Downer NZ

CATEGORY 3: Projects with a value of between $20 million and $100 million

PROJECT: Shotover Waste Water Treatment Plant Upgrade. CONTRACTOR: Downer NZ

Under pressure

Located on the right bank of the Shotover River Delta, the existing Queenstown Wastewater Treatment Plant was under significant pressure due to the expanding population, booming tourism industry and ever more stringent discharge conditions. Queenstown-Lakes District Council responded to this pressure by embarking on one of its largest and most strategic upgrade projects.

Downer was engaged through an EOI process followed by a short-listed tender to undertake the first stage of the planned three-stage upgrade to the existing facility.

The first stage was the cornerstone in Queenstown-Lakes District Council’s three-stage development plans, involving the design, construction and commissioning upgrade to the existing Shotover wastewater treatment plant and disposal facility, and the subsequent operations and maintenance of the works for a 60-month period.

The design, build and operate contract involved over 100,000 man-hours, and the efforts of more than 160 subcontractors, consultants and suppliers to complete. The project was truly multi-disciplinary encompassing every engineering discipline to deliver a technologically cutting-edge treatment plant for Queenstown-Lakes District Council.

There were a number of challenges including the site’s close vicinity to Queenstown, which meant accommodation was in short supply and there was a risk around the availability of skilled labour and subcontractor procurement.

The location of the project also presented risk with the required continuous supply of concrete for large pours. This was mitigated by making contingency arrangements with other batching plants in the area.

The intersection at site access was a safety issue, with the team witnessing many near misses with vehicles turning right on to the state highway. To mitigate this risk, Downer added a recommendation to the inductions on site, for people to turn left at the intersection using the nearby roundabout instead.

The contract for Project Shotover was awarded to Downer in May 2015. By January 2016, construction was complete and the facility was producing compliant wastewater.

Downer will continue to operate and maintain the facility until 2021. l