SA Water waste water treatment plant at Brinkley, serving Murray Bridge, under construction

Construction is due to start on Thursday on a new, $52 million waste water treatment plant at Brinkley.

The plant, to be owned by SA Water and built by engineering contractor John Holland, will treat all of Murray Bridge's sewage once it is complete, replacing a smaller, outdated plant near the Long Island marina.

Mark Gobby, SA Water's operations and delivery general manager, said the new plant had been designed to meet Murray Bridge's needs until at least 2060.

Benefits of the move would include the opportunity to develop SA Water's riverfront land, which would no longer smell, and a higher quality of treated effluent.

John Holland project manager Wes Johnston said his company would prioritise local suppliers and contractors during construction.

"Everyone involved has been local: plumbers, electricians, contractors; we've got the Ngarrindjeri here, working on rooves; even all our office furniture we've got from Office National in Murray Bridge," he said.

"Our commitment is to go through local contractors as much as we can on this project."

Local school and community groups would also be encouraged to visit the construction site, and would be able to look on from a safe viewing area without going through the rigmorole of waiver forms, vests or safety goggles.

He pointed to different parts of the site in turn, marked with orange cones: there would be two covered tanks, there the plant itself, there an administration building and pumping station, there a drop-off point for septic trucks, and there a 150-kilowatt solar plant which would power the facility.

Eighteen kilometres of pipes and a new pumping station will connect the plant to Murray Bridge's sewers and to the army range on the east side where all treated effluent is disposed of.

The new plant is due to be finished and commissioned in 18 months' time, and the the old plant decommissioned around the same time – in 2020.

John Holland will continue to operate the new facility for two years after that, proving that it works, before handing it over to SA Water permanently at the end of 2022.

The move has been in the works for eight years.

SA Water project manager Chas Allen said the new plant would eliminate many of the jobs which were not very pleasant for staff at the current site.

"We look forward to that day," he said.

About 50 workers, contractors, executives and Murray Bridge Mayor Brenton Lewis attended a ceremony marking the milestone at the facility's future site, off Pfeiffer Road, on Monday.