A design and construct contract was awarded to Aquatec Maxcon by TasWater to upgrade the Longford sewerage treatment plant.

The upgrade is expected to significantly improve the quality of effluent discharge and better manage the sewerage smells inflicted upon the town.

TasWater project manager Rennie Brown said it was an exciting time.

A new technology called Nerada is expected to process wastewater products more efficiently compared to conventional methods.

Other benefits include capital cost savings and the improvement of the overall carbon footprint.

"Wastewater at Longford is a mixture of domestic and trade waste and is varied in strength so this technology provides a robust system to respond to the incoming loads," he said.

"Parts of the new plant will be fully enclosed and have a two-stage odour control system incorporated to remove odours before air is extracted.

"This will help us meet our commitment to the community to reduce odours coming from the sewage treatment plant.

"We have made significant improvements recently to reduce sewage odour in the town but it is possible some odour may be noticed at times until the new plant is commissioned."

THE STORY SO FAR

The "Longford pong" was first officially raised at a Northern Midlands Council meeting in March.

Odour was believed to be caused by the meatworks on Tannery Road and the TasWater sewerage treatment plant on Bishopsbourne Road.

The smell became particularly bad in February, with hot weather, a breakdown in the screw press in the rendering plant at JBS, and additional gases produced from fat digestion at the TasWater plant.

"We took a forward-thinking approach on this project by involving contractors early in the process," Mr Brown said.

"This has resulted in an innovative plant design, the first of its kind for Tasmania, and we look forward to working with Aquatec Maxcon to see it completed.

"The innovative process incorporates a granular biological substrate used to remove contaminants, with improved nutrient removal. This allows smaller treatment tanks, is more energy efficient and provides increased flexibility to manage different strengths of wastewater."

The design of the new plant meant it could easily be upgraded to increase capacity if required later down the track, Mr Brown said.

"The plant will have a slightly smaller footprint, so can be built within our existing site, but will allow flexibility for future growth," he said.

Design work is underway, with construction to begin once a sufficient design is complete and all approvals are secured.

Longford residents will be notified prior to any construction taking place.