Perth’s landmark Groundwater Replenishment Scheme has reached a major milestone with 100GL of purified recycled water – equivalent to 100 Optus Stadiums – recharged into climate-impacted groundwater aquifers.
Commissioned by Water Corporation in 2017, the scheme takes treated wastewater from the Beenyup Water Resource Recovery Facility in Craigie and purifies it to drinking water standards at the adjacent Advanced Water Recycling Plant.
Purified water is then recharged deep into underground aquifers where it is further filtered and used to support the sustainability of vital groundwater resources.
Groundwater currently makes up around 40 per cent of Perth’s drinking water, and supplies much of the water used by industry, horticulture, and to irrigate parks, ovals and public green spaces.
However, since 1980, the impact of climate change on rainfall has seen an alarming drop in groundwater levels.
Water Corporation Head of Treatment and Resource Recovery, Rino Trolio, emphasised the important role of groundwater replenishment in meeting the challenges posed by climate change.
“The impact of climate change on Perth’s water resources is clear – since 1980, rainfall has declined by 20 per cent and groundwater levels have fallen by as much as 10m in some areas,” Mr Trolio said.
“We’ve had to do things differently in Western Australia and turn to innovative projects such as the Groundwater Replenishment Scheme that reduce our reliance on rainfall.
“Replenishing groundwater through the scheme allows us to abstract an equivalent volume of groundwater from elsewhere, which helps ensure the groundwater we use as drinking water is sourced sustainably.
“[Reaching] 100GL is a really significant milestone, and highlights to other Australian water utilities how beneficial such a scheme can be in a drying climate.”
The scheme, which has the capacity to recharge 28GL of purified water each year, was the first of its kind in Australia and one of only three in the world when first commissioned.
In addition to water recycling, investment in climate-resilient water sources and water efficiency is fundamental to future water security across Western Australia.
Groundwater replenishment is a process where 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, treated further and supplied to Perth’s drinking water system.
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 for it to be supplied as drinking water.
Groundwater replenishment uses the same reverse osmosis treatment process as seawater desalination but is much more energy efficient – using around a quarter of the energy – as far less pressure is required to remove impurities from the treated wastewater than salt from seawater.
This greater efficiency helps Water Corporation’s target of net zero emissions across all operations by 2035.
The recharge capacity for Water Corporation’s scheme was doubled in 2022 from 14GL per year up to 28GL of water into groundwater supplies each year – enough to supply up to 100,000 households.
By 2035, Water Corporation’s overall goal is to recycle more than a third (35 per cent) of wastewater.
For more information about the Water Corporation’s Groundwater Replenishment Scheme, visit www.watercorporation.com.au/GWR.
