TURTLES may have eaten their first trial, but a second trial using mattresses to purify waste water is proving a success for Queensland Urban Utilities.
The state first trial is being conducted at the Forest Hill Sewage Plant.
The project involves growing wetlands on specially engineered plastic mattresses, which are then floated on the lagoons at the plant.
Queensland Urban Utilities spokesperson Michelle Cull said it was a natural, cost effective and energy efficient solution to purifying the water.
"The roots of the plants dangle beneath the mattress drawing out nutrients such as carbon, nitrogen and phosphorus," Ms Cull said.
Brisbane short-necked turtles ate the roots of the plants in the first trial, which was started in spring last year.
The second time around, mesh covered the plants and has so far been a success since it was started in March.
QUU operations spokesperson Mike Oakey said after the mattress process and the final filtering stage, neighbouring farms were able to use the water for irrigation.
Ms Cull said the trial would run until the end of the year and if successful, it could be rolled out at similar regional plants.
"So far it seems to be working - the plants are thriving and early water quality test results are promising," she said.
The Forest Hill Sewage Plant currently takes in 113,000 litres of waste water a day which adds up to 41 megalitres a year, equivalent to 17 Olympic swimming pools.
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