Desal plants might do less damage to marine environments than we thought



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Some sea creatures are displaced by the desalination plant, but others actually grow.
Supplied

Graeme Clark, UNSW and Emma Johnston, UNSW

Millions of people all over the world rely on desalinated water. Closer to home, Australia has desalination plants in Melbourne, Adelaide, Perth, the Gold Coast, and many remote and regional locations.

But despite the growing size and number of desalination plants, the environmental impacts are little understood. Our six-year study, published recently in the journal Water Research, looked at the health the marine environment before, during and after the Sydney Desalination Plant was operating.




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Our research tested the effect of pumping and “diffusing” highly concentrated salt water (a byproduct of desalination) back into the ocean.

Contrary to our expectation that high salt levels would impact sea creatures, we found that ecological changes were largely confined to an area within 100m of the discharge point, and reduced shortly after the plant was turned off. We also found the changes were likely a result of strong currents created by the outfall jets, rather than high salinity.

Desalination is growing

We examined six underwater locations at about 25m depth over a six-year period during which the plant was under construction, then operating, and then idle. This let us rigorously monitor impacts to and recovery of marine life from the effects of pumping large volumes of hypersaline water back into the ocean. We tested for impacts and recovery at two distances (30m and 100m) from the outfall.

This study provides the first before-and-after test of ecological impacts of desalination brine on marine communities, and a rare insight into mechanisms behind the potential impacts of a growing form of human disturbance.

About 1% of the world’s population now depends on desalinated water for daily use, supplied by almost 20,000 desalination plants that produce more than 90 million cubic meters of water per day.

Increasingly frequent and severe water shortages are projected to accelerate the growth in desalination around the world. By 2025, more than 2.8 billion people in 48 countries are likely to experience water scarcity, with desalination expected to become an increasingly crucial water source for many coastal populations.

Effect of the diffusers

The diffusers that pump concentrated salt water into the ocean at a high velocity (to increase dilution) are so effective that salinity was almost at background levels within 100m of the outfall. However, the diffusion process increased the speed of currents close to the outfall.

This strong current affects species differently, depending on how they settle and feed. Marine species with strong swimming larvae, such as barnacles, can easily settle in high flow and then benefit from faster delivery of food particles. These animals increased in number and size near the outfall. In contrast, species with slow swimming larvae, such as tubeworms, lace corals and sponges, prefer settling and feeding in low current and became less abundant near the outfall.

Therefore, the high-pressure diffusers designed to reduce hypersalinity may have inadvertently caused impacts due to flow. However, these ecological changes may be less concerning than those caused by hypersalinity, as the currents were still within the range that marine communities experience naturally.

Our findings are important, because as drought conditions around the nation worsen and domestic water supplies are coming under strain, desalination is starting to ramp up in eastern and southern Australia.

For instance, water levels at Sydney’s primary dam at Warragamba have dropped to around 65% and the desalination plant is contracted to start supplying drinking water back into the system when dam levels fall below 60%. This plant can potentially double in capacity if needed.




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There is a rapid expansion of the use of desalination, with global capacity increasing by 57% between 2008 and 2013. Our results will help designers and researchers in this area ensure desalination plants minimise their effect on local coastal systems.The Conversation

Graeme Clark, Senior Research Associate in Ecology, UNSW and Emma Johnston, Professor and Dean of Science, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Giving environmental water to drought-stricken farmers sounds straightforward, but it’s a bad idea


Erin O’Donnell, University of Melbourne and Avril Horne, University of Melbourne

Deputy Prime Minister Michael McCormack last week suggested the government would look at changing the law to allow water to be taken from the environment and given to farmers struggling with the drought.

This is a bad idea for several reasons. First, the environment needs water in dry years as well as wet ones. Second, unilaterally intervening in the way water is distributed between users undermines the water market, which is now worth billions of dollars. And, third, in dry years the environment gets a smaller allocation too, so there simply isn’t enough water to make this worthwhile.




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In fact, the growing political pressure being put on environmental water holders to sell their water to farmers is exactly the kind of interference that bodies such as the Commonwealth Environmental Water Holder were established to avoid.

The environment always needs water

The ongoing sustainable use of rivers is based on key ecosystem functions being maintained, and this means that environmental water is needed in both wet and dry years. The objectives of environmental watering change from providing larger wetland inundation events in wet years, to maintaining critical refuges and basic ecosystem functions in dry years.

Prolonged dry periods cause severe stress to ecosystems, such as during the Millennium Drought when many Murray River red gums were sickened by salinity and lack of water. Environmental water is essential for ecosystem survival during these periods.

Under existing rules, environmental water holders can sell and buy water so as to deliver maximum benefits at the places and times it is most needed.

But during dry years the environmental water holders receive the same water allocations as other users. So it’s very unlikely there will be any “spare” water during drought. During a dry period, the environment is in urgent need of water to protect endangered species and maintain basic ecosystem functions.

We should be cautious when environmental water is sold during drought, as this compromises the ability of environmental water holders to meet their objectives of safeguarding river health. When the funds from the sale are not used to mitigate the loss of the available water to the environment, this is even more risky.

Secure water rights support all water users

In response to McCormack’s suggestion, the National Irrigators’ Council argued that compulsorily acquiring water from the environment can actually hurt farmers who depend on the water market as a source of income or water during drought.

Water markets are underpinned by clear legal rights to water. In other words, the entitlements the environment holds are the same as those held by irrigators. If the government starts treating environmental water rights as barely worth the paper they’re printed on, farmers would have every reason to fear that their own water rights might similarly be stripped away in the future.

Maintaining the integrity of the water market is important for all participants who have chosen to sell water, based on reasonable expectations of how prices will hold up.

Can taking environmental water actually help farmers?

As federal Water Resources Minister David Littleproud noted this week, environmental water is only about 8% of total water allocations in storage throughout the Murray Darling Basin. In the southern basin, it is still only about 14%. This means that between 86% and 92% of water currently sitting in storage is already allocated to human use, including farming.

There are calls for the Commonwealth government to treat the drought as an emergency and to take (or “borrow”) water from environmental water holders. But the Murray-Darling Basin Plan already has specific arrangements in place for emergencies in which critical human water needs are threatened.

The current situation in New South Wales is not an emergency under the plan. Water resources across the northern Murray-Darling Basin are indeed low, but storages in the southern basin are still 50-75% full. Although many licence holders in NSW received zero water in July’s round of allocations, high-security water licences are at 95-100%. In northern Victoria, most high-reliability water shares on the Murray are at 71% allocation.

The situation can therefore be managed using existing tools, such as providing direct financial support to farming communities and buying water on the water market.

Environmental water is an investment, not a luxury

As Australia’s First Nations have known for millennia, a healthy environment is not an optional extra. It underpins the sustainability and security of the water we depend on. When river flows decline, the water becomes too toxic to use.




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Water has been allocated to the environment throughout the Murray-Darling Basin to prevent the catastrophic blue-green algal blooms and salinity problems we have experienced in the past. If we want safe, secure water supplies for people, livestock and crops, we need to keep these key river ecosystems alive and well during the drought.

In the past decade alone, Australia has spent A$13 billion of taxpayers’ money to bring water use in the Murray-Darling Basin back to sustainable levels. If we let our governments treat the environment like a “water bank” to spend when times get tough, this huge investment will have been wasted.The Conversation

Erin O’Donnell, Senior Fellow, Centre for Resources, Energy and Environment Law, University of Melbourne and Avril Horne, Research fellow, Department of Infrastructure Engineering, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Three reasons why it’s a bad idea to ramp up Adelaide’s desalination plant


Sarah Ann Wheeler, University of Adelaide

Drought-affected farmers in New South Wales have called for South Australia to increase the use of its desalination plant to enable an increase in water allocations for other users along the Murray River.

The farmers’ argument is that if Adelaide in particular draws less water from the river more will be available for agriculture in NSW and Victoria.

The logic may sound appealing, but there are three good reasons why it’s not a good idea. Not only is desalination an incredibly expensive project, there are other strategies – like water pricing – that can more effectively reduce water demand.




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It’s also important to remember that the water flowing to South Australia is not “wasted” if it’s not diverted for industry. Stream flows are vital for keeping many ecosystems alive, and there are already serious concerns about current levels.

Adelaide doesn’t use that much water

First, Adelaide uses a very small amount of water from the River Murray. Over the past two decades, average diversions for metropolitan Adelaide and associated country areas have been just over 100 gigalitres (GL). This represents an average 1.25% of the water diversions in the Murray-Darling Basin.

SA in general (including irrigator use) has used an average 11% of water diversions over the past two decades. NSW has diverted 52% of surface water in the Murray-Darling Basin over the same period. Hence, the reality is that ramping up SA’s desal plant will have very little actual impact on NSW irrigators’ water allocations.

South Australia (the grey line) receives much less water from the Murray River than other states.
MDBA Water Audit Monitoring reports, CC BY

Desalination is expensive

Second, increasing desalination has heavy financial and environmental costs. The financial cost is why the plant has been run at only about 10% capacity (the minimum needed to maintain its working condition).

Previous economic analysis by consultants has suggested the desalination plant should only be used to increase water allocations to SA irrigators when temporary water market prices are above A$510 per megalitre (ML).

Given that temporary water prices are now trading around A$300/ML (albeit increasing due to increased water scarcity), we’re still a long way from a financial argument for turning to the desal plant, let alone considering the cost of its negative environmental impacts.




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Water is always variable

Third, we need to take into account the variable nature of Australia’s irrigation sector.

Farmers in NSW are complaining that they are on zero percentages of water allocations at the start of the water year (August 1). This sounds like a big problem. But it doesn’t mean the farmers will get no water from the river at all.

At the start of the season, water managers allot water in districts to irrigators every two weeks. Depending on the type of water entitlement owned, and given the current state of water conditions (e.g. storage, inflows, rainfall predictions), water managers will allocate a percentage of water to high security entitlements first, then general security, then low security. Only in high rainfall years will the low security group get any water. Most years they get none.

Since water was separated from land in the Murray-Darling Basin, this water is not tied to any particular use. Once allocated, irrigators can use their seasonal water for their crops, store it, sell it on the water market, or even choose to let it flow down the river.

It is not unusual for irrigators with low or general security entitlements to start the water year with low or no water allocated, especially in times of water scarcity. One reason is that these rights are traditionally associated with districts where farmers typically grow annual crops like rice and cotton. They have larger farms and more water rights – but also more flexibility about the amount they plant every year.

Low water allocations at the start of the water year act as a signal to these producers to think carefully about the amount of acreage to plant in the coming months. In addition, many NSW and Victorian farmers have access to carry-over water (unused stored water from the previous year).

The other option is the water market; irrigators can enter the water market to buy water. Current temporary water prices are still historically a lot lower than prices in the Millennium Drought, when temporary prices hit over A$1000/ML in many regions.

Finally, it is important to emphasise that water destined for urban use in SA is not “wasted water” for NSW and Victoria. It is still providing surface-water flows in the basin as it makes it way to SA.

Economic studies show that a healthy and sustainable river is worth millions of dollars in tourism and recreation, plus providing important cultural values, on which many small regional town economies are heavily dependent. And there is ongoing evidence that the Murray-Darling Basin is still far from being sustainable.




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Unfortunately, many of the people who support more sustainable water reallocation for the environment are widely dispersed. They often do not have the lobbying power or the resources to engage successfully in policy debate.

The ConversationOf course, farmers need support. But the calls for more water to be allocated to irrigators will sound loudly as the drought continues, and it’s important to remember that there are other, less costly, options that also protect our environment.

Sarah Ann Wheeler, Professor in Water Economics, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Sustainable shopping: tap water is best, but what bottle should you drink it from?



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The greenest option might be to get a disposable bottle but never dispose of it.
Shutterstock.com

Trevor Thornton, Deakin University and Simon Lockrey, RMIT University

Shopping can be confusing at the best of times, and trying to find environmentally friendly options makes it even more difficult. Our Sustainable Shopping series asks experts to provide easy eco-friendly guides to purchases big and small. Send us your suggestions for future articles here.


We have many options when it comes to how we drink water, given the large range of consumer products available, and Australia’s high standards of tap water.

But which option is the smartest choice from an environmental perspective?

According to the waste management hierarchy, the best option is one that avoids waste altogether. Recyclable options are less preferable, and landfill disposal the worst of all.

For water bottles, this suggests that keeping and reusing the same bottle is always best. It’s certainly preferable to single-use bottles, even if these are recyclable.




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Of course, it’s hardly revolutionary to point out that single-use plastic bottles are a bad way to drink water on environmental grounds. Ditching bottled water in favour of tap water is a very straightforward decision.

However, choosing what reusable bottle to drink it out of is a far more complex question. This requires us to consider the whole “life cycle” of the bottle.

Cycle of life

Life-cycle assessment is a method that aims to identify all of the potential environmental impacts of a product, from manufacture, to use, to disposal.

A 2012 Italian life-cycle study confirmed that reusable glass or plastic bottles are usually more eco-friendly than single-use PET plastic bottles.

However, it also found that heavy glass bottles have higher environmental impacts than single-use PET bottles if the distance to refill them was more than 150km.

Granted, you’re unlikely ever to find yourself more than 150km from the nearest drinking tap. But this highlights the importance of considering how a product will be used, as well as what it is made of.

What are the reusable options?

Metal bottles are among the most durable, but also require lots of resources to make.
Flickr CC

In 2011, we investigated and compared the life cycles of typical aluminium, steel and polypropylene plastic reusable bottles.

Steel and aluminium options shared the highest environmental impacts from materials and production, due to material and production intensity, combined with the higher mass of the metal bottles, for the same number of uses among the options. The polypropylene bottle performed the best.

Polypropylene bottles are also arguably better suited to our lifestyles. They are lighter and more flexible than glass or metal, making them easier to take to the gym, the office, or out and about.

The flip side of this, however, is that metal and glass bottles may be more robust and last longer, so their impacts may be diluted with prolonged use – as long as you don’t lose them or replace them too soon.

Health considerations are an important factor for many people too, especially in light of new research about the presence of plastic particles in drinking water.

Other considerations aside, is may even be best to simply buy a single-use PET plastic water bottle and then reuse it a bunch of times. They are lighter than most purpose-designed reusable bottles, but still long-lasting. And when they do come to the end of their useful life, they are more easily recycled than many other types of plastic.

Sure, you won’t look very aspirational, but depending on how many uses you get (as you approach the same number of uses as other options), you could be doing your bit for the environment.

Maintaining reusable options

There are a few things to bear in mind to ensure that reusable bottles produce as little waste as possible.

  1. Refill from the tap, as opposed to using water coolers or other bottled water that can come from many kilometres away, requiring packaging and distribution. Unsurprisingly, tap water has the lowest environmental impacts of all the options.

  2. Clean your bottle thoroughly, to keep it hygienic for longer and avoid having to replace grotty bottles. While cleaning does add to the environmental impact, this effect is minor in comparison to the material impacts of buying new bottles – as we have confirmed in the case of reusable coffee cups.




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The verdict

To reduce your environmental impacts of a drink of water, reusing a bottle, whether a designer bottle or a single-use bottle you use time and again, makes the most sense from a life-cycle, waste and litter perspective.

The maintenance of your reusable container is also key, to make sure you get as many uses as you can out of it, even if you create minor additional environmental impacts to do so.

The ConversationUltimately, drinking directly from a tap or water fountain is an even better shout, if you have that option. Apart from the benefit of staying hydrated, you will reduce your impacts on our planet.

Trevor Thornton, Lecturer, School of Life and Environmental Sciences, Deakin University and Simon Lockrey, Research Fellow, RMIT University

This article was originally published on The Conversation. Read the original article.

Why does some tap water taste weird?



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Which council has Australia’s best-tasting water?
Arthur Chapman/Flickr, CC BY-NC

Ian Wright, Western Sydney University

Every year Australia’s councils contest the academy awards of the water industry: the Best Tasting Tap Water in Australia. Entrants compete on clarity and colour as well as taste and odour.

This week the NSW/ACT representative will be selected to go on to compete against other state winners in October for the coveted Australian crown. (As in Eurovision, the previous winner hosts the final, so it will be held in Toowoomba, which swept the competition last year with its Mt Kynock Water Treatment Plant vintage.)




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It’s a not-so-serious business (apart from bragging rights and a nice trophy, the Australian winner will go to an international competition in the US next year) but it raises an interesting question. All tap water has its own tang, imparted by the source, the plumbing and any treatments. How do you think the water coming out of your tap will go?

What makes water taste good?

The odour of tap water is strongly linked to its taste. No surprises there – the combination of taste and odour is well established.




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One of the most common complaints about tap water taste and odour involves chlorine, which is an essential disinfectant used around the world. Chlorine might have an offensive smell, but it is a major weapon against pathogens spreading in our water supplies. Areas with very old and corroded pipes might add more chlorine to counter the risk of microbial contamination entering the system.

Chlorine is highly volatile and you might particularly notice this smell when you run a hot shower. If you want to enjoy drinking water without the chlorine taste or smell, boil it slowly for several minutes. That will remove much of the chlorine. (And then put it in a container in the refrigerator to get much more appealing ice-cold water.)

The taste test

The competition, run by the Water Industry Operators Association of Australia, uses “blind” testing, so the judges do not know the source. All samples need to be at room temperature. The testers use a testing wheel to rate attributes including sweet, sour, salty and bitter.


Water Industry Operators Association

The water will also be judged on clarity, colour, odour and “mouthfeel”. Perhaps the most obvious mouthfeel character of water is effervescence or “sparkling bubbles”, something that consumers will pay plenty for in bottles sourced from exotic-sounding locations.

Hard vs soft

These qualities often reflect water’s origins, which affects aspects like its mineral content. Groundwater generally has a higher mineral content, particularly from areas of limestone rich in calcium and magnesium carbonates. This is called “hard” water.




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Water with high levels of hardness may be frustrating when you wash your hands as it can stop a soapy lather forming. Very hard water might also have a salty taste. Hard water can create other issues, such as imparting an unusual flavour in tea and causing a build-up of scale minerals in hot water appliances and water pipes.

The opposite of hard water is “soft” water. This is often from water supplies fed by stored rainfall, which generally contains very dilute sodium chloride (also known as table salt; it’s largely responsible for making seawater salty).

If you live close to the coast and have a tank collecting runoff from your roof you will probably have more salt in your water. You might not actually taste the salt, but you may notice a metallic tang from corrosion of the roof, tank and plumbing triggered by the salt.

Water supplied by rainwater tanks can provide odd tastes and odours. This can be the first sign of a major problem, and you should always investigate the source. Dead animals in the tanks and accumulated vegetation from overhanging trees can be unwelcome tank water quality hazards. It is worth remembering that homes using rainwater tanks often do not treat or disinfect the water before consumption.




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A sulphur taste and odour can also occur in some water supplies. This is often termed “rotten-egg gas”, and is caused by hydrogen sulphide. Similar to chlorine, its odour might be detected when running a hot shower. The source of sulphur can be from the water supply geology or from the decay of organic matter.

More and more of Australia’s water supply is highly treated by the local or regional water industry. We have increasing populations and a possibly drying climate. Some areas have a relatively natural supply of high-quality raw water from very clean catchments and storages. Melbourne, Brisbane and Sydney and many locations across Tasmania are fortunate to have very clean and mostly natural water supplies. Other places, like Alice Springs or Perth, rely heavily on treated groundwater.

Desalination has also emerged as a major new water supply source over the last 20 years. It is often used only when lack of rainfall depletes natural water storage, but it is a permanent factor in Perth’s water supply.

It will be a major victory for the Australian water industry if the winning water sample comes from a recycled water supply, particularly if the source includes some component of recycled sewage!


The Conversation


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Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University

This article was originally published on The Conversation. Read the original article.

More of us are drinking recycled sewage water than most people realise



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The Hawkesbury’s waters look beautifully natural but treated sewage makes up to 20% of the river flow where the North Richmond Filtration Plant draws its water.
Karl Baron/flickr, CC BY

Ian Wright, Western Sydney University

The world is watching as Cape Town’s water crisis approaches “Day Zero”. Questions are being asked about which other cities could be at risk and what can they do to avoid running dry. In Perth, Australia’s most water-stressed capital, it has been announced that the city is considering reusing all of its sewage as part of its future water supply.




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Drinking recycled sewage is a very confronting topic. But what many people don’t realise is that we already rely on recycled sewage in many Australian water supplies. Even in Australia’s biggest city, Sydney, it is an important part of the water supply. This is because many large towns discharge their treated sewage into the catchment rivers that supply the city.

But Perth is now looking to recycle all of its treated sewage. At the time of writing, the city’s water storages were at a low 35.3%. Cape Town’s reserves, by comparison, are at a critical low of 23.5% – but Perth was close to that point just a year ago when it was down to 24.8%.

Perth has been progressively “drought-proofing” itself by diversifying the city water supply. River flow and storage in dams accounts for only 10% of this supply. Desalination and groundwater extraction provide about 90% of the city’s supply. Only about 10% of Perth’s sewage is recycled, through advanced treatment and replenishment into its groundwater supplies.




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Justifiably, many people have concerns about drinking recycled sewage. This reflects long-standing concern about hazards of contaminated water. An example is the devastating waterborne disease of cholera, which claims the lives of more than 100,000 people a year. Cholera is rare in many countries, but is endemic in waters across Africa and much of Southeast Asia.

As wastewater treatment technologies improve and urban populations grow, however, interest in using treated sewage in drinking water supplies has been increasing. No Australian urban water supply currently uses “direct potable reuse” of treated sewage, but the concept is being seriously considered.




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So how is treated sewage being indirectly reused?

There is, however, indirect reuse when water is drawn from rivers into which recycled sewage is discharged upstream. For instance, the catchment of Sydney’s giant Warragamba Dam has a population of about 116,000 people. This includes the large settlements of Goulburn, Lithgow, Moss Vale, Mittagong and Bowral. These communities discharge their treated sewage into the catchment rivers.

Several large towns discharge treated sewage into rivers supplying Warragamba Dam, which holds 80% of Sydney’s water reserves.
popejon2/flickr, CC BY-NC-ND

The New South Wales Environment Protection Authority regulates these discharges, which form a small part of the total annual catchment inflow to the dam. Such recycling of sewage is termed “indirect potable reuse”.

Residents in some parts of northwestern Sydney also drink water that is partly supplied by another form of indirect reuse of treated sewage. The North Richmond Water Filtration Plant extracts and treats water drawn directly from the Hawkesbury-Nepean River. A major contributor to the river flow is treated sewage discharged from upstream treatment plants.

These include plants in the Blue Mountains (Winmalee), St Marys, Penrith, Wallacia, and West Camden. The largest individual discharge of treated sewage to the river in recent weeks is from St Marys Advanced Water Recycling Plant, one of the biggest in Australia. This plant uses advanced membrane technology to produce highly treated effluent before it is discharged into the river.

St
Marys Advanced Water Recycling Plant, one of the biggest in Australia, treats sewage and discharges the water into the Hawkesbury-Nepean River.

Ian Wright, Author provided

Available data are limited, but in the very low river flows in the recent dry summer I estimate that treated sewage comprised almost 32% of the Hawkesbury-Nepean flow in the North Richmond area for the first week of January. The water is highly treated at the Sydney Water-owned North Richmond plant to ensure it meets Australian drinking water guidelines.

Every year the river receives more and more treated sewage as a result of population growth. This is certain to continue, as Greater Sydney is forecast to gain another 1.74 million residents in the next 18 years. Much of this growth will be in Western Sydney, one of the most rapidly growing urban centres in Australia. This will result in more treated sewage, and urban runoff, contributing to the Hawkesbury-Nepean River flow.




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Paying for desalination while water goes to waste

However, most of Sydney’s sewage is not recycled at all. Three massive coastal treatment plants (at North Head, Bondi and Malabar) serve the majority of Sydney’s population. These three plants discharge nearly 1,000 million litres (1,000ML) of primary treated sewage into the ocean every day. That is roughly an Olympic pool of sewage dumped in the ocean every four minutes!

Perhaps if Sydney was as chronically short of water as Perth there would be plans to recycle more of its sewage. Instead, Sydney has adopted desalination as a “new” source of drinking water, rather than treating larger volumes of sewage for any form of potable reuse.

Sydney’s desalination plant sits idle about 10 kilometres south of the Malabar treatment plant. It has a capacity for supplying 250ML a day. Even though it isn’t supplying water now, it is very expensive. In 2017, the privately owned plant, sitting on standby, charged Sydney Water A$194 million.

Only when Sydney’s storages fall below the trigger of 60% will the plant supply drinking water. With storages at 76.5%, the plant will not operate for a while.


The Conversation


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Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University

This article was originally published on The Conversation. Read the original article.