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..
5 comments:
The greed that the ACT approaches water recycling is not sustainable and un Australian. Un Australian because it totally ignores the requirements in the rest of this great country and I mean Australia not that ego centric place called Canberra. Every extra litre Canberra consumes is some one elses water supply. Canberra developent must be curtailed if it means stealing that water supply from towns down stream. The phrase recycle for sustainability is inappropriate to use in the ACT.
Hi Paulp,
I take your point and, in general, I agree with it.
The treated effluent discharged by inland towns is, in almost all-cases, water that has subsequent users downstream. When a city to decides retain this water for its own use, someone else downstream is almost certainly missing out on it. There are some extremely important issues of fairness, environmental justice and water rights that need to be closely examined here.
This was a major issue in Toowoomba, where the loss of water down Gowrie Creek (which flows into the Condamine and then Darling Rivers) was seen by many as a major disadvantage of the proposed water recycling scheme.
My own opinion is that all towns and cities have a ‘sustainable limit’ in terms of population and growth. The sustainable limits of many Australian cities may well be defined by water availability. If some cities are reaching (or have reached) their sustainable limits, we may simply have to accept it.
I spent yesterday at a workshop discussing these guidelines in Canberra. A number of people known to regular readers of this blog participated in the workshop. Lots of important issues were raised, -my only disappointment was that there was not more time to discuss some of them. But I guess I have this blog for that!
Here’s a report from the Sydney Morning Herald based on the proceedings of the yesterday’s workshop…
Recycled sewage closer to tap, within limits
Mark Metherell
Sydney Morning Herald
August 3, 2007
DRINKING recycled sewage has moved a step closer with the drafting of what are said to be the world's first national guidelines to establish standards for recycled water quality.
The draft guidelines published yesterday by the National Health and Medical Research Council provide a crucial advance in the development of recycling, water industry executives say.
A water-quality expert, David Cunliffe, said one of the significant barriers to informed discussion had been the lack of national or international guidelines on recycled water.
Dr Cunliffe, who headed the expert panel that produced the guidelines, said analysis of secondary treated sewage showed it could contain more than 500 chemicals, including pharmaceuticals, hormones, fragrances, pesticides, disinfectants and dioxins.
Extracting potable water from sewage required the removal of harmful parasites such as cryptosporidium and pathogenic bacteria and viruses, thousands of which were present in just one litre of sewage.
The draft guidelines recommend that water with a "tolerable risk", using World Health Organisation standards, should be that posing an annual risk of one case of diarrhoea per 1000 people.
The maximum allowable level of pharmaceuticals in recycled water would be one-hundredth the lowest daily dose of that normally prescribed by a doctor, and for cancer-causing compounds and steroid hormones one-thousandth the normal dose.
The standards are expected to be applied to two water recycling projects already under way or being planned in Queensland and the ACT.
Dr Cunliffe said the guidelines showed it was possible to produce safe drinking water from recycled sewage. "These guidelines show recycling water will be a big challenge. They don't make it any easier," he told the Herald. But they did provide an achievable basis for recycling water, he said.
The guidelines were a significant advance on five years ago, when the idea of recycling was hardly discussed. "Where recycling will go now in terms of volumes I cannot predict," he said.
A water supply executive, Peter Donlon, said the guidelines were a crucial development.
With the impact of water shortages being felt throughout Australia, governments would inevitably have to consider the option of recycling, he said.
However, Mr Donlon, the technical director of the Water Services Association of Australia - which represents the biggest water utilities - joined others in expressing concern about the lack of competent staff to provide round-the-clock supervision of complex technologies in which a breakdown could have disastrous, even fatal, consequences.
The Australian draft guidelines had drawn keen interest from overseas, Mr Donlon said.
Peter Collignon, a microbiologist who had criticised ACT plans for water recycling, welcomed the guidelines, although he said he would like to see more specific provisions to deal with issues such as how long the recycled water should be stored before being released into the system.
Professor Collignon also expressed concern about the presence of allergy-causing contaminants in recycled water that were hard to identify and contain but that could trigger serious problems for a small percentage of people.
Hello Stuart
Do you ever talk to Patrick Troy at ANU? He has made similar comments re urban development. What do you think the water cap will be? Will it sustain the proposed 75K houses at Stromilo? Until the water cap is defined then recycling water to potable quality may not be a solution if it gets included in the cap.
I have no formal training in water management but spent several years on contract to a large water utility reading and changing watrer meters. So I got to see alot of stuff from the coal face.
Hello Anonymous,
I’ve never spoken with Patrick Troy, but I have read some of his work and am certainly a fan.
I’m afraid I can’t answer the question about what a limiting ‘cap’ -in terms of water availability or population capacity- would be for Canberra. I wouldn’t try to put a number on it, but I think the general concept of natural resource limits can be taken for granted.
Thanks for your comment.
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