Australia’s pristine beaches have a poo problem



Raw sewage from 3,500 people in Sydney’s affluent eastern suburbs is discharged directly into the ocean.
Will Turner/Unsplash

Ian Wright, Western Sydney University; Andrew Fischer, University of Tasmania; Boyd Dirk Blackwell, University of Tasmania; Qurratu A’yunin Rohmana, University of Tasmania, and Simon Toze, CSIRO

Australians love our iconic coastal lifestyle. So many of our settlements are spread along our huge coastline. Real estate prices soar where we can catch a view of the water.

But where there are crowded communities, there is sewage. And along the coast it brings a suite of problems associated with managing waste, keeping the marine environment healthy, and keeping recreational swimmers safe.




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Sewage is not a sexy topic. People often have an “out of sight, out of mind” attitude. But where does sewage go, and is it treated and disposed of in the waters that we Australians love?

The bigger the coastal community, the bigger the volume of sewage. Disposal of human waste into the ocean might solve one problem, but we now realise that the “waste” is as precious as the ocean it pollutes.

We should be treating and recycling sewage to a drinkable level.
shutterstock

Understanding the problem from a national perspective

Such problems play out continuously along our coastline. Each isolated community and catchment issue arises and is resolved, often in ignorance of and isolation from similar issues somewhere else.

At present, places where sewage impacts are generating community concern include Merimbula, Warrnambool and, perhaps most bizarrely, Vaucluse and Diamond Bay in Sydney’s affluent eastern suburbs.

It’s hard to believe this location has raw and untreated sewage from 3,500 people discharged directly into the Tasman Sea. Sydney Water pledged in 2018 to fix this unsightly pollution by transferring the flow to the nearby Bondi sewage treatment plant.

Community group Clean Ocean Foundation has worked with the Marine Biodiversity Hub to start the process of viewing outfall pollution – where a drain or sewer empties into the sea – as part of a bigger picture. It’s a first step towards understanding from a national perspective.




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Together they have produced the National Outfall Database to provide the first Australia-wide comparison.

The best and worst offenders

Previously the information available to the public was sketchy and often not easily accessed. The database shows how differently Australia manages coastal sewage with information on the outfalls.

Clean Ocean Foundation CEO John Gemmill said:

Water authorities in the main do a great job with severe funding constraints. But they can be reticent to divulge information publicly.

One authority, suspicious of the research project, initially refused to give the location of the outfall, claiming it would be vandalised by enraged “surfies and fishermen”.

Sydney has Australia’s biggest outfall. It provides primary treatment at Malabar, New South Wales, and serves about 1.7 million people. The outfall releases about 499 megalitres (ML) per day of treated sewage, called “effluent”.

That’s about eight Olympic-sized swimming pools of effluent an hour. It is discharged to the Pacific Ocean 3.6 kilometres from the shoreline at a depth of 82 metres.

The cleanest outfall (after sustained advocacy over decades from the Clean Ocean Foundation) is Boags Rock, in southern Melbourne. It releases tertiary-treated sewage with Class A+ water. This means the quality is very suitable for reuse and has no faecal bacteria detected (Enterococci or E.coli).

Recycling sewage

Treated sewage is 99% water. The last 1% is what determines if the water will harm human and environmental health. Are we wasting a precious resource by disposing of it in the ocean?

As desalination plants are cranking up in Sydney and Melbourne to extract pure water from salty ocean, why shouldn’t we also recycle sewage?




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Clean Ocean Foundation has released a report showing it would pay to treat sewage more thoroughly and reuse it. This report finds upgrading coastal sewage outfalls to a higher level of treatment will provide tens of billions of dollars in benefits.

Industry analysis suggests that, for a cost outlay of between A$7.3 billion and A$10 billion, sewage treatment upgrades can deliver between A$12 billion and A$28 billion in net benefits – that is, the financial benefits above and beyond what it cost to put new infrastructure in place.

Then there are non-economic benefits such as improved ecological and human health, and improved recreational and tourism opportunities by use of suitable recycling processes.

What the rest of Australia can learn from WA

Clean Ocean Foundation president Peter Smith said Australia’s key decision-makers now, more than before, have a “golden opportunity” to adopt a sea change in water reform around coastal Australia based on good science and sound economic analysis.

In the context of the drought of southeast Australia, recycling water from ocean outfalls is an option that demands further debate.




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As expensive desalination plants are switched on, Sydney proposes to double the size of its desalination plant – just a few kilometres from massive ocean outfalls that could provide so much recycled water. And to our shame, NSW ocean outfalls are among the lowest in standards of treatment.

Western Australia, on the other hand, leads the push to recycle wastewater as it continues to struggle with diminishing surface water from climate change.

In fact, in 2017 the Water Corporation announced massive investment in highly treated sewage being used to replenish groundwater supplies. Perth now sources 20% of its drinking water from groundwater, reducing its reliance on two desalination plants. A key factor was successful engagement with affected communities.

The discharge of poorly treated sewage to rivers, estuaries and oceans is a matter of national environmental significance and the Commonwealth should take a coordinating role.

Our oceans do not respect state boundaries. The time is ripe for a deliberate national approach to recycling sewage and improved systems to manage outfalls.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University; Andrew Fischer, Senior Lecturer, University of Tasmania; Boyd Dirk Blackwell, Adjunct Researcher, University of Tasmania; Qurratu A’yunin Rohmana, Research Analyst, University of Tasmania, and Simon Toze, Senior Principal Research Scientist, CSIRO

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

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We asked people to do climate change maths. Their answers depended on their politics


Will J Grant, Australian National University

In an ideal world, people would look at issues with a clear focus only on the facts. But in the real world, we know that doesn’t happen often.

People often look at issues through the prism of their own particular political identity – and have probably always done so.

However, in an environment of fake news, filter bubbles and echo chambers, it seems harder than ever to get people to agree about simple facts.

In research published today in Environmental Communication, my colleague Matthew Nurse and I report that even some of the smartest among us will simply refuse to acknowledge facts about climate change when we don’t like them.




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Skin cream versus climate change

The research took place just before Australia’s 2019 federal election.

We asked 252 people who were planning to vote for the Greens and 252 people who were planning to vote for One Nation to consider some data we’d put together. To understand that data, they would need to do some mental maths, just like you would when looking at a typical scientific report.

While there was no significant difference in the mathematical ability between the two groups of voters overall, it seemed that political affiliations can have an impact on how people answered a mathematical question, depending on the subject.

For example, in one experiment we told participants that data in the scientific report was about whether a new skin cream would cure a rash, as shown below.

We asked them to indicate whether the experiment shows that using the new cream is more likely to make the skin condition better or worse. Participants in our study got the correct mathematical answer 48% of the time.

However, when we showed them exactly the same data but said it was about whether closing coal-fired power stations would significantly reduce carbon dioxide emissions in the local area (by 30% or more), we got a very different set of answers.

For example, when the report showed CO₂ emissions would go down significantly, only 27% of One Nation supporters got the right answer.

When the report showed CO₂ emissions would not significantly go down, only 37% of Greens voters got it right.

So it seems our participants were less likely to answer a question correctly when it went against their political ideology.




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Spilt people according to maths ability

But what follows is really the interesting bit.

We decided to find out whether numeracy – maths ability – played a role in people getting the wrong answers. First, we looked at those with below-average numeracy.

We found many of these people just gave their preferred, ideologically aligned answers when it came to the climate change question. This is a well-known effect called motivated reasoning.

But surely the more numerate groups of people, those better at maths, would fare better? Well, not really.

The groups of people with above-average numeracy sometimes did worse than the less numerate groups. Some did no better than chance at 50%, and some did far, far worse than that, as the graph below shows.

More numerate people are more polarised about climate change data.
Matt Nurse, Author provided

When we showed people reports about CO₂ emissions, the more numerate people were much more politically polarised than any other group. For example, the participants considered a report showing that CO₂ would go down significantly, a One Nation supporter with a numeracy score of seven (out of nine) was only 5% as likely to provide the correct answer as a Greens supporter in the same numeracy category.

Motivations change brain function

This is counterintuitive, but this isn’t the first study to reveal this effect.

These findings build on research previously done by a Yale professor, Dan Kahan. The phenomenon is a type of motivated reasoning called motivated numeracy.

While Kahan’s previous research focused on the politically polarising issue of gun control in the United States, some people suggested the same thing might happen with other topics, particularly climate change.




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Our research is the first to confirm this.

These findings build on the theory that your desire to give an answer in line with your pre-existing beliefs on climate change can be stronger than your ability or desire to give the right answer.

In fact, more numerate people may be better at doing this because they are have more skills to rationalise their own beliefs in the face of contradictory evidence.

So what?

You might ask whether it really matters if people sometimes get the wrong answer on questions like this.

We’d argue yes, it does matter. Successful democracies rely on a majority of voters being able to identify and understand risks, and make the appropriate voting choices.

If people remain entrenched in their ideological corners when threats come along, and are unwilling to face facts, societal problems can fester, potentially becoming much more difficult to resolve later.

Just imagine scientists had discovered human activity was damaging our atmosphere. They said this problem would cause Earth’s climate to get hotter and threaten our livelihoods. Politicians and the people they represented saw this as a legitimate issue worth acting on, regardless of their political views. Imagine the world united to fix this problem, even though it would cost a lot of money.

In fact, we don’t need to imagine too much, as this isn’t just a hypothetical situation. It actually happened when scientists found evidence the use of industrial chemicals was depleting the ozone layer.

In 1987, for the first and only time, all 197 members of the United Nations agreed to sign the Montreal Protocol regulating the man-made chemicals that destroy the ozone layer. More than 30 years later we can measure the benefits of this agreement in our planet’s atmosphere.

A matter of science, not politics

Unlike the current climate change debate, people largely saw this risk as a matter of science, not politics.

But it seems people are increasingly encouraged to see risks like this through a political frame. When this happens, facts can become irrelevant because no matter how smart people are, many will simply deny the evidence to protect their side of the political debate.




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Societies need to make good choices for their survival and those choices need to be based on facts, regardless of whether everyone likes them or not.


This research was conducted by Matthew Nurse as part of a master’s thesis at the Australian National Centre for the Public Awareness of Science.The Conversation

Will J Grant, Senior Lecturer, Australian National Centre for the Public Awareness of Science, Australian National University

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