Seaview Wastewater Treatment Plant Newsletter May 31, 2024 

Your latest news on what's happening at the Seaview Wastewater Treatment Plant

Kia ora koutou Welcome to the regular monthly update about Wellington Water’s operation of the Seaview Wastewater Treatment Plant and the programme of upgrade work.   You are 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 ·    Invitation to tour plant on Saturday, June 22 ·    Odour Treatment Renewal Project update ·      Plant performance update ·      Odour neutraliser product ·      Public health signs ·      What’s next ·      Get in touch _______________________________________ Invitation to tour plant 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, June 22 1.30pm to approx. 3.30 pm Seaview plant main entrance, Waterman Street, Seaview You must book in advance as numbers are limited Please note 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 June 14.

Odour Treatment Renewal Project update We are on track with design and planning for the next stage of work on the biofilter this winter.  Our consultant Beca developed the detailed design for improvements to the biofilter air distribution system (plenum) and biofilter cell isolation system. The design is now being peer-reviewed by Stantec. Another work package is to repair leaks in the odour ducts running outside the buildings, which carry air to the biofilter for treatment. We expect to shortly receive a report summarising the external ducting condition assessment, which will inform the next steps. Design work is progressing for the milliscreening ducts and fans work package and the building odour treatment work package.

Plant Performance update We are continuing efforts to improve the operation of the biological process and the ultra-violet (UV) disinfection system, but unfortunately the plant is still not compliant with one of three standards for treated wastewater discharged into Cook Strait. You can find the April monthly performance dashboard here . 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. Our goal is to return to compliance as soon as possible.  There were two discharges in April. On 7 April, at the Pencarrow outfall, there was a release of undisinfected wastewater due to a power outage. On 12 April, there was a discharge of fully treated wastewater to the Waiwhetū Stream due to wet weather events. Overall, the plant received 35 odour complaints in April.   Wellington Water is launching a review into the region’s metropolitan wastewater treatment plants. The purpose of this review is to assess why the plants are still having issues meeting resource consents and to identify any immediate improvements to current operating models. We acknowledge there are challenges with treatment plant assets and their current condition. These ageing assets are a key contributor to the non-compliance with resource consents. Most of the risks are currently being addressed through work to renew the assets. This will take time, as the work must be done while the plants are running and within the available council budget. ________________________________ Odour neutraliser product  An odour neutraliser is sprayed at times within the Seaview plant boundary. The plant operator, Veolia, recently switched to a new product Odour Neutraliser Plus (SCD1100) which is manufactured by biOx Environmental. This is a stabilised chlorine dioxide product that oxidises odour molecules such as Hydrogen Sulfide. The product is safe when used as directed and is utilised in wastewater treatment plants, landfills and transfer stations throughout New Zealand. An independent assessment (available here) shows that, while Odour Neutraliser Plus in its undiluted form is a hazardous substance, when it is diluted for use it falls below hazard classification thresholds; that is, the risk is low. At the Seaview plant, it is diluted at 500 parts water to 1 part chemical. The previous product was called Hi Chem Disinfectant Reodorant. While we had advice from Public Health that this product was safe, we have listened to complaints from the community about the odour it generates and have stopped using it. An action point from the March public meeting was to provide the amount of neutraliser odour spray used on a weekly basis.  Veolia uses an average of 12.5 litres per week of undiluted odour neutraliser product.

Public health signs At the community meeting in March, there was discussion about the public health warning signs that are displayed when there is an overflow of treated wastewater into the Waiwhetū Stream, and whether there should be signage targeted at people fishing off the Waione Street Bridge.

There are currently two folding signs in locations specified in the resource consent at the Seaview Road Bridge (next to Urupa) and Port Road Bridge, (highlighted in orange).  These signs are unfolded, or opened, to show a public health warning as soon as practical after an overflow. On the map, the treatment plant discharge point is shown (red arrow) and is downstream from the bridge. For longer-term discharges during maintenance or repairs on the Main Outfall Pipeline, two folding signs at Seaview Marina and Marine Parade are also used (in red). In addition, there are temporary signs near any location in Eastern Bays which are used to drain the section of the pipeline being worked on.  We are aware of, and understand concerns regarding wastewater discharges, especially where there is a potential impact on mahinga kai, fishing or gathering shellfish. We are looking at how we can better manage these occasional discharges into the Waiwhetū Stream. In the meantime, however, we are assured the health risk to people fishing off the bridge is relatively low, for the following reasons;  The discharge point is downstream of the bridge with no affect on the full width of the river  Fish will avoid the discharge due to the presence of ammonia in the treated wastewater.  We have now completed the action point from the March public meeting, of reviewing the signage. We can confirm the current signage meets the requirements set out in the current resource consent. We have discussed this with Greater Wellington Regional Council and Hutt City Council and are awaiting further feedback.  Port Road Bridge sign

Next month ·     Peer review of the designs for the biofilter works will be completed   ·     Procurement of contractors and equipment for biofilter works to be confirmed ·     Notifications of odour issues and overflows

Get in touch Book your place on 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 relating to this newsletter, email community@wellingtonwater.co.nz. For 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

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

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