COLOMBO -BECKENHAM WASTEWATER

PIPELINE RESOURCE CONSENT APPLICATION & ASSESSMENT OF EFFECTS ON THE ENVIRONMENT

Prepared for Christchurch City Council

December 2016

Colombo-Beckenham Wastewater Upgrade

This document has been prepared for the benefit of the Christchurch City Council. No liability is accepted by this company or any employee or sub-consultant of this company with respect to its use by any other person.

This disclaimer shall apply notwithstanding that the report may be made available to other persons for an application for permission or approval to fulfil a legal requirement.

QUALITY STATEMENT

PROJECT MANAGER PROJECT TECHNICAL LEAD Chris Maguire Stephanie Thompson

PREPARED BY Megan Couture ………………………………..... 19/12/2016 CHECKED BY Janan Dunning …… …...... 21/12/2016 REVIEWED BY Janan Dunning …… …...... 21/12/2016 APPROVED FOR ISSUE BY

Chris Maguire …… ……...... 21/12/2016

CHRISTCHURCH Hazeldean Business Park, 6 Hazeldean , Addington, Christchurch 8024 PO Box 13-052, Armagh, Christchurch 8141 TEL +64 3 366 7449, FAX +64 3 366 7780

REVISION SCHEDULE

Signature or Typed Name (documentation on file) Rev Date Description No. Prepared by Checked by Reviewed by Approved by 1 12/12/16 Draft for Review MC JD JD ST 2 21/12/16 Final for Lodgement CM

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Resource Management Act – Form 9 Application for Resource Consent Section 88, Resource Management Act 1991

To: Christchurch City Council PO Box 73014 Christchurch 8154

From: Christchurch City Council PO Box 73014 Christchurch 8154

The Christchurch City Council applies for the following resource consent: i) Land Use Consent The activity to which the application relates:

 The Project involves the duplication of wastewater pipes along Colombo Street (between Dyers Pass Road and Fisher Avenue) and the installation of new wastewater pipes along the length of Beckenham Street, and across the Heathcote River.  Consent as a restricted discretionary activity is required for excavation in a Coastal Confined Aquifer of more than 100m3 and within 50m of a river. The proposed activity is to occur in within Christchurch City at: a) The Project is located within parts of Colombo Street, from the intersection of Colombo, Centaurus and Dyers Pass Road, along the length of Beckenham Street, and below the Heathcote River; b) The Project is primarily located within the road reserve. The Heathcote River intersects the Project between Hunter and Waimea . A full description of the site is provided in Section 3 of this application. The other activities to which this application relates:

 Construction related discharges;  The taking of groundwater for the purpose of dewatering;

 Disturbance under the bed of a river and the installation of pipes;  Temporary discharges to water or land; and  outside the bed of a river, within 5m of the bed of a river.

A description of how these activities meet the permitted activity standards is contained in Appendix B to this application. No additional resource consents are needed for the proposal to which this application relates. Attached is an assessment of the proposed activity’s effect on the environment that —

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a) Includes the information required by clause 6 of Schedule 4 of the Resource Management Act 1991; and b) Addresses the matters specified in clause 7 of Schedule 4 of the Resource Management Act 1991; and c) Includes such detail as corresponds with the scale and significance of the effects that the activity may have on the environment. Attached is an assessment of the proposed activity against the matters set out in Part 2 of the Resource Management Act 1991. Attached is an assessment of the proposed activity against the relevant provisions of a document referred to in section 104(1)(b) of the Resource Management Act 1991, including the information required by clause 2(2) of Schedule 4 of that Act. A full description of the proposal and the actual and potential environmental effects is contained in the attached document which forms part of this application. No further information is required to be included in this application by the district plan, the Resource Management Act 1991, or any regulations made under that Act.

pp………………………………….. Colin Currie Christchurch City Council Tel: +64 3 941 548y Email: [email protected]

Address for service of the application: MWH Global (now part of Stantec)

Attn: Janan Dunning PO Box 13 052 Christchurch 8024 Tel: +64 3 341 4790 Mob: +64 27 600 8432 Email: [email protected]

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Christchurch City Council Colombo-Beckenham Wastewater Upgrade

CONTENTS 1 Introduction ...... 1 2 Proposal ...... 2 2.1 Existing Issues and Proposed Solution ...... 2 2.2 Project Description ...... 2 2.3 Construction Methodologies ...... 3 2.3.1 Open trenching ...... 3 2.3.2 Trenchless technologies ...... 4 2.3.3 Site dewatering ...... 4 2.3.4 Erosion and sediment control ...... 4 2.4 Resource Consents Required ...... 4 3 Site Description ...... 6 3.1 Overview ...... 6 3.2 Zoning and Notations ...... 7 3.3 and Groundwater ...... 7 4 Assessment of Effects on the Environment ...... 8 4.1 Positive Effects ...... 8 4.2 Groundwater Effects ...... 8 4.2.1 Overview ...... 8 4.2.2 Mitigation ...... 8 4.3 Effects on the Heathcote River ...... 9 4.3.1 Overview ...... 9 4.3.2 Mitigation ...... 9 4.4 Effects on Potentially Contaminated Land ...... 9 4.4.1 Overview ...... 9 4.4.2 Mitigation ...... 9 5 Consultation ...... 11 6 Statutory assessment ...... 12 6.1 Overview ...... 12 6.2 National Policy Statement for Freshwater Management ...... 12 6.3 National Environmental Standard for Assessing and Managing Contaminants in to Protect Human Health ...... 12 6.4 Canterbury Regional Policy Statement ...... 13 6.5 Canterbury Land and Water Regional Plan 2015 ...... 15

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6.6 Other Matters ...... 16 6.6.1 Heritage New Zealand Pouhere Taonga Act ...... 16 6.6.2 Mahaanui Iwi Management Plan 2013 ...... 16 6.6.3 Utilities Access Act 2010 ...... 16 7 Part 2 Assessment – Purpose and Principles ...... 17 8 Conclusion ...... 19

LIST OF TABLES Table 2-1: Resource consents sought by the Christchurch City Council ...... 4 Table 6-1: Relevant Provisions (NPS) ...... 12 Table 6-2: Relevant Provisions (CRPS) ...... 13 Table 6-3: Matters of Discretion (CLWRP)...... 15 Table 7-1: Part 2 Assessment ...... 17

LIST OF FIGURES Figure 2-1: Proposed Colombo Street Alignment ...... 2 Figure 2-2: Heathcote River Crossing ...... 3 Figure 3-1: Site Location: Colombo & Beckenham Streets ...... 6

APPENDICES Appendix A Geotechnical Assessment Appendix B Permitted Activities Assessment

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1 Introduction

Christchurch City Council (the CCC) is seeking resource consent for the installation of wastewater pipes within the Colombo-Beckenham area to increase capacity in the wastewater network, and to reduce the potential for overflows stemming from capacity constraints. This proposal involves the duplication of wastewater pipes along Colombo Street (between Dyers Pass Road and Fisher Avenue) and the installation of new wastewater pipes along the length of Beckenham Street, and across the Heathcote River (“the Project”). The Project requires consent as a restricted discretionary activity under the Canterbury Land and Water Regional Plan. This Assessment of Effects on the Environment (AEE) and the resource consent application identified in this report relate to the works being undertaken for the Project, and has been prepared in accordance with Section 88 of the Resource Management Act (1991). An overview of the proposal is provided below, and Section 4 provides an assessment of the actual and potential effects on the environment, as required by the Fourth Schedule of the RMA.

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2 Proposal

2.1 Existing Issues and Proposed Solution

The Project involves the duplication of a section of the wastewater main along a segment of Colombo Street, and the installation of a cross-connection along the length of Beckenham Street. The primary objective of this project is to implement improvements to address the wastewater overflows from the PS20 catchment during the 3-year Average Recurrence Interval (ARI), 24 Hour Duration Storm, and to increase capacity in the existing network. Modelling undertaken indicates that the Project will lower surcharging levels in the existing network and alleviate flooding issues that have been experienced in the area, and will increase levels of service.

Figure 2-1: Proposed Colombo Street Alignment 2.2 Project Description

The Project begins from the intersection of Colombo, Centaurus and Dyers Pass , moving northwards for approximately 1km, before it terminates at the intersection of Colombo Street and Fisher Avenue (Figure 1). The Heathcote River intersects this section of the Project between Hunter and Waimea Terrace. At this location, the alignment exits Colombo Street onto Hunter Terrace where it then crosses beneath the Heathcote River towards Waimea Terrace to the east of the Heathcote River Bridge. The crossing of the Heathcote River (and subsequent deviation outside of the road reserve) was necessary as the bridge was not designed to accommodate the additional weight of the pipeline (either beneath or attached to the bridge).

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Figure 2-2: Heathcote River Crossing Once the Heathcote River has been crossed, the Project continues along Colombo Street until reaching the intersection of Colombo Street and Fisher Avenue. It then resumes at Beckenham Street, where it will be installed along the length of the street within the carriageway (approx. 200m). Based on the concept design to date, the proposed nominal diameters (DN) and materials associated with the pipeline are as follows:  130m of DN225 PVC-U pipe on Colombo Street  320m of DN475 PVC-U pipe on Colombo Street  575m of DN600 PVC-U pipe on Colombo Street  220m of DN600 PVC-U pipe on Beckenham Street  30m of DN560 PE100 pipe for the Inverted Siphon on Colombo Street 2.3 Construction Methodologies

2.3.1 Open trenching As the Project is almost exclusively within the road reserve, the majority of the Project will be constructed by conventional open trenching methods, which is routinely undertaken for pipeline projects in Christchurch and New Zealand more generally. The will be excavated to a depth of between 4-5m, with a width of approximately 2m. The trenching will be undertaken in 10m sections, in accordance with Christchurch City Council limits. Entire work areas are expected to be no more than 120m long for any construction site, to include approach areas for distance and setbacks required for traffic management at either end of the wor k area. These areas are to be limited to 10m when offsite. Excavated material will be either used for backfill or disposed off-site (depending on material properties). If the excavated material is disposed off-site, the trench will be backfilled with approved granular material. Localised connections to property boundaries will be required between Wherstead Road and Malcolm Avenue.

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2.3.2 Trenchless technologies To install the pipeline beneath the bed of the Heathcote River, trenchless technologies will be used. Typical trenchless technologies include:  Horizontal Directional Drilling (HDD): a steerable trenchless method of installing underground pipes in a shallow arc along a prescribed bore path using a surface launched drilling rig;  Microtunneling: a trenchless technology that involves the use of a boring machine to create a tunnel. The tunnel boring machine is then ‘pushed’ through the hole by the pipes; and  Pipe ramming: a trenchless method for the installation of pipes by pneumatic blows or thrusts to drive the pipe forward through the ground. These methods will require the establishment of a site compound on either side of the Heathcote River within Hunter and Waimea Terraces, which will include drilling rigs, excavation equipment and other associated plant. This will also require the installation of tunnel “pits” to send/receive the drilling equipment, of approximately 4m x 10m x 5m deep. The sites to construct the entry and exit pits will be set up in the road reserve outside the riverbank margin, on either side of the Heathcote River (Hunter and Waimea Terraces). This will avoid the need to clear any vegetation or trees. The pipeline will be installed beneath the bed of the Heathcote River at a depth of between 2 – 4.5m below ground level. Once completed, all machinery and temporary facilities associated with the pipeline installation will be removed. 2.3.3 Site dewatering Given the high water table, excavations will extend below the anticipated groundwater level for the site. As such, dewatering of the trench will be required during construction activities. Dewatering will occur along the length of the pipe trench and in the excavated pits for installing the pipeline under the Heathcote River bed. The CCC hold permits to take and discharge groundwater for site dewatering purposes. 1 Groundwater that is encountered from dewatering activities will be discharged in accordance with the conditions of these consents, and diverted into the CCC’s reticulated stormwater system. 2.3.4 Erosion and sediment control Total earthworks volumes (material to be excavated) are estimated to be approximately 3,500m3. Erosion and sediment control measures in accordance with Environment Canterbury’s Erosion and Sediment Control Guideline 2007 will be implemented along the length of the Project during all land disturbance works to prevent the discharge of sediment and sediment-laden water to nearby waterbodies and the stormwater system. 2.4 Resource Consents Required

The following table is a summary of the activities requiring resource consent for the Project: Table 2-1: Resource consents sought by the Christchurch City Council Canterbury Land Permit Activity and Water Activity Status type Regional Plan

Excavation in a Coastal Confined Aquifer of Land use Rule 5.176 Restricted discretionary more than 100m3 and within 50m of a river.

1 Consent No. CRC121311 and CRC121310

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Rule 5.175(1) of the Canterbury Land and Water Regional Plan (LWRP) states that the use of land to excavate material over areas identified as a Coastal Confined Aquifer System is a permitted activity, subject to the following conditions: a) there is more than 1m of undisturbed material between the deepest part of the excavation and Aquifer 1; and b) if more than 100 m3 of material is excavated, the excavation does not occur within 50m of any surface waterbody; As excavations will exceed 100m3 and will occur within 50m of the Heathcote River, Rule 5.175(1)(b) cannot be met. Rule 5.176 states that the use of land to excavate material that does not comply with one or more of the conditions of Rule 5.175 will require consent as a restricted discretionary activity.

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3 Site Description

3.1 Overview

The Project is located within parts of Colombo Street, from the intersection of Colombo, Centaurus and Dyers Pass Road, and along the length of Beckenham Street (Figure 1).

Figure 3-1: Site Location: Colombo & Beckenham Streets Colombo Street is a minor arterial road, runs in a north-south direction, and is 20m wide along the length of the Project. It includes a single carriageway in each direction, plus bus lane and footpath. Trees of various size are present adjacent to the road reserve boundary along the proposed alignment. The land use surrounding the alignment is predominately residential, with some small businesses, educational and community facilities along Colombo Street in the vicinity of the proposed works. Beckenham Street is 15m wide, and contains a single carriageway in each direction, with on-street parking and a footpath on both sides. Beckenham Street also runs in a north-south direction. The land use along Beckenham Street is residential and there are trees of various sizes adjacent to the road reserve boundary along the project alignment. The Heathcote River intersects this section of the Project between Hunter and Waimea Terrace. The river at Colombo Street is considered a ‘non-tidal reach’ in the Canterbury Geotechnical

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Database. At the location of the proposed river crossing (described in detail below), the banks of the river are up to approximately 2m high, and slope at up to approximately 45°. The river channel is approximately 8m wide. Cabbage trees and flax are located on the banks of the Heathcote River, along Waimea Terrace and Hunter Terrace. The bed and banks of river have high potential for archaeological discovery due to the connection with mana whenua to waterways and also the likely pre-1900 European use of waterways. Although no recorded sites have been identified, the SCIRT GIS database identifies the bed and banks of the Heathcote River to be a high risk site for archaeological values. Some large trees are present at the corner of Hunter Terrace and Colombo Street, within the South Christchurch Library site. Hunter Terrace is present on the southern side of the river, with South Christchurch Library beyond that (i.e. greater than 20m from the river bank). Waimea Terrace is on the northern side of the river, lined with residential dwellings. 3.2 Zoning and Notations

The following notations from the LWRP are considered to be relevant to the Project:  Aquifer: Coastal Confined Gravel Aquifer System (Map B-C12)  Groundwater allocation zone: Christchurch/West Melton Groundwater Allocation Zone (Map B- C12)  Groundwater protection zone: Christchurch Groundwater Protection Zone, Ernlea Terrace to Malcom Avenue (Map A-C12)  Water bodies: Heathcote River (Springfed – Plains Urban) (Map A-C12) 3.3 Geology and Groundwater

A desktop study of existing geological and geotechnical conditions has been carried out based on ground investigation data contained with the Canterbury Geotechnical Database (CGD). Anticipated conditions are predominately silty and sandy , ‘very loose’ to ‘loose’ density with possible layers of interbedded clays and sandy . Median groundwater levels vary across the project area, but are typically 2.0m to 4.0m below ground level, falling towards the Heathcote River. Environment Canterbury (ECan) logs indicate that the confined aquifer, in the Riccarton Gravel, is at depths of approximately 20 to 25m bgl in the vicinity of the project area.

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4 Assessment of Effects on the Environment

4.1 Positive Effects

The Project will address the issues identified in Section 3.1 above, and once completed the Project will facilitate the continued effective operation of the wastewater network generally, reduce the potential for overflows and provide capacity in the wastewater network for future growth and development. This will in turn:  Enable the CCC to meet level of service requirements;  Reduce overflows and minimise potentially harmful pathogens reaching freshwater environments;  Replace a small section of damaged pipe between Malcolm Avenue and Wherstead Road;  Minimise the potential for adverse amenity effects on public areas and recreation values; and  Assist in the restoration of the mauri of waterways. 4.2 Groundwater Effects

4.2.1 Overview In general terms, the potential effects that are relevant in relation to land settlement and groundwater levels are:

 Surface settlement arising from the construction of the pipeline (mechanical settlement); and  Groundwater lowering (drawdown) that might occur during construction, or persist after construction is complete. Groundwater drawdown may also cause surface settlement (groundwater drawdown settlement). Appendix A provides a summary of the geotechnical assessment untaken for the proposed works, and identifies the potential risks associated with dewatering and groundwater drawdown. The report notes that:  Groundwater is expected to be encountered during construction, and is likely to be up to approximately 1.0m above proposed trench inverts.  Existing structures are set back a minimum distance of approximately 10m from the centreline of the proposed trench;  There are no known high importance level or particularly sensitive (or their contents) structures along the alignment;  There is no evidence in the existing ground investigation for highly compressible (e.g. ) 4.2.2 Mitigation The Technical Report contained in Appendix A notes that construction will be easier if undertaken when groundwater levels are at their seasonal lowest. This will help reduce the risk associated with excavation instability and preparation, excavation dewatering and groundwater drawdown induced settlement. On this basis, construction works are proposed to be undertaken during late summer / early autumn, when groundwater levels are typically at their lowest. Furthermore, minimum requirements for construction should be documented in the Construction Specifications and should include pre and post construction condition inspections.

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Based on the above, the report concludes that the risks associated with dewatering and groundwater drawdown induced settlement can be managed by the use of appropriate construction practices. The risk are considered ‘typical’ for Christchurch dig and lay construction (i.e. no unusual site specific considerations). 4.3 Effects on the Heathcote River

4.3.1 Overview Trenchless technologies are unlikely to result in adverse effects on the Heathcote River, as it avoids disturbance of the riverbed. However, to facilitate the installation of the pipeline beneath the river, construction sites will need to be set up outside the river bank. Due to the proximity of these sites to the Heathcote River, there is the potential for sediment from construction activities and sites to ente r into the river. 4.3.2 Mitigation To mitigate potential adverse effects that may arise from construction activities, an Erosion and Sediment Control Plan will be implemented in accordance with the Erosion and Sediment Control Guideline 2007, to prevent the discharge of sediment and sediment-laden water to the Heathcote River. 4.4 Effects on Potentially Contaminated Land

4.4.1 Overview During recent drilling adjacent to the Heathcote River, the potential presence of uncontrolled fill within the top 2.6m of the southern bank and the top 1.5m of the northern bank was encountered, which is indicative of potentially contaminated soil. Samples from these areas were subsequently analysed for the heavy metals suite (As, Cd, Cr, Cu, Pb, Ni, Zn) and for SVOCs at screening level, with the results finding elevated levels of lead (1,840mg/kg) at one of the sites (with the other site testing at background levels in Canterbury Soils). In addition to the above, it is understood that at 25 Colombo Street (Z Cashmere) a dissolve d phase petroleum hydrocarbon plume is migrating off-site. The contamination does not appear to be migrating across Colombo Street where the proposed works will be undertaken, but possible migration along services bedding has not be adequately investigated and therefore the identification of possible receptors and the associated risks have not been characterised. It would be prudent when the trench alignment for the proposed works passes close to this site that soil samples are collected and analysed for the presence of petroleum hydrocarbons and that vapours within the trench are similarly assessed to determine both the toxic and flammability risks to workers. 4.4.2 Mitigation At the Heathcote River, the results of the investigation indicate that contaminant concentrations from the identified uncontrolled fill are not at levels that would pose a human health risk to construction workers and the general public. However, there are a number of issues to consider with respect to working in land containing elevated levels of contaminants, including the health and safety of workers in the area, and the handling and disposal of contaminated material during excavations and dewatering. Mitigation measures include:  Sending excess soil excavated from this area to Kate Valley as special waste, as the lead concentrations are expected to be in excess of Class A landfill Acceptance Criteria as indicated by initial site investigations;

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 Identifying health and safety procedures for workers, contractors and the public for instances when contaminated land is encountered. These include (but are not limited to) site control measures, hazard identification protocols, and hazard minimisation procedures. At 25 Colombo Street, there is a possibility that excavation works may encounter unexpected contamination. If material suspected of being contaminated is encountered during the works, soil samples should be obtained and analysed to determine the nature and concentrations of contaminants. This will enable risks to human health and the environment to be appropriately assessed and soil disposal options clarified, based on the analytical results. It will also be prudent to use a portable gas analyser to measure the concentrations of vapours potentially present within the trench to thus enable risks to workers entering the trench to be satisfactorily addressed. If the soil is significantly contaminated, as shown by laboratory results, protective clothi ng including gloves and possibly respiratory protection may be necessary; this would be determined using a risk assessment approach and taking into account the nature of contaminants and their concentrations, as determined by sample analysis.

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5 Consultation

The project involves the installation of pipeline within the road reserve. The applicant will communicate with landowners adjacent to the road reserve on the timing and duration of construction activities, and any alternative access requirements required. Such communication is typically undertaken prior to the commencement of works, and is considered appropriate in this instance. Further to the above, no parties were identified as affected by the potential effects arising from the activity requiring consent (earthworks within a confined aquifer), and consequently no consultation was deemed necessary. The primary effects of the project relate to works within the CCC’s road network and impacts on traffic management. As with other projects of this nature, the CCC will continue to coordinate with internal stakeholders, as needed.

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6 Statutory assessment

6.1 Overview

Section 104 of the RMA sets out the matters a consent authority must, subject to Part 2 of the RMA, have regard to when considering resource consent applications. The various effects of the Project, as required by Section 104(1)(a) of the RMA, are assessed within Section 4 of this Report. The matters that are of relevance in considering these applications, as required by Section 104(1)(b) of the RMA, are the following statutory standards, policy statements and plans:

 National Policy Statement for Freshwater Management;  National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health;

 Canterbury Regional Policy Statement; and  Canterbury Land and Water Regional Plan. 6.2 National Policy Statement for Freshwater Management

The National Policy Statement for Freshwater Management (NPS) sets out the objectives and policies for freshwater management under the RMA. The NPS endeavours to safeguard freshwater ecological and human health values through the sustainable management of land and discharges of contaminants, manage freshwater quantity, manage by catchments, and provide for community and tangata whenua involvement in management. Decision-makers under the RMA must have regard to the objectives and policies when making resource consent decisions. Table 6-1 below identifies the provisions of the NPS that are relevant to the Project. Table 6-1: Relevant Provisions (NPS) Theme and Relevant Comment Provision As noted above, the Heathcote River crossing will be done by trenchless technologies, which are unlikely to result in adverse effects on the Safeguard the life-supporting Heathcote River, as it avoids disturbance of the riverbed or margins. There capacity, ecosystem processes is the potential for sediment from construction activities and sites to enter and indigenous species, and into the River, due to the proximity of construction sites to the riparian the health of people of margins. communities which come into Erosion and sediment control measures will be in place during construction contact with freshwater activities. These measures are expected to contribute towards the safeguarding of the life-supporting capacity of the waterbodies and ensure Objective A1 the overall freshwater quality in the Heathcote River is maintained. Overall, it is considered that the Project will be consistent with the NPS, and help achieve Objective A1.

6.3 National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health The Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (NES:Soil) relates to the assessment and management of health effects from exposure to contaminants in soil. The NES:Soil applies a framework for assessing contaminants in soil and provides a national set of planning controls and soil contaminant values. In assessing the lead concentration at the Heathcote River, the land use soil contamination standard considered relevant is the SCS for a commercial/industrial land use (3,300mg/kg). The concentration

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found in the sample (1,840mg/kg) is comfortably less than the land use SCS value for lead, and lead concentrations are thus not at levels that would pose a human health risk. No approvals are therefore required under the NES: Soil. 6.4 Canterbury Regional Policy Statement

The purpose of the Canterbury Regional Policy Statement (CRPS) is to set out objectives, policies and methods to resolve those resource management issues and to achieve the integrated management of the natural and physical resources of Canterbury. Table 6-2: Relevant Provisions (CRPS)

Theme and Relevant Provisions Comment

The Project is considered to be regionally significant infrastructure under the CRSP, as it is meets the following criteria:

Location, design and function of development (Entire “Sewage collection, treatment and disposal Region) networks.” With the exception of the Heathcote River crossing, Development is located and designed so that it the Project will be co-located within the road reserve functions in a way that is compatible with, and will with other existing infrastructure and services. This result in the continued safe, efficient and effective use location – as it allows for ease of access for future of regionally significant infrastructure operational and maintenance requirements – will enable the safe, efficient and effective use of Objective 5.2.1(2)(f) regionally significant infrastructure. At the Heathcote River crossing, access for operational and maintenance purposes can be done via access at either side of the crossing.

Sewerage, stormwater and potable water infrastructure (Wider Region) Within the wider region, enable sewerage, stormwater and potable water infrastructure to be developed and used, provided that, as a result of its location and design (a) the adverse effects on significant natural Refer above. and physical resources are avoided, or where this is not practicable, mitigated; and (b) other adverse effects on the environment are appropriately controlled. Policy 5.3.6(2)

Protection of intrinsic value of waterbodies and their There is the potential for sediment from construction riparian zones activities and sites, which are close to the riparian The overall quality of freshwater in the region is margins of the Heathcote River, to enter into the river maintained or improved, and the life supporting during this time. capacity, ecosystem processes and indigenous Erosion and sediment control measures will be in species and their associated fresh water ecosystems place during construction activities. These measures are safeguarded. are expected to contribute towards the safeguarding of the life-supporting capacity of the waterbodies and Objective 7.2.3 ensure the overall freshwater quality in the Heathcote River is maintained.

Halting the decline of Canterbury’s ecosystems and The banks of the Heathcote River are home to indigenous vegetation species. The construction indigenous biodiversity methodology enables the vegetation to remain intact.

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Theme and Relevant Provisions Comment The decline in the quality and quantity of Canterbury’s ecosystems and indigenous biodiversity is halted and their life-supporting capacity and mauri safeguarded. Objective 9.2.1

Protection of significant indigenous vegetation and habitats Areas of significant indigenous vegetation and As above. significant habitats of indigenous fauna are identified and their values and ecosystem functions protected. Objective 9.2.3

To facilitate the installation of the pipeline below the Heathcote River, construction activities under the bed of, and within the riparian margins of the river, will be Provision for activities in beds and riparian zones and required. Potential effects on the bed of the river will protection and enhancement of bed and riparian zone generally be avoided through the use of trenchless values technologies, which will install the pipeline below the river bed, avoiding disturbance and impacts to the Enable subdivision, use and development of river and values of the river. lake beds and their riparian zones while protecting all significant values of those areas, and enhancing Within the riparian margins, erosion and sediment control measures will be in place during construction those values in appropriate locations activities. These measures are expected to contribute Objective 10.2.1 towards the safeguarding of the life-supporting capacity of the waterbodies and ensure the overall freshwater quality in the Heathcote River is maintained.

Activities in river and lake beds and their riparian zones To provide for activities in river and lake beds and their riparian zones, including the planting and removal of vegetation and the removal of bed material, while recognising the implications of the Refer above. activity on the whole catchment; ensuring that significant bed and riparian zone values are maintained or enhanced; or avoiding significant adverse effects on the values of those beds and their riparian zones Policy 10.3.1

Protection and enhancement of areas of river and lake beds and their riparian zones To preserve the natural character of river and lake beds and their margins and protect them from inappropriate subdivision, use and development, and As above. where appropriate to maintain and/or enhance areas of river and lake beds and their margins and riparian zones Policy 10.3.2

It is considered that the Project is consistent with the provisions of the CRPS.

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6.5 Canterbury Land and Water Regional Plan 2015

The Canterbury Land and Water Regional Plan (LWRP) provides the framework for the management of land and water resources within Canterbury. A number of activities associated with the proposed works require consideration under the LWRP, including:

 Stormwater discharge during construction;  Site dewatering (take and associated discharge);  Drilling, tunnelling and disturbances in, on, or under the bed of a river;  Temporary discharge to water or land during construction;  Earthworks within 5m of the bed of a river; and

 Excavation over a Coastal Confined Aquifer. A number of these activities are permitted under the rules of the LWRP. An overview of these activities, and a comment on how the project will meet the permitted activity conditions is provided in Appendix B to this Report. As noted in Section 2.4 of this application, the Project requires consent as a restricted discretionary activity under Rule 5.176 of the CLWRP, as excavations will exceed 100m 3 and will occur within 50m of the Heathcote River. The exercise of discretion under Rule 5.176 is restricted to the following matters: Table 6-3: Matters of Discretion (CLWRP) Matter of Discretion Assessment

1. The actual and potential Erosion and sediment control measures will be in place during construction adverse environmental activities to ensure that any potential effects arising from sediment runoff to effects on the quality of the Heathcote River are appropriately managed. water in aquifers, rivers, Due to the depth of the Coastal Confined Aquifer (>10m b.g.l.), no effects lakes, wetlands or the sea; are anticipated on the aquifer as the Project will not intersect it during and construction. 2. Any need for remediation Site remediation (reinstatement) will occur once construction activities are or long-term treatment of completed. the excavation; and Given the high water table, excavations will extend below the groundwater level for the site. As such, dewatering of the trench will be required during 3. The protection of the construction activities. confining layer and As noted above, it is not anticipated that the Project will intersect the maintaining levels and Coastal Confined Aquifer. It is proposed that 1.0m of undisturbed material groundwater pressures in below the highest known groundwater level (at the location of excavation) in any confined aquifer, integrated into the construction methodology, to ensure the protection of the including any alternative confining layer and to maintain groundwater pressures. With implementation methods or locations for of this, and additional construction practices, it is anticipated that the risks the excavation; and associated with trench instability, dewatering and groundwater drawdown induced settlement can be managed, and the aquifer will remain protected. The taking of groundwater (and associated discharge) for the purpose of 4. The management of dewatering will be required as part of the Project. Exposed groundwater will exposed groundwater. be discharged to Christchurch City Council’s reticulated stormwater system.

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6.6 Other Matters

6.6.1 Heritage New Zealand Pouhere Taonga Act The Heritage New Zealand Pouhere Taonga Act (2014) (HNZPTA) seeks to promote the identification, protection, preservation, and conservation of the historical and cultural heritage of New Zealand. Section 42 of the HNZPTA states that no person may modify or destroy, or cause to be modified or destroyed, the whole or any part of that site if that person knows, or ought reasonably to have suspected, that the site is an archaeological site unless an authority is granted by Heritage New Zealand (formerly the New Zealand Historic Places Trust) under the HNZPTA. The location of the proposed works in not within, nor intercepts any known heritage sites or features identified in the Christchurch City Plan or the Christchurch Replacement District Plan. Although no known archaeological sites will be affected by the proposed works, the CCC will apply for an archaeological authority under Section 44(a) of the HNZPTA to cover all works undertaken for the Project as a precaution. 6.6.2 Mahaanui Iwi Management Plan 2013 The proposed works have been assessed against the Mahaanui Iwi Management Plan (2013), which is considered relevant to Project. There are a number of policies in the Plan which are considered relevant, including those relating to: a) Water quality; b) Sewage treatment; c) Protection of banks and margins of rivers; and d) Erosion and sediment control. With respect to b) above, as noted in Section 4 of this application, there are a number of positive effects associated with the Project. These include the reduction of overflows, which will minimise any potential impacts on freshwater environments and over time, improve the mauri of waterways within the vicinity of the Project. With respect to points a), c) and d), erosion and sediment control measures will be in place during construction activities to ensure that any potential effects arising from sediment runoff to the Heathcote River are appropriately managed. 6.6.3 Utilities Access Act 2010 The Utilities Access Act 2010 establishes a framework for a national code of practice to regulate how utility operators (including water and wastewater operators) and corridor managers coordinate their activities relating to access to transport corridors. Under the Act, the National Code of Practice for Utility Operators’ Access to Transport Corridors has been developed and came into effect on 1 January 2012. The Code seeks to minimise disruptions to roads, motorways, and railways caused by work by utility operators and maintain safety. The construction activities associated with the project will be undertaken in accordance with the requirements of the Code and any required Corridor Access Requests will be sought prior to construction commencing.

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7 Part 2 Assessment – Purpose and Principles

The following table provides an assessment of the Project against the RMA Principles that are considered to be relevant. Table 7-1: Part 2 Assessment Matters of National Assessment Importance (s6) The Project, which is regionally significant infrastructure, will provide (a) the preservation of the additional wastewater conveyance to service the Colombo-Beckenham and natural character of the coastal reduce wastewater overflows. During construction, sites adjacent to the environment (including the margins of the Heathcote River will be required to facilitate the installation of coastal marine area), wetlands the pipeline below the river. As there will be no works within the riparian and lakes and rivers and their margins (e.g. tree or vegetation removal), and no works within the river itself, margins and the protection of it is considered that the natural character of the river in this location will not them from inappropriate be affected. subdivision, use and Erosion and sediment control measures will be put in place during development. construction to ensure that any runoff from construction activities are appropriately managed. It is anticipated that public access to and along part of the Heathcote River (d) the maintenance and will be temporarily restricted during construction activities for health and enhancement of public access safety reasons. Alternative access around the site will be available for the to and along the coastal marine temporary duration of construction activities, and access to and along the area, lakes, and rivers: river will be restored following the completion of works. (f) the protection of historic The Project will have no effect on any known site of historic heritage value. heritage from inappropriate An Authority for the project will be sought under Section 44(a) of the HNZPTA subdivision, use, and as a precaution prior to the start of earthworks. development.

Other Matters (s7)

The banks of the Heathcote River are home to indigenous vegetation species. The intrinsic value of this ecosystem will remain intact, and erosion and (d) intrinsic value of ecosystems sediment control measures will be put in place to ensure that any potential effects on this area are managed appropriately. Temporary adverse effects on the quality of environment may occur during (f) maintenance and construction activities. However, as discussed in Section 4, it is considered enhancement of the quality of that these can be appropriately managed. In the long term, it is considered the environment that the quality of the environment will be maintained and enhanced through the provision infrastructure that reduces overflows in the network.

With regards to Section 8 of the RMA it is considered that the Project has taken into account the principles of the Treaty of Waitangi with respect to the use of natural and physical resources, as it has considered policies and issues in the Mahaanui Iwi Management Plan, and has considered whether any sites of cultural value or significance will be affected by the proposed works. Section 2.1 notes that the bed and banks of rivers have high potential for archaeological discovery due to the connection with mana whenua to waterways and also the likely pre-1900 European use of waterways. The CCC will apply for an archaeological authority under Section 44(a) of the HNZPTA to cover all works undertaken for the Project as a precaution, and an accidental discovery protocol will be put in place. Taking the above into account, it is considered that the Project is consistent with Sections 6, 7 and 8 of the RMA. With regards to the purpose of the RMA, it is considered that the issues, once distilled down, relate to balancing the community and district-wide benefits of the Project against the adverse construction

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effects, and whether there are appropriate mitigation measures that can effectively manage these effects. With respect to positive effects, the Project will address the current issues with wastewater overflows in the network, and:

 Enable the CCC to meet level of service requirements;  Minimise potentially harmful pathogens reaching freshwater environments;  Minimise the potential for adverse amenity effects on public areas and recreation values; and  Assist in the restoration of the mauri of waterways. With regards to adverse effects, it is considered that these predominantly relate to temporary effects that may arise during construction activities. With the adoption of appropriate mitigation measures and construction, it is anticipated that these effects can be appropriately managed. Tak ing the above into account, it is considered that the Project constitutes the sustainable management of natural and physical resources.

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8 Conclusion

The CCC has the responsibility of providing and maintaining the wastewater network for its communities. The Project will form an integral part of the wastewater network and, as outlined above will have a number of positive effects, particularly by providing necessary infrastructure to address overflows. During construction, there will be a range of potential adverse effects within the vicinity of the construction areas, but, with the adoption of proposed mitigation measures, any adverse effects will be temporary in nature and can be appropriately managed. Once completed, the majority of the Project works will be underground and temporary construction areas will be reinstated in an appropriate manner. It is considered that the Project is consistent with the purpose of the RMA in that it allows for the management of natural and physical resources in a way that enables people and communities to provide for their social, economic and cultural wellbeing and for their health and safety. The Project gives effect to, or is consistent with, the objectives and policies of the relevant statutory plans, and it is considered that the mitigation measures outlined in this application document will ensure that any associated adverse effects will be appropriately managed.

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Appendices

Colombo-Beckenham Wastewater Upgrade

Appendix A Geotechnical Assessment

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GEOTECHNICAL ASSESSMENT REPORT

COLOMBO STREET AND BECKENHAM STREET WASTEWATER

Prepared for Christchurch City Council December 2016

Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

This document has been prepared for the benefit of Christchurch City Council. No liability is accepted by this company or any employee or sub-consultant of this company with respect to its use by any other person.

This disclaimer shall apply notwithstanding that the report may be made available to other persons for an application for permission or approval to fulfil a legal requirement.

QUALITY STATEMENT

PROJECT MANAGER PROJECT TECHNICAL LEAD Chris Maguire Steph Thompson

PREPARED BY Matthew Shore CHECKED BY Daniel Goodman REVIEWED BY Steve Woods APPROVED FOR ISSUE BY Chris Maguire ………………………………...... 23/12/2016

CHRISTCHURCH Hazeldean Business Park, 6 Hazeldean Road, Addington, Christchurch 8024 PO Box 13-052, Armagh, Christchurch 8141 TEL +64 3 366 7449, FAX +64 3 366 7780

REVISION SCHEDULE

Signature or Typed Name (documentation on file). Rev Date Description No Prepared by Checked by Reviewed by Approved by

A 19/12/16 Final MS DG SW CM

Status: Final Project No.: 80508773 December 2016 Our ref: \\nzchc2s01\projects\_2012 Onwards\Christchurch City Council\80508773 CCC Colombo St Beckenham St WW\50 Tech\3 Geotech\Reporting\GAR\80508773 CCC Colombo St GAR.docx Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

Christchurch City Council Colombo Street and Beckenham Street Wastewater CONTENTS 1 Introduction ...... 1 1.1 Project Background ...... 1 1.2 Proposed Development ...... 1 2 Site Setting ...... 3 2.1 Site Conditions ...... 3 2.2 Published Geology ...... 4 2.3 Groundwater ...... 4 2.4 Seismic Design ...... 5 3 Anticipated Subsurface Conditions ...... 7 3.1 Information Sources...... 7 3.1.1 Pre-existing Information ...... 7 3.1.2 MWH Ground Investigation ...... 7 3.2 Subsurface Conditions ...... 7 3.2.1 Cashmere Road to Malcolm Ave ...... 7 3.2.2 Malcolm Ave to the Heathcote River ...... 8 3.2.3 Heathcote River Crossing ...... 8 3.2.4 Heathcote River to Fisher Ave ...... 9 3.2.5 Beckenham Street Cross Connection ...... 9 4 Precedent Site Earthquake Performance ...... 10 4.1 Likely Ground Motions ...... 10 4.2 Liquefaction and Lateral Spreading Observations ...... 10 4.3 Observed Crack Location Records ...... 11 4.4 Vertical and Horizontal Ground Movement Records ...... 11 4.5 Summary ...... 12 5 Liquefaction and Lateral Spreading Assessment ...... 13 5.1 Liquefaction Triggering ...... 13 5.2 Settlement Analysis ...... 13 5.2.1 Lateral Spreading Analysis ...... 13 6 Key Geotechnical Considerations ...... 15 6.1 Excavation Stability and Dewatering ...... 15 6.2 Groundwater Drawdown Induced Settlement ...... 15 6.3 Earthquake Performance ...... 15 6.4 Siphon River Crossing ...... 17 7 Conclusions and Recommendations ...... 19 7.1 Conclusions ...... 19

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7.2 Recommendations ...... 20 8 References ...... 21 9 Limitations ...... 22

LIST OF TABLES Table 2-1: Seismic Design Criteria ...... 6 Table 3-1: Summary of Soil Profile from Borehole Investigations ...... 8 Table 4-1: Estimated CES Ground Motions ...... 10

LIST OF FIGURES Figure 1-1: Colombo Street Wastewater Trunk Main ...... 2 Figure 1-2: Beckenham Street Cross Connection ...... 2 Figure 2-1: Heathcote River – trenchless pipeline crossing (viewed looking north) ...... 3 Figure 2-2: Published geological map (GNS, 2002) ...... 4 Figure 2-3: Median Groundwater Levels (from NZGD) ...... 5

APPENDICES Appendix A Drawings Appendix B Borehole Logs Appendix C CPT Logs Appendix D Hand Auger / DCP Logs Appendix E MWH Factual Geotechnical Report

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1 Introduction 1.1 Project Background MWH New Zealand Limited (MWH) have been commissioned by Christchurch City Council (CCC) to undertake the technical engineering design (preliminary and detailed), construction monitoring and construction administration services for the proposed Colombo Street Wastewater Trunk Main and Beckenham Street Cross Connection. This document summarises the findings of a geotechnical assessment undertaken to support detailed design. It represents an update to the preliminary geotechnical assessment report prepared to support preliminary design (MWH, 2016). It has been updated to incorporate the findings of a ground investigation completed to inform detailed design and a constructability assessment of the proposed Heactcote River siphon, to be constructed via trenchless construction. The geotechnical assessment has been undertaken in accordance with our fee proposal dated December 2015.

1.2 Proposed Development Reference is made to Detailed Design Drawings C100 to C105 and C200 to C202 (Appendix A). The proposed Colombo Street Wastewater Trunk Main comprises construction of (refer Figure 1-1):  Approximately 320 m of DN475 PVC-U gravity main and associated manholes from Centaurus Road to Malcolm Avenue (blue, Figure 1-1). Trenched construction, with invert depth ranging between approximately 2.0 and 3.5 m bgl.  Approximately 440 m of DN600 PVC-U gravity main and associated manholes from Malcolm Avenue to the Heathcote River, parallel to the existing gravity main (purple, Figure 1-1). Trenched construction with invert depth ranging between approximately 3.5 and 4.5 m bgl (exact method to be confirmed).  Approximately 30 m of DN560 PE gravity main beneath the Heathcote River (green, Figure 1-1). Trenchless construction, with invert depths of cover of between approximately 2.5 m 5.0 m bgl.  Approximately 130 m of DN600 PVC-U gravity main and associated manholes from the Heathcote River to Fisher Ave (pink, Figure 1-1). Trenched construction with invert depth ranging between approximately 3.5 and 4.0 m bgl.

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Figure 1-1: Colombo Street Wastewater Trunk Main

The proposed Beckenham Street Cross Connection comprises construction of (refer Figure 1-2):  Approximately 220 m of DN600 PVC-U gravity main and associated manholes between Fisher Ave and Tennyson Street (pink, Figure 1-2). Trenched construction with invert depth ranging between approximately 2.5 and 3.5 m bgl.  Installation of a flow control device on the Fisher Ave gravity main, within a conventional manhole.

Figure 1-2: Beckenham Street Cross Connection

Construction for both pipelines is to occur generally within the center of the road reserve. No significant existing service crossings are anticipated. Existing structures are anticipated to be setback a minimum distance of approximately 10 m from the centerline of the proposed pipelines. No man-made structures overlie the proposed trenchless crossing of the Heathcote River. It is understood the works are considered Importance Level 3, with a 100 year design life , as defined by NZS1170.

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2 Site Setting 2.1 Site Conditions The proposed development area comprises near-level to gently sloping . In general, the proposed development is to occur through residential areas. Some commercial properties are present along Colombo Street, which includes the Cashmere Shops at the southern end of Colombo Street, near the intersection with Cashmere Road. Colombo Street, between Cashmere Road and Fisher Ave, is an approximately 20 m wide road reserve. It includes a single carriageway in each direction, plus bus lane and footpath. Trees of various size are present adjacent to the road revere boundary along the proposed alignment. The Heathcote River at Colombo Street is considered a ‘non-tidal reach’ in the Canterbury Geotechnical Database. At the location of the proposed river crossing, the banks of the river are up to approximately 2 m high, and slope at up to approximately 45° (refer Figure 2-1). The river channel is approximately 8 m wide. The banks of the river are vegetated with grass and bushes, with some large trees. Hunter Terrace is present on the southern side of the river, with Beckenham Library beyond that (i.e. greater than 20 m from the river bank). Waimea Terrace is present on the northern side of the river, with residential dwellings behind.

Figure 2-1: Heathcote River – trenchless pipeline crossing (viewed looking north)

Beckenham Street is an approximately 15 m wide road reserve. Trees of various size are present adjacent to the road revere boundary along the project alignment. As detailed above, existing residential and commercial structures are anticipated to be set back a minimum distance of approximately 10 m from the centerline of the proposed pipeline. The proximity of existing structures to the proposed development will need to be confirmed during the early part of detailed design. The existing structures are of varying age, construction and condition, being less than two stories in height. No structures are known to be of high importance level or to be particularly sensitive (or their contents) to ground disturbance. Status: Final December 2016 Project No.: 80508773 Page 3 Our ref: 80508773 CCC Colombo St GAR Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

2.2 Published Geology The Geology of the Christchurch Area Geological Map (QMAP, 1:250,000, Forsyth et al. 2008) indicates the development area to be generally underlain by river deposits of Holocene age (Q1a, less than approximately 12,000 years old). These are described as ‘grey river alluvium beneath plains or low-level terraces’. (mQe), comprising ‘yellow brown windblown on Banks Peninsula, greater than 3 m thick and commonly in multiple layers’, is mapped in the vicinity of Cashmere Road and the Port Hills (i.e. elevated terrain). The Loess is of undifferentiated Pleistocene age. The Geology of the Christchurch Urban Area Geological Map (GNS 2002), at a 1:25,000 scale, provides further detail pertaining to likely subsurface conditions (refer Figure 2-2). The map indicates the site to be generally underlain by river alluvium, specifically the Yaldhurst Member of the Springston Formation (Figure 2-2, yellow). The Yaldhurst Member is described as ‘dominantly alluvial and silt overbank deposits’. The map indicates the area around Cashmere Road to be underlain by undifferentiated Colluvium, described as ‘valley fill and slopewash of loess-volcanic derived colluvium’ (Figure 2-2, pink).

Figure 2-2: Published geological map (GNS, 2002) 2.3 Groundwater Information on regional groundwater levels is presented with the New Zealand Geotechnical Database (NZGD). Median groundwater levels presented in the New Zealand Geotechnical Database are typically at between approximately RL 6.5 and 3.5 m (LVD), falling towards the Heathcote River (Figure 2-3). This equates to typically 2.0 to 4.0 m bgl. 15th to 85th percentile groundwater levels presented in the NZGD are approximately ± 0.5 m of the mean groundwater levels detailed above. Environment Canterbury (ECan) well logs indicate that the confined aquifer, in the Riccarton Gravel, is at depths of approximately 20 to 25 m bgl in the vicinity of the project area.

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Figure 2-3: Median Groundwater Levels (from NZGD)

2.4 Seismic Design Seismic design of the proposed development has been completed in accordance with NZS1170.5:2004, where the infrastructure is within the scope of the document. We are not aware of any specific municipal infrastructure performance criteria currently in place, in particular, for pipelines. We have used NZS1170 for seismic design guidance. Although pipes are not covered by NZS1170, they will eventually connect to structures that are and an understanding of pipeline performance relative to these structures is valuable. Serviceability Limit State (SLS) criteria is widely accepted to require prevention of damage to the infrastructure, with all aspects of operation unaffected. Ultimate Limit State (ULS) performance criteria typically requires preservation of life safety with significant levels of repairable damage generally acceptable.

As detailed above, the works have been classified as Importance Level 3 and to have a design life of 100 years. In accordance with NZS1170.5, seismic design criteria for the proposed works are specified in Table 2-1.

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Table 2-1: Seismic Design Criteria

Description Serviceability Limit state (SLS) Ultimate Limit State (ULS)

Annual Exceedance Probability 1/2,500 (AEP) 1/25

Spectral shape factor (T=0), Ch (T) 1.12 (Class D)

Hazard factor (Z) 0.3 (Christchurch)

Near fault factor (T, D) 1.0 (20 km or greater from major faults)

Return period factor (R) 0.25 1.8

Peak ground acceleration (g) 0.09* 0.61* *NZS1170 derived peak ground acceleration is associated with a M7.5 event

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3 Anticipated Subsurface Conditions The following subsections briefly summarise anticipated subsurface conditions with respect to the proposed development. Reference is made to Drawings C100 to C105 and C400 (Appendix A) for summary geological sections of subsurface conditions based upon the existing information. There is significant lateral and vertical variability within the Yaldhurst Member of the Springston Formation. On this basis, subsurface conditions may vary from those observed at the investigation locations.

3.1 Information Sources 3.1.1 Pre-existing Information The anticipated subsurface conditions have been developed using existing ground investigation data contained within the NZGD. For the purposes of the assessment, existing ground investigation data within approximately 25 m of the proposed pipeline centerline has been used. Referenced borehole logs are presented as Appendix B, CPT logs as Appendix C and hand auger/DCP logs as Appendix D. The following key information is presented on the geological sections:  Soil type (for ) or Soil Behavior Type (for CPT’s).

 SPT blowcount (uncorrected) (for boreholes) or correlated N60 SPT blowcount (for CPT’s)  Recorded groundwater level.  Inferred groundwater levels: o 15th percentile. o 85th percentile.

3.1.2 MWH Ground Investigation MWH completed a ground investigation at the location of the siphon river crossing in November 2016. The investigation comprised the drilling of two two sonic boreholes, one on each side of the river at the approximate location of the proposed siphon manholes. The investigation was to inform detailed design of the river siphon and identify constraints on construction. Reference is made to Appendix E for the Factual Geotechnical Report summarising the findings of the investigation.

3.2 Subsurface Conditions 3.2.1 Cashmere Road to Malcolm Ave Reference GI data: CPT 59166, BH 28274, HA 47258 Proposed invert depths and construction methodology: Invert depth between approximately 1.8 to 3.5 m bgl. Dig and lay. Anticipated subsoil conditions: Predominantly silty sands and sandy silts, ‘Very loose’ to ‘loose’ density. Some interbedded clays and sandy gravels possible. Likely variable ground conditions underlying Centaurus Road (i.e. colluvium, loess derived, varying consistency). Anticipated groundwater conditions: Groundwater levels likely to be below currently proposed pipe invert levels, based upon estimated 15th and 85th percentile groundwater levels in the NZGD.

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3.2.2 Malcolm Ave to the Heathcote River Reference GI data: CPT 209, BH 59122, CPT 201, HA 60205, CPT 6319, CPT 17188, BH 20407, BH 16412 Proposed invert depths and construction methodology: Invert depth between approximately 2.5 m and 4.2 m bgl. Dig and lay. Anticipated subsoil conditions: Predominantly silty sands and sandy silts, ‘very loose’ to ‘loose’ density. Some interbedded sandy gravel, which is more prevalent north of Thorrington Road, variable density (‘’medium dense’ to ‘very dense’). Anticipated groundwater conditions: Groundwater levels likely to be above currently proposed pipe invert levels, based upon both estimated 15th and 85th percentile groundwater levels in the NZGD. Up to approximately 1.0 m above pipe invert (85th percentile). Recorded groundwater levels in some boreholes indicate groundwater levels may be somewhat higher than this (BH 16412).

3.2.3 Heathcote River Crossing Reference GI data: CPT 21150, CPT 648, CPT 59205, CPT 59206, BH16412, BH1 and BH2 Proposed invert depths and construction methodology: Maximum invert depth approximately 5.0 m bgl. Minimum cover from river bed to top of pipe is 1.0 m. Trenchless construction, method to be confirmed. Anticipated subsoil conditions: See Table 3-1 for a summary of the material encountered within BH1 (southern bank) and BH2 (northern bank). Ground conditions for the crossing have been extrapolated between the boreholes. No investigations have been completed within the river bed. The proposed siphon will be constructed within the clayey SILT with organics, based upon completed investigations. There is the potential streambed sediment extends to siphon level (i.e. saturated soft/loose material).

Table 3-1: Summary of Soil Profile from Borehole Investigations

Depth (m bgl) Layer Uncorrected SPT N values BH01 BH02 Uncontrolled FILL 0 – 2.6 1 – 1.45 1 SILT with Organics - 1.45 – 2.3 32 Sandy GRAVEL/Gravelly SAND 2.6 – 4.0 2.3 – 4.1 27,27 Clayey SILT with Organics 4.0 – 7.0 4.1 – 8.5 2,5,6,4,1,1,2 SILT and Fine SAND 7.0 – 10.45 8.5 – 10.45 1,3,4,2,6,6

Material within the upper 2.6 m of BH01 and 1.45 m of BH02 was believed to be construction demolition material placed as fill due to the presence of whole bricks, crushed concrete and glass fragments.

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Anticipated groundwater conditions: Up to approximately 2.0 m above pipe invert, based upon estimated 85 th percentile groundwater levels in the NZGD. 15th percentile groundwater levels at or near pipe invert. Groundwater levels likely subject to river induced ‘mounding’. Groundwater levels likely vary with rainfall and river levels. Monitoring data indicates groundwater at 1.3 m bgl within BH1 (southern bank, RL 14.7 m) and 1.2 m bgl within BH2 (northern bank, RL 14 .5 m). Monitoring was undertaken in November 2016 and is therefore not judged representative.

3.2.4 Heathcote River to Fisher Ave Reference GI data: CPT 59205, CPT 648, CPT 21150, CPT 649 Proposed invert depths and construction methodology: Invert depth between approximately 3.6 and 3.9 m bgl. Dig and lay. Anticipated subsoil conditions: Predominantly silty sands and sandy silts, ‘very loose’ to ‘loose’ density. Some interbedded clays possible, of ‘soft’ to ‘stiff’ consistency. Anticipated groundwater conditions: Groundwater levels likely to be above currently proposed pipe invert levels, based upon both estimated 15th and 85th percentile groundwater levels in the NZGD. Up to approximately 1.0 m above pipe invert (85th percentile).

3.2.5 Beckenham Street Cross Connection Reference GI data: CPT 40390, CPT 8122 Proposed invert depths and construction methodology: Invert depth between approximately 2.6 m and 3.2 m bgl. Dig and lay. Anticipated subsoil conditions: Predominantly silty sands and sandy silts, ‘Very loose’ to ‘loose’ density. Some interbedded clays likely, of ‘soft’ to ‘stiff’ consistency. Anticipated groundwater conditions: Groundwater levels likely to be above currently proposed pipe invert levels, based upon both estimated 15th and 85th percentile groundwater levels in the NZGD. Up to approximately 1.5 m above pipe invert (85th percentile).

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4 Precedent Site Earthquake Performance The following subsections briefly summarise the precedent performance of the proposed development area under seismic loading as a result of the Canterbury Earthquake Sequence (CES). It is based upon information presented within the NZGD.

4.1 Likely Ground Motions Table 4-1 summarises ground motions which the development area is inferred to have been subjected to as a result of key within the CES. Data has been sourced from the NZGD (contours of PGA developed by O’Rouke et al. 2013).

Table 4-1: Estimated CES Ground Motions

Peak Ground Acceleration (g) Event Magnitude - range

September 2010 (Darfield) 0.22 7.1

February 2011 (Christchurch) 0.42/0.44 6.3

June 2011 (max of two events) 0.18/0.20 5.9/6.3 December 2011 (max of two 5.8/6.0 events) 0.14/0.16

4.2 Liquefaction and Lateral Spreading Observations is a phenomenon in which saturated, cohesionless soils lose their strength and over a short period of time due to the build-up of excess during cyclic loading such as that induced by earthquakes. The primary factors affecting the liquefaction potential of a soil deposit are:  intensity and duration of earthquake shaking.  soil type and relative density.  overburden pressures.  depth to groundwater. Soils most susceptible to liquefaction are clean (poorly graded), loosely compacted, sands, silty sands and non-plastic silts. The following subsections briefly summarise observed evidence for liquefaction and lateral spreading as detailed within the NZGD.

September 2010 Earthquake No liquefaction or associated effects were observed as a result of the September 2010 earthquake, based upon aerial imagery assessment and visual inspection.

February 2011 Earthquake For the February 2011 earthquake, aerial imagery indicated generally ‘moderate-severe liquefaction’ between Cashmere and the Heathcote River. Areas of ‘no observed liquefaction’ were observed on the eastern side of Colombo Street in the vicinity of the ‘Cashmere Shops’ and in the vicinity of Beckenham Street. Between the Heathcote River and Fisher Ave, ‘moderate-severe liquefaction’ is mapped on the western side of Colombo Street and ‘minor observed liquefaction’ or ‘no observed liquefaction’ on the eastern side.

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Visual inspection findings were generally consistent with aerial imagery review. The eastern side of Colombo Street between Cashmere Road and the Heathcote River, were typically mapped as ‘no observed ground cracking or ejected liquefied material’ or ‘minor ground cracking but no observed ejected liquefied material’. The western side of Colombo Street between Cashmere and Road and the Heathcote River is more variable, from ‘no observed ground cracking or ejected liquefied material’ to ‘no lateral spreading but large quantities of ejected material’. An area of ‘moderate to major lateral spreading; ejected material often observed’ is mapped on the southern side of the Heathcote River, on the western side of Colombo Street. The section of Colombo Street between the Heathcote River and Fisher Ave, was visually inspected to show ‘no observed ground cracking or ejected liquefied material’ on the eastern side of the road and vary on the western side from ‘no observed ground cracking or ejected liquefied material’ to ‘no lateral spreading but minor to moderate quantities of ejected material’. The area in the vicinity of Beckenham Street was mapped as ‘no observed ground cracking or ejected liquefied material’. Road inspections following the February 2011 earthquake indicated most streets on the western side of Colombo Street to contain ‘severe quantities of ejected material’, with limited inspection on the eastern side indicating ‘no observed ejected liquefied material’. Beckenham Street was mapped as ‘no observed ejected liquefied material’.

June 2011 Earthquake’s No liquefaction or associated effects were observed as a result of the June 2011 earthquakes. An area of ‘moderate-severe liquefaction’ was mapped immediately to the north of Tennyson Street, in the vicinity of Beckenham Street. Road inspections indicated the majority of inspected streets on the eastern side of Colombo Street, including Colombo Street itself and Beckenham Street, displayed ‘no observed ground cracking or ejected liquefied material’. Streets inspected on the eastern side of Colombo Street ranged from ‘no observed ground cracking or ejected liquefied material’ to ‘no lateral spreading but minor to moderate quantities of ejected material’.

December 2011 Earthquake No liquefaction or associated effects were observed as a result of the December 2011 earthquake, based upon aerial imagery assessment. Visual inspection of properties and roads were not completed.

4.3 Observed Crack Location Records Crack mapping was undertaken following the September 2010 and February 2011 earthquakes and the data has been present in the New Zealand Geotechnical Database. ‘Unclassified cracks’ were mapped in the vicinity of Cashmere Road and Colombo Street roundabout. No significant cracking was mapped within an approximately 50 m corridor of the proposed pipeline route between Cashmere Road and the Heathcote River. This is with the exception of an approximately 40 m long crack, defined as ‘<10 mm wide’, roughly parallel to the Heahtcote River near Ernlea Terrace. Several discontinuous ‘unclassified cracks’ were mapped in the vicinity of the Heathcote River, with Ernlea Terrace, Ashgrove Terrace, Hunter Terrace and in Colombo Street on the northern side of the river. No ground cracking was observed in the vicinity of Beckenham Street.

4.4 Vertical and Horizontal Ground Movement Records A series of LiDAR surveys have been presented within the NZGD and from this, vertical elevation changes in ground surface have been presented (before the CES and after the December 2011 earthquake). It is noted that the presented values are not solely liquefaction induced settlement, and also include a tectonic component. In summary, Colombo Street between Cashmere Road and the Heathcote River experienced subsidence typically in the range of -0.1 to -0.3 m. Higher ground settlements were observed on the western side of Colombo Street compared to the eastern side, particularly in the vicinity of Wherstead

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Road (up to -0.5 m). Higher magnitudes of subsidence were mapped between the Heathcote River and Fisher Ave, typically in the range of -0.1 to -0.4 m. Vertical settlement in the vicinity of Beckenham Street ranged between approximately -0.1 and -0.3 m, with higher values over the southern half of the street. Horizontal ground movement in the area show consistent movement towards the east. This is interpreted as representing ‘tectonic’ deformation. There is no evidence suggestive of significant lateral spreading (i.e. horizontal movement towards the Heathcote River).

4.5 Summary Information suggests that that no visual evidence for ejected liquefaction material was observed as a result of the September 2010, June 2011 (two events) and December 2011 (two events) earthquakes. All of these earthquakes are inferred to have subjected the site to ground m otions higher than the SLS design loading required for the proposed works (i.e. 0.09 g). However, the absence of visual evidence in the form of ejected material does not necessarily mean the subsoil’s did not liquefy in any of these earthquakes. Evidence indicates that the majority of the development area was mapped as ‘no observed ground cracking or ejected liquefied material’ to ‘minor ground cracking but no obvious ejected liquefied material’ following the February 2011 earthquake. This is with the exception of the area west of Colombo Street, in the vicinity of Wherstead Road. There is also limited evidence with the New Zealand Geotechnical Database suggestive of significant lateral spreading as a result of the February 2011 earthquake at the location of the proposed Heathcote River crossing, based upon the absence of mapped cracks and horizontal movement vectors.

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5 Liquefaction and Lateral Spreading Assessment The following subsections briefly summarise the methodology and results of a liquefaction/lateral spreading assessment undertaken to assess likely site response to SLS and ULS seismic loading. Reference is made to Drawings C100 to C105 (Appendix A) for a summary of the findings of the completed liquefaction induced settlement/lateral spreading analysis for the individual ground investigation locations.

5.1 Liquefaction Triggering Liquefaction triggering analysis based on CPT data was performed according to the method of Boulanger & Idriss (2014), which includes observations from the CES in its dataset. Liquefaction susceptibility of the material was discriminated between based on the Soil Behaviour Type Index limit presented in Robertson & Wride (1998). If the Soil Behaviour Type Index exceeded 2.6 the material was deemed to exhibit ‘-like behaviour’ and the layer was excluded from all liquefaction analysis. For triggering analysis based on data obtained from borehole logs, the SPT based methodology of Idriss & Boulanger (2014) was adopted. The NZS1170.5:2004 method of deriving design ground motion parameters was developed primarily for structural design and produces peak ground accelerations weighted to a moment magnitude of 7.5. Liquefaction triggering analyses typically use the earthquake magnitude as a measure of the number of significant cycles expected during the earthquake. As the PGA’s derived are magnitude weighted they do not necessarily reflect the true seismicity of the region and may lead to liquefaction triggering analyses predicting greater extents of liquefaction than potentially feasible. Other non-magnitude weighted methods of determining peak ground accelerations are available; however, as infrastructure connected to the network was likely designed according to the seismic parameters derived from NZS1170.5, use of weighted PGA’s was considered appropriate for this application.

5.2 Settlement Analysis For both the SPT and CPT sets of data, Seismic Compression Settlements were evaluated based on Tokimatsu & Seed (1987). This quantifies the vertical settlement in the non-liquefied layers including the crust. This was then added to the liquefaction induced vertical settlement which was determined by different methods for each in-situ test method. Expected liquefaction induced vertical settlements were evaluated for the CPT data using the methodology of Zhang et al. (2002). For SPT based analysis, liquefaction induced settlement was quantified according to the Ishihara & Yoshimine (1992) method. The design SLS peak ground acceleration of 0.09 g is not judged sufficient to trigger significant liquefaction, although liquefaction of very thin isolated layers may be triggered. Liquefaction of these layers is not expected to result in any observable surficial effects. This is consistent with precedent site performance during the recent CES. Under ULS loading (0.61g), analysis has shown calculated vertical settlements to be typically in the order of 100 to 250 mm. Higher magnitudes of vertical settlement were calculated in the vicinity of the Heathcote River and Wherestead Road (up to approximately 400 mm). This is consistent with the observed areas of greatest ground movement in the CES.

5.2.1 Lateral Spreading Analysis Estimates of lateral spread displacements for both CPT data and SPT data were based on the procedure of Youd et al. (2002). From experience, this method typically returns more realistic lateral spread predictions than other available methods which tend to grossly over-predict movement, particularly at locations adjacent to free faces such as the Heathcote River. The design SLS peak ground acceleration of 0.09 g is not judged sufficient to trigger lateral spreading. Lateral spreading analysis indicates significant lateral spreading is anticipated adjacent to the Heathcote River under the ULS seismic loading conditions (0.61g). Lateral spreading of greater than 1.0 m was calculated adjacent to the river (within 5 m of top of bank), decreasing to approximately 0.6 m at 15 metres distance from the top of bank (location of CPT648).

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The site is inferred to have been subjected to seismic loading in the vicinity of 0.45 g as a result of the February 2011 earthquake. An additional liquefaction triggering analysis was conducted using the seismic design parameters recorded during the February event. Results of this analysis indicated that the February 2011 earthquake ground motion parameters was predicted to generate broadly similar liquefaction-related damage as for the design ULS event. The extent of liquefaction was predicted to be slightly more widespread under the ULS event; however, in locations were liquefaction was triggered in both events surficial effects were near identical. Limited visual evidence for lateral spreading was observed as a result of the February earthquake. This indicates that the analysis methods adopted are likely to be conservative. However, as the ULS seismic loading is approximately 35% higher than the inferred shaking as result of the February 2011 earthquake significant lateral spreading cannot be precluded under the ULS ground motions. Significant displacements associated with lateral spreading are most likely to occur in the upper several meters where there is significant ‘free face’. On this basis, the trenchless constructed pipeline beneath the river is likely outside the zone of significant lateral spreading (invert depths of approximately 5.0 m). Lateral spreading is therefore more of a constraint on the manholes associated with the trenchless constructed pipeline. Another consideration associated with lateral spreading, is the potential for heave of the river bed . This occurs when significant lateral spreading of the banks occur, causing the invert of the stream and loose surficial deposits to be ‘heaved’ upwards. Should the trenchless constructed pipeline be impacted by river bed heave, this could cause significant damage (and would be costly and take time to repair). An assessment of potential heave associated with ULS lateral spreading has not been undertaken and any analytical attempt to quantify this is unlikely to be reliable. For the purposes of detailed design, the proposed trenchless crossing is to be constructed as deep as is reasonably feasible (based upon operational requirements and constructability).

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6 Key Geotechnical Considerations The following subsections briefly summarise some of the key considerations for design, construction and operation of the proposed development.

6.1 Excavation Stability and Dewatering The proposed works will comprise trenched excavations up to approximately 4.5 m bgl. The are expected to be constructed in variable ground conditions. Excavations of up to approximately 2.0 m below groundwater level may be required. Based upon existing GI information, key considerations for construction are as follows:  Expected materials will be readily excavatable using conventional earthmoving equipment.  Temporary excavation shoring will be required – due to the presence of silts and sands of varying density, below the water table.  Groundwater inflows into the excavations are expected – though the works could be scheduled to occur when groundwater levels are historically at their lowest to reduce the impact.  Groundwater inflows will likely be able to be controlled via sump pumping where inflows are lower (particularly if construction occur during summer).  Well pointing may be required in some locations, where groundwater inflows are higher.  Groundwater inflows, combined with varying density silts and sands, may cause instability of the trench walls and issues with the trench subgrade preparation. The risks associated with trench instability and dewatering can be managed by the use of the appropriate construction practices. Minimum requirements for construction are documented in the Project Specifications. Further assessment may be required during construction in the event of unforeseen ground conditions occurring.

6.2 Groundwater Drawdown Induced Settlement Settlement can occur where groundwater is drawdown, impacting existing structures. Groundwater drawdown is not expected to be a significant constraint on project construction due to:  Groundwater levels are likely to be required to be drawdown only approximately 2.0 m.  Existing structures are setback a minimum distance of approximately 10 m from the centreline of the proposed trench.  There are no known high importance level or particularly sensitive (or their contents) structures along the alignment.  There is no evidence in the existing ground investigation for highly compressible soils (e.g. peat). The risks associated with groundwater drawdown induced settlement can be managed by the use of the appropriate construction practices. Minimum requirements for construction are documented in the Project Specifications. This includes surveillance and monitoring, both of ground deformations and pre and post construction condition inspection of structures. Further assessment may be required during construction in the event of unforeseen ground conditions occurring.

6.3 Earthquake Performance In general, the effects of liquefaction at the site may include:  Settlement of the ground surface  Lateral spreading or permanent displacement of the ground

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 Reduction of of the liquefied soil resulting in reduced load-carrying capacity of foundations  Uplift of light buried structures such as pipes and manholes. The proposed work are specified as IL3 with a 100 year design life. On this basis, NZS1170.5 has been adopted as the basis of design, with a SLS earthquake of 1/25 AEP and a ULS earthquake of 1/2,500 AEP. Calculated design loads for these scenarios are 0.09 g and 0.61 g respectively. Analysis and precedent site performance under earthquake loading has shown that liquefaction (and its associated effects) is unlikely to occur under the SLS earthquake. The duration and intensity of shaking are judged not to be sufficient to trigger significant liquefaction and therefore SLS performance requirements are expected to be met. Under ULS loading however, liquefaction is expected to occur (together with its associated effects). This includes calculated large ground displacements (both vertical settlement and lateral spreading adjacent to the Heathcote River) and buoyancy of pipelines and structures. Considering site characteristics, the proposed development and the completed analysis, designing infrastructure to maintain ‘serviceability’ following the ULS earthquake is not judged to be economically feasible. On this basis, design for ULS earthquake has been focused upon the preservation of life safety with significant levels of repairable damage being acceptable. This means the adoption of a design philosophy which is focused around controlling the location and magnitude of damage and facilitating its ease of repair. Some of the key design methods that have been employed include:  Using pipe materials which accommodate some deformation (such as PE).  Using flexible joints/fittings which can accommodate some deformation. This includes the EQ slip sleeves either side of the trenchless crossing.  Making joints/fittings readily accessible and repairable. Both in terms of manholes, but also at shallower depths and with good access for equipment/personnel.  Locating infrastructure (where possible) outside of areas of likely lateral spreading (or significant areas of lateral spreading).  Pipes in the lateral spreading zone have been orientated perpendicular to the river as much as practical, to reduce loading.  Reducing the number of manholes or other structures susceptible to buoyancy.  Ensuring the trenchless construction of the Heathcote River is located below the zone of significant lateral spread and any possible stream/river invert heave. The most high risk areas for damage include:  Heathcote River area (within approximately 100 m) – this includes the pipeline and associated manholes for the trenchless crossing. The manholes have been designed as ‘fuse points’ where a repair could be readily made.  Wherstead Road area.  Beckenham Street area. The CCC IDS requires manholes to be designed against floatation under seismic conditions. Simplified buoyancy calculations have been completed for the critical locations conservatively assuming that all material located below the groundwater level has completely liquefied and neglecting any skin along the shaft of the manhole. Groundwater level for the seismic buoyancy calculations has been taken as the 85th percentile elevation interpolated from the regional groundwater data compiled by Tonkin & Taylor and contained within the New Zealand Geotechnical Database “GNS Science Median Water Table Elevations (Version 2) NZGD5160 (2014). Analysis revealed that static conditions with groundwater assumed at the ground surface (as required by the CCC IDS) governed for all manholes, and that all manholes possessed a factor of safety against floating of greater than 1.2 once additional hold-down concrete had been added.

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6.4 Siphon River Crossing The proposed trenchless river crossing is to be an approximately 30 m long DN560 SDR 17 PE100 pipe, located between two manholes. Ground conditions for the crossing are expected to comprise SILT, with some clay and wood fragments. Immediately above the siphon location, and in the banks of the river, sandy GRAVEL is present. The extent to depth of riverbed material is not known. Groundwater is expected to be at around 1.3 m bgl (up to 3.0 m above pipe invert level). The siphon crossing has limited ground cover at the lowest point of the river, approximately 600 mm (or one pipe diameter). The level of the siphon has been set by operational requirements and is as deep as is reasonably practical (with consideration of constructability, static buoyancy etc.). There is a risk the pipe may be exposed during a significant flood event, should bed erosion occur. We understand that there has been limited changes in bed level of the river in historic times and that there is no anecdotal information suggestive of erosion/bed level changes at the site. Flow velocities are relatively low. The pipe is made of PE, which is judged the preferred material from a flexibility and impact resistance perspective. Surveillance can be used as part of proactive risk management, in terms of monitoring areas of erosion and long-term changes in bed level. Maintenance can also be used, to ensure any streambed debris is removed which could cause localized erosion. As detailed above, the proposed trenchless constructed pipeline is likely below the zone of significant lateral spreading anticipated as a result of the ULS seismic loading. The crossing has been located as deep as is feasibly possible, based upon operational requirements and constructability to ensure it is located outside the potential heave zone associated with ULS lateral spreading. There are a variety of construction methods for trenchless construction. The preferred construction method is normally determined based upon consideration of the following:  Pipe diameter, pipe length and required pipe materials.  Vertical and horizontally alignment requirements (grades etc.).  Ground conditions (strength, consistency, etc.).  Groundwater levels.  Available construction areas.  Ground cover above pipeline invert.  Structures above pipeline. The preferred construction method has been left for the contractor to select. The specifications have been written to ensure design requirements are met, together with ensuring safe and appropriate construction practices are employed. At this stage, preliminary discussions with contractors have suggested pipe ramming may be the preferred solution. Pipe ramming has an advantage over other methods such as directional drilling, as it requires a smaller set-up area. Pipe ramming uses pneumatic percussive blows to drive a steel casing pipe through the ground. The casing pipe for this installation will be approximately 800mm in diameter. The PE siphon pipe will then be fed through this steel casing and welded at either end to the downward and upward PE bends (30 degree bend and 22.5 degree bend respectively). It is anticipated construction of the pipeline either side of the bends will be by open trench. For the purposes of assisting the contractor with selection of the preferred trenchless constructio n method, the key considerations can be summarised as follows:  The proposed trenchless crossing is short, approximately 30 m.  Limited cover is present between the top of the pipe and bed level (around one pipe diameter at point of lowest ground cover).  A large lay-down/work area is present on the southern bank (Hunter Terrace). Traffic management is easier at this location, as Hunter Terrace is a no-exit.  Limited space is present on the northern side of the proposed crossing location. Traffic management will be required on Waimea Terrace.  A residential dwelling is present within 10 m of the manhole location on the northern side of the proposed crossing location.  Existing services are present on both banks of the river.

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 Cover from the top of the proposed pipe to the invert of the river is minimal (approximately 0.5 m). The depth of softer/weaker material in the bed of the river is not known.  Geotechnical investigations were completed at each side of the crossing. No investigations were completed in the river. Ground conditions have been extrapolated between boreholes.  The proposed siphon is expected to be constructed in SILT, with some clay. The SILT is of soft to firm strength and of moderate to high plasticity (i.e. cohesive). Wood fragments were encountered in boreholes and therefore there is the potential for wood obstructions to be struck during trenchless construction.  Immediately above the pipe location, a sandy fine to coarse GRAVEL is present (non-plastic). This is medium dense. There is the potential for cobbles of up to approximately 300 mm to be encountered (unweathered, strong to very strong), which may provide significant obstructions.  The extent of streambed material is not known and nor is it known if this extends to the crown of the proposed siphon.  There is the potential for roots obstructions to be present, due to the presence of surrounding large vegetation.  There is the potential for ‘mixed face’ conditions to occur, which may cause issues for maintaining vertical and horizontal alignment.  Groundwater will be up to 3.0 m above pipe invert level. Groundwater levels will vary seasonally, with wet weather, and as a result of changes in river levels.  Construction methods will need to ensure no damage to existing infrastructure or the environment (i.e. compliance with issued consents).  Construction methods will need to ensure disturbance to neighbouring residents is as low as practical (vibration, noise etc.).

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7 Conclusions and Recommendations 7.1 Conclusions Based upon the findings of this assessment, it is concluded:  The project area is underlain by the Yaldhurst Member of the Springston Formation.  Existing ground investigation data indicates ground conditions to typically comprise predominantly silty sands and sandy silts of ‘very loose’ to ‘loose’ density. These sandy silts and silty sands are likely to be interbedded with some clays/silts and sandy gravels. Wood and cobbles may also be encountered.  Groundwater is expected to be encountered during construction. It is expected that groundwater is likely to be up to approximately 2.0 m above currently proposed trench inverts.  Assuming IL3 and a 100 year design life, ground motion parameters for design are 0.09 g (SLS) and 0.61 g (ULS, 1:2,500) and have been calculated as per NZS1170.5. These do not directly apply to the pipeline, which is outside the scope of NZS1170, but can be used to compare the expected behavior of the pipework to IL3 structures that it eventually connects to.  Information suggests that that no visual evidence for ejected liquefaction material was observed as a result of the September 2010, June 2011 (two events) and December 2011 (two events) earthquakes. All of these earthquakes are inferred to have subjected the site to ground motions higher than the SLS design loading required for the proposed works (i.e. 0.09 g).  The SLS design loading of 0.09 g is not judged sufficient to trigger significant liquefaction, based upon analysis and precedent site performance.  Evidence indicates that the majority of the development area was mapped as ‘no observed ground cracking or ejected liquefied material’ to ‘minor ground cracking but no obvious ejected liquefied material’ following the February 2011 earthquake. This is with the exception of the area west of Colombo Street, in the vicinity of Wherstead Road.  There is also limited evidence within the NZGD suggestive of significant lateral spreading as a result of the February 2011 earthquake at the location of the proposed Heathcote River crossing, based upon the absence of mapped cracks and horizontal movement vectors.  The ULS design loading of 0.61 g is larger than the Feb 2011 event ground motion and is sufficient to trigger liquefaction (along with its associated effects). The site subsoil’s are judged liquefaction susceptible.  For the ULS design loading, vertical settlements in the order of 100 to 250 mm have typically been calculated for existing ground investigation data. Higher magnitudes of vertical settlement were calculated in the vicinity of the Heathcote River and Wherestead Road (up to approximately 400 mm).  For the ULS design loading, lateral spreading analysis indicates significant lateral spreading is anticipated adjacent to the Heathcote River. Lateral spreading of greater than 1.0 m was calculated adjacent to the river (within 5 m of top of bank), decreasing to approximately 0.6 m at 15 m from top of bank.  On this basis, significant ground deformations are predicted under the ULS scenario, albeit that conventional analysis techniques are likely to over predict effects on the site. It is not judged feasible to design infrastructure to remain ‘serviceable’ under this condition and therefore the design approach of controlling the locations and magnitude of damage, and the ease of repair, has been adopted.  Some of the key design methods that have been employed include: o Using pipe materials which accommodate some deformation (such as PE). o Using flexible joints/fittings which can accommodate some deformation. This includes the EQ slip sleeves either side of the trenchless crossing. o Making joints/fittings readily accessible and repairable. Both in terms of manholes, but also at shallower depths and with good access for equipment/personnel. o Locating infrastructure (where possible) outside of areas of likely lateral spreading (or significant areas of lateral spreading).

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o Pipes in the lateral spreading zone being oriented perpendicular to the river as much as practical, to reduce loading. o Reducing the number of manholes or other structures susceptible to buoyancy. o Ensuring the trenchless construction of the Heathcote River is located below the zone of significant lateral spread and any possible stream/river invert heave.

7.2 Recommendations Based upon the findings of this assessment, it is recommended:  IL and Design Life – the recommended assigned importance level and design life for the works should be adopted. This is to ensure the proposed works are designed in a consistent manner with the overall ‘scheme’ infrastructure.  ULS Earthquake Performance Criteria – CCC adopt the approach for ULS design of the preservation of life safety with significant levels of repairable damage being acceptable. This would mean the adoption of a design philosophy which is focused around controlling the location and magnitude of damage under the ULS scenario and facilitating its ease of repair.  ULS Earthquake Design – that the measures documented in this report are adopted where possible to control the location and magnitude of damage due to an ULS scenario and facilitate their ease of repair. If required, emphasis should be placed upon high risk areas, which include: o Heathcote River area (within approximately 100 m). o Wherstead Road area. o Beckenham Street area.  Construction Specifications - The risks associated with trench instability, dewatering and groundwater drawdown induced settlement can be managed by the use of the appropriate construction practices. The risks are considered ‘typical’ for Christchurch dig and lay construction (i.e. no unusual site specific considerations). Minimum requirements for construction are documented in the Construction Specifications and should include pre and post construction condition inspections.  Constructability – Construction will be easier if undertaken when groundwater levels are at their seasonal lowest. This will help reduce the risk associated with excavation instability and subgrade preparation, excavation dewatering and groundwater drawdown induced settlement. On this basis, construction works should be scheduled and executed when groundwater levels are typically at their lowest if possible.  Trenchless River Crossing – The preferred construction method has been left for the contractor to select. The specifications have been written to ensure design requirements are met, together with ensuring safe and appropriate construction practices are employed. The contractor should make consideration of the items in this report in the selection of their proposed trenchless construction method.

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8 References Boulanger, R.W. and Idriss, I.M. (2014), "CPT and SPT Based Liquefaction Triggering Procedures," UC Davis Centre for Geotechnical Modelling Report No. UCD/CGM-14/01, 1-134.

Brown, L J, Weeber, J H. (1992). Geology of the Christchurch Urban Area, 1:25,000 geological map, 104 p.

Forsyth, P.J.; Barrell, D.J.A.; Jongens, R. (compilers) 2008, Geology of the Christchurch area: scale 1:250,000. Lower Hutt: GNS Science. Institute of Geological & Nuclear Sciences 1:250,000 geological map 16. 67 p. + 1 folded map

Ishihara, K. and Yoshimine, M. (1992), "Evaluation of settlements in sand deposits follo wing liquefaction during earthquakes," Soils and Foundations, Japanese Geotechnical Society, 32 (1), 173-188. New Zealand Standards Committee (2004) “NZS1170.5:2004, Structural Design Actions – Part 5: Earthquake Actions – New Zealand”

NZS1170.5. New Zealand Standard, Part 5 : Earthquake Actions – New Zealand.

Robertson, P.K. and Wride, C.E., (1998). Evaluating cyclic liquefaction potential using the . Canadian Geotechnical Journal, Ottawa, 35(3): 442-459.

Tokimatsu, K. and Seed, H.B. (1987), "Evaluation of settlements in sands due to earthquake shaking," J. of Geotech. Eng., ASCE 113 (GT8), 861-878.

Youd, T. L., Hansen, C. M., & Bartlett, S. F. (2002). “Revised multilinear regression equations for prediction of lateral spread displacement”. Journal of Geotechnical and Geoenvironmental Engineering, 128(12), 1007-1017.

Zhang, G., Robertson, P.K. and Brachman, R.W.I., (2002), “Estimating Liquefaction induced Ground Settlements From CPT for Level Ground”, Canadian Geotechnical Journal, 39(5): 1168-1180

Zhang, G, Robertson, P.K. and Brachman, R.W.I. (2004), "Estimating liquefaction-induced lateral displacements using the standard penetration test or cone penetration test," J. of Geotech. & Geoenv. Eng., ASCE 130 (8), 861-871.

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9 Limitations This report has been prepared for Christchurch City Council in accordance with the generally accepted practices and standards in use at the time it was prepared. MWH accepts no liability to any third party who relies on this report. The information contained in this report is accurate to the best of our knowledge at the time of issue. MWH NZ has made no independent verification of this information beyond the agreed scope set out in the report. The interpretations as to the likely subsurface conditions contained in this report are based on the site observations and field investigations made at discrete locations as described in this report. The type, spacing and frequency of the investigations, sampling, and testing of materials were selected to meet the technical, financial and time requirements agreed by the client. MWH NZ accepts no liability for any unknown or adverse ground conditions that would have been identified had further investigations, sampling, and testing been undertaken. Actual ground conditions encountered may vary from the predicted subsurface conditions. For example, subsurface groundwater conditions often change seasonally and over time. No warranty is expressed or implied that the actual conditions encountered will conform exactly to the conditions described herein. Where conditions encountered at the site differ from those inferred in this report MWH NZ should be notified of such changes, and should be given an opportunity to review the report recommendations made in this report in light of any further information. This report does not purport to describe all the site characteristics and properties. Subsurface conditions and testing relevant to construction works must be undertaken and assessed by any contractors as necessary for their own purposes.

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Appendix A Drawings

80508773-01-001 C100 Colombo Street (Sheet 1) 80508773-01-001 C101 Colombo Street (Sheet 2) 80508773-01-001 C102 Colombo Street (Sheet 3) 80508773-01-001 C103 Colombo Street (Sheet 4) 80508773-01-001 C104 Beckenham Street CN4600001677 C400 Siphon Geotechnical Investigations

Note sketches C100 to C104 are based on the Preliminary Design Drawings issued and not the Final design Drawings. The alignment and design details has not changed significantly so these are considered adequate for the purpose of geological cross sections.

Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

Appendix B Borehole Logs

BH 16412 BH 20407 BH 28274 BH 59172

BH 16412 TONKIN & TAYLOR LTD SHEET 1 OF 2 BH No: CHM-POD01-BH001 Hole Location: 1A Ernlea Terrace BOREHOLE LOG

PROJECT: CHCH TC3 GEOTECHNICAL INVESTIGATIONS LOCATION: CASHMERE JOB No: 52003.000 CO-ORDINATES: 5738338.99 mN DRILL TYPE: Roto-Sonic HOLE STARTED: 2/10/12 2480650.3 mE HOLE FINISHED: 2/10/12 DRILL METHOD: PQDT/Auto SPT R.L.: 6.36 m DRILLED BY: Pro-Drill DATUM: NZMG, MSL (CCC 20/01/12 Datum -9.043m) DRILL FLUID: LP2000 LOGGED BY: RDCL-BM CHECKED: BMcD GEOLOGICAL ENGINEERING DESCRIPTION

GEOLOGICAL UNIT, SOIL DESCRIPTION GENERIC NAME, Soil type, minor components, plasticity or ORIGIN, particle size, colour. MINERAL COMPOSITION. (mm) (kPa) (MPa)

WEATHERING ROCK DESCRIPTION TESTS STRENGTH

COMPRESSIVE Substance: Rock type, particle size, colour, DEFECT DEFECT SPACING SHEAR STRENGTH SHEAR minor components.

Defects: Type, inclination, thickness, roughness, filling. 10 25 50 100 200 1 5 20 50 100 250 50 250 1000 2000

FLUID LOSS FLUID WATER (%) RECOVERY CORE METHOD CASING R.L. (m) (m) DEPTH LOG GRAPHIC CLASSIFICATION SYMBOL MOISTURE CONDITION STRENGTH/DENSITY CLASSIFICATION 0 1 2 3 4 5 0 1 2 3 4 5 6 7 0 1 2 3 4 5 SAMPLES YALDHURST GW W Sandy fine to coarse GRAVEL with some silt MEMBER OF and trace cobbles, dark brownish grey, THE 6 subrounded, wet, well graded. Sand is fine to SPRINGSTON coarse. FORMATION

(ALLUVIAL) 100 PQDT 1 1

5 1.5m- no SPT due to cobbles. 1.5 to 1.95m- no recovery.

2 2 70

PQDT 4

3 3 1/1/1/1/1/1// MD 3.0m- medium dense.

0 2/1/1/2/1/2/ 3.0 to 3.45m- no recovery. SPT 2/1/2/2/2/1 3 N=19

4 4 100 ML VSt SILT, brownish grey, very stiff wet, low PQDT plasticity. 2 1/1//1/1/1/1 F 4.5m- firm. N=4 100 SPT 5 5 5.0 to 5.15m- some organics.

1 ML SILT with some sand and some organics, dark 100

PQDT greyish black, firm, wet, low plasticity. Sand is [email protected] fine. [email protected] 6 6 0/0//0/1/2/2 N=5 100 SPT 0 SP L Silty fine to medium SAND, light brownish grey, loose, wet, poorly graded.

7 7 100 PQDT

-1 1/2//3/3/3/3 MD 7.5m- medium dense. N=12 100 SPT 8 8

8.2m- minor fine to coarse gravel, rounded. -2 100 PQDT

9 9 1/0/0/1/0/1// L 9.0 to 9.45m- no recovery.

0100 0/0/1/1/0/0/ 9.0m- loose. SPT 1/0/0/2/2/2 -3 N=9 GW Sandy fine to coarse GRAVEL, brownish grey,

PQDT 10 subrounded, loose, wet, well graded. Sand is T+T_DATATEMPLATE-SPT.GDT rcb T+T_DATATEMPLATE-SPT.GDT Log Scale 1:50 BORELOG-TC3 720016 CHM-POD01.GPJ 8-Mar-2013 BH 16412

TONKIN & TAYLOR LTD SHEET 2 OF 2 BH No: CHM-POD01-BH001 Hole Location: 1A Ernlea Terrace BOREHOLE LOG

PROJECT: CHCH TC3 GEOTECHNICAL INVESTIGATIONS LOCATION: CASHMERE JOB No: 52003.000 CO-ORDINATES: 5738338.99 mN DRILL TYPE: Roto-Sonic HOLE STARTED: 2/10/12 2480650.3 mE HOLE FINISHED: 2/10/12 DRILL METHOD: PQDT/Auto SPT R.L.: 6.36 m DRILLED BY: Pro-Drill DATUM: NZMG, MSL (CCC 20/01/12 Datum -9.043m) DRILL FLUID: LP2000 LOGGED BY: RDCL-BM CHECKED: BMcD GEOLOGICAL ENGINEERING DESCRIPTION

GEOLOGICAL UNIT, SOIL DESCRIPTION GENERIC NAME, Soil type, minor components, plasticity or ORIGIN, particle size, colour. MINERAL COMPOSITION. (mm) (kPa) (MPa)

WEATHERING ROCK DESCRIPTION TESTS STRENGTH

COMPRESSIVE Substance: Rock type, particle size, colour, DEFECT DEFECT SPACING SHEAR STRENGTH SHEAR minor components.

Defects: Type, inclination, thickness, roughness, filling. 10 25 50 100 200 1 5 20 50 100 250 50 250 1000 2000

FLUID LOSS FLUID WATER (%) RECOVERY CORE METHOD CASING R.L. (m) (m) DEPTH LOG GRAPHIC CLASSIFICATION SYMBOL MOISTURE CONDITION STRENGTH/DENSITY CLASSIFICATION 0 1 2 3 4 5 0 1 2 3 4 5 6 7 0 1 2 3 4 5 SAMPLES YALDHURST GW W L fine to coarse. MEMBER OF Sandy fine to coarse GRAVEL, brownish grey, 100

THE PQDT -4 subrounded, loose, wet, well graded. Sand is SPRINGSTON 2/4//10/12/9/10 D fine to coarse. FORMATION N=41 10.5m- dense. 100 (ALLUVIAL) SPT 11 11

-5 100 PQDT

12 12 1/1/1/2/2/1// L 12.0 to 12.35m- no recovery. 1/2/2/1/2/1/

22 12.0m- loose. SPT 0/0/0/0/0/0 -6 ML St SILT with minor sand, light greyish brown, N=9 stiff, wet, low plasticity. Sand is fine.

13 GW L 13 100 Sandy fine to coarse GRAVEL, greyish brown, PQDT subrounded, loose, wet, well graded. Sand is -7 fine to coarse. 3/3/2/2/2/2// D 13.5m- dense. 3/2/2/2/3/2/

56 13.5 to 13.7m- no recovery. SPT 2/3/3/3/4/3 N=32 14 14

-8 100 PQDT

15 15 1/2/1/1/2/2// MD 15.0m-medium dense. 2/1/2/1/1/1/ 100 SPT 2/1/1/2/1/2 -9 N=17

16 16 100 PQDT

-10 1/1/1/1/1/2// D 16.5m- dense. 2/4/4/4/4/5 100 SPT 4/4/4/4/4/4 N=47 17 17

-11 100 PQDT

18 18 1/1/1/1/1/1// MD 18.0m- medium dense. 1/1/2/1/1/2 100 SPT 2/3/2/3/3/4 -12 N=25

19 19 100 PQDT SP Fine to medium SAND with minor silt, -13 brownish grey, medium dense, wet, poorly graded. End of borehole at 19.5mbgl (target depth)

20 T+T_DATATEMPLATE-SPT.GDT rcb T+T_DATATEMPLATE-SPT.GDT Log Scale 1:50 BORELOG-TC3 720016 CHM-POD01.GPJ 8-Mar-2013 BH 20407

TONKIN & TAYLOR LTD SHEET 1 OF 1 BH No: CHM-POD01-PDCPT001 Hole Location: 59 Colombo Street BOREHOLE LOG

PROJECT: CHCH TC3 GEOTECHNICAL INVESTIGATIONS LOCATION: CASHMERE JOB No: 52003.000 CO-ORDINATES: 5738280.35 mN DRILL TYPE: Roto-Sonic HOLE STARTED: 6/11/12 2480665.78 mE HOLE FINISHED: 7/11/12 DRILL METHOD: PQDT/Auto SPT R.L.: 8.49 m DRILLED BY: Pro-Drill DATUM: NZMG, MSL (CCC 20/01/12 Datum -9.043m) DRILL FLUID: LP2000 LOGGED BY: MOSS-NDB CHECKED: BMcD GEOLOGICAL ENGINEERING DESCRIPTION

GEOLOGICAL UNIT, SOIL DESCRIPTION GENERIC NAME, Soil type, minor components, plasticity or ORIGIN, particle size, colour. MINERAL COMPOSITION. (mm) (kPa) (MPa)

WEATHERING ROCK DESCRIPTION TESTS STRENGTH

COMPRESSIVE Substance: Rock type, particle size, colour, DEFECT DEFECT SPACING SHEAR STRENGTH SHEAR minor components.

Defects: Type, inclination, thickness, roughness, filling. 10 25 50 100 200 1 5 20 50 100 250 50 250 1000 2000

FLUID LOSS FLUID WATER (%) RECOVERY CORE METHOD CASING R.L. (m) (m) DEPTH LOG GRAPHIC CLASSIFICATION SYMBOL MOISTURE CONDITION STRENGTH/DENSITY CLASSIFICATION 0 1 2 3 4 5 0 1 2 3 4 5 6 7 0 1 2 3 4 5 SAMPLES YALDHURST GW M Sandy fine to coarse GRAVEL with minor silt, MEMBER OF brown, subrounded, moist, well graded. Sand is THE fine to coarse. SPRINGSTON 8 FORMATION 0.6 to 1.5m- no recovery. (ALLUVIAL) 40 PQDT 1 1

7

2 2 2.1 to 3.0m- no recovery. 40 PQDT 6 W 2.6m- wet.

3 3

5

47 3.7 to 4.5m- no recovery. PQDT 4 4

4

5 5 100 PQDT 3

6 6

2 100 PQDT 7 7

1 1/2/4/3/4/4// VD 7.5m- very dense. 4/4/4/4/4/5/ 100 SPT 5/5/4/5/5/1 for 7mm 8 7.95m- grey. 8 N>50

0 100 ML H Sandy SILT, brownish grey, hard, wet, low PQDT plasticity. Sand is fine to medium.

[email protected] 9 9 2/2//5/4/2/3 St 9.0m- stiff. N=14 100 SPT -1 End of borehole at 9.45mbgl (target depth)

10 T+T_DATATEMPLATE-SPT.GDT rcb T+T_DATATEMPLATE-SPT.GDT Log Scale 1:50 BORELOG-TC3 720016 CHM-POD01.GPJ 22-Mar-2013 BH 28274

METHOD OF SOIL DESCRIPTION USED IN BOREHOLE AND TEST PIT REPORTS

FILL CLAY (CL, CI or CH)

GRAVEL (GP or GW) ORGANIC SOILS (OL or OH or Pt)

SAND (SP or SW) COBBLES or BOULDERS

SILT (ML or MH)

CLASSIFICATION AND INFERRED STRATIGRAPHY

Soil and Rock is classified and described in Reports of Boreholes and Test Pits using the descriptions given in NZGS 2005 Field Description of Soil and Rock. The material properties are assessed by visual/tactile methods.

PARTICLE SIZE – NZGS 2005

Major Division Sub Division Particle Size

BOULDERS >200 mm

COBBLES 60 to 200 mm

Coarse 20 to 60 mm

GRAVEL Medium 6.0 to 20 mm

Fine 2.0 to 6.0 mm

Coarse 0.6 to 2.0 mm

SAND Medium 0.2 to 0.6 mm

Fine 0.06 to 0.2 mm

SILT 0.002 to 0.006 mm

CLAY < 0.002 mm

MOISTURE CONDITION – NZGS 2005

Symbol Term Description D Dry Sands and gravels are free flowing. Clays and silts may be brittle or friable and powdery. M Moist Soils are darker than in the dry condition and may feel cool. Sands and gravels tend to cohere. W Wet Soils exude free water. Sands and gravels tend to cohere. S Saturated Feels cool, darkened in colour and free water is present on the sample.

CONSISTENCY AND DENSITY – NZGS 2005

Undrained Shear Density SPT "N" Value Dynamic Cone Symbol Term Symbol Term Strength Index % (blows/300 mm) (blows/300 mm) VS Very Soft < 12 kPa VL Very Loose < 15 < 4 < 2 S Soft 12 to 25 kPa L Loose 15 to 35 4 to 10 1 to 3 F Firm 25 to 50 kPa MD Medium Dense 35 to 65 10 to 30 3 to 7 St Stiff 50 to 100 kPa D Dense 65 to 85 30 to 50 7 to 17 Vst Very Stiff 100 to 200 kPa VD Very Dense > 85 > 50 > 17 H Hard > 200 kPa

In the absence of test results, consistency and density may be assessed from correlations with the observed behaviour of the material. SPT “N-Values” are uncorrected. No correlation is implied between Standard Penetration Test (SPT) and Dynamic Cone Penetrometer Test values.

GANZL Form No. 10 RL0 June 2012 BH 28274

EXPLANATION OF METHOD OF SOIL DESCRIPTION USED IN BOREHOLE AND TEST PIT REPORTS

DRILLING/EXCAVATION METHOD

AS* Auger Screwing RD Rotary Blade or Drag Bit NQ Diamond Core – 47 mm AD* Auger Drilling RT Rotary Tricone bit NMLC Diamond Core – 52 mm *V V-Bit RAB Rotary Air Blast HQ Diamond Core – 63 mm *T TC-Bit, e.g. ADT RC Reverse Circulation HMLC Diamond Core – 63 mm HA Hand Auger PT Push Tube BH Tractor Mounted Backhoe ADH Hollow Auger CT Cable Tool Rig EX Tracked Hydraulic Excavator DTC Diatube Coring NDD Non-Destructive EE Existing Excavation WB Washbore or Bailer SON Sonic Drilling HAND Excavated by Hand Methods

WATER

Water level at date shown

GROUNDWATER NOT The observation of groundwater, whether present or not, was not possible due to OBSERVED drilling water, surface seepage or cave in of the borehole/test pit

GROUNDWATER NOT The borehole/test pit was dry soon after excavation. However, groundwater ENCOUNTERED could be present in less permeable strata. Inflow may have been observed had the borehole/test pit been left open for a longer period.

SAMPLING AND TESTING

SPT Standard Penetration Test to NZS4402 Test 6.5.1:1998 2,3 / 3,4,4,4 2,3 / 3,4,4,4 = Blows per 75 mm. N = 15 N = Blows per 300 mm penetration following 150 mm seating 30/60 mm Where practical refusal occurs, the blows and penetration for that interval are reported RW Penetration occurred under rod weight only HW Penetration occurred under the hammer and rod weight only HB Hammer double bouncing on anvil

DS Disturbed sample BDS Bulk disturbed sample G Gas sample W Water sample FP Field permeability test over section noted FV Field vane shear test expressed as uncorrected shear strength sv = peak value, sr = residual value PID Photoionisation Detector reading in ppm PM Pressuremeter test over section noted PP Pocket penetrometer test expressed as instrument reading in kPa U50 Thin walled tube sample – number indicates nominal sample diameter in milimetres WPT Water pressure tests DCP Dynamic cone penetration test CPT Static cone penetration test CPTu Static cone penetration test with pore pressure (u) measurement

SAMPLING AND TESTING

TCR = Total Core Recovery (%)

Length of core recovered = x 100 Length of core run

GANZL Form No. 10 RL0 June 2012 End Date Start Date Drill Method/Rig Driller Formation Soil BoreholeLog

Speight Drilling Graphic 26/06/2013 26/06/2013

CS1000 Log Becoming mediumdensewithnosiltfrom5.0metres Becoming loosetomediumdensefrom4.0metres poorly graded Fine tomediumSANDwithtracesilt,grey.Loose;wet; mottle. Firm;wet;lowplasticity;organics,roots SILT withminororganicsandtracesand,greyorange moist; lowplasticity;organics,roots SILT withtraceorganics,greyorangemottle.Firm; Medium GRAVEL;rounded.(FILL) Asphalt saturated; poorlygraded;gravel,finetomedium,rounded Fine tocoarseSANDwithminorgravel,grey.Loose; Becoming mediumdensebelow8.0metres Becoming loose,saturated,below7.0metres Checked By Logger Description Grid: RJS KJ NZTM Location: Vane testscompleted inaccordance withNZGSguideline Borehole loggedinaccordance withNZGSguideline"Fielddescription ofsoilandrock"2005 Groundwater elevationmeasuredat completionofdrilling. Hammer energyratio,Ce,0.95. Coordinates andelevationareestimates only. Remarks Christchurch 2A &2BWhersteadRoad,Cashmere, GP ML SP USC W M S Moisture Condition L-MD MD MD F L L L Consistency / Density Datum:

Water

Observations MSL 3.50 3.00 2.50 2.00 1.50 1.00 0.50 9.50 9.00 8.50 8.00 7.50 7.00 6.50 6.00 5.50 5.00 4.50 4.00 Depth

25 TCR (%) 50 75 100 (Uncorrected) N-value

10 SPT 20 30 40 Reference: Hole Depth(m): 450mm penetration 2, 2/3,1 Type: RaymondSplitSpoon Depth: 3.00m SPT N=8 450mm penetration 0, 1/1,3,2 Type: RaymondSplitSpoon Depth: 2.00m SPT N=7 450mm penetration 1, 1/2,2 Type: RaymondSplitSpoon Depth: 1.00m SPT N=8 450mm penetration 2, 3/1,3,2 Type: RaymondSplitSpoon Depth: 9.00m SPT N=8 450mm penetration 0, 2/2,4,3 Type: RaymondSplitSpoon Depth: 8.00m SPT N=11 450mm penetration 0, 0/2,1,2 Type: RaymondSplitSpoon Depth: 7.00m SPT N=5 450mm penetration 2, 4/5,7,6,8 Type: RaymondSplitSpoon Depth: 6.00m SPT N=26 450mm penetration 3, 4/6,8,7 Type: RaymondSplitSpoon Depth: 5.00m SPT N=27 450mm penetration 0, 1/2,1,3,4 Type: RaymondSplitSpoon Depth: 4.00m SPT N=10 Orientation (°): Inclination (°): Elevation (m): In-situ Testing Samples North (m): East (m): & Hole Depth 90 - 18.45 8 1570628 5176283

C GA_18460 Page 1of 2 e BH 28274 18.45m Ce m Drill cuttings Bentonite me e nt n Installation Backfill 1.05 0.25 0.05 t &

10 20 30 40 End Date Start Date Drill Method/Rig Driller Formation Soil BoreholeLog

Speight Drilling Graphic 26/06/2013 26/06/2013

CS1000 Log SILT, grey.Verysofttosoft;moistwet;highplasticity dense; moist;poorlygraded Fine tocoarseSANDwithtraceorganics,grey.Medium graded Fine tocoarseSAND,grey.Loose;wet-saturated;poorly SILT, grey.Firm;wettosaturated;lowplasticity saturated; poorlygraded;gravel,finetomedium,rounded Fine tocoarseSANDwithminorgravel,grey.Loose; Becoming densebelow17.0metres sand, finetocoarse moist towet;poorlygraded;gravel,subangularrounded; Sandy finetomediumGRAVEL,brown.Mediumdense; low plasticity Silty fineSAND,grey.Mediumdense;wet;poorlygraded; Checked By Logger Description Grid: RJS KJ NZTM Location: Vane testscompleted inaccordance withNZGSguideline Borehole loggedinaccordance withNZGSguideline"Fielddescription ofsoilandrock"2005 Groundwater elevationmeasuredat completionofdrilling. Hammer energyratio,Ce,0.95. Coordinates andelevationareestimates only. Remarks Christchurch 2A &2BWhersteadRoad,Cashmere, EOH: 18.45m MH SM GP ML SP SP USC M-W M-W W-S W M S Moisture Condition VS-S MD MD D F L L Consistency / Density Datum:

Water

Observations MSL 13.00 12.50 12.00 11.50 11.00 10.50 10.00 18.00 17.50 17.00 16.50 16.00 15.50 15.00 14.50 14.00 13.50 Depth

25 TCR (%) 50 75 100 (Uncorrected) N-value

10 SPT 20 30 40 Reference: Hole Depth(m): 450mm penetration 1, 0/0, Type: RaymondSplitSpoon Depth: 13.00m SPT N=0 450mm penetration 1, 1/0,0 Type: RaymondSplitSpoon Depth: 12.00m SPT N=1 450mm penetration 2, 3/7,6,8,7 Type: RaymondSplitSpoon Depth: 11.00m SPT N=28 450mm penetration 1, 0/3,2,2 Type: RaymondSplitSpoon Depth: 10.00m SPT N=8 450mm penetration 9, 12/12,10,11,10 Type: RaymondSplitSpoon Depth: 18.00m SPT N=43 450mm penetration 4, 9/8,10,9,7 Type: RaymondSplitSpoon Depth: 17.00m SPT N=34 450mm penetration 3, 10/8,6,5 Type: RaymondSplitSpoon Depth: 16.00m SPT N=27 450mm penetration 1, 2/2,4,5,12 Type: RaymondSplitSpoon Depth: 15.00m SPT N=23 450mm penetration 1, 0/0,2,1 Type: RaymondSplitSpoon Depth: 14.00m SPT N=4 Orientation (°): Inclination (°): Elevation (m): In-situ Testing Samples North (m): East (m): & Hole Depth 90 - 18.45 8 1570628 5176283 GA_18460 Page 2of 2 BH 28274 18.45m Drill Surrounding ground collapse

cuttings Installation 10.00 Backfill 1.05 &

10 20 30 40 BH 59172 Stronger Christchurch Infrastructure Rebuild Team

1 Magdala Place, Middleton PO Box 9341, Tower Junction, Christchurch 8149

GENERAL NOTES

a) This is a factual report of ground investigations.

b) This report was produced for the Stronger Christchurch Infrastructure Rebuild Team (SCIRT). This report is not intended for any other purpose.

c) The information contained in this factual report including associated electronic data files is for information only.

d) The ground investigations have been undertaken at discrete locations and no inferences about the nature and continuity of ground conditions away from the investigation locations are made.

e) No interpretation of investigation results has been made in this report.

f) It is recognized that the report may assist the wider community of Christchurch, and will therefore be uploaded to the Canterbury Geotechnical Database (CGD), and will be subject to the CGD terms of use.

g) Neither SCIRT nor The Christchurch City Council (CCC) accepts any responsibility or liability for any third party use, interpretation or dissemination of this report.

h) This report should in no way be relied upon without the professional advice of a geotechnical engineer.

SCIRT Geotechnical Factual Report General Notes rev 01 September 2012 BH 59172 Stronger Christchurch Infrastructure Rebuild Team

1 Magdala Place, Middleton PO Box 9341, Tower Junction, Christchurch 8149

KEY TO EXPLORATORY HOLE LOGS

Logging The logging of soils and rocks has been carried out in general accordance with The New Zealand Geotechnical Society, ‘Field Description of Soil and Rock – Guideline for the Field Classification and Description of Soil and Rock for Engineering Purposes’, December 2005 (Ref. 1).

General Notes The process of drilling and sampling will inevitably lead to disturbance, mixing or loss of material in some soils and rocks.

All depths are measured along the axis of the borehole and are related to ground level at the point of entry.

Made Ground (Fill) is readily identifiable when, within the material make up, manmade constituents are evident. Where the Made Ground (Fill) appears to be reworked natural material the differentiation between in situ natural deposits and Made Ground is much more difficult to ascertain. The interpretation of Made Ground (Fill) within the logs should therefore be treated with caution.

Coordinates and levels are based on the SCIRT Survey Specification, namely the Mount Pleasant Projection; January 2012, and the Christchurch City Council Drainage Datum; January 2012 (CCC DD) (Ref. 2).

For vertical nonoriented core ... “Dip” angle (eg. 5°) measured relative to horizontal For inclined nonoriented core ... “Angle” measured relative to core axis. For inclined oriented core ... “Dip” angle and “Dip Direction” angle (eg. 45°/225° mag.)

Standard Penetration tests have been carried out in general accordance with NZS 4402 Test 6.5.1. (Ref 3) N values are uncorrected. Refer to SPT Summary Table for blow count increments.

Shear Vane (NZGS 2005, Ref. 1, and NZGS 2001, Ref. 4). P Peak reading (kPa) R Residual reading (kPa)

Relative Density (Ref.1) VL Very Loose L Loose MD Medium Dense D Dense VD Very Dense

Consistency Terms for Cohesive Soils (Ref.1) VS Very Soft S Soft F Firm St Stiff VSt Very Stiff H Hard

Core & Rock Terms TCR Total Core Recovery as percentage (%) of core run. SCR Solid Core Recovery as percentage (%) of core run. Note: assessment of solid core is based on full diameter. RQD Rock Quality Designation. The amount of solid core greater than 100mm expressed as percentage (%) of core run.

Where SPT has been carried out at beginning of core run, disturbed section of core excluded from SCR and RQD assessment.

Defect spacing Fracture spacing (in millimetres), the minimum, average and maximum values are given. NI non‐intact core NA not applicable NR not recorded

Standard Penetration Test (SPT) S = 4 Split spoon sampler followed by SPT ‘N’ value C = 4 Solid cone followed by SPT ‘N’ value *300 Where full test drive not completed, linearly extrapolated N value reported (Ref. CIRIA Report 143, 1995, (Ref. 5)) Extrapolated N Value, N*=300 x (blows during test drive/penetration during test drive) ** No effective penetration

Sample type B Bulk disturbed sample C (incl. rotary, dynamically driven and rotosonic samples) D Small disturbed sample ES Environmental soil sample EW Environmental water sample P Piston sample U Undisturbed sample open drive W Water sample

References 1. The New Zealand Geotechnical Society, ‘Field Description of Soil and Rock – Guideline for the Field Classification and Description of Soil and Rock for Engineering Purposes’, December 2005. 2. SCIRT, ‘Survey Specification – Asset Assessment & Detailed Design, Revision 2.1’, 17 Jan 2012. 3. New Zealand Standards, ‘NZS 4402 Test 6.5.1 Determination of the Penetration Resistance of a Soil’, 1988. 4. The New Zealand Geotechnical Society, ‘Guideline for Hand Held Shear Vane Test’, 2001. 5. CIRIA Report 143, ‘The Standard Penetration Test (SPT): methods and use’, 1995.

SCIRT Key Sheet NEW gint rev 01 Page 1 of 2 October 2012 BH 59172 Stronger Christchurch Infrastructure Rebuild Team

1 Magdala Place, Middleton PO Box 9341, Tower Junction, Christchurch 8149

Sample Type Graphic

Core sample (C) Other samples (B, D, ES, EW, P, U, W)

Instrumentation

Standpipe (plain) Bentonite Bitumen

Standpipe (slotted) Gravel Sand

Cuttings (incl arisings Grout Concrete and collapsed material)

Stratum boundaries _____ Well defined boundary Grading boundary Estimated boundary

Graphic Log Symbols The graphic log shows the main components of soil and rock substances, represented by graphical symbols. Natural soils are generally a combination of constituents, eg sandy CLAY. Additional symbols may be allocated for a particular project. Symbols may be combined.

Made Ground (Fill) Clay Silt

Sand Gravel Breccia

Igneous (fine grained) Peat Pyroclastic (volcanic ash)

No core recovery (soil/rock type unknown)

Water Strike Where observed, details of water strikes are recorded. The process of drilling (addition of casing and drilling fluids), along with soil type, can mask the true water table.

Initial water strike Level water rose to

Where recorded, water levels within boreholes at the start and end of each shift are noted. In addition, for the hole progress, indicated water levels are those recorded during the progress of drilling in open or cased boreholes and may not represent standing water levels. Reference should be made to return groundwater monitoring data for standing water levels.

Moisture Condition D Dry M Moist W Wet S Saturated The moisture condition of soil is as observed during logging and may not represent the insitu moisture condition (ie the effect the drilling process has on the sample introduction of drill water etc.)

SCIRT Key Sheet NEW gint rev 01 Page 2 of 2 October 2012 BH 59172

Stronger Christchurch Infrastructure Rebuild Team 1 Magdala Place, Middleton, Christchurch, 8024 Job Number 11066 BOREHOLE LOG 11066-BH-02

PROJECT : Port Hills Area 4: Three Waters Design GROUND LEVEL (RL) : 17.89 m CDD SHEET : 1 OF 2 SITE : Port Hills Area EASTING : 392726.2 m SCALE : 1:25 START DATE : 02/12/2013 NORTHING : 802913.9 m DEPTH : 6 m END DATE : 02/12/2013 COORD. SYS. : MPP (Jan 2012)

SOIL / ROCK DESCRIPTION TEST DEPTH TYPE

(m) AND DETAILES

HOLE PROGRESS DATE TIME WATERvDEPTH LOG GRAPHIC CDD) RL (m DEPTH (m) SAMPLE TYPE GRAPHIC SAMPLE NO. AND TYPE FROM-TO (m) CASING DEPTH VALUE TCR (%) SCR (%) RQD (%) DEFECT SPACING MAX/AVG/MIN (mm) MOISTURE CONDITION CONSISTENCY / RELATIVE DENSITY WATER LEVEL 1 02/12/2013 Grass over SILT with minor clay, minor C1 0.00-1.00 09:00 rootlets (<1mm diameter) and trace to minor S to

gravel; dark brown. Soft to firm moist, Concrete F Toby box slightly plastic; gravel is fine, subangular to subrounded greywacke. (MADE GROUND) 17.54 0.35 M SILT with minor clay and trace rootlets (<1mm diameter); light brown. Firm, moist, Bentonite slightly plastic. (POSSIBLE MADE 95 F GROUND) 17.19 0.70 Fine SAND with minor silt; light brown. Loose; dry to moist.

D2 1.00-1.45 1.00 S = 3 C3 1.00-2.00 60

D L

D4 2.00-2.45 2.00 S = 3 C5 2.00-3.00 65

15.09 2.80 Sandy fine to coarse GRAVEL, tending to GRAVEL with some sand; grey. Medium dense; saturated. Gravel is subrounded 02/12/2013 greywacke. Sand is fine to coarse. D6 3.00-3.45 3.00 S = 26 Sand C7 3.00-4.00 2.80m-4.00m Medium dense. Walton Park

S MD 70

WATER STRIKE PIEZOMETER GENERAL COMMENTS STRIKE CASING TIME TO ROSE TO READING PLANT: Dando Terrier Rig (Geotechnics) ID DATE REMARKS DATE (m) DEPTH (m) RISE (min) (m) (m bgl) METHOD: Dynamic sampling 0.00m to 6.00m (sample 65mm diameter) 02/12/2013 3.13 CASING: 100mm diameter 0.00m to 6.00m SPT: Automatic Drop Hammer, reported energy ratio 75% PIEZOMETER INSTALLTION: 25mm diameter; screened from 1.00m to 5.40m BACKFILL: 6.45m to 5.40m heaving/collapse; 5.40m to 0.06m Walton Park sand; 0.06m to 0.20m bentonite; 0.20m to 0.00m concrete, toby box. REMARKS: Groundwater measured in installed piezometer 3.13m bgl on day of drilling. LOGGED BY: SJ CHECKED BY: TV CHECKED DATE: 17/02/2014 SCIRT LIB 1.02.GLB Log SCIRT BOREHOLE 11066- SCALAS.GPJ 19/Feb/2014 <> 15:21 8.30.003 Datgel Lab and In Situ - Photo - Fence and Map Tools | Lib V: SCIRT 1.02 2012-08-10 Prj V: SCIRT 1.02 2012-08-10 BH 59172

Stronger Christchurch Infrastructure Rebuild Team 1 Magdala Place, Middleton, Christchurch, 8024 Job Number 11066 BOREHOLE LOG 11066-BH-02

PROJECT : Port Hills Area 4: Three Waters Design GROUND LEVEL (RL) : 17.89 m CDD SHEET : 2 OF 2 SITE : Port Hills Area EASTING : 392726.2 m SCALE : 1:25 START DATE : 02/12/2013 NORTHING : 802913.9 m DEPTH : 6 m END DATE : 02/12/2013 COORD. SYS. : MPP (Jan 2012)

SOIL / ROCK DESCRIPTION TEST DEPTH TYPE

(m) AND PIEZOMETER DETAILES

HOLE PROGRESS DATE TIME WATERvDEPTH LOG GRAPHIC CDD) RL (m DEPTH (m) SAMPLE TYPE GRAPHIC SAMPLE NO. AND TYPE FROM-TO (m) CASING DEPTH VALUE TCR (%) SCR (%) RQD (%) DEFECT SPACING MAX/AVG/MIN (mm) MOISTURE CONDITION CONSISTENCY / RELATIVE DENSITY WATER LEVEL Sandy fine to coarse GRAVEL, tending to D8 4.00-4.45 4.00 S = 43 GRAVEL with some sand; grey. Medium C9 4.00-5.00 dense; saturated. Gravel is subrounded greywacke. Sand is fine to coarse. (continued) 4.00m-4.70m Dense. D 30

13.19 4.70 Fine to coarse SAND with minor gravel; D10 4.70-5.15 S = 28 grey. Saturated; gravel is fine to medium, undertaken 13.04 4.85 subrounded greywacke. in heaved material MD 4.70m-5.15m Medium dense. S Sandy fine to coarse GRAVEL, tending to C11 5.00-6.00 GRAVEL with some sand; grey. Saturated; gravel is subrounded greywacke; sand is fine to coarse. 35

12.24 5.65 Fine to coarse SAND; grey. Saturated.

12.14 5.75 Heave Fine to coarse GRAVEL, tending to Cuttings GRAVEL with some sand and trace silt; 02/12/2013 grey. Saturated; gravel is subrounded 14:00 greywacke; sand is fine to coarse. Hole Terminated at 6.00 m

WATER STRIKE PIEZOMETER GENERAL COMMENTS STRIKE CASING TIME TO ROSE TO READING PLANT: Dando Terrier Rig (Geotechnics) ID DATE REMARKS DATE (m) DEPTH (m) RISE (min) (m) (m bgl) METHOD: Dynamic sampling 0.00m to 6.00m (sample 65mm diameter) 02/12/2013 3.13 CASING: 100mm diameter 0.00m to 6.00m SPT: Automatic Drop Hammer, reported energy ratio 75% PIEZOMETER INSTALLTION: 25mm diameter; screened from 1.00m to 5.40m BACKFILL: 6.45m to 5.40m heaving/collapse; 5.40m to 0.06m Walton Park sand; 0.06m to 0.20m bentonite; 0.20m to 0.00m concrete, toby box. REMARKS: Groundwater measured in installed piezometer 3.13m bgl on day of drilling. LOGGED BY: SJ CHECKED BY: TV CHECKED DATE: 17/02/2014 SCIRT LIB 1.02.GLB Log SCIRT BOREHOLE 11066- SCALAS.GPJ 19/Feb/2014 <> 15:21 8.30.003 Datgel Lab and In Situ - Photo - Fence and Map Tools | Lib V: SCIRT 1.02 2012-08-10 Prj V: SCIRT 1.02 2012-08-10 Stronger Christchurch Infrastructure Rebuild Team

1 Magdala Place, Middleton PO Box 9341, Tower Junction, Christchurch 8149

SPT Test Summary Tables BH 59172 Project: Port Hills Three Waters Job Number: 11066 Borehole 11066-BH-01 Seating Blow Test Range

Water 1 2 3 4 5 6 Uncorrected 'N' Depth - Top Casing (m Borehole Type Level (m Pen. Pen. Pen. Pen. Pen. Pen. ValueEnergy Comments (m BGL) BGL) Count Count Count Count Count Count BGL) (mm) (mm) (mm) (mm) (mm) (mm) ratio/efficiency 75.95% 1.00 S 1.00 0 75 0 75 1 75 0 75 0 75 0 75 1 2.00 S 2.00 0 75 0 75 0 75 0 75 0 75 0 75 <1 3.00 S 3.00 0 75 0 75 0 75 0 75 0 75 0 75 <1 4.00 S 4.00 0 75 0 75 0 75 0 75 0 75 0 75 <1 11066-BH-01 NR 5.00 S 5.00 0 75 0 75 0 75 0 75 0 75 0 75 <1 6.00 S 6.00 0 75 0 75 0 75 0 75 0 75 0 75 <1 7.00 S 7.00 0 75 0 75 0 75 0 75 1 75 1 75 2 8.00 S 8.00 1 75 1 75 1 75 1 75 1 75 1 75 4

Borehole 11066-BH-02 Seating Blow Test Range Water 1 2 3 4 5 6 Uncorrected 'N' Depth - Top Casing (m Borehole Type Level (m Pen. Pen. Pen. Pen. Pen. Pen. ValueEnergy Comments (m BGL) BGL) Count Count Count Count Count Count BGL) (mm) (mm) (mm) (mm) (mm) (mm) ratio/efficiency 75.95% 1.00 S 1.00 0 75 0 75 0 75 1 75 1 75 1 75 3 2.00 S 2.00 1 75 1 75 0 75 1 75 1 75 1 75 3 11066-BH-02 3.00 S 3.00 NR 3 75 5 75 6 75 7 75 6 75 7 75 26 4.00 S 4.00 1 75 9 75 11 75 11 75 11 75 10 75 43 4.70 S 5.15 1 75 1 75 4 75 6 75 8 75 10 75 28 Test not reliable due to 300mm heave

Borehole 11066-BH-03 Seating Blow Test Range Water 1 2 3 4 5 6 Uncorrected 'N' Value Depth - Top Casing (m Borehole Type Level (m Pen. Pen. Pen. Pen. Pen. Pen. Energy ratio/efficiency Comments (m BGL) BGL) Count Count Count Count Count Count BGL) (mm) (mm) (mm) (mm) (mm) (mm) 91.2% 1.50 S 1.50 1 75 0 75 0 75 0 75 1 75 0 75 1 3.00 S 3.00 0 75 0 75 1 75 0 75 0 75 1 75 2 11066-BH-03 4.50 S 4.50 NR 0 75 1 75 1 75 0 75 0 75 1 75 2 6.00 S 6.00 4 75 20 75 17 75 13 75 15 75 5 15 >50 50 blows for 240mm penetration 7.50 S 7.50 5 75 13 75 22 75 28 60 >50 50 blows for 135mm penetration

Notes: NR = Not Recorded S = Split Spoon C = Cone BH 59172 Port Hills Area 4 Three Waters Design Ground Investigation – Factual Report

Borehole: 11066BH02

Depth: 0.00m 6.00m

Date: 02/12/2013

Borehole 11066BH02, 0.00m 0.20m BH 59172

Port Hills Area 4 Three Waters Design Ground Investigation – Factual Report

Borehole 11066BH02, 1.00m 2.00m

Borehole 11066BH02, 2.00m 3.00m BH 59172

Port Hills Area 4 Three Waters Design Ground Investigation – Factual Report

Borehole 11066BH02, 3.00m 4.00m

Borehole 11066BH02, 4.00m 5.00m BH 59172

Port Hills Area 4 Three Waters Design Ground Investigation – Factual Report

Borehole 11066BH02, 5.00m 6.00m Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

Appendix C CPT Logs

CPT 201 CPT 209 CPT 648 CPT 649 CPT 6319 CPT 8122 CPT 17188 CPT 21150 CPT 40390 CPT 59166 CPT 59205 CPT 59206

Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

Appendix D Hand Auger / DCP Logs

HA 60205 HA 47258

HA 47258

HA02

SP04

HA01

SP03

= Test Location Note: All images sourced from Google Maps

Oct-14Sep- Date Client Arrow International (NZ) Ltd 14

Drawn by EG/RP Project Southern Response

Approved by GM Description Site Location Plan

Scale NTS Geoscience Ref. 9653.000.2538 Client Ref. D3426738 09-15-2014 Z:\Projects\Project - 9600 to 9700\9653 Southern Response\7_TC3 Sites\D3426738_2B Wherstead Road\HA01.bor Dip testshowedstanding waterat2.3mdepth. Hand augerandScalaPenetrometer mettargetdepthat3.0mdepth. Termination: TargetDepth 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Depth (m)

ALLUVIUM TOPSOIL Material ML ML SP 2B WhersteadRoad USCS Symbol EOH: 3.0m Poorly graded,subroundedtosubangular. Fine tomediumSANDwithtracesilt;grey Becomes darkgreyat2.0mdepth. poorly graded. encountered from1.7mdepth.Sand,fine, Becomes saturatedandminorsand plasticity. SILT; greywithorangemottles.Low brown. Lowplasticity[TOPSOIL]. SILT withtracesand,gravelandrootlets; Cashmere D3426738 DESCRIPTION Hole Diameter Drilling Method Geoscience Ref. Project Client HAND AUGERBOREHOLE-HA01 : 50mm : Handauger : 9653.000.2538 : SouthernResponse : ArrowInternational(NZ)Ltd

Graphic Log

Water Level W M S Moisture Condition Shear Vane(kPa) Peak/Remolded 124/29 114/24 84/22 223+ UTP Reviewed By Logged By Shear VaneNo. Hole Depth Date St-VSt V St-H H D Consistency /

Density Index (Page 1of2) 0 Scala Penetrometer Blows per100mm 2 : LF : EG/RP : 1379 : 3.0m : 12/09/14 4 HA 47258 6 8 10 12 14 HA 47258

Scala Penetrometer Testing

Client: Arrow International (NZ) Ltd Geoscience ref: 9653.000.2538 Project: Southern Response Client ref: D3426738 Site address: 2B Wherstead Road, Cashmere Date: 12/09/2014 Location: Refer to Site Location Plan By: EG/RP Test No. HA01 Test No. HA02 Test No. SP03 Test No. SP04 Depth (mm) Blows Depth (mm) Blows Depth (mm) Blows Depth (mm) Blows 100 1 100 1 100 1 100 1 200 1 200 1 200 1 200 2 300 1 300 1 300 3 300 11 400 3 400 3 400 2 400 16 500 4 500 4 500 5 500 6 600 3 600 3 600 3 600 2 700 2 700 2 700 3 700 3 800 4 800 4 800 4 800 4 900 3 900 3 900 4 900 3 1000 4 1000 4 1000 5 1000 5 1100 5 1100 5 1100 5 1100 4 1200 4 1200 4 1200 6 1200 6 1300 4 1300 4 1300 7 1300 8 1400 4 1400 4 1400 7 1400 10 1500 3 1500 3 1500 7 1500 7 1600 2 1600 2 1600 10 1600 4 1700 2 1700 2 1700 9 1700 6 1800 2 1800 2 1800 9 1800 6 1900 2 1900 2 1900 7 1900 5 2000 1 2000 1 2000 7 2000 5 2100 1 2100 1 2100 8 2100 5 2200 2 2200 2 2200 9 2200 7 2300 7 2300 7 2300 10 2300 9 2400 8 2400 8 2400 9 2400 11 2500 5 2500 5 2500 9 2500 10 2600 8 2600 8 2600 11 2600 10 2700 9 2700 9 2700 14 2700 2800 10 2800 10 2800 15 2800 2900 9 2900 9 2900 2900 3000 10 3000 3000 3000 3100 3100 3100 3100 3200 3200 3200 3200 3300 3300 3300 3300 3400 3400 3400 3400 3500 3500 3500 3500 3600 3600 3600 3600 3700 3700 3700 3700 3800 3800 3800 3800 3900 3900 3900 3900 4000 4000 4000 4000 HA 60205

Geotechnical Investigation – 52 Colombo Street, Cashmere (D4148966) 2

Figure 1: Site Location Plan and Investigation Locations

N

HA04 HA03

HA02 HA01

All images sourced from Google Maps

04.06.2015 9653.000.234 _01Rev1 HA 60205

LOG OF HAND AUGER HA01

Southern Response Client : Arrow International Ltd Shear Vane No : 1150 52 Colombo Street Client Ref. : D4148966 Logged By : RP/DG Cashmere Date : 04/09/14 Reviewed By : LF Hole Depth : 2.2 m Latitude : -43.562738 9653.000.2340 Hole Diameter : 50 mm Longitude : 172.637184

Shear Vane Scala Penetrometer Undrained Shear DESCRIPTION Strength (kPa) Peak/Remolded Blows per 100mm

Depth (m) Depth Material USCS Symbol Symbol Graphic Level Water Cond. Moisture Consistency/ Index Density 2 4 6 8 10 12 SILT with minor sand, trace charcoal, brick and rootlets; brown. Low plasticity. Sand, fine to S-F

TS ML medium, poorly graded, subrounded to subangular [TOPSOIL]. Fine to medium SAND; greyish brown. Poorly graded, subrounded to subangular. 0.5

VL-L 1.0 W SP ALLUVIUM

1.5 Orange mottles encountered from 1.5 m to 2.1 m depth.

L-MD 2.0

Becomes grey and trace gravel encountered D from 2.1 m depth. >> End of Hole Depth: 2.2 m Termination Condition: Practical refusal

2.5

3.0

3.5

Hand auger met practical refusal at 2.2 m depth on gravel. Scala Penetrometer met practical refusal at 2.2 m depth. Groundwater not encountered. TS = TOPSOIL GEOSCIENCE HAND AUGER HA TEMPLATE- SOUTHERN RESPONSE.GPJ DATA TEMPLATE NZ 2.GDT 10/9/14 Colombo Street and Beckenham Street Wastewater Geotechnical Assessment Report

Appendix E MWH Factual Geotechnical Report

GEOTECHNICAL FACTUAL REPORT

COLOMBO BECKENHAM ST WASTEWATER Prepared for Christchurch City Council December 2016

Colombo Beckenham St WW

This document has been prepared for the benefit of Christchurch City Council. No liability is accepted by this company or any employee or sub-consultant of this company with respect to its use by any other person.

This disclaimer shall apply notwithstanding that the report may be made available to other persons for an application for permission or approval to fulfil a legal requirement.

QUALITY STATEMENT

PROJECT MANAGER PROJECT TECHNICAL LEAD Chris Maguire Steph Thompson

PREPARED BY Daniel Goodman ………………………………...... ……/……/…… CHECKED BY Matthew Shore ………………………………...... ……/……/…… REVIEWED BY Steph Thompson ………………………………...... ……/……/…… APPROVED FOR ISSUE BY Chris Maguire ………………………………...... ……/……/……

CHRISTCHURCH Hazeldean Business Park, 6 Hazeldean Road, Addington, Christchurch 8024 PO Box 13-052, Armagh, Christchurch 8141 TEL +64 3 366 7449, FAX +64 3 366 7780

REVISION SCHEDULE

Signature or Typed Name (documentation on file) Rev Date Description No. Prepared Checked Reviewed Approved by by by by 1 15/11/2016 Final DG MS

Status: Final December 2016 Project No.: 80508773 Our ref: Colombo Beckenham Factual Report Colombo Beckenham St WW

Christchurch City Council Colombo Beckenham St WW Geotechnical Factual Report

CONTENTS 1 Introduction ...... 1 2 Site Information ...... 1 2.1 Proposed Development ...... 1 2.2 Site Location ...... 1 2.3 Site Description ...... 2 2.4 Existing Geotechnical Information ...... 2 3 Published Geology ...... 2 4 Site Investigations ...... 3 4.1 Introduction ...... 3 4.2 Borehole ...... 4 4.3 Groundwater ...... 4 5 Conclusion ...... 5 6 Limitations ...... 6 7 References ...... 7

Status: Final December 2016 Project number: 80508773 Our ref: Colombo Beckenham Factual Report Colombo Beckenham St WW

LIST OF TABLES Table 4-1: Summary of Borehole ...... 4 Table 4-2: Summary of Soil Profile from Borehole Investigations ...... 4 Table 4-3: Summary of Groundwater Level Monitoring ...... 4

LIST OF FIGURES Figure 2-1: Proposed Colombo St syphon location between Waimea Tce and Hunter Tce...... 1 Figure 2-2: Photograph of low connecting to the true left abutment of Colombo St Bridge on the downstream side...... 2 Figure 3-1: Site Geology, (GNS 1:25,000 Geological Map 1 – Christchurch Urban Area, 1992) ...... 3

APPENDICES Appendix A Geotechnical Investigation Plan and River Cross-section Appendix B Borehole Logs and Core Sample Photos

Status: Final December 2016 Project number: 80508773 Our ref: Colombo Beckenham Factual Report Colombo Beckenham St WW

1 Introduction

MWH New Zealand Limited (MWH) has been engaged by Christchurch City Council to undertake detailed design of an upgrade to the waste water network on Colombo Street and Beckenham Street. The upgrade is to alleviate wastewater overflows from the PS20 catchment during the 3 year ARI, 24 hour design storm. The current design includes a syphon under the Heathcote River between Hunter Terrace and Waimea Terrace, which is to be installed using trenchless construction. A round of site investigations were commissioned at the site to inform detailed design and provide information to allow an appropriate trenchless construction method to be selected by the Contractor. This Geotechnical Factual Report outlines the findings of the site investigations and presents the raw data collected. 2 Site Information

2.1 Proposed Development

Refer to the Preliminary Design Report dated October 2016 and Preliminary Drawings CP502816/D C100 – C105 for details of the proposed upgrade. 2.2 Site Location

The syphon is to be located below the Heathcote River between Waimea Terrace and Hunter Terrace, immediately to the east of the bridge on Colombo St. Waimea Terrance and Hunter Terrace are both low volume Access Roads, while Colombo St is classified as a Primary Collector Route. The Christchurch City Council Beckenham Service Centre is located on the south side of Hunter Terrace, near the southern bank of the Heathcote River.

Proposed syphon alignment

Figure 2-1: Proposed Colombo St syphon location between Waimea Tce and Hunter Tce.

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2.3 Site Description

The bed level of the Heathcote River at the location of the proposed syphon is approximately 3 metres below neighbouring ground level (see Appendix A). The banks of the river over this section vary between 4H:1V and 1H:1V. There is a short retaining wall located approximately half way up the northern river bank downstream of the bridge supporting the pavement of Waimea Tce as it meets Colombo St. The retaining wall is approximately 1.0 m in height and has been constructed from irregularly shaped blocks of mass concrete (see Figure 2-2). The southern bank is moderately vegetated and the northern bank is heavily vegetated.

Figure 2-2: Photograph of low retaining wall connecting to the true left abutment of Colombo St Bridge on the downstream side.

2.4 Existing Geotechnical Information

There is a considerable volume of geotechnical information available, via the New Zealand Geotechnical Database (NZGD), for sites within the vicinity of the project area. A full catalogue of the geotechnical information from the NZGD relevant to the project has been included in the MWH Geotechnical Assessment Report dated July 2016 as Appendix B, C and D. 3 Published Geology

The geology of the site, as published in the GNS 1:25,000 Geological Map of Christchurch Urban Area (1992), is “dominantly alluvial sand and silt over bank deposits” belonging to the Yaldhurst Member of the Springston Formation as shown in Figure 3-1. This is a relatively recent formation, understood to be deposited during the Holocene epoch, which underlain at depth with older alluvium formations. On the larger, more recent 1:250,000 Geological Map of Christchurch (2000), the geology at the site is described as “grey river alluvium beneath plains or low-level terraces” (Q1a). Based on knowledge of the region is likely to be basaltic to trachytic lava flows similar to the Lyttelton Volcanic Group located at significant depth (>100 m).

Status: Final December 2016 Project No.: 80508773 Page 2 Our ref: Colombo Beckenham Factual Report Colombo Beckenham St WW

Proposed Syphon Location

Figure 3-1: Site Geology, (GNS 1:25,000 Geological Map 1 – Christchurch Urban Area, 1992)

4 Site Investigations

4.1 Introduction

Site investigations were undertaken on 10 November 2016. Investigations involved drilling two sonic boreholes, one on each side of the river at the approximate location of the proposed syphon manholes (see Figure 2-1). Insitu testing was limited to Standard Penetration Tests (SPT’s) at 1 metre intervals; however, a push tube sample was taken within a layer of fine grained material to allow laboratory testing to be undertaken at a later date if required.

Drilling and insitu tests were supervised by a Geotechnical Engineer from MWH and were logged in accordance with the Guidelines for the Field Classification of Soil and Rock for Engineering Purposes, (New Zealand Geotechnical Society, 2005). Machine boreholes were located away from any known services (based on service plans) and each investigation location was surveyed with ground penetrating radar (GPR) prior to commencement of drilling. All references to elevations are with respect to the Christchurch Drainage Datum (CDD) and coordinates are with reference to the New Zealand Transverse Mercator 2000 (NZTM2000) projection.

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4.2 Borehole

The upper 1.2 m of material at each borehole location was removed using hydro-excavation to prevent damage to any services that were not identified using the GPR. The boreholes were advanced by ProDrill using a sonic drilling technique and SPT’s were performed at 1.0 m intervals over the entire length of each. Details of the borehole investigation are outlined in Table 4-1 below. The borehole log and photos of retrieved core samples are presented in Appendix B. Table 4-1: Summary of Borehole Maximum Borehole Surface Piezometer depth Date Drilled Core Size ID RL (m RL) Installed (m bgl) BH01 16 10.45 10/11/2016 Yes PQ BH02 16 10.45 10/11/2016 Yes PQ

The material encountered within the two boreholes was largely silt and sand with gravel and organic matter content varying with depth. Material within the upper 2.6 m of BH01 and 1.45 m of BH02 was believed to be construction demolition material placed as fill due to the presence of whole bricks, crushed concrete and glass fragments. See Table 4-2 for a summary of the material encountered and its relative layering. Table 4-2: Summary of Soil Profile from Borehole Investigations

Depth (m bgl) Layer BH01 BH02 Uncontrolled FILL 0 – 2.6 1 – 1.45 SILT with Organics - 1.45 – 2.3 Sandy GRAVEL/Gravelly SAND 2.6 – 4.0 2.3 – 4.1 Clayey SILT with Organics 4.0 – 7.0 4.1 – 8.5 SILT and Fine SAND 7.0 – 10.45 8.5 – 10.45

The standpipe piezometer installations consist of a 50 mm diameter PVC pipe, threaded and sealed. The slotted section was installed between 5.5 m and 10.0 m below ground level, surrounded by free draining gravel. Above and below the slotted section, 1.0 m of bentonite pellets were placed to provide an impermeable barrier to vertical flow within the borehole excavation. The remaining length of solid PVC pipe to the surface was backfilled with sand/gravel, with an additional bentonite layer between 0.5 and 1.0 m bgl. A lockable flush toby was installed at the surface. A diagrammatic summary of the piezometer installation is presented in the borehole logs located within Appendix B. 4.3 Groundwater

The groundwater level within each piezometer was measured at the time of drilling and approximately a week after drilling had been completed. See Table 4-3 for a summary of measurements. Table 4-3: Summary of Groundwater Level Monitoring Time Depth in Depth in Comments Date BH01 (m bgl) BH02 (m bgl) 10/11/2016 12.30 pm 1.34 - At time of drilling 10/11/2016 4.20 pm 1.23 0.5 At time of drilling 21/11/2016 3.00 pm 1.34 1.23 10 days after drilling

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5 Conclusion

MWH NZ Limited (MWH) has been engaged by Christchurch City Council to undertake a site investigation and prepare a Geotechnical Factual Report of the ground conditions at the site of the proposed wastewater syphon under the Heathcote River adjacent to Colombo St. Two sonic boreholes were drilled on 10 November 2016, with Standard Penetration Tests under taken at 1 m intervals. Groundwater levels were also recorded over a week after drilling once the local groundwater table has equalised from the effects of the drilling. The primary observations were that material below the base of the river channel is largely silt and fine sand with organics, and that the upper 1.45-2.6 m of the river banks are constructed from uncontrolled fill.

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6 Limitations

This report has been prepared for the Christchurch City Council in accordance with the generally accepted practices and standards in use at the time it was prepared. MWH accepts no liability to any third party who relies on this report. The information contained in this report is accurate to the best of our knowledge at the time of issue. MWH has made no independent verification of this information beyond the agreed scope set out in the report. The type, spacing and frequency of the investigations, sampling, and testing of materials were selected to meet the technical, financial and time requirements agreed by the client. MWH accepts no liability for any unknown or adverse ground conditions. Actual ground conditions encountered during site works may vary from those encountered during ground investigations. For example, subsurface groundwater conditions often change seasonally and over time. No warranty is expressed or implied that the actual conditions encountered will conform exactly to the conditions described herein. This report does not purport to describe all the site characteristics and properties. Subsurface conditions and testing relevant to construction works must be undertaken and assessed by any contractors as necessary for their own purposes.

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7 References

1. Begg, J.G; Johnston, M.R. (compilers) 2000. Geology of the Wellington area. Institute of Geological and Nuclear Sciences 1:250 000 geological map 10. 64 p. Lower Hutt, New Zealand: Institute of Geological and Nuclear Sciences Limited.

2. Brown, L.j.: Weeber, J.H. 1992: Geology of the Christchurch urban area. Scale 1:25 000. Institute of Geological & Nuclear Sciences geological map 1. Institute of Geological & Nuclear Sciences Limited, Lower Hutt, New Zealand.

3. New Zealand Geotechnical Society, 2005, Guideline for the Field Classification and Description of Soil and Rock for Engineering Purposes.

Status: Final December 2016 Project No.: 80508773 Page 7 Our ref: Colombo Beckenham Factual Report

Appendices

Colombo Beckenham St WW

Appendix A Geotechnical Investigation Plan and River Cross-section

Status: Final December 2016 Project No.: 80508773 Page 1 Our ref: Colombo Beckenham Factual Report

re

EN Fib EN EN /

/ / Fib EN / Fib Fib

re

re re

BH 01

re

Fib

/ EN

re

EN

Fib

EN /

/ EN Fib

/ EN

Fib /

re Fib

re

re LEGEND

re

Fib /

EN BORE HOLELOCATION EN BH 02 re

EN / Fib Fib

/ EN

/ re Original size mm Fib EN

/ Fib

re

300

re

re

Fib

/ CPT LOCATION EN

EN

re / Fib

EN

Fib

re / EN /

Fib

EN

/

Fib

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re re

/Fib EN EN

/

EN Fib

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/

Fib re

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/ re

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/

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re Fib re / EN Fib

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EN Fib re /

EN

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EN

Fib / re EN

re re Fib / EN EN re Fib

/ re

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/ Fib

/ /

Fib EN EN

EN /Fibre

re re

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/ Fib

/ EN

EN re

/Fibre EN EN

/ Fib

re

re

/

EN Fib /Fibre EN

EN

/ Fib

EN / re Fib re Fib re / re

EN re EN Fib

EN /Fibre EN /Fibre / / Fib

EN /Fibre EN EN

re Fib / EN / EN re NOTES Fib / CPT 59205 CPT 59206 re EN /Fibre EN /Fibre EN /Fibre DNEN / Fib225re Fib re 1. REFER TO DRG G002 FOR GENERAL NOTES

EN 2. CONTRACTOR TO CONFIRM RIVER BED /

Fib LEVEL PRIOR TO CONSTRUCTION re COMMENCING

EN 3. GROUNDWATER LEVELS RECORDED 1 / Fib WEEK AFTER DRILLING AND DO NOT

re NECESSARILY REFLECT SEASONAL

200 EN

/ Fib AVERAGE

re 4. REFER TO MWH GEOTECHNICAL DN 300 ASSESSMENT REPORT DATED DECEMBER

EN 2016 FOR INVESTIGATION DATA. / Fib

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/

Fib EN

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EN EN

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Fibre EN /Fibre DN 225

/ Fib re

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/ Fib

Fib / EN EN

re

re / Fib re Fib / EN EN EN re Fib /

re Fib / EN 150 PLAN SCALE 1:200

EXISTING RETAINING WALL DEPTH BH 01 SPT N VALUE SPT N VALUE (UNCORRECTED) (UNCORRECTED) DEPTH BH 02 100

FILL FILL

1.23 1.34 1.45m ? ? 32 SILT with some 1 clay ? ? 2.0m STREAMBED SEDIMENT 50 2.3m ? ? ? ? PEAT 2.6m 27 sandy GRAVEL 27

30 sandy GRAVEL 3.3m gravelly SAND 4.0m 6 4.1m ? ? ? ? ? ? ? ? ? ? ? 2 10 0

4 clayey SILT with 5 organics and wood SILT with wood 1 and minor clay 1 1 ? 7.0m ? ? SAND with ? minor silt ? ? ? 2 ? 8.0m 3 ? ? 8.5m ? 6 sandy SILT to 4 sandy SILT to silty SAND silty SAND 6 2

LONGITUDINAL SECTION H 1:50 V 1:50

‹&23<5,*+7&+5,67&+85&+&,7<&281&,/?$(5,$/3+272*5$3+<‹&23<5,*+77(55$/,1.,17(51$7,21$//,0,7(' ISSUE AMENDMENTS SIGNED DATE

DATUM C.D.D. NAME SIGNED DATE CONSULTANT PROJECT TITLE DRAWING TITLE CONTRACT NUMBER ORIGINAL SCALES APPROVED SHEET BENCH MK. DESIGNED S THOMPSON 12/2016 FOR TENDER CN4600001677 SIZE H 1:500 RL DES. REVIEW DATE SIGNED CAD DRAWING FILE REF. SURVEY DRAWN PAUL CHILTON 12/2016 CHRISTCHURCH CITY COUNCIL GEOTECHNICAL C400 A1 V 1:100 SURVEY LB DRW. CHECK FOR CONSTRUCTION COLOMBO ST AND BECKENHAM ST INVESTIGATIONS CPG PROJECT FILE NUMBER SHEET DATE SIGNED DRAIN. REF. CONSULTANT PROJECT REF. CONSULTANT FILE REF. OF C400 CP502816/D SAP WBS PRINTED ON $DATE$ BY $USERNAME$ Colombo Beckenham St WW

Appendix B Borehole Logs and Core Sample Photos

Status: Final December 2016 Project No.: 80508773 Page 2 Our ref: Colombo Beckenham Factual Report MWH SITE INVESTIGATION LEGEND Project Name: Colombo Beckenham St Wastewater Upgrade Number: 80508773

Graphic Log Key: Logging Standards: Field Descriptions of Soils and Rocks. New Zealand Geotechnical Society, 2005. CLAYST Silty Clay Determination of Penetration Resistance of a Soil, NZS 4402: 1988, Test 6.5.2

FILL Fill (made ground)

GRAVELSD Sandy Gravel

SAND Sand

SANDGR Gravelly Sand

SANDST Silty Sand

SILT Silt

SILTSD Sandy Silt

TOPSOIL Topsoil

Installation Type Key:

Solid TUBE in SAND SAND only (SAND) (TSAND) m St Wastewater Upgrade, Banks of the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz its intersection the Heathcote River at Upgrade,m St Wastewater Banks of

Solid TUBE in Slotted TUBE in SAND BENTONITE SEAL (TSSAND) (TBENT)

Solid TUBE in CONCRETE (TCONC)

Solid TUBE in GRAVEL (TGRAV) 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenha NZ GEOTECHNICAL SOCIETY INC > fi eld guide sheet ROCK FIELD DESCRIPTION OF ROCK SEQUENCE OF TERMS – weathering – colour – fabric – rock name – strength – discontinuities – additional SCALE OF ROCK MASS WEATHERING Term Abbreviation Description Unweathered I UW Rock mass shows no loss of strength, discolouration or other effects due to weathering. There may be slight (fresh rock) discolouration on major rock mass defect surfaces or on clasts. Slightly II SW The rock mass is not signifi cantly weaker than when fresh. Rock may be discoloured along defects, some of which Weathered may have been opened slightly. Moderately III MW The rock mass is signifi cantly weaker than the fresh rock and part of the rock mass may have been changed to a Weathered soil. Rock material may be discoloured and defect and clast surfaces will have a greater discolouration, which also penetrates slightly into the rock material. Increase in density of defects due to physical disintegration. Highly IV HW Most of the original rock mass strength is lost. Material is discoloured and more than half the mass is changed Weathered to a soil by chemical decomposition or disintegration (increase in density of defects/fractures). Decomposition adjacent to defects and at the surface of clasts penetrates deeply into the rock material. Lithorelicts or corestones of unweathered or slightly weathered rock may be present. Completely V CW Original rock strength is lost and the rock mass changed to a soil either by decomposition (with some rock fabric Weathered preserved) or by physical disintegration. Residual Soil VI RS Rock is completely changed to a soil with the original fabric destroyed (pedological soil). ROCK STRENGTH TERMS Term Field Identification of Specimen Unconfined uniaxial Point load strength

compressive strength qu (MPa) Is(50) (MPa) Extremely strong Can only be chipped with geological hammer > 250 >10 Very strong Requires many blows of geological hammer to break it 100 – 250 5 – 10 Strong Requires more than one blow of geological hammer to fracture it 50 – 100 2 – 5 Moderately strong Cannot be scraped or peeled with a pocket knife. Can be fractured with single 20 – 50 1 – 2 fi rm blow of geological hammer Weak Can be peeled by a pocket knife with diffi culty. Shallow indentations made 5 – 20 by fi rm blow with point of geological hammer Very weak Crumbles under fi rm blows with point of geological hammer. Can be 1 – 5 <1 peeled by a pocket knife Extremely weak Indented by thumb nail or other lesser strength terms used for soils <1 (soil description required)

Note: • No correlation is implied between qu and Is(50) SPACING OF DEFECTS/ DISCONTINUITIES BEDDING THICKNESS TERMS ROUGHNESS AND APERTURE Term Spacing Term Bed Thickness Very widely spaced >2 m Thinly laminated < 2 mm Widely spaced 600 mm – 2 m Laminated 2 mm - 6 mm Moderately widely spaced 200 mm – 600 mm Very thin 6 mm - 20 mm Closely spaced 60 mm – 200 mm Thin 20 mm - 60 mm Very closely spaced 20 mm – 60 mm Moderately thin 60 mm - 200 mm Extremely closely spaced <20 mm Moderately thick 0.2 m - 0.6 m Thick 0.6 m - 2 m APERTURE OF DISCONTINUITY SURFACES Very thick > 2 m Term Aperture (mm) Description BEDDING INCLINATION TERMS

Tight Nil Closed Term Inclination (from horizontal) MUSCHAMP KARRYN Very Narrow > 0 – 2 Sub-horizontal 0° – 5° design Narrow 2 – 6 Gently inclined 6° – 15° Moderately Narrow 6 – 20 Gapped Moderately inclined 16° – 30°

Moderately Wide 20 – 60 Open Steeply inclined 31° – 60° WILLIAMS KATE Wide 60 – 200 Very steeply inclined 61° – 80° Very Wide > 200 Sub-vertical 81° – 90° compiled by

This fi eld sheet has been taken from and should be used and read with reference to the document FIELD NZ GEOTECHNICAL DESCRIPTION OF SOIL AND ROCK. Guideline For the Field Classifi cation and Description of Soil and Rock SOCIETY INC for Engineering Purposes. NZ Geotechnical Society Inc, December 2005. www.nzgeotechsoc.org.nz NZ GEOTECHNICAL SOCIETY INC

> fi eld guide sheet SOIL FIELD DESCRIPTION OF SOIL SEQUENCE OF TERMS – fraction – colour – structure – strength – moisture – bedding – plasticity – sensitivity – additional

GRAIN SIZE CRITERIA

COARSE FINE ORGANIC SOIL Gravel Sand CLASSIFICATION TYPE Boulders Cobbles Silt Clay Organic Soil fi n e fi n e coarse coarse medium medium

Size Range 200 60 20 6 2 0.6 0.2 0.06 0.002 (mm) Particle size Particle Graphic composition Symbol

PROPORTIONAL TERMS DEFINITION (COARSE SOILS) Fraction Term % of Soil Mass Example MATERIAL Fraction fi ner fi Fraction Major (.…) ≥ 50 GRAVEL than 0.06mm [UPPER CASE] [major constituent]

Subordinate (….) y 20 – 50 Sandy SOIL COARSE behaviour >35% <35% [lower case] Quick/dilatant Minor with some … 12 – 20 with some sand with minor … 5 – 12 with minor sand FINE SOIL

with trace of (or slightly)… < 5 with trace of sand Plastic CLAY SILT SAND GRAVEL COBBLES BOULDERS SAND GRAVEL SILT CLAY (slightly sandy) behaviour DENSITY INDEX (RELATIVE DENSITY) TERMS CONSISTENCY TERMS FOR COHESIVE SOILS Descriptive Density Index SPT “N” value Dynamic Cone Descriptive Undrained Shear Diagnostic Features Term (RD) (blows / 300 mm) (blows / 100 mm) Term Strength (kPa) Very dense > 85 > 50 > 17 Very soft < 12 Easily exudes between fi ngers when squeezed Dense 65 – 85 30 – 50 7 – 17 Soft 12 – 25 Easily indented by fi ngers Medium dense 35 – 65 10 – 30 3 – 7 Firm 25 – 50 Indented by strong fi nger pressure and Loose 15 – 35 4 – 10 1 – 3 can be indented by thumb pressure Very loose < 15 < 4 0 – 2 Stiff 50 – 100 Cannot be indented by thumb pressure Note: • No correlation is implied between Standard Penetration Test (SPT) and Dynamic Cone Test values. • SPT “N” values are uncorrected. • Dynamic Cone Penetrometer (Scala) Very stiff 100 – 200 Can be indented by thumb nail ORGANIC SOILS/ DESCRIPTORS Hard 200 – 500 Diffi cult to indent by thumb nail

Term Description MOISTURE CONDITION Topsoil Surfi cial organic soil layer that may contain living Condition Description Granular Soils Cohesive Soils matter. However topsoil may occur at greater depth, having been buried by geological processes or man- Dry Looks and feels dry Run freely Hard, powdery or friable made fi ll, and should then be termed a buried topsoil. through hands Organic clay, Contains fi nely divided organic matter; may have Moist Feels cool, darkened Tend to cohere Weakened by moisture, silt or sand distinctive smell; may stain; may oxidise rapidly. in colour but no free water on hands Describe as for inorganic soils. when remoulding Peat Consists predominantly of plant remains. Wet Weakened by moisture, free Firm: Fibres already compressed together Spongy: water forms on hands when Very compressible and open stucture Plastic: Can be handling moulded in hand and smears in fi ngers

Saturated Feels cool, darkened in colour and free water is present on the sample MUSCHAMP KARRYN Fibrous: Plant remains recognisable and retain some strength Amorphous: No recognisable plant remains

GRADING (GRAVELS & SANDS) design Roolets Fine, partly decomposed roots, normally found in the upper part of a soil profi le or in a redeposited soil Term Description (e.g. colluvium or fi ll) Well graded Good representation of all particle sizes from largest to smallest

Carbonaceous Discrete particles of hardened (carbonised) plant material. Poorly graded Limited representation of grain sizes - further divided into: WILLIAMS KATE PLASTICITY (CLAYS & SILTS) Uniformly graded Most particles about the same size Term Description Gap graded Absence of one or more intermediate sizes compiled by High Can be moulded or deformed over a wide range of plasticity moisture contents without cracking or showing any NZ GEOTECHNICAL SOCIETY INC tendency to volume change This fi eld sheet has been taken from and should be used and read with reference to the document FIELD DESCRIPTION OF SOIL AND ROCK. Guideline For the Low plasticity When moulded can be crumbled in the fi ngers; may Field Classifi cation and Description of Soil and Rock for Engineering Purposes. show quick or dilatant behaviour NZ Geotechnical Society Inc, December 2005. www.nzgeotechsoc.org.nz Job No: 80508773 BOREHOLE LOG Hole No: BH01 Sheet: 1 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Hunter Terrace Fax: 03 366 7780 Description: Crest of true right bank downstream of Colombo St Bridge Checked: MS Easting: 1570694m Northing: 5176793m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation Progressed by hydro-excavation, so no core retrieved. Observation of excavation walls indicated material is largely uncontrolled fill with distinct layers of construction waste (including glass and bricks). [FILL]

1.0 15.0

(1.2) Gravelly medium to coarse SAND with minor silt and traces of glass; black, 'densely packed', moist, well graded; Gravel, fine to medium, rounded to angular [FILL] AD 21/11 moist

(1.8) Sandy SILT with minor clay and trace gravel; orange mottled black, soft to firm, moist; low plasticity. Sand, fine to medium. Gravel, fine to

medium moist 2.0 [FILL] 14.0 1//1/0/0/0 1 (2) FIBROUS PEAT with some silt and clay; dark brown, very soft, SPT sample moist; low plasticity [FILL] moist

(2.6) Sandy medium to coarse GRAVEL with silt and trace roots; dark brown, 'loosely packed', wet, gap graded; Gravel, sub rounded. Sand, fine to medium [Q1A - 'RIVER ALLUVIUM']

3.0 wet

13.0 11//7/6/7/7 27

SPT sample (3.3) Gravelly fine to medium SAND with trace of cobbles; grey, medium dense, moist, well graded; Gravel. Cobbles, fine to coarse, subrounded to subangular [Q1A - 'RIVER ALLUVIUM'] moist

(4) Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Job No: 80508773 BOREHOLE LOG Hole No: BH01 Sheet: 2 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Hunter Terrace Fax: 03 366 7780 Description: Crest of true right bank downstream of Colombo St Bridge Checked: MS Easting: 1570694m Northing: 5176793m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation

2//1/1/0/0 2 Clayey SILT with minor wood; grey, soft, wet; high plasticity. Wood SPT split spoon sample fragments from 4.35 to 4.45 m. lost due to single coarse [Q1A - 'RIVER ALLUVIUM'] gravel particle at top of SPT sample; however, sample sample recovered from wet core barrel of next drill run. (4.45) Clayey SILT with trace of organics and wood; firm, moist; high plasticity [Q1A - 'RIVER ALLUVIUM']

5.0 11.0

Pushtube sample moist 2//1/1/1/2 5

SPT sample

6.0 10.0

(6.4) Organic clayey SILT with minor roots and wood; dark brown striped grey, firm, moist; high plasticity [Q1A - 'RIVER ALLUVIUM'] moist

(7) 7.0 9.0 1//0/0/0/1 1 Fine SAND with minor silt and trace of roots; very loose, saturated, uniformly graded [Q1A - 'RIVER ALLUVIUM'] SPT sample wet

(8) Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Job No: 80508773 BOREHOLE LOG Hole No: BH01 Sheet: 3 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Hunter Terrace Fax: 03 366 7780 Description: Crest of true right bank downstream of Colombo St Bridge Checked: MS Easting: 1570694m Northing: 5176793m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation

1//1/0/1/1 3 @ 8m becomes sandy SILT with some clay and trace roots. Soft to firm. Medium plasticity. [Q1A - 'RIVER ALLUVIUM'] SPT sample saturated

9.0 7.0 1//1/0/1/2 4

SPT sample

(9.5) @9.5m becomes silty fine SAND with minor clay.

10.0 6.0 1//0/1/0/1 2 saturated SPT sample

(10.45) Borehole terminated at 10.45m due to reaching target depth

11.0 5.0

Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Job No: 80508773 BOREHOLE LOG Hole No: BH02 Sheet: 1 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Waimea Terrace Fax: 03 366 7780 Description: Crest of true left bank downstream of the Colombo St Bridge Checked: MS Easting: 1570687m Northing: 5176814m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation Progressed by hydro-excavation, so no core retrieved. Observation of excavation walls indicated material is largely uncontrolled fill. [FILL]

1.0 15.0

(1.2) SILT with minor sand and trace of roots; greyish brown speckled dark brown, firm, moist; low plasticity. Sand, fine [FILL] AD 21/11 (1.45) moist SILT with some clay , minor sand and trace roots; dark brown, stiff to very stiff, moist; low plasticity. Sand, fine

[BURIED TOPSOIL?] moist (1.65) @1.65 becomes greyish brown with orange speckles [Q1A - 'RIVER ALLUVIUM']

2.0 14.0

4//6/7/9/10 32 moist

SPT sample (2.3) Sandy fine to coarse GRAVEL with some silt and minor cobbles; greyish brown, medium dense, moist, well graded; Gravel, sub rounded. Sand, fine to coarse. Cobbles, subrounded [Q1A - 'RIVER ALLUVIUM'] moist (2.7) Sandy fine to coarse GRAVEL with minor cobbles; greyish brown, 'loosely packed', moist, well graded; Gravel, sub rounded. Sand, fine to coarse

[Q1A - 'RIVER ALLUVIUM'] moist 3.0 (3) 13.0 12//7/7/6/7 27 Sandy fine to coarse GRAVEL with minor cobbles; dark bluish grey, medium dense, moist, gap graded; Sand, medium SPT [Q1A - 'RIVER ALLUVIUM'] sample moist

Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Job No: 80508773 BOREHOLE LOG Hole No: BH02 Sheet: 2 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Waimea Terrace Fax: 03 366 7780 Description: Crest of true left bank downstream of the Colombo St Bridge Checked: MS Easting: 1570687m Northing: 5176814m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation 13//4/1/1/0 6 (4.1) Most of SPT core lost due to gravel particle in SILT with roots/wood, some fine sand and minor clay; dark grey, soft end of split spoon SPT to firm, wet; high plasticity sampler. sample [Q1A - 'RIVER ALLUVIUM'] wet

(5) 5.0

11.0 1//1/1/1/1 4 SILT with some sand and minor clay; light bluish grey, soft, saturated; low to medium plasticity [Q1A - 'RIVER ALLUVIUM'] SPT sample saturated

6.0

10.0 1//0/0/0/1 1

SPT sample

(6.45) SILT with some roots, minor clay and sand.; dark brown, very soft, wet; medium plasticity. Sand, fine. [Q1A - 'RIVER ALLUVIUM'] wet

(7) 7.0 9.0 0//0/0/0/1 1 SILT with minor clay; dark grey, soft, saturated; medium plasticity [Q1A - 'RIVER ALLUVIUM']

SPT sample saturated

Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Job No: 80508773 BOREHOLE LOG Hole No: BH02 Sheet: 3 of 3 Client: Christchurch City Council Started: 10/11/16 MWH NEW ZEALAND LTD Hazeldean Business Park Project: Colombo Beckenham St Wastewater Upgrade Finished: 10/11/16 6 Hazeldean Road Location: Banks of the Heathcote River at its intersection with Colombo St Christchurch 8024 Logged: DG Tel: 03 366 7449 Investigation Location: Waimea Terrace Fax: 03 366 7780 Description: Crest of true left bank downstream of the Colombo St Bridge Checked: MS Easting: 1570687m Northing: 5176814m Inclination: Vertical RL Surface: 16.0m Diameter (Int/Ext): 85mm/122mm Datum: CDD

Shear Standard Material Description Samples Vane Penetration (kPa) Tests (Logging carried out in accordance with Guidelines for the Field Classification of Soil and Rock for Engineering Purposes. New Zealand Geotechnical

Blows Society, 2005) (Seating // (Seating 75mm/150mm, 225mm/300mm) Depth (m) Elevation (m) Type Strength/ Peak Strength Residual N Value/ Refusal Data Graphic Log Moisture Condition Groundwater Observations Other Installation

0//0/1/0/1 2 SILT with minor clay; dark grey, soft, saturated; medium plasticity [Q1A - 'RIVER ALLUVIUM'][continued]

SPT sample saturated (8.5) Silty fine SAND with trace of clay; dark greyish brown, 'loosely packed', saturated, uniformly graded [Q1A - 'RIVER ALLUVIUM'] (8.6) Sandy SILT with trace of organics; dark grey, soft to firm, saturated; low plasticity. Sand, fine [Q1A - 'RIVER ALLUVIUM'] saturated 9.0 (9) 7.0 1//1/1/2/2 6 @9.0m becomes silty fine SAND. Loose.

SPT sample saturated

(9.9) 9.9 - 10.0m lense of uniformly graded fine SAND. 10.0 (10) 6.0 1//0/1/2/3 6 Silty fine SAND and trace of organics; dark grey, loose, saturated, uniformly graded SPT sample

(10.45) saturated Borehole terminated at 10.45m due to reaching target depth

11.0 5.0

Drilling Method: Casing: Remarks: Sonic Rig 125 mm Steel

Contractor: Flush: ProDrill Water Equipment Type: Borehole Completion: FRASTE XL2 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham St WastewaterBanks of Upgrade, 21/11/16 MWH NEW ZEALAND LTD. Project: 80508773, Colombo Beckenham the Heathcote River at its intersection with Colombo St www.mwhglobal.com/nz Photographic Log

Client: Christchurch City Council Project: Colombo Beckenham St Wastewater Upgrade Site Name: Colombo St Syphon Site Location: Heathcote River immediately downstream of the Colombo St Bridge Photograph ID: 1 Borehole No: BH01 Depth Range: 1.2 to 5.45 m below ground level Date of Drilling: 10/11/2016 Comments: Borehole progressed by hydro-excavation between 0 and 1.2 m below ground level as a safety precaution against unidentified services.

Photograph ID: 2 Borehole No: BH01 Depth Range: 5.45 to 9.0 m below ground level Date of Drilling: 10/11/2016 Comments:

Page 1 of 3 Photographic Log

Client: Christchurch City Council Project: Colombo Beckenham St Wastewater Upgrade Site Name: Colombo St Syphon Site Location: Heathcote River immediately downstream of the Colombo St Bridge Photograph ID: 3 Borehole No: BH01 Depth Range: 9.0 to 10.45 m below ground level Date of Drilling: 10/11/2016 Comments:

Photograph ID: 4 Borehole No: BH02 Depth Range: 1.2 to 4.45 m below ground level Date of Drilling: 10/11/2016 Comments: Borehole progressed by hydro-excavation between 0 and 1.2 m below ground level as a safety precaution against unidentified services.

Page 2 of 3 Photographic Log

Client: Christchurch City Council Project: Colombo Beckenham St Wastewater Upgrade Site Name: Colombo St Syphon Site Location: Heathcote River immediately downstream of the Colombo St Bridge Photograph ID: 5 Borehole No: BH02 Depth Range: 4.45 to 8.45 m below ground level Date of Drilling: 10/11/2016 Comments:

Photograph ID: 6 Borehole No: BH02 Depth Range: 8.45 to 10.45 m below ground level Date of Drilling: 10/11/2016 Comments:

Page 3 of 3

Christchurch

Hazeldean Business Park, 6 Hazeldean Road Addington, Christchurch 8024 PO Box 13-052, Armagh Christchurch 8141 Tel +64 3 366 7449 Fax +64 3 366 7780

www.mwhglobal.com

Colombo-Beckenham Wastewater Upgrade

Appendix B Permitted Activities Assessment

Overview - Permitted Activities (Canterbury Land and Water Regional Plan) Permit Rule Activity and Activity Status Comment type

As per the Regional Plan, the definition of stormwater includes The discharge of stormwater into a river, lake, sediment generated during wetland or artificial watercourse or onto or into construction or earthworks. land in circumstances where a contaminant Erosion and sediment control may enter a river, lake, wetland, or artificial measures in accordance with Environment Canterbury’s Discharge watercourse will be assessed as a permitted 5.95 Erosion and Sediment Control Permit activity when the discharge is into a reticulated stormwater system and the Guideline 2007 will be discharger has obtained written permission implemented along the length of from the system owner to discharge into the the Project during all land system. disturbance works to prevent the discharge of sediment laden water to the stormwater system, for which permission is being sought. Subject to meeting the conditions below, the The CCC hold permits to take taking of water from groundwater for the and discharge groundwater for purpose of de-watering for carrying out site dewatering purposes excavation, construction, maintenance and (Consent No. CRC121311 and geotechnical testing and the associated use CRC121310). These permits and discharge of that water is a permitted also apply to the work proposed activity: under this Project. Groundwater that is encountered from dewatering 1. The take continues only for the time activities will be discharged in required to carry out the work but the accordance with the conditions take shall not last for a period exceeding of these consents, and diverted 6 months; and into Christchurch City Council’s 2. The abstraction is not from a site where reticulated stormwater system. an activity or industry listed in Schedule 3 has occurred or is occurring; and 3. The take does not lower the groundwater level more than 8 m below the ground Discharge level of the site or cause subsidence of 5.119 Permit any other site; and 4. The take does not have a moderate, high or direct stream depletion effect on a surface waterbody, determined in accordance with Schedule 9, unless the abstracted groundwater is being discharged to the surface waterbody to which it is hydraulically connected; and 5. An assessment of interference effects, undertaken in accordance with Schedule 12, does not show that any community, group or private drinking-water supply bore will be prevented from taking water; and 6. At the point and time of any discharge to surface water, the rate of flow in the river or artificial watercourse is at least five times the rate of the discharge; and

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Colombo-Beckenham Wastewater Upgrade

7. The concentration of suspended solids in any discharge to a surface waterbody does not exceed 100 g/m³; and 8. The discharge is not within a Group or Community Drinking-water Protection Zone as set out in Schedule 1. Subject to meeting the conditions below, the drilling, tunnelling, or disturbance in or under the bed of a lake or river and the installation, 1. The activity will not occur maintenance, or removal of pipes, ducts, in the bed of a lake or cables or wires is a permitted activity: salmon spawning site; 1. The activity is not undertaken in, on, or 2. The activity will be located under the bed of a lake listed as a high beneath the bed of the naturalness lake in Sections 6 to 15 or in river and as such, there an inanga or salmon spawning site listed will be no deposition of any in Schedule 17; and substances; 2. The activity does not involve the 3. The Christchurch City deposition of any substance, other than Council is the owner of the bed material, on the bed of a lake or Colombo Street bridge, river; and which is within 10m of the 3. The activity is undertaken at a distance proposed works; 5.136 Land use greater than 10m from any dam, weir, 4. The bed of the river will not

bridge, or network utility pole, pylon or require recontouring, as flood protection vegetation, or 150m from the pipe will be installed any water level recorder, or 50m from beneath the bed of the any defence against water, or closer river; where there is evidence that permission 5. Marker posts will be has been obtained from the owner of the erected for the life of the infrastructure or the works are being pipe on the banks of the carried out by or on behalf of the owner; Heathcote River; and 6. As described in the 4. Within 30 days of the completion of the Report, works will not be activity the bed of the lake or river is undertaken in flowing returned to its original contour; and water. 5. Marker posts are erected for the lifetime

of the pipes, ducts, cables or wires; and 6. The works do not occur in flowing water. Subject to meeting the following conditions, 1. Erosion and sediment temporary discharges to water or to land in control measures in circumstances where a contaminant may accordance with enter water associated with undertaking Environment Canterbury’s activities in Rules 5.135 to 5.140 or in relation Erosion and Sediment to artificial watercourses are permitted Control Guideline 2007 will activities: be implemented along the 1. The discharge is only of sediment, length of the Project during organic material and water originating all land disturbance works from within the bed of the lake or river; to prevent the discharge of and sediment laden water to Discharge 5.141 nearby waterbodies and permit 2. The discharge is not undertaken in an stormwater system; inanga or salmon spawning site listed in Schedule 17; and 2. The proposed works will not occur any areas 3. The discharge is not for more than ten identified in Schedule 17; hours in any 24-hour period, and not more than 40 hours in total in any 3. Any potential temporary calendar month. discharges where a contaminant may enter water will be managed so as to meet this condition, in order to manage any potential adverse effects;

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Colombo-Beckenham Wastewater Upgrade

Subject to conditions, the use of land for 3. The proposed works will earthworks outside the bed of a river or lake not occur any areas or adjacent to a wetland boundary but within identified in Schedule 17; 5m of the bed of a lake or river is permitted. 4. Earthworks will not occur As the proposed works are for the within 5m of any known establishment of network utilities, conditions 3 flood control structure; and 4 of Rule 5.168 apply: 3. The activity does not occur adjacent to a Land use significant spawning reach for salmon or 5.168(b)(1) an inanga spawning area listed in Schedule 17; and 4. Except in relation to recovery activities or the establishment, maintenance or repair of network utilities and fencing, any earthworks or cultivation is not within 5m of any flood control structure

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