Monday, February 19, 2007

Liverpool-Ashfield pipeline now Recycled Water pipeline

Premier Morris Iemma launched his government’s re-election campaign in Sydney yesterday. Water recycling initiatives were announced as an important component of the ALP’s strategy. Most of the initiatives -noble as they may be- were merely re-announcements of schemes previously promoted in the Government’s Metropolitan Water Plan, which was released more than a year ago.

However, the most revitalised proposal is a commitment to develop the Liverpool-to-Ashfield pipeline as a recycled water pipeline consistent with what I have previously called for on this blog. I’m hopeful that this will prove to be more than simply a re-christening, and that with careful planning it will become a highly practical piece of Sydney’s water infrastructure.

The picture below was published by The solid yellow line shows the pipeline currently under construction from Liverpool sewage treatment plant (STP) to the Ashfield sewer. The thinner orange line is the planned ‘grid link’ which is the new part of yesterday’s announcement. The dotted yellow lines are ‘potential links’, -apparently including the existing northside storage tunnel. Since the North Head STP didn’t quite fit on the map, someone seems to have made an executive decision to shift it to Mosman (who says its not a practical plan?), -or perhaps that red dot is the Taronga Zoo water recycling plant!?

I know that it would be rather naff of me to try to take any credit for Iemma’s idea, but I may just be vain enough to point out that I did energetically push the concept of facilitating recycling from the Liverpool-Ashfield pipeline a year ago, when I appeared as a witness to the NSW Parliamentary Inquiry into A Sustainable Water Supply for Sydney. While I think the opportunity is so obvious that Blind Freddy could not have missed it, the lack of enthusiasm for it (until now) has been both bewildering and frustrating. As the inquiry report stated:

4.27 Recycling treated water for agricultural purposes is considered later in this chapter. Dr Khan also notes that the infrastructure requirements of ‘large scale water reuse in Sydney’ are a key consideration of these measures [160]. Instead, Dr Khan suggests that a number of smaller treatment stations, established at intervals along the water treatment and supply route may be a more effective method of treating and supplying water for water reuse. He advised the Committee that sewage treatment plants along the Georges River, at Glenfield and at Liverpool, produce a minimum of 37 megalitres per day of secondary treated sewerage [161]. He suggests that instead of this water being reintroduced into sewers and sent to Malabar, where it is discharged into the ocean, that it could be treated to a slightly higher level and recycled:

“At the moment Sydney Water has a scheme that they are about to start implementing this year called the Southwest Sydney Sewerage Scheme and that involves building a 24-kilometre pipeline from Liverpool to Ashfield. That is going to take the sewage that is secondary treated, or greater, to Ashfield so that that will free up some of the flow in the north Georges River sub main to allow development in that area and increased capacity of that sub main. When Sydney Water talked about this they said that that pipe has the potential for maybe a sewage reuse scheme sometime in the future, or whatever, but I think that before the pipe starts being built we really need to look at who can use that sewage and we need to make sure that that pipe is planned and built with whatever requirements, in terms of pressure or flow or in terms of access to that pipe; that it is built optimally for industries between Liverpool and Ashfield to tap into it and be able to use it. Our aim should be for nothing more than a trickle of that secondary treated water to actually make it to Ashfield” [162].

4.28 Acknowledging these kinds of suggestions, Mr Nemtzow, Director General of the Department of Energy, Utilities and Sustainability told the Committee that whilst he believed that Sydney’s water management bodies were performing effectively, he also believed there was scope for improvement:

“Can we do better? Yes. Would we like to recycle it and to use the stormwater more? Yes. But for reasons we have talked about today and I know your Committee has looked at, there are limitations to that – engineering limitations, pumping water uphill, social and financial limitations. I guess I would just describe it as progress and I think it is in the right direction. I think the pace is pretty good, but there is more to go, a lot more left” [163]

[160] Submission 22, Dr Khan, p14
[161] Dr Khan, Evidence, 20 March 2006, p14
[162] Dr Khan, Evidence, 20 March 2006, p14
[163] Mr Nemtzow, Evidence, 23 March 2006, p22

According to a report in the Sunday Telegraph, the Government’s plan involves recommissioning disused natural gas pipes to help distribute the recycled water. This aspect of the plan was originally developed by Veolia Water and AGL during 2005. As the Sydney Morning Herald reported more than a year ago:

The AGL proposal involves re-using old gas mains, by lining them with plastic and, in some areas, laying new water pipes in the same trenches as new gas pipes.

Several potential customers have already been identified, including Shell, Visy Industries, Sithe Energies, Orica, Caltex and Amcor. Other customers could include golf courses, local councils and even residential customers in new housing.

All good stuff. So who’s proposal do I think is better, Debnam’s or Iemma’s?

On balance, I think they’re very similar. They both propose to use the same water from the same western Sydney treatment plants for very similar applications. Both would (of course!) press on with Sydney Water’s existing projects to further expand the dual-reticulation schemes in Rouse Hill and other new housing development areas, as well as the existing project to increase flows in the Hawkesbury-Nepean River.

Debnam has placed a higher emphasis on treatment quality in some areas so that he can “flick the switch”, as he says, to redirect some of the water to Sydney’s drinking water supplies if needed. Iemma’s emphasis is on distribution networks to deliver a lower-quality water to industry. Neither have proposed to recycle any significant volume from the three largest plants at Bondi, Malabar or North Head (however, both intend to use water from the south western plants which would otherwise end up at Malabar). Debnam has promised $25 million to “investigate further recycling initiatives” for the three large plants (which is such a miniscule and poorly defined component of his $955.7 million announcement that it barely warrants mentioning).

A greater point of difference remains on seawater desalination. Iemma is desperate to build a plant as quickly as possible, while Debnam appears to accept –at least in principle- that a dedicated approach to water recycling may be a viable current alternative for Sydney.

While engineering costs are currently experiencing a high rate of inflation, desalination technology has been significantly reducing in costs over the last few decades. This has been the result of technological improvements, as well as more players entering the market. I believe that if we can postpone the need to desalinate the ocean for as little as a decade, further technological improvements will deliver us a significantly cheaper, more energy-efficient plant, as well as much more environmentally sustainable solutions for managing the brine. A commitment to water conservation and doing more with what we have offers us our best opportunity to avoid purchasing a polluting energy-guzzler in favour of an improved later model. To achieve that, we need to take a serious look at the billion litres of water that we currently discharge into the ocean every day from North Head, Bondi and Malabar.

That’s what I reckon.


Anonymous said...

A whole week without a comment thats a first...

Stuart Khan said...

I figure they're all busy looking for the Mosman Sewage Treatment Plant...

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