Groundwater varies in its concentration of dissolved salts, and in many cases, the concentration is so high that the water is unsuitable for drinking without treatment.
Australia relies heavily on groundwater sources, with around four million people dependent partially or totally on groundwater for domestic water supply.
A report by Australia’s National Water Commission (Brackish groundwater: a viable community water supply option?) investigated the feasibility of treating brackish groundwater as a community water supply option in regional and remote communities in Australia.
It provides water supply authorities with a practical way of determining what needs to be taken into consideration for a new water supply investment in groundwater.
Water authorities considering brackish groundwater desalination as a water supply option can learn from towns and communities that already own and operate desalination plants.
This report investigates six such locations around Australia and presents case studies on each.
The key findings of this report indicate:
- Brackish water desalination using reverse osmosis membranes has been successfully employed since the 1980’s to produce drinking water in a number of inland towns and communities where other water supply options have been limited.
- Investment in detailed preliminary investigations was a key factor in the success and viability of the long-term operation of the case study sites.
- Capital and operating costs for desalination are location-specific and can vary greatly between installations.
- Brine disposal management poses significant environmental and cost challenges for water managers, with evaporation ponds requiring up to 50 per cent of the capital costs.
- Beneficial reuse of brine for agricultural purposes is not common in Australia; however this report identifies some salt tolerant crop varieties which could be considered for Australian applications.
The overall feasibility of new groundwater supplies is dependent on a number of considerations, particularly geographic location and raw water quality. Subject to these considerations, brackish groundwater desalination can be considered a viable community water supply option in some areas.