Blenheim Sewage Treatment Plant Upgrade

Background

The Blenheim Sewage Treatment Plant (BSTP) is located on Hardings Road, approximately 6km southeast of Blenheim. It has been operating for around 50 years. Serving Blenheim, Marlborough Ridge, Renwick, Riverlands and Cloudy Bay Business Park, the plant is operated and regulated by Marlborough District Council, as a unitary authority.

The Project

The BSTP’s current discharge consents allow treated wastewater to be discharged to both the Wairau Estuary and to Council-owned land around the plant. The current consents expire in October 2025 but it’s a lengthy process to prepare a renewal application, so Council has started work and engaged Beca Ltd to provide technical support.

Before the renewal application can be lodged, a wide range of technical assessments need to be undertaken to understand how the BSTP is performing at different times of the year, its resilience, and the quality of the treated wastewater that is released into the environment.

As part of the investigation into alternative options the project team is looking into the potential to irrigate nearby properties with treated wastewater, as well as considering different climate change scenarios.

Mana Whenua

Located near to the plant, Te Pokohiwi-o-Kupe/Wairau Bar holds national significance. Settled by Polynesian voyagers around 1300AD, the artifacts found here point to it being one of Aotearoa New Zealand's earliest known settlement sites.

Council has partnered with mana whenua and established a Project Working Group, so that aspirations to protect this very significant area, and reduce the impact of the BSTP on the awa, moana, mahinga kai and whakapapa, can be fully considered.

Consultation

We’ll be speaking with stakeholders and the community while we assess various options for the plant. Feedback we receive will help to shape the final renewal application, which must be lodged by April 2025.

You can receive updates on the project, and find out about opportunities to provide feedback, by visiting the Marlborough District Council news page, via our social media channels, and in our weekly e-newsletter, Marlborough Matters (subscribe here).

You can also contact the project team by emailing mdc@marlborough.govt.nz.

Looking ahead

The BSTP is currently operating in line with its consent requirements, but we need to plan how we deal with our wastewater in the long-term. Located in a low-lying marshland, adjacent to a series of tidal channels, in future the BSTP ponds are likely to be vulnerable to sea water ingress, subsidence, and rising sea levels.

As part of this project, we’ll be considering how we can achieve better cultural and environmental outcomes in the long-term for this culturally significant area.

Further reading

Documentation from previous consent applications is available to view at Council's Blenheim and Picton Customer Service Centres and the Marlborough District Library in Blenheim.