Tahuna Ocean Outfall & Treatment Plant

Dunedin

After careful analysis of a range of options, a preferred $72 million upgrade proposal was submitted for resource consent in September 2002.  The Minister of Conservation signed off on consent in early 2005.  Octa are now project managing a two stage project as under:

STAGE ONE
The strategy for Stage One developed by Octa was to divide the project into three separate contracts – ocean outfall, pumping station and correction to existing wastewater treatment plant and improved odour control.  This approval allowed tailoring selection of contractors with the appropriate skills for each element.

• A new outfall, running from the Tahuna Wastewater Treatment Plant, under John Wilson Memorial Drive (0.4km) and 1.1km offshore into the Pacific Ocean. ($25 million contract awarded in April 2006, with completion targeted for September 2007. April 2008 is the date that the current Lawyers Head resource consent expires)
• A new pumping station, Papatuanuku Junction Chamber at Tahuna
• An upgraded chlorination disinfection facility
• Improved Odour Control

The New Pumping Station is a separate contract as is Odour Control.  Upgrading chlorination will also be a separate contract to commence after monitoring confirms the specific requirement from operational experience.

STAGE TWO
Secondary treatment, to produce effluent that can be treated by UV disinfection. This is planned to be completed by September 2011 and includes upgrading of the sludge incineration operation, including possibly power generation from waste heat.