Seaview Wastewater Treatment Plant Upgrades
We’re upgrading the Seaview Wastewater Treatment Plant on behalf of Hutt City Council and Upper Hutt City Council to reduce odour and discharges of untreated or partially treated wastewater and future-proof the plant, starting with odour improvement.
If you have any questions about this work, please contact:
Wellington Water, 04 912 4400
Latest Updates
We have made good progress in the past month and the plant is now close to normal operations. Our recent monitoring has indicated that with the reduction in sludge levels at the plant, odour levels have also generally reduced.
Urgent maintenance is being undertaken on one of the primary sedimentation tanks
The first step in improving odour treatment - replacing the biofilter media - was undertaken in December 2023. Find out more in the Updates section.
Odour treatment Renewal project
Work on the $13 million Odour Treatment Renewal Project is underway, with the initial planning phase complete. Detailed design and procurement are happening now in preparation for the physical works to commence this winter.
This project is prioritising areas for action that are most likely to make a significant impact on reducing odour escaping from the plant; the biofilter, milliscreening odour management and sludge drying odour management.
There’s more information on the project page. The work will be delivered in multiple packages. There are five high priority work packages in Phase 1 as follows:
The second phase includes two work packages; sludge dryer air treatment and further external ducting. Both will require an assessment of the effectiveness of the first phase in reducing odour issues. The sludge dryer air treatment also needs to be considered alongside plans to replace the sludge dryer.
The Seaview Wastewater Treatment Plant is aging. Much of the plant’s equipment and parts are nearing the end of their service life, which means it is more prone to service interruptions and needs more maintenance. Find more information about the plant’s performance and resource consents here
A multi-million-dollar programme of work is planned over the next six to 10 years to renew and upgrade equipment at the plant to improve its operation, subject to funding being confirmed. The current plan includes:
- Odour treatment renewal project (2024-2026)
- Sludge dryer replacement (2024 - 2028)
- Ultra-violet (UV) disinfection equipment renewal (2024 - 2026)
- Sludge pumps, aeration control system and aeration blowers (2024 - 2028)
- Clarifier ( 2026- 2028)
This work will contribute to reducing odour and discharges of untreated or partially treated wastewater, increasing capacity to handle population growth, and improving efficiency.
There is no quick fix, but Wellington Water is committed to short- and medium-term interventions to effectively manage operations of the treatment plant.
More detail on each area will be provided as planning progresses. Wellington Water is also considering options for reducing overflows to the Waiwhetū Stream and replacing the Main Outfall Pipeline.
FAQs
Is the plant meeting resource consent standards?
We are working hard to improve the current performance of the plant and the way we operate. Our focus is to meet the required standards and be compliant with the resource consents. The plant is aging, much of the equipment and parts are nearing the end of their service life, which means the plant is more prone to service interruptions and needs more maintenance.
Why are there no covers on the aeration or clarifier tanks at the Seaview plant?
Seaview’s aeration tanks do not pose a significant odour risk when they are operating according to design, as we are actively blowing air into a mixture of suspended aerobic microorganisms. The clarifier tanks which follow the aeration tanks also have a low odour risk. In the event of a breakdown in upstream treatment processes or a power failure, odour from the aeration tanks is possible. This risk is better addressed by ensuring we have effective equipment and systems, than by covering the tank. It is not common practice to cover tanks here or overseas, and not practicable at Seaview given the plant’s design.
Why are the treatment plants at Hastings, Gisborne and Napier totally covered?
Those plants use a different treatment technology and are constructed differently to the Seaview plant. It’s a bit like comparing diesel with petrol systems. The Hastings, Gisborne and Napier plants use trickling filter tanks and spray the wastewater over an open tank filled with algae that grows on plastic media. This does not happen at Seaview.
Why didn’t you replace the biofilter plenum (air distribution system) in December, when replacing the biofilter media??
During the works in December 2023 and following a condition inspection, it was discovered that the ‘plenum’ [biofilter structure] had degraded and should be replaced. It was necessary to proceed with the biofilter media replacement, as undertaking this additional work would delay the immediate objective of improving odour levels. Inspection of the plenum was only possible after we started removing the old biofilter media.
It was in the media that the work to replace the biofilter should have started in 2021, why the delay?
The biofilter media replacement was never programmed to be replaced in 2021. This work started in November 2023 after condition assessment and lab testing of bark composition, and the availability of a specialist contractor. The replacement was completed ahead of schedule in December 2023.
Is the biofilter media replacement making a difference?
While the new biofilter media is establishing well, there are ongoing issues with odour levels. Replacement of the biofilter media is only one part of the solution. We are continuing independent odour scouting, as well as monitoring complaints from the public, as we continue to work on other issues contributing to odour.
What upgrades do you have planned, how much will it cost?
We are prioritising improvements in three key areas we know are causing significant odour issues: the biofilter system, the milliscreening building and the sludge drying building. Hutt City Council has budgeted $13 million for these works.
Is the odour issue ever going to be fixed?
Wellington Water and Hutt City Council are committed to resolving the issue, though this is not an overnight fix, and it will take time. We acknowledge this is concerning, frustrating, and upsetting for everyone given it has been a long-term issue that has got worse in recent years.
Are there any health implications with plant associated odour?
When odour levels are strong and unpleasant, it can make some people feel ill. We are not aware of any health implications (bacteria that can be inhaled) and are following standard health and safety guidelines with the maintenance works we are doing at the treatment plant.
Te Whatu Ora - Health New Zealand has done an assessment on the use of the deodoriser at the Seaview Wastewater Treatment Plant. Please find the statement and more information here
Given the projected long-term investment, is the plant's current design under review?
We have concluded the design of the plant remains appropriate but much of the equipment needs renewing and upgrading, because the plant is aging, and equipment has deteriorated more quickly than expected.
We have also considered projected population growth and the standards we are required to meet by current resource consents.
The odour treatment renewal project is the first workstream in this long-term plan, followed by the sludge dryer replacement. There are other proposed upgrades for the UV system, sludge pumps, aeration control and clarifier. In addition, there is ongoing planned maintenance such as the milliscreen replacement, and reactive renewals (replacing smaller items that fail).
There is no quick fix, but Wellington Water is committed to upgrading the plant so we can continue to protect the health of people and the environment, while catering for population growth.
What odour neutraliser spray is used at the plant?
Odour Neutraliser Plus (SCD 1100)
For more information about the odour control product being used at the Seaview Wastewater Treatment Plant > Odour Neutraliser Plus Assessment
Update November 2024
We have completed stage one of the odour treatment renewal project, improving the biofilter.
Design work is underway on the next stage, capturing and delivering odourous air to the biofilter from covered areas of the plant, primarily the milliscreening room.
About the odour treatment renewal project
We’re investing $13 million in work to improve systems to capture and remove odours at the Seaview Wastewater Treatment Plant to avoid odours reaching the community.
The objective of the odour treatment renewal project is to improve the management of odour to ensure the plant is a safe environment and is operating within its resource consent.
We’re aware odour continues to be a problem, based on community feedback and our own independent scouting.
In the short term, we are prioritising areas for action that will result in capturing more odourous air from the milliscreening process and ensuring that the biofilter system is working effectively to remove odours from this air.
In the medium term, we are assessing options to improve odour management from the sludge dryer area, noting the dryer is due for replacement.
As well as replacing equipment, we’ll continue with maintenance and operational activity that we expect to contribute to reducing odour.
Treating odour
The Seaview Wastewater Treatment Plant uses physical and biological processes that harness the action of bacteria and other microorganisms to clean the wastewater. One of the side-effects of this process can be odour. The plant is designed to treat odours.
Odourous air is pumped to the biofilter, where is passes through a bed of media (mainly bark, gravel and limestone chip) containing microbes that break down the odour-causing compounds.
The Seaview plant also uses an odour neutraliser, which sprays a safe chemical mix into the air to neutralise odours.
Priority work
1: Improving the biofilter
When the biofilter media was replaced in December 2023, a comprehensive mechanical and structural condition assessment was undertaken. It became evident that:
- The air distribution system (plenum) in all six biofilter cells needs replacing.
- The biofilter cell isolation system needs redesign and upgrading to isolate each of the six cells individually, this would avoid odour discharge to the environment during routine maintenance events.
This work was completed in October 2024.
2: Capturing odours from the milliscreens
The wastewater screening room houses 10 inlet screens. These remove large solids from wastewater as it enters the plant. Find out more about the process here. This is typically the most odourous part of any wastewater treatment facility. The screens and channels are covered, with multiple ducts connected to the odour extraction system. This allows odourous air to be extracted with a fan and sent to the biofilter for treatment.
We know that there is an issue with the ducting from the milliscreens which is allowing odour to escape from the equipment into the building and then to outside. These ducts will be replaced to restore capacity.
We also plan to replace the fans that help extract odour around the plant.
3: Capturing and treating building air
While ducts capture air from the covered screens and channels, other air in the wastewater screening room vents directly to outside. We will upgrade the ventilation system to capture the building air for treatment before it is released. This is likely to involve installing new carbon air scrubbers in this building, subject to detailed design and planning being completed.
We are also looking at options for improving management of air from the sludge dryer building.
4: Repair External ducting
We know that some of the odour ducts running outside the buildings (external ducts) have leaks. This means that some of the captured odour escapes, and it also reduces the effectiveness of the fans in drawing out the odour from the different process areas. We have completed condition assessments on the external ducting and are planning how to repair leaks.
5: Process monitoring
Better monitoring of air flows will be built into all the above packages.
Phase 2
The second phase includes two work packages; sludge dryer air treatment and further external ducting, as required. Both of these would require an assessment of the effectiveness of the first phase in reducing odour issues. The sludge dryer air treatment also needs to be considered alongside plans to replace the sludge dryer.
Seaview Wastewater Treatment Plant Newsletter - December, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
Kia ora koutou
This special edition of the newsletter provides a summary of the findings from Part 1 of the odour neutraliser shutdown trial which finished on 18 December. We also provide an update on the actions arising from the community meeting held on 25 November, together with details of the current status of the plant and operations over the Christmas/New Year holiday period.
Odour neutraliser shutdown trial
Thanks to everybody who’s completed the survey so far. Part 1 of the trial to shut down the odour neutraliser finished on 18 December and the odour neutraliser was turned back on at 8am Thursday 19 December. Part 2 of the trial is to leave the odour neutraliser running for another two weeks until 2January 2025.
Please continue to complete the survey until 2 January 2025. This will help us establish a ‘baseline’ from which we can assess the trial to help us understand whether the smell is better, worse or the same as it has been before the shutdown. We acknowledge the plant has not been in a normal operating state and will take that into account.
The odour survey is simple and very quick to complete. We appreciate your help with this.
We will continue to keep you updated on the progress throughout this next stage of the trial period via our interested parties’ email and our Facebook page - https://www.facebook.com/wellingtonwater.
Following the completion of the trial, we will undertake a process of review and assessment of the results. We will keep you informed as we work our way through this in the New Year. Feedback from the community will help Wellington Water and Hutt City Council determine our next steps.
A summary of the discussions at the meeting and issues raised, presentations from speakers alongside a Q&A document will be made available on our website over the next week. We will send out a link to this once it has been published.
Summary of responses so far from the trial
We received 241 responses to the survey over the period of Part 1 of the trial. Responses to the survey have been relatively low but we did receive a significant number of responses (119) on 6 December.
Odour levels during Part 1of the trial period confirm that odour remains an issue at the plant. The results show varying levels of impact based on location and weather conditions.
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Rate the smell between 1 and 5 |
How does the smell compare to previous months |
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Of responses rating the odour at 4 or 5, how did the odour compare to previous months |
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Odour levels were most frequently and strongly smelt at Seaview and Waiwhetu.
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Seaview |
Waiwhetu |
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83 respondents 56 rated odour at 4 or 5 |
60 respondents 28 rated odour at 4 or 5 |
During the trial, odour scouting was also undertaken daily. The findings of the odour scouts align with improvements in plant health and feedback received from the community. The winds were predominantly northerly meaning more odour was observed south of the plant than north. Odour levels were strongest in locations closest to the plant and in areas at the plant where work was being undertaken. Scouting is planned to continue 1-2 days per week in the New Year.
During the period of the trial, work has continued to bring the plant back to optimal operational performance and reduce the risk of increased odour levels over the holiday period. We appreciate this makes it challenging to make an accurate assessment of the effectiveness of the odour neutralisers. This means the results of the survey and odour monitoring need to be considered in the context of work at the plant that may lead to increased odour levels (e.g. transporting dewatered sludge to landfill) and other changes to processes at the plant to increase solids processing (e.g. Dissolved Air Flotation optimisation trial). Further details about this work and the current status of the plant are provided further in this newsletter.
A summary of the responses received from Part 1 of the trial (4-18 December) is available on our website – see https://www.wellingtonwater.co.nz/assets/The-Network/Wastewater/Wastewater-Treatment-Plants/Seaview/Odour-neutraliser-trial-survey-results_Part-1_website.pdf
Plant performance and operations
Current status of the plant
We have made good progress in the past month and the plant is now close to normal operations. Our recent monitoring has indicated that with the reduction in sludge levels at the plant, odour levels have also generally reduced.
Two key indicators of the health and balance of the biological process at the plant are levels of Mixed Liquor Suspended Solids (MLSS) and Dissolved Oxygen (DO). MLSS measure the volume of solids in the aeration tanks where bacteria feed on organic material in the wastewater. Providing the right range of Dissolved Oxygen (target range 1 to 3), gives the bacteria the best conditions to grow.
Below is a summary of how these indicators have been tracking since the outages with the dryer in September and October.
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Mixed Liquor Suspended Solids (MLSS) |
Dissolved oxygen (DO) |
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9 October |
5,760 |
0.69 |
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23 October |
5,070 |
0.67 |
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5 November |
5,230 |
0.83 |
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19 November |
4,800 |
0.67 |
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4 December |
4,350 |
0.69 |
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18 December |
2,560 |
2.11 |
While there is still some work to do to return the plant to the level that it was operating at before the incidents with the dryer, we are pleased to see a marked improvement in both indicators.
Operations over the holiday period
Preliminary cleaning of Primary Sedimentation Tank #2 has been completed in advance of repairs to be undertaken after parts arrive in mid-January. Work on the repair to Blower #2 has also been completed.
To keep the plant stable and minimise odour, we will be limiting planned maintenance and pausing non-critical work at the plant over the holiday period. The trucking of dewatered sludge to landfill will also stop from end of day Friday 20 December.
Routine operation of the plant and dryer will continue. Veolia, our plant operators will be monitoring key process points of the plant during the holiday period. Work has been undertaken to build resilience to plant operations, with resources on call and escalation processes in place to respond to any incidents that may arise.
The weekly updates on odour levels and plant operations recently provided will stop over the holiday period. We will follow our usual procedures for notification to the community of any unplanned outages, maintenance or operational incidents at the plant.
Actions from the community meeting
A summary of the notes from the community meeting held on 25 November, as well as a copy of the presentation on plant operations has been published on our website – Seaview Wastewater Treatment Plant Community Meeting Notes, Actions, and Presentation Slides.
Increased odour monitoring
We are continuing to investigate the right type of monitors that we could use to increase our monitoring of odour from the plant. We have met with the team at Christchurch City Council about the monitors that they have used. Our engineering team are completing their initial evaluation, and we will provide a further update in the New Year.
Updates on potential for high odour levels
We have continued to provide weekly communications to the community about operations at the plant that could impact on odour levels via our interested parties email list and posted updates on our website and Facebook page.
We are committed to making this information as accessible and transparent as possible so are looking at other formats to present these updates and to increase visibility on our website. We acknowledge that wind direction impacts odour levels and will explore how we can provide this as an added layer of information on our website.
We will keep you updated on progress with this work which requires further investigation and changes to our website.
Keep in touch
You are receiving this email because you have expressed an interest in the plant. Please feel free to share this with others who may be interested.
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Join the mailing list for plant notifications and this monthly update at customer.notifications@wellingtonwater.co.nz.
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If you have any questions relating to this newsletter email community@wellingtonwater.co.nz.
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For complaints relating to specific incidents or properties go to customer@wellingtonwater.co.nz.
Thank you!
Blair Johnson
Head of Wastewater Contracts
Seaview Wastewater Treatment Plant Upgrades - November 2024
Seaview Wastewater Treatment Plant Newsletter - November/December, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
Kia ora koutou,
Welcome to the regular update about the operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work. This is the last newsletter for 2024 but email updates will continue, and you can find the latest information on the website.
In this issue
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Community meeting update
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Next steps
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Update on work at plant
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Wastewater Treatment Plants Treatment Services contract review
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Plant performance update
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Keep in touch
Community meeting update
Thank you to those who attended the community liaison meeting on Monday 25 November.
We know it has been an extremely stressful time for the community. We appreciated the opportunity to have a face-to-face conversation to discuss recent issues that have resulted in increased odour from the plant.
The Mayor of Lower Hutt, Wellington Water Chief Executive and staff, and senior management from plant operators, Veolia, spoke at the meeting. Chief Executive, Hutt City Council Jo Miller was also in attendance. They all reiterated that the Seaview Wastewater Treatment Plant is a top priority and that the level of odour is completely unacceptable. However, all speakers also emphasised that there is no quick fix or silver bullet to reducing the odour from the plant. It is likely there will be intermittent occurrences of increased odour at the plant for a while as we work to replace and upgrade aging equipment at the plant.
Community members spoke about the emotional toll of the stench and the ongoing impact on their wellbeing, their businesses, and their house prices.
All speakers acknowledged the huge impact on the community. Mayor Campbell Barry said what the council can do is give people confidence that everything possible is being done to fix the problem.
Wellington Water's CE Pat Dougherty assured the community that Wellington Water and Veolia would be doing all they could to minimise odour over the holiday period. This included avoiding any maintenance or upgrades that might cause odour levels to increase.
We were especially grateful that the meeting was conducted respectfully, with a safe space for all speakers to talk freely and share information without interruption. We appreciate all the questions and comments from the community which have given us some things to take away and review.
In response to the concerns raised by the community at the meeting, we are working on three key actions/next steps:
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Turning off the odour neutralisers to see if this reduces the impact on the community, without increasing odour effects.
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Increase monitoring of odour from the plant.
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Providing the community with more timely and frequent information about the likelihood of high odour levels from the plant so people can plan.
A summary of the discussions at the meeting and issues raised, presentations from speakers alongside a Q&A document will be made available on our website over the next week. We will send out a link to this once it has been published.
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Next steps
To help us to assess the impact and effectiveness of the trial, we are asking the community to fill in a quick online odour survey daily to let us know of your experience of odour levels. You can fill in this survey up to three times a day – morning, noon, and evening or whenever you notice a smell.
If there is significant negative impact experienced by the community during the trial, it will be shut down earlier than planned. We will be monitoring feedback, odour scouting results and complaints very closely throughout the trial.
Increased odour monitoring
We need to consider the types of monitoring that will be fit-for-purpose for our environment, and this may take us a bit of time. We are working on this, and we have our engineering team exploring options.
Once we have further information and options to do this, we will seek community feedback and input.
More timely and frequent updates on potential for high odour levels
As this requires further investigation and changes to our website, this is not something we can do immediately. We will keep you updated on progress via email.
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Update on work at the plant
The recent sludge dryer outages caused a backlog of sludge in the system, throwing the biological waste treatment process out of balance. This contributed to the odour, as did the need to truck sludge that had not been dried to the landfill.
The dryer is now back online, and we are making progress with clearing the backlog. However, we will need to keep intermittently trucking some sludge to the landfill to help clear the backlog as quickly as possible. This is scheduled to resume on Tuesday, 3 December. We have erected scaffolding and cover in the area where sludge is being loaded to reduce the odour when this process is being undertaken.
Improvements in the biological process have been noted and we are doing all we can to get the process back into balance with the plant operating at design levels as soon as possible.
The reports on the fire and mechanical failure will be made available on our website when completed.
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Wastewater Treatment Plants Services contract review A review of the Wastewater Treatment Plants Services contract was recently completed. You can read the full report on the review which has been published on our website.
Plant operators Veolia are reorganising their operations at Seaview and other plants they operate under contract to Wellington Water.
Following the review Veolia have engaged a global taskforce to enhance access to international expertise, invested in further staff training, updated their communication structures to meet the needs of stakeholders and regulatory compliance, and ensured clear organisational focus on critical areas including preventative maintenance.
Go to our website to read the full report of the review - https://www.wellingtonwater.co.nz/assets/Reports-and-Publications/RWWTP-Review-Cover-note-and-report-..pdf
Plant performance update
The dashboard also confirms that the plant remained non-compliant for faecal coliforms because the treated effluent has exceeded the set limit for bacteria on more days than permitted over a 90-day period. The level of risk to public health is low because this is treated wastewater which is pumped into the sea near Pencarrow Head/Te Raeakiaki, where it is quickly diluted.
The Annual Resource Consents and Compliance reports for the Seaview Wastewater Treatment Plant have also been published on our website.
The performance dashboard for October and Annual Resource Consents and Compliance report can be viewed on our website – go to
Keep in touch You are receiving this email because you have expressed an interest in the plant. Please feel free to share this with others who may be interested.
community@wellingtonwater.co.nz.
Thank you for taking the time to read this information. Be assured we are doing all we can to avoid offensive odours from the plant over the summer.
We wish you all the best for the holiday season.
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Seaview Wastewater Treatment Plant Newsletter - October 2024
Seaview Wastewater Treatment Plant Newsletter -November 1, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
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Seaview Wastewater Treatment Plant update - September 2024
Seaview Wastewater Treatment Plant Newsletter -October 3, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
Kia ora koutou
Welcome to the monthly update about Wellington Water’s operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work.
You’re receiving this email because you expressed an interest in the plant. Please feel free to share this with others who may be interested.
You can join the mailing list by emailing customer.notifications@wellingtonwater.co.nz.
In this issue:
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Community message
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Sludge dryer back in service
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Biofilter air distribution system renewal
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Odour Treatment Renewal Project
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Ultraviolet disinfection upgrade
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Primary sedimentation tank mechanical renewal (second tank)
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Petrochemical investigation
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Trade waste planned maintenance
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Plant performance update
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Get in touch
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Seaview Wastewater Treatment Plant Newsletter - August 2024
Seaview Wastewater Treatment Plant Newsletter -August 31, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
Kia ora koutou
Welcome to the monthly update about Wellington Water’s operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work.
You’re receiving this email because you expressed an interest in the plant. Please feel free to share this with others who may be interested.
You can join the mailing list by emailing customer.notifications@wellingtonwater.co.nz
In this issue:
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Biofilter air distribution system renewal
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Primary sedimentation tanks mechanical renewal
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Plant performance update
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Seaview Wastewater Treatment Plant Newsletter - July 2024
Seaview Wastewater Treatment Plant Newsletter
July 31, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
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Kia ora koutou You’re receiving this email because you expressed an interest in the plant. In this issue:
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Upcoming work Over the next two to three months, we are undertaking work at the plant to improve its performance and odour management. This is being done in three areas of the plant that may cause some intermittent odour outside the Seaview Wastewater Treatment Plant boundary while the work is underway.
We have scheduled these works to overlap to minimise the time the community may notice an impact. We’re also doing this work when the weather is cooler because there’s generally less odour in the colder months. We will be using the odour neutraliser to minimise offensive odour and will be monitoring the odour beyond the plant. We ask for your patience with any short-term increase in odour while we make these long-term improvements to the plant. Further details about this work is provided below. |
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Seaview Wastewater Treatment Plant Newsletter - June 2024
Seaview Wastewater Treatment Plant Newsletter June 30, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
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Get in touch RSVP for the odour treatment renewal project update, at community@wellingtonwater.co.nz Join the mailing list for plant notifications and this monthly update, at customer.notifications@wellingtonwater.co.nz If you have any questions relating to this newsletter, at community@wellingtonwater.co.nz For complaints relating to specific incidents or properties go to customer@wellingtonwater.co.nz Thank you for taking the time to read this information.
Linda Fairbrother Blair Johnson Project Lead, Major Projects Head of Wastewater Contracts |
Seaview Wastewater Treatment Plant Newsletter - May 2024
Seaview Wastewater Treatment Plant Newsletter May 31, 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
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Seaview Wastewater Treatment Plant Newsletter - April 2024
Seaview Wastewater Treatment Plant Newsletter April 2024
Your latest news on what's happening at the Seaview Wastewater Treatment Plant
Kia ora koutou,
Welcome to the second of our regular monthly updates about Wellington Water’s operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work.
You are receiving this email because you have expressed an interest in the plant. Please feel free to share this with others who may be interested. You can join the mailing list by emailing customer.notifications@wellingtonwater.co.nz
We would like to offer a tour of the plant to anyone who’s interested, likely on a Saturday afternoon. Please get in touch to express your interest by emailing community@wellingtonwater.co.nz. We’ll follow up in the coming month to confirm dates and numbers.
In this issue
- Odour Treatment Renewal Project update
- Plant performance update
- Plant maintenance
- Community meeting
- What's next
- Get in touch
Odour treatment Renewal project
We can confirm that work on the $13 million Odour Treatment Renewal Project is underway, with the initial planning phase complete. Detailed design and procurement are happening now in preparation for the physical works to commence this winter.
As a reminder, this project is prioritising areas for action that are most likely to make a significant impact on reducing odour escaping from the plant; the biofilter, milliscreening odour management and sludge drying odour management.
There’s more information on the project page. The work will be delivered in multiple packages. There are five high priority work packages in Phase 1 as follows:
The second phase includes two work packages; sludge dryer air treatment and further external ducting. Both will require an assessment of the effectiveness of the first phase in reducing odour issues. The sludge dryer air treatment also needs to be considered alongside plans to replace the sludge dryer.
Plant maintenance update
Milliscreening room
The odour ducts in the milliscreen area have been cleaned with high pressure water. This will enable more air to be drawn from the screen hoods to the biofilter for treatment, rather than escaping untreated, and we would expect this to contribute to reducing odour from the plant.
The image above shows the wastewater screening room. There are 10 inlet screens that remove large solids from wastewater as it enters the plant. The screens themselves rotate inside the blue hoods, and the white pipes carry the odourous air from the hoods to be treated.
Maintenance is planned soon for one of the four primary sedimentation tanks (PST) which removes the settleable solids (such as sand and larger organic particles) from the wastewater. The tanks have a mechanical system that scrapes the solids out, but some components of this system are worn out and need replacing.
Because we will be opening the tank, there is a risk of odour. We will use an odour masking system to mitigate the effects and advise you of works in advance.
Once this is completed, we will move on to draining and maintaining one of the four aeration tanks, which facilitates the biological treatment process of wastewater. The date for this work to be confirmed.
Veolia has commissioned a report into the effectiveness of the biofilter media replacement in December. It concluded that while the media replacement recorded an improvement on the performance of the odour treatment, further works are required for restoring it to optimum working condition.
This assessment supports the decision already made that the air distribution system within each cell, will be upgraded as part of the phase 1 priority works. It also provides a baseline to assess the effectiveness of the plenum (biofilter) upgrade work.
Plant performance update
Unfortunately, the plant is still not compliant with one of three standards for the treated wastewater pumped out to Cook Strait, as reported in the March performance dashboard available on the website.
Since last September, effluent has exceeded the set level for bacteria, of 5000 cfu(colony forming units) per 100 millilitres at least 80% of the time.
The level of risk to public health is low, because this treated wastewater is pumped into the sea near Pencarrow Head/ Te Raeakiaki where it is quickly diluted, however, we are are taking steps to address this.
This includes making improvements to the biological process and the ultra-violet (UV) disinfection system (which destroys bacteria). Monthly shoreline sampling is being undertaken and the bacteriological levels (enterococci) on the sites being monitored are below LAWA's alert trigger level of 140 cfu/100 mL.
The report records one discharge to Waiwhetū Stream in March and there was another in April. This was due to wet weather events increasing the amount of stormwater getting into the wastewater system. These discharges are permitted under the resource consent, but we are looking at long-term solutions to reduce or avoid this type of discharge.
In the interim, we are talking to Greater Wellington Regional Council (GWRC) about the signage around the stream.
There was also an unplanned discharge to the coastal marine area at Pencarrow in March, due to a power outage. We are providing more information to GWRC about this.
In March, we received 16 complaints about odour at the plant.
Community meeting
Councillor Brady Dyer has followed up on discussion about whether a new Council 'request for service' system would provide for odour complaints more efficiently. He advises that the Te Kahu Tāniko Customer-Centric Systems (CCX) project is well underway to address this.
This project will deliver a new customer portal and management system to handle issues more effectively and keep customers up to date on progress. Council staff are currently working with key contractors and stakeholders including Wellington Water to create an effective system. At this stage the project is expected to be complete in early 2025.
In the meantime, you can report odour issues by calling Hutt City Council or via Report A Problem on their website . All issues are reported to Greater Wellington Regional Council.
Next month
- Detailed design of the priority work packages will continue
- A report on the summer odour scouting programme
- Notifications of odour issues and wastewater overflows
- Proposed plant tour update
Get in touch
To register interest in a plant tour, email community@wellingtonwater.co.nz.
Join the mailing list for plant notifications and this monthly update, please email customer.notifications@wellingtonwater.co.nz.
If you have any questions regarding this newsletter, email community@wellingtonwater.co.nz.
For complaints relating to specific incidents or properties, email customer@wellingtonwater.co.nz.
Thank you for taking the time to read this information.
Linda Fairbrother Project Lead, Major Projects
Blair Johnson Head of Wastewater Contracts
Seaview Wastewater Treatment Plant Newsletter - March 2024
Kia ora koutou
This is the first of what will become regular monthly updates about Wellington Water’s operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work.
You are receiving this email because you have expressed an interest in the plant. Please feel free to share this with others who may be interested. People can go on the mailing list by emailing customer.notifications@wellingtonwater.co.nz
Because this is the first newsletter, we thought some background would be useful.
The big picture
The Hutt Valley wastewater network including the plant is aging and needs upgrading, to ensure we can continue to protect the health of people and the environment, while catering for population growth.
The plant cleans and disinfects wastewater from about 160,000 people each day. However much of its equipment and parts are nearing the end of their service life, which means its more prone to service interruptions and needs more maintenance.
The plant’s equipment has deteriorated more quickly than expected, and the volume of wastewater to be treated has increased.
There is a multi-million-dollar programme of work planned over the next six to 10 years to renew and upgrade equipment at the plant, subject to funding being confirmed. This includes ongoing work looking at how to reduce overflows into the Waiwhetū stream.
The first priority is reducing offensive and objectionable odours from the plant. Wellington Water understands the community’s frustration with ongoing odour issues and is committed to improving odour control.
Odour control
Hutt City Council has committed $13 million to enable Wellington Water to get underway with work needed to improve odour control at the plant.
We appreciate the time of those who came to a community meeting on Thursday 21 March to discuss our plans to improve odour control, and the overall performance of the plant.
Those at the meeting raised some good questions and we are gathering information to answer those. There are some questions and answers on the project page on the Wellington Water website and more information will be added.
In brief, as set out in the presentation slides we outlined that the odour is coming from three main sources at the plant:
- Biofilter - the biofilter media (the biological material that filters air) was replaced in December, but it takes time for the biological process to get established. We also know the air distribution system (plenum) beneath the media needs renewal.
- Milliscreening process - odours are escaping because ducting taking air directly from the milliscreening equipment needs repairing and replacing, and because other air in the wider building is not captured by the odour control system.
- Sludge dryer building - this part of the process emits a different type of odour, and we are looking at solutions here.
A project team is working on solutions across these areas including:
- Upgrading the air distribution system in the biofilter
- Replace ducting and fans where required including from the milliscreening building
- Putting additional odour treatment into the milliscreening building and potentially the dryer building, noting the sludge dryer is due for replacement in coming years.
We’ll be keeping you updated through this newsletter and posting more details including timeframes on the website page as they are confirmed.
Current plant performance
We are unfortunately not fully meeting the standards set in the resource consents governing the operation of the plant. Greater Wellington Regional Council’s annual compliance report was discussed at last week’s meeting and is available here.
We are taking steps to address the issues, including operational improvements, ongoing maintenance and the upgrade programme referred to above.
Our most recent monthly dashboard report on the plant shows that we are still not compliant with one of three effluent quality standards in the resource consent; that is, the plant is non-compliant.
We are also not meeting consent requirements that there will be no offensive or objectionable odour outside the plant’s boundary. We recorded 41 odour complaints in February (additional to those received before February).
While there were no wet weather overflows into the Waiwhetū Stream in February, the GWRC annual compliance report noted that there were 26 discharges in the 2022-23 year. These are discharges of fully treated wastewater, acknowledging that at times the treatment process has not been meeting standards. Interested parties are notified when these discharges happen and there is some signage near the outfall. The signage will be reviewed following discussion at Thursday’s meeting. Wellington Water recommends all recreational water users follow the advice of Land, Air, Water Aotearoa (LAWA) to avoid swimming for at least 2 - 3 days after heavy or prolonged rain.
Effluent bacteria levels
Under the consent, the effluent (the treated wastewater pumped out to Cook Strait) should be within set levels of organic material (cBOD or readily biodegradable organic carbon), suspended solids and bacteria (faecal coliforms).
Since September, the effluent has exceeded the set level for bacteria, of 5000 cfu (colony forming units) per 100 millilitres at least 80% of the time. This is not acceptable, because of the potential risk to public health and the environment. It’s important to note the level of risk to public health is low because this treated wastewater is pumped into the sea near Pencarrow Head/ Te Raeakiaki where it is quickly diluted.
The outfall is well away from recreational areas and well sign posted. However, we aim to meet all standards, and we are taking steps to return the plant to compliance as soon as possible. This includes making improvements to the biological process and the ultra-violet (UV) disinfection system (which destroys bacteria).
_________________________________________
Next month
>The odour control project plan and timetable will be finalised
>Preparation for the biofilter air distribution system replacement will progress, including finalising the design, procuring contractors and equipment.
>Condition assessments of the ducting and fans and other elements will continue, with any ‘quick fixes’ identified to be addressed as soon as possible.
>The odour scouting programme will continue. This involves independent ‘noses’ visiting the area at a range of times and reporting odour levels. This is providing useful data to assist with our planning, alongside the valuable information from residents’ complaints.
>Notifications of odour issues and overflows will continue to be sent to you as they occur.
Get in touch
- Join the mailing list for plant notifications and this monthly update, or if you want to be removed from the mailing list, please email customer.notifications@wellingtonwater.co.nz
- For any questions relating to this newsletter, email community@wellingtonwater.co.nz.
- Any complaints relating to specific incidents or properties should go to customer@wellingtonwater.co.nz
- Thank you for taking the time to read this information.
Linda Fairbrother Blair Johnson
Project Lead, Major Projects Head of Wastewater Contracts
All Updates
Current status of the plant
We have made good progress in the past month and the plant is now close to normal operations. Our recent monitoring has indicated that with the reduction in sludge levels at the plant, odour levels have also generally reduced.
Two key indicators of the health and balance of the biological process at the plant are levels of Mixed Liquor Suspended Solids (MLSS) and Dissolved Oxygen (DO). MLSS measure the volume of solids in the aeration tanks where bacteria feed on organic material in the wastewater. Providing the right range of Dissolved Oxygen (target range 1 to 3), gives the bacteria the best conditions to grow.
Below is a summary of how these indicators have been tracking since the outages with the dryer in September and October.
|
|
Mixed Liquor Suspended Solids (MLSS) |
Dissolved oxygen (DO) |
|
9 October |
5,760 |
0.69 |
|
23 October |
5,070 |
0.67 |
|
5 November |
5,230 |
0.83 |
|
19 November |
4,800 |
0.67 |
|
4 December |
4,350 |
0.69 |
|
18 December |
2,560 |
2.11 |
While there is still some work to do to return the plant to the level that it was operating at before the incidents with the dryer, we are pleased to see a marked improvement in both indicators.
Operations over the holiday period
Preliminary cleaning of Primary Sedimentation Tank #2 has been completed in advance of repairs to be undertaken after parts arrive in mid-January. Work on the repair to Blower #2 has also been completed.
To keep the plant stable and minimise odour, we will be limiting planned maintenance and pausing non-critical work at the plant over the holiday period. The trucking of dewatered sludge to landfill will also stop from end of day Friday 20 December.
Routine operation of the plant and dryer will continue. Veolia, our plant operators will be monitoring key process points of the plant during the holiday period. Work has been undertaken to build resilience to plant operations, with resources on call and escalation processes in place to respond to any incidents that may arise.
The weekly updates on odour levels and plant operations recently provided will stop over the holiday period. We will follow our usual procedures for notification to the community of any unplanned outages, maintenance or operational incidents at the plant.
We continue to make progress on returning the plant to normal operations.
Our monitoring of odour over the past week has indicated that odour levels appear to be reducing.
Progress with clearing the backlog of sludge is steady and we will continue to truck dewatered sludge to landfill until 20 December. We expect to complete cleaning of the primary sedimentation tank #2 by 18 December. The trial to optimise the processing of sludge before it moves into the centrifuges and dryer has helped with increased production of dewatered sludge. This is an important step towards restoring the plant to a balanced state.
As advised, we will be pausing planned maintenance and other activities over the Christmas/New Year break to minimise odour levels. We are working with Veolia on the plan to manage plant operations during this period.
We will be sending out a final Seaview Wastewater Treatment Plant newsletter for the year around 20 December. This will include details of this plan, as well as an update on the actions arising from the community meeting held on 25 November.
The trial to shutdown the odour neutralisers is continuing. Thanks to all who have completed the survey to date. Response numbers have slowed down and we encourage you to share the link to the survey to people impacted by odour levels from the plant. Please continue to submit responses via the survey. This will help us to assess the impact of not using the odour neutraliser on odour levels experienced by the community.
For more information about the trial and update on latest survey results, see here.
As advised in our update on 6 December 2024, urgent maintenance is being undertaken on one of the primary sedimentation tanks (PST). The PSTs process solids before they are sent off to sludge treatment.
Work will be starting on 9 December 2024 to clean PST #2 and is expected to take 3-4 days. The work is an important part of our proactive programme of maintenance to keep the plant operating efficiently, especially with the summer period approaching.
There is a risk of increased odour at the plant while this maintenance work is being undertaken. We are hopeful that odour will be minimised with the good progress made in clearing the backlog of sludge, changes made to improve the efficiency of the process and progress to restoring the balance of the plant.
We will monitor odour levels closely while this work takes place. Please contact the regulator, Greater Wellington Regional Council if you experience an increase in noticeable odour.
Work is continuing on restoring the plant to normal operations which is vital to reducing odour levels.
The dryer is back in operation, and we are making progress with clearing the backlog of sludge. We resumed trucking dewatered sludge to landfill on 3 December and expect to continue doing this until 18 December. This is being done to supplement the dryer and get the plant to normal operations as quick as we can. There is a risk of increased odour at the plant while this process is being carried out. We have erected scaffolding and cover in the area where dewatered sludge is being loaded and are using two fully covered bins that have been transferred from Porirua. This will help reduce odour levels during the load out and trucking of sludge to landfill.
We have additional consultants on site working closely with Veolia to assist with proactive monitoring of the operation of the plant. They are also making recommendations on ways to further improve efficiency as well as any changes that could help to accelerate restoring balance of the plant.
We are working through the recommendations made for improvements in the sludge removal processes. These are focused on optimising the processing of sludge before it moves into the centrifuges and dryer. Early results of this work are positive and will keep you updated on progress.
We are expecting the arrival of replacement parts for Blower 2 on 16 December. When the repair is completed around 19 December, all three blowers will be back in service at the plant.
Urgent maintenance is required on one of the primary sedimentation tanks. This is part of a proactive programme of maintenance critical to the continued efficient operation of the plant. This work will be starting over the next two weeks. There is a risk of increased odour while this work is being carried out. We have plans to minimise this and will be monitoring odour levels closely during this time.
We will be pausing work on the tanks as well some other activities over the holiday period to minimise odour levels. We are also planning to not truck dewatered sludge to the landfill during this period. Routine operation of the plant and dryer will continue.
A well-attended community meeting on the Seaview Wastewater Treatment Plant on Monday 25 November heard from the Mayor of Hutt City Council who outlined that the Seaview Wastewater Treatment Plant is a top priority for Hutt City Council and that the level of odour is completely unacceptable. This has been made clear to Wellington Water and through them Veolia.
Both HCC and UHCC have committed to $230M over ten years of investment in the plant. With this funding and workplans the odour levels will be mitigated although not completely eliminated due to the nature of the plant’s operation
Wellington Water Chief Executive Pat Dougherty and senior leaders of Wellington Water, along with plant operators Veolia apologised for the unacceptable odour from the plant. The most recent increase in odour was caused by two small fires and equipment failure in the sludge dryer in September.
Veolia said this was a challenging and an unacceptable situation. They acknowledged and recognised their accountability to deliver the right outcomes in the community. They also said the community could expect better and was determined to deliver better. They noted this won’t be easy as there are similar ageing infrastructure challenges across New Zealand every day.
The meeting also heard about Wellington Water and Veolia’s plans to replace the sludge dryer and make other improvements (further details on the website here)
Pat Dougherty said the sludge dryer is due to be replaced in three to four years. He said that even when the old equipment has been replaced, there may be some odour. He said Wellington Water is doing everything it can to get the plant running properly, reducing the likelihood of odour reaching people’s homes, but it is not possible to guarantee the odour will stop indefinitely.
There was discussion about a number of issues including the odour neutraliser spray in use, funding, planning for the future and the impact on health and wellbeing, property values and businesses.
Wellington Water agreed that, in response to the community’s wishes, it would trial turning off the odour neutralisers in use at the plant. More details will be provided once plans are confirmed.
Wellington Water agreed to investigate improving communications drawing on the experience in relation to the Bromley Wastewater Treatment Plant in Christchurch.
Actions from the meeting:
Odour monitoring at the plant – looks at ways to communicate regularly on status on the WWL website. Consider network connected hydrogen sulphide and other monitoring such as wind direction.
Communications – more regular updates including looking at ways to reach people (letterbox drop). Consider interactive map with condition and work plan for each pond (traffic light system)
Trial not using odour blasters with advance notice to the community on days this would be happening. This information would be published on the WWL website.
Community concern about having to continually raise the odour issue by lodging complaints will be better managed through more regular communications.
Seaview Wastewater Treatment Plant - Community Meeting Notes, Actions, Presentation Slides, and Talking Notes - 25 November 2024
Plant operation update
The sludge dryer, which has an important role in reducing the volume of sludge before it is taken to landfill, is now back up and running at the plant. This will improve the efficiency of plant operations and help minimise odour.
With the dryer back in operation, we have reduced the amount of sludge being transported to landfill but this will continue intermittently to reduce solids in the process, particularly when the dryer is taken down for maintenance. We still have odour neutralisers located where the sludge is loaded into the trucks, to minimise odour as much as possible.
Maintainance work begins today on one of the primary sedimentary tanks, which involves draining down the tank and moving solid matter. This may cause odour, but we have mitigations in place including a deodoriser to reduce the smell as much as possible. We’ll be regularly monitoring the odour while the work takes place.
Please be assured we’re doing everything we can to minimise odour. We’ll keep you updated on any key operational updates, and provide another update next week.
Work continues to reduce the backlog of dewatered sludge, before bringing the sludge dryer back into service – scheduled for early next week, but earlier if possible.
We’ve increased the amount of sludge being transported to landfill, from around 8 tonnes, to 50 tonnes per day. This helps us reduce the sludge backlog quicker, support efficient plant operations and minimise odour as we head into summer. The sludge backlog was a result of the sludge dryer outages that happened in September and October.
The sludge transportation is likely to result in increased odour as we load the trucks. We have moved one of the odour neutralisers at the plant to where we are loading the trucks to reduce the odour as much as possible. We apologise for any increased odour that you may have experienced at the plant since this work started. We expect odour to improve early next week when we bring the sludge dryer back into service.
Our team are also investigating potential issues with one of the primary sedimentary tanks and one of the blowers at the plant. These issues could impact the overall performance of the plant. We are working as fast as we can to have these issues resolved as soon as possible.
Please be assured we are doing all that we can to reduce odour levels. We have brought in an external expert to provide additional support and focus on plant operations and to provide recommendations to accelerate the solids removal process.
We’ll continue to closely monitor the situation and have another update to share early next week.
Over the past month, we have been using a chemical supplement to help accelerate the level of sludge removal at the plant.
While this is a standard practice for operation of the plant, it is the first time that we have used this for a sustained period, in this amount and for this part of the treatment process.
The chemical supplement has been successful in reducing the backlog of sludge at the plant because of the outages in September. The biological process remains stable, however, use of this supplement to clear the backlog has disrupted the operation of the sludge dryer.
We have been working hard to keep the dryer running, however this chemical supplement process has changed the characteristics of the dewatered sludge that is fed into the dryer. This is creating significant issues with components in the system and resulted in a shutdown of sludge drying over the weekend.
Dewatering has continued but the dryer is not in service. There is currently a backlog of dewatered sludge that must be cleared before the dryer can be brought back online.
We will be increasing the volume of dewatered sludge transported to landfill per day to clear this backlog. The trucks will be wrapped and sealed during the transportation process but there is a risk of increased odour during loading into the trucks. We will do our best to mitigate this and are trialling options to stabilise the dewatered sludge to minimise odour before it’s loaded into the trucks.
Our operations team have advised that use of the chemical supplement is no longer sustainable. Our priority is to minimise the risk of increased odour levels returning to the plant. We are working hard to keep the amount of sludge at the plant at a manageable level as the plant continues progress to a return to normal operations.
We acknowledge the events in September and early October were very unpleasant and distressing to the community. Please be assured we are doing all that we can to prevent a recurrence. We advise residents to contact the regulator, Greater Wellington Regional Council if they experience an increase in noticeable odour.
We are making progress with restoring the plant to normal operations following the sludge dryer outages.
We thank the community for your patience as we continue this work. While it’s taking longer than expected, the plant’s biological process, critical to the health and balance of the plant, is tracking in the right direction to the desired target range. This is vital to reducing and keeping odour levels at a minimum.
We continue to work closely with the plant operator Veolia, to monitor and maintain continuity of the sludge dryer service and to improve contingency planning.
Our observation of odour has shown that levels have continued to reduce in the past two weeks. We acknowledge the levels have been unacceptable and we will continue to do all we can to reduce levels. We are focused on managing the operation of the plant to minimise the risk of further equipment outages.
We are continuing work on reducing odour levels and restoring the plant to normal operations following the sludge dryer outages.
As part of regular maintenance on the sludge dryer yesterday, we identified a fault with an electrical component (variable speed drive) of one of the fans. This was replaced with a spare held on site, but it did require the dryer to be offline to enable this work to be done.
While sludge levels are still elevated, results from our daily monitoring of the plant show the treatment process is stable and this unplanned maintenance work did not have a significant impact on the plant.
We appreciate the impact of odour from the plant for residents and business. We assure you that we are working as fast as possible and doing all we can to reduce odour.
Thank you for your ongoing patience and understanding as we continue work to stabilise the health of the plant, returning it to normal operations.
We are continuing to monitor odour levels with on-site surveys in and around the plant.
The backlog of dewatered sludge is reducing, and we are continuing to transfer it to landfill. The sludge dryer operation otherwise is functioning as expected.
We want to assure the community we are doing all we can to manage odour levels. We also have an additional odour blaster on site to help.
From next week, some essential maintenance works will resume, to support the plant’s biological process.
In the meantime, we will keep the community updated on any developments and provide odour notifications as necessary.
Please note, the recent spike in odour levels is not attributable to work on the biofilter replacement upgrade. These works aim to improve the site’s overall odour control performance and minimise ongoing odour issues experienced from the site.
We sincerely apologise for the increased odour that the community has experienced over the past week. The odour levels have been unacceptable, and we regret it is taking longer than we would like to reduce levels and minimise impacts on the community.
Given the circumstances, we are working as fast as possible and doing all we can to reduce odour levels. We have suspended work on planned maintenance and upgrade activities that could contribute to additional odour levels. We are also exploring options to improve odour levels, including installing an additional odour neutraliser.
While we focus on stabilising plant operations and returning the plant to normal service, the odour levels are expected to decrease and become less noticeable. Note, this will be dependent on localised weather conditions and especially wind direction.
We will continue to engage with the community and keep them informed of any developments. We advise residents to contact the regulator, Greater Wellington Regional Council if they experience an increase in noticeable odour.
ENDS
We’re making great progress with upgrading the biofilter air distribution system at the Seaview Wastewater Treatment Plant.
Our contractors Wellington Pipelines Ltd have completed over half of the work and we’re on track to finish the works by November 1.
The biofilter upgrade is the first phase of works we’re undertaking to improve overall odour management at the plant. We’re doing these improvements on behalf of Hutt City Council and Upper Hutt City Council and they are expected to be completed in 2026.
Here are some images showing progress.
Second cell excavation
New crate plenum installation
New isolation valves in place during plenum installation
Completed cell
Work to upgrade of the biofilter air distribution system at the Seaview Wastewater Treatment Plant begins today, Monday 19 August. This is a key part of improving the management of odour at the plant. This work is expected to be completed by early November.
We advise that there may be noticeable odour coming from the plant while these works are carried out. We are managing the work to mitigate the risk and will be operating the odour neutraliser. We will be monitoring odour on site and outside the plant boundary. Find out more about the work here This is a key part of improving the management of odour at the plant. This work is expected to be completed by early November.
We advise that there may be noticeable odour coming from the plant while these works are carried out. We are managing the work to mitigate the risk and will be operating the odour neutraliser. We will be monitoring odour on site and outside the plant boundary.
Find out more about the work under 'Odour Treatment' in the menu bar.
We ask for your patience with any short-term increase in odour while we make these long-term improvements to the plant.
Thank you to members of the community, council staff and councillors, who attended a briefing on upcoming work to renew the odour control system at the plant on Tuesday 30 July.
Read the presentation delivered at the meeting here
.
The Primary Sedimentation Tank #3 (PST3) will be gradually drained from 12:00 on Wednesday 31 July 2024 in preparation for cleaning on Thursday 1 August 2024.
Please note there may be noticeable odour coming from the plant while these works are carried out. To mitigate this the Odour Suppression System/Odour Blaster will be operating and the site will be monitored.
We had 20 people attend the recent public tour of the Seaview Wastewater Treatment Plant on Saturday, June 22.
Two groups were guided through the plant following a welcome and health and safety briefing. Wellington Water’s Chief Advisor Wastewater Steve Hutchison provided a history of the plant, its construction and networks connections.
The plant operator Veolia, facilitated the walk around the plant explaining the different aspects of treatment and treatment processes. The tours ended with a Q & A session.
Invitation to Seaview Wastewater Treatment Plant Tour
Wellington Water invites you to tour the Seaview Wastewater Treatment Plant to see first-hand how the plant works and where upgrade work will be taking place.
- Saturday 22 June
- 1.30 pm to approx. 3.30 pm
- Seaview plant main entrance, Waterman Street, Seaview
- You must book in advance as numbers are limited
Please note that the tour involves walking and climbing a number of stairs so if you have mobility issues it may not be suitable for you. The tour is also not suitable for children under the age of 12.
For health and safety reasons, people must wear long pants, long-sleeved tops and closed shoes. We will provide safety equipment in the form of hard hats, hi-vis vests, safety glasses and disposable gloves, which must be worn.
Most of the tour route is outside, so jackets or rain gear may be required if it’s showery. If the weather forecast is bad, the tour will be postponed to Saturday 6 July. Numbers are limited so if there is a lot of interest we will add another date.
RSVP
Please book your place on the tour by emailing community@wellingtonwater.co.nz with your name, number of people attending, and your contact number in case of postponement. Please RSVP before Friday 14 June.
A community meeting on Thursday, 21 March discussed plant performance and Wellington Water's plans for upgrades to improve odour control.
Here is the presentation from the meeting - Seaview CLG March 21 2024
Here is the Greater Wellington Regional Council report discussed at the meeting
There were some requests for information at the meeting and these will be responded to shortly.
The works were initially expected to be completed by late January but the project team managed to reinstate the biofilter media prior to the Christmas break.
All the six cells of biofilter media are replaced and now commissioned.
Please note, While the biofilter media has been replaced, it will take a short period of time to bed in and become fully functional and 100 percent effective.
These works are a small first step to improve odour management, Hutt City Council has also included $13 million of proposed upgrades and improvements in the draft Long Term Plant.
This investment will support the long-term solution to odour management at the treatment plant.
We’ve made great progress with the biofilter media replacement at the Seaview plant.
These important works to improve odour management at the plant are ahead of schedule and we’re on track to complete the works by January 25.
From tomorrow, December 22, works will stop for the holidays and resume on January 10, 2024.
We acknowledge the patience of the local community and businesses, we look forward to completing the works for better odour management at the plant.
The team have made excellent progress after managing to replace the biofilter media in both cells 3 and 4.
This means 4 of the 6 cells of the biofilter media are replaced and commissioned.
The team have now moved to cell 5 to begin the process of excavation and inspection, before installing the new media.
Further updates will be provided as the project progresses.
Biofilter media - cells 2 &3 completed
Biofilter media - cell 4 completed
Thank you to everyone who turned up at the Seaview community meeting on Wednesday night, your attendance and views were much appreciated.
We are committed to resolving the odour issue and will be working with Hutt City Council to get the necessary upgrades prioritised.
We know you want us to keep investing in the local wastewater system. Hutt City Council will be considering odour control upgrades as part of their long-term plan meeting next Tuesday.
Hutt City Council has proposed $13 million dollars to be spent over the next 3 years on the odour control upgrade work, along with other significant upgrades for the Seaview Wastewater Treatment Plant.
The team have successfully commissioned Cells 1 and 2 today. This means that both Cells are now operational and treating the odorous gases as designed (Image 1).
The team have moved the digger into Cell 3 and commenced excavation of the old media this afternoon (Image 2). Next week Cell 3 will be excavated and inspections will be performed before installing the new media.
Further updates will be provided as the project progresses.
Image 1 - Cells 1 and 2 complete Image 2 – Cell 2 complete and digger in Cell 3
At the community meeting, Council and Wellington Water acknowledged that it's been unpleasant, inconvenient, and distressful for many who live in the vicinity, and discussed plans to address the odour issue at the Seaview wastewater treatment plant.
Te Rūnanganui o Te Āti Awa ki te Upoko o Te Ika a Māui, Waiwhetu marae and Wellington Tenths Trust/Palmerston North Māori Reserve Trust were in attendance as were many residents. The Hutt Park Holiday Village (Top 10) also attended. Deputy Mayor Lewis, Councillors Edwards, Brown, Dyer and Mike Fisher Petone Community Board Chair also attended along with staff from HCC, WW and GWRC. Seaview Marina and other businesses were also in attendance.
The presentation (815KB PDF)from Wellington Water explained the investigation undertaken to date and its outcome that biofilter media had reached the end of its lifespan and requires replacing. It was explained that an attempt to isolate and contain the first section of the biofilter as it was removed had not worked as hoped and resulted in the recent offensive odour.
Assurances were given by Council that we would do all we can to address the odour issue in the short and medium term.
Council is considering the draft Long-Term Plan, which now has a significant investment of $13 million, to significantly improve the situation with replacement of aged equipment at the plant. This investment has been brought forward to the next three years.
Mana Whenua present requested a separate briefing and for improved communications with them. Residents and businesses expressed frustration with the time it is taking to address the issue and, in the meantime, having to live with the offensive smell.
Hutt Park Holiday Village was critical the work is being undertaken during their busiest period, reporting a significant number of negative online reviews and direct complaints from customers about the smell.
Wellington Water expects this work will be completed by 25 January by which time the odour is expected to have significantly abated.
Councillors recommended that residents continue to log complaints via customer@wellingtonwater.co.nz when they notice the smell and encouraged them to make submissions to the Long-Term Plan process currently before Council. An online survey to gather feedback will appear on Hutt City Council's Annual Plans and Long Term Plans page on 2 April 2024 and remain open throughout April.
Works to replace the biofilter media are progressing well with the contractor successfully installing the new media into Cell 1 last week. (Image 1)
The digger has now been moved to Cell 2 (Image 2) and will begin removing the old media which will then be transported to landfill for disposal.
The replacement media for Cell 2 will be delivered this week and the team are optimistic of installing this ahead of schedule to fully commission cells 1 & 2 next week.
Further updates will be provided as the project progresses.
Image 1 - New media installed into Cell 1. Image 2 - Digger operating in Cell 2.