The New Picton Harbour Wastewater Outfall - A Clear and Effective Solution

The outfall pipeline from the Picton Sewage Treatment Plant, to the discharge at Kaipupu Point, was under capacity and its condition was deteriorating. The above-ground portion pipeline was considered to be an “eyesore”.

Marlborough District Council and CH2MBeca (Beca), together with a Consultative Working Group (CWG), began assessing wastewater disposal options, including irrigation as well as new outfall sites in Picton Harbour and Shakespeare Bay.

An evaluation of the environmental, public health, engineering and economic implications of these options was undertaken and discussed with the CWG and other community stakeholders. A mid-harbour outfall was proposed as an environmentally sustainable and cost-effective solution.

The CWG and community were presented with the concept of a well-designed outfall, where neither bathing nor shellfish gathering would be at risk. The outcome was that Council obtained consents with no appeals and a 35 year consent term. The paper highlights the desirability, when consenting potentially contentious projects, of combining appropriately robust technical investigations with early and meaningful communication with key stakeholders. The new Picton outfall is a cost-effective and sustainable solution and a key first stage in a wider strategy to improve the capacity of the Picton/Waikawa Sewerage System.