Reverse osmosis (R/O) desalination units supplement rainwater harvesting on Funafuti. The 65 m3 desalination plant operates at a real production level of around 40 m3 per day. R/O water is only intended to be produced when storage falls below 30%, however demand to replenish household storage supplies with tanker-delivered water means that the R/O desalination units are continually operating. Water is delivered at a cost of A$3.50 per m3. Cost of production and delivery has been estimated at A$6 per m3, with the difference subsidised by the government.