Water plants not efficient
WATER treatment plants supplying Douglas are not running efficiently and nothing will be improved, pending the incoming Douglas Shire Council.
A quarterly report presented to Cairns Regional Council recently showed water treatment plants in Mossman, Daintree and Whyanbeel are not utilising water going through the plant as efficiently as plants supplying mains water to Cairns.
Mossman’s plant is at 85 per cent, Whyanbeel at 75 per cent and Daintree is at 65 per cent, with the report stating: ‘‘Quantity of water is required for the maintenance of the membrane filters impacts on the efficiency.’’
CRC manager of Water and Waste Paul Utting said they were measured by how much water is lost to backwashing versus how much is coming into the plant, which is different to what goes through into consumption.
‘‘The target was 97 per cent based on the performance of the mains supply plant to Cairns, which is a relatively traditional sand filter plants, but the three plants up in Douglas are membrane plants, which is a different technology,’’ he said.
‘‘Essentially the membrane is like a porous straw - water drawn through porous surfaces leaves the bad stuff outside and good stuff on the inside.
‘‘One of the limitations of that technology is the back washing process happens differently and doesn’t achieve the same sort of efficiency as the traditional plant, but does so effectively and cheaply.’’
Mr Utting said to achieve the same efficiency as Cairns the plants would require significant changes, which is associated with that capital expenditure.
‘‘That doesn’t deliver any benefit other than efficiency and is a decision best left to the new Douglas council,’’ Mr Utting said.
‘‘It’s not as if it’s hugely inefficient or expensive and the new council can decide to leave it as it is, which is a perfectly acceptable solution, or lift efficiency and get some benefit out of it.
‘‘Key are is that your existing water source will supply more customers, and considering the concern over water levels and Rex Creek, if you are able to produce more water through the plant it creates more capacity.’’
Mr Utting said council was not concerned at the levels and that in view of the ‘‘considerable investment, the decision is best made by the new council’’.