Our new research compared the level of mercury pollution in the Hunter Valley in New South Wales and the Latrobe Valley in Victoria.
And we found power stations in the Latrobe Valley emit around 10 times more mercury than power stations in the Hunter Valley. Indeed, the mercury level in the Latrobe Valley environment is 14 times higher than what’s typically natural for the region.
So why is there such a stark difference between states? Well, it has a lot to do with regulations.
Following a NSW requirement for power stations to install pollution control technology, mercury levels in the environment dropped. In Victoria, on the other hand, coal-fired power stations continue to operate without some of the air pollution controls NSW and other developed countries have mandated.
To minimise the safety risks that come with excessive mercury pollution, coal-fired power stations in all Australian jurisdictions should adopt the best available technologies to reduce mercury emissions.
A dangerous neurotoxin
Mercury is a neurotoxin, which means it can damage the nervous system, brain and other organs when a person or animal is exposed to unsafe levels.
Coal naturally contains mercury. So when power stations burn coal, mercury is released to the atmosphere and is then deposited back onto the Earth’s surface. When a high level of mercury ends up in bodies of water, such as lakes and rivers, it can be transferred to fish and other aquatic organisms, exposing people and larger animals to mercury that feed on these fish.
Mercury does not readily degrade or leave aquatic environments such as lakes and rivers. It’s a persistent toxic element — once present in water, it’s there to stay.
The amount of mercury emitted depends on the type of coal burnt (black or brown) and the type of pollution control devices the power stations use.
The Latrobe Valley stations in Victoria burn brown coal, which has more mercury than the black coal typically found in NSW. Despite this, Victorian regulations have historically not placed specific limits on mercury emissions.
While bag filters alone fall short of the world’s best practices, they can still be effective. In fact, after bag filters were retrofitted to Hunter Valley’s Liddell power station in the early 1990s, mercury deposition in the surrounding environment halved.
This is what’s been adopted across North America and parts of Europe. It not only filters out mercury, but also removes sulphur dioxide, nitrogen oxides and other toxic air compounds.
Using lake sediments to see into the past
Lake sediments can capture mercury deposited from the atmosphere and from surrounding areas. Sediments that contain this mercury accumulate at the bottom of lakes over time — the deeper the sediment, the further back in time we can analyse.
We took sediment samples from lakes in the Latrobe and Hunter valleys, and dated them back to 1940 to get a historical record of mercury deposition.
This information can help us understand how much naturally occurring mercury there was before coal-fired power stations were built, and therefore show us the impact of burning coal.
From these records, we found the adoption of bag filters in the Hunter Valley corresponded with mercury depositions declining in NSW from the 1990s.
In contrast, in Victoria, where there’s been no such requirement, mercury emissions and depositions have continued to increase since Hazelwood power station was completed in 1971.
What do we do about it?
In March, the Victorian government announced changes to the regulatory licence conditions for brown coal-fired power stations. Although mercury emissions allowances have been included for the first time, they’re arguably still too high, and there’s no requirement to install specific pollution control technologies.
There’s a risk this approach won’t reduce mercury emissions from existing levels. Victoria should instead consider more ambitious regulations that encourage the adoption of best practice technology to help protect local communities and the environment.
Another vital step toward protecting human health and the environment from mercury is for the federal government to ratify the Minamata Convention on Mercury, an international treaty to protect human health and the environment from mercury.
Ratifying the convention will oblige state and federal governments to develop and implement a strategy to reduce mercury emissions, including from coal-fired power stations across Australia. And this strategy should include rolling out effective technologies — our research shows it can make a big difference.
The authors acknowledge Lauri Myllyvirta from the Centre for Research on Energy and Clean Air for her contributions to this article.
This species, Dendronephthya australis, looks like a purple cauliflower due to its pink-lilac stems and branches, crowned with white polyps.
The coral primarily occurs at only a few sites in Port Stephens, New South Wales, and is a magnet for divers and underwater photographers. But sand movements, boating and fishing have reduced the species’ population dramatically.
Recent flooding in NSW compounded the problem – in fact, it may have reduced the remaining coral population by 90%. Our recent research found cauliflower soft coral may become extinct in the next decade unless we urgently protect and restore it.
Lilac underwater gardens
Cauliflower soft corals are predominantly found in estuarine environments on sandy seabeds with high current flow. They rely on tidal currents to transport plankton on which they feed.
The species is most commonly found in the Port Stephens estuary, about 200 kilometres north of Sydney. It’s also found in the Brisbane Water estuary in NSW, and has been found sporadically in other locations south to Jervis Bay.
The coral colonies form aggregations or “gardens”. At Port Stephens, these gardens are the preferred habitat for the endangered White’s seahorse and protected species of pipefish. They also support juvenile Australasian snapper, an important species for commercial and recreational fishers.
In recent months, the cauliflower soft coral has been listed as endangered in NSW and nationally.
Scientists first mapped the distribution of the cauliflower soft coral in 2011. They found none of the biggest colonies in the Port Stephens estuary were protected by “no take” zones – areas where fishing and other extractive activities are banned.
In research in 2016, we found a sharp decline in the extent and distribution of cauliflower soft coral.
Our recent study examined the problem in more detail. It involved mapping the southern shoreline of Port Stephens, using an underwater camera towed by a vessel.
We found the cauliflower soft coral in the Port Stephens estuary has declined by almost 70% over just eight years. It now occurs over 9,300 square metres – down from 28,600 square metres in 2011.
Our subsequent modelling sought to identify what was driving the corals’ decline. We found a correlation between coral loss and sand movements over the last decade.
Human changes to shorelines, such as marina developments, have changed the dynamic of currents across the estuary. For example, previous research found a large influx of sand from the western end of Shoal Bay smothered cauliflower soft coral colonies at two nearby locations. As of 2018, those colonies had disappeared completely.
While diving as part of the project, we identified other causes of damage to the coral. Dropped boat anchors and the installation of moorings had damaged some colonies. Others were injured after becoming entangled in fishing line.
It is possible that disease, and pollution or other water quality issues, may also be contributing to the species’ decline.
Then the floods hit
Some 18 months after our most recent mapping, cauliflower soft corals suffered yet another blow. Major flooding in NSW in March this year caused a massive amount of fresh water to discharge from the Karuah River into the Port Stephens estuary, where sea water is dominant. Fresh water can kill cauliflower soft corals.
Following the floods, we conducted exploratory dives at locations where the cauliflower soft corals had been thriving at Port Stephens. We found much of the coral had disintegrated and disappeared. In fact, we estimated as much as 90% of the remaining cauliflower soft coral population was gone.
We plan to remap the estuary in the coming weeks, and feel confident our initial estimates will be close to the mark. If so, this means less than 5% of the species area mapped in 2011 now remains.
The floods also devastated kelp forests and other canopy-forming habitats in the estuary. Further work by scientists at the NSW Department of Primary Industries is underway to quantify these losses and monitor the recovery.
The cauliflower soft coral urgently needs protecting. This will require ongoing, coordinated research and management.
Clearly, action must be taken to reduce threats such as anchoring, fishing, and development that may magnify sand movement.
Best-practice rehabilitation is also needed. This may involve rearing the coral off-site and transplanting it into suitable habitat. Such trials at Port Stephens have shown promising signs.
Human activities are causing species loss at an alarming rate. We must do everything in our power to prevent the extinction of the cauliflower soft coral, and other threatened species, to preserve the balance of nature and its ecosystems.
Don Driscoll, Deakin UniversityFeral horses are a catastrophic problem for the environment, particularly in the high country that crosses the New South Wales and Victoria border. To deal with this growing issue, the Victorian government has released a draft feral horse action plan, which is open for comment until April 23.
It comes after Victoria’s old action plan from 2018 proved ineffective, with feral horse numbers increasing in the most recent counts in 2019. This is similar to New South Wales’ current performance, where feral horses are legally protected and numbers are essentially unmanaged.
This new Victorian plan has flaws, but it’s still likely to perform better than the old plan (and the very low benchmark set by NSW), as it generally aims to deploy evidence-based management of national parks.
As Victoria gets on top of its feral horse problem, NSW will be left further behind with a degrading environment and rising costs of horse management.
Damage from feral horses could worsen as ecosystems recover from the extensive 2019-20 eastern Australian bushfires. Horse grazing could delay animals’ habitat recovery and horse trampling could exacerbate stream degradation after fires.
In fact, there are 24 species that need protection from feral horses after the fires, as identified by the Australian government’s wildlife and threatened species bushfire recovery expert panel in September.
All of this ecosystem destruction translates into substantial economic costs. Frontier Economics released a report in January this year showing the potential benefits of horse control in Kosciuszko National Park was A$19-50 million per year. The benefits accrue through improved recreational opportunities, improved water quality and reduced car crashes involving feral horses.
In contrast, horse control could cost as little as A$1 million per year and up to $71 million, depending on the methods used. Frontier Economics concluded the costs that are incurred by keeping feral horses far outweigh the cost of eradication.
remove isolated populations on the Bogong High Plains within three years and prevent new populations from establishing
contain and reduce feral horses in the eastern Alps by removing 500 horses in the first year
use the most humane, safe and effective horse control methods.
The first aim makes complete sense. Removing small populations will always be more humane, cheaper and better for the environment than leaving them uncontrolled.
The second aim is perplexing. Based on 2019 surveys, the draft action plan says there are approximately 5,000 horses in the eastern Alps and the population is growing at 15% per year. If the government continues to remove 500 horses per year after the first year, it could see the population rise to more than 9,000 over ten years, despite culling 5,000 horses in that time.
In contrast, removing 2,000 horses per year could see the population controlled within three years. Reducing horse numbers rapidly results in the fewest horses having to be culled in the long term.
The third aim of the Victorian draft action plan gives appropriate and strong emphasis to animal welfare. Controlling horse numbers can be morally challenging, and requires a clear understanding of the trade-offs.
Without horse control, native animals are killed when their habitat is destroyed, unique Australian ecosystems are degraded, horses themselves starve or die of thirst in droughts, and the economic costs of inaction escalate. To avoid these costs, horse numbers must be reduced by culling.
This is the grim reality, but with careful attention to animal welfare, the draft strategy will ensure horse control is managed humanely, with control methods based on evidence rather than hyperbole.
Money wasting in NSW
Victoria’s plan is in stark contrast to the NSW government’s approach. In 2018, the NSW government passed the so-called “brumby bill”, which protects feral horses in Kosciuszko National Park.
The current method of control in NSW is to capture the horses and transport them to an abattoir if they cannot be re-homed. But evidence shows culling has fewer animal welfare concerns than this method.
And in the latest round of money-wasting horse management, the NSW government trapped 574 horses over the past year, but released 192 females and foals back into the park. If the program is aimed at reducing horse numbers, releasing the most fertile animals back into the population is counter-productive.
What’s more, removing 300-400 horses per year has little impact on overall numbers. There are around 14,000 horses in Kosciuszko National Park, with a growth rate of 23% per year. This means more than 3,000 horses must be removed just to prevent the population from getting bigger.
The high country without feral horses
If the Victorian draft plan can be improved to invest in rapid horse reduction and ecosystem restoration, we can expect to see quagmires created by trampling horses return to functioning ecosystems and the recovery of threatened species.
Stream banks can be stabilised and then dense grass tussocks and sedges will return, creating homes for threatened skinks, crayfish and the Tooarrana broad-toothed rat.
While Kosciuszko’s alpine ecosystems continue to decline under the NSW government’s political impasse, the Victorian Alps will become the favoured destination for tourists who want to see Australia’s nature thriving when they visit national parks.
Replacing cars that run on fossil fuels with electric cars will be important in meeting climate goals – road transport produces more than 20% of global greenhouse gas emissions. But there are obstacles to wider uptake, particularly in Australia.
Too much of the debate about these vehicles revolves around abstract, technical calculations and assumptions about cost and benefit. Tariffs, taxes and incentives are important in shaping decisions, but the user experience is often overlooked. To better understand this we took a Tesla on a road trip from Sydney through some regional towns in New South Wales.
We soon found “range anxiety” is real. That’s the worry that the battery will run out of power before reaching the destination or a charging point. It’s often cited as the most important reason for reluctance to buy an electric vehicle.
Even as prices come down and hire and share options become more widespread, range anxiety about electric vehicles is hindering their wider uptake. We found it can largely be overcome through a range of strategies readily available now.
Lessons from our road trip
The first is simply to accumulate driving experience with a particular vehicle. Teslas promise a far simpler machine with fewer moving parts, but also incredibly sophisticated sensing and computational technology to help control your trip. This means you need to get a feel for the algorithms that calculate route and range.
These algorithms are black boxes – their calculations are invisible to users, only appearing as outputs like range calculations. On our trip, range forecasts were surprisingly inaccurate for crossing the Great Dividing Range, for example.
Second, we found it very helpful to connect with other electric vehicle users and share experiences of driving. Just like any new technology, forming a community of users is a good way to gain an understanding of the vehicle’s uses and limits. Owner associations and lively online groups such as Electric Vehicles for Australia make finding fellow enthusiasts easy.
This connection can also help with the third strategy. It involves developing an understanding of how companies like Tesla control their vehicles and issue “over the air” software updates. If these specify different parameters for acceptable battery charge, that can change the vehicle’s range.
Understanding what is involved for users is also crucial to the environmental benefits of electric vehicles. Their sustainability isn’t just a function of taxes and technologies. The practices of people driving electric cars matter too.
You learn with experience what efficient driving requires of you. You can also work out how your charging patterns could match solar generation at home, for those lucky enough to have rooftop PV panels.
These vehicles can deliver significant environmental benefits. They produce zero tailpipe emissions, reducing both local air pollution and global greenhouse gas emissions.
Regenerative braking also reduces brake particulate emissions. That’s because the electric motor operating in reverse can slow the car while recharging its battery.
Electric vehicles won’t cure all ills
Switching from internal combustion to electric cars won’t address all the problems of our current car-based system. Some, such as road congestion, could get worse.
Congestion and the costs of providing and maintaining roads, parking and associated infrastructure will still create enormous social, economic and environmental burdens. Electric vehicles need to be part of a much wider transformation – especially in urban areas where other transport options are available.
Longer distances and lower densities make walking, cycling and public transport more challenging in rural and regional areas. Better support for electric vehicles, particularly chargers, could make a significant difference here.
These vehicles can help rural and regional areas in other ways too. Many holiday towns rely on tourist incomes but their electricity supply is at the mercy of long thin power lines that run through bushland. Electric vehicles could potentially help with this problem: when parked they can feed power back into the grid.
Regional economic planning that supports visits by electric vehicle drivers can reduce the need to invest in energy generation or battery systems. There are huge opportunities to integrate electricity planning and the (re)building of bushfire-affected towns, which a trial in Mallacoota will explore.
Pooled together, the batteries of an all-electric national vehicle fleet could provide power equivalent to that of five Snowy 2.0s. This would boost energy security and flexibility.
In 2017, I came across an extraordinary document in Sydney’s Mitchell Library: a handwritten list of 178 Aboriginal place names for Dyarubbin, the Hawkesbury River, compiled in 1829 by a Presbyterian minister, the Reverend John McGarvie. I was stunned. I stared at the screen, hardly believing my eyes.
After years of research, my own and others, I thought most of the Aboriginal names for the river were lost forever, destroyed in the aftermath of invasion and dispossession. Yet, suddenly, this cache of riches.
I could see McGarvie had taken a lot of care with this list, correcting spelling and adding pronunciation marks. The names appear in geographic order, so they also record where he and his Darug informant/s travelled along the riverbanks. Perhaps most important of all, McGarvie often included locational clues, like settlers’ farms, creeks and lagoons.
An extraordinary idea dawned on me: what if we could restore these names to their places on the river? And then: what if these beautiful, rolling words — like Bulyayorang and Marrengorra and Woollootottemba — came back into common usage?
Place names have enormous significance in Aboriginal society and culture. As in all societies, they signal the meanings people attach to places, they encode history and geography, they are way-finding devices and common knowledge. Place names are crucial elements of shared understandings of Country, history, culture, rights and responsibilities.
Often place names are parts of larger naming systems — they name places on Dreaming tracks reaching across Country. Singular names can also embed the stories of important events and landmarks involving Ancestral Beings in places and memory. Anthropologist and linguist Jim Wafer points out their use in songs, which are memory devices, or “audible maps … travelling song cycles that narrate mythical journeys”.
Dyarubbin, the Hawkesbury River, flows through the heart of a vast arc of sandstone Country encircling Sydney and the shale-soil Cumberland Plain on the east coast of New South Wales. The river has a deep human history, one of the longest known in Australia.
The ancestors of Darug, Darkinyung and Gundungurra people have lived in this region for around 50,000 years. Their history, culture and spirituality are inseparable from their river Country. A mere two centuries ago, ex-convict settlers took land on the river and began growing patches of wheat and corn in the tall forests. Darug men and women resisted the invasion fiercely and sometimes successfully.
Between 1794 and 1816, Dyarubbin was the site of one of the longest frontier wars in Australian history. Invasion and colonisation kicked off a slow and cumulative process of violence, theft of Aboriginal children, dispossession and the ongoing annexation of the river lands.
Yet despite this sorry history, Dyarubbin’s people managed to remain on their Country, and they still live on the river today.
McGarvie’s list contrasts strikingly with the modern landscapes of the Hawkesbury and Western Sydney. Once, every place on this river and its tributaries had an Aboriginal name. Now only a handful survive on maps and in common usage.
With some important exceptions, the Traditional Owners, the Darug, rarely see themselves represented in key heritage sites, or in the everyday reminders and triggers of public memory – like place names.
Yet Western Sydney is now home to one of the biggest populations of Darug and other Aboriginal people in Australia. Could McGarvie’s list be a way to begin to shift the shape of our landscapes towards a recognition of Darug history and culture?
Living on Country
This idea stayed with me, so I contacted Darug knowledge-holders, artists and educators Leanne Watson, Erin Wilkins, Jasmine Seymour and Rhiannon Wright: the response was instant and enthusiastic. We designed the project together and were thrilled when it won the NSW State Library’s Coral Thomas Fellowship
The project’s Darug researchers want most of all to research, record and recover environmental and cultural knowledge and raise awareness of Darug presence and history in the wider community.
Because the Darug history of Dyarubbin is continuous, the project includes an oral history component, recording 20th century Darug voices and stories of the river.
Looking back, it seems uncanny that McGarvie’s list reappeared when it did — after all, we are in the midst of an extraordinary period of Aboriginal cultural renewal and language revitalisation.
It was obvious that McGarvie’s words could be more than a list of names: it could be the key to a bigger story about the Dyarubbin, the Darug history that was lost, submerged below what historian Tom Griffiths calls “the white noise of history making”.
But to do this, we needed to put the words in their wider context: we needed to see the river whole. So, besides reconnecting the list to Traditional Owners, the project explores Dyarubbin’s history, ecology, geography, archaeology and languages.
Early maps showing the old river farms helped us work out where the Darug place names belong and digitally map them. They also record long-lost landscapes of swamps, lagoons and creeks — important places for Aboriginal people that have since been modified or disappeared altogether.
The “Returns of Aboriginal Natives” are lists of Aboriginal people living in New South Wales in the 1830s, including the groups who lived on various parts of Dyarubbin and its tributaries. Reverend McGarvie’s diaries show he knew many of these Darug people.
The letters and journals of Hawkesbury settlers are thoroughly colonial-centred, yet they contain hints about the ways Darug people continued to live on their Country throughout the 19th century.
For example, they befriended some of the settlers, like the Hall family at Lilburndale, and cultivated these relationships over generations. The Hall family papers in the Mitchell Library hold some powerful and poignant traces: store receipts for goods Darug people were purchasing from them, and lists of the work they did at Lilburndale.
The archaeological record for this region is astonishingly rich. Dyarubbin and its tributary Gunanday (the Macdonald River) are part of a much larger archaeological zone, reaching from the Blue Mountains and the Wollemi in the west, up to the Hunter Valley and Lake Macquarie in the north. Many of the major recorded archaeological sites have sacred, spiritual and ceremonial significance, especially those located on high places.
Closer to the river, Paul Irish’s archaeological mapping has revealed how much Darug cultural landscape survives today, within the “settler” landscape.
From Richmond in the south to Higher Macdonald in the north, the river corridors alone are lined with more than 200 archaeological sites, including engravings, grinding grooves and rock shelters, some with scores or hundreds of images in ochre, white clay and charcaol.
Perhaps the most important aspect of the project are the field trips — getting out on Country, following in the footstep of McGarvie and his Darug friends, to see how all of this comes together. For Aboriginal people especially, visiting Country is a spiritual experience: they sense past and present converging, and the presence of their Ancestors.
Words for Country
What about the words on McGarvie’s list? What can they tell us? Linguist Jim Wafer and I worked with the Darug team members on a glossary, scouring dictionaries of seven local and adjacent Aboriginal languages for glosses, or meanings.
Many of these remain tentative; some words have two possible glosses. This project is, after all, only the beginning of what will hopefully be a much longer journey of discovery.
Nevertheless, McGarvie’s list has unlocked a wealth of information as well as intriguing and suggestive patterns — the place names open a marvellous word-window onto the Darug world of Dyarubbin in late 1820s.
They can be roughly grouped in four interrelated and often overlapping categories: the natural world of plants and creatures, geography and landforms, stone and earth, salt and fresh water; the social world of corroboree and contest grounds, camps and places to source materials for tools and implements; a metaphoric pattern — using words for parts of the body (mouth, arm, finger, eyes) for places on the river; and names with spiritual meanings, signifying sacred places.
Are there larger patterns in McGarvie’s list of place names? Here again, mapping the names, relocating them on Country, revealed something about how Darug people thought of Dyarubbin: as a series of zones, each which particular characteristics.
For example, on the west side of the river between Sackville and Wilberforce are 16 named lagoons or words meaning lagoons, including four different words which appear to signify different types of lagoons: Warretya, Warang, Warradé, Warrakia.
It was Warretya (lagoon) Country. Rich in birdlife, fish, turtles, eggs and edible plants, lagoons were very important places for Darug people, especially women, who harvested the edible roots and shoots of water plants such as cumbungi, water ribbon and common nardoo.
There were lagoons on the opposite side of the river, too, but here the series of place names around Cattai Creek tell us that this was Dugga (thick brush/rainforest) Country.
Massive Riverflat forest once lined all of Dyarubbin’s alluvial reaches; in sheltered gullies this forest graded into rainforest. Other place names in this area suggest the tree species which grew in these forests: Boolo, coachwood, Tamangoa, place of Port Jackson figs, Karowerry, native plum tree, Booldoorra, soft corkwood. And there are places named for implements, like clubs (Kanogilba, Berambo), and fish spears (Mating), which may have been fashioned from the fine, hard timbers of some of these trees.
These Dugga place names suggest something significant about Dyarubbin’s human and ecological history, too. The settler invasion is often assumed to have completely destroyed earlier landscapes, converting the bush to cleared, farmed fields. But these tree and forest names suggest that parts of the great forests survived for over three decades, and that Darug people went on using them.
Perhaps most significant and evocative are the place names which signal sacred zones on Dyarubbin. There are two different words meaning “rainbow”: Dorumbolooa and Gunanday.
The great Eel Being
Both are located in places with dramatic cliffs and sharp river bends. These words are probably linked with Gurangatty, the great Eel Being, who is associated with rainbows, and who created the river and its valley in the Dreaming, leaving awesome chasms and sinuous bends in his wake. McGarvie’s list reconnects us with the sacred river.
Such words remind us of something obvious, and profound. If Aboriginal people are to be at the centre of their own stories, we need to look beyond European history and landscapes, beyond European knowledge and ways of thinking, and towards an Aboriginal sense of Country — the belief that people, animals, Law and Country are inseparable, that the land is animate and inspirited, that it is a historical actor.
Leanne Watson’s painting Waterholes, inspired by the project, expresses this sense of Country. Her painting represents the beautiful lagoons around Ebenezer near Wilberforce and all the nourishment and materials they offered people. Now we can name some of those lagoons: Boollangay, Marrumboollo, Kallangang.
What now? Two exhibitions are planned for 2021: one at the State Library of NSW, and the other at Hawkesbury Regional Gallery. Staff at NSW Spatial Services/the NSW Geographic Names Board have generously offered their skills and time to create a digital Story Map, which will allow readers to virtually explore Darug Dyarubbin.
A series of illustrated essays, or “story cycle”, to be published on the online Dictionary of Sydney at the State Library of New South Wales, will present more in-depth narratives. Ultimately, we plan to launch dual naming projects, which will restore these names to Dyarubbin Country.
These are truth-telling projects: they will tell the story of invasion, dispossession and frontier war. But they will also explore Darug history, culture, places and names, and the way Dyarubbin and its surrounding high lands still throb with spiritual meaning and power, and the “ancient sovereignty” of Aboriginal people.
Twenty years ago, UNESCO inscribed the greater Blue Mountains area on the World Heritage List for having “outstanding universal value”.
If you’ve travelled to the Blue Mountains, with its rugged sandstone cliff faces, hidden waterfalls and rich diversity of life, this value is undeniable. The Dharug and Gundungurra traditional owners long understood this value as they lived within and cared for Country (Ngurra) and, in turn, were nourished by it.
Last week, the International Union for Conservation of Nature (IUCN) — the official advisor to UNESCO — rated the site as being of “significant concern”, a drop from “good with some concerns”. It’s now in the second-lowest category.
The news may be grim, but there are signs of hope. Despite threats of climate change, bushfires and decades of pollution, efforts are being made to minimise lingering impacts, and results are encouraging.
Ancient trees and unique animals
The Greater Blue Mountains World Heritage Area covers just over one million hectares, divided into eight protected areas.
The largest protected area is Wollemi National Park (499,879 ha) in the north. This park is, famously, home to the last wild population of Wollemi Pine. These trees have a deeply ancient lineage tracing back to when the Earth’s land masses were all part of the supercontinent Gondwana over 100 million years ago.
The World Heritage area harbours 1,500 plant species, and 127 of them are rare or threatened. And in an outstanding example of the area’s uniqueness, it also contains more than 90 Eucalypt species — 13% of the global total.
The World Heritage area is also an important habitat for many rare and threatened animal species.
One celebrated seasonal visitor is the critically endangered regent honeyeater. Also under threat, and unique to the Blue Mountains, is the leura skink, which survives only in a handful of sensitive and vulnerable wetland communities.
In its new report, the IUCN lists eight current threats undermining the greater Blue Mountains area. The most worrying – those considered “very high threats” in the report — are climate change and bushfires.
The severe fires of last summer inflicted long-lasting damage to many Blue Mountains species that contribute to the unique biodiversity of the area. And climate change is an emerging environmental pressure threatening the delicate ecology of the region through rising temperatures and changes to rainfall.
The IUCN also rated invasive plant and animal species, such as foxes, feral cats, horses, cattle and deer, as a high threat. Mining and quarrying, habitat alteration and several specific aspects of climate change (storms, drought, temperature extremes) were also listed.
The IUCN also named potential threats from planned operations, including future noise pollution from the new international airport in Western Sydney. Another is the impact of periodic flooding from a proposal to raise the wall of Warragamba Dam for flood mitigation purposes.
Cleaning up their act
Climate change and bushfires require massive, coordinated national and international responses, but some major issues in the Blue Mountains can start to be resolved on relatively smaller scales.
For decades, the Blue Mountains have been flogged by a number of human pressures, such as an outdated sewage system from the City of the Blue Mountains and pollution from coal mining. While the environment hasn’t fully recovered, we’re pleased to see successes in the recovery efforts.
All Blue Mountains wastewater is now treated to a higher standard at Winmalee in the lower Blue Mountains and is released away from waterways in the World Heritage area.
Another important pressure in the Greater Blue Mountains Area is from coal mining, with UNESCO expressing concerns in 2001 about water pollution from mines, such as the one operated by Clarence Colliery.
This mine is in state forest adjacent to the World Heritage area boundary. Research from 2017 found wastewater discharging from the mine was severely contaminating water quality of the Wollangambe River and damaging the ecology for more than 20 kilometres.
For an internationally important site like this, which is home to more than 80,000 residents, all levels of government must adopt the concept of “planetary health”. This recognises that human health entirely depends on the health of natural systems and embraces Indigenous knowledge.
We’re pleased to see the Blue Mountains City Council is already on board. It recently announced plans to establish a planetary health leadership centre in Katoomba in partnership with universities and other educational institutions.
So while there is much to grieve, we can celebrate small successes in the Blue Mountains’ journey, which show it is indeed possible for a diverse array of parties and the broader community to work cooperatively, and start to better protect it.
Biomethane technology is no longer on the backburner in Australia after an announcement this week that gas from Sydney’s Malabar wastewater plant will be used to power up to 24,000 homes.
Biomethane, also known as renewable natural gas, is produced when bacteria break down organic material such as human waste.
The demonstration project is the first of its kind in Australia. But many may soon follow: New South Wales’ gas pipelines are reportedly close to more than 30,000 terajoules (TJs) of potential biogas, enough to supply 1.4 million homes.
Critics say the project will do little to dent Australia’s greenhouse emissions. But if deployed at scale, gas captured from wastewater can help decarbonise our gas grid and bolster energy supplies. The trial represents the chance to demonstrate an internationally proven technology on Australian soil.
What’s the project all about?
Biomethane is a clean form of biogas. Biogas is about 60% methane and 40% carbon dioxide (CO₂) and other contaminants. Turning biogas into biomethane requires technology that scrubs out the contaminants – a process called upgrading.
The resulting biomethane is 98% methane. While methane produces CO₂ when burned at the point of use, biomethane is considered “zero emissions” – it does not add to greenhouse gas emissions. This is because:
it captures methane produced from anaerobic digestion, in which microorganisms break down organic material. This methane would otherwise have been released to the atmosphere
it is used in place of fossil fuels, displacing those CO₂ emissions.
Biomethane can also produce negative emissions if the CO₂ produced from upgrading it is used in other processes, such as industry and manufacturing.
Biomethane is indistinguishable from natural gas, so can be used in existing gas infrastructure.
The Malabar project, in southeast Sydney, is a joint venture between gas infrastructure giant Jemena and utility company Sydney Water. The A$13.8 million trial is partly funded by the federal government’s Australian Renewable Energy Agency (ARENA).
Sydney Water, which runs the Malabar wastewater plant, will install gas-purifying equipment at the site. Biogas produced from sewage sludge will be cleaned and upgraded – removing contaminants such as CO₂ – then injected into Jemena’s gas pipelines.
Sydney Water will initially supply 95TJ of biomethane a year from early 2022, equivalent to the gas demand of about 13,300 homes. Production is expected to scale up to 200TJ a year.
Biomethane: the benefits and challenges for Australia
A report by the International Energy Agency earlier this year said biogas and biomethane could cover 20% of global natural gas demand while reducing greenhouse emissions.
As well as creating zero-emissions energy from wastewater, biomethane can be produced from waste created by agriculture and food production, and from methane released at landfill sites.
The industry is a potential economic opportunity for regional areas, and would generate skilled jobs in planning, engineering, operating and maintenance of biogas and biomethane plants.
Methane emitted from organic waste at facilities such as Malabar is 28 times more potent than CO₂. So using it to replace fossil-fuel natural gas is a win for the environment.
It’s also a win for Jemena, and all energy users. Many of Jemena’s gas customers, such as the City of Sydney, want to decarbonise their existing energy supplies. Some say they will stop using gas if renewable alternatives are not found. Jemena calculates losing these customers would lose it A$2.1 million each year by 2050, and ultimately, lead to higher costs for remaining customers.
The challenge for Australia will be the large scale roll out of biomethane. Historically, this phase has been a costly exercise for renewable technologies entering the market.
The global picture
Worldwide, the top biomethane-producers include Germany, the United Kingdom, Sweden, France and the United States.
The international market for biomethane is growing. Global clean energy policies, such as the European Green Deal, will help create extra demand for biomethane. The largest opportunities lie in the Asia-Pacific region, where natural gas consumption and imports have grown rapidly in recent years.
Australia is lagging behind the rest of the world on biomethane use. But more broadly, it does have a biogas sector, comprising than 240 plants associated with landfill gas power units and wastewater treatment.
In Australia, biogas is already used to produce electricity and heat. The step to grid injection is sensible, given the logistics of injecting biomethane into existing gas infrastructure works well overseas. But the industry needs government support.
Last year, a landmark report into biogas opportunities for Australia put potential production at 103 terawatt hours. This is equivalent to almost 9% of Australia’s total energy consumption, and comparable to current biogas production in Germany.
A clean way to a gas-led recovery
While the scale of the Malabar project will only reduce emissions in a small way initially, the trial will bring renewable gas into the Australia’s renewable energy family. Industry group Bioenergy Australia is now working to ensure gas standards and specifications are understood, to safeguard its smooth and safe introduction into the energy mix.
The Morrison government has been spruiking a gas-led recovery from the COVID-19 recession, which it says would make energy more affordable for families and businesses and support jobs. Using greenhouse gases produced by wastewater in Australia’s biggest city is an important – and green – first step.