Karangahape Station Main Works Contamination Delivery Work Plan
CRL-KRD-RME-LKA-PLN-800024
Revision: 000 Date: January 2020
Page 1
| Karangahape Station Main Works
Contamination Delivery Work Plan
Karangahape Station Main Works - Contamination Delivery Work Plan CRL-KRD-RME-LKA-PLN-800024
This document is uncontrolled when printed. This document should be printed in colour
Revision Status Revision
Date
Version details
Prepared By
Approved By
Rev A01
12/12/2019
Draft for Auckland Council and Independent Peer Review
Elyse Laface
Peter Roan
Rev 000
13/01/2019
Final for submission
Elyse LaFace
Peter Roan
Approval Status Name/Title
Signature
Date
Prepared by:
Elyse LaFace Senior Environmental Specialist
29/01/2020
Reviewed by:
Lean Phuah Senior Contaminated Land Specialist
29/01/2020
Approved by:
Peter Roan Link Alliance – Consents Lead
29/01/2020
Page 2
| Karangahape Station Main Works
Contamination Delivery Work Plan
Table of contents 1. Introduction ............................................................................................. 6 1.1
Karangahape Station ..................................................................................................... 6
1.2
CDWP Staging ............................................................................................................... 7
1.3
Purpose of the CDWP .................................................................................................... 7
1.4
Relevant Conditions ...................................................................................................... 7
1.5
Sustainability .............................................................................................................. 13
1.6
CDWP Review and updates .......................................................................................... 13
1.7
CDWP Author .............................................................................................................. 13
2. Karangahape Main Works ...................................................................... 14 2.1
Overview of Works ...................................................................................................... 14
2.2
Key Personnel ............................................................................................................. 14
3. Summary of contamination assessment ................................................. 16 3.1
Overview .................................................................................................................... 16
3.2
Geology and hydrogeology .......................................................................................... 16
3.3
Soil quality .................................................................................................................. 17
3.4
Groundwater quality ................................................................................................... 17
4. Contamination management ................................................................. 19 4.1
Overview .................................................................................................................... 19
4.2
Excavation of contaminated soil .................................................................................. 19
4.3
Soil material classification ........................................................................................... 19
4.4
Spoil disposal .............................................................................................................. 20
4.5
Transportation of soil .................................................................................................. 21
4.6
Water management .................................................................................................... 21
4.7
Dust Management....................................................................................................... 21
4.8
Odour management .................................................................................................... 22
4.9
Sampling and testing ................................................................................................... 22
4.10 Imported material requirements ................................................................................. 23 4.11 Sealing excavation service trenches ............................................................................. 23
5. Health and safety contamination procedures......................................... 25
Page 3
5.1
Overview .................................................................................................................... 25
5.2
General safety requirements and training .................................................................... 25
5.3
Control measures ........................................................................................................ 26
| Karangahape Station Main Works
Contamination Delivery Work Plan 5.4
Identification of hazards .............................................................................................. 26
5.5
Identification of new hazards ...................................................................................... 26
5.6
Hazard mitigation procedures ...................................................................................... 27
5.6.1.
Dust inhalation .............................................................................................................. 27
5.6.2.
Vapour and gas inhalation ............................................................................................ 27
5.6.3.
Dermal contact and ingestion ....................................................................................... 27
5.7
Personal protective equipment.................................................................................... 28
5.8
Communication plan ................................................................................................... 28
5.9
Incident reporting ....................................................................................................... 28
6. Contingency measures ........................................................................... 29 6.1
Unexpected discovery of contamination ...................................................................... 29
6.1.1. 6.2
Additional requirements for asbestos contaminated soils ........................................... 30
Water discharges ........................................................................................................ 31
7. Works summary/validation reporting .................................................... 33 Appendix A: Review Process - Summary of Outcome ................................... 34 Appendix B: ISCA Requirements................................................................... 36
Page 4
| Karangahape Station Main Works
Contamination Delivery Work Plan
Abbreviations Acronym
Meaning
ACM
Asbestos-containing material
ACoP
Approved Code of Practice: Management and Removal of Asbestos (WorkSafe New Zealand, September 2016).
AF/FA
Asbestos fines/Friable asbestos
ANZECC Guidelines
Australian and New Zealand Environment Conservation Council Guidelines for Fresh and Marine Water Quality (2000)
AUP
Auckland Unitary Plan – Operative in Part
bgl
Below ground level
CCP
Communications and Consultation Plan
CDWP
Contamination Delivery Work Plan
CEMP
Construction Environmental Management Plan
CLS
Contaminated Land Specialist (also referred to as a Contaminated Land Professional).
CRL
City Rail Link
CSA
Construction Support Area
ECBF
East Coast Bays Formation
ESCP
Erosion and Sediment Control Plan
ESM
Environmental and Sustainability Manager
FTMP
Flocculation Treatment Management Plan
HSO
Health and Safety Officer
IS Rating
Infrastructure Sustainability Rating
ISCA
Infrastructure Sustainability Council of Australia
MfE
Ministry for the Environment
NAL
North Auckland Line
NES Soil
Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011
PAH
Polycyclic aromatic hydrocarbons
PPE
Personal protective equipment
SCS
Soil contaminant standards
SQEP
Suitably qualified and experience practitioner; in this context as defined in the NES Soil
SVR
Site Validation Report
TPH
Total petroleum hydrocarbons
WDQMP
Water Discharge Quality Monitoring Programme
Page 5
| Karangahape Station Main Works
Contamination Delivery Work Plan
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 (NAL) in the vicinity of Mt Eden Station. The CRL also involves the construction of two new underground stations at Aotea and Karangahape and a redeveloped station at Mt Eden (refer to Figure 1-1). The design and construction of the CRL infrastructure between the Aotea and Mt Eden Stations is being delivered by the Link Alliance.
Figure 1-1: CRL Route and Location
This Contamination Delivery Work Plan (CDWP) has been prepared in relation to the main construction works for the new Karangahape Station.
1.1 Karangahape Station The Karangahape Station consists of two entrances, one at Beresford Square / Pitt Street and the other at Mercury Lane, linked together by platforms with two mined tunnels approximately 32m below Pitt Street. The Station will also comprise equipment rooms, ventilation systems and emergency egress at both Mercury Lane and Beresford Square / Pitt Street. Given the nature and scale of the Karangahape Station construction, works will be undertaken in a staged manner, involving: • • •
Page 6
Early works (demolition, network utility relocation and site establishment works) – to be undertaken from October 2019 through to early 2020; Main construction works (construction of the station and mined tunnels for the rail tracks) – to be undertaken from early 2020 through to later 2023; and Public realm reinstatement – likely to be undertaken from late 2022 to late 2024.
| Karangahape Station Main Works
Contamination Delivery Work Plan
1.2 CDWP Staging To reflect the staged construction approach for the Karangahape Station, a series of CDWPs are being prepared. This CDWP addresses the Karangahape Station main works, which are detailed in the Construction Environmental Management Plan (CEMP) and summarised in Section 2 of this CDWP. If required, a CDWP will also be prepared in the future to address the station superstructure and public realm reinstatement works.
1.3 Purpose of the CDWP This CDWP has been prepared to identify measures that will be implemented to mitigate and manage the potential adverse effects relating to contaminated land during the construction of Karangahape Station. The objective of the DWP is: •
To avoid, remedy or mitigate the adverse effects of the construction on human health, which may result from the disturbance of contaminated materials during construction; and
•
To minimise discharges to land or water from contaminated soils from within the footprint of the Karangahape Station. The CRL designation (conditions 57 and 58) requires the preparation of a CDWP while conditions 131-150 of the discharge permit (R/REG/2016/1895) and land use consent (R/LUC/2016/1890) require a Contaminated Soils Management Plan. These two separate document requirements have been combined and are addressed in this single CDWP. This CDWP has been prepared in consultation with the Karangahape Community and Business Liaison Group (CLG) and reviewed by the Independent Peer Reviewer (IPR) prior to submission to Auckland Council (as per designation conditions 7 and 11, and resource consent condition 19). A record of consultation outcomes (CLG and IPR) is included in Appendix A. This CDWP has been prepared in general accordance with Ministry for the Environment (MfE) Contaminated Land Management Guideline No. 1: Reporting on Contaminated Sites in New Zealand (revised 2011), and forms part of the CEMP for the Karangahape Station main works.
1.4
Relevant Conditions
Table 1-1 below identifies the designation and resource consent conditions relevant to this CDWP and where they are addressed in the document.
Page 7
| Karangahape Station Main Works
Contamination Delivery Work Plan Table 1-1: Contamination-related conditions and location in Plan
Condition No.
Condition
Relevant section of DWP CRL Designation Conditions
57.1
A Contamination DWP shall be prepared to manage the adverse effects relating to contaminated land during the construction of the City Rail Link or any part of it.
This CDWP
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 CDWP
57.3
To achieve the above objective the following shall be included in the Contamination DWP and implemented as required: a
Page 8
Health and safety plan that addresses: (i)
Worker safety in relation to hazardous substances; and
(ii)
Worker training with regard to handling hazardous substances, identifying potentially contaminated soil/material, and notification procedures for discovery of contamination;
Section 5
b
Procedures for how erosion and sediment control, storm water, dust, and odour control measures will manage the removal of contaminated soil/material;
Section 4
c
Procedures for contaminated soil classification, management and disposal of contaminated soil/material;
Section 4.3and 4.4
d
Where any trenches/excavations during civil works are to be sealed as a result of contamination and how this is to be recorded;
Section 4.11
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 5.2 and 5.6.2
f
Procedures for the monitoring and management of the removal of contaminated soil/material by a suitably qualified environmental specialist;
Sections 4.1-4.5
g
How the placement of re-used contaminated soil/material will be recorded and tracked;
Section 4.4
h
Where areas for stockpiling and storing contaminated soil/material will be established on the construction site and the procedures for managing the containment of the contaminated soil / material in these areas;
Section 4.2
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.
Section 5.8
| Karangahape Station Main Works
Contamination Delivery Work Plan
Condition No.
Condition
Relevant section of DWP
58.1
At the completion of construction works a validation report will be prepared in accordance with any Ministry for the Environment guidelines and submitted to the Auckland Council Consent Monitoring officer documenting the management of soil and evidence of appropriate disposal. The validation report shall include a record of all analytical results, volumes, tip dockets, and any incidents or complaints and how these were addressed. The validation report shall also identify any areas which need on-going monitoring and management by the Requiring Authority.
Section 7
Resource consent conditions 131
At least 20 days prior to the commencement of construction (earthworks), the Consent Holder shall provide a Contaminated Soils Management Plan (CSMP) to the Council (Team Leader Central Monitoring) for certification. The CSMP shall be prepared by a Contaminated Land Professional in accordance with the Contaminated Land Management Guidelines, No.1 Reporting on Contaminated Sites in New Zealand, Ministry for the Environment (revised 2011).
This CDWP
132
The Consent Holder shall request that Council (Team Leader Central Monitoring) provide a determination to the Consent Holder, in writing, within 10 working days of receipt of the CSMP, whether the CSMP can be certified as per the requirements of the Condition 134.
Noted
133
No earthworks shall commence until:
134
a
Certification is provided from the Council (Team Leader Central Monitoring) that the CSMP satisfactorily meets the requirements of Schedule 13 (A4) of the ACRP:ALW, and
Noted
b
All measures identified in that plan as being required to be established prior to the commencement of earthworks have been established.
Section 4.1
The CSMP shall address the following matters: a
The areas within the project site designated for the excavation works, including depths and extent of the proposed works, and an updated map showing the land disturbance activity areas;
Section 2
b
Excavation, management, and disposal procedures for soil, sediment, dust, surface run-off water, perched groundwater, and groundwater, if encountered;
Section 4
c
Temporary containment, treatment, and testing procedures for any water getting in contact with the contaminated material if the disposal option is to the stormwater system or the marine environment is considered;
Section 4.6
d
Contingency measures for unexpected discovery of contamination;
Section 6
e
Proposed sampling and analysis, if applicable; and
Section 4.9
f
Any proposed works summary reporting.
Section 7
Advice Note: The Council acknowledges that the CSMP is intended to provide flexibility for the management of the works and contaminant discharge. Accordingly, the Plan may need to be further updated. Any updates must be limited to the scope of this consent and consistent with the conditions of this consent.
Page 9
| Karangahape Station Main Works
Section 1.6
Contamination Delivery Work Plan
Condition No.
Condition
Relevant section of DWP
135
The Consent Holder shall notify the Council (Team Leader Central Monitoring) at least two working days prior to any earthworks activity on the site and provide the following details:
Section 4.1
a
Name and telephone number of the project manager and the site owner;
b
Site address to which the consents relate;
c
Activity to which the consents relate; and
d
Expected duration of the works.
136
All disturbance of contaminated and potentially contaminated soil shall be carried out in accordance with the certified CSMP required by Condition 131 and any changes to the plan shall be submitted to the Council (Team Leader Central Monitoring) for certification prior to the change being implemented.
This CDWP and Section 1.6
137
The Consent Holder shall ensure that all disturbance of contaminated soil shall be supervised by a suitably qualified and experienced Contaminated Land Professional, whose responsibilities shall include making sure that the soil management and disposal procedures, the contingency measures outlined in the certified CSMP required by Condition 131, and all relevant consent conditions are adhered to.
Section 4.1
138
The Consent Holder shall ensure that regular inspections of the works area shall be carried out by a suitably qualified and experienced Contaminated Land Professional. These inspections shall be documented and the relevant records retained and provided to Council (Team Leader Central Monitoring) in the Site Validation Report (SVR) required by Condition 149.
Section 4.1 and Section 7
139
The Consent Holder shall manage all soil disturbance works to minimise any discharge of debris, soil, silt, sediment or sediment-laden water from the subject site to either land, stormwater systems or the receiving marine environment. The implementation of erosion and sediment controls shall be in accordance with the ESCP required by Condition 53.
Section 4
Advice Note: Measures such as covering the excavations overnight and during heavy rainfall, diverting overland flow around the works area, and appropriate treatment of any water collected in an excavation prior to the disposal may be required to comply with this condition.
140
The Consent Holder shall manage all soil disturbance works to avoid the potential for cross-contamination of materials to occur, in particular, movement of contaminated soil around the site and/or deposition of contaminated soil on other parts of the site shall be avoided. Where soils are identified for off-site disposal, they shall be loaded directly for removal, where possible, and all material shall be covered during transportation off site.
Section 4.2-4.5
141
To minimise the spread of contaminated material, any temporary stockpiles of the excavated contaminated material shall be located within the catchment of erosion and sediment controls for the site. All stockpiles shall be covered with either polythene or an equivalent impermeable material when the site is not being worked and during periods of heavy rain.
Section 4.2
Page 10
| Karangahape Station Main Works
Contamination Delivery Work Plan
Condition No.
Condition
Relevant section of DWP
142
At all times, dust shall be controlled in accordance with the publication titled Good Practice Guide for Assessing and Managing the Environmental Effects of Dust Emissions, Ministry for the Environment (2001).
Section 4.7and the Air Quality Management Plan prepared for the Karangahape Station main works.
143
Excess soil or waste materials removed from the subject site shall be deposited at a disposal site which holds a consent to accept the relevant level or type of contamination.
Section 4.4
Advice note: Where it can be demonstrated that the soil has been fully characterised and meets the definition of ‘clean fill’ material in Section J1 of the Auckland Unitary Plan (Operative in Part), the removal of such material to a consented disposal facility is not required. In such circumstances, a record of the location, depth, and volume of the material removed as ‘clean fill’ should be kept for the purpose of being included in the SVR required by Condition 149).
144
The Consent Holder shall implement the procedures for the management, treatment, temporary containment, testing, and disposal of groundwater and surface run-off water via the stormwater system in accordance with the report titled Auckland City Rail Link: Resource Consent Package 2: Aotea Station to North Auckland Line Construction and CRL Operation: Draft Erosion & Sediment Control Management Plan, dated 13 May 2016, prepared by Aurecon New Zealand Limited, and provided with the application.
Updated Erosion and Sediment Control Plan (ESCP) has been prepared for the Karangahape Station main works.
145
Any perched groundwater, or surface run-off water, encountered within the excavation area requiring removal shall be considered as potentially contaminated, and shall either:
Section 4.6 and Water Discharge Quality Monitoring Programme (WDQMP) included within the Flocculation Treatment Management Plan (FTMP) prepared for the Karangahape Station main works.
146
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, and is free from petroleum hydrocarbons.
Where contaminants which have not been anticipated by the application are identified, works in the area containing the unexpected contamination shall cease until the contingency measures outlined in the certified CSMP required by Condition 131 have been implemented, and have been notified to the Council (Team Leader Central Monitoring). Any unexpected contamination encountered during the works and contingency measures implemented shall be documented in the Site Validation Report required by Condition 149. Advice Note: In accordance with Condition 146, any unexpected contamination may include separate phase hydrocarbons, contaminated soil, perched water or groundwater. The Consent Holder is advised that where unexpected contamination is significantly different in extent and concentration from that
Page 11
| Karangahape Station Main Works
Section 6
Contamination Delivery Work Plan
Condition No.
Condition
Relevant section of DWP
anticipated, handling the contamination may be outside the scope of this consent. Advice should be sought from the Council (Team Leader Central Monitoring) prior to carrying out any further work in the area of the unexpected contamination to check this is within the scope of this consent.
147
All imported fill shall: a
Comply with the definition of clean fill material in Section J1 of the Auckland Unitary Plan (Operative in Part); and
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.
Section 4.10
Advice Note: Background contamination levels for the site receiving clean fill can be found in Technical Publication No. 153, Background concentrations of inorganic elements in soils from the Auckland Region, Auckland Regional Council (2001).
148
All sampling and testing of contamination on the site shall be overseen by a suitably qualified and experienced Contaminated Land Professional. All sampling shall be undertaken in accordance with Contaminated Land Management Guidelines, No.5 – Site Investigation and Analysis of Soils, Ministry for the Environment (revised 2011).
Section 4.9
Advice Note: All testing and analysis should be undertaken in a laboratory with suitable experience and ability to carry out the analysis. For more details on how to confirm the suitability of the laboratory please refer to Contaminated Land Management Guidelines, No.5 – Part 4: Laboratory Analysis, Ministry for the Environment (revised 2011).
149
Within three months of the completion of earthworks on the site, the Consent Holder shall provide a Site Validation Report (SVR) to the Council (Team Leader Central Monitoring). The SVR shall be prepared by a suitably qualified and experienced Contaminated Land Professional in accordance with the Contaminated Land Management Guidelines, No.1 - Reporting on Contaminated Sites in New Zealand, Ministry for the Environment (revised 2011).
Section 7
150
The SVR required by Condition 149 shall address the following matters:
Section 7
Page 12
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 131;
b
The location and dimensions of the excavations carried out, including the relevant site plan;
c
A summary of soil, groundwater, and surface run-off water testing undertaken, if applicable, including tabulated analytical results, and interpretation of the results in the context of the Contaminated Land Rules of the Auckland Unitary Plan (Operative in Part);
d
Copies of the disposal dockets for the contaminated soil and ‘clean fill’ material removed from the site;
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 131 and the conditions of this consent;
g
Results of testing, if required, of any spoil disposed offsite; and
| Karangahape Station Main Works
Contamination Delivery Work Plan
Condition No.
Condition h
1.5
Relevant section of DWP
Results of testing of any imported fill material to ensure compliance with the definition of clean fill material in Section J1 of the Auckland Unitary Plan (Operative in Part).
Sustainability
The Link Alliance is seeking an Infrastructure Sustainability Council of Australia (ISCA) Infrastructure Sustainability (IS) Rating. Further details can be found in the CEMP and Sustainability Rating Management Plan. Project sustainability requirements that relate directly to this CDWP are included in Appendix B. These requirements are imbedded within the Delivery Work Plans and management plans for the project to ensure that sustainability is a key focus and ‘the way we do things’. In some cases, the IS requirements and sustainability goals enhance the designation and consent requirements.
1.6
CDWP Review and updates
This CDWP is a live document that will be reviewed at least annually, or as a result of a material change to the project, or to address unforeseen adverse effects relating to contaminated land arising from construction, or unresolved complaints. Refer to the CEMP for further detail on the review and updating process.
1.7
CDWP Author
This CDWP has been prepared and reviewed by Contaminated Land Specialists (CLS). Elyse LaFace is a Senior Environmental Scientist at Tonkin & Taylor Ltd (T+T) and is the author of this CDWP. Elyse has a Master of Environmental Management, Bachelor of Science with Honours degree in Biology and Geology and a Diploma in Engineering (Civil). She has more than 10 years’ professional experience in the environmental practice area. Lean Phuah is the Discipline Director - Science at T+T and has reviewed this CDWP. Lean has a Bachelor of Civil Engineering degree from the University of Canterbury and is a chartered professional engineer (CPEng) working in the environmental practice area and certified environmental practitioner (CENVP(SC)). She has more than 20 years’ experience in investigations, assessment, management and reporting of contaminated sites. Elyse and Lean are suitably qualified and experienced practitioners (SQEP) under the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (NES Soil).
Page 13
| Karangahape Station Main Works
Contamination Delivery Work Plan
2.
Karangahape Main Works 2.1 Overview of Works
The Karangahape Station main works are described in detail in the CEMP and summarised in Table 2-1 below. It should be noted that construction of the Mercury Lane and Beresford Square station entrance superstructures and other building units, along with the internal station fit out and public realm reinstatement works will form part of separate CDWPs to be prepared in the future prior to the commencement of the respective works. Table 2-1: Overview of Main Works Construction Activities
Works Location
Overview of construction activities
General establishment works
• Installation of hoardings and temporary traffic management around active construction zones
Mercury Lane
• Construction of the temporary shaft at Mercury Lane to provide access for tunnel construction. Works will include excavation, piling and construction of the above ground acoustic enclosure surrounding the shaft. • Mining of platform tunnels (likely using a road header) from the temporary shaft through to the Beresford Square station box. • Diaphragm wall construction and piling around the perimeter of the Mercury Lane station box. • Construction of the Mercury Lane station box, involving: top down construction works - excavation and floor slab construction; and bottom up construction works - rock breaking and excavation, construction of floor slab construction and rail platforms. • Off-site disposal of excavated material from the temporary shaft construction, mining of platform tunnels and station box construction.
Beresford Square
• Diaphragm wall construction and piling around the perimeter of the Beresford Square station box. • Construction of the Beresford Square station box, involving: top down construction works - excavation and floor slab construction; and bottom up construction works - rock breaking and excavation, construction of floor slab construction and rail platforms. • Off-site disposal of excavated material from the station box construction.
Construction Support Areas
• Continued establishment of Construction Support Areas (CSA) at Beresford Square and Mercury Lane (following on from the establishment works undertaken as part of the early works and authorised by the early works plans). This will include the bentonite plant, water treatment plant and temporary spoil storage areas. • Operation of the Beresford Square and Mercury Lane CSAs.
2.2 Key Personnel The key personnel responsible for implementation of this CDWP are identified in Table 2-2. However, all site personnel are responsible for following the requirements of the CDWP. Refer to the CEMP for further detail on roles and responsibilities. Page 14
| Karangahape Station Main Works
Contamination Delivery Work Plan Table 2-2: Key Personnel and Contact details
Role
Name
Karangahape Station Project Manager
Jonathan Hill
Karangahape Station Construction Manager
Dan Trotman
Environmental and Sustainability Manager (ESM)
Sarah Sutherland
Link Alliance Karangahape Main Works Contaminated Land Specialist (CLS)
Elyse LaFace
Link Alliance Communication and Engagement Manager
Rachel Blundell
Page 15
| Karangahape Station Main Works
Contamination Delivery Work Plan
3.
Summary of contamination assessment 3.1 Overview
Contamination investigations conducted to support obtaining the necessary planning approvals for the CRL works in the Karangahape Station area are documented in the following reports: • • •
City Rail Link: Contaminated Land Assessment July 2012, prepared by AECOM; Auckland City Rail Link: Aotea Station to North Auckland Line Construction and CRL Operation Contaminated Land Assessment May 2016, prepared by Golder Associates; and Auckland City Rail Link: Aotea Station to North Auckland Line Construction and CRL Operation Water Quality Assessment May 2016, prepared by Golder Associates.
The contaminated land assessments undertaken in the Karangahape Station area comprised an assessment of soil and groundwater. For accessibility and logistical reasons, the soil and groundwater investigations did not necessarily target specific locations but were positioned to provide an overview of potential ground contamination constraints.
3.2 Geology and hydrogeology A summary of the available geological information indicates the general vertical stratigraphic sequence in the area comprises the following: •
• •
Fill - generally varying in thickness between 2 - 3 m along the Beresford Square and Mercury Lane construction areas, but increases up to 4 m thick just south of the ridge crest at Karangahape Road and 5 - 6 m thick towards the lower slopes and towards Central Motorway Junction; Tauranga Group - local alluvium deposits infill the heads of paleo-tributary gullies south of the ridge crest; East Coast Bays Formation (ECBF) - the thickness of the weathered and residual ECBF varies in the area. The residual ECBF underlies the fill (where no alluvium deposits are present), ranging from 4 - 8 m and 3 - 6 m along Beresford Square and Mercury Lane respectively. The thicknesses of the weathered ECBF vary similarly, before grading into unweathered ECBF at depths between 46 and 54 m RL.
Hydrogeological studies and historic groundwater monitoring data from piezometers installed in the region of Beresford Square and Mercury Lane indicates the presence of a shallow or perched groundwater level, varying between approximately 2 m below ground level (bgl) to 6 m bgl. The perched water level fluctuates between these maximum and minimum levels in response to rainfall events, particularly in the Beresford Square area. Beneath the perched groundwater zone (at depths varying between approximately 8 to 10 m bgl), seasonally permanent saturation of the fill/alluvium/residual ECBF is assumed to occur, representing the top of the regional groundwater system in this area. This regional hydrogeological regime is relatively complex, with up to four regional groundwater levels conceptualised in the hydrogeological model of the area. Further details on the geology and hydrogeology are provided in the ‘Groundwater and Settlement Monitoring and Contingency Plan’ prepared for the Karangahape Station main works.
Page 16
| Karangahape Station Main Works
Contamination Delivery Work Plan
3.3 Soil quality The intrusive investigation work has been undertaken on public land and within road reserves around the CRL project alignment and has not specifically assessed potential contamination on private properties. The investigations identified that significant soil contamination was unlikely to be encountered during land disturbance activities. Soil quality testing undertaken in and around the Karangahape Station is limited and has largely focused on potential contaminants of interest likely to be associated with the urban land use. Soil analysis comprised the following common contaminants considered appropriate for fill with unknown origin and road infrastructure: •
Asbestos;
•
Metals;
•
Polycyclic aromatic hydrocarbons (PAH); and/or
• Total petroleum hydrocarbons (TPH). No olfactory indications for contamination were reported within fill; however, car parts, brick, metal and glass were observed in fill at borehole EB312 (corner of Mercury Lane and Canada Street) between 0.1m and 2.74 m bgl. The NES Soil regulations provide a set of chemical specific soil contaminant thresholds that define an adequate level of protection for human health for a range of differing land-uses in New Zealand (referred to as soil contaminant standards or SCS). For the Karangahape Station works, the NES SCS for commercial/industrial land use has been adopted. All results complied with the adopted NES SCS. Nickel and zinc concentrations in several samples exceeded the Auckland Council criteria for discharges to the environment (previous and current adopted criteria). Cadmium, chromium, copper, lead, zinc and PAH concentrations within fill material also exceeded the published background concentrations for non-volcanic soils in Auckland as described in the Auckland Regional Council Technical Publication 153 – Background Concentrations of Inorganic Elements in Soils from the Auckland Region (TP153). Asbestos is likely present in the underground services due to the age of the utility network. Asbestos in soils was tested for in one sample within the Karangahape Station work areas (BH134 at 0.1-0.2m bgl located towards the north-east end of Beresford Square) with laboratory results reporting asbestos not detected within the sample. Fill material will be removed during the works and will require appropriate disposal (refer Section 4.4).
3.4 Groundwater quality Groundwater information is available for a number of locations on public land and within road reserves along the CRL project alignment. Available groundwater results in and around the Karangahape Station works area were compared to the 95% trigger values of the Australian and New Zealand Environment Conservation Council Guidelines for Fresh and Marine Water Quality (ANZECC Guidelines, 2000). Marine trigger values have been used for comparison for the northern part of the catchment draining to the Waitemata Harbour and freshwater trigger values for the catchment draining west to Motions Creek, with result findings summarised as follows: •
Page 17
Except for boron and copper concentrations within a shallow well in Mercury Lane (BH312), the dissolved trace element data groundwater quality in and around the Karangahape Station was generally lower than the relevant ANZECC Guidelines 95% trigger values; and | Karangahape Station Main Works
Contamination Delivery Work Plan •
Results of total concentrations for arsenic, boron, cadmium, chromium, copper, lead nickel and zinc exceeded ANZECC Guidelines 95% trigger values. These concentrations are considered attributable to very high concentrations of suspended solids present in groundwater samples.
Groundwater will be encountered during the Karangahape Station main works. Site water (surface and groundwater) during construction requiring discharge will be managed through a water quality monitoring programme to ensure discharge quality is met prior to disposal (refer Section 4.6 and the ESCP prepared for the Karangahape Station main works).
Page 18
| Karangahape Station Main Works
Contamination Delivery Work Plan
4.
Contamination management 4.1 Overview
This section details the procedures for the management of contaminated media (soil, groundwater and surface water) during the Karangahape Station main works. It includes control measures for reducing human exposure to contaminated soils and water and minimising contaminated discharges to air, land and/or water. These measures must be established prior to commencing and during earthworks associated with the main works. The Council (Team Leader Central Monitoring) is to be notified at least two working days prior to any of the earthworks. The CLS will observe works associated with disturbance of contaminated soil as appropriate and verify whether the construction team is following procedures. The CLS will document the inspections, with a summary to be included within a works completion report to be prepared and provided to Auckland Council (refer Section 7).
4.2 Excavation of contaminated soil While the protocols below can be applied to all earthworks associated with the Karangahape Station main works, contamination is anticipated to be confined to the fill material. Therefore, the following is most relevant to disturbance within fill: • •
•
•
Erosion and sediment controls shall be implemented in accordance with the ESCP prepared for the Karangahape Station main works before earthworks commence; Excavated soil shall be placed directly into a truck for immediate off-site disposal, where practicable. Excavated soil retained on site as part of contingency storage shall be placed in a designated area, appropriately bunded and covered when not being worked and as weather conditions dictate so as to minimise dust and stormwater runoff; Spillages of soil during placement in trucks shall be cleaned up as soon as practicable following the spillage. Spillages shall not be left unattended as contaminated soil could be trafficked by trucks and transported off-site; and The earthworks shall be observed by the CLS. If unexpected contamination is encountered during works, the works shall cease in the immediate vicinity and the procedures documented in Section 6 of this CDWP shall be followed.
4.3 Soil material classification The spoil generated as result of the Karangahape Station main works will require off-site disposal. In the context of this CDWP, spoil generated shall be classified as per the following three categories to define disposal requirements: Cleanfill Cleanfill material is defined in the Auckland Unitary Plan – Operative in Part (AUP) as: Means natural material such as clay, gravel, sand, soil and rock which has been excavated or quarried from areas that are not contaminated with manufactured chemicals or chemical residues as a result of industrial, commercial, mining or agricultural activities. Excludes: Page 19
| Karangahape Station Main Works
Contamination Delivery Work Plan • • • • • • • •
Hazardous substances and material (such as municipal solid waste) likely to create leachate by means of biological breakdown; Product and materials derived from hazardous waste treatment, stabilisation and disposal practices; Materials such as medical and veterinary waste, asbestos, and radioactive substances; Soil and fill material which contain any trace element specified in Table E30.6.1.4.2 at concentration greater than the background concentration in Auckland soils specified; Sulfidic ores and soils; Combustible components; More than 5 % by volume of inert manufactured materials (e.g. concrete, brick, titles); and More than 2 % by volume of attached biodegradeable material (e.g. vegetation).
Managed fill Managed fill comprises: • • •
•
Soil containing metal contaminants above the published background concentrations in the Auckland region; Soil containing low level hydrocarbon compounds; Soil containing low level asbestos in soil concentrations depending on disposal facility (note: there are no managed fill tip sites within the Auckland Region that can accept asbestos); and/or Soil that does not contain hazardous substances or materials in the form of household and industrial waste or organic waste.
Contaminated fill Contaminated fill comprises: • • •
Soil with concentrations of contaminants exceeding managed fill acceptance criteria; Household and industrial waste; and/or Asbestos in soil and/or asbestos-containing material (ACM).
4.4 Spoil disposal Surplus spoil requiring offsite disposal shall be managed according to the location and nature of the material, as follows: Fill materials • • •
Fill is present across the site varying in depth but typically present between 2 m and 6 m bgl; Based on the available results, fill materials will require disposal as either managed or licenced landfill; and Trucks taking soil for disposal offsite must be lined/ wrapped if required by the receiving managed fill facility and trucks must be covered.
Natural materials • • Page 20
Following removal of fill material, the underlying natural material, if free from staining or odour, is suitable for disposal as cleanfill; and The receiving facility may require confirmatory testing, which should be undertaken in accordance with the soil sampling procedures detailed in Section 4.9. | Karangahape Station Main Works
Contamination Delivery Work Plan In all cases, the necessary permits from the disposal site operator shall be obtained to confirm that they can receive the materials prior to any off-site transportation. All weighbridge dockets and/or a summary sheet shall be retained for inclusion in validation reporting at completion of the works (refer to Section 7). There is limited opportunity for reuse of spoil. If spoil is to be re-used the appropriate environmental controls (if any) are to be advised by the CLS. Such controls may include encapsulating the soil.
4.5 Transportation of soil The following measures shall be implemented to prevent soils 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. A wheel wash will be established on site and vehicles that have tracked over exposed soils will be required to exit the works area via the wheel wash; Excess soil shall be removed from vehicles and plant before they leave the works area; and All trucks transporting excavated soil to the selected disposal facility shall be covered to prevent the spillage of soil and dust emissions.
4.6 Water management Separation and diversion of clean stormwater away from areas of ground disturbance is standard practice for any earthworks activity but becomes more important where contaminants are present. To minimise the potential for clean stormwater to encounter contaminated soil the stormwater and sediment controls detailed in the ESCP for the Karangahape Station main works shall be implemented. Site water including surface water that has been in contact with fill material, groundwater and perched water requiring removal is to be managed via the following methods: • •
•
Piped or pumped to a sediment control system or settlement tank(s) before being discharged to the stormwater system; Further treatment (i.e. flocculent additives, pH adjustment) in accordance with the procedures detailed in the Flocculation Treatment Management Plan (FTMP) for the works; and Testing in accordance with the Water Quality Discharge Monitoring Programme (WQDMP) included in the FTMP to confirm compliance with the criteria for discharge to stormwater.
Alternatively, site water shall either be disposed by licensed liquid waste contractor to a licenced facility or discharged to sewer (subject to approval by Watercare Services Limited). For discharges to sewer monitoring shall be conducted in accordance with the applicable permit conditions, e.g. trade waste agreement requirements.
4.7 Dust Management To minimise the generation of dust during earthworks (particularly during earthworks within fill), the following controls shall be implemented:
Page 21
| Karangahape Station Main Works
Contamination Delivery Work Plan •
• • • • • •
Weather forecasts shall be obtained each day during work to check for predicted high wind conditions and any such predictions shall be notified to relevant construction staff so that dust management procedures are adequately prepared and implemented; In windy conditions, if soils are dry and friable during excavation then they shall be dampened with water; Limit drop heights of soil from the excavator bucket into trucks; Immediately clean up spilled soil from truck loading areas prior to loading additional trucks; Ensure vehicles do not leave site with excess soils between the tyre tread as this will be distributed on public roads and will generate dust; If dust cannot be controlled during excessively windy conditions, then earthworks shall cease until dust can be managed; and If a dust release occurs, the time, duration, location and cause is to be recorded in the daily report as well as remedial action performed.
Further dust management and monitoring requirements are set out in the Air Quality Management Plan prepared for the Karangahape Station main works.
4.8 Odour management The contaminants in soil and groundwater, particularly during excavation in the fill, are unlikely to generate odours and vapours. If odorous soil is encountered, then the actions outlined below shall be implemented: • • • •
Limit the timeframe in which odorous materials are exposed and excavation is being undertaken; Install a ducted fan or additional mechanical ventilation to reduce vapour concentrations in the area; Install an odour suppressant system at a suitable location, if appropriate; and If odorous material is encountered, the time, duration, location and cause is to be recorded in the daily report as well as remedial action performed, including notifying the CLS.
Further odour management and monitoring requirements are set out in the Air Quality Management Plan prepared for the Karangahape Station main works.
4.9 Sampling and testing Any sampling and testing of soils shall be undertaken by the CLS according to the requirements of the NES Soil Regulations and the MfE Contaminated Land Management Guidelines No.5. Site Investigation and Sampling (revised 2011). Samples for asbestos testing (if required) shall be collected in accordance with the NZ Asbestos in Soil Guidelines1. Soil samples shall be collected according to the following procedure: •
•
1
The materials encountered shall be described in accordance with the NZ Geotechnical Society Guidelines for the classification and field description of soils and rocks for engineering purposes; Hands shall be freshly gloved to collect soil and the samples shall be placed immediately into the appropriate laboratory supplied sample containers;
BRANZ, 2017, New Zealand Guidelines for Assessing and Managing Asbestos in Soil Page 22 | Karangahape Station Main Works
Contamination Delivery Work Plan • •
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 a 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 CLS shall evaluate any analytical results against the relevant human health and environmental discharge regulatory standards/acceptance criteria as appropriate.
4.10 Imported material requirements It is not anticipated that soil materials will be imported as part of the Karangahape Station main works. In the event that soil materials are imported these shall originate from: •
A site which has been determined by a suitably qualified contaminated land professional to have had no known history of potentially contaminating activities, as detailed on the Ministry for the Environment’s Hazardous Activities and Industries List (HAIL); or
•
A site which has been adequately investigated by a suitably qualified contaminated land professional, in accordance with the MfE Contaminated Land Management Guidelines No. 5 Site Investigation and Analysis of Soils (revised 2011), to meet the ‘cleanfill material’ definition as prescribed in the AUP (refer Section 4.3). Soil materials imported will typically be tested at a rate of 1 in 500 m3 for metals and PAH and any evidence of the presence of asbestos shall trigger testing for asbestos content in soil. The CLS will determine the required rate and analytes based on the source site. It is preferable that the fill is tested at its source prior to its use at the site. However, if not, then the imported soil materials shall be stockpiled on site with appropriate controls until test results are available. Additionally, engineering materials may be used including clean quarry materials and recycled crushed concrete aggregate that is sourced from the site or sourced from a quarry or supplier. The supplier of these materials is to provide documentation to confirm suitability for use. For crushed concrete aggregate the following additional information is required: •
Sourced from the site: address of the source site, copies of pre-demolition asbestos surveys, copies of asbestos clearance certificates prepared prior to demolition and asbestos testing at a rate of 1 in 500 m3.
•
Sourced from a supplier: confirmation of processing procedures and asbestos testing at a rate of 1 in 500 m3 of product is to be provided by the supplier. The CLS shall review the supplied information prior to acceptance or the material stockpiled on site until available.
4.11 Sealing excavation service trenches If contaminated material is encountered and sealing of excavation service trenches is required to prevent them from acting as a conduit for migration of contaminated groundwater away from the site, a pipe dam shall be installed at the boundary of the project footprint. The pipe dam shall be either concrete or another impervious material to be specified by the drainage design engineer. The dam shall encase the pipe and extend up the trench to just below the paved surface as shown in Figure 4-1 below. The locations of pipe dams will be recorded on as-built drainage drawings and included in the validation reporting at completion of the works (refer to Section 7). Page 23
| Karangahape Station Main Works
Contamination Delivery Work Plan
Figure 4-1: Sketch of pipe dam
Page 24
| Karangahape Station Main Works
Contamination Delivery Work Plan
5.
Health and safety contamination procedures 5.1 Overview
This CDWP provides procedures for site personnel working in and around contaminated and/or potentially contaminated soil and water during the excavation works. The following is designed to dovetail with the Construction Health and Safety Management Plan. The procedures have been developed to provide a framework for managing contamination related effects at the site. However, these procedures are not intended to relieve the owner or controller of the place of work of either their responsibility for the health and safety of their workers, contractors and the public, or their responsibility for the protection of the environment. All parties working on the Karangahape Station main works shall comply with: • • • • •
Applicable parts of the Link Alliance Health and Safety Policy; Construction Health and Safety Management Plan; Any requirements of WorkSafe New Zealand; The Health and Safety at Work Act 2016 and Regulations; and Any other applicable legislation, regulations, codes and guidelines.
Sub-contractors engaged on the Karangahape Station main works area are required to provide their own Health and Safety Plan for their equipment and workers. Daily toolbox meetings are to be undertaken and documented.
5.2 General safety requirements and training All relevant personnel shall be required to participate in a site induction that includes a review of procedures with respect to contamination. The induction shall be provided such that all relevant personnel understand, prior to commencing work, what procedures are to be implemented and why. The purpose of the induction is to educate the workers with respect to the hazards associated with contaminated soil and water, safe working procedures, safety equipment and requirements, and the response plan in the event of an emergency. An appropriately qualified Health and Safety Officer (HSO), or similar, shall be appointed for the duration of the works so that where contamination is being managed, there is a designated person responsible for the implementation of and adherence to contamination related health and safety procedures, in addition to the other site specific health and safety requirements. The HSO shall ensure that all relevant personnel are familiar with the application and use of required PPE and procedures specified in this CDWP and other site specific documentation prior to the commencement of work. The following general safety procedures shall be followed by all personnel entering and/or working in the construction zone: • •
Page 25
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;
| Karangahape Station Main Works
Contamination Delivery Work Plan • •
Site personnel shall avoid unnecessary contact with documented and potentially contaminated soil and groundwater; and Site personnel who may come into contact with contaminated soil shall be provided with the minimum level of PPE as defined in Section 5.7 of this CDWP.
5.3 Control measures When considering hazard and risk controls, the hierarchy listed below will be followed, in preference from one to five. Example questions are provided to illustrate each step. 1. 2. 3. 4.
ELIMINATION – does the task that creates the hazard need to be performed? SUBSTITUTION – can a different tool be used? ENGINEERING – can the hazard be guarded to protect people? ADMINISTRATION – are there warning signs and a procedure to address the hazard? Administrative controls include procedures to reduce the risks associated with identified hazards. These controls include: 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.
5.4 Identification of hazards This CDWP identifies potential hazards associated with the presence of soil and groundwater contamination and recommends procedures to mitigate these risks. Contamination investigations indicate low level contamination within fill material and groundwater (refer Section 3). The fill material contamination includes metals/metalloids and hydrocarbons, and groundwater was found to exceed consented discharge criteria for some metals/metalloids. Potential exposure routes for contaminants include: • • • •
Inhalation of dust (potentially contaminated and uncontaminated); Ingestion of potentially contaminated soil, dust or groundwater; Dermal absorption of potentially contaminated soil or dust; and Skin and eye contact with potentially contaminated soil or dust.
Recommended procedures to mitigate the risk associated with these hazards are provided in Section 5.6.
5.5 Identification of new hazards There is the potential for additional hazards to be identified and encountered during the Karangahape Station main works. The HSO is responsible for reviewing any new work element and assessing whether there are any new associated hazards and associated elimination, isolation and Page 26
| Karangahape Station Main Works
Contamination Delivery Work Plan minimisation measures. The HSO shall seek review by the CLS if necessary. The HSO shall then instruct all personnel on the health and safety procedures associated with the new hazard.
5.6 Hazard mitigation procedures 5.6.1. 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 4.7 of this CDWP. The following additional measures shall be considered to minimise inhalation of dust: • • •
Monitor wind speed and direction, and where practicable, stand up wind of excavations and vehicle loading areas; Water spray via localised points; and Boot wash available for personnel leaving excavation areas to prevent the tracking of soil around and off-site.
Additional controls may be required if asbestos in soils is detected as part of any additional testing or if unexpected contamination is encountered. The controls to be implemented are outlined in Section 6.1.1 and may include the use of a polymer spray in addition to water to manage dust and additional PPE (i.e. disposable coveralls, and respiratory protective equipment).
5.6.2. Vapour and gas inhalation The investigations to date indicate there is a low potential for the presence of volatile contaminants or gases that are likely to represent a human health risk with respect to the inhalation exposure route. However, mitigation of vapour or risk can be achieved as follows: •
•
•
If there are olfactory indications for vapours, or vapours are suspected, the volatile organic compound (VOC) content of the area shall be checked with a calibrated photo-ionisation detector (PID) with a 10.6 electron volt (eV) lamp. If readings are above 50 ppm, work shall stop, the area vacated and the CLS and/or HSO shall be informed. A respirator shall be worn when re-entering the area to re-test the atmosphere; At the same time, and if an area or excavation is to be accessed with limited air flow (i.e. excavations below existing floor slabs) air quality shall be monitored prior to entry using a calibrated gas meter(s) able to measure lower explosive limit (LEL), oxygen (O2), methane (CH4), carbon monoxide (CO) and hydrogen sulphide (H2S); and Work shall not resume unless approved by the HSO in consultation with the CLS.
5.6.3. Dermal contact and ingestion The following precautionary measures shall be implemented to ensure skin contact with, and ingestion of, contaminants is minimised: •
• •
Page 27
Disposable gloves shall be worn by personnel who need to have contact with contaminated soil during the excavation works. Consideration shall be given to the requirement for tear resistant gloves; Overalls shall be worn if there is the potential for contaminated soil to contact other parts of the body (legs, arms etc.); Boot covers shall be worn by personnel who need to traverse contaminated soils during excavation works or washable boots worn with a boot wash in place and utilised; and | Karangahape Station Main Works
Contamination Delivery Work Plan •
There shall be no eating, drinking or smoking in the works area to prevent contaminated soil contacting food or being ingested directly via soiled hands.
A key factor in controlling dermal contact and ingestion of contaminated soil is through maintaining good personal hygiene. The following shall be observed for works involving contaminated soils: • • • • •
Hand to mouth and hand to face contact shall be avoided during work; Hands shall be washed before eating, drinking and smoking; Eating, drinking and smoking shall only be permitted in designated areas; Overalls worn within the works area shall be removed before leaving the works area; and Disposable coveralls may be worn and disposed of at the end of each working day.
5.7 Personal protective equipment All workers handling or coming into contact with contaminated or potentially contaminated soil shall wear the following PPE to protect against the above risks: • •
Overalls or disposable coveralls; and Impermeable gloves (tear resistant if appropriate).
Additional PPE (refer PPE and minimum respiratory protective equipment in Section 6.1.1) may be required if asbestos in soil is detected as part of any additional testing or if unexpected contamination is encountered. Such controls include the use of disposable coveralls (rated type 5, category 3), disposable overshoes (or similar) and specific respiratory protective equipment depending on the type and concentration of asbestos present (as a minimum disposable P2 dust mask shall be available on site). Changes to site specific PPE requirements shall be reflected in all health and safety documentation and all parties notified. The PPE specified above is in addition to that required for non-contamination related health and safety.
5.8 Communication plan Details of communication and consultation procedures are set out within Sections 6.5 and 7 of the Karangahape Main Works Communication and Consultation Plan (CCP). The CCP outlines the way in which the general public are to be communicated with on CRL project matters, including the management of the adverse effects relating to the contamination and the process for public and affected parties to register a complaint.
5.9 Incident reporting Procedures relating to environmental emergencies and incidents are detailed within the CEMP. The CEMP should be referenced for further information on environmental incidents including spill response, incident recording and reporting.
Page 28
| Karangahape Station Main Works
Contamination Delivery Work Plan
6.
Contingency measures 6.1 Unexpected discovery of contamination
If during earthworks, contaminated soils or hazardous material in addition to those described in Section 3.3 is encountered, work in the area of concern shall cease until the CLS has assessed and identified the material. Evidence of additional contamination likely to trigger a stop work procedure may include: • • • • •
Visual (buried refuse, metal objects, building material, soil or water staining/bleaching or discolouration); Chemical odours (fuel, sulphurous, rotting vegetation or sewage); Separate phase liquids or ‘rainbow effect’ films on groundwater; Auditory (gas leaks, flowing or dripping liquid); and Fibrous cement based board materials that may contain asbestos.
If any such indicator is observed during earthworks, the following steps should be taken: • • • • •
• •
• •
Page 29
Cease all work within a 10 m radius and make the work area safe and restrict access to all workers until instructed by the ESM or delegate; Shut off all ignition sources and, if possible, contain any contaminant discharge and close/divert any water flow; Advise the ESM; Work shall not resume until the ‘all clear’ is given by the ESM; The ESM (in consultation with the CLS) shall assess the area. If the assessment concludes that confirmation of contamination is required, the following actions shall be implemented: o Control the site through installation of temporary fencing, temporary cover, silt traps and bunding as required around the area of potential contamination o Small volumes of excavated soil shall be contained in covered skips to minimise contaminated discharges from rainfall runoff and dust o If this is not possible, larger volumes shall be covered and bunded to manage dust and stormwater runoff o Potentially contaminated water shall be collected and disposed of to an appropriately licensed treatment facility. It must not be discharged to the construction stormwater system o Samples of the suspect material shall be collected (by the CLS or delegate) for laboratory analyses using appropriate procedures (refer Section 4.9) The results of the laboratory analysis shall be assessed against the relevant human health and environmental discharge regulatory standards/acceptance criteria as appropriate; The CLS should be consulted on the handling and management of contaminated soil and/or water, and any specific health and safety precautions that may need to be taken to minimise risk to construction workers/and or the general public; Any soils or material requiring off-site disposal must be disposed of at facilities consented to accept the material; and Maintain a register of any additional contaminated material discovered, including location, type, quantity and disposal record (disposal receipts). This information will be documented in the Site Validation Report (refer Section 7). | Karangahape Station Main Works
Contamination Delivery Work Plan •
Where unexpected contamination is significantly different in extent and concentration from that anticipated, the Council (Team Leader Central Monitoring) will be advised prior to carrying out any further work in the area of the unexpected contamination.
6.1.1. Additional requirements for asbestos contaminated soils The management of asbestos in soils is regulated under the Health and Safety at Work (Asbestos) Regulations 2016 (Asbestos Regulations). In order to help achieve compliance with the Asbestos Regulations, WorkSafe New Zealand has prepared an Approved Code of Practice (ACoP): Management and Removal of Asbestos (September 2016). The ACoP refers readers to the NZ Asbestos in Soil Guidelines. The key requirements of the Regulations and ACoP are that works involving asbestos contaminated soils must be undertaken with appropriate asbestos controls in place and that contaminated soil removed from site must be taken to an approved disposal site. Table 6-1 provides a summary of the controls indicated in the NZ Asbestos in Soil Guidelines for different concentrations of asbestos fines/friable asbestos (AF/FA) and ACM. This CDWP is to be reviewed and updated to confirm the controls to be implemented on receipt and review of any additional soil results that indicate the presence of asbestos in soils. Table 6-1: Summary of asbestos requirements as detailed in the NZ Asbestos in Soil Guidelines Scenario
Class A works – nonfriable
Class B works – nonfriable
Asbestos-related works
Unlicensed asbestos work
>0.1% w/w AF+FA in soil
>0.01% w/w AF+FA in soil
>0.001% w/w AF+FA in soil
≤0.001% w/w AF+FA in soil
>1% ACM
>0.01 % w/w ACM
<0.01% w/w ACM
Additional documentation/ notification requirements
Asbestos removal control plan and WorkSafe notification for asbestos removal
Asbestos removal control plan and WorkSafe notification for asbestos removal
No additional notification required
No additional notification required
Oversight by a licensed removalist
Required
Required
Not required
Not required
Personal protective equipment (PPE)
Disposable coveralls rated type 5, category 3, nitrile gloves, steel toe capped gumboots or safety footwear with disposable overshoes.
Disposable coveralls rated type 5, category 3, nitrile gloves, steel toe capped gumboots or safety footwear with disposable overshoes.
Disposable coveralls rated type 5, category 3, nitrile gloves, steel toe capped gumboots or safety footwear with disposable overshoes.
No asbestos-specific PPE as concentrations are unlikely to exceed trace levels in air.
Minimum respiratory protective equipment
Full-face P3 respirator with particulate filter.
Half-face P3 respirator with particulate filter.
Disposable P2 dust mask
No asbestos-specific requirements as concentrations are unlikely to exceed trace levels in air
Dust/asbestos fibre suppression
Water and polymer spray via localised points before and during works.
Water and polymer spray via localised points before and during works.
Water spray via localised points.
Water spray via localised points.
Page 30
| Karangahape Station Main Works
Contamination Delivery Work Plan
Scenario
Class A works – nonfriable
Class B works – nonfriable
Asbestos-related works
Unlicensed asbestos work
>0.1% w/w AF+FA in soil
>0.01% w/w AF+FA in soil
>0.001% w/w AF+FA in soil
≤0.001% w/w AF+FA in soil
>1% ACM
>0.01 % w/w ACM
<0.01% w/w ACM
Air monitoring
Air monitoring required
Air monitoring not required but can be undertaken depending on the site setting and to confirm that concentrations are below 0.01 f/ml
Air monitoring not required but can be undertaken depending on site setting to confirm that concentrations are below 0.01 f/ml
Air monitoring not required
Decontamination facilities
Dedicated wet decontamination area or trailer. Consider powered and plumbed unit
Dedicated decontamination area and foot wash
Dedicated decontamination area and foot wash
Foot wash and used PPE collection area.
Vehicle (truck) protection
200 µm heavy-gauge polythene wrapped soil/lined trays and truck covered. HEPA filter system fitted for all occupied vehicles filter replaced or clean down with HEPA vacuum cleaner post work
200 µm heavy-gauge polythene wrapped soil/lined trays and truck covered. HEPA filter system fitted for all occupied vehicles where friable ACM on site (lagging, insulation, etc).
Truck lining/soil wrapping depends on the receiving landfill. All trucks should be covered. Standard air conditioning.
Truck lining/soil wrapping depends on the receiving landfill. All trucks should be covered. Standard air conditioning.
Vehicle Washing Facilities and Clearance Requirements
No high water pressure spray. Visual assessment plus swab and air sampling inside the cab by an independent assessor
No high water pressure spray. Visual assessment plus swab (if friable) by an independent assessor or independent competent person* or SQEP following brush and or wash down
No high water pressure spray. Visual assessment by a competent person* or SQEP following brush and or wash down
No high water pressure spray. Visual assessment by a competent person* or SQEP following brush and or wash down
Finishing surfacing/cap
No special finishing/cover requirements if soils are confirmed to meet health criterion (0.001% w/w). Otherwise: Hard cap - No depth limitation, no controls. Soft cap – at least 0.2 m and should be delineated by a permeable geotextile marker layers between the cap and underlying asbestos/contaminated material.
Ongoing management
If validation testing shows any soil at the base of any excavation contains asbestos, even at <0.001% w/w, the Asbestos Regulations require the location of these to be recorded in an asbestos management plan.
* A competent person must meet the requirements of regulation 41(3) of the Asbestos Regulations.
6.2 Water discharges As described in Section 4.6, where the quality of water being discharged from the site cannot meet the standards required for discharge to stormwater, or unexpected contamination conditions are encountered (refer to Section 6.1), additional controls will be required.
Page 31
| Karangahape Station Main Works
Contamination Delivery Work Plan If unexpected contamination conditions are encountered, the affected area shall be isolated so that stormwater from this area can be separated from that generated across the wider site. A number of options could be employed if the quality of water being discharged from the site cannot meet the standards required for discharge to stormwater on an ongoing basis, including, but not limited to: • • •
Improving effluent quality through additional treatment; and/or Collection (for example by tanker trucks) for off-site disposal to an appropriately licensed facility; and/or Discharge to sewer, subject to removal of sediment and issue of any necessary temporary trade waste permits.
The CLS shall be consulted to assist with defining appropriate control measures in the event that the standards required for discharge to stormwater cannot be met.
Page 32
| Karangahape Station Main Works
Contamination Delivery Work Plan
7.
Works summary/validation reporting
On completion of the soil disturbance works associated with the Karangahape Station main works, a works completion report (also referred to as a site validation report) will be prepared and provided to Auckland Council. The purpose of the works summary report is to confirm that the objectives of the works have been achieved, and that the works were undertaken according to agreed procedures and reporting on any incidents. The report is required to be prepared by the CLS and shall comply with the MfE Contaminated Land Guideline No. 1 - Guidelines for Reporting on Contaminated Sites in New Zealand (revised 2011). The report shall include, as a minimum: •
• • • • • • • •
A summary of the works undertaken, including a site plan and a statement confirming whether the excavation of the site has been completed in accordance with the certified CDWP; The location and dimensions of the excavations carried out, including relevant site plan and location of contaminated soil reused (if any); Summary of the disposal dockets for the spoil disposed off-site; Summary of the inspections undertaken by the CLS during disturbance of contaminated soil; Records of any unexpected contamination encountered during the works and contingency measures undertaken (if applicable); Details regarding any complaints and/or breaches of the procedures related to contamination; Results of any testing undertaken; Documentation and results of testing of any imported fill; and Any long term monitoring/management requirements.
This report shall be provided to Auckland Council within three months of completion of the soil disturbance works associated with the Karangahape Station main works.
Page 33
| Karangahape Station Main Works
Contamination Delivery Work Plan
Appendix A: Review Process - Summary of Outcome
Page 34
| Karangahape Station Main Works
Contamination Delivery Work Plan
Community Liaison Group (CLG) review outcomes A Karangahape CLG meeting was held on 12 November 2019 to discuss the Karangahape Station main works and for the CLG to provide comments / feedback on the CEMP and sub-plans, including this CDWP. No comments were received from the CLG on this CDWP.
Independent Peer Review (IPR) outcomes The CDWP was reviewed by the Independent Peer Reviewer – Terre Nicholson of HD Geo Limited. Comments received from the Independent Peer Reviewer are documented along with details of resolution are in the following table. Section of this CDWP
Comment
Response
1.7, 3.4, 4.2, 4.4 and 5.6.1
Minor typographical edits for correctness.
Edits made as noted.
Auckland Council comments The CDWP was reviewed by the Marija Jukic, Senior Specialist in Contaminated Land, Auckland Council. Comments received along with details of resolution are in the following table. Section of this CDWP
Comment
Response
1.4: Relevant Conditions
Fix broken hyperlinks.
Hyperlinks updated.
4.10: Imported fill
Sampling rate reduced from proposed.
Updated to reduce the typical sampling rate to 1 sample per 500 m3; to be confirmed by the CLS based on the source site.
Page 35
| Karangahape Station Main Works
Contamination Delivery Work Plan
Appendix B: ISCA Requirements
Page 36
| Karangahape Station Main Works
Contamination Delivery Work Plan
Implementation of ISCA The table below identifies the ISCA Credit Requirements relevant to this CDWP and where they are addressed in the documents. Credit
Relevant Section
Requirements *
Other Relevant Information / Comments
Whenua (Land) Lan-3 Level 1
Site assessment follows the recommended approach in ‘CLMG No.5 Site Investigation and Analysis of Soils’.
Section 3
A site assessments have been completed for the Karangahape Station as part of the wider CRL project.
Lan-3 Level 1
Remediation options are identified and selected using a sustainability hierarchy.
Sections 4.3, 4.4, 4.6 and 6.
Lan-3 Level 2
Sustainability appraisal of remediation options is undertaken against the sustainability indicators in Table 1 of ‘A Framework for Assessing the Sustainability of Soil and Groundwater Remediation’.
Contaminated fill (and underlying natural material) needs to be removed as part of the Karangahape Station main works. Spoil within the Karangahape Station main works area needs to be removed and disposed of offsite to enable this component of the CRL Project to be realised. Due to the urban and constrained nature of the works area there is no location within the CRL Project area for soils to be retained or returned to site. Disposal of soil from the Karangahape Station main works shall be based on the soil classification hierarchy and approval process that is outlined in Sections 4.3 and 4.4 of this C DWP. If unexpected soil contamination is identified, the requirements of Section 6 of this CDWP are to be implemented and soil remediation and management options will be assessed using the ISCA sustainability hierarchy approach as applicable.
Receiving Wai (Water) Quality DIS-1 Level 1
Page 37
Measures to minimise adverse impacts to receiving wai environmental values during construction and operation have been identified and implemented. These measures demonstrate an awareness of the values of wai ora and its Mauri, and opportunity for mana whenua feedback has been provided and where practicable incorporated into these measures. AND
| Karangahape Station Main Works
Section 4.6
A Water Discharge Quality Monitoring Programme (WDQMP) has been developed which specifies the monitoring to be undertaken for the Karangahape Station main works. The WDQMP is included within the FTMP and provides specific requirements on the discharges to the receiving environment.
Contamination Delivery Work Plan
Credit
Requirements *
Relevant Section
Other Relevant Information / Comments
Whenua (Land) Monitoring of wai discharges and receiving wai is undertaken at appropriate intervals and at times of discharge during construction.
ISCA Lan-3 sustainability hierarchy The ISCA Lan-3 sustainability appraisal process includes the following sustainability hierarchy for remediation: 1. If practicable, on site treatment of the contamination so that it is destroyed or the associated risk is reduced to an acceptable level. 2. Off-site treatment of excavated soil, so that the contamination is destroyed or the associated risk is reduced to an acceptable level, after which soil is returned to the site. 3. Consolidation and isolation of the soil on site by containment with a properly designed barrier. 4. Removal of contaminated material 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. If an option less favourable than the first option is selected, then justification for not selecting options higher on the hierarchy must be provided. In cases were no readily available or economically feasible method is available for remediation, it may be possible to adopt appropriate regulatory controls to develop other forms of remediation.
Page 38
| Karangahape Station Main Works