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Can billions of litres of coal seam gas water be safely reinjected into the ground?
Water produced when coal seam gas (CSG) is extracted from below ground can be safely re-injected hundreds of metres underground, according to new CSIRO research.
Water is pumped out of coal seams to access the gas held within them. CSG in the Surat Basin, Australia, produces on average 70 gigalitres of water each year - a seventh of the water held in Sydney Harbour. What to do with this water is one of a number of concerns voiced by communities around CSG.
Our research shows that injecting large volumes of treated CSG-produced water at suitable locations within the Surat Basin is unlikely to cause any harm to groundwater quality.
However, to achieve this the water has to be treated adequately to eliminate the risk of polluting groundwater with arsenic – a generally immobile toxic element that occurs naturally in some of the rock formations being considered for re-injection.
Why re-inject CSG water anyway?In Queensland, the state government’s policy on managing “produced water”, also commonly known as “CSG water”, is to “encourage the beneficial use of CSG water in a way that protects the environment and maximises its productive use as a valuable resource”.
In many cases the most suitable and socially-accepted option is to treat the water, using reverse osmosis technology, and inject it into deep aquifers. The re-injected water can be used to top-up already stressed aquifers.
However, looking at similar projects around the world, especially from Florida, has shown that injecting clean water underground can sometimes mobilise naturally occurring contaminants such as arsenic.
When rainwater seeps underground and becomes groundwater it changes its composition. During the subsurface passage that can often take thousands of years the groundwater composition changes slowly to successively take on the characteristics of the rocks.
When water with a non-compatible composition is directly injected into deep aquifers, the injected water will also react with the rocks and therefore change its characteristics to one that is compatible with the new host rock. This occurs through the release of elements from the rocks, a process called mineral dissolution.
In addition, arsenic mobilisation can also occur by a process called desorption, in which case loosely-attached ions are released from mineral surfaces. Both processes may proceed until a new balance or “geochemical equilibrium” is established and both have the potential to mobilise toxic elements such as arsenic.
Testing the watersIn our new research, we analysed results from injection experiments at Reedy Creek and at Condabri, both located in the Surat Basin in Queensland, through computer models that can simulate groundwater flow and groundwater quality.
This analysis showed that if and how much arsenic is mobilised depends on the composition of the injected water. From the research we conclude that minimising arsenic release most importantly depends on oxygen being stripped from the water prior to injection of the CSG water.
During the research elevated arsenic levels have been found during a field experiment at one of the sites (Reedy Creek), for which both experiments and computer modelling suggest that arsenic release was triggered by the injected water.
However, computer modelling also demonstrated that this type of arsenic mobilisation could have been completely prevented by adjusting the pH of the injected water to the pH of the naturally-residing groundwater.
The experiments performed at the second research site at Condabri under different experimental conditions showed that arsenic concentrations in the groundwater increased substantially if the injected water was not stripped of oxygen.
When oxygen was not removed from the injected water this caused the dissolution of the naturally-abundant mineral pyrite, or “fool’s gold”. Arsenic is often embedded in trace amounts in this mineral.
What can we do?The findings from this research were used to guide the design requirements for the large-scale implementation of CSG water injection into the Precipice aquifer. During the treatment process all water is now deoxygenated prior to injection and the pH of the injected water is similar to the natural groundwater.
The Reedy Creek re-injection scheme is now successfully operating and injecting treated CSG water. Since starting the injection in 2015, over 10 gigalitres (GL) has been injected into the Precipice aquifer and the scheme is currently Australia’s largest treated water re-injection scheme.
As a result groundwater levels in parts of the Precipice aquifer have started to rise for the first time in the last few decades.
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This research received funding from National GISERA (National Gas Industry Social and Environmental Research Alliance). This is a collaborative vehicle established to undertake publicly-reported independent research addressing the social, economic and environmental impacts of Australia's onshorel gas industry. The governance structure for National GISERA is designed to provide for and protect research independence, integrity and transparency of funded research. Visit www.gisera.org.au for more information.
Is Fukushima still safe after the latest earthquake?
We all remember March 11, 2011, when the magnitude-9.0 Great East Japan earthquake triggered a 14-metre tsunami that flooded the Fukushima Daiichi nuclear power plant. Four of the six reactors on site were badly damaged, three suffering core meltdowns.
Also affected by the tsunami, but to a much lesser extent, were the four reactors at the Fukushima Daini nuclear power plant, roughly 11km further south. That site was partially flooded, but sufficient safety systems were still available to shut down and cool the reactors safely.
At 5.59 am local time on Tuesday the tsunami alarms sounded again, as a magnitude-6.9 earthquake 10km off the coast shook the area. Just over half an hour later the resulting tsunami hit the Fukushima coast – but this one was barely a metre high, and well below the height of the 5.7m seawall, meaning that Fukushima’s nuclear plants were spared another flood.
However, the earthquake caused a circulation pump in the used fuel cooling pond of Fukushima Daini reactor 3 to shut down. After checking the system, the pump was restarted after 99 minutes, and operator TEPCO said the plant had suffered no lasting damage.
The situation might have been more serious were it not for the fact that Fukushima Daini, like most of Japan’s nuclear power stations, has been out of action ever since the disaster at its neighbouring station prompted Japan to shut down all of its nuclear reactors for safety checking and upgrades.
Although all of Daini’s systems have since been restored, its reactors have not been restarted. All the fuel has been removed from the reactors and is stored in cooling ponds – which is where the circulation pump failed that normally pushes water through a heat exchanger for cooling.
Because of the low residual heat in the used fuel, the reported temperature rise was less than 1℃ during the 99-minute outage. Without cooling, the temperature of the cooling pool would be expected to rise by 0.2℃ per hour. It would therefore take more than a week without cooling before the normal operating range of 65℃ would be exceeded, and this would still be far below the fuel melting point of around 2,800℃.
There has been no reported damage from the latest earthquake at the Fukushima Daiichi plant where decommissioning work continues (although it was briefly stopped in response to the earthquake). As of 11am on Tuesday, plant parameters show reactor cooling systems operating normally with reactor temperatures of 20-25℃, again far below any dangerous levels. Again, the low amount of residual heat in the fuel means that any changes on loss of cooling are slow. This is in stark contrast to the situation in 2011 where loss of cooling to the operating reactors led to fuel melting in less than four hours.
Is Japan’s nuclear power coming back?Before the 2011 meltdowns, there were 54 nuclear power reactors operating in Japan. Since then, only three reactors have completed all of the required modifications and safety inspections and returned to operation, and one of these is currently shut down for routine refuelling. Currently 42 reactors will potentially be restarted, 24 of which are slowly going through the restart approval process.
The extent of modifications to avoid possible damage from tsunamis is illustrated by the work that Chubu Electric Power Company is carrying out at its Hamaoka nuclear power plant in Japan’s southeast Shizuoka prefecture. This year Chubu has completed construction of a huge seawall, 22m high and 1.6km long, which together with other safety upgrades will cost about 400 billion yen (A$4.9 billion).
After TEPCO faced accusations that it failed to take full account of the tsunami risk at Fukushima, Japan is clearly taking no chances next time around.
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Tony Irwin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.
Views on the Murray-Darling from across Australia
Justin Trudeau’s giant corporate giveaway | Martin Lukacs
A privatization spree in Canada could cost regular people billions, erode democracy and undermine the fight against climate change
While prime minister Justin Trudeau flogged our public assets last week, he had a soothing message: rest assured, we’ll be well-served by the private sector. Bankers and billionaires lined up to sound a note of confidence. “I think it’s unprecedented,” exclaimed Canada’s top business lobbyist John Manley. “A once-in-a-generation opportunity,” enthused Trudeau’s economic advisory council.
These corporate figures are rubbing their hands because Trudeau is about to put one of our great crises in their hands: the need for historic investment in the country’s infrastructure, for so long the domain of the state.
Continue reading...How Sadiq Khan aims to become London's most cycle-friendly mayor
In response to concerns from the former cycling commissioner, the deputy mayor for transport insists plans are on track
Sadiq Khan is committed to being the most cycling-friendly mayor that the capital has ever had – and is already delivering real results. However, there have recently been a number of inaccurate reports about his plans and I’d like to take this opportunity to set the record straight.
Making cycling safer and easier will be a significantly higher priority for Sadiq than it was for the previous administration.
Continue reading...Asian transport projects may thwart efforts to save world's tigers
WWF report states that infrastructure boom could lead to animals’ habitat being carved up, undoing years of progress
Thousands of kilometres of railways and roads planned across Asia risk dismantling progress made to save the world’s last tigers, conservationists have warned.
The WWF said an infrastructure boom in coming years will lead to the construction of 11,000km of new transport projects, carving up the big cat’s habitats and stopping them from travelling across the huge ranges they need.
Continue reading...Flooding around the UK – in pictures
The cleanup begins after a combination of Storm Angus and continued heavy rain have contributed to widespread flooding around the UK since Sunday
Continue reading...China emerges as global climate leader in wake of Trump's triumph
With the US president-elect threatening to withdraw from the Paris Agreement, Beijing is to ready to lead world’s climate efforts, reports Environment 360
In one of the more entertaining moments of COP22, the global climate conference held in Marrakech last week, the Chinese vice-foreign minister Liu Zhenmin, gave the absent US president-elect a short lesson in the history of climate diplomacy. Climate change, he explained, was not a Chinese hoax. In fact, long before the issue had been discussed behind the high vermillion walls of Zhongnanhai, China’s contemporary Forbidden City, it had been put on the global agenda by the Intergovernmental Panel on Climate Change in the 1980s, supported by Ronald Reagan and George Bush (senior).
Mounting international concern led eventually to the Kyoto Protocol, the first global agreement to try to limit climate change, signed by President Bill Clinton subsequently rejected by the US Congress. When President Obama’s administration formally entered the successor Paris Agreement in September this year, the president knew better than to try to seek endorsement from a hostile Congress. Yet the US has been present throughout, as the world grappled with how to distribute the burden of global action to ward off climate catastrophe, although its leadership has been, at best, intermittent. It has tended to resemble a temperamental adolescent, periodically playing the game, but intermittently flouncing off the field, its ball firmly under its arm.
Continue reading...Environmental hotspot
VW shifts focus to electric cars with US expansion plan
German carmaker seeks to revive fortunes after diesel scandal by becoming world leader in clean-energy vehicles
Volkswagen said it wants to be the world leader in electric cars by 2025 as it unveiled a major shift to clean-energy vehicles in the wake of the dieselgate emissions cheating scandal.
The US market, where the pollution crisis first erupted, will play a key role in the revamp, according to VW brand chief Herbert Diess. He announced a “comeback story” for the region, with plans for electric cars to be built in North America from 2021.
Continue reading...Dodo skeleton sells for £280,000 at auction
Fossil fuel divestment soars in UK universities
Britain leads world in campus action to pull funds from oil, gas and coal companies, due to climate change concerns
The number of British universities divesting from fossil fuels has leaped to 43, a quarter of the total. The surge means the UK leads the world in campus action to pull university funds from oil, gas and coal.
Financial institutions and charities are also divesting and at least $2.6tn (£2.1tn) of assets are covered by such pledges around the world. Scientists have shown that most fossil fuel reserves cannot be burned without dangerous climate change. Campaigners argue this makes fossil fuel companies bad investments on both moral and financial grounds.
Continue reading...Africa's biggest windfarm sparks controversy in the desert
Morocco’s ambitious plans for wind power in Western Sahara have drawn international praise - but are raising heckles in the disputed territory
Last week’s Marrakech climate summit shone a light on Morocco’s clean energy plans, which have drawn praise from around the world. At the heart of King Mohammed VI’s ambitions is a windfarm in the country’s south-west region, which, due to an expansion over the summer, has seen off an array of challengers for the title of Africa’s biggest.
Built in just two years and launched in 2015, the Tarfaya complex stretches more than 100 square km across the Saharan desert, its 131 wind turbines grinding out enough electricity to power a city the size of Marrakech every day.
Continue reading...Natural flood protection defends homes against Storm Angus
Success of natural measures in Bossington coincided with revelation that such schemes receive no government funding
Natural flood defences, such as allowing trees to fall into rivers, have protected homes in Somerset from the torrential rain brought by Storm Angus. The success came as it was revealed that natural ways of cutting flood risk have no current government funding, despite ministers repeatedly backing the idea.
Heavy rains saw the rivers above the village of Bossington rise rapidly on Monday, but the 100 homes placed at risk avoided flooding. The catchments of the rivers, all part of the National Trust’s Holnicote estate, had natural flood prevention measures put in place in 2013.
Continue reading...Storm Angus floodwater inundates homes in Manchester – video report
Houses in Stalybridge, Greater Manchester, are submerged after severe floods caused by Storm Angus on Monday. Torrential rainfall meant residents had to be evacuated from their homes. 75 flood warnings remain in place across the country on Tuesday
Continue reading...'Extraordinarily hot' Arctic temperatures alarm scientists
Danish and US researchers say warmer air and sea surface could lead to record lows of sea ice at north pole next year
The Arctic is experiencing extraordinarily hot sea surface and air temperatures, which are stopping ice forming and could lead to record lows of sea ice at the north pole next year, according to scientists.
Danish and US researchers monitoring satellites and Arctic weather stations are surprised and alarmed by air temperatures peaking at what they say is an unheard-of 20C higher than normal for the time of year. In addition, sea temperatures averaging nearly 4C higher than usual in October and November.
Continue reading...NHS using Google technology to treat patients
Hello, is this planet Earth? by Tim Peake - in pictures
Based on over 150 photographs taken by British astronaut Tim Peake, the book documents his six months on the International Space Station
Continue reading...Number of plastic bags found on UK beaches falls by nearly half
Conservationists say introduction of 5p levy on single-use carrier bags was instrumental in the reduction
The number of plastic carrier bags found on UK beaches has dropped by almost half, according to conservationists.
The Marine Conservation Society said the introduction of a 5p levy on single-use plastic bags in England, Scotland, Wales and Northern Ireland over the past five years was instrumental in the reduction.
Why China and Europe should form the world's most powerful 'climate bloc'
It seems almost certain that US President-elect Donald Trump will walk away from the Paris climate agreement next year. In the absence of US leadership, the question is: who will step up?
Sadly this is not a new question, and history offers some important lessons. In 2001 the world faced a similar dilemma. After former vice-president Al Gore lost the 2000 election to George W. Bush, the newly inaugurated president walked away from the Kyoto Protocol, the previous global pact to reduce greenhouse gas emissions.
That sent shockwaves around the world, and left nations facing a choice about what to do in the United States’ absence – something they may face again next year. The choice was made more difficult because the US withdrawal made it less likely that the Kyoto Protocol would ever come into force as a legally binding agreement.
However, Europe quickly picked up the baton. Faced with a US president who had abdicated all responsibility to lead or even participate in the global emissions-reduction effort, the European Union led a remarkable diplomatic bid to save Kyoto.
To the surprise of many people, especially in the United States, this diplomatic push brought enough countries on board to save the Kyoto Protocol, which came into force in 2005 following Russia’s ratification.
What will happen this time?While the withdrawal of the United States slowed international efforts back then, as it doubtless will now, this time around the world is in a better position to respond.
First, the Paris agreement has already come into force and global ambition is arguably stronger today than it was in 2001. Whereas the Kyoto Protocol took almost a decade to come into force, the Paris Agreement has taken less than a year. And importantly, whereas countries with emerging economies shied away from any commitment to limit their greenhouse gas emissions under the Kyoto Protocol, this is not so today. Under the Paris deal, both developed and developing countries have pledged to rein in their emissions.
Second, should Europe decide to take on a leadership role as it did in 2001, the rise of China offers a new and potentially powerful partner. China is now the world’s number-one energy consumer and greenhouse emitter. But it has also been one of the most active proponents of climate action.
Under the Paris agreement China has already agreed to cap its emissions and is actively taking steps to reduce its reliance on fossil fuels, especially coal. Recent data indicate that China’s coal consumption peaked in 2014 and is now set to decline.
Filling the voidIf Europe and China together decide to fill the vacuum left by the United States, they could form a powerful bloc to lead global efforts against climate change. Leaders in Europe have already hinted at retaliation should the United States withdraw from the Paris Agreement, with former French presidential candidate Nicolas Sarkozy suggesting a carbon tax on US imports. Should China follow the same path, together they would represent the largest import market in the world, giving them a very large stick to wave at America.
An EU-China bloc could also help to ensure that there is less potential for other nations, including Australia, to follow the United States down the do-nothing path.
That said, while the world’s politicians may be in a better position than in 2001 to deal with the fallout from another recalcitrant American administration, the world’s climate is not. The growth in fossil fuel emissions has been slowed but not yet reversed, and global temperatures continue to climb. The effects are evident around the world, not least in this year’s devastating bleaching of the Great Barrier Reef.
We should expect that President-elect Trump will withdraw from the Paris Agreement. Even if he changes his mind (which he has done on plenty of other issues), there are many in the Republican Party who will hold him to his word.
The climate isn’t waiting to see what a President Trump does, and neither should the world. Should China and Europe decide to lead, many nations will follow, and one day soon so too will the United States.
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Christian Downie ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son poste universitaire.