Update 6 January 2021

We won’t be updating this page while we work through how we present information about water quality monitoring for the Wellington region.

Update 29 October

Please visit the LAWA sites below for the latest recreational water quality data.

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

 

Update 13 August

South beach

Commentary on results

Recent  heavy rain (See rainfall graph below from GWRC), resulted in high values at the beach monitoring sites.

taupo stream

Of concern is the high results coming out of South Beach Access Culvert. This week was the first long period of dry weather experienced since the physical works in the catchment were completed. The results show that there are contamination issues within the catchment which is still to be identified. Although the water flowing out of the culvert is contaminated, the dry weather flow rate doesn’t appear to be significant (see image below), which suggests a localised source (or sources) of contamination rather than a larger systemic failure such as a broken wastewater main.

Importantly, sampling results from the three beach sites show minimal impact of the culvert discharge on water quality at these sites.

culvert

Public advice

The key message at the southern end of the beach is for people to avoid coming in contact with the discharge out of the culvert. This message is reinforced by the new warning sign located at the culvert mouth.

During winter heavy rain flushes contaminants from urban and rural land into waterways and it is advised that people not swim for 2 – 3 days after heavy or prolonged rain, even at sites that generally have good water quality. This includes avoiding contact with flows from stormwater drains during the same period.

Remedial works in catchment

The warning sign has been installed at the culvert mouth and will remain open displaying the warning while we continue to get poor results at the discharge stream.

signage

Following internal discussion and analysis of the data, and in consultation with Porirua City Council, Wellington Water has taken the decision to scale up the response to potential issues with public and private networks in the Titahi Bay catchment.

Hitherto, we have used an operational response framework to investigate, identify and rectify a number of acute issues with wastewater pipes in the area including breakages and cross-connections. This reactive work programme has successfully reduced the number of contamination sources affecting the quality of water exiting the South Beach Access Culvert, and has had a positive impact on sampling results.

However, the facts are that stormwater leaving the culvert remains unsafe, and the stormwater network which feeds it remains vulnerable to new or existing issues. It is not within the available resources of our operational response teams to continue addressing ongoing issues on this scale in a reactive manner.

In this context, we believe that the most effective approach to delivering a significant improvement will be via a systemic response. Internally, this means we will transfer lead responsibility for this issue from Wellington Water’s Network Management Group to our Network Engineering Team, and designate it under the resource consent conditions as a Human Health Mitigation Project.

It is very important to note that this designation does not mean that we consider that the issue constitutes an urgent or acute risk to human health in Titahi Bay. The specific risk remains most significant at the South Beach Access Culvert, hence the prominent signposting. What the Human Health Mitigation Project designation will allow us to do is apply a different level of resources and techniques towards investigating and addressing the issues in the catchment.

Two further points are important to note about this change in approach. Firstly, this catchment-scale project framework operates on a longer timescale than a reactive operational response, as it is about assessing options for major engineering-based  interventions to improve the performance of the network. Secondly, the reactive operational response remains a tool available to us, should we see further acute spikes in contamination levels in the area.

More information will be provided in future updates.

Sampling frequency

In line with the change in response, sampling will revert to our normal schedule, as the daily sampling is no longer providing us with any scientifically or operationally significant additional insight into the contamination issues. This schedule will be fortnightly at the three beach bathing sites, (until the summer months when it becomes weekly) and monthly at the culvert.

Notwithstanding this, any significant change in results at the culvert or the bathing sites, outside of what we have previously identified, will trigger more 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 Porirua Wastewater Treatment Plant.

Results table

 

Location

Sampling date

Indicator organism

Measurement (cfu/100mL)

South Beach Access Culvert

 

25/07/2020

26/07/2020

27/07/2020

28/07/2020

29/07/2020

30/07/2020

31/07/2020

01/08/2020

02/08/2020

03/08/2020

04/08/2020

05/08/2020

E.coli

 

 

22000

31000

2900

138000

120000

10400

90000

7700

3900

8640

12000

28000

Toms Road Beach

 

25/07/2020

26/07/2020

27/07/2020

28/07/2020

29/07/2020

30/07/2020

31/07/2020

01/08/2020

02/08/2020

03/08/2020

04/08/2020

05/08/2020

Enterococci

52

8

16

4

8

4

4

4

270

4

8

12

Bay Drive Beach

25/07/2020

26/07/2020

27/07/2020

28/07/2020

29/07/2020

30/07/2020

31/07/2020

01/08/2020

02/08/2020

03/08/2020

04/08/2020

05/08/2020

Enterococci

 

28

4

12

12

35

4

4

4

8

4

28

26

South Beach Access Beach

25/07/2020

26/07/2020

27/07/2020

28/07/2020

29/07/2020

30/07/2020

31/07/2020

01/08/2020

02/08/2020

03/08/2020

04/08/2020

05/08/2020

Enterococci

705

160

58

4

4

4

4

4

4

20

8

4

Update 28 July

Commentary on results

The heavy rain this week drove a significant spike in the E.coli level at the outflow from the culvert.

Public advice

During winter it is advised that heavy rain flushes contaminants from urban and rural land into waterways and that people not swim for 2 – 3 days after heavy or prolonged rain, even at sites that generally have good water quality. This includes avoiding contact with flows from stormwater drains during the same period

Latest sampling results

Location

Sampling date

Indicator organism

Measurement (cfu/100mL)

South Beach Access Culvert

15/07/2020

16/07/2020

17/07/2020

18/07/2020

19/07/2020

20/07/2020

21/07/2020

22/07/2020

23/07/2020

24/07/2020

E.coli

2000

3100

3300

5700

6900

40000

6400

3200

66000

34000

Toms Road Beach

15/07/2020

16/07/2020

17/07/2020

18/07/2020

19/07/2020

20/07/2020

21/07/2020

22/07/2020

23/07/2020

24/07/2020

Enterococci

4

4

4

4

8

4

450

38

8

4

Bay Drive Beach

15/07/2020

16/07/2020

17/07/2020

18/07/2020

19/07/2020

20/07/2020

21/07/2020

22/07/2020

23/07/2020

24/07/2020

Enterococci

4

4

4

4

4

32

200

140

12

4

South Beach Access Beach

15/07/2020

16/07/2020

17/07/2020

18/07/2020

19/07/2020

20/07/2020

21/07/2020

22/07/2020

23/07/2020

24/07/2020

Enterococci

8

4

4

4

16

44

1100

28

12

4

Titahi bay results 28 july

Remedial works in catchment

The permanent warning sign to be located at the South Beach Access culvert mouth was completed and will be erected early next week.

Proposed monitoring reversion

Wellington Water is considering reverting to our base level monitoring programme in Titahi Bay from next week. The reasons for this are:

  • Daily sampling is showing that the water quality at the culvert outflow and at the beach bathing sites is stable following the recent remedial works in the catchment
  • Stable results means continued daily sampling is no longer providing information of practical value, so the significant cost of maintaining sampling at such a high frequency is difficult to justify
  • If we revert, monitoring will be fortnightly at the three beach bathing sites, and monthly at the culvert. Any significant change in results at the culvert or the bathing sites will trigger immediate investigation
  • This regular sampling programme does not include any separate one-off sampling that may be required by resource consent conditions following an incident with the network or Porirua Wastewater Treatment Plant

If you have any views on this proposal to revert to standard regular monitoring that you would like us to consider, please reply to this email.

 

Update 5 July

We had significant amounts of rain over the week. Test results show that the water quality in the stormwater outlet at the southern end of the bay, while still impacted by the rain, has improved since the start of the year and more recently since repairs were carried out in the catchment. We continue to watch and monitor culvert water quality, as well as the three beach water quality sites.

Public advice

As per the previous update,  the permanent warning signs were closed on 22 June, and localised warning signs have been placed around the culvert stream, warning people to avoid coming in contact with the stream flow.

As heavy rain flushes contaminants from urban and rural land into waterways, it is standard public health advice that people not swim for 2 – 3 days after heavy or prolonged rain, even at sites that generally have good water quality.

 

Latest sampling results

Location

Sampling date

Indicator organism

Measurement (cfu/100mL)

South Beach Access Culvert

28/06/2020

29/06/2020

30/06/2020

01/07/2020

02/07/2020

E.coli

6900

5500

9000

554

3400

Toms Road Beach

28/06/2020

29/06/2020

30/06/2020

01/07/2020

02/07/2020

Enterococci

20

84

3400

4

69

Bay Drive Beach

28/06/2020

29/06/2020

30/06/2020

01/07/2020

02/07/2020

Enterococci

68

81

4

4

12

South Beach Access Beach

28/06/2020

29/06/2020

30/06/2020

01/07/2020

02/07/2020

Enterococci

8

460

750

4

850

 TBay 5 July

Remedial works in catchment

No other remedial work has been required since the completion of the work in May.

Thanks to the quick reporting by members of the community, our service crews remediated temporary warning signs posted at the South Beach Access Culvert that had been vandalised.

We are working with the Council to erect a permanent warning sign at the culvert mouth. This will be similar to the other four beach warning signs in that it will be able to be open or closed depending on the results of ongoing water quality monitoring.

Update 29 June

Latest sampling results

Location

Sampling date

Indicator organism

Measurement (cfu/100mL)

South Beach Access Culvert

18/06/2020

19/06/2020

20/06/2020

21/06/2020

22/06/2020

23/06/2020

24/06/2020

25/06/2020

26/06/2020

E.coli

4,600

11,100

6,500

3,900

2,600

2,000

365

4,900

1,800

Toms Road Beach

18/06/2020

19/06/2020

20/06/2020

21/06/2020

22/06/2020

23/06/2020

24/06/2020

25/06/2020

26/06/2020

Enterococci

14

140

4

4

4

4

19

12

12

Bay Drive Beach

18/06/2020

19/06/2020

20/06/2020

21/06/2020

22/06/2020

23/06/2020

24/06/2020

25/06/2020

26/06/2020

Enterococci

73

88

4

120

<4

<4

9,800

4

20

South Beach Access Beach

18/06/2020

19/06/2020

20/06/2020

21/06/2020

22/06/2020

23/06/2020

24/06/2020

25/06/2020

26/06/2020

Enterococci

120

180

12

36

4

12

8

24

12

 

Commentary on results

The results indicate a significant reduction in the E.coli levels coming out of the South Beach Access culvert over the last week. This is likely due to the remedial work completed in the stormwater catchment. There was some rainfall influence over the previous weekend which contributed to some of the higher results. The above column graph shows sampling results for the culvert going back to March of this year.

We believe the single high results for the Bay Dr site on 24/06 and the culvert site result on 25/06 were likely also linked to rainfall at the end of the week. Since then, the sites have settled down with Bay Dr being well within recreational bathing requirements.

 

Public advice

Wellington Water has looked at the new daily results, and combined with the physical works undertaken below, we are confident that the discharge on to the beach from the culvert is not having an adverse impact on the recreational bathing sites. Consequently, the permanent warning signs were closed on Tuesday. However localised warning signs have been placed around the culvert stream, warning people to avoid coming in contact with the stream flow.

 

Remedial works in catchment

The current works were completed on Monday. No other physical works were undertaken in the past week.

Daily sampling and testing will continue until further notice.

 

Update 24 June

Following positive progress on repairs to the collapsed wastewater main which has been affecting water quality at the South Beach access culvert, as well as consistently good daily water quality test results at multiple beach sampling sites, we’ve closed the warning signs on the beach. 

We understand this has been a real frustration for the community, and we thank you for your patience during the time it has taken to reach this point.

There is still work to be done to find and fix faults (public and private) within the catchment to improve water quality in the stream and culvert. For that reason, warnings will remain in place near the culvert at the beach, and we advise that you don’t come into contact with the flow out of the culvert onto the beach. However the lab results are indicating that the culvert has a negligible effect on the water quality along the beach itself.

Update 21 June

Latest sampling results:

Location

Sampling date

Indicator organism

Measurement (cfu/100mL)

South Beach Access Culvert

12/06/2020

13/06/2020

14/06/2020

15/06/2020

16/06/2020

17/06/2020

E.coli

727

12,200

2,100

13,800

8,600

2,900

Toms Road Beach

12/06/2020

13/06/2020

14/06/2020

15/06/2020

16/06/2020

17/06/2020

Enterococci

24

<4

<4

<4

<4

8

Bay Drive Beach

12/06/2020

13/06/2020

14/06/2020

15/06/2020

16/06/2020

17/06/2020

Enterococci

8

19

16

4

4

4

South Beach Access Beach

12/06/2020

13/06/2020

14/06/2020

15/06/2020

16/06/2020

17/06/2020

Enterococci

12

360

340

<4

<4

<4

Commentary on results

The results indicate ongoing wastewater dry weather contamination out of the stormwater culvert at the South Beach Access. However the beach monitoring sites are showing that this is having minimal impact on the beach itself at those sites.

Public advice

Looking at the new daily results, combined with the physical works undertaken below, we’re confident that the discharge onto the beach from the culvert is not having an adverse impact on the recreational bathing sites. Consequently, we expect to be closing the warning signs at Titahi Bay beach next week, after 48hrs of clear weather.

The warning signs remain in place for now only because of general public health advice to avoid swimming and other recreational activity at bathing sites near stormwater outlets following heavy or prolonged rainfall.

Localised warning signs will be placed near the culvert stream, warning people to avoid coming in contact with the stream flow.

Remedial works in catchment

The issues with all three private wastewater lateral pipelines referred to in last week’s update have now been fixed.  Work on the collapsed wastewater main began as scheduled this week, but was delayed because of the wet weather.

Next scheduled sampling dates

Daily sampling and testing will continue until further notice.

Update 12 June

Latest sampling results

Location

Sampling date

Indicator organism

Measurement

South Beach Access Culvert

11/06/2020

E.coli

3,300cfu/100mL

Commentary on results

The results indicate ongoing wastewater dry weather contamination out of the stormwater culvert at the South Beach Access.

Public advice

We are moving to a daily sampling programme at the recreational bathing (Baywatch) sites and at the outlet of South Beach Access culvert. We can’t maintain this indefinitely with our current resources, but what we do now will help us understand whether tidal influences are bringing contamination from the culvert back on to the beach. This will help us review the need for warning signs advising against bathing and other recreational activity at those sites. We expect the daily sampling data will have given us a clearer understanding by the end of next week; until that time the warning signs will remain up.

Remedial works in catchment

To date, we’ve identified three private broken lateral connections using dye testing and CCTV that would be contributing to the current high counts. One lateral has been repaired and we’ve been in further contact with the residents at the other two properties in the catchment. The residents have been cooperative and we are working with them to accelerate repairs.

We also expect repairs to be complete by next week of a cracked and dipping section of publicly-owned wastewater main running beneath private property within the catchment further up.

While all these repairs are positive progress, it is important to note that the Titahi Bay catchment is very large, and it is unlikely that the faults we have identified are the only ones contributing to the contamination of the stream and South Beach Access culvert. Wellington Water’s ‘roving crews’ initiative, approved for funding by Porirua City Council in their draft Long Term Plan, would allow us to maintain ongoing investigations into public and private network faults, and remediate them as they are identified. This is a part of a long-term effort to address water quality in the area, which will involve ongoing collaboration between the community, Council, Wellington Water and other stakeholders.

Next scheduled sampling dates

Week commencing 14 June.

Titahi Bay water quality monitoring community update

Wellington Water monitors environmental water quality to detect acute contamination spikes which may indicate problems within the network. This update is to inform the community of current activity in the area, and is a snapshot overview, not a comprehensive report on the overall condition of the waterways.

All samples are gathered and analysed by an independent specialist laboratory.

Latest sampling results

Location

Sampling date

Indicator organism

Measurement

South Beach Access Culvert

19/05/2020

E.coli

35,200cfu/100mL

Titahi Bay recreational bathing site at Toms Dr

03/05/2020

Enterococci

12cfu/100mL

Titahi Bay recreational bathing site at South Beach Access

03/06/2020

Enterococci

8cfu/100mL

Titahi Bay recreational bathing site at Bay Dr

03/06/2020     

Enterococci

<4cfu/100mL

Commentary on results

The results indicate ongoing dry weather contamination of the stormwater culvert at the South Beach Access. However the beach monitoring sites are showing that this is having minimal impact on the beach itself at those sites.

Public advice

Wellington Water recommends that the warning signs remain open as there is a risk that an incoming tide could bring the culvert contamination back onto the beach.

Remedial works in catchment

As per last week’s update, our team has discovered a 9m long collapsed section of a wastewater pipe that was overflowing into the stormwater system. Although it is a Porirua City Council pipe, it is located on private property. Due to its location, we investigating the option of relining the pipe to try and reduce the impact on the residents (as compared to substantial earthworks on their land).

Our team also located a plumbing fault at another property that meant domestic waste was flowing into the stormwater system. This was brought to the attention of the property owner and they have since repaired it.

A third site also has a possible private plumbing fault, however investigating this has been hampered by wet weather compromising flow through the stormwater pipe. The investigation will resume when weather allows.

Sampling and testing continues and the warning signs will stay out while the remediation work continues.

Next scheduled sampling dates

Week commencing 14 June

Map of sampling locations

Titahi Bay sampling