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Mt Eden Enabling Works Contamination Delivery Work Plan

CRL-MTE-RME-LKA-PLN-800020

Revision: 001 Date: December 2019

Contamination Delivery Work Plan

Mt Eden Enabling Works Contamination Delivery Work Plan CRL-MTE-RME-LKA-PLN-800020

This document is uncontrolled when printed. This document should be printed in colour

Revision Status Revision

Date

Version details

Prepared By

Approved By

Rev A00

27/9/2019

Draft for Community Liaison Group and Mana Whenua

Elyse LaFace

Peter Roan

Rev A01

13/11/2019

Draft for Auckland Council and Independent Peer Review

Elyse LaFace

Peter Roan

Rev 000

03/12/2019

Final for Submission

Elyse LaFace

Peter Roan

Rev 001

18/12/2019

Final with update following Auckland Council review

Elyse LaFace

Peter Roan

Approval Status Name/Title

Signature

Date

Prepared by:

Elyse LaFace Senior Environmental Specialist

18/12/2019

Reviewed by:

Lean Phuah Senior Contaminated Land Specialist

18/12/2019

Approved by:

Peter Roan Consenting Lead â€“ Link Alliance

18/12/2019

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Contamination Delivery Work Plan

Table of contents Abbreviations ................................................................................................ 5 1. Introduction ............................................................................................. 6 1.1

Overview of CRL works in Mt Eden ................................................................................ 6

1.2

Purpose of the Contamination DWP............................................................................... 7

1.3

Relevant conditions....................................................................................................... 7

1.4

Sustainability .............................................................................................................. 13

1.5

Contamination DWP review and updates ..................................................................... 13

1.6

Contamination DWP author......................................................................................... 13

2. Project description ................................................................................. 14 2.1

Construction Methodology .......................................................................................... 14

2.2

Site description ........................................................................................................... 14

3. Summary of contamination assessment ................................................. 15 3.1

Overview .................................................................................................................... 15

3.2

Geology and hydrogeology .......................................................................................... 15

3.3

Soil quality .................................................................................................................. 15

3.4

Groundwater quality ................................................................................................... 16

4. Roles and responsibilities....................................................................... 17 5. Contamination management ................................................................. 18 5.1

Overview .................................................................................................................... 18

5.2

Excavation of contaminated soil .................................................................................. 18

5.2.1.

Additional requirements for asbestos contaminated soils ........................................... 18

5.3

Soil material classification ........................................................................................... 21

5.4

Spoil disposal .............................................................................................................. 22

5.5

Transportation of spoil ................................................................................................ 22

5.6

Water management .................................................................................................... 23

5.7

Dust Management....................................................................................................... 23

5.8

Odour management .................................................................................................... 24

5.9

Sampling and testing ................................................................................................... 24

5.10 Imported material requirements ................................................................................. 25 5.11 Sealing excavation service trenches ............................................................................. 25

6. Health and safety contamination procedures......................................... 27 6.1 Page 3

Overview .................................................................................................................... 27

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Contamination Delivery Work Plan 6.2

General safety requirements and training .................................................................... 27

6.3

Control measures ........................................................................................................ 28

6.4

Identification of hazards .............................................................................................. 28

6.5

Identification of new hazards ...................................................................................... 29

6.6

Hazard mitigation procedures...................................................................................... 29

6.6.1.

Dust inhalation .............................................................................................................. 29

6.6.2.

Vapour and gas inhalation ............................................................................................ 29

6.6.3.

Dermal contact and ingestion ....................................................................................... 29

6.7

Personal protective equipment.................................................................................... 30

6.8

Communication plan ................................................................................................... 30

6.9

Incident reporting ....................................................................................................... 30

7. Contingency measures ........................................................................... 31 7.1

Unexpected discovery of contamination ...................................................................... 31

7.2

Water discharges ........................................................................................................ 32

8. Works summary/validation reporting .................................................... 33 Appendix A: ISCA Requirements .................................................................. 34 Appendix B: Staging Drawings ..................................................................... 36 Appendix C: Record of CLG, IPR and Auckland Council Comments................ 37 C-1: Community Liaison Group (CLG) Comments .................................................................... 37 C-2: Independent Peer Review (IPR) Comments ..................................................................... 37 C-3: Auckland Council Comments........................................................................................... 37

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Contamination Delivery Work Plan

Abbreviations Acronym

Meaning

ACM

Asbestos-containing material

ACoP

Approved Code of Practice: Management and Removal of Asbestos (WorkSafe NZ, Sept 2016).

ACZ

Active Construction Zone

AF/FA

Asbestos fines/Friable asbestos

ANZECC Guidelines

Australian and New Zealand Environment Conservation Council Guidelines for Fresh and Marine Water Quality (2000)

AUP

Auckland Unitary Plan â€“ Operative in Part

AVF

Auckland Volcanic Field

BaPeq

Benzo(a)pyrene equivalence

bgl

Below ground level

CCP

Communications and Consultation Plan

CEMP

Construction Environmental Management Plan

CLG

Community and Business Liaison Group

CLS

Contaminated Land Specialist (also referred to as a Contaminated Land Professional).

CRL

City Rail Link

CRLL

City Rail Link Limited

CSA

Construction Support Area

DWP

Delivery Work Plan

ECBF

East Coast Bays Formation

ESCP

Erosion and Sediment Control Plan

ESM

Environmental and Sustainability Manager

HSO

Health and Safety Officer

IPR

Independent Peer Reviewer

IS Rating

Infrastructure Sustainability Rating

ISCA

Infrastructure Sustainability Council of Australia

MfE

Ministry for the Environment

NAL

North Auckland Line

NES Soil

Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011

PAH

Polycyclic aromatic hydrocarbons

PPE

Personal protective equipment

SCS

Coil contaminant standards

SQEP

Suitably qualified and experience practitioner; in this context as defined in the NES Soil

SVR

Site Validation Report

Tauranga Group

TBM

Tunnel boring machine

TPH

Total petroleum hydrocarbons

WDQMP

Water Discharge Quality Monitoring Programme

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Contamination Delivery Work Plan

Introduction

The City Rail Link (CRL) project comprises the construction, operation and maintenance of a 3.4 km underground passenger railway, running between Britomart Station and the North Auckland Rail Line (NAL) in the vicinity of Mt Eden Station. The CRL involves the construction of two new underground stations at Aotea and Karangahape, and a redeveloped station at Mt Eden (refer to Figure 1-1). The design and construction of the CRL infrastructure between Aotea and Mt Eden Stations is being delivered by the Link Alliance. This Contamination Delivery Work Plan (C DWP) has been prepared in relation to the Mt Eden Enabling Works (“the Project”).

Figure 1-1: CRL Route and Location

1.1 Overview of CRL works in Mt Eden The CRL works in the Mt Eden area involve the construction of the southern section of the tunnel structures and the tie-in to the existing NAL, including the construction of the redeveloped Mt Eden Station. The Mt Eden Active Construction Zone (ACZ) and Construction Support Area (CSA) is generally located between Nikau Street to the north, State Highway 1 (SH1) to the east, Dominion Road to the west and the existing NAL to the south. The works in this area include: • • • • • Page 6

Construction of an underground grade separation structure near Mt Eden Station; A new Mt Eden Station building incorporating passenger linkages; Modifications to the existing Mt Eden Station platforms; Road over rail bridges at Mt Eden Road, Normanby Road and Ruru Street with sections of road realignment; Grade separation structures for the existing and new rail lines to pass-over and connect with each other;

| Mt Eden Enabling Works

Contamination Delivery Work Plan • •

Pedestrian and cyclist bridge structures at Fenton Street and Porters Avenue; and New road linkages within the reinstated area post-construction.

Given the nature and scale of CRL works in Mt Eden, construction will be undertaken in a staged manner. This C DWP only relates to the first stage of these works, the Mt Eden Enabling Works, as described in Section 2 below. Following completion of the Mt Eden Enabling Works, works in this area will involve: •

•

Main construction works – these works will include: Tunnel Boring Machine (TBM) operations, structure construction and waterproofing/tanking for cut and cover tunnels, utilities installation, retaining wall for Ruru street extension, construction of the rail line tie-ins including junctions and grade separation structures, realignment of the existing Western Line including platform reconstruction, grade separation of Normanby Road, pedestrian / cyclist bridges at Fenton and Porters, construction of the new station buildings. The Main Works will be undertaken from Mid 2020 through to 2024. Public realm reinstatement – these works will involve establishing the final finishings and features that will comprise the completed Mt Eden Station and surrounds and will likely to be undertaken from 2021 to first quarter-2024.

1.2 Purpose of the Contamination DWP This C DWP has been prepared to identify measures that will be implemented to mitigate and manage the potential adverse effects relating to contaminated land during the Mt Eden Enabling Works. The objectives of the DWP are: • •

To avoid, remedy or mitigate the adverse effects of the construction on human health, which may result from the disturbance of contaminated materials during construction; and To minimise discharges to land or water from contaminated soils from within the footprint of the Mt Eden Enabling Works.

The CRL designation (conditions 57 and 58) requires the preparation of a C DWP while conditions 131150 of the discharge permit (R/REG/2016/1895) and land use consent (R/LUC/2016/1890) require a Contaminated Soils Management Plan (CSMP). These two separate document requirements have been combined and are addressed in this single C DWP. This C DWP has been prepared by the Link Alliance in consultation with the Mt Eden Community and Business Liaison Group (CLG) and reviewed by Independent Peer Reviewer (IPR) prior to submission to Auckland Council (as per designation conditions 7 and 11, and condition 19 of the resource consent conditions). This C DWP has been prepared in general accordance with Ministry for the Environment (MfE) Contaminated Land Management Guideline No. 1: Reporting on Contaminated Sites in New Zealand (revised 2011), and forms part of the Construction Environmental Management Plan (CEMP) for the Mt Eden Enabling Works.

1.3

Relevant conditions

Table 1-1 identifies the designation and resource consent conditions relevant to this C DWP and where they are addressed in the document. Page 7

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Contamination Delivery Work Plan Table 1-1: Contamination-related conditions and location in Plan

Condition No.

Condition

Relevant section of DWP

CRL Designation Conditions 57.1

A Contamination DWP shall be prepared to manage the adverse effects relating to contaminated land during the construction of the City Rail Link or any part of it.

This C DWP

57.2

The objective of the Contamination DWP is to avoid, remedy or mitigate the adverse effects of construction on human health which may result from the disturbance of contaminated materials during construction.

This C DWP

57.3

To achieve the above objective the following shall be included in the Contamination DWP and implemented as required: a

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Health and safety plan that addresses: (i)

Worker safety in relation to hazardous substances; and

(ii)

Worker training with regard to handling hazardous substances, identifying potentially contaminated soil/material, and notification procedures for discovery of contamination;

Section 6.2

Procedures for how erosion and sediment control, storm water, dust, and odour control measures will manage the removal of contaminated soil/material;

Section 5

Procedures for contaminated soil classification, management and disposal of contaminated soil/material;

Section 5.3 and 5.4

Where any trenches/excavations during civil works are to be sealed as a result of contamination and how this is to be recorded;

Section 5.12

How and which work areas are to be restricted to authorised personnel only and procedures to limit the presence of ignition sources in these areas (e.g. no smoking within or adjacent to construction area, no welding or open flames near areas with high concentrations of hydrocarbon contamination);

Section 6.2 and 6.6.2

Procedures for the monitoring and management of the removal of contaminated soil/material by a suitably qualified environmental specialist;

Sections 4, 5.3 and 5.4

How the placement of re-used contaminated soil/material will be recorded and tracked;

Section 5.4

Where areas for stockpiling and storing contaminated soil/material will be established on the construction site and the procedures for managing the containment of the contaminated soil / material in these areas;

Section 5.2

Cross references to the specific sections in the Communication and Consultation Plan which detail how the general public are to be communicated with on the management of the adverse effects relating to the removal of contaminated soil/material.

Section 6.8

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Contamination Delivery Work Plan Condition No.

Condition

Relevant section of DWP

58.1

At the completion of construction works a validation report will be prepared in accordance with any Ministry for the Environment guidelines and submitted to the Auckland Council Consent Monitoring officer documenting the management of soil and evidence of appropriate disposal. The validation report shall include a record of all analytical results, volumes, tip dockets, and any incidents or complaints and how these were addressed. The validation report shall also identify any areas which need on-going monitoring and management by the Requiring Authority.

Section 8

Resource consent conditions 131

At least 20 days prior to the commencement of construction (earthworks), the Consent Holder shall provide a Contaminated Soils Management Plan (CSMP) to the Council (Team Leader Central Monitoring) for certification. The CSMP shall be prepared by a Contaminated Land Professional in accordance with the Contaminated Land Management Guidelines, No.1 Reporting on Contaminated Sites in New Zealand, Ministry for the Environment (revised 2011).

This C DWP

132

The Consent Holder shall request that Council (Team Leader Central Monitoring) provide a determination to the Consent Holder, in writing, within 10 working days of receipt of the CSMP, whether the CSMP can be certified as per the requirements of the Condition 134.

Sections 4 and 9

133

No earthworks shall commence until:

134

Certification is provided from the Council (Team Leader Central Monitoring) that the CSMP satisfactorily meets the requirements of Schedule 13 (A4) of the ACRP:ALW, and

Section 4

All measures identified in that plan as being required to be established prior to the commencement of earthworks have been established.

Section 5.1

The CSMP shall address the following matters: a

The areas within the project site designated for the excavation works, including depths and extent of the proposed works, and an updated map showing the land disturbance activity areas;

Section 2 and Appendix B

Excavation, management, and disposal procedures for soil, sediment, dust, surface run-off water, perched groundwater, and groundwater, if encountered;

Section 5

Temporary containment, treatment, and testing procedures for any water getting in contact with the contaminated material if the disposal option is to the stormwater system or the marine environment is considered;

Section 5.6

Contingency measures for unexpected discovery of contamination;

Section 7

Proposed sampling and analysis, if applicable; and

Section 5.10

Any proposed works summary reporting.

Section 8

Advice Note: The Council acknowledges that the CSMP is intended to provide flexibility for the management of the works and contaminant discharge. Accordingly, the Plan may need to be further updated. Any updates must be limited to the scope of this consent and consistent with the conditions of this consent.

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Section 9

Contamination Delivery Work Plan Condition No.

Condition

Relevant section of DWP

135

The Consent Holder shall notify the Council (Team Leader Central Monitoring) at least two working days prior to any earthworks activity on the site and provide the following details:

Section 5.1

Name and telephone number of the project manager and the site owner;

Site address to which the consents relate;

Activity to which the consents relate; and

Expected duration of the works.

136

All disturbance of contaminated and potentially contaminated soil shall be carried out in accordance with the certified CSMP required by Condition 131 and any changes to the plan shall be submitted to the Council (Team Leader Central Monitoring) for certification prior to the change being implemented.

This C DWP and Section 9

137

The Consent Holder shall ensure that all disturbance of contaminated soil shall be supervised by a suitably qualified and experienced Contaminated Land Professional, whose responsibilities shall include making sure that the soil management and disposal procedures, the contingency measures outlined in the certified CSMP required by Condition 131, and all relevant consent conditions are adhered to.

Section 4

138

The Consent Holder shall ensure that regular inspections of the works area shall be carried out by a suitably qualified and experienced Contaminated Land Professional. These inspections shall be documented and the relevant records retained and provided to Council (Team Leader Central Monitoring) in the Site Validation Report (SVR) required by Condition 149.

Section 4 and Section 8

139

The Consent Holder shall manage all soil disturbance works to minimise any discharge of debris, soil, silt, sediment or sediment-laden water from the subject site to either land, stormwater systems or the receiving marine environment. The implementation of erosion and sediment controls shall be in accordance with the ESCP required by Condition 53.

Section 5

Advice Note: Measures such as covering the excavations overnight and during heavy rainfall, diverting overland flow around the works area, and appropriate treatment of any water collected in an excavation prior to the disposal may be required to comply with this condition.

140

The Consent Holder shall manage all soil disturbance works to avoid the potential for cross-contamination of materials to occur, in particular, movement of contaminated soil around the site and/or deposition of contaminated soil on other parts of the site shall be avoided. Where soils are identified for off-site disposal, they shall be loaded directly for removal, where possible, and all material shall be covered during transportation off site.

Section 5.2-5.5

141

To minimise the spread of contaminated material, any temporary stockpiles of the excavated contaminated material shall be located within the catchment of erosion and sediment controls for the site. All stockpiles shall be covered with either polythene or an equivalent impermeable material when the site is not being worked and during periods of heavy rain.

Section 5.2

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Contamination Delivery Work Plan Condition No.

Condition

Relevant section of DWP

142

At all times, dust shall be controlled in accordance with the publication titled Good Practice Guide for Assessing and Managing the Environmental Effects of Dust Emissions, Ministry for the Environment (2001).

Section 5.7 and the Air Quality Management Plan (AQMP) prepared for the Mt Eden Enabling Works.

143

Excess soil or waste materials removed from the subject site shall be deposited at a disposal site which holds a consent to accept the relevant level or type of contamination.

Section 5.4

Advice note: Where it can be demonstrated that the soil has been fully characterised and meets the definition of ‘clean fill’ material in Section J1 of the Auckland Unitary Plan (Operative in Part), the removal of such material to a consented disposal facility is not required. In such circumstances, a record of the location, depth, and volume of the material removed as ‘clean fill’ should be kept for the purpose of being included in the SVR required by Condition 149).

144

The Consent Holder shall implement the procedures for the management, treatment, temporary containment, testing, and disposal of groundwater and surface run-off water via the stormwater system in accordance with the report titled Auckland City Rail Link: Resource Consent Package 2: Aotea Station to North Auckland Line Construction and CRL Operation: Draft Erosion & Sediment Control Management Plan, dated 13 May 2016, prepared by Aurecon New Zealand Limited, and provided with the application.

Updated Erosion and Sediment Control Plan (ESCP) has been prepared for the Mt Eden Enabling Works.

145

Any perched groundwater, or surface run-off water, encountered within the excavation area requiring removal shall be considered as potentially contaminated, and shall either:

Section 5.6 and Water Discharge Quality Monitoring Programme (WDQMP) included within the Flocculation Treatment Management Plan (FTMP) prepared for the Mt Eden Enabling Works.

146

Be disposed of by a licensed liquid waste contractor; or

Pumped to sewer, providing relevant permits are obtained; or

Discharged to the stormwater system, provided testing demonstrates compliance with 50 times the Australian and New Zealand Environment Conservation Council (ANZECC) Guidelines for Fresh and Marine Water Quality (2000) for the protection of 95 percent of marine water species, and is free from petroleum hydrocarbons.

Where contaminants which have not been anticipated by the application are identified, works in the area containing the unexpected contamination shall cease until the contingency measures outlined in the certified CSMP required by Condition 131 have been implemented, and have been notified to the Council (Team Leader Central Monitoring). Any unexpected contamination encountered during the works and contingency measures implemented shall be documented in the Site Validation Report required by Condition 149. Advice Note: In accordance with Condition 146, any unexpected contamination may include separate phase hydrocarbons, contaminated soil, perched water or groundwater. The Consent Holder is advised that where unexpected contamination is significantly different in extent and concentration from that anticipated, handling the contamination may be outside the scope of this consent. Advice should be sought from the Council (Team Leader Central Monitoring) prior

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Section 7

Contamination Delivery Work Plan Condition No.

Condition

Relevant section of DWP

to carrying out any further work in the area of the unexpected contamination to check this is within the scope of this consent.

147

All imported fill shall: a

Comply with the definition of clean fill material in Section J1 of the Auckland Unitary Plan (Operative in Part); and

Be solid material of an inert nature; and

Not contain hazardous substances or contaminants above recorded natural background levels of the receiving site.

Section 5.11

Advice Note: Background contamination levels for the site receiving clean fill can be found in Technical Publication No. 153, Background concentrations of inorganic elements in soils from the Auckland Region, Auckland Regional Council (2001).

148

All sampling and testing of contamination on the site shall be overseen by a suitably qualified and experienced Contaminated Land Professional. All sampling shall be undertaken in accordance with Contaminated Land Management Guidelines, No.5 – Site Investigation and Analysis of Soils, Ministry for the Environment (revised 2011).

Section 5.10

Advice Note: All testing and analysis should be undertaken in a laboratory with suitable experience and ability to carry out the analysis. For more details on how to confirm the suitability of the laboratory please refer to Contaminated Land Management Guidelines, No.5 – Part 4: Laboratory Analysis, Ministry for the Environment (revised 2011).

149

Within three months of the completion of earthworks on the site, the Consent Holder shall provide a Site Validation Report (SVR) to the Council (Team Leader Central Monitoring). The SVR shall be prepared by a suitably qualified and experienced Contaminated Land Professional in accordance with the Contaminated Land Management Guidelines, No.1 - Reporting on Contaminated Sites in New Zealand, Ministry for the Environment (revised 2011).

Section 8

150

The SVR required by Condition 149 shall address the following matters:

Section 8

Page 12

A summary of the works undertaken, including a statement confirming whether the excavation of the site has been completed in accordance with the certified CSMP required by Condition 131;

The location and dimensions of the excavations carried out, including the relevant site plan;

A summary of soil, groundwater, and surface run-off water testing undertaken, if applicable, including tabulated analytical results, and interpretation of the results in the context of the Contaminated Land Rules of the Auckland Unitary Plan (Operative in Part);

Copies of the disposal dockets for the contaminated soil and ‘clean fill’ material removed from the site;

Records of any unexpected contamination encountered during the works and contingency measures undertaken, if applicable;

Details regarding any complaints and/or breaches of the procedures set out in the certified CSMP required by Condition 131 and the conditions of this consent;

Results of testing, if required, of any spoil disposed offsite; and

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Contamination Delivery Work Plan Condition No.

Condition h

1.4

Relevant section of DWP

Results of testing of any imported fill material to ensure compliance with the definition of clean fill material in Section J1 of the Auckland Unitary Plan (Operative in Part).

Sustainability

The Link Alliance is seeking an Infrastructure Sustainability Council of Australia (ISCA) Infrastructure Sustainability (IS) Rating. Further details can be found in the CEMP and Sustainability Rating Management Plan. Project sustainability requirements that relate directly to this C DWP are included in Appendix A. These requirements are imbedded within the Delivery Work Plans and management plans for the Project to ensure that sustainability is a key focus and ‘the way we do things’. In some cases, the IS requirements and sustainability goals enhance the designation and consent requirements.

1.5

Contamination DWP review and updates

This C DWP is a live document that will be reviewed and updated at least annually, or as a result of a material change to Mt Eden Enabling Works, or to address unforeseen adverse contamination effects arising from construction, or unresolved complaints. Refer to the CEMP for further detail on the review and updating process.

1.6

Contamination DWP author

This C DWP has been prepared and reviewed by Contaminated Land Specialists (CLS). Elyse LaFace is a Senior Environmental Scientist at Tonkin & Taylor Ltd (T+T) and is the author of this C DWP. Elyse has a Master of Environmental Management, Bachelor of Science with Honours degree in Biology and Geology and a Diploma in Engineering (Civil). She has more than 10 years’ professional experience in the environmental practice area. Lean Phuah is the Discipline Director - Science at T+T and has reviewed this C DWP. Lean has a Bachelor of Civil Engineering degree from the University of Canterbury and is a chartered professional engineer (CPEng) working in the environmental practice area and certified environmental practitioner (CENVP(SC)). She has more than 20 years’ experience in investigations, assessment, management and reporting of contaminated sites. Elyse and Lean are suitably qualified and experienced practitioner (SQEP) under the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (NES Soil).

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Contamination Delivery Work Plan

Project description

In order to launch the TBM and commence construction of the CRL tie-ins to the NAL, a range of ‘enabling’ works are proposed, which are the subject of this C DWP. These works are described in detail in the CEMP. In summary, the Mt Eden Enabling Works involve: • • •

•

• • • •

Continuation of the demolition and clearance of the Mt Eden CSA (these works are authorised under the Mt Eden Demolitions Outline Plan) Set up of a temporary site office, which is anticipated to be a 2-3 storey modular building (likely made up of containers) located in the western extent of the CSA. Piling and excavation associated with the preparation of the portal. This will involve the demolition of the redundant stormwater shaft located in the portal area; the installation of bored piles and associated works (ground anchors and shotcrete) to support the excavation face; and removal of spoil. Bulk excavation to form what will become the rail trenches/cut and cover tunnels, which will also provide a ramp for the TBM to be manoeuvred into position. The excavation will encounter basalt, which is to be blasted in order to expediate the works and minimise the amount of rock-breaking required. In places, softer ground conditions are anticipated to be encountered, which may require the use of sheet piles. Local mined tunnelling to facilitate the TBM launch. Construction of the additional Mt Eden Road bridge (north of the existing bridge), including temporary diversion of shallow utilities in this location. Construction of the Ruru Street bridge, including diversion of the Huia 2 watermain in this location. Temporary and permanent utility diversions (such as water, wastewater, stormwater, Vector overhead cables and ducting, gas and communications) along Fenton Street, Porters Avenue, Haultain Street and Wynyard Street to provide adequate clearance between the Huia 2 watermain and NAL, associated retaining walls, and the proposed Fenton Street pedestrian bridge.

2.1 Construction methodology The Project will be divided into stages as described in the CEMP.

2.2 Site description The project site is predominantly located to the north of Mt Eden Station in Eden Terrace, as well as along Mt Eden Road (north of the existing Mt Eden Road bridge), Fenton Street, Porters Avenue, Haultain Street and Wynyard Street. The area to the north of Mt Eden Station is generally bounded by the NAL (south) Ngahura Street (west) Nikau Street (north) and Flower Street (east). The properties within the works area were purchased by Auckland Transport for the purposes of the CRL Project and are currently under CRLL’s management.

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Contamination Delivery Work Plan

Summary of contamination assessment 3.1 Overview

Contamination investigations conducted for the CRL project to support obtaining the necessary planning approvals for works in the Mt Eden area are documented in the following reports. • • •

City Rail Link: Contaminated Land Assessment July 2012, prepared by AECOM; Auckland City Rail Link: Aotea Station to North Auckland Line Construction and CRL Operation Contaminated Land Assessment May 2016, prepared by Golder Associates; and Auckland City Rail Link: Aotea Station to North Auckland Line Construction and CRL Operation Contaminated Land Assessment – South Pacific Timber July 2016, prepared by Golder Associates.

The contaminated land assessments undertaken for the CRL works in the Mt Eden area comprised an assessment of soil and groundwater. For accessibility and logistical reasons, the soil and groundwater investigations did not necessarily target specific locations but were positioned to provide an overview of potential ground contamination constraints.

3.2 Geology and hydrogeology The geology in the CRL Mt Eden Enabling Works area comprise the following: • •

• •

Fill – surficial fill variably comprised of clays, silts, sands and rubble. Fill is typically up to approximately 4 m bgl. The composition and thickness varies irregularly; Tauranga Group (TA) – alluvium, typically composed of clayey to sandy silts. These sediments are derived predominantly from erosion of East Coast Bays Formation (ECBF). Some areas of very soft TA and high organic content TA have been encountered; ECBF – a sequence of sandstone beds with interbedded mudstone and siltstone layers; and Auckland Volcanic Field (AVF) – three distinct lithologies present; ash, tuff and basalt lava.

Fill is typically underlain by TA/ECBF but within the works area there are areas underlain by AVF. Several groundwater monitoring wells have been installed in the vicinity of the works area. Groundwater levels indicate the presence of perched groundwater recorded between 0.5 m and 2 m bgl. Additional groundwater details are included within the Groundwater and Settlement Monitoring and Contingency Plan (GSMCP) prepared for the Mt Eden Enabling Works.

3.3 Soil quality Intrusive investigation work has been undertaken on public land and within road reserves around the CRL project alignment and have not specifically assessed potential contamination on private properties. Soil quality testing undertaken in and around the Mt Eden Enabling Works area has largely focused on potential contaminants of interest likely to be associated with the urban land use. More targeted investigations were also undertaken at the South Pacific Timber site (21 Ruru Street) which makes up the south-western portion of the Mt Eden Enabling Works area. The South Pacific Timber site was formerly part of a railway marshalling yard until the tracks through the area were removed in the 1960s to 1970s. South Pacific Timber had leased their site for approximately 20 years sealing the site with concrete on occupation. The South Pacific Timber site has been used for timber storage and distribution; timber treatment activities have not been undertaken at the site. Page 15

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Contamination Delivery Work Plan Soil analysis comprised the following common contaminants considered appropriate for fill with unknown origin and road infrastructure: • • • •

Asbestos (within the test pits at the South Pacific Timber site only); Metals; Polycyclic aromatic hydrocarbons (PAH); and/or Total petroleum hydrocarbons (TPH).

The NES Soil regulations provide a set of chemical specific soil contaminant thresholds that define an adequate level of protection for human health for a range of differing land-uses in New Zealand (referred to as soil contaminant standards or SCS). For the Mt Eden Enabling Works, the NES SCS for commercial/industrial land use has been adopted. All results complied with the adopted NES SCS, with the exception of the benzo(a)pyrene equivalence (BaPeq) concentrations in several shallow fill samples. Asbestos in soils was also investigated within the 11 test pits advanced in accessible areas of the South Pacific Timber site. Asbestos was detected in shallow fill in 2 of 16 samples. The samples positive for asbestos were logged with demolition rubble containing glass. These samples were re-analysed to determine the concentration of asbestos in the samples. The NZ Asbestos in Soil Guidelines 1 provides criteria of 0.05% weight/weight (w/w) ACM and 0.001% w/w for AF/FA for commercial/industrial land use. Asbestos concentrations in one of the samples were reported as <0.001% weight/weight (w/w) for both ACM and combined asbestos fines (AF) and friable asbestos (FA). For the other sample, a concentration was unable to be determined as the single bundle of fibres identified had been removed for identification in the first analysis and unable to be recovered. Results in several samples exceeded the Auckland Council criteria for discharges to the environment (previous and current adopted criteria). Copper, lead, zinc and BaPeq concentrations within shallow fill exceeded the discharge criteria. Fill material also exceeded the published background concentrations for volcanic and non-volcanic soils in Auckland as described in the Auckland Regional Council Technical Publication 153 – Background Concentrations of Inorganic Elements in Soils from the Auckland Region (TP153). Fill material will be removed during the works and will require appropriate disposal (refer Section 5.4).

3.4 Groundwater quality Groundwater information is available for a number of locations on public land and within road reserves along the CRL project alignment. Groundwater quality in and around the Mt Eden Enabling Works area indicates elevated concentrations above ANZECC 95% marine trigger values for chromium, copper, lead and zinc. Concentrations, particularly of total copper, were found to also exceed 50 times ANZECC 95% marine trigger values. Groundwater will be encountered during the Mt Eden Enabling Works. Groundwater and surface water will require management prior to disposal (refer Section 5.6 and the ESCP prepared for the Mt Eden Enabling Works).

BRANZ, 2017, New Zealand Guidelines for Assessing and Managing Asbestos in Soil Page 16 | Mt Eden Enabling Works 1

Contamination Delivery Work Plan

Roles and responsibilities

Certification of this C DWP is required from the Council (Team Leader Central Monitoring) and must be received prior to the commencement of earthworks. The certified C DWP shall be readily available on site at all times. The provisions of the C DWP shall be outlined to all parties undertaking works during the Mt Eden Enabling Works during the site inductions (refer Section 6.2). Each person involved in the works has equal responsibility to avoid, remedy or mitigate adverse environmental and human health effects. The Construction Manager for the Mt Eden Enabling Works is responsible for the implementation of the CEMP and associated management plans/DWPs (including this C DWP). An Environmental and Sustainability Manager (ESM) and CLS are to be appointed to support the Construction Manager. The ESM and CLS are to be involved in the lead up to and during works. The key responsibilities of the ESM and CLS with respect to this C DWP are summaries in Table 4-1 below. Table 4-1: Key roles and responsibilities associated with this Contamination DWP

Role

Responsibility

ESM

• Ensure the CEMP and associated management plans/DWPs (including this C DWP) are implemented and maintained; • Inspections auditing and checking of environmental management practices and procedures; • On site compliance with consent conditions, management plans/DWPs, other requirements and tracking compliance information; • Attendance at compliance meetings with Auckland Council Compliance and Monitoring Officers; • Coordinate review and update of CEMP and associated management plans/DWPs as required; • Facilitate and oversee environmental monitoring and reporting; • Update and maintain the environmental portion of the Project Risk Register; • Facilitate the training of all staff and subcontractors on environmental and sustainability requirements; • Reporting on environmental and sustainability key performance indicators; and • Undertaking environmental incident investigations.

CLS

• Supervise the management of ground and water contamination and verify the implementation of the procedures and the contingency measures outlined in this C DWP (refer Section 7) and the relevant consent and designation conditions; • Complete regular inspections which shall be documented, and the relevant records retained and provided to Council (Team Leader Central Monitoring) as required; • Provide advice in regard to potentially contaminated materials as required during works; • For any required soil testing, provide guidance of the analytical testing required and provision for completing the testing. Work may be delegated to a more junior CLS, as appropriate; and • Prepare the SVR at completion of disturbance works.

Refer to the CEMP for a detailed description of key management roles in relation to the overall environmental management during the Mt Eden Enabling Works.

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Contamination management 5.1 Overview

This section details the procedures for the management of contaminated media (soil, groundwater and surface water) during the Mt Eden Enabling Works. It includes control measures for reducing human exposure to contaminated soils and water and minimise contaminated discharges to air, land and/or water. These measures must be established prior to commencing and maintained during earthworks associated with the Mt Eden Enabling Works. The Council (Team Leader Central Monitoring) is to be notified at least two working days prior to any of the earthworks.

5.2 Excavation of contaminated soil While the protocols below can be applied to all earthworks associated with the Mt Eden Enabling Works, contamination has only been identified within fill. The following is most relevant to disturbance within fill: • • •

•

Erosion and sediment controls shall be implemented in accordance with the ESCP prepared for the Mt Eden Enabling Works before earthworks commence; Excavated spoil shall be placed directly into a truck for immediate off-site disposal, where practicable; Excavated spoil classified as contaminated fill (refer Section 5.3) retained on site as part of contingency storage shall be placed within erosion and sediment controls and covered when not being worked and weather conditions dictate so as to minimise dust and runoff (additional details for management of stockpiles detail in the Air Quality DWP (AQ DWP) prepared for the Mt Eden Enabling Works); Spillages of soil during placement in trucks shall be cleaned up as soon as practicable following the spillage. Spillages shall not be left unattended as contaminated soil could be trafficked by trucks and transported off-site; and The earthworks shall be observed by the CLS. If unexpected contamination is encountered during works, the works shall cease in the immediate vicinity and the procedures documented in Section 7 of this C DWP shall be followed.

5.2.1. Additional requirements for asbestos contaminated soils The management of asbestos in soils is regulated under the Health and Safety at Work (Asbestos) Regulations 2016 (Asbestos Regulations). In order to help achieve compliance with the Asbestos Regulations, WorkSafe New Zealand has prepared an Approved Code of Practice (ACoP): Management and Removal of Asbestos (September 2016). The ACoP refers readers to the NZ Asbestos in Soil Guidelines. The key requirements of the Asbestos Regulations and ACoP are that works involving asbestos contaminated soils must be undertaken with appropriate asbestos controls in place and that contaminated soil removed from site must be taken to an approved disposal site. Table 5-1 provides a summary of the controls indicated in the NZ Asbestos in Soil Guidelines for different concentrations of AF/FA and ACM. The results of the limited asbestos in soil investigations undertaken specifically within the South Pacific Timber site indicate the presence of trace asbestos in fill soils. Disturbance of surficial fill material on the South Pacific Timber site shall be undertaken, as a Page 18

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Contamination Delivery Work Plan minimum, as Unlicensed Asbestos Works as defined in NZ Asbestos in Soil Guidelines, unless further testing is undertaken to justify that the controls are not required. If a higher concentration of asbestos fibres is detected as part of any additional testing, then the relevant level of controls outlined in Table 5-1 shall be implemented. This C DWP is to be reviewed and updated to confirm the controls to be implemented on receipt and review of any additional soil results. Table 5-1: Summary of asbestos requirements as detailed in the NZ Asbestos in Soil Guidelines

Scenario

Class A works – non-friable

Class B works – non-friable

Asbestos-related works

Unlicensed asbestos work

>0.1% w/w AF+FA in soil

>0.01% w/w AF+FA in soil

>0.001% w/w AF+FA in soil

≤0.001% w/w AF+FA in soil

>1% ACM

>0.01 % w/w ACM

<0.01% w/w ACM

Additional documentation/ notification requirements

Asbestos removal control plan and WorkSafe notification for asbestos removal

No additional notification required

Oversight by a licensed removalist

Required

Not required

Personal protective equipment (PPE)

Disposable coveralls rated type 5, category 3, nitrile gloves, steel toe capped gumboots or safety footwear with disposable overshoes.

No asbestos-specific PPE as concentrations are unlikely to exceed trace levels in air.

Minimum respiratory protective equipment

Full-face P3 respirator with particulate filter.

Half-face P3 respirator with particulate filter.

Disposable P2 dust mask

No asbestos-specific requirements as concentrations are unlikely to exceed trace levels in air

Dust/asbestos fibre suppression

Water and polymer spray via localised points before and during works.

Water spray via localised points.

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Contamination Delivery Work Plan Scenario

Class A works – non-friable

Class B works – non-friable

Asbestos-related works

Unlicensed asbestos work

>0.1% w/w AF+FA in soil

>0.01% w/w AF+FA in soil

>0.001% w/w AF+FA in soil

≤0.001% w/w AF+FA in soil

>1% ACM

>0.01 % w/w ACM

<0.01% w/w ACM

Air monitoring

Air monitoring required

Air monitoring not required but can be undertaken depending on the site setting and to confirm that concentrations are below 0.01 f/ml

Air monitoring not required but can be undertaken depending on site setting to confirm that concentrations are below 0.01 f/ml

Air monitoring not required

Decontamination facilities

Dedicated wet decontaminatio n area or trailer. Consider powered and plumbed unit

Dedicated decontamination area and foot wash

Foot wash and used PPE collection area.

Vehicle (truck) protection

200 µm heavygauge polythene wrapped soil/lined trays and truck covered.

Truck lining/soil wrapping depends on the receiving landfill. All trucks should be covered.

Truck lining/soil wrapping depends on the receiving landfill. All trucks will be covered.

HEPA filter system fitted for all occupied vehicles filter replaced or clean down with HEPA vacuum cleaner post work

HEPA filter system fitted for all occupied vehicles where friable ACM on site (lagging, insulation, etc).

Standard air conditioning.

Visual assessment plus swab and air sampling inside the cab by an independent assessor

Visual assessment plus swab (if friable) by an independent assessor or independent competent person* or SQEP following brush and or wash down

Visual assessment by a competent person* or SQEP following brush and or wash down

Vehicle Washing Facilities

Finishing surfacing/cap

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No special finishing/cover requirements if soils are confirmed to meet health criterion (0.001% w/w). Otherwise: Hard cap - No depth limitation, no controls. Soft cap – at least 0.2 m and should be delineated by a permeable geotextile marker layers between the cap and underlying asbestos/contaminated material.

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Contamination Delivery Work Plan Scenario

Class A works – non-friable

Class B works – non-friable

Asbestos-related works

Unlicensed asbestos work

>0.1% w/w AF+FA in soil

>0.01% w/w AF+FA in soil

>0.001% w/w AF+FA in soil

≤0.001% w/w AF+FA in soil

>1% ACM

>0.01 % w/w ACM

<0.01% w/w ACM

If validation testing shows any soil at the base of any excavation contains asbestos, even at <0.001% w/w, the Asbestos Regulations require the location of these to be recorded in an asbestos management plan. * A competent person must meet the requirements of regulation 41(3) of the Asbestos Regulations. Ongoing management

5.3 Soil material classification The spoil generated as result of the Mt Eden Enabling Works will require off-site disposal. In the context of this C DWP, spoil generated shall be classified as per the following three categories to define disposal requirements: Cleanfill Cleanfill material is defined in the Auckland Unitary Plan – Operative in Part (AUP) as: Means natural material such as clay, gravel, sand, soil and rock which has been excavated or quarried from areas that are not contaminated with manufactured chemicals or chemical residues as a result of industrial, commercial, mining or agricultural activities. Excludes: • • • • • • • •

Hazardous substances and material (such as municipal solid waste) likely to create leachate by means of biological breakdown; Product and materials derived from hazardous waste treatment, stabilisation and disposal practices; Materials such as medical and veterinary waste, asbestos, and radioactive substances; Soil and fill material which contain any trace element specified in Table E30.6.1.4.2 at concentration greater than the background concentration in Auckland soils specified; Sulfidic ores and soils; Combustible components; More than 5 % by volume of inert manufactured materials (e.g. concrete, brick, titles); and More than 2 % by volume of attached biodegradeable material (e.g. vegetation).

Managed fill Managed fill comprises: • • •

•

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Soil containing metal contaminants above the published background concentrations in the Auckland region. Soil containing low level hydrocarbon compounds. Soil containing low level asbestos in soil concentrations (depending on disposal facility). o Note: there are currently no managed fill tip sites within the Auckland Region that can accept asbestos. Soil that does not contain hazardous substances or materials in the form of household and industrial waste or organic waste.

| Mt Eden Enabling Works

Contamination Delivery Work Plan Contaminated fill Contaminated fill comprises: • • •

Soil with concentrations of contaminants exceeding managed fill acceptance criteria. Household and industrial waste. Asbestos in soil and/or ACM.

5.4 Spoil disposal Surplus spoil requiring offsite disposal shall be managed according to the location and nature of the material, as follows: Surficial fill materials • • • • •

Fill is present across the site varying in depth but typical present between 0.4 m and approximately 4.0 m bgl; Based on the available results, fill materials will require disposal as either managed or licenced landfill; Disposal to managed fill is subject to compliance with the spoil meeting the acceptance criterial of the disposal location; Any contaminated fill (as defined in the previous section) will be disposed of to a licenced landfill; and Trucks taking spoil for disposal offsite must be lined/ wrapped if required by the receiving managed fill facility and in accordance with Table 5-1.

Natural materials • •

Following removal of all fill material, the underlying natural material, if free from staining or odour, is suitable for disposal as cleanfill; and The receiving facility may require confirmatory testing, which should be undertaken in accordance with the soil sampling procedures detailed in Section 5.10.

In all cases: • • •

Truck transporting spoil for disposal offsite will be covered; The necessary permits from the disposal site operator will be obtained to confirm that the facility can receive the materials prior to off-site transportation; and All weighbridge dockets and/or a summary sheet will be retained for inclusion in validation reporting at completion of the works (refer to Section 8).

There is limited opportunity for reuse of spoil. If spoil is to be re-used the appropriate environmental controls (if any) are to be advised by the CLS. Such controls may include encapsulating the soil (refer finishing surface/cap requirements in Table 5-1).

5.5 Transportation of spoil The following measures shall be implemented to prevent spoil from being dispersed onto roads or transported to another site (excluding transport to a disposal facility) as well as to minimise generation of dust: •

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Any excess soil on vehicle tyres shall be removed before vehicles leave the works area. A wheel wash will be established on site and vehicles that have tracked over exposed soils will be required to exit the works area via the wheel wash; | Mt Eden Enabling Works

Contamination Delivery Work Plan • • •

Excess soil shall be removed from vehicles and plant before they leave the works area; All trucks transporting excavated spoil to the selected disposal facility shall be covered to prevent the spillage of spoil and dust emissions; and Additional controls (refer vehicle protection and vehicle washing facilities in Table 5-1) are required for the disturbance of asbestos contaminated fill material on the South Pacific Timber site, unless further testing is undertaken to justify that the controls are not required. Such controls include: o Visual assessment by a competent person following cleaning of vehicle before leaving the works area. o Depending on the requirements of the receiving site truck lining/soil wrapping of fill material during transport may be required.

If a higher concentration of asbestos fibres is detected as part of any additional testing or discovery of unexpected contamination, then the relevant level of controls outlined in Table 5-1 shall be implemented.

5.6 Water management Separation and diversion of clean stormwater away from areas of ground disturbance is standard practice for any earthworks activity but becomes more important where contaminants are present. To minimise the potential for clean stormwater to encounter contaminated soil the stormwater and sediment controls detailed in the ESCP for the Mt Eden Enabling Works shall be implemented. Site water including surface water that has been in contact with disturbed ground, groundwater and perched water requiring removal is to be managed via the following methods: • •

•

Piped or pumped to a sediment control system or settlement tank(s); Further treatment (i.e. flocculent additives, pH adjustment) in accordance with the procedures detailed in the Flocculation Treatment Management Plan (FTMP) for the works; and Testing in accordance with the Water Quality Discharge Monitoring Programme (WQDMP) included in the Flocculation Treatment Management Plan (FTMP) to confirm compliance with the criteria for discharge to stormwater.

Alternatively, site water will either be disposed by licensed liquid waste contractor to a licenced facility or discharged to sewer (subject to approval by Watercare Services Limited). For discharges to sewer monitoring shall be conducted in accordance with the applicable permit conditions, e.g. trade waste agreement requirements.

5.7 Dust management To minimise the generation of dust during earthworks (particularly during earthworks within fill), the following controls shall be implemented: •

• • • Page 23

Weather forecasts shall be obtained each day during work to check for predicted high wind conditions and any such predictions shall be notified to relevant construction staff so that dust management procedures are adequately prepared and implemented; In windy conditions, if soils are dry and friable during excavation then they shall be dampened with water; Limit drop heights of soil from the excavator bucket into trucks; Immediately clean up spilled soil from truck loading areas prior to loading additional trucks; | Mt Eden Enabling Works

Contamination Delivery Work Plan • • •

Ensure vehicles do not leave site with excess soils between the tyre tread as this will be distributed on public roads and will generate dust; If dust cannot be controlled during excessively windy conditions, then earthworks shall cease until dust can be managed; and If a dust release occurs, the time, duration, location and cause is to be recorded in the daily report as well as remedial action performed.

Further dust management and monitoring requirements are set out in the AQ DWP prepared for the Mt Eden Enabling Works.

5.8 Odour management The contaminants in soil and groundwater, particularly during excavation in the fill, are unlikely to generate odours and vapours. If odorous soil is encountered, then the actions outlined below shall be implemented: • • •

• •

Limit the time that the excavation of odorous materials is exposed and occur; Removing excavated odorous material from site as quickly as possible in covered trucks; The odorous material shall be covered to suppress odour emissions, and work in that area suspended until suitable mitigation measures can be put in place if the odorous material cannot be removed quickly; Install an odour suppressant system if appropriate; and Install a ducted fan or additional mechanical ventilation to reduce vapour concentrations in the area if required.

If odorous material is encounter, the time, duration, location and cause is to be recorded in the daily report as well as remedial action performed, including notifying the CLS. Further dust management and monitoring requirements are set out in the AQ DWP prepared for the Mt Eden Enabling Works.

5.9 Sampling and testing Any sampling and testing of soils shall be undertaken by the CLS according to the requirements of the NES Soil Regulations and the MfE Contaminated Land Management Guidelines No.5. Site Investigation and Sampling (revised 2011). Samples for asbestos testing shall be collected in accordance with the NZ Asbestos in Soil Guidelines. Soil samples shall be collected according to the following procedure: •

• • •

The materials encountered shall be described in accordance with the NZ Geotechnical Society Guidelines for the classification and field description of soils and rocks for engineering purposes; Hands shall be freshly gloved to collect soil and the samples shall be placed immediately into the appropriate laboratory supplied sample containers; Any equipment used to collect the samples shall be decontaminated between sample locations using clean water and Decon 90 (a phosphate-free detergent) rinses; and Samples shall be shipped in chilled container to an IANZ certified laboratory under chain of custody documentation.

As a minimum, testing shall be for metals and PAH. Any evidence of the presence of asbestos shall trigger testing for asbestos content in soil. Page 24

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Contamination Delivery Work Plan The CLS shall evaluate any analytical results against the relevant human health and environmental discharge regulatory standards/acceptance criteria as appropriate.

5.10 Imported material requirements It is not anticipated that soil materials will be imported as part of the Mt Eden Enabling Works. In the event that soil materials are imported these shall originate from: •

•

A site which has been determined by a suitably qualified contaminated land professional to have had no known history of potentially contaminating activities, as detailed on MfE’s Hazardous Activities and Industries List (HAIL); or A site which has been adequately investigated by a suitably qualified contaminated land professional, in accordance with MfE’s Contaminated Land Management Guidelines No. 5 Site Investigation and Analysis of Soils (revised 2011), to meet the ‘cleanfill material’ definition as prescribed in the AUP (refer Section 5.3).

Soil materials imported will typically be tested at a rate of 1 in 500 m3 for metals and PAH and any evidence of the presence of asbestos shall trigger testing for asbestos content in soil. The CLS will determine the required rate and analytes based on the source site. It is preferable that the fill is tested at its source prior to its use at the site. However, if not, then the imported soil materials shall be stockpiled on site with appropriate controls until test results are available. Additional, engineering materials may be used including clean quarry materials and recycled crushed concrete aggregate that is site won or sourced from a quarry or supplier. The supplier of these materials are to provide documentation to confirm suitability for use. For crushed concrete aggregate the additional information is required: •

•

Sourced from the site: address of the source site, copies of pre-demolition asbestos surveys, copies of asbestos clearance certificates prepared prior to demolition and asbestos testing at a rate of 1 in 500 m3. Sourced from a supplier: confirmation of processing procedures and asbestos testing at a rate of 1 in 500 m3 of product is to be provided by the supplier. The CLS shall review the supplied information prior to acceptance or the material stockpiled on site until available.

5.11 Sealing excavation service trenches If contaminated material is encountered and sealing of excavation service trenches is required to prevent them from acting as a conduit for migration of contaminated groundwater away from the site, a pipe dam shall be installed at the site boundary. The pipe dam shall be either concrete or another impervious material to be specified by the drainage design engineer. The dam shall encase the pipe and extend up the trench to just below the paved surface as shown in Figure 5-1 below. The locations of pipe dams will be recorded on as-built drainage drawings and included in the validation reporting at completion of the works (refer to Section 8).

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Contamination Delivery Work Plan

Figure 5-1: CRL Route and Location

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Contamination Delivery Work Plan

Health and safety contamination procedures 6.1 Overview

This C DWP provides procedures for site personnel working in and around contaminated and/or potentially contaminated soil and water during the excavation works. The following is designed to dovetail with the Construction Health and Safety Management Plan. The procedures have been developed to provide a framework for managing contamination related effects at the site. However, these procedures are not intended to relieve the owner or controller of the place of work of either their responsibility for the health and safety of their workers, contractors and the public, or their responsibility for the protection of the environment. All parties working on the Project shall comply with: • • • • •

Applicable parts of the Health and Safety Policy; Construction Health and Safety Management Plan; Any requirements of WorkSafe New Zealand; The Health and Safety at Work Act 2016 and Regulations; and Any other applicable legislation, regulations, codes and guidelines.

Sub-contractors engaged on the project are required to provide their own Health and Safety Plan for their equipment and workers. Daily toolbox meetings are to be undertaken and documented by the Health and Safety Officer (HSO) or delegate.

6.2 General safety requirements and training All personnel shall be required to participate in a site induction that includes a review of procedures with respect to contamination. The induction shall be provided such that all relevant personnel understand, prior to commencing work, what procedures are to be implemented and why. The purpose of the induction is to educate the workers with respect to the hazards associated with contaminated soil and water, safe working procedures, safety equipment and requirements, and the response plan in the event of an emergency. An appropriately qualified HSO, or similar, shall be appointed for the duration of the works so that where contamination is being managed, there is a designated person responsible for the implementation of and adherence to contamination related health and safety procedures, in addition to the other site specific health and safety requirements. The HSO shall ensure that all relevant personnel are familiar with the application and use of required PPE and procedures specified in this C DWP and other site specific documentation prior to the commencement of work. The following general safety procedures shall be followed by all personnel entering and/or working in the construction zone: • • Page 27

Hazards encountered and not identified during the site induction/toolbox shall be reported to the designated HSO; Any incidents shall be reported to the HSO; | Mt Eden Enabling Works

Contamination Delivery Work Plan • •

Site personnel shall avoid unnecessary contact with documented and potentially contaminated soil and groundwater; and Site personnel who may come into contact with contaminated soil shall be provided with the minimum level of PPE as defined in Section 6.7 of this C DWP.

6.3 Control measures When considering hazard and risk controls, the hierarchy listed below should be followed, in preference from one to five. Example questions are provided to illustrate each step. • • • •

•

ELIMINATION – does the task that creates the hazard need to be performed? SUBSTITUTION – can a different tool be used? ENGINEERING – can the hazard be guarded to protect people? ADMINISTRATION – are there warning signs and a procedure to address the hazard? Administrative controls include procedures to reduce the risks associated with identified hazards. These controls include: o Job Safety Analysis (JSA) or Task Analysis. o Work plans. o Training. o Warning signs. o Communication with the Site Manager/HSO. PERSONAL PROTECTIVE EQUIPMENT – is the appropriate PPE being used? The following is noted. o PPE is considered the lowest level of protection against a hazard. o No single combination of protective equipment and clothing can provide protection against all hazards; PPE should be used in conjunction with other protective methods. o The types of PPE will depend on the specific task undertaken. However, certain PPE is required in all work areas.

6.4 Identification of hazards Contamination investigations indicate low level contamination within fill material and groundwater (refer Sections 3.3 and 3.4). The fill material contamination includes metals/metalloids, hydrocarbons and asbestos, and groundwater was found to exceed consented discharge criteria for some metals/metalloids. Potential exposure routes for contaminants include: • • • •

Inhalation of dust (potentially contaminated and uncontaminated); Ingestion of potentially contaminated soil, dust or groundwater; Dermal absorption of potentially contaminated soil or dust; and Skin and eye contact with potentially contaminated soil or dust.

Recommended procedures to mitigate the risk associated with these hazards are provided in Section 6.6. Other hazards that may be identified if unexpected contamination is encountered (refer Section 7).

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6.5 Identification of new hazards There is the potential for additional hazards to be identified and encountered during the Mt Eden Enabling Works. The HSO is responsible for reviewing any new work element and assessing whether there are any new associated hazards and associated elimination, isolation and minimisation measures. The HSO shall seek review by the CLS if necessary. The HSO shall then instruct all personnel on the health and safety procedures associated with the new hazard.

6.6 Hazard mitigation procedures 6.6.1. Dust inhalation Inhalation of dust (whether it is contaminated or not) can pose a health risk and therefore the dust control measures shall be implemented for the duration of the earthworks as detail in the AQ DMP and outlined in Section 5.7 of this C DWP. The following additional measures shall be considered to minimise inhalation of dust: • • •

Monitor wind speed and direction, and where practicable, stand up wind of excavations and vehicle loading areas; Water spray via localised points; and Boot wash available for personnel leaving excavation areas to prevent the tracking of soil around and off-site.

Additional controls are required if a higher concentration of asbestos fibres is detected as part of any additional testing or if unexpected contamination is encountered. The controls to be implemented are outlined in Table 5-1 and include the use of a polymer spray in addition to water to manage dust and additional PPE (i.e. disposable coveralls, and respiratory protective equipment).

6.6.2. Vapour and gas inhalation The investigations to date indicate there is a low potential for the presence of volatile contaminants or gases that are likely to represent a human health risk with respect to the inhalation exposure route. However, mitigation of vapour or risk can be achieved as follows: •

•

If there are olfactory indications for vapours or vapours are suspected, the volatile organic compound (VOC) content of the area shall be checked with a calibrated photo-ionisation detector (PID) with a 10.6 electron volt (eV) lamp. If readings are above 50 ppm, work shall stop, the area vacated and the CLS and/or HSO shall be informed. A respirator shall be worn when re-entering the area to re-test the atmosphere; At the same time, and if an area or excavation is to be accessed with limited air flow (i.e. excavations below existing floor slabs) air quality shall be monitored prior to entry using a calibrated gas meter(s) able to measure lower explosive limit (LEL), oxygen (O2), methane (CH4), carbon monoxide (CO) and hydrogen sulphide (H2S); and Work shall not resume unless approved by the HSO in consultation with the CLS.

6.6.3. Dermal contact and ingestion The following precautionary measures shall be implemented to ensure skin contact with and ingestion of contaminants is minimised:

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Contamination Delivery Work Plan •

• • •

Disposable gloves shall be worn by personnel who need to have contact with contaminated soil during the excavation works. Consideration shall be given to the requirement for tear resistant gloves; Overalls shall be worn if there is the potential for contaminated soil to contact other parts of the body (legs, arms etc.); Boot covers shall be worn by personnel who need to traverse contaminated soils during excavation works or washable boots worn with a boot wash in place and utilised; and There shall be no eating, drinking or smoking in the works area to prevent contaminated soil contacting food or being ingested directly via soiled hands.

A key factor in controlling dermal contact and ingestion of contaminated soil is through maintaining good personal hygiene. The following shall be observed for works involving contaminated soils: • • • • •

Hand to mouth and hand to face contact shall be avoided during work; Hands shall be washed before eating, drinking and smoking; Eating, drinking and smoking shall only be permitted in designated areas; Overalls worn within the works area shall be removed before leaving the works area; and Disposable coveralls may be worn and disposed of at the end of each working day.

6.7 Personal protective equipment All workers handling or coming into contact with contaminated or potentially contaminated soil shall wear the following PPE to protect against the above risks: • •

Overalls or disposable coveralls; and Impermeable gloves (tear resistant if appropriate).

Additional PPE (refer PPE and minimum respiratory protective equipment in Table 5-1) are required if a higher concentration of asbestos fibres is detected as part of any additional testing or if unexpected contamination is encountered. Such controls include the use of disposal coveralls (rated type 5, category 3), disposal overshoes (or similar) and specific respiratory protective equipment depending on the type and concentration of asbestos present (as a minimum disposable P2 dust mask shall be available on site). Changes to site specific PPE requirements shall be reflected in all health and safety documentation and all parties notified. The PPE specified above is in addition to that required for non-contamination related health and safety.

6.8 Communication plan Details of communication and consultation procedures are set out within the Mt Eden Enabling Works Communication and Consultation Plan (CCP). The CCP outlines the way in which the general public are to be communicated with on CRL project matters, including the management of adverse effects relating to the contamination and the process for public and affected parties to register a complaint.

6.9 Incident reporting Procedures relating to environmental emergencies and incidents are detailed within the CEMP. The CEMP should be referenced for further information on environmental incidents including spill response, incident recording and reporting.

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Contamination Delivery Work Plan

Contingency measures 7.1 Unexpected discovery of contamination

If during earthworks, contaminated soils or hazardous material in addition to those described in Section 3.3 is encountered, work in the area of concern shall cease until the CLS has assessed and identified the material. Evidence of additional contamination likely to trigger a stop work procedure may include: • • • • •

Visual (buried refuse, metal objects, building material, soil or water staining/bleaching or discolouration); Chemical odours (fuel, sulphurous, rotting vegetation or sewage); Separate phase liquids or ‘rainbow effect’ films on groundwater; Auditory (gas leaks, flowing or dripping liquid); and Fibrous cement based board materials that may contain asbestos.

If any such indicator is observed during earthworks, the following steps should be taken: • • • • •

• •

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Cease all work within a 10 m radius and make the work area safe and restrict access to all workers until instructed by the ESM or delegate; Shut off all ignition sources and, if possible, contain any contaminant discharge and close/divert any water flow; Advise the ESM; Work shall not resume until the ‘all clear’ is given by the ESM; The ESM (in consultation with the CLS) shall assess the site. If the assessment concludes that confirmation of contamination is required, the following actions shall be implemented: o Control the site: install temporary fencing, temporary cover, silt traps and bunding as required around the area of potential contamination o Small volumes of excavated soil shall be contained in covered skips to minimise contaminated discharges from rainfall runoff and dust o If this is not possible, larger volumes shall be covered and bunded to manage dust and stormwater runoff o Potentially contaminated water shall be collected and disposed of to an appropriately licensed treatment facility. It must not be discharged to the construction stormwater system o Samples of the suspect material shall be collected (by the CLS or delegate) for laboratory analyses using appropriate procedures (refer Section 5.10) The results of the laboratory analysis shall be assessed against the relevant human health and environmental discharge regulatory standards/acceptance criteria as appropriate; The CLS should be consulted on the handling and management of contaminated soil and/or water, and any specific health and safety precautions that may need to be taken to minimise risk to construction workers/and or the general public; Any soils or material requiring off-site disposal must be disposed of at facilities consented to accept the material; and Maintain a register of any additional contaminated material discovered, including location, type, quantity and disposal record (disposal receipts). This information will be documented in the Site Validation Report (refer Section 8). | Mt Eden Enabling Works

Contamination Delivery Work Plan •

Where unexpected contamination is significantly different in extent and concentration from that anticipated, the Council (Team Leader Central Monitoring) will be advised prior to carrying out any further work in the area of the unexpected contamination.

7.2 Water discharges As described in Section 5.6, where the quality of water being discharged from the site cannot meet the standards required for discharge to stormwater, or unexpected contamination conditions are encountered (refer to Section 7.1), additional controls will be required. If unexpected contamination conditions are encountered the area in which unexpected contamination conditions have been encountered shall be isolated so that site water from this area can be separated from that generated across the wider site. A number of options could be employed if the quality of water being discharged from the site cannot meet the standards required for discharge to stormwater on an ongoing basis, including, but not limited to: • • •

Improving effluent quality through additional treatment; and/or Collection (for example by tanker trucks) for off-site disposal to an appropriately licensed facility; and/or Discharge to sewer, subject to removal of sediment and issue of any necessary temporary trade waste permits.

The CLS shall be consulted to assist with defining appropriate control measures in the event that the standards required for discharge to stormwater cannot be met.

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| Mt Eden Enabling Works

Contamination Delivery Work Plan

Works summary/validation reporting

On completion of the soil disturbance works associated with the Mt Eden Enabling Works, a works completion report (also referred to as a site validation report) will be prepared and provided to Auckland Council. The purpose of the works summary report is to confirm that the objectives of the works have been achieved, and that the works were undertaken according to agreed procedures and reporting on any incidents. The report is required to be prepared by the CLS and shall comply with the MfE Contaminated Land Guideline No. 1 - Guidelines for Reporting on Contaminated Sites in New Zealand (revise 2011). The report shall include, as a minimum: • • • • • • • • •

A summary of the works undertaken, including a site plan and a statement confirming whether the excavation of the site has been completed in accordance with the certified C DWP; The location and dimensions of the excavations carried out, including relevant site plan and location of contaminated soil reused (if any); Summary of the disposal dockets for the spoil disposed off-site; Summary of the inspections undertaken by the CLS during disturbance of contaminated soil; Records of any unexpected contamination encountered during the works and contingency measures undertaken (if applicable); Details regarding any complaints and/or breaches of the procedures related to contamination; Results of any testing undertaken; Documentation and results of testing of any imported fill; and Any long-term monitoring/management requirements.

This report shall be provided to Auckland Council within three months of completion of the soil disturbance works associated with the Mt Eden Enabling Works.

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| Mt Eden Enabling Works

Contamination Delivery Work Plan

Appendix A: ISCA Requirements Table A identifies the ISCA Credit Requirements relevant to this Contamination DWP and where they are addressed in the documents. Requirements *

Relevant Section

Other Relevant Information / Comments

Lan-3 Level 1

Site assessment follows the recommended approach in ‘CLMG No.5 Site Investigation and Analysis of Soils’.

Section 3

A site assessment has been completed in the vicinity of the Mt Eden Enabling Works area as part of the wider CRL project. Specific assessments have not been undertaken within the Mt Eden Enabling Works area, with the exception of the South Pacific Timber site (21 Ruru Street).

Lan-3 Level 1

Remediation options are identified and selected using a sustainability hierarchy.

Sections 5.3, 5.4, 5.6 and 7.

Lan-3 Level 2

Sustainability appraisal of remediation options is undertaken against the sustainability indicators in Table 1 of ‘A Framework for Assessing the Sustainability of Soil and Groundwater Remediation’.

Shallow contaminated fill (and underlying natural material) needs to be removed as part of the Mt Eden Enabling Works. The spoil within the Mt Eden Enabling Works area needs to be removed and disposed of offsite to enable this component of the CRL project to be realised. Due to the urban and constrained nature of the works area there is no location within the CRL project area for soils to be retained or returned to site. Disposal of soil from the Mt Eden Enabling Works shall be based on the soil classification hierarchy and approval process that is outlined in Sections 5.3 and 5.4 of this C DWP. If unexpected soil contamination is identified, the requirements of Section 7 of this C DWP are to be implemented and soil remediation and management options will be assessed using the ISCA sustainability hierarchy approach as applicable.

Section 5.6

A Water Discharge Quality Monitoring Programme (WDQMP) has been developed which specifies the monitoring to be undertaken for the Mt Eden Enabling Works. The WDQMP is included within the FTMP and provides specific requirements on the discharges to the receiving environment (Motions Creek

Credit Whenua (Land)

Receiving Wai (Water) Quality DIS-1 Level 1

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Measures to minimise adverse impacts to receiving wai environmental values during construction and operation have been identified and implemented. These measures demonstrate an awareness of the values of wai ora and its Mauri, and

| Mt Eden Enabling Works

Contamination Delivery Work Plan Credit

Requirements *

Relevant Section

Other Relevant Information / Comments

Whenua (Land) opportunity for mana whenua feedback has been provided and where practicable incorporated into these measures. AND Monitoring of wai discharges and receiving wai is undertaken at appropriate intervals and at times of discharge during construction.

and ultimately the upper Waitemata Harbour).

ISCA Lan-3 sustainability hierarchy The ISCA Lan-3 sustainability appraisal process includes the following sustainability hierarchy for remediation: • • • • •

If practicable, on site treatment of the contamination so that it is destroyed or the associated risk is reduced to an acceptable level. Off-site treatment of excavated soil, so that the contamination is destroyed or the associated risk is reduced to an acceptable level, after which soil is returned to the site. Consolidation and isolation of the soil on site by containment with a properly designed barrier. Removal of contaminated material to an approved site or facility, followed, where necessary, by replacement with appropriate material. Where the assessment indicates remediation would have no net environmental benefit or would have a net adverse environmental effect, implementation of an appropriate management strategy.

If an option less favourable than the first option is selected, then justification for not selecting options higher on the hierarchy must be provided. In cases were no readily available or economically feasible method is available for remediation, it may be possible to adopt appropriate regulatory controls to develop other forms of remediation.

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| Mt Eden Enabling Works

Contamination Delivery Work Plan

Appendix B: Staging Drawings Refer to Appendix B of the CEMP.

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Contamination Delivery Work Plan

Appendix C: Record of CLG, IPR and Auckland Council Comments C-1: Community Liaison Group (CLG) Comments A Mt Eden CLG meeting was held on 8th October to discuss the Mt Eden Enabling Works and for the CLG to provide comments / feedback on the CEMP and sub-plans, including this C DWP. No comments were received from the CLG on this C DWP.

C-2: Independent Peer Review (IPR) Comments The Contamination DWP was reviewed by the Independent Peer Reviewer â€“ Terre Nicholson of HD Geo Limited. Comments received from the Independent Peer Reviewer are documented along with details of resolution are in the following table. Section of this Contamination DWP

Comment

Response

5.10, 5.11, 6.4, 6.6.3

Minor edits for clarity.

Edits made as noted.

C-3: Auckland Council Comments The Contamination DWP was reviewed by Auckland Council Senior Contamination Specialist â€“ Marija Jukic. Comments received from Auckland Council are documented along with details of resolution are in the following table. Section of this Contamination DWP

Comment

Response

5.3: Managed Fill

Definition of Managed Fill under the Auckland Unitary Plan (Operative in Part) explicitly excludes the acceptance of any asbestos to such facilities within the Auckland region. Proposed sampling rate and analytes to be tested have not been included.

Added note that there are currently no managed fill tip sites in the Auckland Region that can accept asbestos.

5.10: Imported

fill

7.10:

Unexpected Discovery of Contamination

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No reference is made to the Team Leader of Central Monitoring being notified upon the unexpected discovery of contamination.

| Mt Eden Enabling Works

Added typically sampling rate and analytes. To be confirmed by the CLS based on the source site. With further update to reduce the typically sampling rate from 1 in 1,000 m3 to 1 in 500 m3. Added requirement to advise prior to carrying out any further work in the area of unexpected contamination.