This document was approved by GWRC *-----TBA----- * 2015.
It supersedes all previous management plans for the project.
A copy of this document must be supplied to all parties working on the pipeline, and available on site at all times.
WCC’s Western Wellington Wastewater Treatment Plant (WWTP) Main Outfall Pipeline (Karori Stream to Makara Coast)
Management & Monitoring
Plan
Prepared for: Wellington Water On behalf of Wellington City Council
October 2015
Cardno Ref: NZ01-14121 Wellington Water Ref: PO 0000008830
Karori Main Outfall Pipeline Management & Monitoring Plan
Contact Information Document Information
Cardno Limited Prepared for Wellington City Council Trading as Cardno (NZ) Limited Project Name Management & Company No: 036749 Monitoring Plan
File Reference NZ0114121-PL- (Wellington / Head Office) Management & 25 Victoria Street, Petone, Lower Hutt 5012 Monitoring Plan-Karori
MOP-FINAL 5 Oct 15-v5 PO Box 38-098, Wellington Mail Centre, Petone I.docx Lower Hutt 5045, New Zealand Project Reference NZ0114121 Telephone: (04) 478-0342 Date October 2015 [email protected] www.cardno.com
Document Control
Date Description Author Author Reviewer Initials (Signature) Version 1 08/08/2014 Draft Management Plan for Client Comment JKG 1A 21/08/2014 Draft following comment for client approval JKG 1B 09/09/2014 As above – additional client input added JKG 1C 3/10/2014 Final Draft for Submission to GWRC with final JKG client comments added 1D 22/10/2014 Final amendments as agreed with client JKG Anna Hector following additional client input 1E 25/06/2015 Final Draft for GWRC Consultation – allowed JKG Anna for fish rescue methodology to be appended. Hector/GWRC 1F 16/08/15 Final Draft (v3) for DOC Consultation (report JKG Anna Hector dates amended) 1G 24/08/15 Final Draft (v4) for landowner Consultation JKG Anna Hector (report date amended) 1H 05/10/15 Final (v5) Removed draft comments – for JKG Anna Hector lodgement.
Key Abbreviations used in this MMP GWRC Greater Wellington Regional Council MOP Main Outfall Pipeline MMP Management & Monitoring Plan WCC Wellington City Council WWTP Wellington City Council’s Western Wastewater Treatment Plant
© Cardno 2012. Copyright in the whole and every part of this document belongs to Cardno and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person other than by agreement with Cardno. This document is produced by Cardno solely for the benefit and use by the client in accordance with the terms of the engagement. Cardno does not and shall not assume any responsibility or liability whatsoever to any third party arising out of any use or reliance by any third party on the content of this document.
October 2015 i Karori Main Outfall Pipeline Management & Monitoring Plan
QUICK REFERENCE SUMMARY
This Management & Monitoring Plan (MMP) supports a 2014 application by Wellington City Council for New “Global” Resource Consents to enable Wellington Water (or their representatives) to undertake (on behalf of Wellington City Council, WCC) a range of planned and unplanned maintenance and repairs along the Main Outfall Pipeline (MOP) from WCC’s Western Wastewater Treatment Plant (WWTP) to the Ocean Outfall on Wellington’s South Coast.
The MMP also covers the requirements of the WWTP Discharge Permit WGN060283 [25226] relating to inspection and maintenance of the integrity of the wastewater pipeline until it is replaced (replacement is required to have occurred by 31 December 2023). Condition 22 of the consent requires the MOP to be managed and monitored to avoid, remedy and mitigate adverse effects of treated wastewater discharges to the Karori Stream associated with leaks or failures of the aging pipeline. Condition 23 requires annual reporting on the MOP covering inspections, observations, repairs and planned remedial activities over the previous year.
This MMP supersedes all previously prepared MMP documents submitted to Greater Wellington Regional Council (GWRC) for approval. It has been prepared in a format that enables it to be referenced in conditions of resource consent and to be used as the stand alone document for administration, monitoring and compliance purposes.
The information contained within this MMP is intended to meet the requirements of GWRC, and has been prepared with reference to GWRC’s “Erosion and Sediment Control Guidelines for the Wellington Region (September 2002) and other related documents (including existing consents), referenced later.
This MMP must be read and implemented as part of any contract documentation prior to commencement of earthworks on the site.
Emphasis is placed on the avoidance, mitigation or remediation of potential adverse effects on surrounding properties and the aquatic habitat values of the Karori Stream as a direct result of any maintenance and repair works.
As the Karori Stream environment is dynamic and conditions are constantly changing, the proposed works have been described as a series of possible scenarios to suit the typical conditions in the different parts of the stream along the length of the pipeline. However, variations to the proposed methodologies may be required on a case by case basis to maintain protection of downstream environments (e.g. from sediment released by stream bed disturbance) while also working within local site constraints.
Any changes to this MMP must be submitted for approval to GWRC and written approval obtained in advance of actions made on site. The approved variations shall be appended to this document as a permanent record.
Advisory Note: This MMP document brings together all relevant information required to support the monitoring and management requirements of Condition 22 of WGN060283 [25226] and address relevant environmental effects to the required acceptable standard under the Regional Freshwater Plan for the Wellington Region. This MMP supersedes all previous advice and information and all previously approved documents. It does not cover any other monitoring.
Copies of the relevant resource consents are to be included in the contract documents.
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TABLE OF CONTENTS
1. INTRODUCTION & SCOPE OF DOCUMENT ...... 5 1.1 Compliance and Amendments ...... 6 1.2 Reference Documents ...... 6 1.3 Legal Descriptions of Land Accessed for Pipeline Maintenance ...... 6
2. REGIONAL PLAN & RESOURCE CONSENT REQUIREMENTS ...... 7 2.1 WGN060283 [25226] Condition 22 ...... 7 2.2 WGN060283 [25226] Condition 23 ...... 8 2.3 Requirements of Other Consent Conditions ...... 8 2.4 Repairs to Date ...... 8 2.5 New Consents Required to Undertaken Repairs & Maintenance ...... 9 2.6 Works within Sensitive Catchments ...... 9 2.7 Limitations to Monitoring covered in this MMP ...... 9
3. LOCATION & ACCESS INFORMATION ...... 10
4. THE MAIN OUTFALL PIPELINE (MOP) ...... 12
5. INSPECTIONS ...... 17 5.1 Consent Requirements ...... 17 5.2 Frequency of Pipeline Inspections ...... 17 5.3 Procedures for Inspections ...... 18 5.3.1 All Inspections ...... 18 5.3.2 Event Based Inspections ...... 18 5.3.3 Annual Inspections ...... 19 5.4 Procedures for Identifying & Recording Faults in the Pipeline ...... 19 5.5 Procedure for Flow Monitor Data Capture ...... 23 5.5.1 In the Office ...... 23 5.6 Sampling & Assessment Procedure ...... 24 5.6.1 Testing for Suspected Pipeline Leaks ...... 24 5.6.2 Sampling Technique ...... 24 5.6.3 Sample Storage & Transfer to Laboratory ...... 24 5.6.4 Sample Assessment ...... 25 5.7 Follow-Up ...... 25
6. MAINTENANCE AND REPAIRS ...... 27 6.1 Consent Requirements ...... 27 6.2 Responsibilities of Contracts Officer ...... 27 6.3 Responsibilities for All Maintenance & Repair Work ...... 28 6.4 Overview of Typical In-Stream Maintenance & Repair Works ...... 28 6.5 Vegetation Clearance ...... 29 6.6 Acceptable Methods of Repair for Pipeline Leaks ...... 29 6.7 Types of In-Stream Works Anticipated for Repairs and Maintenance ...... 30 6.7.1 Clearance of Flood or Slip Debris ...... 30 6.7.2 Deposition of Gravel ...... 31
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6.7.3 Construction of Temporary Access Platforms ...... 32 6.7.4 Re-Grading of Existing Fords ...... 33 6.8 Works Methodologies & Mitigation Measures ...... 33 6.8.1 Diversions (Temporary and Permanent) & Works in Active Flowing Sections of Stream ...... 33 6.8.2 Erosion and Sediment Controls ...... 35 6.8.3 Other Contaminant Controls ...... 35 6.8.4 Fish Passage ...... 36
7. MONITORING & REPORTING ...... 37 7.1 Consent Requirements ...... 37 7.2 Annual Reporting ...... 37
8. GENERAL MANAGEMENT ...... 38 8.1 Health and Safety Provisions ...... 38 8.1.1 General ...... 38 8.1.2 Inspections ...... 38 8.1.3 Maintenance & Repair Work ...... 38 8.2 Equipment Requirements ...... 39 8.3 Discovery of Artefacts ...... 40 8.4 Cartage of Materials and Machinery ...... 40 8.5 Vegetation Removal, Storage & Disposal ...... 40 8.6 Weather Forecasts ...... 41 8.7 Monitoring, Plan Review and Amendments ...... 41 8.8 Register of Public Complaints/Incidents and Reporting Procedures ...... 41
9. CONSULTATION ...... 42 9.1 Consent Requirements ...... 42 9.2 Procedures for Notifying Landowners and GWRC and Others ...... 42 9.2.1 Landowners ...... 42 9.2.2 GWRC ...... 42 9.2.3 Others ...... 43
10. CONTACT PERSONNEL AND RESPONSIBILITIES ...... 44
LIST OF APPENDICES
APPENDIX A: PLANS OF PIPELINE (including enlargement of Figure 2) APPENDIX B: COPY OF RELEVANT RESOURCE CONSENTS APPENDIX C: HAZARD IDENTIFICATION RECORD SHEET APPENDIX D: DEFECT RECORD FORM APPENDIX E: FISH RESCUE METHODOLOGY APPENDIX F: RECORD OF APPROVED AMENDMENTS TO MMP
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1. INTRODUCTION & SCOPE OF DOCUMENT This Management & Monitoring Plan (MMP) describes the inspection process and methodologies of typical planned and unplanned maintenance and repair works required to ensure the ongoing integrity of the WWTP Main Outfall Pipeline (MOP) until it is replaced (this is required to have occurred by December 2023).
It includes:
• Details required by GWRC under conditions 22 and 23 of a resource consent issued in 2010 for the discharge of treated wastewater from WCC’s Western Wastewater Treatment Plant (WWTP) via the MOP following the Karori Stream to the Coastal Outfall on Wellington’s South Coast (Reference: Discharge Permit WGN060283 [25226]); and
• Information to support the 2014 application by WCC for additional consents for maintenance and repair works on the MOP (including clearance of gravels and debris, deposition of gravel, river crossings, construction of access platforms, repair of access fords, disturbance of stream bed material, and deposition of new material on the stream bed and diversions of stream flows) and
• A framework covering reporting requirements and responsibilities to assist with consultation, implementation, monitoring and consent compliance processes.
Key features of this MMP are:
• Avoiding, remedying and mitigating the risks and/or effects of pipeline leaks and failures which have the potential to discharge treated wastewater effluent to the Karori Stream;
• Methodologies for the various maintenance and repair works processes to minimise release of sediment to the Karori Stream during the works and the potential adverse impacts on the habitats of native fish species that have been previously observed in the Karori Stream and its tributaries;
• Methods to avoid or address erosion and scour effects as a result of maintenance and repair works; and.
• Consultation with stakeholders regarding access to the works areas and the works programmes.
The overall focus of the MMP is maintenance and protection of the receiving environment (water quality and freshwater aquatic habitat of native fish species) while also ensuring the inspections, maintenance and repair processes do not adversely impact landowners’ ability to utilise their properties for lawfully established activities.
Emphasis is placed on avoidance, remedy or mitigation of potential adverse environmental effects as a direct result of works described in this MMP, in particular prevention of sediment release to the Karori Stream or loss of freshwater aquatic habitat. This is primarily achieved by ensuring planned works occur in the dry as much as practicable or at times outside the known migration and spawning seasons.
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1.1 Compliance and Amendments
This MMP should be read and implemented in full compliance as part of any contract documentation and conditions of the relevant resource consents issued by Greater Wellington Regional Council to the satisfaction of GWRC officers. Relevant resource consents must be included as part of any contract documents.
Any amendments that need to be made to any part of this MMP require prior approval in writing from GWRC before implementation, and details of the approved changes must be recorded at Appendix F.
1.2 Reference Documents
Relevant Supporting & Reference Documents are:
• Wellington Regional Council – “Erosion and Sediment Control Guidelines for the Wellington Region” (September 2002). “The Guidelines”;
• Plans of MOP (Appendix A) which can be referred to in conjunction with images and descriptions in this MMP;
• Greater Wellington Regional Council Resource Consents referenced WGN060283 [25226], specifically Conditions 22 and 23 quoted at Section 2, and Global Consent WGN14*** [**to be advised once approved***] (at Appendix B);
• Hazard Identification Form (Appendix C); • Defect Record Form (Appendix D); • Fish Rescue Methodology (Appendix E);
• Record of any changes to this MMP approved by GWRC (Appendix F).
1.3 Legal Descriptions of Land Accessed for Pipeline Maintenance
Summary ownership details for land required for access and maintenance are set out below (refer consultation and reporting processes at Section 10 of this Document):
Registered Land Owner Legal Description Address
Wellington City Council Section 1 SO 37211 South Karori Road
Erin Go Bragh Limited Lots 2 & 3 DP 422854 509 South Makara Road
CS & PA Griffiths Lot 2 DP 414390 555, 567 South Makara Rd
NZ Forestry Group Limited * Lots 1, 16 & 20 DP 414390, 588 South Makara Road (Kinnoull Station) Lots 3-12 DP 425554, Lots 13 & 4 DP 366070
Terawhiti Farming Company Secs 4 & 17 & Pt Secs 13, 14, 1079 South Makara Road Limited 15, 19, 33 & 50 Terawhiti District, Lot 3 DP 5864.
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2. REGIONAL PLAN & RESOURCE CONSENT REQUIREMENTS Because of the age and potentially deteriorating state of the WWTP MOP, it has been programmed for replacement in 2023. In the meantime, consent conditions 22 and 23 of WWTP Discharge Permit WGN060283 [25226] require the pipeline to be regularly inspected, maintained and repaired, with annual reporting and 9-10 yearly reviews.
This MMP has been prepared in response to these requirements. Key consent conditions 22 and 23 are set out below, followed by additional requirements of existing consent conditions 5, 20 and 21, and a summary report of major repairs to date.
The rest of the MMP focuses on inspections and maintenance and repair works methods to ensure protection of the Karori Stream water quality and freshwater aquatic habitat values from discharge of sediment and disturbance of the stream bed during those works activities.
2.1 WGN060283 [25226] Condition 22
Condition 22 is as follows:
“The permit holder shall prepare a management and monitoring plan for the outfall pipeline within three months of the commencement of this permit. This plan shall include, but not be limited to:
a) The procedures for pipeline inspections (including frequency, personnel, access arrangements, vegetation clearance, methodology);
b) The procedures to be used for identifying faults in the pipeline (such as indicators that the pipeline or part of the pipeline may require repair or replacement);
c) The procedures to be followed when undertaking repair or replacement works on the pipeline; and d) A requirement to undertake an annual review of the condition of the pipeline;
The management and monitoring plan shall specify an approach and the factors to be taken into account in this review (such as how the information will be reviewed in the context of the permit holder’s asset management procedures, taking into account matters such as location of faults, nature of faults, condition of the pipeline, and expenditure).
e) Procedures for notifying the landowners and Wellington Regional Council of leaks and the nature and timing of repair works.
The permit holder shall submit the plan to the Manager, Environmental Regulation for approval within 3 months of the commencement of this permit for the purposes of ensuring that it contains the information required by this condition, and that it includes the following commitments:
f) Inspections will be undertaken at least every 3 months; and
g) Any leaks detected will be repaired as soon as practicable.
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The management and monitoring plan shall be implemented as soon as it has been
approved by the Manager, Environmental Regulation, Wellington Regional Council.
Following its approval, the management and monitoring plan is to be reviewed and updated once every five years by the permit holder, to the satisfaction of the Manager, Environmental Regulation, Wellington Regional Council.
2.2 WGN060283 [25226] Condition 23
Condition 23 is as follows:
“The permit holder shall submit an annual report for the main outfall pipeline, which addresses activities undertaken during the previous year, to the Manager, Environmental Regulation, Wellington Regional Council and members of the CLG, by 31 July each year.
This report shall include, but not be limited to, the following elements:
a) Details of the location, extent and duration of any leakage or faults, and the timing, nature and success of remedial action taken to remedy the leaks or faults;
b) Details of any other works (including any repairs and replacements) undertaken during the past year; and
c) Any work planned in the next 12 months to repair or replace the pipeline”.
2.3 Requirements of Other Consent Conditions
The MMP also needs to cover the separate reporting requirements in the conditions of the resource consent for discharge from the WWTP. The requirements are paraphrased as follows (with relevance to pipeline maintenance matters):
• Condition 5 – Establishment of a Community Liaison Group (including, among others, the landowners whose land is required to be accessed to inspect and maintain the pipeline)
• Condition 20 – Provide an Annual Monitoring Report for the period 1 July – 30 June each year summarising compliance with the conditions of the permit, including monitoring, compliance, reasons for non-compliance, measures to improve performance (proposed or constructed), and any other issues.
• Condition 21 – All monitoring and reporting undertaken in accordance with consent conditions to be to the satisfaction of the Regional Council.
2.4 Repairs to Date
Condition 23(b) requires reporting on repairs undertaken since the issue of the consent.
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Significant repairs to the pipeline in response to observations from inspections undertaken prior to and following the issue of the existing discharge permit in 2010, are summarised as follows.
• 1993 – numerous pipe blockages, particularly at pipe bridges, were cleared and pipe bridges replaced with 450mm flush jointed stressed pipe bridges; • 2001 – numerous (mainly minor) leaks were repaired; • 2007 - numerous (mainly minor) leaks, undermining encasement defects, pipeline backfall and root intrusion were repaired; • 2013 – repairs undertaken following pipeline failure due to damage from a tree blown over in a storm. Repairs on average are now only required 2-3 times a year and are generally to ensure the integrity of the pipeline is maintained and protected.
2.5 New Consents Required to Undertaken Repairs & Maintenance
Most of the approaches required to achieve pipeline integrity require resource consents under GWRC’s Regional Freshwater Plan to be obtained in advance. This is because they involve a range of works, activities and materials in the bed of the Karori Stream (i.e. clearance of gravels and debris, deposition of gravel, river crossings, construction of access platforms, repair of access fords, disturbance of stream bed material, and deposition of new material on the stream bed and diversions of stream flows).
This MMP covers the necessary works and information required to support resource consent applications for these “in-stream” works.
2.6 Works within Sensitive Catchments
The Karori Stream has been recognised by GWRC and others as having the potential to provide a good quality habitat for indigenous fish species. Planting/stream care programmes supported by GWRC are underway in the upper reaches of the stream, upstream of the WWTP, to help control water temperature and enhance habitat values.
This MMP aims to continue to protect and maintain the assumed potential high quality of the freshwater aquatic habitat as far as is practicable. The approach acknowledges the “values” associated with the stream and seeks to maintain and protect these by good practices to minimise silt release during repair and maintenance works and associated impacts on freshwater aquatic habitat values.
2.7 Limitations to Monitoring covered in this MMP
This MMP is solely focussed on ensuring the ongoing integrity of the MOP for its intended lifetime until replacement. Monitoring referenced in this report therefore only relates to effects of the proposed maintenance works and tests to determine whether maintenance or repair works are required. It does not cover monitoring or quarterly reporting of wastewater flows required by the existing consent conditions 6, 9(a), 9(b) and 25 which relate to effluent quality.
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3. LOCATION & ACCESS INFORMATION
The Main Outfall Pipeline (MOP) runs between Wellington City Council’s Western Wastewater Treatment Plant (WWTP, located near the end of South Karori Road) and the mouth of the Karori Stream on Wellington’s South Coast at the end of South Makara Road. This is shown approximately as a red line in the image below.
Figure 1 Aerial Location Plan – Annotated Extract from Google Earth Online Maps
The MOP largely follows the alignment of the Karori Stream through a varied environment which ranges among steep sided, narrow gorges and open braided gravel channels.
South Makara Road provides access to the pipeline, the public formation terminating approximately four kilometres from the South Coast outfall.
Four-wheel-drive access is available from the end of the road to the outfall. This follows a forestry track constructed over the alignment of the unformed extension of South Makara Road (legal/paper road). The track runs parallel with the Karori Stream and crosses it several times, via fords. Most of the “paper road” access occurs on land owned by CS & PA Griffiths, the NZ Forestry Group or Terawhiti Farming Company. Public access is not available over the track without prior permission of the affected private land owners whose land also has to be accessed.
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The existing track provides easy access to the majority of the pipeline from the bank areas without the need to access the stream bed with machinery when pipeline repairs are required. As summarised on Figure 2 (refer also enlarged copy at Appendix A), farm tracks provide access over private land to those parts of the pipeline or stream not adjacent to the access. The Erin Go Bragh farm track is used to get vehicles from the end of South Makara Road as close as possible to the northern 600 metres of stream (approximately) from where the pipeline can normally only be accessed by walking.
Fig 1.1 etc are references to photographs in the Resource Consent Application. Refer Section 4 of this MMP for more details.
Figure 2 Summary of Access to Pipeline (provided by Wellington Water)
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4. THE MAIN OUTFALL PIPELINE (MOP)
The MOP, constructed in 1934, carried untreated wastewater until 1997 when the WWTP was constructed. It now carries fully treated wastewater from the WWTP to a near shore ocean outfall structure close to the mouth of the Karori Stream on Wellington’s South Coast.
The single 375mm diameter, concrete pipeline has an estimated flow capacity of 190 litres/second. In extreme flows after heavy or prolonged rainfall events, milli-screened wastewater is diverted via a separate approved overflow pipe to the Coastal Outfall structure. In worst case flow events, treated wastewater is also discharged via an approved overflow pipe to the Karori Stream adjacent to the MOP.
The MOP largely follows the alignment of the Karori Stream for a distance of 6.2 kilometres. The pipeline construction features pipe bridges that span parts of the stream, burial in the stream banks, or encasement in concrete (as shown in the following images). The pipeline also passes through tunnels and land that is clear of the stream.
Figure 3 Examples of MOP Construction (Pipe Bridges, Concrete Encasement, Overflow)
The following images illustrate sections of the pipeline and the coastal outfall structure.
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Figure 4 Entrance to Non-Public Section of South Makara Road (Kinnoull Station)
Figure 5 Overflow Location (Storage Tank to Karori Stream)
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Figure 6 Pipe Bridge #1 in Upper Reaches near end of South Makara Road
Figure 7 Coastal Outfall Structure
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Figure 8 Example of a Ford Crossing Karori Stream near the Pipeline
Figure 9 Pipe Bridge following Foundation Stabilisation to Protect from Scouring
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Locations of photographs on previous pages and those referenced on the Summary Access Plan Fig 2 are marked in the table below.
Photograph Location Details Description Reference
Images Referenced on Summary Plan Fig 2
Figure 1-4 2400m upstream of outfall A section of pipeline encased in (UOO) concrete with deep pool below
Figure 1-5 900m-1500m UOO Pipe Bridge No. 2 – before and after scouring repairs Figure 1-6 900m-1500m UOO Pipe Bridge No. 2
Figure 1-7 Upper reaches of pipeline Risk to pipeline presented by slips and trees falling in slip events. Figure 1-8 Lower reaches of pipeline Stream showing braided channel nearer coast. formation (pipeline out of view) – near coast. Figure 1-9 900m-1500m UOO Views of scouring on pipe bridge #2 Figure 1-10 Near Pipe Bridge #2 View of Karori Stream showing diversion works to protect pipeline Figure 1-12 Refer Section 3.5.1. Global Aerial Photo – annotated with RC Application Diversions at areas A and B
Figure 1-13 Refer Section 3.5.1. Global Stream diversion at Area A RC Application Images in this MMP Fig 3 Various Examples of MOP Construction Forms (Pipe Bridges, Concrete Encasement, Overflow to Stream) Fig 4 Entrance to Non-Public Section of South Makara Road Fig 5 Overflow from Storage Tank to Karori Stream
Fig 6 Pipe Bridge in upper reaches of Karori Stream (see Fig 2 reference to Pipe Bridge #1) Fig 7 Refer Fig 2 for location. Coastal Outfall Structure Fig 8 Example of Ford Crossing
Fig 9 Pipe bridge after stabilisation work Fig 16 Refer Fig 2 for location. Solar Powered Flow Meter near Coastal Outfall Structure
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5. INSPECTIONS
5.1 Consent Requirements
Condition 22 of the existing discharge permit for the Main Outfall Pipeline (MOP) WGN060283 [25226] requires inspections of the MOP to be carried out at least every three months with repairs undertaken as soon as practicable depending on what was observed. The condition also requires a full inspection to be undertaken on an annual basis.
The condition also specifies that the MMP should set out the procedures to be used for inspections, including the identification of faults in the pipeline.
5.2 Frequency of Pipeline Inspections
The following procedures for inspections adopt the criteria for quarterly inspections set out in Resource Consent WGN060283 [25226] Condition 22. Undertaking inspections at monthly intervals enables repairs and maintenance to be responded to more promptly following inspections of the condition of the pipeline.
Planned inspections of the MOP need to be sufficiently frequent to ensure its integrity is protected and maintained. The table below sets out the programme for planned and unplanned inspections:
Inspection Frequency Detail
3-Monthly Vehicle based inspection of pipeline from South Makara Road end to Coastal Outfall.
Annual Full inspection of pipeline including walkover on walking only access section in January/February when weather conditions are good.
Events based A full inspection of the pipeline is undertaken following major storm/severe weather events or earthquakes which may have caused slips or damage to the pipeline or increased risk to the pipeline. Inspections are also triggered:
• When telemetry information from the Solar Powered Flow Meter near the Coastal Outfall shows a change in flow rate in the MOP or data from the meter is not received. Inspections need to check for leaks and/or whether the Flow Meter is working correctly.
• In response to notification of events such as tree fall.
Any maintenance or repair works triggered following inspections should be undertaken as soon as practicable.
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5.3 Procedures for Inspections
5.3.1 All Inspections
Before undertaking any pipeline inspections, staff involved must:
1. Hold a current Warrant of Authorisation (WOA, Identification giving approval to enter private property in accordance with Local Government Act (LGA) duties.
Contact the Contracts Officer (refer Section 10) to obtain one if you don’t have a WOA. You may only access private property if you hold a WOA or are accompanied by someone who holds a WOA. Contractors authorised by Wellington Water do not require a WOA.
2. Notify relevant landowners in accordance with procedures set out at Section 9. Contact details are provided at Section 10.
3. Pack necessary equipment into inspection vehicle – refer Checklist at Section 8.2.
During Inspections, the following must be undertaken:
1. Comply with Health & Safety Requirements set out at Section 8.1;
2. Check condition of pipeline – refer Inspection Procedure set out in Section 5.4.
3. Record pipeline condition and any defects observed, undertake sampling and monitoring as required for inspection period, ensure all new hazards are identified and recorded accurately to update hazard register. Separate procedures for recording hazards, defects, sampling and checking the flow monitor are provided in the following sections.
On return from all inspections the Follow Up actions at Section 5.7 must be completed.
5.3.2 Event Based Inspections
The sections of the pipeline visible from the vehicle are to be inspected on each occasion to look for defects and risks to the integrity of the pipeline.
Staff should follow the procedure set out below:
1. Ensure compliance with requirements in Section 5.3.1 above;
2. Complete the Defect Record Form - refer copy of Form at Appendix D and Section 5.4 for how to identify defects. If any defect is observed along the pipeline, also refer to Section 5.7 for follow up procedure;
3. Take a 200mL sample from the stream flow at every suspected leak site to test for faecal coliforms and fluoride, following Sampling & Assessment Procedure set out at Section 5.6.
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5.3.3 Annual Inspections
Inspections carried out on a 12-monthly (Annual) basis shall adopt the criteria set out for 3-monthly and events based inspections in Sections 5.3.1 and 5.3.2, and shall also include a walkover of the entire length of the pipeline including areas not readily accessible by vehicles.
The best time to undertake the annual MOP inspection is during the summer months of January/February.
5.4 Procedures for Identifying & Recording Faults in the Pipeline
The purpose of inspections is to assess the pipeline for defects and report any found so that repairs can be made as soon as practicable.
When undertaking inspections of the pipeline, look for the following indicators of defects which may result in or represent a leak in the pipeline:
Defect Type What to Look For
Leaks Inspect pipe bridge ends, wet areas, and check for evidence of erosion near the pipeline.
Pipe Defects Undermined pipe, backfall/uphill pipe.
Encasement Defects Broken or cracked encasement, missing support nuts/bolts on pipe bridges.
Vegetation Growth
• Access track Vegetation should not prevent sections of the pipeline overgrown/blocked. from being inspected.
• Excessive A leak in the MOP will release nutrients encouraging plant vegetation growth in growth close by. This will be most noticeable in summer vicinity of MOP. months when plant growth is promoted. Samples should be taken if this is observed.
Erosion Check the stream alignment for potential erosion of the pipeline foundations, or damage from slips.
The following photographs show examples of the above-mentioned types of defects.
Where any defects are observed, the Defect Record Form must be completed for every defect observed (refer copy of Form at Appendix D), referencing every defect observed separately. The information recorded on the form must be supplemented as appropriate by attaching photographs and other information considered relevant to the back of the form, with all documents correctly labelled for reporting purposes later
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Figure 10 Four Examples of Pipe Defects (cracks) and Repairs Undertaken
Images clockwise from top left: Broken Joint, Crack repaired on manhole, repair to pipe connection with manhole, repair to encasement.
Figure 11 Two Examples of Pipe Defects (cracks) and Repairs Undertaken
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Figure 12 Examples of Encasement Defect and Repairs Underway
Nutrients in effluent released from cracks in the pipeline encourage plant growth which looks bright green and in contrast to the surrounding vegetation (as shown in the images below).
Figure 13 Examples of Vegetation Overgrowth Growth that indicates a Leak
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Figure 14 Examples of slips which can impact on Pipeline
Figure 15 Example of stream flows undermining rock below pipeline encasement
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5.5 Procedure for Flow Monitor Data Capture
WGN060283 [25226] Condition 6 requires continuous monitoring and recording of the flow rate and volume of treated wastewater entering the outfall pipeline and the flow rate and volume of the wastewater discharged to the South Coast. A summary of records listing the daily discharge volumes and the minimum, average and maximum monthly volumes is required to be forwarded to GWRC at quarterly intervals (as per the Quarterly Reporting specified at Condition 19 of the same consent).
Details of the monitoring and reporting requirements for the flows measured at the outfall are included in this MMP to help identify whether there are leaks in the MOP, so they can be repaired in a timely manner as required in Condition 22 of consent [25226].
A solar powered flow monitor (shown in image below) is located at Manhole MAK 175 near the Coastal Outfall Structure (refer location on Fig 2).
Figure 16 Solar Powered Flow Meter located near Coastal Outfall
The Flow Monitor (meter) sends flow monitoring data back to the office by telemetry. If this data stream ceases or trends in data indicate a change in flow rates, the meter needs to be inspected and the pipeline may need to be inspected for leaks.
The meter should also be checked on every inspection of the pipeline to ensure it is working correctly. If the data has not been sent to the office automatically, it can be manually downloaded from the meter when undertaking inspections.
5.5.1 In the Office
Checks of the flow monitoring data need to be made periodically to ensure it is being sent and observe any trends in flow rates and compare these trends with WWTP flows. Where trends indicate a change in flow rate and/or the data is not being received, refer Follow Up procedures at section 5.7.
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5.6 Sampling & Assessment Procedure
5.6.1 Testing for Suspected Pipeline Leaks
WGN060283 [25226] Consent Condition 22(b) requires the MMP to include, among other things, details of any indicators that the pipeline or part of the pipeline may require repair or replacement
Wherever a defect is observed along the pipeline, in addition to the reporting procedures to arrange repair work, it is necessary to take a sample of water from the stream flow nearby. The water is then required to be tested for faecal coliforms and fluoride and the results compared with known indicators of wastewater contamination (hence determine if there is a leak).
The procedure below provides the information required to ensure viable samples are taken and protected in transit to the laboratory. A table sets out the comparison indicators for assessment and reporting procedures.
5.6.2 Sampling Technique
Preparation for inspections should include packing appropriate equipment for sampling into vehicle (set out at Section 8.2) and checking that the staff member responsible is trained in correctly taking and protecting samples.
When taking sample:
1. Only use sterile sample bottles (sourced from Eurofins Laboratory-refer Section 10 for contact details). Complete any labelling requirements (it is easier to write on a dry label).
2. After removing the bottle lid, take a 200mL sample from the stream flow at every suspected leak site. The water is then collected by dipping the bottle directly into the flows.
3. Replace the bottle lid and ensure it is tightly closed to avoid leaks. Place the bottle in the chilly bin.
5.6.3 Sample Storage & Transfer to Laboratory
1. Keep the bottle in the chilly bin and protect the container from sunlight until it can be taken for testing at the laboratory.
2. Take the samples to Eurofins Laboratory Services – For address and contact details refer to Section 10.
3. There is a standing arrangement at Eurofins whereby the order for testing samples is entered “on-line’ by Contracts Officer and confirmed at the time of delivery to the laboratory at the reception desk. The receptionist at Eurofins will be able to provide assistance when you arrive at the laboratory with the sample.
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5.6.4 Sample Assessment
1. When the results are received from the laboratory, check these against the guidelines provided in the table below to determine whether or not a sample contains leaked wastewater from the MOP. Note it is often difficult to determine this.
Comparison Indicator Faecal Coliforms (cfu) Fluoride (Mg/L)
Rain water 0 0
Karori Stream water 200 – 1,000 0
Groundwater 1 – 200 0 – 0.4
Farm Runoff 0 – 10,000 0
Outfall Pipeline Effluent 50 – 1,000 0.8
2. Relevant Follow Up actions at Section 5.7 must be completed.
5.7 Follow-Up
The following table sets out the follow up procedures for inspections and maintenance:
Task Follow-Up Procedure
Observed Defects on Where any defects are observed along the pipeline, Pipeline the Defect Record Form must be completed, with a separate entry and photograph provided for every defect observed (refer copy of Form at Appendix D). The completed Defect Record Form(s) must be submitted to Contracts Officer on completion of the inspection, including any photographs or other information to assist in determining what maintenance and repairs will be required. The Contracts Officer to visit defect sites and determine and programme maintenance and repair works required and engage contractors. Completed works to be reported by the Contracts Officer to the Consent Manager for quarterly and annual reporting.
Observed Faults with Flow As above Meter
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Task Follow-Up Procedure
Flow Meter Data Recording Flow meter data is received automatically (refer section 5.5). If this does not occur a manual download can be undertaken at the meter. Data must be provided by the Contracts Officer to the Consent Manager for quarterly and annual reporting.
Identification of Hazards Where any hazards are identified during pipeline inspections and maintenance events, each of these must be recorded on the Hazard Identification Sheet (refer copy of sheet at Appendix C). However, make sure you have the latest version of the Hazard Sheet before undertaking any site inspection so you are aware of all the most recently observed hazards. Where hazards referenced on the Hazard Sheet no longer exist, this should be recorded. The information on the completed, updated form is to be provided to the Consent Manager on return to the office and the Hazard Register updated.
Identification of Leaks Where a leak in the pipeline is detected through analysis of the grab sample taken from the stream near an observed defect, the information is to be provided to the Consent Manager for quarterly and annual reporting. Details of any subsequent repairs (or planned repairs) and the outcome of these is also required to be referenced in reporting processes.
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6. MAINTENANCE AND REPAIRS
6.1 Consent Requirements
The existing suite of consents held for the WWTP discharges require ongoing maintenance and repairs of the MOP until it is replaced. This necessitates access and maintenance activities at regular intervals and following storm events or other natural hazard events to repair or protect the MOP. However, while ongoing repairs and maintenance are specified by existing consents, some of the necessary activities require new consents under the Regional Freshwater Plan, as they are not authorised by the existing consents.
Condition 22(g) of existing discharge permit WGN060283 [25226] requires that any leaks detected during pipeline inspections are to be repaired as soon as practicable.
The condition also specifies that the MMP should set out the procedures to be followed before, during and after repairs to the pipeline.
6.2 Responsibilities of Contracts Officer
The Contracts Officer is responsible for supervising all repairs and maintenance of the MOP covered by this MMP.
In addition to the procedures and responsibilities set out at Section 4.2.1 earlier, the following must be complied with.
1. Visit the site(s) referred to in the Defect Record Form as soon as practicable to determine:
(a) What works are required (e.g. repair work or replacement of pipeline structure or less urgent works such as vegetation clearance);
(b) The urgency for the work to be completed (e.g. as soon as practicable or less urgent); and
(c) Who should carry out the works.
2. Engage a contractor to carry out the necessary works;
3. Set up a timetable for the repair work;
4. Keep other relevant staff informed on progress at regular intervals;
5. Supervise the repair work through to completion, ensuring that the repair procedures, methodologies and mitigation methods set out in this MMP are followed by all staff and contractors involved.
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6.3 Responsibilities for All Maintenance & Repair Work
Before undertaking any pipeline maintenance and repair work (including site visit to follow up on defect reports to determine work requirements), all staff/contractors involved must:
1. Notify relevant landowners in accordance with procedures set out at Section 9. Contact details are provided at Section 10.
2. Pack necessary equipment into inspection vehicle – refer Checklist at Section 8.2.
During Site Visits and Maintenance and Repair Works, the following must be undertaken:
1. Comply with Health & Safety Requirements set out at Section 8.1.
On return from all site visits and when works are completed the relevant Follow Up actions at Section 5.7 must be completed.
6.4 Overview of Typical In-Stream Maintenance & Repair Works
This MMP sets out details of all in-stream activities and structures required to gain access to all parts of the pipeline and undertake planned and unplanned repairs and maintenance. The range of maintenance and repair works that may need to be undertaken along the MOP includes:
• Clearance of slip or flood debris (including fallen trees that have come down with slips);
• Repairing scoured sections of stream bed affecting the pipeline stability;
• Repairs to fords/river crossings (re-grading);
• Construction of access ramps/platforms for machinery to safely access the pipeline;
• Disturbance and redistribution of bed material (including deposition of redistributed material) on the bed of the stream to create stable access and works areas or divert scouring flows away from the pipeline; and
• Temporary and permanent diversions to facilitate works.
The potential adverse effects of the maintenance and repair works set out in this MMP are limited to disturbance of the bed and banks of the stream and potential release of sediment and effects on freshwater aquatic habitat. The MMP includes methodologies and mitigation measures to address the relevant effects on the environment and ensure that they are managed to an acceptable level so as to be not more than minor.
The following sections set out the types of repairs likely to be required for the pipeline and the methods of work in the Karori Stream to perform those repairs, to ensure the quality of the stream and freshwater habitat are protected.
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6.5 Vegetation Clearance
Where vegetation growth is preventing accurate and efficient inspection of the pipeline or access along inspection track, this needs to be removed, subject to the following procedures being complied with:
1. Notify relevant landowners in accordance with procedures set out at Section 9. Contact details are provided at Section 10.
2. Comply with Health & Safety Requirements set out at Section 8.1, and in addition to this, ensure:
(a) A minimum of 2 staff are on-site with scrub cutting equipment to clear access track;
(b) Spray work is undertaken by hand where vehicle access is not possible or safe. A vehicle mounted spray unit may be used where safe access is available.
3. All vegetation cleared shall be removed from the site, unless otherwise agreed with the landowner, and disposed of at the Southern Landfill or other approved disposal site.
4. Notify affected landowners when work has been completed (as per item 1 above).
6.6 Acceptable Methods of Repair for Pipeline Leaks
Once a leak has been detected and confirmed, the following procedures shall be followed:
1. Notify the affected landowners about:
(a) The timing of the repair works (once confirmed with the contractors); and
(b) When works have been completed,
Notification shall occur in accordance with procedures set out at Section 9. Contact details are provided at Section 10.
2. The Contracts Officer shall determine with the contractors the best way to repair the leak and the timing of the work.
3. Depending on the location and nature of the leak, one of the following repair methods will be used (all of which must be kept clear of stream flows):
• E-par (epoxy concrete repair compound); • Reinforced concrete bandage and cement encasement; • Install rubber seal on a section of pipe; • Flexible joint - where expansion or movement is expected (e.g. on a pipe bridge).
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Figure 17 Example of Reinforced Concrete Bandage & Cement Encasement
Notes:
• If required, the flows in the pipeline can be stored at the Wastewater Treatment Facility for short periods of time to enable repairs to be completed. Refer WWTP contact details at Section 9 to make arrangements if necessary.
• When the works are to be undertaken, additional “in-stream” activities may be required to gain access to the pipeline or protect its integrity. The following sections set out details of these activities and methodologies to avoid adverse effects of works on the Karori Stream environment.
6.7 Types of In-Stream Works Anticipated for Repairs and Maintenance
This section of the MMP describes the situations when certain types of works will be required to be undertaken in and around the stream bed and banks, and explains the issues that need to be addressed followed by the methodologies to avoid or mitigate any adverse effects of those works on the stream environment.
6.7.1 Clearance of Flood or Slip Debris
Flood debris, slip debris or fallen trees will be removed, whenever required, from the channel of the Karori Stream to ensure there is no risk of damage to the MOP.
Areas where clearance may be required include, but are not limited to:
• Sections of the channel which have become blocked (e.g. in narrow, incised areas of watercourse);
• Areas where debris has built up against the pipeline structure (e.g. pipe bridge supports) and presents a risk to the integrity of the pipeline; and
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• Where flood waters diverted by debris present a risk to the pipeline structure and its integrity.
Removed material will be disposed of at an appropriate land based disposal area.
For areas where the debris is accessible from the stream banks (and subject to suitable access to the bank from roads) a hydraulic excavator will be used and (if material is not redistributed in the stream bed) the cleared material may be loaded on to a truck (suitably sized for the volume involved), which will be parked on the side of the watercourse.
Where the vehicle access is not suitable for the excavator, or the reach of the excavator is not sufficient to remove material from the bank, it will be necessary to use a tracked vehicle. The vehicle will access the stream bed from the closest safe position on the stream bank and travel up the stream bed to the works area.
6.7.2 Deposition of Gravel
The physical characteristics of the stream environment (flow, velocity, channel geometry) and the design of existing pipeline support structures in the stream bed have the potential to create scour holes in the stream bed. Gravel will be deposited where scour holes arise in locations that can threaten the integrity of the MOP structure.
When scour holes are identified during inspections and follow up by the Contracts Officer (CO), a visual assessment will be made of the:
• Severity and extent of the undercutting,
• Likely risk of exposing the support foundation of the pipeline, and
• Availability of riverbed material in the immediate vicinity of the scour hole.
The results of the visual assessment by the CO will determine the course of action to address the scour hole. For example, deciding whether infilling or replacement of scoured gravel material is necessary, and when the work would need to be undertaken. A pragmatic approach is necessary for dealing with the dynamic nature of the stream bed.
The following image shows an example of gravel re-contouring works which enabled the Karori Stream to be diverted to an alignment with less risk to the pipeline.
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Figure 18 Example of Gravel Re-contouring to Divert Flows
6.7.3 Construction of Temporary Access Platforms
Temporary access platforms may need to be formed in the bed of the stream where it is not possible to work from the bank of the stream. Working from the bank is not possible, for example, where:
• The distance between the bank and the watercourse is too great to use machinery based on the bank (difficulties with reach of excavator);
• The watercourse bank is too steep or does not offer sufficient width from which to safely or practically base the machinery; or
• Access is only available via the bed of the stream and machinery has to be driven up to the works area.
The extent of the platform formation will depend on the pipeline maintenance/repair requirements (and hence the type and size of machinery involved) and the nature of the stream bed where the works are required or where access via the stream bed is required.
Typically, a platform needs to be created when there is often a deep pool on one side of the stream bed which does not allow machinery to operate safely on a level area of stream bed. The area needs to be filled with sufficient material to create a level work area for machinery which cannot safely work from the bank clear of flows. The size of the platform would be kept to the minimum necessary for safe working of the machinery.
A temporary access platform should be created from suitable, locally sourced gravel material (estimated particle size 2mm-200mm) and may potentially be constructed with
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a boulder base using larger material sourced locally (particle size >200mm). This is usually undertaken by moving the material from nearby areas into the deeper sections.
There will be no ability to screen the gravel in situ so sizes of particles are provided as an estimate only.
To avoid the effects of further disturbance on downstream waters, the re-contoured streambed is left to be reshaped naturally by stream flows over time. The dynamic nature of the stream flows means that the stream bed will reinstate itself relatively quickly.
6.7.4 Re-Grading of Existing Fords
There are several fords that cross the stream on the paper road alignment used to access the pipeline. From time to time these are damaged by storm flows and need to be regraded. Similar methods used for Temporary Access Platforms will be employed in these situations.
In these cases the areas will rely on remaining compacted/stable for future use.
6.8 Works Methodologies & Mitigation Measures
Unless already detailed in the previous sections, the types of works described in the previous section will be undertaken in accordance with the relevant methodologies and mitigation measures set out below (to minimise any adverse effects that the activities could have on the Karori Stream environment). For example in order to protect or repair the pipeline it may be necessary to divert flows away from the structure. The diversion activity will be undertaken following a specific methodology and including suitable erosion and sediment controls to protect downstream waters and fish habitat.
Refer Appendix E for Fish Rescue Methodology. This may be required to be employed when works affect a stream length exceeding 50 metres.
6.8.1 Diversions (Temporary and Permanent) & Works in Active Flowing Sections of Stream
Diversions are required to separate works areas from the flowing channel. These will typically take the form of a stabilised system (e.g. a gravel bund or an excavated channel or a combination of both) in the dry stream bed. The diverted flows will then be discharged back into the stream channel below the works using gravel bunding or contouring to avoid scour.
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Figure 19 Example of Diversion Works to Protect Pipeline
The image above shows the stream after permanent diversions were undertaken.
To achieve this, a channel was formed in new location away from the pipeline (in the dry). The stream was then diverted into the new channel and additional gravel bunding positioned to divert future flows away from the MOP and protect its integrity.
Where possible, a temporary diversion methodology involving opening a channel in the dry bed without breaking into the stream flow will be employed as a preventative measure.
This approach means the stream is left to break through naturally at the upstream end of the channel during natural high flow events (i.e. reliance on the natural changes in the stream channel during and after flood flows as a means to try to manage the outcome and move the flows away from the vulnerable MOP structure). It is considered preferable to allow the stream to find its own path rather than diverting the stream back on completion of the works (which would create more disturbance).
However, there may be some instances where it is not feasible to divert the stream away from works areas due to physical characteristics which could constrain options – and works in the active flowing sections of the stream will be necessary. If a diversion is not feasible, every effort should be made to minimise adverse effects on the downstream environment by working quickly to minimise the time of disturbance.
In some cases a permanent diversion will be necessary to move flows away from the MOP and prevent destabilisation of support structures.
Any future temporary or permanent diversions that may be considered necessary to protect the MOP, shall be undertaken generally in accordance with the “general procedures for temporary diversions” in Section 6.1 (pages 87-88) of the GWRC Sediment and Erosion Control Guidelines (September 2002). The Guidelines refer to
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use of a range of materials (i.e. geotextile cloth or concrete) as well as gravels that can be used. However, no materials other than the in situ gravels and/or rock should be used in diversions undertaken to protect the MOP.
The steps suggested in the Guidelines which cover minimising sediment generation and discharge from diversion works within a water body will also be followed. Refer additional details below.
6.8.2 Erosion and Sediment Controls
Works to create temporary diversions, construction platforms and fords, and vehicle access in the stream bed all have the potential to cause sediment to be released into the watercourse or alter the stability of the stream bed or banks. Other aspects of maintenance works, such as gravel re-contouring or stockpiling of debris and aggraded gravels, can also have similar effects.
The degree of sediment release depends on the extent and duration of works and whether or not they occur in flowing sections of the watercourse.
Erosion and sediment shall be managed on a case by case basis as and when works are required to be undertaken in and around the pipeline with a view to minimising sediment generation. The nature of the measures implemented will depend on the specific watercourse setting, the type of works being undertaken in each instance, and the extent to which access or disturbance of the bed and/or banks of the stream is required.
Typical sediment controls will include, as far as practicable:
• Limiting planned maintenance works to times of low flows, enabling disturbance to occur in the dry and/or separate from the flowing channel; and
• Ensuring planned works that must occur in flowing sections of the stream avoid peak fish spawning/migration period (1 August to 31 December) if required – noting the stream is not managed by GWRC for aquatic habitat and is not listed in the Regional Freshwater Plan for any other reason (these documents set specified periods to be avoided based on values to be protected).
It is not practicable to install silt fencing during temporary in-stream works, so it is not proposed as a mitigation measure. The potential effects are already minimised due to the duration of the works usually being quite short (2-3 days at most) and most of the time work is able to be undertaken in the dry, with the remainder only affecting a small area of stream bed. Events requiring maintenance (planned or unplanned) are very infrequent, being 2-3 times a year on average.
The stream bank will be repaired if remedial works cause scour or erosion.
6.8.3 Other Contaminant Controls
Repairs to the pipeline can, in some cases, involve repair of concrete support structures or casings that protect the pipe. Wet concrete or dry mix must never be permitted to enter the stream flows and all works involving concrete repairs must be
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undertaken as “planned” works “in the dry”. Any risk of spillage of oil or diesel from machinery to stream flows shall be avoided. This approach protects the freshwater aquatic life-forms from contamination risks.
6.8.4 Fish Passage
Fish passage shall be maintained at all times.
The methods of setting up stable access platforms and fords described earlier will alter the surface of the stream bed and include compaction of material. However, this is temporary and short term work which will only affects small sections of stream bed at any one time (with an estimated frequency of not more than 2-3 times a year on average).
The surface of the stream bed will be compacted to achieve a stable platform or access but natural stream flows will over time reinstate the interstitial spaces relied on as refuge by native fish. The small areas affected are not expected to adversely impact on eel habitat or migration over these areas. Where possible, most of the works will be carried out “in the dry”, further minimising potential impacts.
Figure 20 Examples of Vegetation Removal from Pipeline to enable inspections and types of Debris which needs to be removed to protect Pipeline
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7. MONITORING & REPORTING
7.1 Consent Requirements
Condition 21 requires all monitoring and reporting undertaken in accordance with consent conditions to be to the satisfaction of the Regional Council.
Condition 22 of existing discharge permit WGN060283 [25226] requires monitoring of the condition of the pipeline and repairs to be made as soon as practicable (covered in previous sections on Inspection and Repairs).
Condition 23 requires an Annual Report for the MOP to be provided by 31 July each year to GWRC and members of the Community Liaison Group (CLG) addressing activities undertaken the previous year (1 July – 30 June). The report needs to include details of: location, extent and duration of any leakage of faults, and the timing, nature and success or remedied action taken to remedy leaks or faults; any other works undertaken (including any repairs and replacements), and any work planned within the next 12 months to repair or replace the pipeline.
7.2 Annual Reporting
An annual report for the past 12 months shall be prepared by the Consent Manager and submitted to GWRC by 31 July each year covering the following:
(a) The number of, and details of, overflows that have occurred;
(b) Details of all leak repair work undertaken;
(c) Inflow and infiltration (I/I) work undertaken within the catchment.
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8. GENERAL MANAGEMENT
8.1 Health and Safety Provisions
8.1.1 General
All contractors shall have an approved Health and Safety Plan in accordance with the Health and Safety Act 1992.
The contractor shall comply with all relevant health and safety regulations and adopt best practice guidelines for activities occurring on and off site which are directly related to the nature of works required.
8.1.2 Inspections
For all inspections: staff must comply with the following:
(a) A minimum of two (2) people is required for all inspections;
(b) Try to set the inspection to follow a period of dry weather, and check the weather forecast to ensure fine weather on the inspection day;
(c) Review and be familiar with all identified hazards listed on the latest Hazard Register (refer to Hazard Identification Sheet at Appendix C and check with the Contracts Officer for latest version of this).
(d) Take a copy of the latest Hazard Identification Sheet and
(i) record whether hazards listed on the Sheet are still present or not, and
(ii) add details any new hazard observed;
(iii) attach photographs and other information to help explain where the hazard is and the nature of the hazard;
(iv) Take day trip gear (Refer table in Section 8.2);
(v) Wear PPE (Refer table in Section 8.2).
8.1.3 Maintenance & Repair Work
For all maintenance and repair works: staff and contractors must comply with the following:
As above for Inspections.
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8.2 Equipment Requirements
Take the items listed below for monitoring, inspections or repairs and maintenance activities and any other necessary equipment, monitoring forms or resources required to meet tasks referenced in other parts of this section of the MMP:
Equipment Monitoring Inspections Repairs Comment Maintenance
Camera √ √ √ Record observations for later reporting
Sampling √ √ Routine Monitoring Bottles & Chilly and for Checks of Bin suspected leaks. Take suitable bottle for specified sampling – refer Section 5.6.
Manhole Key √ √ √ A manhole key should be kept in all maintenance vehicles. It is used to lift manhole covers for inspections inside manhole structures on the MOP, looking for cracks or defects.
Writing Material √ √ √ To record any observations
Day Trip Gear √ √ √ Health & Safety (water, lunch, Requirement hat, sunscreen, and first aid kit rain jacket/ warm jacket)
Personal √ √ √ Health & Safety Protection Requirement Equipment (PPE, hi-viz clothing, safety boots), hand sanitiser.
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Equipment Monitoring Inspections Repairs Comment Maintenance
Copies of all √ √ √ Refer Appendices C forms for and D. recording Defects, Hazards, and completing monitoring requirements
8.3 Discovery of Artefacts
If koiwi, taonga or other archaeological material is discovered in any area during the works, work shall immediately cease and the consent holder shall contact Ngati Toa Rangatira, Heritage New Zealand and Wellington Regional Council within twenty four hours.
If human remains are found, the New Zealand Police shall also be contacted. The consent holder shall allow the above parties to inspect the site and in consultation with them, identify what needs to occur before work can resume.
Note: Evidence of archaeological material may include burnt stones, charcoal, rubbish heaps, shell, bone, old building foundations, artefacts and human burials.
8.4 Cartage of Materials and Machinery
Vehicles shall be loaded and unloaded in such a manner that there is no spillage in any public place during conveyance off the site, and private land areas used for access to the pipeline shall be left in a state acceptable to the affected land owner.
In the event contaminants are deposited on the roadway, the contractor shall ensure the area is promptly cleaned to the satisfaction of the Wellington City Council.
8.5 Vegetation Removal, Storage & Disposal
The contractor shall ensure that the process of vegetation removal, storage and disposal is undertaken in such a manner that minimises potential adverse effects associated with this process.
This shall involve ensuring that vegetation is disposed of in such a manner that it will not enter a water body or cause diversion, damming or erosion of any waterway.
If required, areas of vegetation to be protected shall be clearly marked to avoid undue disturbance of these areas.
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8.6 Weather Forecasts
The staff member or contractor involved with inspections or repair work shall monitor weather forecasts daily by checking the Meteorological Service of New Zealand webpage (http://www.metservice.com/towns-cities/wellington/wellington-city), and work shall be planned accordingly, giving particular attention to the potential for sediment becoming a noticeable nuisance during the works process, and to avoid any hazards associated with extreme weather events.
8.7 Monitoring, Plan Review and Amendments
The Contract Officer and the Contractor shall meet as required to discuss works on site and environmental management issues.
The Consent Holder (via their representatives) shall work with Greater Wellington Regional Council (GWRC) officers to monitor the impacts of maintenance works and adjust the erosion and sediment controls set out in this plan to ensure that adverse environmental effects are minimised.
In the event that there is a conflict between works requirements on site and this MMP, a review of the MMP shall be undertaken accordingly. This shall occur in consultation with all relevant responsible persons listed at Section 10.
As required by existing consents, the MMP is to be reviewed every five years once it has been approved.
Where changes are required to be made to this document as a result of any review processes, they shall be approved in writing by GWRC in advance of implementation, and attached as a formal record at Appendix F.
8.8 Register of Public Complaints/Incidents and Reporting Procedures
The contractor shall maintain a register of complaints received alleging adverse effects from or related to the site works. This record, which shall be made available on request and shall include (but not be limited to):
• The name and address of the complainant; • The date and time that the complaint was received; • Details of the alleged event; • Weather conditions at the time of the complaint (as far as practicable); and • Any measures taken to remedy the effects of the incident/complaint; and • Measures put in place to prevent occurrence of a similar incident.
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9. CONSULTATION / NOTIFICATIONS
9.1 Consent Requirements
Condition 5 of WGN060283 [25226] requires the establishment of a Community Liaison Group (CLG) and assigns functions to the group to share information about the WWTP and discharges. Membership of the group (now established) includes neighbouring and downstream landowners.
Condition 22 of the consent requires the MMP to include procedures for notifying landowners and GWRC and others about leaks and the nature and timing of repair works.
9.2 Procedures for Notifying Landowners and GWRC and Others
The process for notification was established when the CLG was set up and has been ongoing since that time. The information in this MMP adopts the current process.
9.2.1 Landowners
All notification of relevant landowners must be in writing (by email is an acceptable method) at least 24 hours prior to inspections or works programmes commencing, and on completion of works, subject to the additional comments below:
• The Warrens (Registered Owners: Erin Go Bragh Limited) prefer at least 48 hours email notification and phone notification for all inspections.
• Forestry Group and Terawhiti Station have acknowledged that monthly trips to the Coastal Outfall Structure are routinely carried out.
When maintenance or repair works are proposed, notifications must include details of:
(a) The nature of the leak;
(b) The timing of the repair works (once confirmed with the contractors); and
(c) When works have been completed.
A list of landowners and contact details is provided at Section 10.
9.2.2 GWRC
Annual Reporting to GWRC (outlined at Section 7 earlier) is required to be provided in electronic format (to [email protected]) and as hard copies submitted to the Consents Officer.
GWRC’s Consents Officer must also be contacted when there are leaks detected or any other issues associated with the pipeline discharges.
Contact details for GWRC are provided at Section 10.
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9.2.3 Others
Other parties who may need to be contacted are set out in the following table with reasons for contacting them:
Interested Party Reasons for Notification
Hutt Valley District Health Board Contact in the event of a leak or discharge.
Contracts Officer In the event of repairs being required/hazards observed. Other, e.g. telemetry data capture issues or need for Warrants to allow access.
Contact details for these parties are provided at Section 10.
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10. CONTACT PERSONNEL AND RESPONSIBILITIES
Organisation Responsibility Key Contact Department Role Telephone Email Address
Wellington Wastewater Anna Hector Operations Treatment 910 3872 [email protected] 85 The Esplanade
Water Limited Infrastructure Plant o.nz Petone, Lower Hutt 027 285 6040 Asset Manager Engineer/ on behalf of 910 3801 (fax) Consent Wellington City Manager Council (WCC)
Managing Sam Lister Operations 910 3804 sam.lister@wellingtonwater. contractors, Engineer 021 998 553 co.nz inspections, monitoring and 910 3801 (fax) reporting to ensure consent Malcolm Giles Contracts 910 3834 malcolm.giles@wellingtonwater
Officer .co.nz compliance. 027 249 957
910 3801 (fax)
Adrian Smart Technician 910 3824 adrian.smart@wellingtonwater.
co.nz 027 220 2528
910 3801 (fax)
Wellington Wastewater N/A Call Centre 499 4444 [email protected] 101 Wakefield St City Council Infrastructure PO Box 2199 801 3138 (fax) Asset Owner Wellington
Greater Consent Louise Consents Resource 830 4313 [email protected] 142 Wakefield St Wellington Authority, McKenzie Management Advisor PO Box 11646 Regional Administration of Consent Wellington Council Regional Plans Officer
October 2015 44 Karori Main Outfall Pipeline Management & Monitoring Plan
Organisation Responsibility Key Contact Department Role Telephone Email Address
To be contacted GWRC contd. Pollution Notifications 0800 496 734 [email protected] As above … in the event of a Response .leak/discharge
Hutt Valley Public Health (to Regional Health 570-9002 [email protected] Private Bag 31-907 District Health be contacted in Public Health Protection Lower Hutt 570-9211 (fax) Board the event of a Officer leak/discharge) Call Centre 570 9007 (after hours 570 9211 (fax) ask for on call Health Protection Officer)
Veolia Water Operates Stuart Pearce Operations 388 0065 [email protected] 320 South Karori Rd International Wellington’s Coordinator PO Box 3523 127 466 0563 Western WWTP Wellington
Reception 380 6144 0800 928 371 (24 hours)
388 9760 (fax)
Cardno Global Consent Jenny Grimmett Resource Consultant [email protected] Down to Earth Application & Management Planner 029-200-3057 Planning Limited,
MMP PO Box 36029,
preparation Lower Hutt 5045
Engineering Peer David Beachen / Engineering / Engineering. DDI: 896 9125 [email protected] Manager / Cardno, Level 5, IBM Review Nigel Hillier Contract [email protected] Contract DDI: 896 9131 Building 25 Victoria Supervision Supervisor Main: 478 0342 [email protected] Street, Petone 5012
October 2015 45 Karori Main Outfall Pipeline Management & Monitoring Plan
Organisation Responsibility Key Contact Department Role Telephone Email Address
Eurofins Testing of Jacinta Hira General 568-1209 0800-576-5016 [email protected] 85 Port Road, Wellington monitoring Chemistry Seaview, Lower Hutt 576-5014 (fax) www.eurofins.co.nz samples Sunita Raju Microbiology 568-1206
October 2015 46 Karori Main Outfall Pipeline Management & Monitoring Plan
Landowner Contact Name Company Special Instructions Telephone Email Address Name
Dr Janet and Mr Michael Warren Erin Go Bragh 476 6316 509 South Makara Limited Road, Makara, Wgtn
Mr Philip Uren 476 6316 330 South Karori Road, Karori, Wgtn
Mr Peter Lissington NZ Pine 06 347 9365 [email protected] Management Ltd
Mr Guy Parkinson Terawhiti 476 4804 [email protected] Terawhiti Station Station
Mr Bill Grace Terawhiti [email protected] Terawhiti Farming Farming Co Co Ltd, Terawhiti Farming Director Ltd PO Box 105479 Auckland 1030
Mr Wesley Garratt New Zealand 09 624 2780 New Zealand Forestry Forestry Group, Group PO Box 24 475 Auckland
Mr Clem Griffins Kinnoull 021 644 007 Lot 2 Kinnoull Station Station
October 2015 47 Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX A
Plans of Pipeline
Plan Number Plan Name / Description
Figure 2 Access Summary Plan (original of plan provided by Wellington Water)
700011 Sheet S1 of 3 Plan by Duffill Watts & Tse Ltd – South Karori Sewer CCTV/Sample Locations
(Lower section of stream including coastal outfall)
700011 Sheet S2 of 3 As above (middle section of stream)
700011 Sheet S3 of 3 As above (upper section of stream including Treatment Plant)
Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX B
Resource Consent WGN060283 [25226] & Global Consent WGN***** [**this would be added once application has been approved***]
Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX C
Hazard Identification Form
Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX D
Defect Reporting Sheet (to be updated on each inspection)
Karori Main Outfall Pipeline Management & Monitoring Plan
Defect Record Form – Pipeline Faults & Sampling
Metreage Reference Description Sample No. Photo Ref
Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX E
Fish Rescue Methodology
APPENDIX E – FISH RESCUE METHODOLOGY Karori Stream Main Outfall Pipeline Maintenance – Global Consent – August 2015
Fish Rescue Methodology & Related Mitigation
1.1 Ecological Considerations The construction of stable access platforms and fords will alter the surface of the streambed and may include compaction of bed material to achieve a stable platform or access. However, this temporary and short-term work will only affect small sections of streambed at any one time (with an estimated frequency of not more than 2-3 times a year on average). Natural stream flows will reinstate the interstitial spaces in the compacted areas over time and, given that only small sections of streambed are involved, the works are not expected to adversely impact on eel habitat or migration over these areas. Where possible, most of the other remedial or maintenance works (such as diversions) will be carried out “in the dry”, further minimising potential impacts from sediment release or habitat disturbance. However, additional measures are proposed to ensure fish passage is maintained at all times and to recover (where practicable) any stranded fish during diversion activities.
1.1.1 Timing of Works to Avoid Spawning & Migration The applicant will ensure that planned works that must occur in flowing sections of the stream will avoid the typical indigenous fish upstream migration period (1 August to 31 December inclusive) if required. These dates are preferred as they may assist in minimising any adverse effects of potential in- stream disturbance (sediment etc.) when building platforms are used for maintenance works.
1.1.2 Fish Passage / Fish Relocation Methodology Fish passage will be maintained at all times. Overview To ensure protection of aquatic fauna in the Karori Stream during MOP repairs and maintenance works, a fish rescue methodology is proposed. Two types of piping and diversion are likely to be required to facilitate repairs and maintenance on the MOP. These include:
• Temporary diversion of the stream flow through a flexible pipe which is placed clear of vehicle manoeuvring and works areas, taking flows from upstream of the works area to a safe and convenient location downstream of the works area. Fish passage would be available through the pipe at all times;
• Temporary piping required to facilitate diversion of flows to a new channel and re-connecting stream flows via the new channel to the existing bed downstream. The temporary piping will help to ensure that MOP repairs can occur more efficiently and with minimal risk of contaminating Karori Stream downstream of the work area (due to disturbance of the stream bed or banks during the works), while maintaining fish passage at all times. On completion of the new diversion channel (and stabilisation of the area, if necessary), the flows in the Karori Stream can be introduced into the new channel. For sections of stream (individual or combined) involving more than 50 metres of piping/diversion to a new channel an ecologist will need to be involved. This is because, in these instances, it is important to remove any fish and freshwater crayfish from the affected section of the Karori Stream to be temporarily piped/diverted before any works commence. There needs to be a minimum of 5 days’ notice to the Project Ecologist for this work.
APPENDIX E – PAGE 1 APPENDIX E – FISH RESCUE METHODOLOGY Karori Stream Main Outfall Pipeline Maintenance – Global Consent – August 2015
Methodology Where the diversion or temporary piping involves more than 50 metres (total or combined sections of stream) this requires the involvement of an ecologist, and the methodology in the table below shall be employed. Note: Active transfer of fish and freshwater crayfish into the new channel is not recommended. This is because immediately following the reintroduction of flow there will be little cover and food for the fish and freshwater crayfish. The new channel will in time become naturally colonised.
FISH RESCUE METHODOLOGY FOR TEMPORARY PIPING OR DIVERSION TO NEW CHANNEL Description Responsibility
1.0 Biota Transfer Before Temporary Piping/Diversion
1.1 Alert the necessary authorities and (if needed) obtain permits to allow Ecologist for the transfer of fish and freshwater crayfish.
1.2 Install an in-channel sediment control structure above and below the Contractor proposed temporary pipe section (or length of stream bed affected by diversion to constructed channel). This will act to filter particles from the water and help to prevent upstream passage of fish and re-colonisation during the fish rescue.
1.4 Commence fish and freshwater crayfish removal strategy. Ecologist Depending on the location of the works, and hence the size and nature of the stream in these locations, a number of fishing techniques (electrofishing, spotlighting, hand netting, Gee-minnow trapping) may be required to ensure success, and may need to be carried out over two days. Creation of some deeper pool areas within the channel may also be necessary to encourage fish to congregate and in which Gee- minnow traps can be set.
1.5 Identify and record all captured fish and crayfish before their release to Ecologist provide population size-class data for comparison with any subsequent studies made of the stream and its tributaries. Release all captured fish and freshwater crayfish into suitable habitat areas along the length of the Karori Stream at least 250m upstream of the works area and within the same catchment. If possible select sections of watercourse that are shaded by vegetation for fish release.
• As both banded kokopu and freshwater crayfish are territorial, releasing the fish along the length of vegetated stream will reduce the chance of inducing intraspecific competition.
• Releasing them at least 250 m upstream of the works areas will reduce stress on the fish once the sediment traps etc. are removed.
• Any pest fish that are captured should not be released back into the stream.
APPENDIX E – PAGE 2 APPENDIX E – FISH RESCUE METHODOLOGY Karori Stream Main Outfall Pipeline Maintenance – Global Consent – August 2015
Description Responsibility
• Any fish that are captured should be identified and recorded in the NZ Freshwater fish database, including general observations (e.g. a range of size classes were present, or only big eels >400mm were found). Measurements of each fish is not required.
2.0 Temporary Diversion of Stream Flow to Pipe
2.1 Immediately following the completion of the biota transfers, install a Contractor, dam upstream of the section to be temporarily piped and divert the Engineer stream flow from here into a 150mm diameter flexible pipe. This pipe will discharge back into the stream downstream of the section to be temporarily piped (thus isolating the section to be piped or realigned). Some form of scour protection (e.g., a geotextile fabric and flow spreader) will need to be installed where the piped flow returns to the stream channel.
• The use of a flexible pipe (rather than an open lined channel) will mean it will be easy to move the pipe as needed during the construction works.
2.2 Fish Relocation Plan: Within the first few hours of the initial flow Ecologist diversion to the temporary pipe (or diversion to permanent channel), undertake a check of the dewatered stream channel to see if there are any stranded fish or freshwater crayfish, capture any found and release them upstream of the channel works area as per instructions in 1.5 above.
• As a section is dewatered an observer equipped with appropriate tools *(nets/buckets etc) needs to be available to capture any stranded fish.
• The dewatered section needs to be checked on several occasions. • This checking needs to incorporate a physical search of large (and easily moved) substrate to check for aquatic fauna hiding underneath.
• Diversions should also be kept open at the bottom end in the hope that fish may (unlikely for most) swim out on their own as the section is dewatered and if possible this dewatering should be staged slowly.
2.3 Once flow in the dewatered channel has reduced (or within several Contractor / hours of this), install a dam at the downstream end of the temporary Engineer piped section (upstream of silt fence and piped flow outlet). This will isolate the section of channel to be temporarily piped (or diverted to the new constructed channel) from the downstream section, and collect any silt released.
APPENDIX E – PAGE 3 APPENDIX E – FISH RESCUE METHODOLOGY Karori Stream Main Outfall Pipeline Maintenance – Global Consent – August 2015
Description Responsibility
2.4 Undertake repair/maintenance works in and around dewatered Contractor / streambed once Project Ecologist has given the go ahead. Engineer
3.0 Diversion Of Stream Flows To A New Channel
3.1 When the new diversion channel is adequately stabilised (*see note Contractor / below), arrange with Ecologist to undertake fish rescue (and follow Engineer / methodology in items 2.1 to 2.4). Start with the downstream section Ecologist first. If used to divert flows away from the works area, the temporary pipe will be removed on completion of works.
• Ensure no rain is forecast for the day and the days following the connection of flow to the new channel.
• Obtain GWRC Approval to diversion works in advance. • * A permanent diversion channel should be created to be as natural as possible – appropriate to existing in-stream environment (e.g. incorporate riffles runs and pools, with a variety of depths/flows in a new channel that replaces this type of in-stream environment) to create an environment similar to the original area.
• On completion of item 2.4 (maintenance and repair works), proceed as follows:
3.2 Remove the downstream dam from the active stream channel, then Contractor remove the diversion pipe and then remove upstream dam and the upstream and downstream silt fences
3.3 Install plug into channel upstream of diversion. Then follow process Contractor for 3.2. Removal of pipe will allow flow to enter the new channel (prevented flowing downstream by plug).
3.4 Inspection, Modifications and Final Sign off etc. Ecologist
APPENDIX E – PAGE 4 Karori Main Outfall Pipeline Management & Monitoring Plan
APPENDIX F
Approved Amendments to this MMP to be Recorded Here Date Summary of Amendment Made Details of GWRC Approved Document Attached