How recycled water is used

We produce Rhodes Grass hay at our Broome North Wastewater Treatment Plant as an environmentally friendly means of disposing of recycled water.

About 306 million litres of recycled water is used to irrigate Rhodes Grass each year, which is then processed into hay and sold for stock feed to local cattle stations.

Proceeds made from the sale of the hay is being used to run the West Kimberley Community Grants Scheme. The grants scheme is being delivered by Water Corporation and the Lions Club of Broome to support and empower people and communities in the West Kimberley.

Five community projects that support education, culture, the environment, health and tackling drug and alcohol abuse have been successful in receiving funding in round one of the program.

Recycled water from our Broome North Wastewater Treatment Plant is also being used to establish a native tree seed bank, a joint project with Mamabulanjin Aboriginal Corporation, with the first stage of this innovative project now complete.

The native tree seed bank project provides people with the opportunity to learn to install and operate irrigation systems, operate small machinery, establish native plants through propagation and planting and learn weed management practices.

Over 17 hectares of land near the Broome North Wastewater Treatment Plant will be used to grow native trees to provide seeds for land restoration programs in the area, and to preserve endemic plants that are at risk of becoming endangered.

In WA, all industries (including mining) using more than 20 million litres of water per year are required to undertake a mandatory Water Efficiency Management Plan. These plans consider the potential onsite reuse of water, or use of recycled water from wastewater treatment plants.

Many industries are embarking upon process improvements to reduce the amount of water used and many already recycle water onsite.

The Woodman Point wastewater treatment plant supplies treated wastewater to the Kwinana water recycling plant. Through filtration and reverse osmosis, wastewater is further treated to a quality suitable for use by major Kwinana industrial customers.

Across Western Australia, wastewater treatment plants have long been recognised as secure alternative sources of water.

Ovals, golf courses and open community areas are thriving from this alternative source of water.

Some regional areas have achieved a 100% recycling rate of wastewater through wastewater treatment.

In Perth, the use of recycled water (as opposed to scheme water) from the Subiaco wastewater treatment plant has seen nearly 1.5 million litres of water saved every day. This is achieved through the use of recycled water for onsite treatment processes, landscape irrigation and for irrigation of external parks and gardens.

Recycled water from the plant provides a source of alternative water for irrigating around 20 hectares of the McGillivray Sporting Complex.

Groundwater replenishment is an innovative process that involves treating wastewater to drinking water standards and recharging it into our groundwater supplies.

The water can then be stored in the groundwater and removed some time later for further treatment, ready to supply our drinking water system.

Our Beenyup wastewater treatment plant is the first plant to support groundwater replenishment, with the nearby Advanced Water Recycling Plant in the final stages of commissioning.

This will be Australia’s first full scale groundwater replenishment scheme, and will have the capacity to initially recharge 14 billion litres of water into groundwater supplies, to be expanded to 28 billion litres a year by 2019.

Treated wastewater can be utilised for the irrigation of food crops and non-food crops such as turf and trees.

Agriculture and horticulture

At the Broome North wastewater treatment plant, recycled water is used to irrigate Rhodes grass. The Rhodes is regularly cropped for hay, which is then sold and used to fund a regional grants scheme.

At the same treatment plant and in a collaborative project between Water Corporation and Mamabulanjin Aboriginal Corporation, recycled water is used to grow native trees which provide seeds for land restoration programs in the area.

Woodlots

Around 1,000 hectares of trees are supplied with our treated wastewater for irrigation across the south west of WA. The woodlots are mostly Eucalyptus globulus, commonly known as Tasmanian Bluegums.

We have woodlots at the Albany, Dunsborough, Margaret River, Bridgetown, Manjimup, Walpole, Denmark and Donnybrook wastewater treatment plants.

We also grow Sandalwood on two of our wastewater treatment plant sites located at Toodyay and York.

Our drying climate means there is increasing demand to use treated wastewater to support natural wetlands.

Treated wastewater is used to support natural wetlands by either direct discharge to the wetland or through infiltration to the underlying groundwater which supports the wetland.

The Spectacles

The Spectacles comprise two important wetlands which form part of the Beeliar Regional Park.

Treated wastewater from the Kwinana wastewater treatment plant is infiltrated to the underlying groundwater system. Here it forms a mound to help prevent the westward flow of groundwater and the wetlands from drying as others have in recent decades.

Derby wetland

We constructed a controlled wetland next to the wastewater treatment plant in Derby which uses the treated wastewater. Bird watchers visit the facility which is now an important habitat for migrating birds.

Biosolids and biogas are both renewable resources that we produce from wastewater sludge.

Biosolids

Biosolids are the byproduct from wastewater treatment process that has undergone further treatment to produce a stabilised product suitable for beneficial use. This biosolid is loaded into trucks and transported to sites where it can be used beneficially for certain, agricultural and forestry applications under strict environment and health licence conditions.

Biogas

Biogas is produced through the digestion of wastewater sludge. The biogas has a higher concentration of methane gas, which is used to generate electricity and heat which is then used in wastewater treatment processes. Renewable energy is produced through this process at our Woodman Point wastewater treatment plant.