We are currently working on how we present information about water quality monitoring for the Wellington region.

Sampling

From the 31 March 2021, this schedule will be fortnightly and only at Toms Beach Road.

Any significant change in results will trigger a detailed investigation. The regular sampling programme may be supplemented by one-off sampling in accordance with resource consent conditions, should we experience an incident with the network or the Porirua Wastewater Treatment Plant.

Titahi Bay Sampling August 2020 - October 2021

*Results from 23 March 2021 are in relation to the UV outage at the Porirua Wastewater Treatment Plant. These results show that the number of bacteria present were within the bathing beach guidelines and presented a low risk to human health. 

Dry weather recreational testing standards:

  • Green: <140
  • Amber alert: 140> (re-test)
  • Red alert: 280> (re-test, open signs and public warnings) 

For more information on our tests, what we test for and how we do it, click here.

Network status

This reporting was stopped on the 31 March 2021. For further information on the network, please check the work in your area map.

Date

Status

Notes

31 March 2021

Green

No jobs reported.

30 March 2021

Green

No jobs reported.

29 March 2021

Green

No jobs reported.

28 March 2021

Green

No jobs reported.

27 March 2021

Green

No jobs reported.

26 March 2021

Green

No jobs reported.

25 March 2021

Green

No jobs reported.

24 March 2021

Green

No jobs reported.

23 March 2021

Green

No jobs reported. 

22 March 2021

Green

No jobs reported. 

21 March 2021

 Orange4

1 job reported - an overflow caused by a blockage in a private pipe,
 e.g. someone flushed a large amount of toilet paper.  

20 March 2021

Green

No jobs reported.

19 March 2021

Green

No jobs reported.

18 March 2021

 Orange4

Yesterday evening the Wellington Water team
was called out to a wastewater overflow near
South Beach Access Road in Titahi Bay.

They worked fast and were able to prevent
any wastewater going into the beach, but
what they did discover was a… fatberg!
For more information on what a fatberg is, go here.

17 March 2021

Green

No jobs reported.

16 March 2021

Green

No jobs reported.

15 March 2021

Green

No jobs reported.

14 March 2021

Green

No jobs reported.

13 March 2021

Green

No jobs reported.

12 March 2021

Green

No jobs reported.

11 March 2021

Green

1 standard job fixed.

No negative impact on water quality.

10 March 2021

Green

No jobs reported.

 9 March 2021

Green

A drainage crew inspected the Titahi Bay South Beach drains
following a customer complaint. Samples were taken, there
was no smell or wastewater found. No overflow.

 8 March 2021

Green

No jobs reported.

 7 March 2021

Green

No jobs reported.

 6 March 2021

Green

No jobs reported.


 5 March 2021

Green

No jobs reported.

 4 March 2021

Green

No jobs reported.

 3 March 2021

 Orange4

1 (private) wastewater blockage.

Some wastewater seepage onto footpath.

 2 March 2021

Green

No jobs reported.

 1 March 2021

Green

No jobs reported.

 18-25 February 2021

Green

2 standard jobs fixed.

No negative impact on water quality.

 11-18 February 2021

Green

2 standard jobs fixed.

No negative impact on water quality.

Treatment plant status

This reporting was stopped on the 31 March 2021. If you would like to be added to Porirua Wastewater Treatment Plant interested parties list, you can email us on customer@wellingtonwater.co.nz

Date

Status

Notes

31 March 2021

Green

 No incidents reported

30 March 2021

Green

 No incidents reported

29 March 2021

Green

 No incidents reported

28 March 2021

Green

 No incidents reported

27 March 2021

Green

 No incidents reported

26 March 2021

Green

 No incidents reported

25 March 2021

Green

 No incidents reported

24 March 2021

Green

 No incidents reported

23 March 2021

 Orange4

This morning we identified that the ultra-violet (UV) treatment equipment
was not running at the Porirua Wastewater Treatment Plant. It was reactivated
as soon as it was discovered; however, it had been off since 3pm yesterday.

The risk to health from this bypass is very small, as the tidal current will dilute
and disperse the un-UV-treated wastewater. We have done some shoreline
monitoring and have shared the results on our website below.

Ultra-violet (UV) light disinfection is the final stage in treating wastewater.
The treatment process removes solids most of the harmful bacteria before
it gets to the UV stage. UV disinfection destroys remaining bacteria and viruses
before it is discharged to the sea.

We are treating this extremely seriously, particularly given the lessons learnt
after the incident in January. We sincerely apologise that this has occurred and
will do everything we can to prevent it happening again.

22 March 2021

Green

 No incidents reported

21 March 2021

Green

 No incidents reported

20 March 2021

Green

 No incidents reported

19 March 2021

Green

 No incidents reported

18 March 2021

Green

 No incidents reported

17 March 2021

Green

 No incidents reported

16 March 2021

Green

 No incidents reported

15 March 2021

Green

 No incidents reported

14 March 2021

Green

 No incidents reported

13 March 2021

Green

 No incidents reported

12 March 2021

Green

 No incidents reported

11 March 2021

Green

 No incidents reported

10 March 2021

Green

 No incidents reported

 9 March 2021

Green

 No incidents reported

 8 March 2021

Green

 No incidents reported

 7 March 2021

Green

 No incidents reported

 6 March 2021

Green

 No incidents reported

 5 March 2021

Green

 No incidents reported

 4 March 2021 

Green

 No incidents reported

 3 March 2021 

Green

 No incidents reported

 2 March 2021  

Green

 No incidents reported

 1 March 2021

Green

 No incidents reported

 18-25 February 2021

Green

 No incidents reported

  11-18 February 2021

Green

 No incidents reported

 

Is it safe to swim?

To find out the current status of Titahi Bay for swimming please visit the Land Air Water Aotearoa (LAWA) website for:

Notices

We’re upgrading the Porirua Wastewater Treatment Plant.  Find out about work planned here – and rest assured that we’re taking steps to minimise any risk to public health.  

Release of undisinfected wastewater - March 2021

Action is being taken to improve systems at the Porirua Wastewater Treatment Plant, following an incident investigation into a discharge of undisinfected wastewater in late March.

What happened:

On the morning of 23 March, an employee at the Titahi Bay Wastewater Treatment Plant discovered, during routine maintenance rounds, that the ultra-violet (UV) treatment equipment was turned off. It was reinstated as soon as it was discovered; however, it was established that the UV treatment had been off since 3pm Monday 22 March – 18 hours.

The ultra-violet (UV) treatment equipment had been turned off to perform routine maintenance on a blocked reclaimed effluent (RE) pump, used to disperse treated water for cleaning purposes.

To perform this maintenance, the ultra-violet (UV) treatment equipment needed to be stopped and partially drained for 30 minutes, before being reinstated. The UV system automatically shuts down when the channel level drops below a set level, as the UV lamps must be submerged while in operation.

Once the RE pump was out of the channel, the site operators began re-filling the UV channel before leaving the site.

A fault occurred with the controls on the outlet weir - after the UV stage. The weir controls the level of the UV channel. The weir will drop down to the lowest position if a fault occurs. This meant that the UV channel didn’t refill.

This caused the UV system to be bypassed and undisinfected wastewater to be discharged.

An alarm was activated. The operators acknowledged the alarm since they assumed the UV system was still filling. The alarm remained active in the system. The operator also did not perform the scheduled check at 4pm and only partially reviewed the site at 8pm. This resulted in the UV fault being missed.

When the fault was discovered, repairs were made to the controls on the outlet weir. The wastewater level in the channel increased and the UV system was able to resume operation.

Notifications were submitted to interested parties list, the shoreline monitoring campaign was started, and an investigation was conducted regarding this incident.

Measures undertaken to prevent this happening again:

  • Wellington Water are committed to a robust review of what happened to improve future performance for our community, our mana whenua partners and our clients.
  • A disciplinary investigation as well as additional checks and reviews will be performed by our operator’s management team to ensure that tasks are being performed as expected.
  • A review of the critical alarms at the WWTP has been completed. This has significantly reduced the amount of nuisance alarms being sent after hours. A review of the local alarms is now being done to remove further nuisance alarms. This should be completed by August 2021.
  • The alarm escalation process is also being reviewed and our operator will propose any modifications to prevent alarms from being missed.
  • Wellington Water are currently upgrading the Porirua Wastewater Treatment plant, including installing new ultra-violet (UV) equipment. This will provide redundancy and mean that future maintenance of the UV system will not require any partially treated wastewater to be discharged.
  • The upgrade to the UV equipment is part of a multi-million-dollar upgrade to the plant that will be completed by 2023. Find out more here: wellingtonwater.co.nz/pwp

Background

Wastewater that has not been through UV disinfection is formally described as ‘partially-treated’ but a better description would be ‘almost-fully-treated’. The treatment process removes solids and most of the harmful bacteria before it gets to the UV stage. UV disinfection then further reduces the concentration of bacteria and viruses. 

In general, a discharge of undisinfected wastewater would not be expected to significantly increase the health risk to recreational water users.

Report

To read the incident report, please click here