Groundwater replenishment

Groundwater replenishment is an innovative concept where treated wastewater is further treated to drinking water standards and recharged into groundwater supplies. The water is then stored and taken out some time later for further treatment and supply to a drinking water system.

We completed a three-year Groundwater Replenishment Trial on 31 December 2012.

Together with the trial regulators – Department of Health, Department of Water, and Department Environment and Conservation – we are now completing an assessment of the trial for consideration by the State Government. We expect this assessment to be finalised by May 2013.

For now, we continue to operate the Advanced Water Recycling Plant and monitor the quality of recycled water to ensure it meets the required standards.

As at 20 May 2013, 2.915 billion litres of recycled water has been recharged.

Why groundwater replenishment?
Why groundwater replenishment?

As WA continues to experience a drying climate and an increasing population, demands on our water supplies are greater than ever. Groundwater replenishment could help Perth by:
- Reducing our dependence on rainfall as a source of water;
- Ensuring ‘climate resilience’ by recycling water on a large scale; and
- Potentially providing up to 20 per cent of Perth’s drinking water supplies by 2060 (if expanded to our other major wastewater treatment plants.
Why do a trial?
Why do a trial?

From 2009 to 2012, we trialled groundwater replenishment under local conditions at our Advanced Water Recycling Plant in Craigie to determine if it could be used as a sustainable option to boost drinking water supplies in the future.

The Groundwater Replenishment Trial sought to meet three objectives:
1. prove technical feasibility;
2. establish a framework for policy and regulation;
3. and ensure sufficient community engagement and acceptance.
The trial also allowed us to gain knowledge about the effect groundwater replenishment has on the groundwater environment.

At the end of the trial, more than 62,300 water quality samples had been taken (throughout the treatment process and at the point of recharge), all of which met stringent health and environmental guidelines.

We also engaged the community through tours of the visitor centre, social media, community festivals and online forums.

The final telephone research completed in October 2012 showed that community support for a full-scale scheme was 76 per cent.
How is wastewater treated?
How is the wastewater treated?

Before wastewater reaches the Advanced Water Recycling Plant, it has already undergone rigorous treatment at the Beenyup Wastewater Treatment Plant to remove chemicals and micro-organisms such as bacteria, nutrients, detergents, oils, pesticides and heavy metals.

At the Advanced Water Recycling Plant it undergoes further treatment processes which include ultrafiltration, reverse osmosis and ultraviolet disinfection. This removes chemicals and micro-organisms to meet World Health Organisation standards and Australian guidelines for drinking water.
How is water quality monitored?
How is water quality monitored?

There are several water quality checkpoints (known as critical control points) throughout the treatment process to ensure each stage of the plant is working at optimum levels.

If water does not meet the required standard when it reaches a check point, it triggers an alert for action to be taken. For example, we may need to divert the recycled water back to the Beenyup Wastewater Treatment Plant or temporarily shut down the plant.

For more information view the latest Water Quality Report.