Due to a lack of an alternative viable water supply, a small seawater desalination plant was constructed at Penneshaw on Kangaroo Island in 1999.
Seawater is drawn into the plant through an intake pipe and pre-screened. UV disinfection is used to minimise biological growth and filters remove most of the particulate matter. The filtered seawater is forced under high pressure through reverse osmosis membranes that allow fresh water to pass through, with very little salt. The desalinated water is re-mineralised with carbon dioxide (CO2) and marble chips to reduce its corrosive properties and improve taste prior to chlorine disinfection and distribution to customers.
The plant is capable of producing 400kL of drinking water per day.