Martinborough Wastewater Treatment Plant
At the Martinborough Wastewater Treatment plant, sewage flows through an aerated facultative pond, a series of maturation ponds and ultraviolet treatment. Discharge of the treated effluent is managed to either an adjacent block of land by irrigation or to the Ruamahanga River depending on the season, river levels and conditions of the Resource Consents.
The plant was granted new consents on 11 February 2016. These consents will continue for 35 years (expire 11 February 2051).
In general, the consents allow SWDC:
- to discharge treated wastewater to land via an irrigation system at a flow rate of 795m3/day (Stage 1B) and 4300m3/d (Stages 2A and 2B)
- to discharge treated wastewater to the Ruamahanga River at an annual average daily flow of up to 650 cubic meters per day and at a maximum daily rate of up to 4,300 cubic meters per day
- to discharge treated wastewater to land via seepage from the oxidation ponds
- to discharge odours from the oxidation ponds within the boundary
- to discharge odours and other contaminants from irrigation of treated wastewater to land within the boundary.
Resource Consents
Plant Perfomance
Current Status: Non-compliant
Period: February 2025
Commentary:
In June 2024, a new 'To Do Abatement Notice' was issued for Martinborough, with a deadline of May 2025 to complete desludging. This superseded the May 2024 and August 2023 'To Do Abatement Notices', which in turn replaced the Abatement Notice issued in 2022, although the WWTP still remains non-compliant.
Wellington Water and South Wairarapa District Council are working together to address the items raised in the new Notice, as part of the compliance upgrade project underway.
Tendering for the desludging works has been completed and is expected to commence in April.
Major investment is required, and current approved funding levels do not meet current operational requirements.
Items of significance:
GWRC's Annual Compliance Assessment Report was received in November 2024. The overall compliance summary for the WWTP was rated as "Poor"
Current plant design is insufficient to avoid non-compliance. Effluent discharge rate to land continues to exceed current consent limits. Effluent volume and quality discharged to river continues to exceed the annual consent limits.
New connections have been paused while a Growth-Capacity study is undertaken to determine how to ensure the WWTP can operate compliantly with new connections.
Work is progressing well on the basis of design for the Stage 2A irrigation area as well as the Growth-Capacity Study. These two pieces of work are being developed together to ensure a cohesive solution is defined for the site.