How to get people to eat bugs and drink sewage



Disgust may be an impediment to many of us adopting more sustainable lifestyles, from considering alternative foods to drinking recycled water
http://www.shutterstock.com

Nathan S Consedine, University of Auckland

In wealthy societies we’ve become increasingly picky about what we eat. The “wrong” fruits and vegetables, the “wrong” animal parts, and the “wrong” animals inspire varying degrees of “yuck”.

Our repugnance at fruit and vegetables that fail to meet unblemished ideals means up to half of all produce is thrown away. Our distaste at anything other than certain choice cuts from certain animals means the same thing with cows and other livestock slaughtered for food. As for eating things like insects – perfectly good in some cultures – forget about it.

Disgust has its advantages. Its origins likely lie in the basic survival benefit of avoiding anything that smells or tastes bad. But disgust may also be an impediment to many of us adopting more sustainable lifestyles – from eating alternative sources of protein to drinking recycled water.




Read more:
Eating insects: good for you, good for the environment


Can anything be done about this? The fact that disgust varies between cultures and across ages implies it can. But how?

We set out to answer this by getting a better grip on how disgust works, focusing on disgust in everyday food choices, rather than aversions to the unknown or unfamiliar.

Our research suggests some disgust responses, once set early in childhood, are hard to shift.
But responses involving culturally conditioned ideas of what is “natural” may be modified over time.

Don’t eat that!

Disgust likely began as a powerful “basic” emotional reaction that evolved to steer us away from (and literally eject) potential contaminants – food that smelled and tasted bad. You can think of it as originally being a “don’t eat that” emotion.

The disgust system tends to be “conservative” – rejecting valid sources of possible nutrition that have characteristics implying they might be risky, and guiding us towards food choices that are ostensibly safer. Research by University of British Columbia psychologist Mark Schaller and colleagues suggests people who live in areas with historically high rates of disease not only have stricter food preparation rules but more “conservative” cultural traditions generally.

Is is unclear exactly how or when individual templates for what is disgusting are set, but generally what is seen as “disgusting” is set relatively early in life. Culture, learning and development all help shape disgust.

It’s just not natural!

In our study, we showed 510 adults pairs of “normal” and “alternative” products via an online survey, and asked them how much they would be willing to pay for the alternatives. We also asked them to rate which product was tastier, healthier, more natural, visually appealing and nutritious. Product pairs included:

  • shiny and typically shaped fruits and vegetables vs knobbly, blotchy, gnarled and multi-limbed examples.
  • plant protein foods vs insect-based foods
  • standard drinks vs drinks with ingredients reclaimed from sewage
  • standard medicines vs medicines with ingredients extracted from sewage.
Out of shape: using common fruits and vegetables meant the study’s results were not muddied by responses affected by fear of the unknown.
http://www.shutterstock.com

Our results show that, even after statistically adjusting for obvious factors like pro-environmental attitudes, those with a greater “disgust propensity” are less willing to consume atypical (weird-looking) products.

This may seem rather obvious but most prior studies have muddled a food’s “novelty” with its possible disgusting properties (by asking people, for example, whether they’d eat bugs). By asking about really common fruits and vegetables, our study shows just how far disgust may reach in influencing what we consume.




Read more:
Neigh-sayers: why we won’t agree to eat a dead horse


As importantly, our results suggest evaluations of a product’s perceived naturalness, taste, health risk, and visual appeal “explains” about half of the disgust effect.

In particular, lack of perceived “naturalness” was a frequently reason for unwillingness to pay for product alternatives. This result was in line with previous studies that have looked attitudes to eating insects or lab-grown meat. This is a promising area for social marketing.

Therapeutic responses

Given evidence about how much of what we consider disgusting is cultural and learned, marketing campaigns could help shift attitudes about what is “natural”. It has been done before. Consider this advertisement to naturalise sugar consumption.

Thinking differently about emotion-eliciting stimuli is termed “reappraisal”. Reappraisal has been shown to reduce disgust effects among those with obsessive compulsive disorder. Desensitisation (repeated exposures) seems less effective in reducing disgust (versus fear) among people with diagnosed phobias, but it may work better among the general population.




Read more:
From disgust to deceit – a shorter path than you might think


Of course, such speculations remain untested and their ultimate success remains unclear.

But it wasn’t so long ago that Western consumers turned their noses up at fermented foods, and the notion of “friendly bacteria” made as much sense as “friendly fire”. More than a decade ago the residents of a drought-stricken Australian town voted against recycling sewage for drinking water. Now the residents of an Australian city accept recycled sewage being pumped back into the city’s groundwater.

Given time, circumstance and a little nudging, a future meal at your favourite Thai restaurant may well involve ordering a plate of insects.The Conversation

Nathan S Consedine, Professor of Health Psychology, University of Auckland

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

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Paddling blind: why we urgently need a water audit



There’s broad support from communities and farmers for proper water audits.
John/Flickr, CC BY-SA

Quentin Grafton, Crawford School of Public Policy, Australian National University and John Williams, Australian National University

In the wake of a damning royal commission and an ABC Four Corners investigation, the federal government has created an Inspector General for the Murray-Darling Basin, to combat water theft, ensure water recovery and efficiency projects are delivered properly, and essentially make sure everyone is acting as they should.

While this is a laudable aim, the Inspector General – currently former Australian Federal Police Commissioner Mike Keelty – cannot hope to do this job without knowing how much water is being used in the Basin, by whom it is used, and where.




Read more:
Billions spent on Murray-Darling water infrastructure: here’s the result


This might seem like basic information, but the Bureau of Meteorology, the Murray-Darling Basin Authority and state water accounts are not up to the task.

We urgently need a comprehensive audit to track the water in the Murray Darling Basin, so Inspector General Keelty can effectively investigate what he has already described as a “river ripe for corruption”.

Up the creek

Back in 2004 all governments in Australia agreed to track and provide information on water in terms of planning, monitoring, trading, environmental management, and on-farm management.

But water accounts still lack many essential features including double-entry accounting. When applied to water, double-entry accounts means that when one person consumes more water, someone else must consume less.




Read more:
Aboriginal voices are missing from the Murray-Darling Basin crisis


The technology to track this already exists: satellites that can quantify surface water are successfully being used used in the United States.

If we had monthly water consumption measurements, we could see how much water is being used, by whom, when and where. This would help decision makers see problems before they emerge, such as the mass fish deaths in the Darling River, and respond in real time.

As a recent report from the Natural Resources Commission shows, without proper accounting, too much water is taken upstream – seriously harming downstream communities.

Wide support for an audit

An independent Basin-wide water audit is supported by communities and some irrigators.

In July NSW farmers voted in support of a federal royal commission into “the failings of the Murray Darling Basin Plan”. In our view, this vote shows many farmers support much greater transparency about how much water is being consumed, and by whom.




Read more:
The Darling River is simply not supposed to dry out, even in drought


Double-entry water consumption accounts would help identify whether the billions of dollars planned in subsidies to increase irrigation efficiency will actually deliver value for money. But irrigation improvements only generate public benefits when more water is left or returns to flow in streams and rivers. Such flows are essential to healthy rivers and sustainable Basin communities.

Irrigators’ crops benefit from increased efficiency, so subsidies help farmers greatly – but it is very unclear whether they do anything for the public good. In fact, they seem to reduce the amount of water that finds its way back into the rivers. Research also shows infrastructure subsidies to improve irrigation efficiency typically increases water consumption at the Basin level.

Our research, published earlier this year in the Australasian Journal of Water Resources shows federal irrigation infrastructure subsidies may have reduced net stream and river levels. This is even after accounting for the water entitlements irrigators provided to the government in exchange for these subsidies.




Read more:
5 ways the government can clean up the Murray-Darling Basin Plan


Independent audits

Just like financial accounts, water accounts must be independently audited.

For the average taxpayer, who has to justify every dollar they get from the government, it’s hard to imagine how some corporations can be given millions of dollars in subsidies without actual measurements (before and after) of the claimed water savings.

If Newstart recipients need to report and manage their income and have a job plan, as part of a system of appropriate checks and balances, shouldn’t the Australian government also be checking whether billions spent on subsidies for irrigators actually saves water?




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The Murray-Darling Basin scandal: economists have seen it coming for decades


A water audit would cost less than 1% of the money already spent on water infrastructure subsidies in the Basin. Unlike irrigation infrastructure subsidies, a water audit is value for money.

Importantly, independent water consumption accounts would allow the Inspector General for the Murray-Darling Basin to effectively manage our most critical nature resource, water.The Conversation

Quentin Grafton, Director of the Centre for Water Economics, Environment and Policy, Crawford School of Public Policy, Australian National University and John Williams, Adjunct Professor Environment and Natural Resources, Crawford School of Public Policy, Australian National University

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

2℃ of global warming would put pressure on Melbourne’s water supply



Sunburnt Victorian fields are set to become more common under climate change.
Fir0002/Flagstaffotos/Wikimedia Commons, CC BY-NC-SA

Ben Henley, University of Melbourne; Andrew King, University of Melbourne; Anna Ukkola, Australian National University; Murray Peel, University of Melbourne, and Rory Nathan, University of Melbourne

Melbourne’s existing water supplies may face pressure if global warming hits the 2℃ level, according to our new research published today in Environmental Research Letters.

The effects of drying and warming in southern Australia are expected to reduce natural water supplies. If we overshoot 2℃ of warming, even the desalination plant might not provide enough drinking water to a growing population.

However, keeping warming to 1.5℃ would help avoid many of these negative consequences. This brings home the local benefits of acting swiftly to limit global warming. Luckily, there are options available to secure our water supply.

Warming and drying effects

The Earth has warmed by about 1.1℃ since pre-industrial times, causing ongoing global changes to our atmospheric composition. The Paris Agreement commits the world to holding the increase to “well below” 2℃, and “pursuing efforts” to limit the increase to 1.5℃.

While we’re confident there will be more hot extremes and fewer cold extremes as global temperatures rise, the consequences of further global warming for other climate extremes – such as drought – in different parts of the world are harder to pinpoint.




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Our study uses climate models to identify the possible changes in average rainfall and temperature in four different worlds:

  • the “Natural” world, where humans have had no influence on the climate,

  • the “Current” world, which approximates the impacts humans have had to date, and

  • two future worlds, which are “1.5℃” and “2.0℃” warmer than pre-industrial times.

In line with previously published results, southern Australia is projected to undergo drying and warming. But we are not alone. The Mediterranean and Southwestern North America are also predicted to dry out.

Desalination is increasingly important

Most Australians recall the severity and length of the Millennium Drought. This event severely stressed agricultural and natural systems, and led to the commissioning of desalination plants in the five largest cities in Australia, at a cost of several billion dollars.

Desalination offers an important lifeline. Although it comes with high short-term costs, it supplies vital water security over the long term. Successful efforts to improve water-use efficiency have reduced per capita demand rates, but growing populations in major centres will lead to increasing water demand.

Rainfall deficiencies over Australia for the 18 months between 1 Feb 2018 and 31 July 2019.
Bureau of Meteorology

Right now, large parts of southeastern Australia are in the grips of another drought. Although drought is a common natural feature of Australia’s climate, in recent decades we have observed long-term drying trends over much of southern Australia.

Currently, all capital city urban reservoir systems in southern Australia are below 60%, and several are nearing or below 50%. The Victorian government recently ordered 125 gigalitres of water from the desalination plant.

Urban water storage levels for Australia’s capital cities.
Bureau of Meteorology

With these challenges in mind, our paper explores the effects of future climate change on the surface water supply infrastructure for Melbourne.

Climate models and hydrological models together indicate future declines in catchment inflows as global warming increases from 1.5℃ to 2℃. The good news is when desalination is added to the mix, which it is, pressure on our water storage is dramatically reduced. However, population growth and climate change remain key challenges into the future.

The buffer is shrinking

The take-home message is, if global warming approaches 2℃ and beyond, the combined impacts of climate change and population growth will ultimately begin to outstrip the buffer desalination provides for us without ongoing investment in water security. Fortunately, desalination plants, storm water, water recycling and continuing to improve efficiency are all viable options.

To ensure our water security, and with it, the safety and prosperity of the urban centres which are the engine houses of the Australian economy, we all need to be vigilant in managing water resources.

We also all need to play an active part in the global effort to reduce the impacts of climate change. The commitments by the world’s nations for the 2020-30 period remain insufficient to achieve the temperature goals. Global emission rates continue to rise, and atmospheric greenhouse gas concentrations are steadily accelerating.

The task of turning around our emissions in time to avert many of the serious impacts of climate change is becoming ever more implausible. In the coming 10–20 years, we expect to shoot past 1.5℃.




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With so much momentum in both human and natural systems it is becoming increasingly unlikely that we will avoid warming beyond 1.5℃. However, if we can achieve it, the list of benefits includes greatly reduced stress on the water supplies we rely on for our very existence.The Conversation

Ben Henley, Research Fellow in Climate and Water Resources, University of Melbourne; Andrew King, ARC DECRA fellow, University of Melbourne; Anna Ukkola, Research Associate, Climate Change Research Centre, Australian National University; Murray Peel, Senior lecturer, University of Melbourne, and Rory Nathan, Associate Professor Hydrology and Water Resources, University of Melbourne

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

There’s a simple way to drought-proof a town – build more water storage



Inland towns need far more water storage.
Flickr/Mertie, CC BY-SA

Michael Roderick, Australian National University

The federal parliament has voted to funnel A$200 million to drought-stricken areas. What exactly this money will be spent on is still under consideration, but the majority will go to rural, inland communities.

But once there, what can the money usefully be spent on? Especially if there’s been a permanent decline in rainfall, as seen in Perth. How can we help inland communities?




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Let’s look at the small inland town of Guyra, NSW, which is close to running dry. Unlike our coastal cities, Guyra cannot simply build a billion-dollar desalination plant to supply its water. Towns like Guyra must look elsewhere for its solutions.

Running dry isn’t just about rainfall

“Running dry” means there is no water when the tap is turned on. It seems to make sense to blame the drought for Guyra’s lack of water. But the available water supply is not only determined by rainfall. It also depends on amount of water flowing into water storage (called streamflow), and the capacity and security of that storage.

While Perth has had a distinct downturn in its rainfall since the 1970s and has built desalination plants to respond to this challenge, no such downturn is evident at Guyra. Indeed, to date, the driest consecutive two years on record for Guyra were 100 years ago (1918 and 1919).

Long-term rainfall records for Perth (left) and Guyra (right). Dashed red line shows the trend and the full yellow line shows 600 mm annual rainfall.
Bureau of Meteorology

Despite the differences, there are some similarities between Perth and Guyra. As a rule of thumb, in Australia, significant streamflow into water storages does not occur until annual rainfall reaches around 600mm. This occurs as streamflow is generally supplied from “wet patches” when water can no longer soak into the soil. Thus, if annual rainfall is around 600mm or below, we generally anticipate very little streamflow.

While Guyra has seen some rain in 2019, it is not enough to prompt this crucial flow of water into the local water storage. The same is true for Perth, with annual rainfall in the past few decades now hovering close to the 600mm threshold.

Importantly, rainfall and streamflow do not have a linear relationship. Annual rainfall in Perth has declined by around 20%, but Perth’s streamflow has fallen by more than 90%.

With little streamflow filling its dams, Perth had little choice but to find other ways of increasing its water supply. They built desalination plants to make up the difference.

Let’s return to Guyra in NSW and the current drought. The rainfall records do not indicate there is a long-term downward trend in rainfall. But even without a rainfall trend, there are still dry years when there is little streamflow. Indeed, in Guyra, the rainfall record shows that, on average, the rainfall will be 600mm or less roughly one year out of every ten years.

Build more storage

So how do the residents of Guyra ensure a reliable water supply, given that they cannot build themselves a desalination plant?

Well, in this case, you can simply get water from somewhere else if it is available. A pipeline is currently under construction to supply Guyra from the nearby Malpas Dam, and is expected to be in operation very soon.

But that’s not always an option. A made-in-Guyra water solution means one thing: expanding storage capacity.

Guyra can generally store around 8 months of their normal water demand (although of course demand varies with the seasons, droughts, water restrictions and price per litre).

To give a point of comparison, Sydney can store up to five years of its normal water demand, and has a desalination plant besides. Despite these advantages, Sydney residents are now under stage one water restrictions which happens when its storages are only 50% full. Yet, even when Sydney’s glass is only half-full, that city still has at least another two years of water left to meet the expected water demand even without using desalination.

By comparison, when water storages in Guyra are 50% full, they have less than six months normal water supply.

It is astonishingly difficult to find accurate data on small-town water supplies but in my experience Guyra is not unique among rural towns. There is a big divide between the water security of those living in Australia’s big cities compared to smaller inland towns. Many rural communities simply do not have sufficient water storage to withstand multi-year droughts, and in some cases, cannot even withstand one year of drought.




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Droughts, extreme weather and empowered consumers mean tough choices for farmers


Nature, drought and climate change cannot be blamed for all of our water problems. In rural inland towns, inadequate planning and funding for household water can sometimes be the real culprit. Whether Australians live in rural communities or big cities, they should be treated fairly in terms of both the availability and the quality of the water they use.The Conversation

Michael Roderick, Professor, Research School of Earth Sciences and Chief Investigator in the ARC Centre of Excellence for Climate Extremes, Australian National University

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

Expanding gas mining threatens our climate, water and health


Melissa Haswell, Queensland University of Technology and David Shearman, University of Adelaide

Australia, like its competitors Qatar, Canada and the United States, aspires to become the world’s largest exporter of gas, arguing this helps importing nations reduce their greenhouse emissions by replacing coal.

Yes, burning gas emits less carbon dioxide than burning coal. Yet the “fugitive emissions” – the methane that escapes, often unmeasured, during production, distribution and combustion of gas – is a much more potent short-term greenhouse gas than carbon dioxide.




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A special report issued by the World Health Organisation after the 2018 Katowice climate summit urged governments to take “specific commitments to reduce emissions of short-lived climate pollutants” such as methane, so as to boost the chances of staying with the Paris Agreement’s ambitious 1.5℃ global warming limit.

Current gas expansion plans in Western Australia, the Northern Territory and Queensland, where another 2,500 coal seam gas wells have been approved, reveal little impetus to deliver on this. Harvesting all of WA’s gas reserves would emit about 4.4 times more carbon dioxide equivalent than Australia’s total domestic energy-related emissions budget.

Gas as a cause of local ill-health

There are not only global, but also significant local and regional risks to health and well-being associated with unconventional gas mining. Our comprehensive review examines the current state of the evidence.

Since our previous reviews (see here, here and here), more than 1,400 further peer-reviewed articles have been published, helping to clarify how expanding unconventional gas production across Australia risks our health, well-being, climate, water and food security.




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This research has been possible because, since 2010, 17.6 million US citizens’ homes have been within a mile (1.6km) of gas wells and fracking operations. Furthermore, some US research funding is independent of the gas industry, whereas much of Australia’s comparatively small budget for research in this area is channelled through an industry-funded CSIRO research hub.

Key medical findings

There is evidence that living close to unconventional gas mining activities is linked to a wide range of health conditions, including psychological and social problems.

The US literature now consistently reports higher frequencies of low birth weight, extreme premature births, higher-risk pregnancies and some birth defects, in pregnancies spent closer to unconventional gas mining activities, compared with pregnancies further away. No parallel studies have so far been published in Australia.

US studies have found increased indicators of cardiovascular disease, higher rates of sinus disorders, fatigue and migraines, and hospitalisations for asthma, heart, neurological, kidney and urinary tract conditions, and childhood blood cancer near shale gas operations.

Exploratory studies in Queensland found higher rates of hospitalisation for circulatory, immune system and respiratory disorders in children and adults in the Darling Downs region where coal seam gas mining is concentrated.

Water exposure

Chemicals found in gas mining wastewater include volatile organic compounds such as benzene, phenols and polyaromatic hydrocarbons, as well as heavy metals, radioactive materials, and endocrine-disrupting substances – compounds that can affect the body’s hormones.

This wastewater can find its way into aquifers and surface water through spillage, injection procedures, and leakage from wastewater ponds.

The environmental safety of treated wastewater and the vast quantities of crystalline salt produced is unclear, raising questions about cumulative long-term impacts on soil productivity and drinking water security.

Concern about the unconventional gas industry’s use of large quantities of water has increased since 2013. Particularly relevant to Australian agriculture and remote communities is research showing an unexpected but consistent increase in the “water footprint” of gas wells across all six major shale oil and gas mining regions of the US from 2011 to 2016. Maximum increases in water use per well (7.7-fold higher, Permian deposits, New Mexico and Texas) and wastewater production per well (14-fold, Eagle Ford deposits, Texas) occurred where water stress is very high. The drop in water efficiency was tied to a drop in gas prices.

Air exposure

Research on the potentially harmful substances emitted into the atmosphere during water removal, gas production and processing, wastewater handling and transport has expanded. These substances include fine particulate pollutants, ground-level ozone, volatile organic compounds, polycyclic aromatic hydrocarbons, hydrogen sulfide, formaldehyde, diesel exhaust and endocrine-disrupting chemicals.

Measuring concentrations and human exposures to these pollutants is complicated, as they vary widely and unpredictably in both time and location. This makes it difficult to prove a definitive causal link to human health impacts, despite the mounting circumstantial evidence.




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Our review found substantially more evidence of what we suspected in 2013: that gas mining poses significant threats to the global climate, to food and water supplies, and to health and well-being.

On this basis, Doctors for the Environment Australia (DEA) has reinforced its position that no new gas developments should occur in Australia, and that governments should increase monitoring, regulation and management of existing wells and gas production and transport infrastructure.The Conversation

Melissa Haswell, Professor of Health, Safety and Environment, School of Public Health and Social Work, Queensland University of Technology, Queensland University of Technology and David Shearman, Emeritus Professor of Medicine, University of Adelaide

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

When water is scarce, we can’t afford to neglect the alternatives to desalination


Ian Wright, Western Sydney University and Jason Reynolds, Western Sydney University

This is the second of two articles looking at the increasing reliance of Australian cities on desalination plants to supply drinking water, with less emphasis on the alternatives of water recycling and demand management. So what is the best way forward to achieve urban water security?


An important lesson from the Millennium Drought in Australia was the power of individuals to curb their own water use. This was achieved through public education campaigns and water restrictions. It was a popular topic in the media and in daily conversations before the focus turned to desalination for water security.

Water authorities were also expanding the use of treated wastewater – often a polite term for sewage – for “non-potable” uses. These included flushing toilets, watering gardens, and washing cars and laundry.

Today, the emphasis on recycling wastewater in some locations is declining. The arguments for increased water recycling appear to be falling away now that desalinated water is available.




Read more:
Cities turn to desalination for water security, but at what cost?


This trend ignores the fact that the potential supply of recycled water increases as populations grow.

Today most Australian wastewater is treated then disposed into local streams, rivers, estuaries and the ocean. In Sydney, for example, the city’s big three outfalls dump nearly 1 billion litres (1,000 megalitres, ML) a day into the ocean.

Where has recycling succeeded?

Australia has several highly successful water recycling projects.

Sydney introduced the Rouse Hill recycled water scheme in 2001. Highly treated wastewater is piped into 32,000 suburban properties in distinct purple pipes. Each property also has the normal “potable” drinking water supply.

Rouse Hill is considered a world-leading urban recycling scheme. South Australia (Mawsons Lakes) and Victoria (Yarra Valley Water, South East Water) have similar projects.

Our farmers often struggle to secure water for irrigation. Chronic water shortages across the Murray-Darling river system vividly demonstrate this.




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Recycled water can play an important role in agricultural schemes. There are successful examples in South Australia (Virginia Irrigation Scheme), Victoria (Werribee) and New South Wales (Picton).




Read more:
It takes a lot of water to feed us, but recycled water could help


Perth has gone further by embracing water recycling for urban use with plans to treat it to a drinking water standard. Part of the extensive treatment process involves reverse osmosis, which is also used in desalination. The treated water is then pumped into groundwater aquifersand stored.

This “groundwater replenishment” adds to the groundwater that contributes about half of the city’s water supply. The Water Corporation of Perth has a long-term aim to recycle 30% of its wastewater.

Southeast Queensland, too, has developed an extensive recycled water system. The Western Corridor Recycled Water Scheme also uses reverse osmosis and can supplement drinking water supplies during droughts.




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


Demand management works too

Past campaigns to get people to reduce water use achieved significant results.

In Sydney, water use fell steeply under water restrictions (2003-2009). Since the restrictions have ended, consumption has increased under the softer “water wise rules”. Regional centres including (Tamworth) outside of Sydney are under significant water restrictions currently with limited relief in sight.

Despite a 25% increase in Sydney’s population, total demand for drinking water remains lower than before mandatory restrictions were introduced in late 2003.
© Sydney Water, used with permission

The Victorian government appears to be the Australian leader in encouraging urban water conservation. Across Melbourne water use per person averaged 161 litres a day over 2016-18. Victoria’s “Target 155” program, first launched in late 2008 and revived in 2016, aims for average use of 155 litres a day.

In a comparison of mainland capitals Melbourne used the least water per residential property, 25% less than the average. Southeast Queensland residents had the second-lowest use, followed by Adelaide. Sydney, Perth and Darwin had the highest use.

Although Melbourne water prices are among the highest of the major cities, lower annual water use meant the city’s households had the lowest water bills in 2016-17, analysis by the Australian Bureau of Meteorology found.


Calculated from Bureau of Meteorology data, Author provided

What impact do water prices have?

Clearly, water pricing can be an effective tool to get people to reduce demand. This could partly explain why water use is lower in some cities.

Water bills have several components. Domestic customers pay a service fee to be connected. They then pay for the volume of water they use, plus wastewater charges on top of that. Depending on where you live, you might be charged a flat rate, or a rate that increases as you use more water.

The chart below shows the pricing range in our major cities.


https://datawrapper.dwcdn.net/xIJQR/3/


Flat charges for water per kilolitre (where a kL equals 1,000 litres) apply in Sydney ($2.08/kL)), Darwin ($1.95/kL) and Hobart ($1.06/kL.

However, most water authorities charge low water users a cheaper rate, and increased prices apply for higher consumption. The most expensive water in Australia is for Canberra residents – $4.88 for each kL customers use over 50kL per quarter. The cheapest water is Hobart ($1.06/kL).

Higher fees for higher residential consumption are charged in Canberra, Perth, Southeast Queensland, across South Australia and in Melbourne. In effect, most major water providers penalise high-water-using customers. This creates an incentive to use less.

For example, Yarra Valley Water customers in Melbourne using less than 440 litres a day pay $2.64/kL. From 441-880L/day they are charged $3.11/kL. For more than 881L/day they pay $4.62/kL – 75% more than the lowest rate.

Is recycled water getting priced out of business?

Recycling water may not be viable for Sydney Water. It can cost over $5 per 1kL to produce, but the state pricing regulator, IPART, sets the cost of recycled water to Sydney customers at just under $2 per kL. That’s probably well below the cost of production.

Recycled water, where available, is a little bit more expensive ($2.12/kL) in South Australia.

Subsidies are probably essential for future large recycling schemes. This was the case for a 2017 plan to expand the Virginia Irrigation Scheme. South Australia sought 30% of the capital funding from the Commonwealth.

Where to from here?

Much of southern Australia is facing increasing water stress and capital city water supplies are falling. Expensive desalination plants are gearing up to supply more water. Will they insulate urban residents from the disruption many others are feeling in drought-affected inland and regional locations? Should we be increasing the capacity of our desalination plants?

We recommend that urban Australia should make further use of recycled water. This will also reduce the environmental impact of disposing wastewater in our rivers, estuaries and ocean. All new developments should have recycled water made available, saving our precious potable water for human consumption.

Water conservation should be given the highest priority. Pricing of water that encourages recycling and water conservation should be a national priority.




Read more:
This is what Australia’s growing cities need to do to avoid running dry


You can read the first article, on cities’ increasing reliance on desalination, here.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University and Jason Reynolds, Research Lecturer in Geochemistry, Western Sydney University

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

Cities turn to desalination for water security, but at what cost?



File 20190207 174873 kcdlxk.jpg?ixlib=rb 1.1
The largest desalination plant in Australia, Victoria’s A$3.5 billion ‘water factory’ can supply nearly a third of Melbourne’s needs.
Nils Versemann/Shutterstock

Ian Wright, Western Sydney University and Jason Reynolds, Western Sydney University

This is the first of two articles looking at the increasing reliance of Australian cities on desalination to supply drinking water, with less emphasis on alternatives such as recycling and demand management. So what is the best way forward to achieve urban water security?


Removing salts and other impurities from water is really difficult. For thousands of years people, including Aristotle, tried to make fresh water from sea water. In the 21st century, advances in desalination technology mean water authorities in Australia and worldwide can supply bountiful fresh water at the flick of a switch.

Achieving water security using desalination is now a priority for the majority of Australia’s capital cities, all but one of which are on the coast. Using the abundance of sea water as a source, this approach seeks to “climate proof” our cities’ water supplies.




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It’s hard to believe now that as recently as 2004 all Australian capital city water authorities relied on surface water storage dams or groundwater for drinking water supplies. Since Perth’s first desalination plant was completed in 2006, Australian capital cities have embraced massive seawater desalination “water factories” as a way to increase water security.

Perth and Adelaide have relied most on desalination to date. Canberra, Hobart and Darwin are the only capitals without desalination.

The drought that changed everything

From the late 1990s to 2009 southeastern Australia suffered through the Millennium Drought. This was a time of widespread water stress. It changed the Australian water industry for ever.

All major water authorities saw their water storages plummet. Melbourne storages fell to as low as 25% in 2009. The Gosford-Wyong water storage, supplying a fast-growing area of more than 300,000 people on the New South Wales Central Coast, dropped to 10% capacity in 2007.

These were familiar issues in locations such as Perth, where the big dry is epic. For more than four decades, the city’s residents have been watching their supply of surface water dwindle. Remarkably, only about 10% of Perth’s water now comes from this source.

Perth’s two desalination plants have a combined output of up to 145 billion litres (gigalitres, GL) a year. That’s nearly half the city’s water needs. Both have remained in operation since they were built.




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Modern industrial-scale desalination uses reverse osmosis to remove salt and other impurities from sea water. Water is forced under high pressure through a series of membranes through which salt and other impurities cannot pass.

Design, construction and maintenance costs of these industrial plants are high. They also use massive amounts of electricity, which increases greenhouse gas emissions unless renewable energy sources are used.

Another concern is the return of the excess salt to the environment. Australian studies have shown minimal impact.




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Just as many of the massive new desalination factories were completed, and proudly opened by smiling politicians, it started raining. The desalination plants were switched off as storages filled. However, water consumers still had to pay for the dormant plants to be maintained – hundreds of millions of dollars a year in the case of the Melbourne and Sydney plants.

Bringing plants out of mothballs

Now drought has returned to southeast Australia. Once again, many capital city water storages are in steep decline. So what is the response of water authorities in the desal age? Not surprisingly, more desalination is their answer.

One by one the desalination plants are being switched back on. Sydney has just begun the process of restarting its plant, which was commissioned in 2010. Adelaide has plans to greatly increase the modest output from its plant this year. The Gold Coast plant, which can also supply Brisbane, is operating at a low level in “hot standby” mode.

After a dry winter, Melbourne Water is expected to advise the Victorian government to make the largest orders for desalinated water since its plant, able to produce 150GL a year, was completed in December 2012. Mothballed for more than four years, it supplied its first water to reservoirs in March 2017. The previously forecast need for 100GL in 2019-20 (annual orders are decided in April) is almost one-quarter of Melbourne’s annual demand. Plant capacity is capable of being expanded to 200GL a year.

When bushfires recently threatened Victoria’s largest water storage, the Thomson dam, the government said desalinated water could be used to replace the 150GL a year taken from the dam.

Sydney’s plan for future droughts is to double the output of its desalination plant from 250 million litres (megalitres, ML) a day to 500ML a day. This would take its contribution from 15% to 30% of Sydney’s water demand.

Perth, Adelaide, Melbourne, Brisbane and the Gold Coast already have the capacity to supply larger proportions of their populations with desalinised water as required.

What about inland and regional settlements across Australia? Large-scale desalination plants may not viable for Canberra and other inland centres. These regions would require sufficient groundwater resources and extraction may not be environmentally sound.

How much, then, do we pay for the water we use?

The plants supplying our biggest cities cost billions to construct and maintain, even when they sit idle for years.

The Australian Water Association estimates the cost of supplying desalinated water varies widely, from $1 to $4 per kL.

In fact, water costs in general vary enormously, depending on location and how much is used. The pricing structures are about as complex as mobile phone plans or health insurance policies.

The highest price is in Canberra where residents pay $4.88/kL for each kL they use over 50kL per quarter. The cheapest rate is Hobart’s $1.06/kL.

The issue of water pricing leads on to the question of what happened to the alternative strategies – recycling and demand management – that cities pursued before desalination became the favoured approach? And how do these compare to the expensive, energy-hungry process of desalination? We will consider these questions in our second article.


This article has been updated to clarify the status of advice on Melbourne’s use of desalinated water.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University and Jason Reynolds, Research Lecturer in Geochemistry, Western Sydney University

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