WASTEWATER OVERFLOW - Impacting Hutt River downstream of Silverstream, Petone Beach, and Eastbourne beaches
WASTEWATER OVERFLOW - Impacting Hutt River downstream of Silverstream, Petone Beach, and Eastbourne beaches

Our crews have stopped the overflow as of 12:30pm, 6 August, and are now working on the full repair.

Residents are asked to not swim in, fish, or collect kaimoana from the following areas until further notice:

- Hutt River/Te Awa Kairangi downstream of Silverstream, including the river mouth in Petone

- Petone beach

- Eastbourne beaches

While the wastewater overflow has been stopped, untreated wastewater was entering Hutt River/Te Awa Kairangi. This means that these areas are unsuitable for the public to swim, fish and collect food from. Water quality testing has begun and will continue for at least 72 hours from 12pm, 6 August, or until results return clear. 
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Your Water / The Network / Wastewater / Wastewater treatment plants / Greytown Wastewater Treatment

Greytown Wastewater Treatment

At the Greytown Wastewater Treatment plant, sewage flows through an aerated facultative pond, a maturation pond and ultraviolet treatment. Discharge of the treated effluent is managed to either an adjacent block of land by irrigation or to the Papawhai Stream, 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 where there is a soil moisture deficit that is greater than the depth of discharged wastewater.
  • to discharge treated wastewater to the Papawai Stream at an annual average daily flow of up to 750 cubic meters per day and at a maximum daily rate of up to 1,500 cubic meters per day.
  • to discharge treated wastewater to land via seepage from the oxidation ponds
  • to discharge  contaminants and odours from the oxidation ponds within the boundary
  • to discharge contaminants and odours from irrigation of treated wastewater to land within the boundary.

Resource consents

WAR080254 Greytown WWTP Consent Conditions

Plant performance

Current Status: Non-compliant

Period: May 2025

 

Commentary:​

In 2023, Greater Wellington Regional Council issued letters requesting explanations of non-compliance. Wellington Water is implementing the required corrective actions where possible within the plant and resource constraints.

Major investment is required, and current approved funding levels do not meet this requirement.

A projectis currently underway to developa second stage of land irrigation (excluding growth). The plantis alreadyoperating beyond its design loading capacityand so new connections have been paused.

The degree of desludging that will be achieved at Greytown is not yet determined. Further funding may be required to complete. The earthworks consent for the desludging activity at Greytown has been approved by GWRC.

Items of significance:

GWRC is currently investigating recent riparian work on the Papawai Stream to confirm it meets their requirements
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.

Irrigation was paused due to the leaseholder organising a contractor to level and reseed the land. Significant irrigator track reconstruction is required, and pasture established before irrigation can recommence.

A total of 68500m3 was irrigated to land this 2024-25 season.