$320m supports Perth’s rainfall-independent future

Perth's rainfall-independent future has been further secured following the commissioning of a major $320 million expansion of Water Corporation's Groundwater Replenishment Scheme (GRS).

Perth’s rainfall-independent future has been further secured following the commissioning of a major $320 million expansion of Water Corporation‘s Groundwater Replenishment Scheme (GRS).

Perth’s water future has been further secured following the commissioning of a major $320 million expansion of Water Corporation’s Groundwater Replenishment Scheme (GRS), announced today by Water Minister Dave Kelly.

Groundwater replenishment is a sustainable, rainfall-independent water source. Purified recycled water is stored in deep underground aquifers to replenish groundwater supplies naturally.

The first stage of Water Corporation’s GRS was Australia’s first full-scale groundwater replenishment strategy. It had an annual capacity of 14 billion litres per year.

Stage One delivered on the West Australian Government’s vision to utilise this innovative technology to recycle our precious water resources. It has been operating since 2017 – recharging more than 54 billion litres of water.

The second stage of expansion will double the long-term capacity of the scheme, up to 28 billion litres each year. This will be enough water to supply up to 100,000 Perth households.

Groundwater currently provides up to 40 per cent of Perth’s drinking water supplies. It also provides water for industry and horticulture, garden bores, parks and other green spaces.

Developing WA’s rainfall-independent future for decades

However, since 1980, the impacts of climate change and reduced rainfall have seen water tables fall by up to 10 metres in some areas. It represents a 1,000GL loss of aquifer storage, equivalent to 1,000 Optus Stadiums full of water.

The innovative scheme sees highly treated wastewater from the Beenyup Water Resource Recovery Facility purified at the advanced water recycling plant to a level that exceeds drinking water standards.

This purified recycled water is recharged to the Leederville and Yarragadee aquifers on-site at Craigie and, via a 13km pipeline, at additional bores in Neerabup and Wanneroo.

New infrastructure constructed as part of the Stage Two expansion includes:

  • a second, advanced water recycling plant next to the first at Water Corporation’s Beenyup facility in Craigie;
  • four recharge bores and four monitoring bores across two recharge sites in Neerabup and Wanneroo; and
  • a 13km recharge pipeline transfers the purified recycled water from the plant to the new bores.

Construction of the second stage began in late 2017, employing more than 380 local workers. The rainfall-independent future scheme will be fully commissioned following additional testing on the off-site bores.

This innovative water source forms part of Water Corporation’s three-stream approach to develop new water sources, reduce water use and increase water recycling. By 2035, Water Corporation aims to recycle more than a third (35 per cent) of treated wastewater.

The expanded GRS follows the Government’s commitment to building the first two stages of a new desalination plant proposed at Alkimos. The first 50 billion-litre stage is expected to be operational by 2028.

Comments attributed to Water Minister Dave Kelly:

“Due to the impacts of climate change, reduced rainfall and increased abstraction, our groundwater resources are under pressure.

“Water Corporation’s Groundwater Replenishment Scheme is an innovative and sustainable way to recycle large volumes of water.

“By recharging our precious groundwater supplies through the scheme, we can abstract equivalent groundwater in later years. It will add to Perth’s drinking water supply while reducing impacts to the environment and other water users.

“Along with the Government’s commitment to building a renewably-powered desalination plant at Alkimos by 2028, this major $320 million investment will help secure Perth’s water supplies and manage the impacts of climate change.”

Water Corporation groundwater replenishment and rainfall-independent future fact file

  • Groundwater replenishment is when highly treated wastewater undergoes advanced treatment to produce purified water beyond drinking water standards.
  • The water is then stored in deep underground aquifers until it is extracted years later. It will then be treated further, and supplied to Perth’s drinking water system.
  • In the five years since its commissioning in 2017, Stage One of the Groundwater Replenishment Scheme has recharged more than 54 billion litres of recycled water.
  • Stage Two builds on its success by doubling the recharge capacity from 14 billion litres per year to up to 28 billion litres of water into groundwater supplies yearly. This is enough to supply up to 100,000 households.
  • By 2035, Water Corporation’s goal is to recycle more than a third (35%) of wastewater.
  • Water from the full-scale scheme is being recharged via on-site and off-site recharge bores. This comprises both Leederville and Yarragadee bores, with the Leederville bores between 200 and 500 metres deep and the Yarragadee bores between 700 and 1,400 metres deep.
  • Groundwater replenishment uses the same reverse osmosis treatment process as seawater desalination. Still, it is much more energy efficient by using around a quarter of the energy. Less pressure is required to remove impurities from the treated wastewater than salt from seawater.
  • This greater efficiency helps Water Corporation’s net zero emissions target across all operations by 2035.
  • Before Stage One, the Groundwater Replenishment Trial ran for three years, from 2010 to 2012. It was the first trial to be conducted in Australia on that scale.
  • The trial plant continued to operate until September 2014. From the start of the trial until its closure in 2014, the plant recharged nearly five billion litres of recycled water into groundwater supplies.
  • Stringent systems, processes and regulations ensure groundwater replenishment does not present any public health or environmental risks.
  • The purified water from the advanced water recycling plant is so pure that minerals and chlorine would need to be added to supply it as drinking water.
  • Other parts of the world, such as Orange County in the US and Singapore, have been successfully recycling water for drinking for many years.

Related Articles:

Send this to a friend