Contamination delivery work plan

Auckland City Rail Link

Version history

This document remains the property of DSBJV. Its contents are confidential and shall not be reproduced, destroyed or given away without express, written permission of DSBJV. The electronic version of this document in FULCRUM on designated serves(s) is the Master Copy and is a controlled document. Unless specifically noted, thereon, other copies of this document are uncontrolled.

j:\crl c1\08 environment sustainability\0801 environmental management plans and delivery work plans\x annual management plan reviews\2018\tracked change - draft versions\crl-btm-env-dow-pln-000295 contamination dwp rev 10.docx

Appendix

Appendix

Appendix

Glossary of terms

Acronym Definition

ACZ Active construction zones

ALW Plan

Auckland Council Regional Plan: Air, Land and Water

bgl Below ground level

BTC Britomart Transport Centre

CEMP Construction Environmental Management Plan

CLG Community Liaison Group

CLP Contaminated Land professional

CPO

Former Chief Post Office building

CRL City Rail Link

CRLL City Rail Link Limited

CSMP Contaminated Soils Management Plan

DWP Delivery Work Plan

HSO Health and safety Officer

IS Infrastructure Sustainability

ISCA Infrastructure Sustainability Council of Australia

m Metre

MfE Ministry for the Environment

mg/L Milligrams per litre

NES Soil Regulation 11 of the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011

PAH

Polycyclic aromatic hydrocarbons

PAUP Proposed Auckland Unitary Plan

PID Photo-ionisation detector

PPE Personal protective equipment

SQEP Suitably qualified and experienced practitioner

VOC Volatile organic compound

1 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 in the vicinity of Mt Eden station. The works relating to this Contamination Delivery Work Plan (DWP) constitute part of the enabling works for the CRL.

The works (the Project) involve the construction of an extension to the existing passenger rail network from the current termination point within the Britomart Transport Centre (BTC), westwards underneath the former Chief Post Office building (CPO) and Lower Queen Street. The Project footprint is shown by the blue shaded area in Figure 1.1 below.

1.1

Purpose of the Contamination DWP

CRL alignment

BTC designation

CRL designation

C1 worksite

This Contamination DWP has been prepared to manage the adverse effects relating to contaminated land during the construction of the Project Specifically, the purpose of the plan is:

• To avoid, remedy or mitigate the adverse effects of the construction on human health, which may result from the disturbance of contaminated fill (as defined in Section 4.4.1 of this DWP) during construction; and

• To minimise discharges to land or water from contaminated fill within the Project footprint

The CRL designation (conditions 57 and 58) requires the preparation of a DWP while conditions 77 to 94 of the discharge permit (R/REG/2014/5435) require a Contaminated Soils Management Plan (CSMP). These two separate document requirements have been combined and are addressed in this single Contamination DWP.

The Contamination DWP addresses the following:

• A summary of soil and groundwater quality within the Project footprint based on previous Project contamination assessments and additional soil sampling during enabling works;

• Management of contaminated fill and groundwater within the Project footprint, including soil classification, sampling and testing;

• Procedures to manage the disturbance of contaminated fill during earthworks activities, including measures for reducing human exposure to contaminated fill and minimising contaminated discharges to air, land or water;

• Contamination Health and Safety Plan; and

• Contingency measures to manage any unexpected discovery of contamination.

This Contamination DWP is an updated version of the DWP issued in June 2016 and updated in 2017, both prepared by Tonkin & Taylor Ltd (T+T) for the Downer Soletanche Bachy Joint Venture (the Contractor - DSBJV). The DWP has been prepared in general accordance with Ministry for the Environment (MfE 2011) Contaminated Land Management Guideline No. 1: Reporting on Contaminated Sites in New Zealand, and forms part of the Construction Environmental Management Plan (CEMP) for the Project. This updated version has been prepared in compliance with CRL designation Condition 23 (refer Section 9 for more detail).

1.2 Relevant Conditions

Table 1.1 identifies the CRL designation and discharge permit conditions relevant to this Contamination DWP and where they are addressed in the document.

Table 1.1: Contamination DWP Conditions and section where addressed in the DWP

Condition No. Condition Relevant section of the DWP

CRL Designation Conditions

Contamination DWP

57.1A 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.

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 document

This document

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

a) Health and safety plan that addresses: - worker safety - worker training with regard to handling and identifying potentially contaminated soil and notification procedures for discovery of contamination

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

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

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

e) 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

Section 6.2

Section 5

Sections 4 and 5

Section 4.7

Section 7.1

Condition No. Condition Relevant section of the DWP

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

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

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

i) 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.

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.

Discharge Permit (R/REG/2014/5435)

78 At least 20 working days prior to the commencement of construction, a final CSMP shall be submitted to the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input and Team Leader Central Monitoring) for certification. The CSMP shall be prepared by a suitably qualified and experienced Contaminated Land Professional in accordance with Schedule 13 (A4) of the Auckland Council Regional Plan: Air, Land and Water (ACRP:ALW). The Consent Holder shall request the Council’s (Team Leader Central Monitoring) determination as to whether the CSMP can be certified, in writing, within 10 working days of receipt of the CSMP.

79 No construction shall commence until certification is provided from the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input and Team Leader Central Monitoring) that the CSMP meets the requirements of Schedule 13 (A4) of the ACRP:ALW.

80 All measures identified in that CSMP must be established prior to the commencement of bulk earthworks.

81 The CSMP shall address the following matters:

a) Identification of mitigation measures to ensure that discharges from the construction support areas to land or water are minimised, and to ensure that potential effects on the health of workers on the site and nearby sites can be appropriately managed

b) 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 5

Sections 4.4.2, 7.1and 8

Section 5.2

Sections 4.1 and 7.2

Section 8

This document, Section 1.4

This document

Section 5.1

Sections 4 and 5

Section 2 and Appendix B

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

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

e) Contingency measures for unexpected discovery of contamination;

f) Proposed gas monitoring in the Lower Queen Street area, and any other proposed sampling and analysis, if applicable; and

g) Proposed Works Summary Reporting.

Advice Note: The Council acknowledges that the CSMP is intended to provide flexibility of 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 be consistent with the conditions of this consent. If you would like to confirm that any proposed updates are within scope, please contact the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input) on (09) 301 0101.

82 All disturbance of contaminated and potentially contaminated soil as part of the bulk earthworks activity shall be carried out in accordance with the certified CSMP required by Condition 78 and any changes to the plan shall be submitted to the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input and Team Leader Central Monitoring) for certification prior to the change being implemented. No activity reliant upon a change to the CSMP can be undertaken until the change has been certified. The Consent Holder shall request the Council’s (Team Leader Central Monitoring) determination as to whether the proposed change can be certified, in writing, within 10 working days of submission of the change.

83 The Consent Holder shall notify the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input and Team Leader Central Monitoring) at least two working days prior to the commencement of bulk earthworks on the subject site

Advice Note: Condition 83 requires the consent holder to notify the Council of their intention to begin works in contaminated areas a minimum of two working days prior to commencement of construction. Please contact the Team Leader, Earthworks and Contaminated Land, Natural Resources and Specialist Input at david.hampson@aucklandcouncil.govt.nz to advise of the start of works. The following details should also be provided:

- 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.

84 All disturbance of contaminated soil shall be supervised by a suitably qualified and experienced Contaminated Land Professional who shall ensure that soil management and disposal procedures, contingency

Section 5

Section 5.3

Section 7.1

Sections 6.6.2 and 4.5

Section 8

Section 1.3

Section 1.1 and 1.4

Section 4.1

Sections 4.1, 5.7 and 8

Condition No. Condition

measures outlined in the certified CSMP required by Condition 78, and all relevant consent conditions are adhered to. Regular inspections of the works area shall be carried out by the Contaminated Land Professional. These inspections shall be documented and the relevant records shall be retained and provided to Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input) as part of the Works Summary Report required by Condition 93.

85 All land disturbance works shall be managed 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. Soils that are identified for offsite disposal must be loaded directly for removal where possible, and all material shall be covered during transportation off-site.

86 To minimise the spread of contaminated material, any temporary stockpiles of 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.

87 Excess soil or waste materials removed from the Project worksite shall be deposited at a disposal site that holds a resource consent to accept the relevant level and type of contamination

88 Where it can be demonstrated that the soil has been fully characterised and meets the definition of ‘cleanfill’ in accordance with the Ministry for the Environment’s publication ‘A Guide to the Management of Cleanfills’ (2002), 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 ‘cleanfill’ shall be kept for the purpose of being included in the Works Summary Report required by Condition 93.

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

a) be disposed of by a licensed liquid waste contractor; or

b) pumped to sewer, providing relevant permits are obtained; or c) 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.

90 Where contaminants are identified that have not been anticipated by the application, works in the area containing the unexpected contamination shall cease until the contingency measures outlined in the certified CSMP required by Condition 78 have been implemented, and have been notified to the Council (Team Leader, Earthworks and Contaminated Land, Natural Resources and Specialist Input). Any unexpected contamination encountered during the works and contingency measures implemented shall be documented in the Works Summary Report required by Condition 93.

Advice Note: In accordance with Condition 90 any unexpected contamination may include separate phase hydrocarbons, contaminated soil, perched water or groundwater. The consent holder is advised that

Section 5.2

Section 5.2

Section 4.4

Sections 4.4 and 8

Section 5.3

Section 7

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 Earthworks and Contaminated Land, Natural Resources and Specialist Input) prior to carrying out any further work in the area of the unexpected contamination to ensure this is within the scope of this consent.

91 All imported fill shall:

a) comply with the definition of 'cleanfill' in the Ministry for the Environment publication 'A Guide to the Management of Cleanfills’ (2002);

b) be solid material of an inert nature; and

c) not contain hazardous substances or contaminants above recorded natural background levels of the receiving site.

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

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

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 Part 4: Laboratory Analysis, of Contaminated Land Management Guidelines No.5

93 Within three months of the completion of bulk earthworks on the site, a Works Summary Report shall be provided to the Council (Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input and Team Leader Central Monitoring). The Works Summary Report shall be prepared by a suitably qualified and experienced Contaminated Land Professional in accordance with Schedule 13 (A5) of the Auckland Council Regional Plan: Air, Land and Water and Contaminated Land Management Guidelines, No.1 - Reporting on Contaminated Sites in New Zealand, Ministry for the Environment (revised 2011).

Section 4.6

Section 4.5

Section 8

94 The Works Summary Report shall address the following matters: Section 8

a) 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 78;

b) the location and dimensions of the excavations carried out, including a site plan;

c) a summary of soil, perched water and groundwater testing undertaken (if applicable) including tabulated analytical results, and interpretation of the results in the context of the Contaminated Land Rules of the Auckland Council Regional Plan: Air, Land and Water and the Proposed Auckland Unitary Plan;

d) copies of the disposal dockets for the contaminated soil and ‘cleanfill’ material removed from the site;

Condition No. Condition Relevant section of the DWP

e) records of any unexpected contamination encountered during the works and contingency measures undertaken (if applicable);

f) details regarding any complaints and/or breaches of the procedures set out in the certified CSMP required by Condition 78 and the conditions of this consent;

g) results of testing, if required, of any spoil disposed offsite; and

h) results of testing of any imported fill material to ensure compliance with the definition of 'cleanfill', as per 'A Guide to the Management of Cleanfills’, Ministry for the Environment (2002).

1.3 Sustainability

City Rail Link Limited (CRLL) is seeking an Infrastructure Sustainability Council of Australia (ISCA) Infrastructure Sustainability (IS) Rating. Further details can be found in the Project CEMP and Sustainability Rating Management Plan. Project sustainability requirements that relate directly to this Contamination DWP are included in Appendix A. These requirements are imbedded within tis Contamination DWP 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.

1.4 DWP Review and updates

This DWP is a live document that will be reviewed and updated if needed during the course of the Project to reflect changes in the understanding of ground contamination in the Project area, accepted best operational practice or regulations. Any material changes to this DWP must be certified by Auckland Council prior to any on-site activity reliant upon the change commencing. A formal review process is described in Section 9 of this DWP.

1.5 Contamination DWP Author

This Contamination DWP has been prepared by Lean Phuah who is a Contaminated Land Professional at T+T. Lean has Bachelor of Civil Engineering degree from the University of Canterbury and is a chartered professional engineer working in the environmental practice area. She has more than 20 years’ experience in investigations, assessment, management and reporting of contaminated sites. She is a suitably qualified and experienced practitioner under the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (NES Soil).

The annual review of the Contamination DWP has been undertaken by Elyse LaFace and reviewed by Lean Phuah. Elyse is an Environmental Scientist at T+T. Elyse has a 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.

2 Project Description

2.1

Overview

The Project involves the construction of an extension to the existing passenger rail network from the current termination point within the BTC, westwards underneath the CPO and Lower Queen Street Separate works are being undertaken to continue the CRL tunnels from this point under the Downtown Shopping Centre site (which is to be redeveloped by Precinct Properties), and up Albert Street.

Significant works beneath the CPO will be undertaken, including diaphragm wall construction, piling and rail tunnel construction, along with a rebuild of the Basement 1 and ground floors. In Lower Queen Street, secant piling will be undertaken within the road corridor, along with excavation and concrete rail tunnel construction followed by reinstatement of the road corridor at the completion of works. During construction, existing ticketing and retail functions and pedestrian access to the station will be accommodated in a new temporary station building, located to the east of the CPO building.

Surface works will also be required in QEII Square associated with the Downtown Shopping Centre redevelopment, including construction of the CRL rail tunnels beneath this site (Precinct Properties scope of work).

Works commenced in July 2016 and are due to be complete by the end of August 2020. A detailed description of the construction works is provided in the CEMP.

2.2 Construction Zones

The Project will be divided into four discrete active construction zones (ACZ) as shown in Figure 2.1

Works required in the four ACZs are outlined in Table 2.1.

Table 2.1: Summary of key construction activities within each ACZ 1

Active Construction Zone

Key work components

A Britomart Station modifications

• Modification of existing platforms and track lines

• Installation of temporary access stairs, station entry and egress

B Accommodation within Station Plaza

• Construction of temporary accommodation buildings and facilities and relocation of ticketing, staff facilities, public amenities, retail/kiosk areas from the CPO building

• Installation of services

C CPO building works

• Removal of the CPO fixtures and fittings, including the timber floor

• Saw cutting and demolition of the concrete ground floor in the main ticket hall

• Installation of guide walls, diaphragm wall and underpinning structures to provide support for the CPO

• Soil excavation

• Construction of the base slab, walls and roofs for new rail tunnels

• Backfill excavation

• Reinstatement and fit out of CPO building

D Lower Queen Street

• Carry out piling and underpinning works

• Soil excavation

• Construct base slab, walls and roofs for new rail tunnels

• Backfill excavation

• Reinstatement of Lower Queen Street

Excavation of both Lower Queen Street and beneath the CPO will be conducted concurrently. The proposed excavations will extend approximately 16 m below ground level (bgl) beneath the CPO and Lower Queen Street with the excavations in Lower Queen Street extending approximately 28 m from the western edge of the CPO building. The works will result in an anticipated cut soil volume of 20,000 m3. The extent of excavation is shown on plans provided in Appendix B Spoil will typically be loaded directly onto trucks and transported from the site

A detailed description of the construction works is provided in the Project CEMP.

1 Note these activities are not in order of programme

3 Summary of contaminated land assessment

3.1

Overview

Contamination investigations conducted for the CRL Project to support obtaining the necessary planning approvals are documented in the following reports:

• City Rail Link Contaminated Land Assessment July 2012, prepared by AECOM;

• Auckland City Rail Link Britomart to Wyndham Contaminated Land Assessment December 2014, prepared by Golder Associates; and

• Auckland City Rail Link Britomart to Wyndham Water Quality Assessment December 2014, prepared by Golder Associates.

The contaminated land assessments undertaken for the Project comprised an assessment of soil, groundwater and ground gas. Limited soil testing had been carried out within the Project area with a single borehole (EB301) when the initial Contamination DWP was prepared in 2015 Since then additional soil sampling has been undertaken during enabling works.

A summary of the key findings of the assessment relevant to the Project is outlined in this section of the Contamination DWP.

3.2 Geology and Hydrogeology

Geology in the proposed excavation area comprise:

• Reclamation Fill below surface seal (asphalt and/or concrete). The fill is likely to comprise reworked natural soils and rocks (silts, sands, gravels and basalt), and waste materials (such as timber, metal, brick, concrete, ash, clinker, household refuse, and possibly gas works waste).

• Tauranga Group – alluvial sediments comprising silty clay with occasional wood fragments.

• East Coast Bays Formation – silty clay, clayey silt and sandy silt overlying alternating sandstone and siltstone beds.

Groundwater is expected to occur between 2 and 3 m bgl, with a likely tidal fluctuation ranging in the order of 1 m

3.3 Soil Quality

3.3.1

Original Data

For the preparation of the original Contamination DWP only two samples of the fill were collected during drilling activities for the installation of piezometer EB301. The samples, collected from 4.3 and 4.8 m bgl, show contaminant concentrations that comply with applicable NES Soil contaminant standards and the Auckland Council standards at the time being the Auckland Council Regional Plan: Air, Land and Water (ALW Plan) and the Proposed Auckland Unitary Plan (PAUP) permitted activity criteria.

As the assessment undertaken in the Project area was limited to two samples and based on the historic activities within the Project area, it was considered that soils with contamination above human health and environmental discharge assessment criteria may be present. In particular, the reclaimed foreshore beneath Britomart and QE II Square (including beneath the Downtown Shopping Centre) may contain hydrocarbons, metals/metalloids, asbestos, and gas works waste.

Additional sampling was undertaken by T+T during preparatory works between May 2016 and July 2018 to further characterise the material for disposal within the Project area prior to bulk earthworks. This additional sampling is described in Section 3.3.2 of this DWP

3.3.2 Additional Investigations

3.3.2.1 Investigation rationale and methodology

As reported in Tonkin and Taylors letter report dated 24th August 2018 2, 110 more soil samples have been taken for laboratory analysis from 35 locations across an approximately 3,500 m2 area

Samples were collected in conjunction with:

• Additional geotechnical investigations conducted for developed/detailed design purposes; and

• Preparatory ground breaking activities such installation of temporary works structures

Sample collection methods varied depending on the investigation methodology available, including collection from stockpiled spoil, directly from mechanical auger heads and recovered core. In all instances sampling was undertaken and overseen by suitably qualified and experienced contaminated land practitioners. Samples were collected directly into laboratory supplied sample containers, using freshly gloved hands, and despatched to IANZ accredited laboratories under standard chain of custody documentation. Samples were submitted, to Hill Laboratories, for analysis for a suite of heavy metals, polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH), cyanide and presence of asbestos.

3.3.2.2 Observations

The site observations were generally consistent with the geologic conditions detailed in Section 3.2. However, test pits excavated in the Lower Queen Street (LQS) area indicated basecourse and boulders and gravels to some 3m in depth.

Degraded hydrocarbon odours were noted in some sampling locations (S02, S12, S33, M13 and M18). These odours were noted within recovered core and during drilling typically within the marine sediments at the transition between fill and underlying Tauranga Group.

3.3.2.3

Evaluation criteria

Results have been compared to the NES Soil standard for commercial/ industrial land use and Permitted Activity (PA) criteria specified in Table E30.6.1.4.1 of the AUP to assess potential discharges to the environment. In addition, results have been compared to the background concentrations and acceptance criteria for a commonly used consented Managed Fill Site (Redvale Managed Fill 3) to assist in identification of disposal requirements.

2 Tonkin & Taylor, 24th August 2018, Central Rail Link - Contract 1, Summary of Soil Sampling Results - Update

3 Redvale Managed Fill Acceptance Criteria based on the published criteria dated 31/08/15 (Version 5) procedure document.

3.3.2.4 Soil quality investigation findings

Summary results tables are included in Appendix E Full discussion of results is presented in Tonkin and Taylor (2018)2

The key findings of the results compared with the regulatory assessment criteria are discussed below:

• All results are below the NES Soil standard for commercial/industrial land use with the exception of one arsenic concentration in the shallow fill at 1.6 m bgl at sample location S24.

• Analytical results largely comply with the PA discharge criteria as set out in the AUP. The exceptions include various heavy metal concentrations in 4 sample locations (BH502, S11, S12, S19 and S24).

• Asbestos was not detected in the 8 samples analysed for the presence of asbestos fibres.

The key findings of the results compared with the disposal criteria are discussed below:

• Reclamation fill, generally encountered to -1.5m RL, requires disposal to landfill; and

• Tauranga Group (alluvial and marine sediments), generally encountered to between - 1.5mRL and - 11.0mRL, requires disposal to managed fill

However, it was noted that acceptance criteria at individual disposal locations is site specific and at the discretion of the site operator. The necessary approvals/permits need to be obtained from the disposal destination prior to transportation of any materials from the site. Further, as well as contaminant concentrations, water content will dictate available disposal options and the landfill/managed fill operator should be contacted to discuss requirements.

3.4

Groundwater Quality

One groundwater sample collected from EB301 screened within the fill returned results below the relevant ANZECC (2000) trigger levels, indicating compliance with the Auckland Unitary Plan: Operative in Part (AUP) criteria

3.5 Ground Gas

Ground gas monitoring recorded carbon dioxide at 0.2 % v/v in EB301 during a single monitoring event on 6 November 2014. The measured concentrations were elevated above atmospheric carbon dioxide concentrations but below levels which represent a risk to human health. Oxygen levels were recorded within normal atmospheric range at sea level.

4 Mitigation and management of effects

4.1 General Mitigation Measures

The proposed mitigation and management of adverse environmental effects associated with contaminated and potentially contaminated fill within the Project footprint are detailed in this section of the DWP. The key mitigation and management measures that apply to the Project are summarised below:

Pre-works:

• Appoint a Contaminated Land Professional (CLP) prior to commencing work. The CLP shall be considered a ‘suitably qualified and experienced practitioner’ (SQEP) as required under the NES Soil. The CLP will be available to be present on site during all excavation works, and has responsibility for:

Co-ordinating contaminated land assessments and testing;

Advising on classification of excavated materials for reuse and disposal;

Co-ordinating groundwater management and disposal;

Training staff in contaminated fill identification and control procedures;

Liaising with the Health and Safety Officer during the excavation of contaminated fill; and

Supervision during any disturbance of contaminated fill

• Notify Auckland Council at least two working days prior to commencing any bulk earthworks on the site The following information will be provided to the Council’s Team Leader Earthworks and Contaminated Land, Natural Resources and Specialist Input:

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

Address of the site;

Description of works and expected duration.

During works

• Adherence to the Health and Safety procedures in Section 6 of this Contamination DWP to mitigate risks to construction workers and the general public in relation to the excavation of contaminated fill as defined in Section 4.4.1 of this DWP.

• Adherence to the management procedures for the excavation of contaminated fill set out in Section 5 of this DWP for:

Handling and storage requirements;

Measures to prevent the discharge of contamination; and Appropriate disposal of contaminated fill and appropriate treatment of potentially contaminated water

• Management of cleanfill and managed fill according to standard earthworks controls (dust and erosion and sediment control) and disposal to a site approved to take the fill.

• Following procedures for identifying and managing unexpected discovery of contaminated soils or hazardous materials.

• Restricting work areas if an unexpected discovery of contamination (above the NES Soil commercial/industrial land use soil contaminant standard) is encountered as per Section 7.1 of this DWP.

• Undertaking review and update of this DWP.

Post works

• Preparation of a Works Summary Report/Validation Report to establish measures complied with during the works.

The Project Communication and Consultation Plan, along with Section 5.3 of the CEMP, addresses methods for communicating with, and informing the public on works and activities occurring in the Project area.

4.2 Soil Contamination Effects

The testing of soil in the Project area has not detected contamination within the material to be disturbed above relevant human health assessment criteria, with the exception of one instance of an arsenic concentration in the shallow fill at sample location S24 exceeding the relevant criteria. It is noted that several soil samples within the shallow fill and one instance within the deeper fill included various heavy metal concentrations which exceeded the discharge PA criteria of the AUP.

4.3 Groundwater Contamination Effects

Previous investigations have not identified any significant contamination of groundwater within the Project footprint and there are no anticipated adverse environmental effects associated with groundwater. However, groundwater that is encountered during excavations (that requires removal for construction purposes) will be pumped into the Project’s water treatment and storage tanks before discharging to the stormwater system, thus mitigating any potential adverse environmental effects.

4.4 Soil Disposal

4.4.1

Soil Classification

Soils within the Project area will be classified into the following three categories to define management and disposal requirements:

Contaminated fill (as considered for both a human health and environmental risk for the Project Contaminated fill in the context of this Contamination DWP constitutes:

• Hazardous materials in the form of household and industrial waste, organic waste or asbestos containing material.

• Soil containing contaminants that exceed the AUP PA criteria specified in Table E30.6.1.4 or the NES Soil human health soil contaminant standard for commercial/industrial land use.

The opportunity for reuse is limited on the Project. However, should reuse be required/possible, reuse of contaminated fill on the Project will not occur without discussion with AC prior to placement. The location of any contaminated fill that is re-used within the project footprint will be surveyed (grid coordinates to be recorded) and the information will be provided in the Works Summary/Site Validation Report (refer Section 9 of this DWP). (Note: An additional resource consent may be required to reuse contaminated material on site)

Managed fill (as considered for disposal purposes)

Managed fill comprises:

• Soil containing low level metal contaminants (i.e. above the published background concentrations in the Auckland region for non-volcanic soils).

• Soil containing low level hydrocarbon compounds.

• Soil that does not contain hazardous substances or materials in the form of household and industrial waste, organic waste or asbestos containing material.

Cleanfill (as considered for disposal purposes)

Cleanfill is defined in Condition 88 of discharge permit R/REG/2014/5435 by reference to the Ministry for the Environment (MfE) Document ‘A Guide to the Management of Cleanfills’ (2002), which states that:

“..material that when buried will have no adverse effect on people or the environment; and includes virgin materials such as clay, soil and rock, and other inert materials such as concrete or brick that are free of:

• Combustible, putrescible, degradable or leachable components

• Hazardous substances

• Products or materials derived from hazardous waste treatment, hazardous waste stabilization or hazardous waste disposal practices

• Materials that may present a risk to human health

• Liquid waste.”

In simple terms, cleanfill includes materials such as uncontaminated soils, cured asphalt, bricks, unreinforced concrete, fibre cement building products (excluding asbestos) and glass

Non-cleanfill materials would include soils with analytical results showing potential detectable hydrocarbon compounds and/or exceedance of Auckland Region background concentrations of metals, asbestos-containing materials and new asphalt.

4.4.2 Site specific soil disposal requirements

The conservative approach to soil management detailed in the original Contamination DWP for excavation within reclamation fill required all excavated fill to be treated as contaminated and disposed of to an appropriately licensed solid waste landfill (unless proven otherwise by soil testing).

Based on the additional testing undertaken as detailed in Section 3.3.2 of this DWP, disposal options are shown in Table 4.1.Disposal options presented rely on construction/excavation methodology to enable clear identification and segregation of the separate materials.

Table 4.1: Summary of potential disposal options

Section 4.4.1)

East Coast Bays Formation Cleanfill

Fill**

Section 3.2)

- 1.5mRL and - 11.0mRL and below the CPO B2 floor slab footprint where marine sediments are potentially present to - 14mRL.

below -11.0mRL and below -14mRL within the CPO B2 floor slab footprint

Note: 1Acceptance criteria at individual disposal locations is site specific and at the discretion of the site operator. The necessary approvals/permits shall be obtained from the disposal destination prior to transportation of any materials from the site.

The necessary approvals/permits shall be obtained from the disposal destination prior to transportation of any materials from the site. All weighbridge dockets and a summary sheet shall be retained for inclusion in the site closure Works Summary/Validation Report (refer to Section 8 of this DWP).

4.5 Soil sampling and testing

Further sampling and testing of soils within the Project footprint has been undertaken (as detailed in Section.3.3.2 of this DWP) prior to the commencement of bulk earthworks in order to classify soils for management and removal.

Any additional soil sampling will be undertaken under the supervision of the CLP according to the requirements of the NES Soil Regulations and the MfE Contaminated Land Management Guidelines No.5 4 . Soil samples shall be collected according to the following procedure:

• Representative samples of the reclamation fill and natural soils;

• 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;

• Freshly gloved hands shall be used 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.

The CLP will evaluate any analytical results with respect to the soil classification categories identified in Section 4.4.1 of this DWP The following basic principles will be adopted to define which materials are cleanfill, managed fill or contaminated fill:

• Assume to mid-point where cleanfill and managed fill locations are adjacent to each other;

4 MfE, revised 2011: Contaminated Land Management Guideline No. 5 – Site Investigation and Sampling.

• Assume to mid-point where managed fill and contaminated fill locations are adjacent to each other; and

• Assume contaminated fill extends to the cleanfill location.

However, the CLP will review the geological information and the contaminant concentrations of the samples. Depending on the results of the review and the final disposal or placement location of the excavated soil, the CLS may instruct the on-site workers to adopt a variation of the basic principles outlined above.

4.6 Imported material requirements

In the event that any fill or soil is required to be imported to the site, the materials shall comprise either:

• Granular materials, which are sourced directly from a licensed quarry. Such material will not require testing, provided documentation confirming the source of the material is kept; or

• If soil needs to be imported, then any imported soil shall:

Comply with the definition of 'cleanfill' in the MfE publication 'A Guide to the Management of Cleanfills’ (2002) (refer Section 4.4.1 of this DWP);

Be of a solid material of an inert nature; and/or

Be sampled by a suitably qualified CLP at a rate of 1 sample for every 500 m3 and tested to confirm that contaminants are not above published natural background levels of the site It is preferable if the soil is tested at its source prior to its placement at the site. If not, the materials shall be stockpiled on site until test results are available.

4.7 Sealing Excavation Service Trenches

If contaminated fill is encountered, and sealing of service trenches is consequently required to prevent them from acting as a conduit for migration of contaminated groundwater away from the site, then a pipe dam will be installed at the boundary of the Project footprint. The pipe dam will be either concrete or some other impervious material to be specified by the drainage design engineer. The dam will encase the pipe and extend up the trench to just below the paved surface as shown in Figure 4 1 below

The locations of pipe dams will be recorded on as-built drainage drawings for the Project area.

5 Contaminated Fill Management

5.1 Overview

This section details the procedures for the management of contaminated fill during earthworks. It includes control measures for reducing human exposure to contaminated fill and minimising contaminated discharges to air, land or water. These measures will be established prior to commencement of bulk earthworks in areas of known contamination.

5.2 Excavation of Contaminated Fill

The following protocols shall apply to the excavation of contaminated fill (as defined in Section 4.4.1):

• Erosion and sediment controls shall be implemented in accordance with the Project Erosion and Sediment Control Plan (ESCP) (refer to Appendix M of the CEMP) before earthworks commence.

• Excavated soil shall be placed directly into a truck for immediate off-site disposal to prevent the potential for cross contamination of soils

• Any soils retained on site as part of contingency storage (e.g. during night works) shall be placed in a designated area, contained within the catchment area of the erosion and sediment controls for the site or appropriately bunded and covered with polyethylene or an equivalent impermeable material so as to minimise emission of particulates and stormwater runoff.

• Any spillages of contaminated fill during placement in trucks shall be cleaned up as soon as practicable following the spillage. Spillages shall not be left unattended as contaminated fill could be trafficked by trucks and transported onto the public road network

• The earthworks shall be observed by the CLP

5.3 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. Any contact between clean stormwater or perched groundwater and potentially contaminated fill/spoil means the water will likely require treatment prior to discharge to the stormwater network.

To minimise the potential for clean stormwater to encounter potentially contaminated fill, the stormwater and sediment controls outlined in the Project ESCP shall be implemented during the earthworks.

In the event that clean stormwater or perched groundwater comes in contact with potentially contaminated fill, the water shall either be disposed of by a licensed liquid waste contractor or pumped to sewer (subject to approval by Watercare Services Limited).

Discharge to stormwater shall only be allowed to occur if the average concentration of samples of effluent collected by the CLP from the outlet of the stormwater treatment system on a daily basis for three consecutive days complies with 50 times the ANZECC ‘Guidelines for Fresh and Marine Water Quality’ (2000) for the protection of marine water species. Table 5.1 provides the stormwater disposal acceptance criteria for common contaminants.

Discharge to stormwater shall not be allowed to occur prior to the testing or if the average concentrations do not comply with the acceptance criteria.

Table 5.1: Stormwater disposal

Hydrocarbons - No sheen

5.4 Dust Management

Works in the CPO will be undertaken inside the building so that dust controls will only be required to protect workers. Measures to mitigate dust issues are likely to comprise wetting the contaminated fill and the use of dust masks by workers inside the building.

The following controls shall be implemented during extraction of contaminated fill in the Lower Queen Street ACZ (ACZ-D as shown in Figure 2.1 of this DWP):

• 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.

• 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.

• 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 conditions are favourable.

Further dust management and monitoring requirements are set out in the project Air Quality DWP (Appendix L of the CEMP).

5.5 Odour Management

The contaminants in soil and groundwater, particularly during excavation in the transition between fill and underlying alluvial and marine sediments of the Tauranga Group, may generate odours and potentially vapours. If odorous material is encountered, then the actions outlined in Section 7.1 of this DWP shall be implemented. Further odour management and monitoring requirements are set out in the project Air Quality DWP (Appendix L of the CEMP).

To prevent odours from causing an effect beyond the boundary of the Project work site, management procedures will include, but not be limited to, the following:

• Limiting the time that the excavation of odorous materials is exposed;

• Removing excavated odorous material from the site as quickly as possible; and

• The use of odour masking agents, chemical counteractants and digestive odour deodorant sprays.

If significant odour is detected and the odorous material cannot be removed quickly, and odour masking agents, chemical counteractants or digestive deodorant sprays are not immediately available, the odorous material will be covered, and work in that area suspended until suitable mitigation measures can be put in place.

5.6 Decontamination

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

• Any excess soil on vehicle tyres shall be removed before vehicles leave the works area.

• Excess soil shall be removed from vehicles and plant before they leave the works area.

• All trucks transporting excavated soil to the selected disposal facility shall be covered to prevent the spillage of soil and dust emissions.

The Project team shall be responsible for both monitoring and cleaning up any soil that is deposited onto public roads or walkways from the Project.

5.7 Monitoring Programme

Regular visual inspections of the earthwork areas will be carried out by the Site Manager or appointed person as follows:

• Sediment control and compliance with this Contamination DWP (at least daily);

• Dust and odour generation (at least daily)

• Water accumulation (at least daily);

• Perimeter fencing (at least weekly);

• Evidence of olfactory and/or visual contamination of fill material (all loads); and

• Access road surface deterioration (at least weekly).

All stormwater facilities will be inspected after heavy rain events. Inspections are to identify any blockage which reduces the capacity of the drain; and any erosion or scouring which creates silt and damages the drain.

Maintenance to ensure the effectiveness of the control measures will be carried out if the inspections show that this is required.

Methods that shall be used to address any breaches of the stormwater system, or any discharges onto soil, are provided in Sections 7.1and 7.3 of this DWP.

The CLP will also observe the Project works on a regular basis during all ground disturbance activities in order to check compliance with this Contamination DWP.

6 Health and Safety Procedures

6.1 Overview

This Contamination DWP provides procedures for site personnel working in and around contaminated and/or potentially contaminated fill during the excavation works. The procedures are not intended to relieve CRLL, or DSBJV, 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.

Daily health and safety toolbox meetings will be undertaken and documented.

All parties working on the project shall comply with:

• Applicable parts of their Company Health and Safety Policy.

• Site-specific Health and Safety Plan.

• Any requirements of Worksafe New Zealand.

• Health and Safety at Work Act 2015.

• Any other applicable legislation, regulations, codes and guidelines, including any new relevant regulations that come into force during the Project

Sub-contractors engaged on the Project are required to provide their own Job Safety Assessment (JSA) for their equipment and workers to the DSBJV for approval prior to the commencement of their works on-site. Sub-contractors are also required to supervise the health and safety of their staff on the Project

6.2 General Safety Requirements and Training

All Project staff (including sub-contractors) shall be required to participate in a site environmental and sustainability induction, which includes a review of procedures with respect to site contamination. The induction shall be provided such that all relevant personnel understand, prior to commencing work, what procedures are to be implemented in relation to site contamination and why. The purpose of the induction is to educate the workers with respect to the hazards associated with contaminated fill, safe working procedures, safety equipment and requirements, and the response plan in the event of an emergency.

An appropriately qualified Health and Safety Officer (HSO), or similar, shall be appointed for the duration of the works. This will ensure 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 designated HSO shall ensure that all relevant personnel are familiar with the application and use of required personal protective equipment (PPE) and procedures specified in this 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 project construction zone:

• 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.

• Site personnel shall avoid unnecessary contact with documented and potentially contaminated fill and groundwater.

• Site personnel who may come into contact with contaminated fill shall be provided with the minimum level of PPE as defined in Section 6.7 of this DWP

6.3 Control Measures

When considering hazard controls, the hierarchy listed below will be followed, in preference from one to five. Example questions are provided to illustrate each step.

1 ELIMINATION – does the task that creates the hazard need to be performed?

2 SUBSTITUTION – can a different tool be used?

3 ENGINEERING – can the hazard be guarded to protect people?

4 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:

a Job Safety Analysis (JSA) or Task Analysis.

b Work plans.

c Training.

d Warning signs.

e Communication with the Site Manager/HSO.

5 PERSONAL PROTECTIVE EQUIPMENT – is the appropriate PPE being used? The following is noted:

a PPE is considered the lowest level of protection against a hazard.

b No single combination of protective equipment and clothing can provide protection against all hazards; PPE should be used in conjunction with other protective methods.

c 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

This DWP identifies potential hazards associated with the presence of soil contamination and recommends procedures to mitigate these risks. Contaminants in reclamation fill materials could include metals/metalloids and hydrocarbons. Other hazards that may be identified during pretesting of the material or during the works are outlined in Section 8 of this DWP

Potential exposure routes for contaminants include:

• Inhalation of dust (potentially contaminated and uncontaminated).

• Ingestion of potentially contaminated fill or dust.

• Dermal absorption of potentially contaminated fill or dust.

• Skin and eye contact with potentially contaminated fill or dust.

6.5 Identification of New Hazards

There is the potential for additional hazards to be identified and encountered during the project. 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 CLP 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 outlined in Section 5.4 of this DWP. The following additional measures shall be considered to minimise inhalation of dust:

• Monitor wind speed and direction during earthworks;

• Workers involved in excavation activities will stand up wind of excavation and vehicle loading areas during windy conditions, where practicable; and

• If exposure to dust cannot be prevented dust masks shall be worn.

6.6.2

Vapour inhalation

It is conservatively considered that volatile contaminants could be present in the transition between fill and underlying alluvial and marine sediments of the Tauranga Group Mitigation of vapour risk will be achieved as follows:

• If there are olfactory indications for vapours or vapours are suspected, the following monitoring shall occur:

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 (refer Table 6 1), work shall stop, the area vacated and the CLP and/or HSO shall be informed. A respirator shall be worn when re-entering the area to re-test the atmosphere. The appropriateness of the trigger level of 50 ppm shall be reviewed by the CLP, depending on the type of contaminants found within the project area.

Lower explosive limit (LEL), oxygen levels shall be checked with a gas meter prior to entering and working within confined spaces Work shall not commence/continue if levels exceed the triggers set out in Table 6 1 The area shall be vacated and the CLP and/or HSO shall be informed to provide advice.

• Work shall not resume unless approved by the Site Manager in consultation with the CLP/HSO.

Table 6.1: Gas trigger levels

Compound Trigger level

VOC

LEL

Oxygen

Greater than 50 ppm

Greater than 0% if hot work is proposed

Greater than 10% if cold work is being undertaken

Below 19.5% and above 23.5%

Hydrogen sulphide (H2S) Greater than 10 ppm

Carbon dioxide (CO2) Greater than 5,000 ppm

Carbon monoxide (CO) Greater than 25 ppm

Note:

Refer Appendix D, response to IPR comments s6.6.2, for rationale for VOC trigger LEL trigger is based on Department of Labour, Safe working in a Confined Space (http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/confined-space-safe-working-ina/confined%20space.pdf)

Oxygen, H2S, CO2 and CO triggers are based on Ministry of Business, Innovation & Employment, Feb 2013, Workplace Exposure Standards and Biological Exposure Indices

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:

• Disposable gloves shall be worn by personnel who need to have contact with contaminated fill 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 fill to contact other parts of the body (legs, arms etc.).

• There shall be no eating, drinking or smoking in the works area to prevent contaminated fill contacting food or being ingested directly via soiled hands 5

A key factor in controlling dermal contact and ingestion of contaminated fill 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 and face 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.

• 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 fill shall wear the following PPE to protect against the above risks:

• Overalls or disposable coveralls.

• Impermeable gloves (tear resistant if appropriate).

• Disposable dust masks will be available to workers for use if dust is being generated.

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 by DSBJV for noncontamination related health and safety.

5 One exception to this is the need for closed water bottles in the excavation to ensure site staff are adequately hydrated. So long as the bottle is sealed, there should be minimal potential for the ingestion of contaminants.

7 Contingency actions

7.1 Unexpected discovery of contamination

If evidence of contaminated fill or hazardous material is encountered during earthworks, work in the area of concern shall cease until the CLP 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).

• Fibrous cement based board materials that may contain asbestos.

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

• Cease all work within a 20 m radius and make the work area safe and restrict access to all workers until instructed by the Site Manager

• Shut off all ignition sources and, if possible, contain any contaminant discharge and close/divert any water flow

• Advise the Site Manager.

• Work shall not resume until the ‘all clear’ is given by the Site Manager.

• The Site Manager (in consultation with the CLP) shall assess the site. If the assessment concludes that confirmation of contamination is required, the following actions shall be implemented:

Control the site: install temporary fencing, temporary cover, silt traps and bunding as required around the area of potential contamination.

Small volumes of excavated contaminated fill shall be contained in covered skips to minimise contaminated discharges from rainfall runoff and dust. If this is not possible, larger volumes shall be covered and bunded to manage dust and storm water runoff

Potentially contaminated water shall be collected and disposed of to an appropriately licensed treatment facility. It must not be discharged to the construction storm water system.

Samples of the suspect contaminated fill shall be collected (by appropriately trained and qualified personnel) for laboratory analysis using appropriate procedures. Notify Auckland Council as soon as practicable.

• The results of the laboratory analysis shall be assessed against the relevant human health and environmental discharge regulatory standards/acceptance criteria as appropriate.

• If asbestos fragments are encountered in the reclamation fill, earthworks shall follow: Health & Safety at Work (Asbestos) Regulations 2016; Approved Code of Practice Management and Removal of Asbestos November 2016; New Zealand Guidelines for Assessing and Managing Asbestos in Soil published November 2017; and

Any other current guidance document or current updated versions of the above.

Asbestos is a human health related contaminant and no environmental effects are known to be associated with asbestos. Thus, the works will be undertaken in a manner that will protect human health of the workers undertaking the work and the general public in the vicinity of the area. The main aim will be to prevent the generation, and hence inhalation, of airborne asbestos fibres. To mitigate against dust generation, any exposed asbestos or soil containing asbestos shall be kept damp at all times until it is covered, for example placed into bags or a covered metal skip bin or covered by polyethylene. The work involving friable asbestos shall be supervised by a competent person as defined by the Health & Safety at Work (Asbestos) Regulations 2016. All asbestos and any soil containing asbestos shall be appropriately encapsulated or disposed to a landfill approved to take the material.

• Remediation options will be selected using the following sustainability hierarchy, refer to Appendix C for the appraisal tool:

1 If practical, on site treatment of the contamination so that it is destroyed or the associated risk is reduced to an acceptable level

2 Offsite treatment of excavated contaminated fill so that the contamination is destroyed or the associated risk is reduced to an acceptable level, after which the treated soil is returned to the site

3 Consolidation and isolation of the contaminated fill is on site by containment with a properly designed barrier

It should be noted that if the contaminated fill is proposed to be encapsulated in another area of the project (i.e. not in the area where the contaminated fill was discovered), then further resource consent and approval from Auckland Council is required.

4 Removal of contaminated fill to an approved site or facility, followed, where necessary, by replacement with appropriate material

5 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.

• The CLP will be consulted on the handling and management of contaminated fill 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 contaminated fill requiring off-site disposal must be disposed of at facilities consented to accept the material.

• Maintain a register of any contaminated fill discovered, including location, type, quantity and disposal record (landfill receipts and waste manifest).

7.2 Complaints procedure

Procedures for handling a complaint are set out in Section 12 of the Project Communication and Consultation Plan and Section 5.3.1 of the CEMP The following actions shall be undertaken for ground contamination-related complaints.

• A written record of all ground contamination related complaints received shall be maintained.

• The Site Manager shall initiate an investigation as soon as practicable on receipt of a complaint, but as a minimum shall notify Auckland Council as soon as practicable of the complaint being received, including providing details of any corrective actions taken.

• Appropriate feedback will be provided to the complainant, such as the response made and any corrective actions taken, in response to the complaint.

7.3 Water discharges

Should an incident occur on-site which may result in any unauthorised discharges (e g contaminated water to stormwater and/or to soil), the Site Manager and/or Environmental and Sustainability Manager will take control of the situation and coordinate the efforts of site personnel to minimise any adverse impacts. 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, including, but not limited to:

1. Using tanker trucks to pump out contaminated water;

2. Improving effluent quality through additional treatment; and/or

3. Discharge to sewer, subject to removal of sediment and issue of any necessary temporary trade waste permits. However, diversion to tradewaste cannot be assumed to be available.

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

If contaminated water discharges onto soil, further testing of the impacted soil may need to be carried out. Soil samples shall be collected by the CLP according to the requirements of the NES Soil, the MfE Contaminated Land Management Guidelines No.5. 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”. The CLP shall identify potential contaminants on the basis of visual and olfactory observations.

8 Works Summary/Validation Report

On completion of the soil disturbance works, a Works Summary Report (also referred to as a validation report) will be prepared and provided to Auckland Council. The purpose of the Works Summary / Validation 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 CLP.

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 Contamination DWP;

• The location and dimensions of the excavations carried out, including the location, depth and volumes of contaminated fill, managed fill and cleanfill that required disposal and location of any contaminated fill re-used within the Project footprint;

• Copies of the disposal dockets for the contaminated fill, managed fill and ‘cleanfill’ material removed from the site;

• Records of all inspections undertaken by the CLP during disturbance works of contaminated fill;

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

• A summary of soil, perched water and groundwater testing undertaken (if applicable) including tabulated analytical results, and interpretation of the results in the context of the Contaminated Land Rules of the AUP;

• Details regarding any complaints and/or breaches of the procedures;

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

• Results of testing of any imported fill material; 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.

The Works Summary / Validation Report shall comply with the MfE Contaminated Land Guideline No. 1 - Guidelines for Reporting on Contaminated Sites in New Zealand.

9 Review and Updating of

the DWP

The original Contamination DWP has undergone a review process with the Community Liaison Group (CLG) established for the Project and a suitably qualified independent peer reviewer. An explanation of how any comments from the CLG and independent peer reviewer are addressed in the Contamination DWP is provided in Appendix D.

9.1 DWP Review

This Contamination DWP will be reviewed throughout the course of the Project:

a To reflect material changes associated with changes to construction techniques, the natural environment or due to unresolved complaints.

b As part of the annual management review of the DWP.

The management review of the DWP will be undertaken at least annually by the Project Management team and the CRLL representatives. The management review will be organised by the Environmental and Sustainability Manager and the Project team will be informed of any changes to this DWP through the regular Project communications processes. The review will take into consideration:

• Compliance with the designation or consent conditions, the CEMP, DWPs and EMPs (including site specific plans) and material changes to these plans.

• Any significant changes to construction activities or methods.

• Key changes to roles and responsibilities within the Project team.

• Changes in industry best practice standards.

• Changes in legal or other requirements (social and environmental legal requirements, consent conditions, CRLL objectives and relevant policies, plans, standards, specifications and guidelines).

• Results of inspections, monitoring and reporting procedures associated with the management of adverse effects during construction.

• Comments or recommendations from Auckland Council regarding the CEMP, DWPs and EMPs.

• Unresolved complaints and any response to complaints and remedial action taken to address the complaint.

9.2 DWP Updates

The process for updating this DWP as a result of a material change to the Project or the annual review, is as follows (refer to CRL designation Condition 23 for further information):

• Any material change to this DWP must be consistent with the purpose and objective of the relevant conditions listed in Table 1.1 of this document.

• Affected parties and the CLG must be notified of the review and any material change proposed to this DWP.

• This DWP must clearly document the comments and inputs received from affected parties in relation to any material changes, along with a clear explanation of where any comments have not been incorporated, and the reasons why not.

• Any material change proposed to this DWP shall be subject to an independent peer review as required by CRL Condition 11.

Any material change proposed to this DWP relating to an adverse effect shall be submitted for approval to Auckland Council Compliance and Monitoring Officer, at least 10 working days prior to

the proposed changes taking effect. If any changes are not agreed, the relevant provisions of the RMA relating to approval of outline plans shall apply.

A copy of the original Contamination DWP document and subsequent versions will be kept for the Project records, and marked as obsolete. Each new / updated version of the Contamination DWP documentation will be issued with a version number and date to eliminate obsolete Contamination DWP documentation being used.

A summary of the review process will be provided annually to Auckland Council and otherwise be made available on request.

10 Management and Control of Documents

All project documentation is created, reviewed, approved, issued, revised, retained, and superseded in accordance with the project’s Document Management & Control Plan, which includes the requirement for records of review and authorisation to be maintained.

The following project-specific documents need to be created to support the processes described in this plan:

1. Project Induction

1.1. Full Induction Presentation Content

1.2. Full Induction Register

1.3. Visitor Induction

2. Site Inspection Records

2.1. Daily visual inspections

2.2. Weekly E&S site inspection forms

2.3. Monthly E&S site inspection forms

2.4. Corrective action tracking register

3. CLP observations records

4. Contamination remediation sustainability appraisal

5. Soil Sampling

5.1. Additional soil sampling results

5.2. Imported fill sampling results

6. Soil Disposal

6.1. Approvals/permits from the disposal destination

6.2. Weighbridge dockets

6.3. Summary sheet

7. Discharge sampling from water treatment plant

8. Works Summary Report

9. Review

9.1. Annual CLMP review record

Applicability

This report has been prepared by Tonkin & Taylor Ltd for the benefit of the Downer Soletanche Bachy Joint Venture with respect to Contract 1 of the CRL Enabling Works. This report has been prepared with respect to the particular brief given to us and it may not be relied upon in other contexts or for any other purpose without our prior review and agreement.

Recommendations and opinions contained in this report are based on previous investigations and monitoring data. The nature and continuity of the subsoil away from the test and sample locations is inferred but it must be appreciated that actual conditions may vary from the assumed conditions.

Report certified by a suitably qualified and experienced practitioner as defined by the NES Soil Users Guide (April 2012):

Elyse

LaFace

Lean

Phuah

Environmental Scientist Senior Contaminated

Land Specialist

Authorised for Tonkin & Taylor Ltd by:

Neil Korte Project Director

Appendix A : ISCA Requirements

Table A identifies the ISCA Credit Requirements relevant to this Contamination DWP and where they are addressed in the document.

Table A: ISCA Requirements

ISCA Credit ISCA Requirement * Relevant section Other relevant information

LAN-3 Level 1 Site assessment follows recommended approach

This document

LAN-3 Level 2 Remediation options are identified and selected using sustainability indicator as detailed and using a multicriteria analysis or other scored or quantified means. Appendix C

LAN-3 Level 2 Site assessment work audited by qualified independent specialist N/A

• A site investigation has been completed for the Project - refer Section 3 of this DWP and the following reports:

- City Rail Link Contaminated Land Assessment July 2012, prepared by AECOM;

- Auckland City Rail Link Britomart to Wyndham Contaminated Land Assessment December 2014, prepared by Golder Associates; and

- Auckland City Rail Link Britomart to Wyndham Water Quality Assessment December 2014, prepared by Golder Associates.

• As outlined in Section s 3 and 4 of this DWP, the sampling of the Project area undertaken to date has identified that ground material largely complies with applicable NES Soil contaminant standards and only some exceedances of AUP permitted activity criteria within material to be excavated

• Further site investigations have been undertaken prior to the commencement of excavation as outlined in Section 4 of this DWP.

• Ongoing monitoring and further sampling will continue during excavation as outlined in Sections 5.4, 5.5 and 6.7 of this DWP

• Supervision by a Contaminated Land Professional will occur when excavating in areas suspected of being contaminated (refer to Section 5.1 of this DWP).

• Sampling identified material that largely complies with applicable NES Soil contaminant standards and only some exceedances of AUP permitted activity criteria within material to be excavated.

• As contaminated material has been identified, the Contamination Remediation Options Appraisal (Appendix C) will be completed.

• This will be completed as part of resource consenting process for this Project.

* Refer to ISCA Rating Tool for full details of the requirement

Appendix B : Plans of Works

Appendix C : Soil Remediation Appraisal

If any unexpected discovery of contaminated soil is encountered during the Project, it will be managed using the ISCA sustainability hierarchy approach. Soil remediation and management options will be assessed in accordance with a rating tool and the following multiple category assessment table will be used to complete this:

Appendix D : CLG and Independent Peer Review Comments

Community Liaison Group Comments

Comments received from the CLG are as follows. Note that section references are as per the original Contamination DWP.

Date CLG Member Comment Response

24th November 2015

24th November 2015

24th November 2015

Kathy Ross Will soil monitoring release contaminants into the atmosphere?

Kathy Ross Will dust from contaminated material be toxic?

Peter Bowden Will contaminated material be disposed of at the Three Kings Quarry?

4 May 2016 Cooper and Company

4 May 2016 Cooper and Company

Section 4.1, General Mitigation Measures, states that AC will be notified at least “2 days” prior to commencing any contaminated works or bulk earthworks on site. Condition 83 (RC) refers to 2 “working days” the plan should be amended to reflect this. In the post works section it refers to the production of a “Works Completion Report”. However, elsewhere the terms “Works Summary” or “Validation Report” are used. The conditions used the term “Works Completion Report” suggest amending reference in this section to that term for consistency/clarity.

Section 4.6, Imported Material Requirements refers to any imported fill complying with the definition of clean -fill and not containing contaminants above the natural background levels. However, condition 91 (RC) also requires that any fill be solid material of an inert nature. Might be helpful to specify that in this section too.

Monitoring will be undertaken to inform the appropriate disposal method for contaminated material – no change to DWP required.

Based on contaminant levels identified to date and historical information, any dust will be from natural or inert (non-toxic) material – no change to DWP required.

Based on existing information yes but further soil testing is required to confirm the disposal location – no change to DWP required.

Section 4.1 General Mitigation Measure’s text updated to 2 working days.

Condition 93 and 94 of the regional discharge permit refers to a Works Summary Report. Condition 58.1 of the CRL Designation refers to Validation Report. We could not find a condition that used the term “Works Completion report”. We have amended text thought the DWP to refer to Works Summary / Validation report for consistency and clarity.

4 May 2016 Cooper and Company

Section 6.1, Overview, refers to new Health and Safety at Work Act “which will come into force on 5 April 2016”. Update to

Section 4.6 text updated to refer to condition 91 (RC) requirement that any fill be solid material of an inert nature

Section 6.1 text updated to refer to the current status of the Health and Safety at Work Act.

4 May 2016 Cooper and Company

18 May 2016 Cooper and Company

reflect it came into force on that date.

Section 9, Review and Updating of the DWP, sets out the formal review process. This section mentions providing outcome of the annual review process to council but does not mention consultation with CLG. Condition 19 states that the consent holder is required to consult with the CLG upon the review of this plan. Reference should be included here of this obligation.

Section 5.4 Dust Management, there is a typo “exaction” should be “extraction”.

• Independent Peer Review Comments

Section 9 text has been updated to reference Condition 19 requirement to consult with the CLG upon the review of this plan.

Section 5.4 text updated to correct typo.

An Independent Peer Review of the draft Contamination DWP was undertaken by Terre Maize from 4Sight Consulting, with peer review comments received on 5th February 2016. The comments received are as follows. Note that section references are as per the original Contamination DWP.

Section of DWP

Comment

4.1 Section number reference is missing with regard to Communication and Consultation Plan and CEMP. The designation condition requires crossreferences to specific sections of the Communication and Consultation Plan, and the text says “along with Section xx of the CEMP…”

4.4 There is reference to “an appropriately licensed municipal solid waste landfill” with regard to disposal of contaminated soil. Typically, “municipal solid waste landfill” is the term used for the municipal landfill which accepts general rubbish; e.g., household rubbish. It would probably be more clear if the word “municipal” was removed from the sentence.

4.6 While it is not required that the Contract 1 and Contract 2 plans match, the Contract 2 plan specifies testing of imported material at a rate of 1 sample per 100 cubic metres and the Contract 1 plan specifies testing at a rate of 1 sample per 500 cubic metres. The frequency of sampling is dependent on the source, type and homogeneity of the material imported. It would be

Response

The Communication and Consultation Plan section reference will be included once that plan is finalised, and prior to finalisation of this Contamination DWP

The word municipal has been removed.

Only cleanfill is proposed to be imported and this would be reflected in the selection of the source site and material. Material that requires a high level of testing (e.g. 1 in 100 cubic metres) should not be considered cleanfill and would not be considered in the first place.

Section of DWP Comment Response

beneficial to note the rationale for the selection of the sampling frequency for imported material.

5.7 It would be helpful to describe what (if any) methods will be used to address breaches of the stormwater system and any validation sampling requirements in the event of a breach that discharges onto soil.

6.6.2 While it is not required that the Contract 1 and Contract 2 plans match, there are areas where they should be consistent. The Contract 1 plan sets a limit of 5 ppm for VOCs (measured with the PID). The Contract 2 plan establishes a limit of 50 ppm VOC as measured by the PID. Typically, at concentrations between 5 and 50 ppm VOC, respiratory protection is required. It would be useful to also note this in the Contract 1 plan as this would make them more consistent and better reflect requirement s. The Contract 2 plan also sets out limits for LEL, oxygen, hydrogen sulphide, carbon dioxide and carbon monoxide. The likely contaminants may be different enough that this is not warranted for Contract 1 plan, but it is recommended that it be considered.

Additional information is provided in Sections 5.7 and 7.3.

6.6.3 It would be good to state that “hands and face” (not just “hands”) should be washed to reflect industry good practice.

7.2 Please include the section number for the Communication and Consultation Plan.

PIDs are not contaminant specific and will therefore detect all ionisable compounds that are present in the air space of the work area.

The proposed trigger set in the DWP, of 50 ppm, is based primarily on cumulative experience with using the PID working across sites with mixed hydrocarbon contamination. The derivation of this action level was based on balancing the highly variable effects thresholds and response factors of a wide range of potential contaminants e.g. benzene at 1 ppm to petrol at 300 ppm, and higher for some of the other hydrocarbons. Since benzene is rarely present at elevated concentrations, 50 ppm provides a workable yet conservative compromise. Using a much lower level of 5 ppm, is likely to result in false exceedances of the action level as a result of detection of compounds, which are present at higher, although still safe concentrations, or the detection of compounds introduced by other activities which are being undertaken within or adjacent to the work area (for example vehicle exhaust emissions, use of glues, solvents, or paints etc.).

This action level should be reviewed by the CLP to ensure it remains appropriate. This recommendation has been added to Section 6.6.2. Trigger levels for the contaminants have been included in Section 6.6.2.

The word “face” has been added.

The Communication and Consultation Plan section reference will be included once that plan is finalised, and prior to finalisation of this Contamination DWP

Appendix E : Summary results tables

Appendix F : Register of Plan Updates

• Annual Reviews

Updates

Updates have been made to the following sections:

• Section 1.5 – addition of information about the reviewer of the contamination DWP.

• Section 2.1 – change in method from sheet piling to secant piling in LQS. Slight amendments to the description of the works.

• Table 2.1 – delete reference to processing concrete onsite for use as backfill as this is no longer proposed.

• Section 3.1/3.3 – amended to reflect additional soil sampling undertaken since the last revision of this plan.

• Section 3.4 – amendment to the referenced plan.

• Section 4.0 – new section which describes the additional soil sampling that has been undertaken between May 2016 and September 2017, site observations and an evaluation of sampling results.

• Section 5.2 (previously 4.2) – change to soil contamination section based on more recent sampling results.

• Section 5.4 (previously 4.4) – approach to soil disposal amended following additional testing. Previously all excavated fill was to be treated as contaminated. Summary of potential disposal options is presented based on additional testing results.

• Section 5.4.1 (previously 4.4.1) – change of reference to regional plan criteria

• Section 5.5 (previously 4.5) - amended to reflect additional soil sampling undertaken since the last revision of this plan.

• Section 6.2 (previously 5.2) – deleted reference to contamination only being present in the reclamation fill.

• Section 6.5 (previously 5.5) – addition of detail around where odourous material may be found based on site observations during additional sampling.

• Section 6.7 (previously 5.7) – deleted reference to weekly site observations by CLP during bulk earthworks of the reclamation fill, as CLP may be required on a more regular basis and this is covered in the previous sentence.

• Section 7.6.2 (previously 6.6.2 – addition of detail around where volatile contaminants may be found based on site observations during additional sampling.

• Section 8.1 (previously 7.1) – amendment to relevant regulations.

• Section 9 (previously 8) - change of reference to regional plan

• Section 11 – new section summarising project-specific documents that are required to support the processes described in this plan.

• Appendix A – Update to Table A to reflect results of additional soil sampling undertaken since the last revision of this plan.

• Appendix E – new appendix summarising all soil sampling results

• Appendix F – new appendix summarising the key updates to the Contamination DWP during each annual review.

Updates have been made to the following sections:

• Update to sections references throughout given movement of previous Section 4 to new Section 3.4 (refer below)

• Section 2.1 – change to programmed Project completion date

Date

November 2017

September 2018

• Section 2.2 – removal of reference to trucks and trailers for transport of spoil. Site constraints mean that 6W trucks are the only viable option.

• Section 3.3.2 – update to sampling undertaken since the last DWP review

• Section 4 – moved to Section 3.4. Approach summarised and new data presented and discussed

• Sections 4.1 and 4.2 – minor editorial changes

• Sections 4.4.1 and 4.4.2 – Disposal options updated with results of additional investigation

• Section 6.6.3 added exception to water bottles in the excavation area to allow for the requirement for site staff to be readily hydrated

• Section 7.1 – New Zealand Guidelines for Assessing and Managing Asbestos in Soil added to regulations

• Various sections to change reference from Auckland Transport to City Rail Link Limited where appropriate.