Our water sources: Groundwater replenishment (video transcript)

With fresh water thinking, we are replenishing groundwater. This is a transcript of our animated video, 'Our water sources: Groundwater replenishment' which explains how this innovative process treats wastewater to drinking water standards and recharges it into existing groundwater supplies.

[Background music]

[Voiceover]: Fresh Water Thinking is replenishing our groundwater.

With Fresh Water Thinking, we’re diversifying our water sources and focusing on those that are NOT climate dependant.

About 40% of Perth’s water comes from our groundwater and groundwater replenishment.

Groundwater comes from rain which percolates down through the rocks and soils and into our natural underground aquifers.

An aquifer is an area under the earth’s surface where water is held between the particles of porous rock or soil (sand, silt and clay). We take water from the ground to feed into our water supply.

Our groundwater is a vital resource, especially given our lack of rain, and it’s one we need to manage in a safe and sustainable way.

One way is by using recycled water for groundwater replenishment.

Groundwater replenishment is a process where treated wastewater is further treated, to drinking water standards.

It doesn't rely on rainfall and has the potential to recycle large volumes of water naturally and sustainably. It also uses less energy than desalination, and makes use of existing infrastructure which helps keep costs down.

So how does it work?

First, ultrafiltration separates out any dissolved materials that are larger than 1/300th the width of a human hair.

Next, through a process of reverse osmosis, water molecules pass through tiny pores, 100 times smaller than ultrafiltration, leaving other dissolved materials behind.

And finally, the water is subjected to ultraviolet light to destroy any trace levels of microorganisms that may remain.

This meets strict drinking water guidelines. It’s then recharged into groundwater for our future drinking water supplies.

This is just one way we are working to secure our water supply for the future.

Australia’s first full-scale Groundwater Replenishment Scheme is being built at Beenyup in Craigie, WA, following a successful three year trial, with support from Perth residents, business and government.

This will deliver around 28 billion litres of recycled water each year. That’s enough to supply up to 100,000 Perth households with water in the future.