Project Gilghi

A breakthrough off-grid water purifying system for use in remote indigenous communities.

More than 40,000 Indigenous Australians in 694 locations nationwide rely on groundwater for water supply and face challenges in accessing clean drinking water that meets the Australian Drinking Water Guidelines.

The community of Gillen Bore in the Northern Territory had access to bore water, with a new bore sunk in 2014 but relied on the continued transport (150km round trip from Alice
Springs) of potable water due to high salinity, hardness and low pH levels in the bore water – a costly and inefficient expense.

Gilghi, which means “water” or “place of water” in the Barkindji Indigenous language, was three years in the making for client Ingkerreke Resource Services and was enabled by a $70,000 Municipal and Essential Services Special Purposes Grant from the Northern Territory Government.

Water treatment is energy intensive and accounts for 13% of Australia’s electricity use. For remote communities with no connection to the main power grid, infrastructure overcapitalisation is unavoidable if wanting to produce a small-scale drinking water treatment plant. Often the only viable solution is relying on alternative water sources, typically expensive transported water.

An innovative solution
Gilghi’s flexible design enables the system to meet larger supply requirements and different treatment challenges without adversely affecting the cost per litre.

Advanced filtration: Source water is stored in an inlet tank before passing through three stages of treatment:

• Media filtration (sand media, carbon and softener)
• Reverse osmosis (RO) unit comprising of cartridge filters, pressure booster pump and RO membranes
• Outlet tank and UV disinfection system

Waste stream processing includes an evaporation pond to treat the brine from the RO process. In arid climates, residual saltwater can be used as a feedstock for succulents and to grow salt-tolerant plants.

Gilghi uses a stand-alone hybrid power supply utilising:

• PV solar used to operate the treatment process and/or charge the backup battery system when required
• Battery storage
• Innovative electrical control system allowing both AC>DC and DC>AC conversions
• Back-up diesel generator

Employing a ‘plug and play’ approach, all components of the plant were prototyped, assembled, connected and tested at Ampcontrol’s Newcastle NSW facility.