SH20 Manukau Harbour Crossing - Assessment of ... · Note 1 Proposed form of interchange revised...

State Highway 20 Manukau Harbour Crossing ProjectAppendix 19 - Draft Environmental

Management Plan

CER 06/022

State Highway 20 Manukau Harbour Crossing Project

Draft Environmental Management Plan May 2006

Opus International Consultants Limited Auckland Office Level 3, The Westhaven 100 Beaumont Street, PO Box 5848, Wellesley Street Auckland, New Zealand Telephone: +64 9 355 9500 Facsimile: +64 9 355 9585 Date: 19 May 2006 Reference: 1-81074.35AR Status: Final

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NOTE: Report annotated September 2006 to refer to project updates described in August 2006 Section 92 Response Reports. Refer to notes on following page

SH20 Manukau Harbour Crossing Project Annotation Notes

Reference in text

Note

1 Proposed form of interchange revised August 2006 to “quarter diamond” configuration. Refer to August 2006 Interchange Report and s.92 Response Report to Auckland City Council.

2 Temporary reclamations no longer proposed. Coastal Permit application for temporary reclamation at Onehunga Harbour Road withdrawn August 2006.

3 Extent and area of proposed reclamation revised. Refer August 2006 s.92 Response Report to Auckland Regional Council.

4 Coastal Permit applications for replacement of Old Mangere Bridge were lodged in May 2006 but withdrawn in August 2006 to enable further consideration of design options. General information relating to the proposed replacement bridge as described within this AEE remains relevant. New consent applications will be lodged at a later date as appropriate. The concept design for the replacement bridge will be confirmed at that time.

5 The proposed designation no longer includes the Manukau Cruising Club lease area (refer August 2006 s.92 Response Report to Auckland City Council). The building, carparking area and boat ramp are no longer directly affected by the works.

6 Stormwater management proposals revised. Refer August 2006 s.92 Response Report to Auckland Regional Council.

28 September 2006 P.T.O

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SH20 Manukau Harbour Crossing Project Annotation Notes

Background

Transit’s proposals for the Manukau Harbour Crossing Project were submitted to Auckland City Council, Manukau City Council and the Auckland Regional Council in May 2006.

All three Councils requested further information from Transit, and this information was provided in August 2006. The requests for further information were made in accordance with Section 92 of the Resource Management Act 1991.

Preparation of this additional information has resulted in some revisions to the original proposals, and these are reflected in supplementary documentation dated 28 August 2006. The key revisions made are summarised below.

Key Revisions

• The proposed form of the motorway interchange at Gloucester Park has been revised from a “diamond” to a “quarter diamond” configuration.

• The extent of reclamation proposed within the Manukau Harbour has been reduced – only one area of reclamation is now proposed, this being along Onehunga Harbour Road and Orpheus Drive, east of the Manukau Cruising Club.

• The Manukau Cruising Club and associated parking area is no longer affected by the proposed works.

• Coastal Permit applications relating to demolition of the old Mangere Bridge and replacement with a new pedestrian and cycle bridge have been withdrawn to enable further consideration of design options.

• Stormwater management proposals have been refined to offer an improved degree of treatment prior to discharge to the receiving environment.

Notification Documentation

The documents submitted with the consent applications and Notices of Requirement in May 2006, along with the more recent information prepared in response to requests from the Councils for further information are available in full for viewing as part of the public notification process.

To avoid confusion, the May 2006 documentation has been annotated where appropriate to refer to the recent revisions summarised above and described in the August 2006 reports.

Reports Referred to in Annotations – Full Titles

Title Date Status / revision

August 2006 Interchange Report

Report: SH20 Manukau Harbour Crossing Project - Gloucester Park Interchange: Further Consideration of Alternatives

28 August 2006 Rev A Final

s.92 Response Report to Auckland City Council

Report: Response to Auckland City Council Requests for Further Information under Section 92 of the Resource Management Act 1991

28 August 2006 Final

s.92 Response Report to ARC

Report: Response to Auckland Regional Council Request for Further Information under Section 92 of the Resource Management Act 1991

28 August 2006 Final

SH20 Manukau Harbour Crossing Project- Assessment of Environmental Effects Appendix 19 - Draft Environmental Management Plan

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Table of Contents

1 Executive Summary ....................................................................................................8

2 Introduction .................................................................................................................9

2.1 Purpose of Environmental Management Plan.....................................................9 2.2 Plan Status .......................................................................................................10 2.3 Related Documentation ....................................................................................10 2.4 Authority for Administration of This Plan ...........................................................11 2.5 Mechanisms for Revision..................................................................................12

3 Mitigation of Adverse Effects...................................................................................14

3.1 Environmental Objective ...................................................................................14 3.2 Environmental Principles ..................................................................................14 3.3 Environmental Methods ....................................................................................14 3.4 Environmental Management Approach.............................................................14

4 Environmental Management Plan Requirements ...................................................15

4.1 Environmental Monitoring Guidelines ...............................................................15 4.2 Engineer’s Environmental Management Plan ...................................................17 4.3 Contractor’s Environmental Management Plan.................................................19

5 General Requirements ..............................................................................................23

5.1 General Consent Holder Requirements ............................................................24 5.2 General Implementation Requirements ............................................................24 5.3 Archaeological Requirements ...........................................................................26 5.4 Potential Soil Contamination.............................................................................27 5.5 Chemical Treatment Criteria .............................................................................31

6 Activity Specific Requirements................................................................................33

6.1 Erosion and Sediment Control ..........................................................................33 6.2 Permanent Stormwater Management ...............................................................35 6.3 Works Within the CMA......................................................................................38 6.4 Survey...............................................................................................................40 6.5 Site Investigations.............................................................................................41 6.6 Stockpiles .........................................................................................................41 6.7 Refuelling/Maintenance Areas ..........................................................................42 6.8 Site Facilities.....................................................................................................42 6.9 Dust Control ......................................................................................................43 6.10 Dewatering........................................................................................................44 6.11 Sealing..............................................................................................................44 6.12 Installation of Services ......................................................................................45 6.13 Weed Control ....................................................................................................45 6.14 Noise and Vibration...........................................................................................45


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List of Figures Figure 1: Environmental Management Framework Figure 2: Approach for Managing Potential Contaminants During Construction Figure 3: Flocculation Criteria


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Glossary ACC Auckland City Council. Activity Specific Environmental mitigation requirements identified for all activities. Controls undertaken during the course of the Project with the likelihood of

giving rise to adverse environmental effects. AEE Assessment of Environmental Effects. AEP Annual Exceedance Probability. alignment The structural extent of the carriageway. Note the alignment is not

the same as the designation. ANZECC Australian and New Zealand Environment and Conservation

Council. ARC Auckland Regional Council. ARI Average recurrence interval. bed of the stream The high tide channel in intertidal areas or that extent of the

watercourse or streambed or channel that exists within the bankfull conditions.

berm A strip of land of given width that is adjacent to a road carriageway and slopes towards the stormwater drainage collection system.

CEMP Contractors Environmental Management Plan. Cleanfill Refer Section 5.4.1. Also: Material that has no potential to produce harmful effects on the

environment. This material is generally a natural material such as clay, soil, and rock, and such other materials as concrete, brick, or demolition products that are free of combustible or organic materials and are therefore not subject to biological or chemical breakdown.

Alternately, cleanfill has been defined by the ARC as follows: “A filling operation disposing of Soil (excluding soils contaminated by site activities …), Rock, Asphalt (which has no visible or olfactory evidence of volatile hydrocarbons), Asbestos – containing cement materials (including Fibrolite but excluding any friable products which must be disposed of in accordance with the Health and Safety in Employment (Asbestos) Regulations 1998, and the Department of Labour Guidelines for the Management and Removal of Asbestos (Revised) 1999). Plaster/Clay products, Glass Concrete (which includes concrete containing materials of attached structural building materials with a maximum of 5% by volume of attached structural steel and a maximum of 1% by volume of attached wood).

This definition excludes material resulting from a waste treatment process and contaminated marine sediment. Additionally, cleanfilling operations are not for the disposal of unattached structural building materials. It is Council’s view that these materials should be re-used, recycled or disposed of appropriately.


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Cleanfilling operations are permitted to accept only those materials outlined above, or as otherwise defined by the Director, Environmental Management, ARC. These operations are not for the disposal of organic material, vegetation, contaminated soils, or other waste materials (although it is noted that the placement of clean organic mulch or vegetation on batters is not precluded by this definition). Should non-cleanfill material be disposed of to a cleanfill site in the Auckland Region the site will be required to authorise the discharge of contaminants under Section 15 of the Resource Management Act 1991, or remove any non-cleanfill material from the site, whether or not this material is part of the existing fill matrix.”

CMA Coastal marine area: The area of foreshore and seabed below mean high water springs. This boundary is defined within the Proposed Auckland Regional Plan: Coastal.

CNMP Construction Noise Mitigation Plan. Consent Holder Transit New Zealand (Transit). Contract The written agreement between the Consent Holder the Engineer

and the Contractor to the Project to undertake the physical works Contractor Engineering Contractor to the contract. Designation The area designated for use as a State highway or other such

public work within a district plan. DoC Department of Conservation. EEMP Engineers Environmental Management Plan. EMG Environmental Monitoring Guidelines. EMP Environmental Management Plan. Engineer Engineering Consultant to the contract. ESCP(s) Erosion and sediment control plans. ESCP revisions A major revision to an ESCP is considered to be one that will

result in, or require, the establishment or enlargement of a pond, or to other erosion and sediment controls that are established through supporting design calculations. ARC approval is required for major revisions. The ARC also define major field changes, for which ARC approval as well as field and written communications are required, as follows:

• “Elimination of a sediment pond including full or staged decommissioning of sediment ponds as permanent, ponds are commissioned or vegetation permits use of grass swales and silt fences/bunds;

• Addition of a sediment pond;

• Changing the dimensions of an approved sediment pond significantly;

• Increasing the area of contributing catchment of a sediment pond;


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• Bunds (where they may impound water over 500mm depth);

• Changing the type or major location of a temporary waterway crossing;

• Clean water diversions;

• Changes to the earthworks staging requirements of the operation;

• All streamworks;

• Relocation or deletion of diversion channels. Minor revisions are considered to be those changes that impact

upon erosion controls such as daily drain locations, silt fences, and other controls that can typically be constructed without supporting design calculations. The ARC expects that even minor changes to ESCPs be communicated at least verbally, and some (at ARC discretion) may require written approval, and would be expected to be documented in an erosion and sediment control inspection advice report. The ARC define minor changes to an ESCP as including the normal use of the following:

• “Silt fence or super silt fence;

• Hay bales;

• Lengthening or shortening of diversion bunds and contour drains;

• Check dams;

• Storm drain inlet protection;

• Vegetative stabilisation including mulching;

• Topsoiling;

• Erosion control matting;

• Bund construction (where they may impound water under 500mm in depth).”

geotextile A fabric of a given strength and pore size used to control either sediment or water movement.

Harbour Manukau Harbour. HASNO Hazardous Substances and New Organisms Act 1996. HPT Historic Places Trust. L95 The noise level which is equalled or exceeded for 95% of the

measurement period. It is an indicator of the mean minimum noise level and is used in New Zealand as the description for background noise (usually in dBA).

L10 The noise level which is equalled or exceeded for 10% of the measurement period. It is an indicator of the mean maximum noise level and is used in New Zealand as the description for intrusive noise (usually in dBA).


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Lmax The maximum sound pressure level measured during the sampling period.

Leq The time averaged noise level (on a log/energy basis). MCC Manukau City Council. MfE Ministry for the Environment. MHWS Mean high water spring. MoU Memorandum of Understanding. PAHs Polynucleic Aromatic Hydrocarbons. Project SH20 Manukau Harbour Crossing Project. riparian margin For the purposes of this project, the riparian margin commences at

the top of the bank of the primary channel. RMA Resource Management Act, 1991. SCT Sediment Control Team. sediment Eroded material that can include adsorbed contaminants. sediment forebay Small pond designed to capture coarse sediment. sediment generation The amount of sediment that is eroded off any given piece of land

or earthworks area (i.e. may be reduced by erosion controls). sediment yield The amount of sediment finally lost from any given piece of land or

earthworks area (i.e. may be reduced by sediment control devices).

SH1 State Highway 1. SH20 State Highway 20. stabilised Rendering the site resistant to erosion by the application of

compacted basecourse, hydroseeding, mulch, polythene, jute, or similar, or works within low sediment bearing surfaces such as indurated rock. Where revegetation is the method used, then an area may considered to be stabilised once an 80% grass strike has been established.

SVOCs Semivolatile organic compounds. TCLPs Toxicity Characteristic Leaching Potentials. Transit Transit New Zealand. TP10 ARC Technical Publication No. 10: Stormwater Devices Design

Guideline Manual, 1992, and its revision, 2003. TP90 ARC Technical Publication No. 90: Erosion and Sediment Control

Guidelines for Land Disturbing Activities, 1999. TP108 ARC Technical Publication No. 108: Guidelines for Stormwater

Runoff Modelling in the Auckland Region, 1999. TPH Total petroleum hydrocarbons. USLE Universal Soil Loss Equation. Used in the estimation of sediment

generation potentials.


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1 Executive Summary

The Draft Environmental Management Plan (EMP) relates to works associated with the State Highway 20 Manukau Harbour Crossing Project (the Project). The EMP applies Project wide (i.e. from Walmsley Road to Queenstown Road). The Project is described in detail in the Notice of Requirement for the State Highway 20 Manukau Harbour Crossing Project; Volume 1.

Associated with the Project is the need to manage areas of environmental sensitivity, to identify environmental risk issues, and the mechanisms to avoid, remedy, or mitigate these. The purpose of the EMP is therefore to create a template for the working environment of the Project, and to enable both the Consent Holder and the ARC to manage the environmental elements, including any adverse environmental effects of the Project.

Environmental policies are developed within this Plan, which reflects the Consent Holder’s commitment to environmental management, as well as the compliance requirements of resource consents to be obtained from the ARC. The EMP requires the adoption of good environmental management practices for the proposed activities, and identifies the mechanisms to be utilised to avoid, remedy or mitigate potential adverse environmental effects. The EMP covers all elements of the project, and outlines appropriate environmental control measures and standards to be implemented during design, construction and operation.

This EMP is to be supported by a number of other management plans, to be prepared at various stages of the Project and submitted to the ARC for approval prior to implementation, including the Environmental Monitoring Guidelines (EMG), and the Contractor’s and Engineer’s Environmental Management Plans (CEMP and EEMP).

The EMP is proposed as the mechanism by which performance-based consent conditions for the entire Project will be implemented. This provides for the normal process of design iterations and modifications to construction techniques subsequent to the granting of consents.

The overall approach to environmental management for the Project includes identifying all major activities within the EMP. These activities are then considered with the objective of anticipating and minimising adverse environmental effects through the use of good management practices and by implementing the best practicable option. Control measures are to be implemented in the course of the design, construction, and operation of the Project to avoid, where possible, or remedy/mitigate adverse environmental effects. These controls and work methodologies will be identified in more detail within the EEMP and CEMP as necessary

Should a review of the EMP be requested by the Consent Holder’s contractor, approval of modifications will be required from the Consent Holder and ARC if the amendments sought relate to those areas (denoted in the EMP) that fall within the ARC jurisdiction.



2 Introduction

The Project forms part of Transit’s Western Ring Route Strategy to provide a western corridor through the Auckland Region, and therefore a viable alternative to SH1.

The Project will widen SH20 between Queenstown Road and Walmsley Road Interchanges from four lanes to six lanes, with bus priority on shoulder lanes where practical. Eight lanes will be provided between the Rimu Road and Gloucester Park interchanges. Mangere Bridge will be duplicated to the east (i.e. a second bridge will be built) so that four traffic lanes and a shoulder lane for bus priority will be provided in each direction. Pedestrian and cyclist usage will continue to be provided along the line of the Old Mangere Bridge by way of a replacement structure (Mangere Footbridge).

The existing Gloucester Park split interchange will be upgraded to a grade separated diamond arrangement connected to Neilson Street. The Project will require alterations to local streets (Rimu Road, Mahunga Drive, Neilson Street, Gloucester Park Road and Orpheus Drive) and modification to access arrangements to surrounding properties affected by the upgraded interchange at Gloucester Park Road. The Orpheus Drive modifications require reclamation in the adjacent Coastal Marine Area (CMA).

The Rimu Road/Mahunga Drive Bridge will be replaced to allow motorway widening. Further south at Tararata Creek a new off ramp bridge and widened motorway bridge will be required.

At the Queenstown Road Bridge, additional retaining walls and abutments will be required. The Beachcroft Avenue and Hastie Avenue footbridges will also need to be replaced to allow motorway widening.

This Plan relates to works which are part of the Project. There are a number of key stakeholders in the Project. These include Transit, ACC, MCC and the ARC. Transit will be the Consent Holder for the project.

2.1 Purpose of Environmental Management Plan

Associated with the Project is the need to manage areas of environmental sensitivity, to identify environmental risk issues, and the mechanisms to avoid, remedy, or mitigate these. The purpose of the document is therefore to create a template for the working environment of the Project, and to enable the Consent Holder to manage the environmental elements, including any adverse environmental effects of the Project.

This EMP is proposed as the mechanism by which performance-based consent conditions for the entire Project will be implemented. This provides for the normal process of design

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iterations and modifications to construction techniques subsequent to the granting of consents1,2.

Those parts of the EMP that are highlighted fall within the jurisdiction of the ARC, and relate to those matters that are the subject of the resource consent applications and subsequent consent conditions obtained from the ARC. Those consents being:

• Coastal permits;

• Land disturbance activities; and

• Stormwater diversion and discharge.

The EMP requires the adoption of good environmental management practices for the proposed activities, and identifies the mechanisms to be utilised to avoid, remedy or mitigate potential adverse environmental effects. The EMP covers all elements of the project, and outlines appropriate environmental control measures and standards to be implemented during design, construction and operation.

2.2 Plan Status

The highlighted provisions of the EMP will be required to be complied with as a condition of the resource consents imposed by the ARC. As previously outlined, the highlighted sections of the EMP are those that fall within ARC jurisdiction and require ARC approval for any amendment (refer Section 2.5).

Consequently, the EMP (along with any other conditions of resource consent) will take priority over any terms and specifications contained within any contractual documents between the Consent Holder and any other party (e.g. the Contractor). Compliance with the conditions of consent (including the condition requiring compliance with the EMP) is to be a term of the relevant contracts.

2.3 Related Documentation

This EMP is to be supported by a number of other management plans, to be prepared at various stages of the project, and submitted to the Consent Holder and the ARC for approval prior to implementation. These are as follows:

• Environmental Monitoring Guidelines (EMG);

• Engineer’s Environmental Management Plan (EEMP); and

• Contractor’s Environmental Management Plan (CEMP). 1 Provided that they are in general accordance with the applications for consent and subsequent conditions of consent, and provided that they meet the performance based requirements identified within this document. 2 Mechanisms for revision to this document have been identified. This provides for instances where it is found that the objectives cannot be met. However approval of an alternative is dependant upon demonstrating the overall objectives can be met, or that offsetting mitigation can otherwise be provided.



The EMG identifies the monitoring requirements and responsibilities relative to the construction phase of the Project and is aimed at monitoring compliance with the conditions of consent and the EMP, and checking outcomes in the receiving environment.

The EEMP and the CEMP are to be developed by the Engineer and the Contractor respectively to demonstrate how the requirements of the conditions of consent, the EMP and the EMG are to be implemented.

Matters to be addressed within each of these plans have been identified in the following sections of this EMP. The relationship between the conditions of consent, the EMP and the various management plans is summarised within Figure 1. Responsibility for administration and implementation of the EMP and EMG will remain with the Consent Holder.

As required by the (recommended) conditions of the Notice of Requirement and in addition to the management plans detailed above the Requiring Authority is required to provide operational management plans that the contractor will prepare and implement, subject to approval from ACC and MCC. The operational plans include: a Construction Management Plan; a Stakeholder Management Plan; a Safety Management Plan; and a Traffic Management Plan. The operational management plans are described in Chapter 2, Volume 1, of the AEE.

2.4 Authority for Administration of This Plan

This EMP is to form part of the contract documents for the Project. In general terms, the authority in regard to the administration of this Plan is as follows:

• Consent Holder:

The Consent Holder is required to implement the EMP through conditions of consent and the Contract, and has the authority to seek and make changes to this EMP (where, in the case of the highlighted portions of this Plan, these changes have been approved by the ARC).

• ARC:

The highlighted sections of the EMP fall within the jurisdiction of the ARC and relate to those matters that are the subject of the resource consent applications. Any changes to the highlighted sections of the EMP cannot be amended without the approval of the ARC.

• Engineer:

The Design Engineer is required to develop a design that reflects the requirements of the EMP. The Engineer is required to implement the EMP through the conditions of consent and the Contract. The MSQA Engineer is required to monitor the Contractors performance in implementing the EMP. The Engineer may seek changes to the EMP via the Consent Holder.



• Contractor:

The Contractor is required to implement the EMP through the conditions of consent and the Contract. The Contractor may seek changes to the EMP via the Engineer.

2.5 Mechanisms for Revision

The primary reason for revision of this EMP is likely to be due to the change of activities or methods used on the site. While changes may be suggested by any party, any revisions must comply with all the conditions of the consents, Notices of Requirement and HPT authorities granted in respect to this Project must be acceptable under the Conditions of Contract. All revisions to the highlighted sections of the EMP must be approved by the ARC and implemented by the Consent Holder.



Figure 1: Environmental Management Framework

Environmental Management Plan (EMP)

Designation Conditions

Resource Consent

Conditions

Assessment of Effects

Best Practice Guidelines

CONSENT HOLDER

Environmental Monitoring Guidelines

(EMG)

Engineer’s Environmental

Management Plan (EEMP)

ENGINEER

Contractor’s Environmental Management Plan (CEMP),

and Operational Management

Plans (Construction, Safety, Stakeholder and

Traffic Management)

CONTRACTOR



3 Mitigation of Adverse Effects

This Section sets out the Project’s environmental principles, and summarises the methods that will be used to mitigate any potential significant adverse effects on the surrounding environment.

3.1 Environmental Objective

To provide an integrated, safe, responsive and sustainable land transport system within the Project area consistent with any conditions of resource consent and any conditions imposed by the designation.

3.2 Environmental Principles

All works are to be undertaken in compliance with all current New Zealand legislation and the construction and operation of the Project will utilise the best practicable options to ensure adverse environmental effects are avoided where possible, or remedied/mitigated.

3.3 Environmental Methods

The implementation of the environmental management plans (including the EMP, EMG, the EEMP, and the CEMP), are the methods that will:

• Assist in the prevention of significant adverse environmental effects; and

• Mitigate adverse effects during design, construction and operation of the Project, through which the environmental objective and environmental principles will be implemented.

3.4 Environmental Management Approach

The overall approach to environmental management for the Project is as follows:

• All major activities to be undertaken as part of the Project, including those for which resource consents are required are identified within this EMP. With the aim of anticipating and minimising adverse environmental effects through the use of good management practices and by implementing the best practicable option, activity specific controls have been set out within this Plan;

• The activity specific controls are to be implemented in the course of the design, construction, and operation of the Project to avoid, where possible, or remedy/mitigate adverse environmental effects;

• The Engineer will identify design and operational elements within the EMP and check that these have been complied with. In addition, the Engineer will develop the EEMP, which will identify additional checks and issues that will need to be followed through during construction. These will include issues arising out of the



design phase that need specific follow up during construction to match the design with the overall environmental objectives identified within the resource consents and/or the EMP;

• The Contractor will further expand upon the activities to be undertaken during the construction of this Project within the CEMP. The CEMP will set out in greater detail the specific construction methodologies, strategies, procedures, maintenance programmes and operation schedules that are to be implemented to demonstrate compliance with the EMP during the construction phase of the Project; and

• The EMG will set out the monitoring requirements for the Consent Holder, the Engineer, and the Contractor. The monitoring will be used in the first instance to check that the activity specific controls have been implemented. This aims to identify activities with the potential to result in adverse environmental effects and will aim to prevent these effects from occurring through early identification and response. The EMG will also set out baseline monitoring requirements for the receiving environment prior to construction activities commencing, together with monitoring of the receiving environment to be carried out during construction to verify the assumptions made within the assessment of effects, and as a check that the activity specific controls are appropriate. Environment monitoring includes both scheduled (regular) monitoring and triggered (response) monitoring.

4 Environmental Management Plan Requirements

This Section sets outs the minimum requirements for inclusion within the other Project Environmental Management Plans.

4.1 Environmental Monitoring Guidelines

The EMG sets out the monitoring responsibilities for the project. The focus of the environmental management approach is upon the anticipation and prevention of adverse environmental effects, and therefore monitoring is a crucial component. Whilst the monitoring will comprise some quantitative receiving environment monitoring, it is intended that the primary focus be placed upon field checks of the environmental control and mitigation devices or measures to reduce the risk of failure.

Requirements in relation to the EMG are as follows:

4.1.1 Prior to the commencement of works, the Consent Holder shall submit a document titled “Environmental Monitoring Guidelines SH20 Manukau Harbour Crossing Project dated” (“EMG”) to the Manager, for written approval.

4.1.2 The EMG shall be based upon the document entitled “Draft Environmental Monitoring Guidelines SH20 Manukau Harbour Crossing Project” submitted with



the application for the Project. The EMG shall set out and establish the monitoring to be undertaken in relation to the Project.

4.1.3 The EMG shall include the following details with regard to heavy rainfall events:

• The criteria to be used to determine what a heavy rainfall is and when heavy rainfall events capable of causing unacceptable adverse impacts are occurring;

• The specific monitoring to be undertaken during such heavy rainfall events; and

• Details of possible actions that shall be undertaken if unacceptable adverse impacts occur.

4.1.4 As part of the EMG, the Consent Holder shall also include an environmental monitoring program prepared by a suitably qualified and experienced environmental scientist. The environmental monitoring program shall include, but not be limited to the following:

• Monitoring macroinvertebrates in the Mangere Inlet on one occasion each year in late summer. The protocol for macroinvertebrate sampling shall be established by a suitably qualified and experienced biologist;

• Identification of environmentally acceptable trigger levels in relation to turbidity, sediment deposition and effects on macroinvertebrates. Contingency measures, as defined in Condition 5.5 are to be undertaken when such trigger levels are exceeded;

• Monitoring sediment build up between the proposed reclamation and the breakwater adjacent to Orpheus Drive; and

• Reporting procedures.

4.1.5 The EMG shall specify action to be taken should any of the trigger levels specified in the EMG be reached. Provisions in this regard shall include, but are not limited to the following:

• A process for notification and consultation with the Manager and any other agreed parties to determine what remedial action or alteration of operations is appropriate in the event trigger levels are exceeded;

• A verification process (i.e. more intensive monitoring) to determine whether remedial action has remedied or mitigated the detected effects.

4.1.6 Monitoring specified in the EMG shall be undertaken for a period in accordance with the likely time horizons of the specific effect being monitored and monitoring



periods shall be specified in the EMG. The maximum time period for monitoring as specified in the EMG will be no more than three years following the opening of the Project.

4.1.7 The Consent Holder shall carry out monitoring in accordance with the approved EMG, and shall maintain records detailing:

• The monitoring undertaken;

• The erosion and sediment controls that required maintenance;

• The time when the maintenance was completed; and

• Areas of non-compliance with the ‘Environmental Management Plan’ and the reasons for the non-compliance.

4.1.8 The records shall be forwarded to the ARC monthly, or within 5 working days of being requested to do so.

4.1.9 No amendments may be made to the EMG unless approved by the ARC.

4.2 Engineer’s Environmental Management Plan

The EEMP identifies environmental responsibilities during the construction phase of the project. The purpose of the EEMP is to provide a tool to minimise the risk that design elements, and specific environmental requirements identified within the conditions of consent and Notices of Requirement, the EMP, or the EMG are overlooked.

Requirements in relation to the EEMP are as follows:

4.2.1 The EEMP shall include the following:

• Construction drawings, specifications and any contract documents for the proposed works are to be submitted to the ARC. The ARC shall consider and approve those aspects that are within the jurisdiction of the ARC pursuant to authorisations being sought under the Resource Management Act (RMA), 1991. The approval shall be included within the EEMP. The detailed design drawings, specifications, and any contract documents submitted to the ARC for approval shall contain the following:

• Details of how erosion and sediment controls, consent conditions, and the requirements of the environmental management plans will be administered during construction;

• Details of the stormwater quality treatment devices, together with outfall structure details and location, estimated treatment efficiencies, and long term operational and maintenance requirements;



• Drainage details;

• A landscaping plan detailing the planting to be undertaken in association with the works;

• Details of environmental issues requiring specific follow up during construction as derived from the conditions of consent, EMP, and EMG. This will include, but not be limited to checking that the Contractor is monitoring erosion and sediment controls, following up design details within stormwater treatment devices, and specific restrictions in relation to the CMA;

• The identification of appropriately qualified staff who have clearly defined roles and responsibilities to ensure that the conditions of consent, and the environmental requirements identified within the EMP and EMG are implemented throughout the contract;

• The person(s) responsible for environmental matters during construction shall have successfully completed the ARC Environment Industry Registration Programme for Erosion and Sediment Control: Plan Implementers Course. In the event that the ARC do not hold the course prior to the commencement of construction, the Engineer shall demonstrate that the nominated person(s) is/are enrolled on the next course. The Engineer shall forward evidence of successful course completion to the Consent Holder and the ARC at the end of the course;

• Responsibilities and lines of communication for personnel responsible for environmental matters on behalf of the Engineer; and

• Identification of a Sediment Control Team (SCT) to be led by the Engineer. In addition to the Engineer, the SCT shall include appropriate representatives from the Contractor (and if appropriate key subcontractors), and the ARC. The SCT shall meet and review erosion and sediment controls on a fortnightly basis.

4.2.2 The Engineer in consultation with the relevant Contractor shall prepare an earthworks staging programme in accordance with the conditions of consent to be submitted to the ARC for approval prior to the commencement of works.

4.2.3 The EEMP shall be submitted to the ARC for approval prior to construction works commencing.

4.2.4 No significant amendments shall be made to the EEMP without the approval of the ARC.



4.3 Contractor’s Environmental Management Plan

The CEMP is to demonstrate how the Contractor will actually implement the requirements of the conditions of consents, this EMP and the EMG. The purpose of the CEMP is to set out in writing the mitigation measures that will be put in place for the duration of the project. This provides additional hold points and checks during the construction phase of the Project where there is the greatest potential for adverse environmental effects.

CEMP requirements are as follows:

4.3.1 The CEMP is to include an Erosion and Sediment Control Plan(s) (ESCP(s)) for each stage of construction:

• The ESCPs (as a minimum) shall include:

• Contour information at a suitable interval;

• Details of erosion and sediment controls;

• Supporting calculations including universal soil loss equation (USLE) estimates for each area contributing to a sediment control pond;

• Catchment boundaries for the sediment controls;

• Location of the works, and cut and fill operations;

• An appropriate scale;

• A map detailing slope angles within the designation;

• Maintenance and inspection requirements;

• Locations of all devices plus sizes of contributing areas, volume (where applicable) and location relative to the road chainage.

• The ESCPs, including the staged submission of plans, shall be submitted to the ARC for approval at least one week prior to works in that area commencing.

• Amendments shall be made to ESCPs to reflect changes to the site over the duration of the project.

4.3.2 During construction, the ESCPs shall be amended to incorporate as-built information for any temporary sediment control ponds.

4.3.3 The CEMP shall include a maintenance programme for haul and access roads (if any) in accordance with the requirements of this EMP.



4.3.4 The CEMP is to include a construction methodology and timetable which shall include:

• A brief discussion of how the proposed techniques will minimise erosion; and

• Key stages and phases of the project.

4.3.5 Prior to the commencement of any works, the Contractor (via the Engineer) shall advise the ARC, in writing, of the date of commencement and subsequently the date of completion of the proposed works. This condition shall apply to each stage of the proposed works identified in the approved CEMP.

4.3.6 The CEMP is to include details of how subcontractors on the site will be required to comply with erosion and sediment controls, consent conditions, and the requirements of the environmental management plans.

4.3.7 The CEMP shall include a dust strategy in accordance with the requirements identified within this document.

4.3.8 The CEMP shall set out mitigation and contingency measures for (but not limited to) the following:

• Erosion control and construction material loss;

• Oil spills;

• Failure of protection works or earthworks;

• Litter control;

• Dust control;

• Tracking of dirt onto public Roads;

• Water collection management;

• Noise control; and

• Traffic on site and at exit/egress to public roads.

4.3.9 The CEMP shall include environmental emergency response procedures, which shall include details of appropriate action to be taken, all responsible personnel, and means of notifying emergency response agencies.

4.3.10 The Contractor shall maintain a record of complaints. The Complaints Register shall form part of the CEMP and shall, as a minimum, include:

• Complainant details, including location;



• Area of works relating to complaint;

• Nature of complaint/likely incident giving rise to complaint;

• Time and date complaint received and by whom;

• Course of action including name of person to be responsible for implementing response action(s), changes to prevent re-occurrence or mitigate effect;

• Verification action occurred;

• Record of follow up with complainant; and

• Date complaint issue closed.

4.3.11 The CEMP shall include an emergency response procedure that shall incorporate the following requirements:

• In the event of a non-compliance with resource consent conditions (or other legislation), or an incident occurs that results in a significant adverse environmental effect, the following shall occur:

• The Contractor shall take immediate action to stabilise the situation (i.e. right a drum, cease work, turn off or move machinery, deploy spill equipment). All spills shall be contained, recovered and disposed of appropriately;

• The Contractor shall contact the Engineer and the ARC within 24 hours or sooner if appropriate to the situation;

• The Contractor shall contact other potentially affected parties if the incident has the potential to have effects beyond the site that would affect a given party;

• The Contractor (and the ARC if possible) shall determine any further response required. The Contractor shall take all steps necessary to mitigate the incident. External agencies shall be utilised if appropriate to the situation; and

• Should remedial action and/or monitoring be required, an appropriate course of action shall be determined by the ARC in association with the Contractor, and if necessary, external specialists.

• The Contractor shall prepare an incident report that shall include as a minimum:

• Description and location of incident;

• Likely cause;



• Potential or actual effects;

• Details of response including mitigation and remedial action taken;

• Preventative action/changes to prevent a re-occurrence; and

• Monitoring results.

• The Incident Report shall be forwarded to the Engineer and the ARC within one week of the incident and shall be attached within the CEMP. Follow up reports including any monitoring results shall be forwarded according to time frames determined during incident response meetings with the ARC.

4.3.12 All non-compliances with the consent conditions, the EMP and the CEMP must be recorded. Information will include the reason for the non-compliance, the expected duration, the action taken, what will be done to prevent a re-occurrence, any remedial works required.

4.3.13 The CEMP shall include details of security systems proposed for any refuelling and maintenance depots in accordance with the requirements of this EMP.

4.3.14 The CEMP shall include a dewatering methodology for the dewatering of piles and works within the CMA in accordance with the requirements of this EMP.

4.3.15 The Contractor shall maintain a record of the disposal site of all excavated materials disposed of off the site including any verification test results of materials disposed of as cleanfill. The audit trail shall be included within the CEMP and copies forwarded to the Engineer at the completion of construction or as otherwise requested.

4.3.16 The CEMP shall include a Construction Noise Management Plan (CNMP) in accordance with the conditions of the Designation.

4.3.17 No construction or ancillary equipment, or buildings shall be moved on to the site prior to the completion, submission, and approval of the CEMP. The Plan is to be submitted to and approved by the Engineer in addition to ARC approval to specific components of the Plan. This is to ensure that construction facilities are established in appropriate locations and meet the requirements of this EMP.

4.3.18 The CEMP and its components, including the ESCPs are not static. The CEMP is to be updated throughout the course of the Project to reflect changes to components of the Project and the ESCPs.

4.3.19 The CEMP shall identify:

• An appropriately qualified and experienced environmental quality systems manager, who shall be responsible for ensuring compliance with the conditions of



consent, the EMP, EMG and the Contractors own CEMP throughout all phases of the contract;

• A chain of responsibility for managing environmental issues and details of responsible personnel for all phases of the Project (e.g. for refuelling and maintenance depots, the names, details and relevant management experience of the nominated staff shall be provided);

• Records to be maintained that demonstrate compliance with the provisions of the CEMP. Records are to be available for inspection and audit; and

• The person(s) responsible for implementing appropriate erosion and sediment controls for the works during construction. That person shall have successfully completed the ARC Environment Industry Registration Programme for Erosion and Sediment Control: Plan Implementers Course.

4.3.20 The CEMP shall be auditable and shall be audited by the Engineer to ensure the Contractor is implementing the documented procedures.

4.3.21 The CEMP shall detail, and the Contractor shall implement, a programme for the education and control (with respect to the environment) of employees and subcontractors to ensure that all personnel are briefed on environmental issues prior to commencing work. It is important that specific training and a briefing be provided prior to commencing works overall, and in particular, prior to commencing within the CMA. A record shall be kept of all training. Training shall incorporate:

• The implications of the Project construction on the down gradient receiving environment,

• The importance of erosion and sediment control and exemplary on-site environmental management, and

• An understanding of the need to recognise and provide measures for the prompt response to unusually intense/sustained rainfall as part of the erosion and on-site environmental management practices.

5 General Requirements

This Section of the EMP comprises:

• General environmental requirements that apply to all activities;

• Identification of management controls for specific issues that could affect the activities identified in the subsequent sections of this Plan; and the

• Consideration of the need for chemical treatment of sediment retention ponds.



The requirements of this Plan shall be incorporated into the contract documents developed for the Project. This will ensure compliance with the Project environmental objectives and policies together with compliance with resource consent requirements.

The Consent Holder will be responsible for ensuring that the Project requirements as set out within the environmental management plans and any resource consents are complied with as a function of all contracts relating to the Project. This is also to include any contracts or physical works documentation relating to the operational aspects of the Project.

5.1 General Consent Holder Requirements

General Consent Holder requirements are set out below. It is the responsibility of the Consent Holder to ensure that, where necessary and/or appropriate, such requirements are included within contract documentation to ensure implementation in all phases of the project.

5.1.1 The construction drawings, specifications, and any contract documents shall address matters relating to the maintenance and management of the works, environmental protection measures to be employed, and contingency planning mechanisms. The Consent Holder shall also ensure that this is a requirement of the construction contract/physical works documentation.

5.1.2 All contract/physical works documents shall comply with the EMP and all relevant designation and resource consent conditions. The Consent Holder shall also ensure that this is a requirement of the construction contract/physical works documentation.

5.1.3 All contract/physical works documents shall contain a copy of the designation conditions, any approved outline plans, copies of all resources consents and HPT authorities granted for the project, this EMP and the EMG. The Consent Holder shall also ensure that this is a requirement of the construction contract documentation.

5.2 General Implementation Requirements

During the design phase of the Project there will be matters that need to be incorporated within the designs to ensure the construction and operational phases of the Project meet the Project requirements identified within this Plan. It is the responsibility of the Consent Holder, via the Engineer to ensure that, where necessary and/or appropriate, such requirements are included within construction contract/physical works documentation or forwarded to the Consent Holder to ensure implementation in other phases of the project.

The Consent Holder (via the Engineer and/or Contractor) shall:

5.2.1 At an early stage within the design process hold a briefing session with the ARC and the engineering designers of the environmental aspects of the Project.

5.2.2 Implement monitoring procedures in accordance with the requirements of the EMG.



5.2.3 Where the Project passes through the CMA appropriate steps shall be taken to minimise habitat loss, wildlife isolation effects and construction impacts.

5.2.4 Utilise designs that incorporate construction methods that endeavour to minimise the potential impact upon the environment.

5.2.5 In regard to the Duplicate Bridge and Mangere Footbridge and fender structure, a numerical model study of tidal flows under the bridges, including the ‘before’ and ‘after new bridge’ situation and tidal exchange in the western basin, shall be carried out during the design phase. This shall include bathymetric information of the existing seabed and future sea bed levels. This will provide input into finalising the layout and shape of the pier foundations to mitigate localised long term effects.

5.2.6 A photo record should be made of the estuary before and after construction as a coastal baseline record.

5.2.7 In regard to the proposed reclamations, the design phase will need to finalise layouts and ensure that the minimum amount of land is reclaimed both for temporary and permanent reclamations and shall limit the extent of the proposed temporary reclamation adjacent to the northern end of the proposed Duplicate Bridge to avoid an adjacent area of high natural value. Suitable fencing shall be provided to avoid the encroachment of construction plant onto this area.

5.2.8 The project should provide mitigation measures for long term effects by including remediation of the southern foreshore in the area of the existing Mangere Bridge by removal of debris and provision of landscaping. Also the temporary reclamation south of Onehunga Harbour Road is proposed to become an extension of the adjacent salt marsh after construction.

5.2.9 Remove all spoil from excavations for bridge piers and reclamation foundations from the CMA.

5.2.10 Restore the seabed to natural levels when temporary reclamations are removed.

5.2.11 Minimise the use of construction machinery outside the footprint of works that are constructed within the CMA.

5.2.12 Use reclamation fill that does not release any contaminants into the CMA.

5.2.13 Remove all displaced mangroves from the CMA.

5.2.14 Prior to the start of physical works, obtain all resource consents and authorities required (including those required under the Hazardous Substances and New Organisms Act (HASNO), and the Historic Places Act).

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5.2.15 Sequence construction activities to minimise disturbance and impacts upon the environment. Any enabling works should be timed to avoid leaving unstabilised areas over a winter period.

5.2.16 Set out construction details, and set up any subconsultant/subcontractor agreements, to ensure environmental requirements are implemented, and compliance with consents and permits is achieved.

5.2.17 Ensure that at all times reasonable access is maintained to private properties not directly affected by construction and operation.

5.3 Archaeological Requirements

It should be noted that both identified and unidentified archaeological sites are protected by the Historic Places Act 1993. As such, an Authority is required to damage, modify or destroy any archaeological site. In the case of the uncovering of previously unidentified sites, the Archaeologist will direct a course of action that will comprise mitigation works. The Consent Holder shall therefore include an Archaeologist as part of the team for the duration of the design and throughout the construction of the Project.

The conditions of the NOR include archaeological mitigation conditions that the Consent Holder must comply with.

Specific archaeological requirements to be complied with by the Contractor are as follows:

Detailed protocols for the management of archaeological and waahi tapu discoveries shall be specifically discussed with tangata whenua prior to construction.

5.3.1 If any archaeological sites, including human remains are exposed during site works then the following procedures shall apply:

(a) Immediately after it becomes apparent that an archaeological or traditional site has been exposed, all site works in the immediate vicinity shall cease;

(b) The Requiring Authority shall immediately secure the area so that any artefacts or remains are untouched; and

(c) The Requiring Authority shall notify Tangata Whenua, the New Zealand Historic Places Trust and Council within 24 hours that an archaeological site has been exposed so that appropriate action can be taken. Works shall not commence in the immediate vicinity of the archaeological site until any approval required from the NZ Historic Places Trust is obtained.

5.3.2 Tangata Whenua Contact List:



5.3.1 Primary Contact 5.3.2 Representative Group/Organisation

John Kerr Te Puea Marae

Ngarimu Blair Ngāti Whatua o Orakei Maori Trust Board

Saul Roberts Te Kawerau a Maki Trust

Ray Cooper Huakina Development Trust

Karl Flavell Ngaati Te Ata (Awaroa Environment)

Peter Karaka and Pita Turei

Nga Tai Ki Tamaki Tribal Trust

5.4 Potential Soil Contamination

SH20 runs through an already modified environment. For much of the route, stormwater is collected within grassed swales and drainage channels. Over time it is likely that contaminants have built up in the soils within these areas.

Once excavated, this material might not be suitable for reuse on the site if it contains contaminants at concentrations above acceptable guideline values. This may therefore necessitate the removal of that material from the site and appropriate disposal to a controlled landfill.

Alternatively, the material might only be marginally contaminated (relative to the existing land use) but require off site disposal for other reasons (e.g. engineering unsuitables, or excess material). It is therefore equally important to identify and manage these materials so that contaminated material that is not suitable for use as cleanfill elsewhere is also disposed of to a controlled landfill.

The means of assessing soils and other materials in the areas relative to contaminant levels is addressed within this section.

Prior to the main construction works occurring, the Consent Holder shall comply with the following:

5.4.1 In areas where existing swales and grassed berms areas (receiving stormwater runoff) are to be excavated the Consent Holder shall undertake testing of the sediments prior to construction to categorise the sediments as follows (note that definition of Engineering Unsuitables is not included as part of this process):

• Cleanfill:

• Able to be reused on site subject to approval by the Engineer, or

• Able to be taken off site for use as cleanfill in accordance with statutory requirements, and

• Complies with the ARC definition of cleanfill (refer Glossary); and



• Contains contaminant concentrations that are below background concentrations as defined by application of the:

• ARC Technical Publication 153 (TP153) Background Concentrations of Inorganic Elements in Soils from the Auckland Region, ARC 2002,

• As established through the sampling of control sites in appropriate areas adjacent to the route,

• Guidelines for the Assessment and Management of Potentially Contaminated Sites (Australian and New Zealand Environment and Conservation Council (ANZECC), 1992),

• Ministry for the Environment (MfE) Guidelines for Assessing and Managing Hydrocarbon Contaminated Sites in New Zealand (1997).

• Marginally Contaminated:

• Able to be reused on site subject to approval by the Engineer (with respect to structural integrity), and approval of the ARC (with respect to contaminants concentrations; consent may be required), or

• Able to be taken off site but requires disposal to a disposal facility consented to receive contaminated materials.

• Contaminated:

• Not able to be reused on site due to contaminant concentrations. Able to be taken offsite for disposal to a facility consented to receive contaminated materials.

• Hazardous:

• Not able to be reused on site due to contaminant concentrations. Pre-treatment required prior to off site disposal to a facility consented to receive contaminated materials.

The primary issue during construction is to ensure that any contaminated materials are disposed of appropriately. Therefore, the Consent Holder shall ensure that the following occurs during construction:

5.4.2 In the event that the initial testing indicates that contaminated soils are an issue for this project, then the Consent Holder shall require the Engineer to develop construction requirements for the management of any contaminated and/or landfill materials. The Engineer shall include these within the Technical Specifications. The specifications should be approved by the ARC. The Specifications shall require, as a minimum:

• The Contractor to develop a specific management plan as part of their CEMP to address the handling and disposal of contaminated and/or landfill materials. This shall include, in the least:

• Health and safety requirements specific to the contaminants of issue;



• Additional site controls (such as wheel wash, restricted site access, direct loading out to trucks, run off collection etc);

• Leachate management (and if necessary collection) and runoff monitoring for the area of the landfill;

• Methodologies and controls for working in trenches within the landfill (should this be proposed);

• Landfill gas monitoring procedures, emergency response, and work restriction requirements (equipment controls etc);

• Disposal requirements;

• Procedures for maintaining disposal records.

• Testing of excavated materials to be undertaken in accordance with Figure 2 of this EMP to validate the results of the initial testing as the materials are removed from the site. Sufficient time should be allowed for this testing and interpretation to occur (this may require three weeks or more);

• Sample collection techniques, quality control programmes, and methods of analysis, shall be in accordance with the MfE Guidelines for Assessing and Managing Hydrocarbon Contaminated Sites in New Zealand. Analytical limits of detection shall be less than environmental criteria; and

• Results shall be compared against the environmental criteria listed in 5.4.1.

5.4.3 Only cleanfill or, if firstly approved by the ARC (and any additional consents are obtained should these be required) marginally contaminated material may be reused on the site (refer 5.4.1). All other materials excavated on the site must be taken off site for appropriate disposal and an audit trail of the disposal retained.



Figure 2: Approach for Managing Potential Contaminants During Construction

Undertake testing

(apart from preconstruction testing ~1 sample / 1,000m3)

Do contaminants exceed environmental criteria for cleanfill sites?

Compare with background, ARC TP153, ANZECC, MfE criteria, and if appropriate the NOAA Guidelines. Results must be below all relevant criteria.

If there is any doubt results should be forwarded to ARC to clarify whether the material can be reused on the site and if so whether consent is required.

To cleanfill site / reuse

on site

No Yes

Develop and implement Management Plan including:

• Health and safety requirements • Additional site controls (eg runoff

containment) as appropriate • Determine disposal options • Consent from ARC if required for the

handling and disposal of the material • Audit trail for the waste

Undertake and document validation testing along base of excavation in areas where

overlying contaminated materials are

At l

east

two

wee

ks re

quire

d fo

r ana

lysi

s

Is further testing required to better define the issue(s) spatially and to assess options?

Yes

Undertake further testing

No

Dispose of contaminated materials to an appropriate (and consented) disposal facility

At least two weeks required for analysis



5.5 Chemical Treatment Criteria

When completing ESCPs that incorporate sediment retention ponds, the Contractor will consider the matters contained in Figure 3. In particular, consultation with the ARC should take place. It is noted that a formal approval process, pursuant to the conditions of consent will occur for each and every ESCP, however, discussion prior to the submission of an ESCP will assist with the approval process.

In addition to the initial consideration of chemical treatment, visual monitoring will be undertaken to assess the performance of ponds that are not utilising chemical treatment (as well as those that are). If this monitoring (completed by the Engineer, Contractor and ARC) determines that a pond that is not chemically treated is leading to more significant discharges than were expected, due to soil conditions, catchment areas or other on site management matters, the criteria as stated allows for the further consideration of chemical treatment is to be utilised if deemed necessary.



Figure 3: Chemical Treatment Criteria

No problems/issues

Assess each sediment pond and receiving

environment, duration of works,

methodology, land availability etc

Routine environmental monitoring and compliance monitoring of sediment pond

Build standard sediment pond

Consider options in consultation/site visit

with ARC

Management or maintenance issues?

Assess performance of sediment

pond/complaints etc

Design/Build pond and flocculation unit and Chemical

Treatment unit

Build larger/redesigned pond or implement

alternative measures

Improve management or maintenance

Consider chemical treatment in consultation with ARC (use criteria

above)

Install Chemical Treatment

Higher level of treatment appropriate

Chemical Treatment appropriate BPO

No major issues

Larger pond BPO

Pond under performing/adverse effects

Standard pond BPO

Pond undersized

No

Chemical treatment appropriate

Yes

Chemical treatment inappropriate/unnecessary



6 Activity Specific Requirements

6.1 Erosion and Sediment Control

The Auckland Regional Plan: Sediment Control and ARC Technical Publication No. 90 (1999) set out the requirements and guidelines for earthworks. As previously stated, compliance with the EMP is a condition of the approved consents. The EMP requires the preparation of a CEMP, which includes the preparation of an erosion and sediment control plan (ESCP). The ESCP is are required to comply with the guidelines set out in the Technical Publication No. 90 (TP90).

Erosion control is the most important aspect of the management of sediment from the earthworks operations. The Contractor is to ensure that erosion and sediment control is actively managed throughout the construction phase of the Project and reflects the changing status of the project. Controls within contract documentation shall be sufficient to ensure environmental aspects of the Project are implemented and administered appropriately and that there is sufficient control of subcontractors. The control of subcontractors should be well defined to prevent erosion and sediment controls being overlooked by either party.

The management of the bulk earthworks is also considered to be an integral component of erosion control, and the Contractor shall actively manage the earthworks to meet the requirements set out within the following sections of this Plan. Where environmental requirements and/or objectives conflict, it is the intention of this Plan that the best overall environmental outcome be implemented. The Consent Holder shall implement all aspects of this Project in accordance with that intent.

6.1.1 Erosion Control

The Contractor shall implement the following erosion controls:

6.1.2 All erosion and sediment control measures shall be installed in general accordance with TP90 except where a higher standard is contained in the resource consents, in which case this higher standard shall apply.

6.1.3 All sediment retention ponds shall be constructed to withstand the 1% AEP frequency storm event without failing structurally (in part or in whole), and shall incorporate an emergency spillway to accommodate that event.

6.1.4 The Consent Holder shall submit a certificate signed by one of the appropriately qualified and experienced staff, to certify that the erosion and sediment controls have been constructed in accordance with the Erosion and Sediment Control Plan(s) approved under the resource consents, following the construction of the controls and prior to the commencement of bulk earthworks. Certified controls shall include sediment retention ponds, diversion channels/bunds and check dam



structures. This requirement shall also apply to sediment retention facilities that are constructed during site development. Information supplied shall include:

• Contributing Catchment area;

• Retention volume of structure(s);

• Shape of structure(s);

• Position of inlets/outlets;

• Stabilisation of the structure;

• Confirmation of compliance with consent condition; and

• Size of diversions(s) and method of stabilisation.

6.1.5 A copy of the “as-built” erosion and sediment control plans shall be kept on site, and all erosion and sediment control measures including staging boundaries and particularly the extent of exposed areas shall be updated immediately as changes are made. As-built plans shall be accompanied by text detailing the relevant earthworks methodology, constraints and likely progressions and shall be revised as required to enable clear interpretation as to the day to day operation and management of erosion and sediment controls.

6.1.6 No sediment retention ponds are to be removed unless approved by the ARC.

6.1.7 Any fill areas including temporary embankments and disposal sites are to be constructed to a standard that ensures structural integrity of the fill.

6.1.8 The Consent Holder shall ensure that the following earthworks shall be stabilised as soon as practicable after completion thereof or within 5 days of completion whichever shall occur first:

• Cut and fill batters over the length of each cut and fill;

• 200 metre lengths of prepared subgrade over the formation width;

• Contractors site establishment and storage areas; and

• The Consent Holder shall stabilise any other area which is not being actively worked within fourteen days of the last earthworking activity within the area, or within such further period as is agreed with the ARC from time to time as circumstances warrant.

6.1.9 All cut and fill grades (excluding batter slopes and haul roads) shall be constructed to provide a gradient of no greater than 1 in 4 throughout the project, until the earthworks reach final grade.



6.1.10 Prior to the commencement of bulk earthworks the Consent Holder shall arrange for a field exercise in the practical application of TP90, and consent conditions for all contractors staff involved in erosion and sediment control, including supervisors.

6.1.11 Temporary Sediment Control

Temporary sediment control is the second phase of limiting sediment yield from an earthworks site, the first, and most critical, being erosion control. Sediment control usually entails sediment ponds, but can also include silt fences, vegetated buffer strips, and bunding, or combinations of these depending on the nature of the site. In other words, sediment control is the means of trapping sediment on the site once it has been eroded.

It should be noted that the ARC TP90 (1999), which provides guidelines for land disturbing activities, does not require that a certain percentage sediment reduction occur for temporary sediment control. This is a requirement of long-term stormwater quality improvement devices only. Design and specifications for temporary stormwater treatment devices shall comply with and reference the TP90 and the Regional Plan: Sediment Control.

6.2 Permanent Stormwater Management

6.2.1 Stormwater management and treatment devices shall be designed in accordance with regional best practice including:

• the Guidelines for Stormwater Runoff Modelling in the Auckland Region (ARC TP108, 1999), and

• ARC TP10.

Design Standard

6.2.2 The final design and specifications of the stormwater system shall be submitted to the ARC for written approval prior to the commencement of construction works. The specification shall include but not be limited to the following:

• treatment efficiency calculations;

• flow attenuation calculations;

• design drawings;

• catchment plans detailing the area draining to each device;

• outfall locations; and

• outfall design drawings.



Any amendments to these designs shall be approved in writing by the ARC prior to implementation.

6.2.3 The Consent Holder shall ensure that the stormwater system approved above is constructed and operational prior to the alignment being opened to public traffic flows.

6.2.4 The stormwater from each discharge point shall be treated by devices designed to remove at least 75% of total suspended solids from stormwater runoff collected by the stormwater system on a long term average basis from new impervious surfaces as best practicable within the Project area. The design efficiencies shall be evaluated in accordance with guidelines given in the TP10.

6.2.5 The Consent Holder shall ensure that all stormwater treatment devices are designed in accordance with Regional best practice.

6.2.6 The Consent Holder shall ensure that outfalls are of such location, design and performance as to minimise erosion of any waterway or adjacent marine environment.

As-Built Condition

6.2.7 The Consent Holder shall supply to the ARC, within 60 days of the completion of the Project, “as built” plans of the stormwater system. These “as built” plans shall include but not be limited to:

• The surveyed locations and elevations of all outfall structures, which shall be measured to the nearest 0.1 m with co-ordinates expressed in terms of the New Zealand Map Grid and DOSLI datum;

• Stormwater management device details including locations, dimensions, levels, volumes, flood levels, sections, treatment efficiencies, inlet and outlet structures;

• Photographs at all outfall locations showing the stream channel condition at the outlet, upstream and down steam of the outlet, as a means of documenting the existing stream condition in the location of the outfall;

• Vegetation documentation to show areas of vegetation cleared for stormwater devices and areas of re-vegetation and areas of vegetation protected;

• Documentation of any discrepancies between the design plans and the “as built’ plans.

Maintenance



6.2.8 The Consent Holder shall ensure that all outfalls are maintained in such a manner as to minimise erosion occurring in the areas adjacent to the outfall.

6.2.9 An Operation and Maintenance Plan for the stormwater system shall be submitted to the ARC for written approval within 6 months of the completion of project construction.

The plan shall include, but not be limited to, operation and maintenance requirements including the following:

• post storm maintenance;

• outfall structure maintenance;

• frequency of regular maintenance inspections;

• inspection procedures;

• vegetation assessment criteria;

• maintenance evaluation criteria;

• sediment measuring methods and

• inspection checklists for all aspects of the system.

6.2.10 The Consent Holder shall manage the stormwater system in accordance with the operation and maintenance plan that has been approved in writing by the ARC.

6.2.11 Where treatment in accordance with 6.2.4 is not practicable, this shall be discussed with the ARC and an alternative approach agreed.

6.2.12 Flexibility in the type of device is encouraged to enable the most efficient device for a given locality to be selected. However the following overall approach is recommended wherever practicable:

• Discharges shall be treated using swales where appropriate;

• Where swales are not practicable, treatment devices and maintenance access shall minimise impacts upon native vegetation and the CMA;

• The selection of treatment devices shall have regard for the impact of long term maintenance upon live traffic lanes, therefore devices should be selected in consultation with the Transit Network Managers; and

• Stormwater treatment ponds shall incorporate wetland planting where this is appropriate and shall marry in with the existing landscape and revegetation programme.



6.3 Works Within the CMA

Works along and within the CMA will include a range of activities including reclamation, bridge construction and piled structures. The general principles for works within the CMA are set out below, these proposed measures are dependant upon the form of the structures selected:

6.3.1 For the duration of the proposed construction works, the Consent Holder shall maintain the site and remedy any damage and disturbance caused to the foreshore by vehicle traffic, plant and equipment used in construction of the proposal.

6.3.2 The access areas shall be constructed and located so as to minimise the impact on saline vegetation where practicable.

6.3.3 Prior to the works taking place, aerial photographs should be taken in the area of the proposed works and upstream from these. Two sets of photographs are to be taken within a twenty day period, one showing high tide and one showing low tide. The precise dates and times of the photographs shall be noted.

6.3.4 Any works within or adjacent to the CMA likely to generate suspended sediment shall be monitored for the spread of sediment. Visual detection of widespread additional turbidity more than 200m outside the construction area will be a trigger point for the temporary cessation of work or for changing to better work practices. These include in addition to normal best work practice; carrying out the most disturbing work at lower tide levels on the drying mudflats.

6.3.5 Within 6 months of completion of the works, or such longer time as approved by the ARC, the Consent Holder shall remove any temporary structures, equipment and material and reinstate the foreshore and seabed,

6.3.6 In order to mitigate any adverse visual effects of the bridge structures, the Consent Holder shall submit detailed plans showing all reinstatement planting in accordance with the landscape plan prepared by Opus International Consultants contained in Volume 2 Technical Appendix 9, Landscape and Visual Assessment.

6.3.7 For the duration of the proposed construction works, the Consent Holder shall maintain the site to remedy any damage and disturbance caused by vehicle traffic plant and equipment to the foreshore and seabed.

6.3.8 The Consent Holder shall ensure that any temporary reclamation is constructed using only inert cleanfill.



6.3.9 The Consent Holder shall as far as practicable, construct and locate any temporary reclamation in such a manner so as to minimise the area of the reclamations.

6.3.10 The Consent Holder shall as far as is practicable, design any temporary reclamation, works or structures so as to minimise the effects on the hydrology of the area.

6.3.11 Within 6 months of the completion of the Duplicate Bridge structure and the Orpheus Drive reclamation, or such longer time as approved by the ARC, the Consent Holder shall remove any temporary reclamations, structures, equipment and temporary material and reinstate the foreshore and seabed.

6.3.12 The EMG shall include the following details with regard to heavy rainfall events:

• The criteria to be used to determine what a heavy rainfall is and when heavy rainfall events capable of causing unacceptable adverse impacts are occurring;

• The specific monitoring to be undertaken during such heavy rainfall events; and

• Details of possible actions that shall be undertaken if unacceptable adverse impacts occur.

6.3.13 As part of the EMG, the Consent Holder shall also include an environmental monitoring program prepared by a suitably qualified and experienced environmental scientist. The environmental monitoring program shall include, but not be limited to the following:

• Monitoring macroinvertebrates in the Mangere Inlet at each end of the Duplicate Bridge on one occasion each year in late summer. The protocol for macroinvertebrate sampling shall be established by a suitably qualified and experienced biologist;

• Identification of environmentally acceptable trigger levels in relation to turbidity, sediment deposition and effects on macroinvertebrates. Contingency measures, are to be undertaken when such trigger levels are exceeded; and

• Reporting procedures.

6.3.14 The EMG shall specify action to be taken should any of the trigger levels specified in the EMG be reached. Provisions in this regard shall include, but are not limited to the following:



• A process for notification and consultation with the Manager and any other agreed parties to determine what remedial action or alteration of operations is appropriate in the event trigger levels are exceeded; and

• A verification process (i.e. more intensive monitoring) to determine whether remedial action has remedied or mitigated the detected effects.

6.3.15 Monitoring specified in the EMG shall be undertaken for a period in accordance with the likely time horizons of the specific effect being monitored and monitoring periods shall be specified in the EMG. The maximum time period for monitoring as specified in the EMG will be no more than three years following the opening of the Project.

6.4 Survey

Survey is likely to occur in advance of either the main construction or enabling works. There are limited areas where the clearance of vegetation will be an issue during surveying and setting out. Nevertheless, care must be exercised to ensure that vegetation clearance is kept to a minimum to ensure areas are not cleared unnecessarily.

The following shall apply to any survey works:

6.4.1 No unnecessary branch trimming, tree felling or other environmental disturbance shall occur beyond what is absolutely necessary to establish the line of sight for alignment survey or to gain reasonable access from areas outside the designated alignment corridor.

6.4.2 Any clearance of vegetation shall ensure vegetation is felled to minimise damage to any vegetation surrounding the carriageway.

6.4.3 There shall be no clearance of vegetation including mangroves within the coastal marine area for survey purposes except where approval from the ARC has been obtained prior to undertaking the survey.

6.4.4 Any vegetation removed with ARC approval from the coastal marine area shall be kept to the absolute minimum required and vegetation trimmings shall be removed for appropriate off site disposal.

6.4.5 Surveyors working within the CMA shall take care not to tread on mangroves and create unnecessary disturbance. Where possible the surveying team shall use the same access tracks to minimise damage.

6.4.6 Any further clearing of vegetation should only proceed when construction is imminent.



6.5 Site Investigations

Site investigations will primarily relate to geotechnical investigations, however for this Project these will also need to incorporate environmental sampling for soil contaminants (refer Section 5.4). These investigations are likely to be required throughout the route, including within the coastal marine area.

The following shall apply to all site investigations works:

6.5.1 Environmental investigations for soil contamination should occur concurrently with any geotechnical investigations wherever practicable to minimise disturbance. When environmental samples are to be taken no drilling fluids are to be used during the drilling to reduce the risk of cross contamination between samples. Furthermore, environmental samples shall be collected using a split spoon to obtain undisturbed cores (refer also Section 5.4).

6.5.2 A permit to install, make, or alter a bore shall be sought and obtained if necessary from the ARC prior to commencement of any geotechnical investigations or bore establishment.

6.5.3 No unnecessary environmental disturbance (including unnecessary tree felling) shall occur beyond what is absolutely necessary to establish boreholes or to gain reasonable access from areas outside the designated alignment corridor.

6.5.4 All site investigations shall comply with any other relevant sections within this document including the archaeological guidelines.

6.5.5 Erosion and sediment controls shall be implemented, particularly on steep embankments and adjacent to any watercourse for any site investigation works. The area shall be temporarily stabilised (e.g. using straw) over the interim period before construction commences.

6.5.6 All equipment and structures are to be removed from the site immediately upon completion of the investigation.

6.5.7 Where drilling fluids are used, all fluids and mud shall be collected and appropriately disposed of off site; and

6.5.8 If slope dewatering is required, or other activities are to be undertaken that require the diversion and/or discharge of groundwater, then a permit shall be obtained if necessary from the ARC prior to commencement of that activity. This includes any temporary or permanent slope dewatering.

6.6 Stockpiles

Although there is limited area for these, stockpiles of top soil, clean-fill, engineering unsuitables, and roading aggregates are likely to be needed throughout the course of the



project. All have the potential to generate silt and to possibly discharge other contaminants (e.g. nutrients). To mitigate the potential for erosion, stockpiles will be subjected to controls such as are set out below.

The following requirements shall apply to stockpiles:

6.6.1 All materials used on the site shall be Cleanfill. Cleanfill is as defined within the Glossary (refer also Section 5.4).

6.6.2 All stockpiles are subject to the erosion and sediment control requirements contained within Section 6.1 of this Plan.

6.6.3 Damage to the surrounding environment as a result of stockpiling activities shall be minimised.

6.6.4 All residual material shall be removed and the environment appropriately re-instated upon cessation of stockpiling.

6.6.5 Clean water flows shall be diverted around stockpiles (or under using culverts) located within areas subject to overland flow.

6.6.6 Stockpiles shall be located within the alignment wherever practicable; and

6.6.7 Contaminated materials and materials from which the release of free liquids is likely (e.g. from marine sediments) shall not be stockpiled on site and shall be loaded directly on to trucks for removal from site.

6.7 Refuelling/Maintenance Areas

Refuelling and maintenance activities have the potential to release oil, diesel, degreasers and other contaminants into the environment. The restrictions proposed recognise the areas of ecological sensitivity together with the practical implications of removing vehicles from an area for refuelling.

There will be situations that may not be able to be controlled, such as the rupture of a hydraulic fuel line. Mitigation measures are required so that the effect of such incidents are minimised and mitigated wherever possible. A specific response plan is required to be included within the CEMP.

6.8 Site Facilities

Site facilities such as ‘smoko sheds’, ablution blocks (toilets etc.), and offices that act as the control centre for each area of the project, and have potential to generate heavy levels of non-construction related traffic movements, dust, litter etc which may result in adverse environmental effects.

Requirements for site facilities are as follows:



6.8.1 Covered rubbish bins are to be provided and the refuse regularly and as required to ensure that wastes do not overtop the bins appropriately disposed of off site.

6.8.2 Waste bins for the collection of non-construction related wastes shall be covered to minimise wind blown debris.

6.8.3 Bins for the collection of cans, glass, and plastic are to be provided for recycling and are located next to any site amenities.

6.8.4 The construction and operation of site offices, amenity buildings and site facilities are prohibited within 10m of a Category 1 watercourse or the CMA; and

6.8.5 Sanitary wastes will be collected and disposed of off site in an appropriate manner. If retention tanks are to be used, these shall be cleaned out regularly to prevent overflows. Portable units shall be protected from traffic movement and will not be located within 10m of a watercourse or over the coastal marine area.

6.9 Dust Control

Dust can affect vegetation health along the edge of the earthworks area, can be a nuisance to the surrounding public, and can contribute to sediment loads by depositing in areas without sediment control measures. Sediments deposited on sealed public roads can also result in a dust nuisance.

Dust control requirements are:

6.9.1 Hydrocarbons (such as hydraulic oils) shall not be used as a method of controlling dust.

6.9.2 A dust control strategy shall be developed prior to commencement of the Project to assess such things as the:

• Volume of water that is likely to be required;

• Number of watering trucks required; and

• Location and number of wheel washing facilities; and

• Proposed sweeping regime (Note that tractor mounted sweepers require dust suppression attachments to be utilised).

6.9.3 Vehicles that have used unsealed areas of the site shall be required to wash the wheels of their vehicles prior to leaving the site onto sealed public roads (this may be a high pressure water blast or an appropriately constructed water bath). This shall be noted and advised to any persons visiting the site so that this time can be factored into travelling time (e.g. for the delivery of loads).



6.9.4 The water from the wheel wash shall be treated to remove sediment and shall also incorporate mechanisms such as baffles to trap hydrocarbons (released from the wheel); therefore detergents shall not be used in wheel washes. By ensuring sediment is removed from the wheels of vehicles, sediment will be restricted to the site and not create either a dust or a sediment nuisance on public roads.

6.9.5 The abstraction of ground or surface waters (i.e. from watercourses) shall not occur.

6.10 Dewatering

Dewatering may occur as a result of pile construction where water seeps into pile cap shuttering. Dewatering has the potential to release sludge from within the pile cap casing. Therefore particular care needs to be taken to ensure appropriate dewatering techniques are used.

Prior to the commencement of any dewatering procedure, a dewatering methodology shall be developed and included within the CEMP.

6.11 Sealing

Sealing of the road surface has the potential to release emulsions, other bituminous compounds, and particularly semi-volatile organic compounds such as diesel and kerosene. These compounds can impact significantly upon the environment, especially if released into a sensitive intertidal environment.

6.11.1 Any road surfacing materials stored on site shall comply with the other site restrictions.

6.11.2 The mixing and testing of batches and tank cleaning is not to occur on site. Any wastes shall be appropriately contained and disposed of off site.

6.11.3 Any contaminated materials shall be cleaned up immediately, removed from site and disposed of appropriately.

6.11.4 All spills are to be recorded within the CEMP. Spills over 60L and spills of any volume to a watercourse, are to be reported immediately to the Engineer and the ARC together with remedial measures taken.

6.11.5 A spill containment kit shall be carried at all times. The kit is to contain sawdust (or another suitable adsorbent), gloves, a spare absorbent boom, and a container for the disposal of contaminated equipment and soils (Large spills will require appropriate arrangements to be made for removal and disposal).

6.11.6 Geotextile will be placed across stormwater grates during all sealing operations in accordance with Transit requirements.



6.11.7 Detergents shall not be used to disperse spills of hydrocarbons, unless required by the ARC.

6.12 Installation of Services

Any installation of services shall be subject to the same level of controls as the road construction whether carried out as part of the original construction or carried out during the operational phase. This is to ensure that any environmental mitigation is not undone at a later date by sediment released from trenching along the roadway.

Sediment deposited within long-term stormwater quality improvement devices during installation of services shall be removed and disposed of appropriately. Bare earth shall be kept to a minimum and revegetated/sealed as soon as possible. The affected areas shall be reinstated to the same standard as they were encountered.

6.13 Weed Control

Weed control will arise as both a short term and long term issue.

The following general requirements apply:

6.13.1 All weed controls and herbicide applications shall comply with General Authorisation 25 of the Transitional Regional Plan.

6.13.2 Any clippings and debris created as a result of ‘mowing’ within 10m of a watercourse shall be collected immediately to ensure the organic material is not washed into the watercourse and

6.13.3 Weed control maintenance shall be minimised through planting regimes.

6.14 Noise and Vibration

The Project will create changes to the existing noise environment both during construction and as a completed roadway.

6.14.1 During construction, the Contractor shall where practicable comply with New Zealand Standard 6803P: 1984 The Measurement and Assessment of Noise from Construction, Maintenance and Demolition Work.

6.14.2 The Contractor shall prepare a Construction Noise Management Plan (CNMP) to demonstrate how requirement 6.14.1 will be implemented, monitored, and identify contingency measures that are available should this not be achieved. This plan shall be drafted in accordance with the CNMP and any conditions of the designation.



6.14.3 Long-term noise and vibration shall comply with the relevant Transit standards and the appropriate requirements as set out in the conditions of the designation.

6.14.4 Noise amelioration shall be integrated with the surrounding landscape.

6.14.5 Long-term noise levels are to be verified within six months of the Project becoming operative.

SH20 Manukau Harbour Crossing - Assessment of ... · Note 1 Proposed form of interchange revised...

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