CONSTRUCTION of the wastewater treatment plant at Cedar Grove has reached the halfway mark.
When complete by mid-next year, the plant will service the Greater Flagstone Priority Development Area, expected to be home to 120,000 people by 2050.
The infrastructure is being built in two sections with the first line between Greenbank and Flagstone to be 10km long.
A second pipeline connecting Flagstone to Cedar Grove will be nine kilometres in length.
Four pump stations will be built along the route.
Construction work has included a combination of open trench, tunnel boring and horizontal directional drilling methods.
A Logan City Council spokesperson said the wastewater facility would operate according to strict environmental standards and achieve a net environmental benefit for the local catchment.
"Wastewater will undergo a biological treatment process before being released to the river via man-made wetlands, where native plants will polish the treated water to a very high standard," the spokesperson said.
"It will be one of the best-performing wastewater treatment plants in Australia and will deliver environmental benefits to the river and its catchment."
Former Logan City councillors voted to approve a sewage treatment plant at Chambers Flat in a split decision days before their dismissal earlier this year.
The council is yet to set a timeline for construction of the plant at Pleasant View Road which will service the growing suburbs of Yarrabilba, Logan Reserve and Park Ridge.
Residents near the approved site have submitted a petition to Logan City Council opposing the decision.
