Martinborough Wastewater Treatment Plant Connections

The issue

Applications for new wastewater connections in Martinborough are being put on pause in Martinborough for the time being because the town’s wastewater plant has failed to meet performance and compliance standards. This is effective immediately.

The plant has also reached its design capacity as population growth and annual connections have far exceeded expectations.

Significant performance and compliance issues resulted in Greater Wellington Regional Council (Greater Wellington) issuing an Abatement Notice for the plant in August 2022. The public health risk from previous discharges to the river is very low and independent specialists engaged by Greater Wellington assessed the environmental risks as negligible.

An abatement notice means the Council is required to act to remedy the identified issues and return the plant to compliance by a certain date and remain in compliance thereafter.

In addition, specialist advice from Council’s water services provider, Wellington Water Limited (WWL), is that additional connections would further compromise the plant’s performance, increasing the risk to the environment, public health and safety. There is also the possibility of more severe enforcement action from Greater Wellington.

This means that the Council is obliged to pause applications for new connections to the Martinborough Wastewater Treatment Plant (MWWTP) effective immediately.

Context

South Wairarapa District Council (asset owner), and our water services operator Wellington Water (asset manager), received an Abatement Notice from Greater Wellington Regional Council (our regulator) for the Martinborough Wastewater Treatment Plant in August 2022. Greater Wellington issued this due to the frequency of non-compliance discharges from the plant to land and water. Council has been instructed by Greater Wellington through the Abatement Notice to cease and be prohibited from commencing all unauthorised discharges from the MWWTP by 15 August 2023 and continue to comply thereafter.

It is worth noting that the public health risk from previous discharges is very low and independent specialists engaged by Greater Wellington assessed the environmental risks as negligible.

WWL, alongside South Wairarapa District Council, are urgently working on a delivery plan to bring the plant back to full compliance as soon as possible, while keeping Greater Wellington updated on progress. Greater Wellington have indicated that further enforcement action remains a possibility if the MWWTP is not operating within its consent conditions.

The plant requires significant investment to resolve the current consent non-compliances and Council is considering all options for this.

Why has this happened?

The MWWTP has been in operation since the 1970’s. The plant has not had the levels of investment needed over its lifetime to maintain its treatment capacity and operational resiliency. The MWWTP requires new pumps, Ultraviolet (UV) systems, screening and treatment systems, among other things. We have also seen higher than expected growth, both in terms of population and new service connections, since the resource consent was renewed in 2016. This has put extra pressure on the plant, pushing it beyond its capacity limits.

In addition, we have the impact of ageing infrastructure across the whole water network. A key issue is Inflow and Infiltration. This occurs when groundwater and stormwater find its way into the wastewater pipes, often due to leaky pipes underground or cross-connections. This increases the volume of water entering the treatment plant, particularly during periods of high rainfall, again pushing the treatment plant beyond its operational capacity.

What are we doing about it?

Council has prepared a Compliance Delivery Plan that sets out how Council plans to address the issues with the MWWTP. A compliance delivery plan is expected to be submitted to Greater Wellington by the end of May 2023 and, assuming it is accepted by them, funding will be secured, and work will begin.

The draft wastewater compliance plan includes a range of operational upgrades and improvements, which are still being finalised. Our estimate is that this will take up to two years and then will be followed by a second stage of work to increase capacity which will take several years to deliver. Growth studies to support the second stage of work will be carried out simultaneously with the compliance work over the next two years to fully inform design.

Funding for both components of the staged plan is not yet confirmed. Some initial funding to start work is included in our proposed 2023/24 Annual Plan, however, significant additional funding from either Council’s 2024-34 Long-term Plan (LTP) or via the new Entity post-Water Reform will be required.

Funding for the second stage, removing capacity constraints, will go through the appropriate consultation and approval processes for the 2024-34 LTP.

We will keep the community updated on key milestones as we and Wellington Water work together towards making the plant fully compliant.

What does this mean for local community and businesses?

This means that the Council is obliged to pause applications for new connections to the MWWTP effective immediately.

South Wairarapa District Council appreciates the impact this decision will have on developers and people seeking to build new homes in the region. We regret having to make this decision which we know will temporarily slow growth in the region. We will pause new connections for only as long as needed.

Council has already started working with customers who have a connection request in train to clarify their status. All permits, resource management and building consents that have been received and approved by Council will be honoured and a connection to the wastewater network made.

Documents

Martinborough Wastewater Treatment Plant Overflow Incident Investigation and Report – January 2020
Martinborough WWTP Abatement Notice – 15 August 2022
Memo – Martinborough WWTP Proposed Corrective Action Plan – 30 November 2022
SWDC Letter – Martinborough WWTP Abatement Notice Response – 1 December 2022
Martinborough WWTP Assessment of Effects During Remedial Works Project – 13 March 2023
Memo – Martinborough WWTP Capacity – 21 April 2023

FAQs