Groundwater Replenishment Schemes

Ever wondered how we, on the so-called 'blue planet', where more than 70% of the planet is made up of water, could ever be lacking in the blue stuff to actually drink? Of all the water on the Earth, almost 97.5% is contained in seas and oceans, which is undrinkable without treatment. The remaining water is freshwater but over half of that water is frozen. When you take into account water vapour and any other sources, it's actually around 1% of all the water on Earth is drinkable. It's no wonder why we are looking for alternative ways of making water drinkable. Perth in Western Australia is the country's driest major city. Between 1990-1999 the annual rainfall in Western Australia was 766mm, this number has dropped to 656mm since 2009. The climate in Western Australia has changed very quickly. Sue Murphy is the chief executive of the Western Australia Water Corporation. Speaking of the climate in Perth, she said the following:
"Western Australia has seen climate change happen faster and earlier than almost anywhere else on the planet. In the last 15 years the water from rain into our dams has dropped to one-sixth of what it used to be before that," 
Perth is part of the Integrated Water Supply Scheme (IWSS) which supplies 279 billion litres to 1.5 million people. Two large desalination plants are used for turning water from the Indian Ocean, into potable drinking water. The process of desalination is expensive and requires a lot of energy so household bills in the area have doubled over recent years. It is hoped that the answer has been found with the introduction of a Groundwater Replenishment Scheme. This is an innovative idea where treated waste-water is further treated to drinking water standards. The treated water is then recharged into groundwater supplies. Perth's largest source of ground water is the Gnangara system.  The Australian Water Corporation have been conducting various tests over the last few years and have come to the conclusion that this was a highly viable option to boost much needed drinking water supplies in Western Australia. The Groundwater Replenishment Scheme will be rolled out in three stages. The first stage will be be the extend the trial plant and enable it to produce 7 billion litres of recycled water. The second stage will be to begin recharging water in June 2018, when 28 billion litres of recycled water will be produced. Recharging the name given to the process where water moves downwards from surface to groundwater. The third stage will be to begin recharging in June 2022. This third cycle of recharging will produce around 28 billion litres of recycled water. In Perth groundwater is stored in three layers of aquifers. The superficial aquifer is the most shallow aquifer, sometimes in the form of wetland or lakes. The Confined Leederville aquifer is mostly just below the superficial aquifer. Thirdly is the Yarragadee aquifer, the deepest, most vast aquifer with limited connection to the surface. Perth's groundwater system The Groundwater Replenishment Scheme would see less water used from the superficial aquifer, meaning that the impact on the environment is minimal. The Leederville aquifer would be replenished and more water could then be taken from the deepest aquifer. By 2022 it is hoped that around half of Perth's water supply will come from deep groundwater sources. What do you think of groundwater replenishment? Is this something you think could be adopted in other areas?
June 24, 2014
In: Industry News
Tags: Australia, Perth, Groundwater Replenishment, Desalination, Aquifer, Recycle, Recharge, Blue Planet, Earth, Drinking Water


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