WATER proposal. These require sufficient time and resources to be fully addressed. The community recognises the need for the ACT Government to act expeditiously in securing the future water supply, but urges fuller investigation of all options for securing sustainable water for the future.

The Panel considers that a reverse osmosis-based water purification plant is feasible as a method of increasing the water supply for Canberra, subject to stringent health and safety requirements being met as set out in the draft AGWR and the approval of ACT Health as the regulatory body responsible.

The Panel recommends that:

1. ACTEW only proceed to continue investigation into a dual membrane Water Purification Plant (WPP) and that the alternative treatment train using ozone and biologically activated carbon not be considered further, due to the salt, nutrient and organic carbon loads entering the drinking water supply if this method of treatment were to be used;
2. The lower Cotter Reservoir be enlarged and the Panel notes the intention to construct this simultaneously with the water purification plant and ancillaries;
3. An extensive monitoring program be undertaken at the Lower Molonglo Water Quality Control Centre (LMWQCC) on the influent (water entering the system) and effluent (water leaving the system) concentrations of microorganisms and contaminants of concern prior to detailed design of the purification plant;
4. ACTEW provide a Recycled Water Management Plan that includes the following information before the process is commissioned:
o The staffing levels proposed for the new plant;
o The level of training that the plant operators will have undergone prior to plant commissioning;
o The means by which the operation of each of the stages of treatment in the WPP is monitored and maintained at the optimum level (e.g. where relevant, details of membrane integrity testing, specialised on-line instruments etc);
o An approved Hazard Analysis and Critical Control Point (HACCP) Plan that shows the likely Critical Control Points (CCPs) for the various stages and barriers in the WPP, together with ‘action’ and ‘shutdown’ values; and
o An integrated Drinking Water HACCP plan that incorporates the Plans for the LMWQCC, the WPP and for the regulation and control of trade wastes that enter the sewer;
5. The WPP be staffed for 24 hours/day for at least the first 5 years of its life;
6. ACTEW carry out a modelling exercise to investigate the impact of the nutrient loading in the purified water on the water quality in the enlarged Cotter Reservoir;
7. An ongoing community engagement process take place if the Water2WATER proposal is adopted. This would allow for more detailed information to be made available to the community and to begin developing mechanisms for a longer term collaborative engagement approach in which the community can become partners in decision-making processes; and
8. Community consultation and engagement be incorporated into and inform all stages of future water security initiatives including the planning, design, implementation and management stages of specific projects. This would encourage a system of water stewardship that places a priority on partnerships between the community and water authorities.

Sunday, July 08, 2007

Desal Brine Disposal

Seawater desalination is clearly set to become a major component of potable water supply for many of Australia’s largest cities. Perth already has a large plant with capacity to supply 17% of the city’s needs and recently announced plans for a second plant of similar size. A smaller plant is under construction at Tugan and will contribute to water supplies for South East Queensland. Sydney has recently begun constructing a plant at Kurnell. Melbourne and Adelaide also have fairly definite plans.

Like all potential new water supplies, there are serious economic, social and environmental issues that should be carefully addressed and managed. Among the major environmental issues for seawater desalination is the need to sustainably manage the discharge of membrane ‘concentrate’ or brine.

Australian seawater desalination plants rely on a treatment process called reverse osmosis. Most regular readers are relatively familiar with the concept of reverse osmosis, but a general refresher is available from an earlier post. The process relies on forcing water through a very tight membrane. Usually about 50% of the water is passed through the membrane, leaving the vast majority of salt behind in the remaining 50% of the water. The desalinated water that is passed through the membrane is known as the ‘permeate’ and becomes the usable water supply. The remaining water, which now contains double the concentration of salt, is called ‘concentrate’, ‘membrane reject’ or ‘brine’. The volume of brine produced is roughly equivalent to the volume of purified water produced and needs to be disposed of.

In inland areas, where brackish groundwater may be desalinated, the need to dispose brine is the major limiting factor preventing wider implementation of membrane-based desalination. In coastal areas, the solution is normally just to discharge the brine back to where it came from. This may sound simple, but there are complications.

Australia has plenty of sewage ocean outfalls and plenty of experience in designing and operating them. Treated sewage is much less salty than seawater and often slightly warmer. So the solution has been to discharge the effluent via an outfall in as deep water as possible. Because the effluent is less salty (and often warmer) than seawater, it is less dense. Being less dense, it immediately begins to rise towards the surface, gradually dispersing and mixing with the ambient water as it does so. The more it mixes, the closer the density becomes to the ambient water. Ideally, the densities of the two waters will be roughly equalised before the plume reaches the surface and excellent mixing can be easily achieved.

But desalination brine is different to regular sewage outfalls. Because it is contains roughly twice the concentration of seawater, it is more dense, rather than less dense, than seawater. So instead of rising and dispersing, it naturally sinks towards the seabed and flows along deep ocean channels. This severely restricts the amount of mixing and can result in a ‘hypersaline’ layer of water on the seabed. The major concern is the effect that this may have on important seagrass habitats and benthic organisms. The issue is succinctly illustrated in the following image, which I borrowed from the "Ecological Assessment of the Effects of Discharge of Seawater Concentrate from the Perth Seawater Desalination Plant on Cockburn Sound", prepared by D.A. Lord & Associates Pty Ltd (2005).

The Perth desalination plant ecological assessment determined that all of the information available would indicate that the anticipated well-dispersed changes in salinity should have no deleterious impacts on marine fauna, including the sessile benthic fauna, of Cockburn Sound. However, the assessment did conclude that the concentrate discharge may have a minor effect on reducing high dissolved oxygen levels under conditions of normal mixing, which may have ecological implications. This reduced dissolved oxygen is assumed to result from increased stratification due to brine plume density. This stratification may reduce vertical mixing, which would otherwise relieve natural oxygen depletion (caused by respiration) in deep areas.

A marine ecological assessment for the Sydney desalination plant was undertaken by The Ecology Lab for GHD on behalf of Sydney Water Corporation. The authors reported that “no studies on the effects of toxicants in desalination plant discharge on benthic communities or species have been found to date” and that “the response of fish, fish larvae and other planktonic biota to fronts or plumes of concentrated seawater is also unknown”. The authors expected that “larger, mobile biota such as fish are likely to be able to avoid the zone of higher salinity in the immediate area of the discharge, but smaller invertebrates and some species of fish living in or near reefs and bottom sediments would be unable to escape its influence”. They concluded that “because the dense, hypersaline plume will tend to sink and disperse slowly, biota likely to be affected are bottom-dwelling or non-mobile species that live on or are physically attached to the reef. These include fan corals, sponges, stalked and sessile ascidians, anemones and attached algae. Little, if any information is available on the salinity tolerances of these species or their responses to chemicals contained in the discharge plume”.

The Ecology Lab suggested that further assessments should be undertaken:

“Because no specific information can be found on the effects of discharge for desalination plants on benthic or planktonic communities, it is essential that reef assemblages at Kurnell exposed to the plume are monitored and that toxicity tests be done using seawater concentrate surrogates on local species. Species tested should include members of benthic and planktonic communities known to be present in the area. Monitoring could involve sampling of sessile organisms (i.e. algae, attached invertebrates), large mobile benthic invertebrates (e.g. abalone, sea urchins and turban shells) and fish. Divers could sample assemblages of algae and sessile and mobile invertebrates using a combination of photoquadrats and random transects along the seafloor. Photoquadrats could be used to monitor any small-scale changes to assemblages of sessile fauna. Divers could monitor abundances of large, mobile, benthic invertebrates by counting them in fixed-length transects. Divers could sample fish using underwater video or underwater visual counts (UVCs). The most suitable method would be determined by pilot studies.”

Logically, more research has been undertaken in areas that have been considerably more impacted by seawater desalination brines such as the Mediterranean Sea, Red Sea, and Persian Gulf. In particular, Mediterranean Posidonia grasslands and their associated ecosystems appear to be highly sensitive to even very small increases in salinity. Furthermore, echinoderms appear to have been severely impacted in an area close to a Mediterranean desalination discharge. However, the direct applicability of these studies to Australian cases is unknown and highly questionable.

I’m not suggesting that this is an unmanageable issue. While some environmental degradation is assured, that is a decision we accept every time we build anything at all. Despite the efforts of various journalists to have me suggest on camera that desal brine “will kill everything”, this is not an issue that I want to be alarmist about. However, like everything, there are good ways and not-so-good ways of going about things. If we don’t pay close attention to our marine environments, we risk causing unnecessary damage. So let me tell you about how carefully a city can manage desal discharge if they can be bothered investing the time, money and effort.

In my opinion, the best example of how to do things properly is right here in Australia. The Perth desalination plant has probably been subject to more environmental consideration and care than any other plant anywhere. As such, it is an example that all other cities should pay careful attention to.

For the Perth desal plant, a series of models – including a one dimensional box model and three dimensional hydrodynamic models – and tests were used to ensure the plant would meet required strict mixing criteria set by the state environment agency. Increased certainty was achieved by running various scenarios and different models. Tank tests were also undertaken during the diffuser design and an expert review of the design was undertaken prior to installation.

Pilot field measurements indicated that during calm periods, near-bed dissolved oxygen levels naturally decrease in Cockburn Sound. As a result and because of the semi-enclosed nature and topography of Cockburn Sound, a detailed study was undertaken to consider the extension (if any) of any natural stratification and associated dissolved oxygen issues that may result from brine discharge. This study concluded that any additional effect on dissolved oxygen levels would be infrequent and minor. However, it recommended that because of the uncertainty of predictions for long calm periods, a monitoring program should be implemented as part of an adaptive management plan.

The two photos below belong to Water Corporation and show the continuos dissolved oxygen monitoring activities and the transmitter used to relay the data.

The Perth desalination plant outlet is 1.2 m in diameter and has a 160m long, forty port diffuser where the ports are spaced at 5 m intervals with a 0.22 m nominal port diameter, located 470 m offshore, at a depth of 10 metres, adjacent to the plant in Cockburn Sound. The diffuser incorporates a discharge angle of 60 degrees. This design was adopted with the expectation that the plume would rise to a height of 8.5 m before beginning to sink due to its elevated density. It was designed to achieve a plume thickness at the edge of the mixing zone of 2.5 m and, in the absence of ambient cross-flow, 40 m laterally from the diffuser to the edge of the mixing zone.

The operating licence for the Perth desalination plant requires that certain dissolved oxygen levels are met in order for the plant to operate. Furthermore, a minimum of 45 dilutions must be achieved at the edge of the mixing zone, defined in terms of a 50 m distance from the diffuser. Extensive real-time monitoring is currently being undertaken in Cockburn Sound for the first year of operations to ensure the model predictions are correct and that the marine habitat and fauna are protected. This includes monitoring of dissolved oxygen levels via sensors on the bed of the Sound.

Visual confirmation of the plume dispersion was achieved by the use of 52 litres of Rhodamine dye added to the plant discharge. The expulsion of the Rhodamine dye from one of the plant diffusers is shown below. The dye was reported to have billowed to within about 3 metres of the water surface before falling to the seabed and spilling along a shallow sill of the Sound towards the ocean. The experiment showed that the dye had dispersed beyond what could be visually detected within a distance of around 1.5 kilometres, -well short of a protected deeper region of Cockburn Sound about 5 kilometres from the diffuser. The environmentally benign dye experiment was first commissioned in December 2006 and repeated in April 2007 when conditions were calm. These photos were taken by (and belong to) The West Australian newspaper.

I’ll be interested to see whether other cities consider it necessary to go to such lengths to ensure the protection of their own marine environments. I also reckon a few studies on the (possible) impacts of increased salinity levels on Australian marine organisms wouldn’t go astray.

Tuesday, July 03, 2007

Sydney Desalination Protests

Community opposition and the need for adequate consultation for contentious water management plans are not limited to major dams or indirect potable water recycling schemes.

An article in today’s Sydney Morning Herald reports that residents of Sutherland Shire turned out in force today to express their opposition to the NSW Government’s plans to build a seawater desalination plant on the Kurnell peninsular.

As Sydney’s storage dams passed 53% capacity, residents were left wondering what the NSW Premier’s previously stated ‘trigger point’ of 30% was all about.

'Stop the Desal' Protest
By Dylan Welch
Sydney Morning Herald
July 3, 2007.

About a hundred Sutherland Shire residents gathered at the site of the proposed desalination plant at Kurnell earlier today, to protest its proposed opening.

Holding signs reading "water tanks not desal", "no desal, anywhere" and "crazy not critical", as well as t-shirts emblazoned with the words "desal no, recycling yes", the protesters blockaded its entrance for about an hour.

At around 8.45 security guards closed the gates and a truck, which had been attempting to leave, reversed back into the site.

The local residents had begun their protest near the corner of Captain Cook and Joseph Banks Drives, about 200 metres from the entrance to the proposed plant.

A huge dinosaur on the back of a ute, holding a sign reading "stop the project Iemma or you will become extinct like me" led the march to the site.

The people behind it were chanting, "stop the desal, save the bay."

Protest organiser Susan Davis said because dam capacity was at 50 per cent, the plant was no longer critical infrastructure.

"Put it on hold. Don't do anything until [Sydney's water levels] get to 30 per cent. We've got about two to three years' supply."

Another local resident, 11-year-old Jeremy Hiskins, said he was concerned about the effects of the plant on Botany Bay.

"The whales will die and we won't be able to fish anymore."

Alan Shorton, 64, who runs a Kurnell real estate office and has lived in the Sutherland Shire for 50 years, said he had already watched Kurnell change drastically over the last half century and was concerned what further industrial developments would do.

"We used to come out here and slide down the sand hills and now it's just turning into an industrial quagmire," he said.

At the last available reading, made on Thursday, Sydney's dam levels sat at 53.1 per cent, more than 23 per cent above the crisis point that the Iemma government had set for initiating a desalination plant.

The plant being built is also twice the size of the original proposal.

Sunday, July 01, 2007

Water Reuse & Recycling Conference

I hope readers of this blog will accept a short interruption to our normal programming for a brief blatant advertisement.

I have spent a fair chunk of my time during the last few months organising the 3rd Australian Water Association Conference on Water Reuse & Recycling. The conference will take place at the University of New South Wales during July 16-18.

While any interested person is welcome to attend, the registration fees are unfortunately clearly prohibitive for most private citizens. Accordingly, the vast majority of attendees will participate on a professional basis, -funded by their employers. No speakers are being paid to present their papers and all are required to register to attend.

The aim of the conference is to bring together researchers, regulators and practitioners in fields relevant to water reuse and recycling. I hope that we will be able to generate some productive dialogue regarding the drivers for change in water management in Australia, technical capabilities and limitations, understanding our communities, best management practices, and future research priorities. With this aim in mind, I present the following program of presentations, which we have assembled during the last few months.

Having had the privilege and honour of the role of Chair of the Scientific Committee, I have read all of the papers associated with these presentations. Accordingly, I know that there is a lot of excellent research and many extremely interesting developments to report. Undoubtedly, I will draw upon some of the papers and subsequent discussions for future blog posts. In that way, I hope that I will be able to make new information and ideas available to a wider audience.

Water Reuse & Recycling – UNSW, July 16-18, 2007

Oral Presentations

Milestones in the Reuse of Municipal Wastewater
Takashi Asano - University of California.

The State of Indirect Potable Reuse in the United States
Jorg Drewes - Colorado School of Mines.

Drinking Recycled Water – National Guidelines and Regulatory Oversight
David Cunliffe - Department of Health, South Australia.

The New ‘Class A’ for Water Recycling: Opportunity or Obstacle?
Hamish Reid - South East Water

Recycling Industrial Wastewater for Irrigation of Agriculture and Horticulture – What are the Major Risks?
Anne-Maree Boland - RM Consulting Group

Application of National Guidelines for Water Recycling 2006 to Existing Class C Recycling Schemes – Health Risk Management
Michelle Carsen - South East Water

Western Corridor Recycled Water Scheme - The largest Recycled Water Scheme in the Southern Hemisphere
Eric Owens - Veolia Water

Water Reuse for Golf Course Irrigation – A Case Study Within the Ku-ring-gai Local Government Area
Peter Davies - Ku-ring-gai Council / Michael Muston - Muston & Associates

A Review of Agricultural and Municipal Reuse (Dual-Reticulation) Schemes and Innovation in South Australia
Stephanie Rinck-Pfeiffer - United Water International

Staying Ahead of the (Recycling) Game
Stephanie Gillespie - Western Water

Sydney Water Gold Sponsor Address
Kerry Schott - Sydney Water Corporation

Recycled Water and Sustainable Urban Water Management.
Peter Dennis - Hunter Water Australia

Comparison of Risk of Unplanned Versus Planned Water Reuse Based on the National Reuse Guidelines.
Greg Leslie - University of New South Wales

How Public Information and Outreach before Consultation Can Help Improve Understanding
Rod Lehmann - CH2M HILL

Australia a Leader or Laggard in Water Laws for Recycled Water?
Jennifer McKay - University of South Australia

Communication Strategy of the Queensland Water Commission
Gerald Tooth - Queensland Water Commission

Diversity and Decentralisation for Water Cycle Management: Reflections from the Hawkesbury Water Recycling Scheme.
Roger Attwater - University of Western Sydney

Recycled Water for Drinking - What are the Necessary Pre-requisites?
Peter Donlon - Water Services Association of Australia

Indirect Potable Reuse: Identifying Factors that are of Public Concern
June Marks - Flinders University Adelaide

The Important Role of Stakeholder Communication when Delivering Recycled Water to Pimpama Coomera
Darren Hayman - Gold Coast Water

Additional Behavioural Change Methods for Building Community Acceptance for Recycled Drinking Water
Janet A Saunders - Janet Saunders Consulting

Religious, Philosophical and Environmentalist Perspectives on Potable Wastewater Reuse in South Africa
Zoƫ Wilson - University of KwaZulu Natal (South Africa)

Chemical Contaminants in Water: Can we Measure Everything?
Frederic Leusch - CRC for Water Quality and Treatment

Virus Removal – A Pivotal Element of the New Australian Guidelines for Water Recycling
Tony MacCormick - Memcor Australia

Effect of Antioestrogenic Compounds on the Total Oestrogenicity of Treated Effluents
Anu Kumar - CSIRO Land and Water

Application of Results of Endocrine Disruptor Research to the Western Sydney Recycled Water Initiative
Adam Lovell - Sydney Water Corporation

Advances in Water Recycling in Australia 2004-2007
John C Radcliffe - National Water Commission

The R&D Challenges of Water Recycling – Technical and Environmental Horizons
Jeff Foley - University of Queensland

Water Recycled in Australia: A Bench Mark for 2006
Bridget Wetherall - Earth Tech

Adapting to Climate Change with Water Savings and Water Reuse
John Anderson - Afton Water Solutions

Multiple Uses of Wastewater: A Methodology for Cost-Effective Recycling
Gayathri Mekala - University of Melbourne

The Challenges of Recycling Schemes for Non-Potable Use
Anthony Davey - Earth Tech

Risk Management of Alternative Water Sources – A Key Element for Sustainable Cities
Peter Holt - Ecological Engineering

The Reuse Dilemma-Changing the Accepted Paradigm for Reuse
Ian Reimers - North East Water (Vic).

Towards Australian Guidelines for Water Recycling Via Managed Aquifer Recharge
Peter Dillon - CSIRO Water for a Healthy Country

Managed Aquifer Recharge in the Botany Sand Aquifer – Part of the Treatment Train for Water Reuse?
Wendy Timms - University of New South Wales

Overview of 265 MLD Water Recycling Facility at Orange County California, USA
Dale Rohe - MWH Americas (USA)

Groundwater Replenishment of Very Highly Treated Wastewater to Deliver a Major Drinking Water Source for Perth
Nick Turner - Water Corporation of Western Australia

Water, Wastewater, Energy and Greenhouse Gasses in Australia’s Major Urban Systems
Steven Kenway - CSIRO Land and Water

Asset and Business Management Challenges in Implementing Urban Water Reuse
Warren Adams - MWH Australia

Critical Success Factors for Private Sector Participation: Reflections from Willunga Water Reuse Scheme, Adelaide
Ganesh Keremane - University of South Australia

Industrial Effluent – A Valuable Resource: Effluent Recycling Case Study
Chris Conway - GHD Consultants

Security Through Diversity - Deciding on potable use in the ACT
Gary Bickford - ACTEW Corporation

Adopting a Multiple Barrier Approach to Aquifer Recharge – An Example of Indirect Potable Reuse.
Chandra Mysore - Metcalf and Eddy (USA).

Operational Application of Quantitative Microbial and Chemical Risk Assessment in the Field of Water Reuse
David Roser - University of New South Wales

Quantifying Microbial Health Risks for Non-Potable Reuse of Stormwater
Susan Petterson - University of New South Wales

Hold the Salt: Innovative Treatment of RO Concentrate
Jacqueline Kepke - CH2M HILL

Risk Management and Cross-Connection Detection of a Dual Reticulation System
Michael Storey - Sydney Water Corporation

Diagnostic Analysis of the Technical Feasibility of RO Desalting of Treated Wastewater
Adva Zach-Maor - Victoria University

UV/H2O2 as a Barrier to NDMA and other Micropollutants at Bundamba and other Water Reuse Facilities – Application and Case Studies
Christian Williamson - Trojan Technologies

Why has SEQ decided to drink purified recycled water?
Ted Gardner – Queensland Natural Resources & Water

Fast-Tracking the Development of Recycled Water Schemes
Cameron Evans - Veolia Water

Assessing the Feasibility of Integrated Water Cycle Management in Coolum Ridges
Phil Selmes - Parsons Brinckerhoff

AWA Water Recycling Forum Position Paper: Water Recycling to Meet Our Water Needs
John Anderson – AWA Water Recycling Forum

Treatment of Highly Polluted Paper and Pulp Effluent using Combined Treatment Processes including a Continuous Ion Exchange Process
Thomas Dahlke - Orica Watercare

Challenge Testing of Medium Pressure UV Disinfection at a Recycled Water Plant
Mark Angles - Sydney Water Corporation

Effects of Organic Fouling on the Removal of Trace Organic Contaminants by Nanofiltration Processes
Long Nghiem - University of Wollongong

Advanced Oxidation Technologies for Removal of Micropollutants in Indirect Potable Reuse Schemes
Heather Coleman - University of New South Wales

Poster Presentations

Assessment Tools for a Sustainability Framework for the Australian Water Industry
Greg Peters – University of New South Wales

Class A+ Effluent from a Single House AWTS – Miniaturized MBR Technology
Craig Timms – Econova

Mass Spectrometric Identification of Organic Chemicals Comprising Fouling on used Reverse Osmosis Membranes
James McDonald – University of New South Wales

Membrane Bioreactors in Australia: Forecast is for Growth
Stephen Chapman – MWH Australia

Determination of Antibiotics in Wastewater for Recycling
Nhat Le-Minh – University of New South Wales

New and emerging water treatment technologies; View on Contaminant Removal Mechanism
Shubha Sudheendra - National University of Singapore

Rejection Capabilities of RO membranes to Notification-Level Chemicals and Selected Endocrine Disrupting Chemicals
Mohammad Helmy – CH2M Hill

From Pollution to Solution – Renewed Water from Contaminated Groundwater
Fred Barendregt - Kellogg, Brown & Root

Health Risk Assessment for Recycling for Replacement River Flows
Stuart Khan – University of New South Wales

Using MF-NF-RO pilot plant to produce designer recycle water for agriculture irrigation
Linda Zou - Victoria University

Exergy Analysis of Wastewater Reclamation with Reverse Osmosis
Robert Kempton, Greg Leslie, Satinder Ojha & Matthew Brannock - UNSW

Evaluation of Membrane Bioreactor Performance via Computational Fluid Dynamics Modelling: Effect of Membrane Configuration & Mixing
Matthew Brannock, Heleen De Weever, Yuan Wang & Greg Leslie - UNSW & VITO (Belgium)

Water Research at the Particles and Catalysis Research Group of Chemical Sciences and Engineering
May Lim - University of New South Wales

Workshop: Community Engagement and Indirect Potable Reuse

This will be a highly interactive workshop and expected to be of significant interest and value to all delegates.

June Marks – Flinders University
Snow Manners – Resident of Toowoomba
Amelia Loye – Queensland Water Commission
Stuart Waters – Twyford Consulting

Public Forum: Urban Water Shortages; Who is responsible for finding a solution?

An open discussion on whether large-scale or small-scale solutions can best address urban water supply shortages.

A free event and open to the public.

Field Trips

Water Reclamation and Management Scheme (WRAMS) in Sydney Olympic Park

North Head Recycled Water Membrane Bioreactor Plant at North Head STP