Wastewater discharge

Molly Callanan-Bartlett from Wellington Water

UPDATE 4 - 11.30AM, 5/2

Staff remain onsite at the impacted areas, distributing fliers and speaking with the local community. This will continue throughout the day.

Crews are working to ascertain the full impact of the flooding on the plant’s equipment and operations. This assessment will take some time, and we expect that this will be an extended outage at the plant.

We are undertaking work to check the condition of the long outfall pipe by sending cameras down the beginning of the pipe and having divers check the end of the long outfall underwater.

Shoreline inspections and clean-up of debris on the coastline around the short outfall continue three times daily, with a focus on completing these at low tide.

All untreated wastewater is still being discharged through the short outfall pipe. We are working to divert as much as possible to the long outfall, as quickly as possible, and to put screening in place to remove items like sanitary pads from the wastewater being discharged. We do not have a timeframe for when this will take place at this stage. Discharging partially screened wastewater out to sea via the 1.8km long outfall pipe will allow for greater dilution of the wastewater in the Cook Strait, rather than untreated wastewater flowing around the coastline.
Even with this diversion, untreated wastewater will still need to be discharged via the short outfall. This is because the temporary arrangement can only accommodate dry weather flow.

To reduce the impact of odour and stop the process going septic, we are working to empty the clarifiers and Primary Settling Tanks. We estimate that this will continue for up to a week. During this time, we expect to see some discolouration around the coastline.

The sludge in the plant’s sludge holding tanks will be taken to Carey’s Gully as soon as possible. We estimate that this will continue for approximately a week/few days and will advise the local community as further plans are made. During this time, it is likely that there will be an increase in odour due to the plant being offline and the work taking place onsite. We will do all that we can to mitigate the impacts of odour.

The rāhui is still in place and covers anything the water touches/can touch with the high or low tides. While it is in effect, no public activities should be undertaken on or around the beaches on the southern coastline.
Health NZ advises the public to stay off the beach and avoid all contact with the water of the south coast. Check our map in our pinned posts for information on affected areas.

Do not collect or eat shellfish / kai moana from the affected coastal waters.

If you have been exposed to the water and develop symptoms such as vomiting, diarrhoea, fever, cough, rash, irritation of the ears, nose or throat, seek medical attention and inform the healthcare provider of your possible contact with sewage. Healthline is a free over-the phone health service available 24 hours a day, 7 days a week on 0800 611 116.

Further updates will be provided.

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UPDATE 3 - 9AM, 5/2
Staff are onsite at the impacted areas, distributing fliers and speaking with the local community. This will continue throughout the day.

Crews will be back onsite today, working to ascertain the full impact of the flooding on the plant’s equipment and operations. This assessment will take some time, and we expect that this will be an extended outage at the plant.
We are prioritising an investigation into diverting partially screened wastewater to the long outfall pipe.

Discharging partially screened wastewater out to sea via the 1.8km long outfall pipe will allow for greater dilution of the wastewater in the Cook Strait, rather than untreated wastewater flowing around the coastline.

A further update will be provided at approximately 11:30am, following the next emergency management meeting.
REMINDER: A rāhui is in place from Ōwhiro Bay to Breaker Bay. Please be aware that untreated sewage poses a high risk to public health. Due to the ongoing discharge of untreated wastewater via the short outfall pipe’s discharge point at Tarakena Bay, we strongly advise that people avoid the coastal area along the south of Wellington until further notice. Do not enter the water or collect kaimoana from this area.

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UPDATE 2 - 7:30PM, 4/2

- With power cut off at the plant and significant health and safety hazards present, it is unsafe for our teams to work onsite through the night.
- Tomorrow morning, staff will be at the areas impacted by the wastewater discharge, distributing fliers to the local community.
- Out of an abundance of caution, the sampling area has been increased to stretch from Breaker Bay to Seatoun. While we understand the risk of wastewater reaching from Tarakena Bay around to Seatoun to be very low, we are erring on the side of caution and completing sampling at these sites every 24 hours. The rahui extends to Breaker Bay, and does not cover the area of coastline through to Seatoun. However, we note LAWAs existing advice following the recent heavy rain. LAWA advises to not swim for 2-3 days following heavy rain.
This will be the final update for this evening. We’ll provide a brief update tomorrow morning, and a more fulsome update will be provided following tomorrow morning’s emergency management meeting at approximately 11:30am.

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UPDATE 1, 4:30PM, 4/2
Work continues at Moa Point Wastewater Treatment Plant, with all hands on deck to help with this issue. Teams will continue responding through the long weekend.

Our top priority is to protect public health and safety. Please be aware that untreated sewage poses a high risk to public health. Due to the ongoing discharge of untreated wastewater via the short outfall pipe’s discharge point at Tarakena Bay, we strongly advise that people avoid the coastal area along the south of Wellington until further notice. Do not enter the water or collect kaimoana from this area.

A rāhui has been placed from Ōwhiro Bay to Breaker Bay, and will remain in place until further notice. Signage is being placed around all impacted areas, and teams are continuing to door-knock local residents and businesses.
Sampling is occurring along the coast, and we are also assessing ocean currents to understand if wider sampling is needed.

We are working to ascertain the full impact of the flooding on the plant’s equipment and operations. This assessment will take some time, and we expect that this will be an extended outage at the plant. We are prioritising an investigation into diverting partially screened wastewater to the long outfall pipe. Discharging partially screened wastewater out to sea via the 1.8km long outfall pipe will allow for greater dilution of the wastewater in the Cook Strait, rather than untreated wastewater flowing around the coastline.

We have observed odour around the short outfall pipe’s discharge point. We are assessing options to mitigate odour in the short term, and protect the health and balance of the plant’s biological process to reduce the risk of any longer-term odour.

There are no impacts to the wider wastewater network or drinking water network. Drinking water remains safe to drink.

Please note that due to recent heavy rain, LAWA has designated areas around Wellington Harbour and the Eastern Bays in Lower Hutt as unsuitable for swimming. This is not related to the issue at Moa Point.

We’ll continue to keep you updated as work progresses.

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There is an ongoing discharge of untreated wastewater from Moa Point Wastewater Treatment Plant, that is impacting Wellington’s South Coast (Island Bay, Lyall Bay, Tarakena Bay).

Following an equipment failure, the plant has been shut down.
Our immediate focus is restoring power to the plant, resuming service, and diverting wastewater to the long outfall pipe, which will improve dispersion of the untreated wastewater and reduce impact on the coastline.

We strongly advise the community to stay away from the south coast beaches. There is currently untreated wastewater being discharged into the water and this may occur for some time.

- Public health signage is being erected at Lyall Bay and the south coast beaches. Untreated sewage poses a high risk to public health. We strongly advise that people avoid the coastal area along the south of Wellington until further notice. Do not enter the water or collect kaimoana from this area.
- A rāhui will be placed over the affected area.
- We have teams on the ground distributing information to the local areas about public health.

Wellington Water acknowledges that this is unacceptable and we apologise to the public, local community and our iwi partners for the public health and environmental impact caused.