Report with Form 9 28.04

CONTACT ENERGY LIMITED

GEOFUTURE

Expansion of Te Mihi Power Station

Land Use Consent Application to Taupo District Council

6 August 2021


TABLE OF CONTENTS

Part A: Resource Consent Application

Part B: Assessment of Environmental Effects

Executive Summary

1. Introduction __________________________________________________________ 5

1.1 Contact Energy Limited 5 1.2 Te Mihi Power Station 5 1.3 Proposed Expansion of the Te Mihi Power Station 7 1.4 Geofuture - The Wider Context 9 1.5 AEE Report Structure 10 1.6 Technical Studies Undertaken 11

2. Description of the Existing Environment ____________________________________ 12

2.1 Geology, Topography and Land Uses 12 2.2 Wairakei Geothermal Power Scheme 14 2.3 Terrestrial Ecology and Waterbodies 14 2.4 Cultural History and Setting 15 2.5 Other Environmental Characteristics 17 2.6 The Existing Environment – Legal Context 17

3. Proposed Activities ____________________________________________________ 19

3.1 Location of Future Power Plants 19 3.2 Te Mihi Electricity Generation Plant Options 22 3.3 Key Features of the Proposed Expansion of Te Mihi Power Station 25 3.4 Switchyards and Electricity Transmission 25 3.5 Site Access 25 3.6 Construction Activities 26 3.7 Plant Operations and Maintenance Activities 27 3.8 Future of the Wairākei A & B Power Stations 27

4. RMA Status of Activities ________________________________________________ 28

4.1 Taupō District Council Jurisdiction 28 4.2 Waikato Regional Council Jurisdiction 33 4.3 Joint Applications 33

5. Assessment of Applications _____________________________________________ 35

5.1 Section 104 of the RMA 35 5.2 Section 104B of the RMA 35

6. Positive Effects _______________________________________________________ 37

6.1 Economic Benefits 37 6.2 Decarbonising the Economy 39

7. Landscape and Visual Effects ___________________________________________ 40

8. Noise Effects ________________________________________________________ 42


9. Transportation Effects _________________________________________________ 46

10. Archaeological Effects _________________________________________________ 48

11. Cultural Values _______________________________________________________ 49

12. Management of Hazardous Substances ____________________________________ 51

12.1 Current Use of Hazardous Substances 51 12.2 Hazardous Substances Review 51 12.3 Hazardous Substances to be stored and used 52 12.4 Major Hazard Facilities and Hazardous Substances Compliance 52 12.5 Major Incident Analysis 53

13. Contaminated Soils, Fault LInes and Hot ground ____________________________ 57

13.1 Contaminated Soils 57 13.2 Fault Lines and Hot Ground Hazard 57

14. Air Quality Effects ____________________________________________________ 58

15. Effects on Terrestrial Ecology and Thermotolerant Vegetation __________________ 59

16. Policy and Planning Assessment _________________________________________ 60

16.1 Vision and Strategy for the Waikato River 60 16.2 National Policy Statement for Renewable Electricity Generation 61 16.3 National Policy Statement on Electricity Transmission 61 16.4 National Environmental Standard for Contaminants in Soil 62 16.5 Waikato Regional Policy Statement 62 16.6 Waikato Regional Plan 63 16.7 Taupō District Plan 63 16.8 Ngāti Tūwharetoa Iwi Environmental Management Plan 64 16.9 Part 2 of the RMA 65

17. Consultation and Engagement __________________________________________ 69

17.1 Taupō District Council 69 17.2 Waikato Regional Council 69 17.3 Tangata Whenua 70 17.4 Transpower NZ Limited 71 17.5 Department of Conservation 71 17.6 Waka Kotahi / New Zealand Transport Agency 72 17.7 Neighbours and General Public 72

18. Proposed Consent Conditions ___________________________________________ 73

19. Lapse Period and Term of Consent _______________________________________ 74

19.1 Lapse Period 74 19.2 Term of Consent 74

20. Notification of the Application ___________________________________________ 75

21. Conclusion __________________________________________________________ 76


LIST OF APPENDICES

Appendix 1: Records of Title and Survey Office Plan

Appendix 2: Plans of Proposed Power Station Options

Appendix 3: Taupo District Plan - Analysis of Rules and Performance Standards

Appendix 4: Hot Ground Assessment

Appendix 5: Economic Benefit Assessment

Appendix 6: Landscape and Visual Assessment

Appendix 7: Acoustical Assessment

Appendix 8: Independent Peer Review of Acoustical Assessment

Appendix 9: Integrated Transportation Assessment

Appendix 10: Archaeological Assessment

Appendix 11: Te Mihi Binary Plant Major Incident Analysis

Appendix 12: Preliminary Site Investigation

Appendix 13: Analysis of Policy and Planning Documents

Appendix 14: Draft Land Use Consent and Proposed Conditions


REPORT INFORMATION

Report Status FINAL

Our Reference MDL001036

File Location Contact – GeoFuture – Application and AEE – Taupo District Council – Final – 060821

Author Mark Chrisp

Review By GeoFuture Project Team

Version Number 1

Version Date 6 August 2021

© Mitchell Daysh Limited (2021).

This document and its contents are the property of Mitchell Daysh Limited. Any unauthorised employment or reproduction, in full or in part, is forbidden.

LIST OF ABBREVIATIONS AND ACRONYMS

ACC Air Cooled Condensers

BOI Board of Inquiry

CIA Cultural Impact Assessment

Contact Contact Energy Limited

DOC Department of Conservation

ESCP Erosion and Sediment Control Plan

FP Flash Plant

GGC Geothermal Group Control

HAIL Hazardous Activities and Industries List


ITA Integrated Transportation Assessment

LP Low Pressure

MDCT Mechanical Draft Cooling Tower

NES-ETA Resource Management (National Environmental Standards for Electricity Transmission Activities) Regulations 2009

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

NPS-ET National Policy Statement on Electricity Transmission 2008

NPS-REG National Policy Statement for Renewable Electricity Generation 2011

NZECP New Zealand Code of Practice for Electrical Safe Distances (NZECP 34:2001)

PSI Preliminary Site Investigation

RMA Resource Management Act 1991

RPS Waikato Regional Policy Statement

SGF Significant Geothermal Feature

SGW Separated Geothermal Water

SNA Significant Natural Area

STG Steam Turbine Generator

TDC Taupō District Council

TDP Taupō District Plan

WBF Western Bore Field

WRC Waikato Regional Council

WRP Waikato Regional Plan

A PART A

Resource Consent Application

Expansion of Te Mihi Power Station 1

FORM 9

APPLICATION FOR RESOURCE CONSENT

Under section 88 of the Resource Management Act 1991

To: Taupō District Council 30 Tongariro Street TAUPŌ 3330

1. CONTACT ENERGY LTD, whose address is Level 2, Harbour City Tower, 29 Brandon

Street, PO Box 10742, Wellington 6143 (note address for service below) applies for the following type(s) of resource consent:

Land Use Consent

2. The activity to which the application relates (the proposed activity) is as follows:

To construct, operate, maintain, replace, renew, and undertake minor upgrading of an expansion to the Te Mihi Power Station and all associated structures, equipment, facilities, signage, earthworks, internal site roading, and 220kV grid connection, to the extent that it involves activities beyond that which are authorised by Land Use Consent RM0703041 (more fully described in Part B of this document) including:

o Option 1 (THI_1) – A single large steam turbine located within the existing consented footprint (Site THI A), with a gross output up to 180MW; or

o Option 2 (THI_2) – Two smaller steam turbines, one on the existing consented footprint (Site THI A) and one further southeast (Site THI B), with a combined gross output up to 180MW; or

o Option 3 (THI_3) – Organic Rankine Cycle Binary Plant, consisting of up to four units located on a footprint to the southeast of the existing Te Mihi Power Station (Site THI B), with a gross output up to 165MW.

A Land Use Consent is required due to the proposed activity exceeding several performance standards in the Taupō District Plan.

3. A lapse period of 10 years is sought in relation to the above application.

1 As amended by consent granted by Taupō District Council on 4 August 2010 under s.127 of the RMA

(referred to as Land Use Consent RM070304A).


4. The applicant requests its application be publicly notified.

5. The site on which the proposed activity is to occur is in the vicinity of the existing Te Mihi Power Station within the area shown on the following plans attached as Schedule 1 to this application:

Plan 1: Te Mihi Power Station Expansion – Land Use Consent Area; and

Plan 2: Te Mihi Power Station Expansion Sites THI A and THI B.

Physical Address:

136 Oruanui Road, Taupō.

Legal Description:

Lot 3 DP 454472 (Record of Title 583496);

Section 4 SO 355555; and

Area 1 DP 445146.

The relevant Records of Title and Survey Office Plan are presented in Appendix A.

6. Contact Energy Limited is the owner and occupier of Lot 3 DP 454472 and is the lessee

and occupier of Section 4 SO 355555.

The owner of Section 4 SO 355555 is:

The Crown acting through the Commissioner of Crown Lands C/o Land Information New Zealand PO Box 5501 WELLINGTON

Attention: Naomi Bray and Megan McKinstry

Transpower New Zealand Ltd is the owner and occupier of Area 1 DP 445146 (being the switchyard located immediately north of Te Mihi Power Station).

7. There are no other activities that are part of the proposal to which this application relates.

8. The following additional resource consent is required for the proposed activity to which this application relates:

Air Discharge Permit.

An application will be lodged with Waikato Regional Council for an Air Discharge Permit at a later date (expected to be by the end of 2021) as part of a more comprehensive


application for a suite of regional resource consents intended to replace existing consents governing the applicant’s take and discharge of geothermal water, and associated activities, that expire on 30 June 2026.

9. I attach (as part of Part B of this document) an assessment of the proposed activity’s effect on the environment that—

(a) includes the information required by clause 6 of Schedule 4 of the Resource Management Act 1991;

(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.

10. I attach (as part of Part B of this document) an assessment of the proposed activity against

the matters set out in Part 2 of the Resource Management Act 1991.

11. I attach (as part of Part B of this document) an assessment of the proposed activity against

any 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.

12. Beyond the matters listed above, no further information is required to be included in this

application by the district plan, the regional plan, the Resource Management Act 1991, or any regulations made under that Act.

Dated this 6th day of August 2021.

Signature: Contact Energy Limited

_______________________________

Chris Drayton


Address for Service: Buddle Findlay Aon Centre 1 Willis Street PO Box 2694 WELLINGTON 6140

Contact person: David Allen

Telephone: 04 499 4242

DDI: 04 462 0423

Mobile: 021 955 744

Email: [email protected]

Address for Billing: Contact Energy Limited Level 2 Harbour City Tower 29 Brandon Street PO Box 10742 WELLINGTON 6143

Attention: Bernd Pummer

Phone: 021 779 449

Email: [email protected]

mailto:[email protected]

mailto:[email protected]


SCHEDULE 1

Plan 1: Te Mihi Power Station Expansion – Land Use Consent Area

Plan 2: Te Mihi Power Station Expansion Sites THI A and THI B

B PART B

Assessment of Environmental Effects


Executive Summary

Contact Energy Limited (“Contact”) owns and operates Te Mihi Power Station located at 136 Oruanui Road, approximately 6km north of Taupō. It was established and operates in accordance with a suite of resource consents granted by a Board of Inquiry in September 2008, including a Land Use Consent within the jurisdiction of Taupō District Council (“TDC”) (Consent RM070304).

Stage 1 of Te Mihi Power Station, which involved the installation of two condensing steam turbine units, was commissioned in 2014. Contact has the ability to construct and commission a third condensing stream turbine unit under Consent RM070304. The site for the third turbine unit and associated cooling tower (referred to as Site THI A) was prepared as part of the construction of Stage 1 of the Te Mihi Power Station.

However, a new application for a Land Use Consent is being sought under s.88 of the Resource Management Act 1991 (“RMA”) for the expansion of Te Mihi Power Station (as set out in Part A of this document). This is because aspects of the proposed options for Stage 2 of Te Mihi Power Station are beyond the scope of what is authorised under Consent RM070304 in terms of location and/or the size and nature of the electricity generation plant.

Plan 1 shows the proposed Land Use Consent Area for the expansion of Te Mihi Power Station.

Plan 1: Te Mihi Power Station Expansion – Land Use Consent Area

There are two proposed locations for the expansion of the Te Mihi Power Station within the Land Use Consent Area – referred to as Site THI A (being the site of the consented


third steam turbine unit adjacent to Stage 1 of Te Mihi Power Station) and Site THI B (being a much larger site to the east of the existing Te Mihi Power Station) as shown on Plan 1.

The options for Stage 2 of the Te Mihi Power Station are:

Option 1 (THI_1) – A single large steam turbine located within the existing consented footprint (Site THI A), with a gross output up to 180MW; or

Option 2 (THI_2) – Two smaller steam turbines, one on the existing consented footprint (Site THI A) and one further southeast (Site THI B), with a combined gross output up to 180MW; or

Option 3 (THI_3) – Organic Rankine Cycle Binary Plant, consisting of up to four units located on a new footprint to the southeast of the existing Te Mihi Power Station (Site THI B), with a gross output up to 165MW.

A Land Use Consent is required (as a Discretionary Activity) due to the proposed expansion of Te Mihi Power Station exceeding several performance standards in the Taupō District Plan.

The proposed expansion of the Te Mihi Power Station is part of a larger project being advanced by Contact referred to as “GeoFuture”. GeoFuture is about reconfiguring and reconsenting Contact’s activities on the Wairākei Field (forming part of the wider Wairākei-Tauhara Geothermal System) in order the achieve a more efficient utilisation of the geothermal resource for renewable electricity generation purposes and to reduce any adverse effects on the Waikato River. Resource consent applications will be lodged with Waikato Regional Council at a later date (anticipated to be at the end of 2021) for all activities on the Wairākei Field which require a resource consent under the Waikato Regional Plan.

An Assessment of Environmental Effects has been undertaken in relation to the Land Use Consent Application for the proposed expansion of Te Mihi Power Station. That assessment concludes that the proposal, as a key part of GeoFuture, will result in:

A net increase in renewable electricity generation equivalent to the demand of up to 70,000 households with only a modest (around 2%) increase in geothermal fluid take;

Significant economic benefits on the local and regional economy including $520 million to $600 million in revenue terms during the construction phase;

A reduction in New Zealand’s greenhouse gas emissions associated with a greater proportion of electricity being generated from a renewable source;

The cessation of separated geothermal water discharges to the Waikato River associated with Contact’s electricity generation activities;

The closure of the Wairākei A & B Power Stations resulting in the discontinuance of geothermal condensate being discharged to the Waikato River;


No, or less than minor, landscape and visual effects (depending on which option is constructed);

Compliance with the relevant noise limits specified in the Taupō District Plan;

Construction traffic being managed to ensure the safety and efficiency of the roading network is maintained;

No adverse effects on any recorded or known archaeological sites alongside a set of cultural / archaeological protocols in relation to any accidental discovery;

No adverse effects on identified culturally significant sites (none being located within the Land Use Consent Area);

The storage and use of hazardous substances in accordance with relevant legislation, regulations and environmental best practice to minimise any risk to human health and the environment;

No adverse effects in relation to contaminated soils (none being present or otherwise being appropriately managed if discovered during construction);

Fault lines avoided and any hot ground encountered being properly managed in relation to the construction of any of the proposed power station options on Site THI B;

Construction activities, including earthworks, being managed to avoid any dust or silt nuisance beyond the site; and

No adverse effects on terrestrial ecology, streams or thermotolerant vegetation.

On the basis of the above outcomes, the proposed expansion of Te Mihi Power Station is consistent with the relevant objectives and policies in the applicable policy and planning documents, including:

Vision and Strategy for the Waikato River;

National Policy Statement for Renewable Electricity Generation 2011;

National Policy Statement on Electricity Transmission 2008;

National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health 2011;

Waikato Regional Policy Statement;

Waikato Regional Plan;

Taupō District Plan; and

Ngāti Tūwharetoa Iwi Environmental Management Plan.

The proposal is also consistent with Part 2 (Purpose and Principles) of the RMA.


Contact has proffered a proposed set of consent conditions which are intended to address and control the nature and magnitude of any actual or potential adverse effects on the environment associated with the proposed expansion of the Te Mihi Power Station. The proposed conditions are based on, and most of them are the same or similar (at least in substance) to, the existing conditions in Consent RM070304 as applicable. Additional conditions have also been proffered that specifically relate to aspects of the proposed expansion of Te Mihi Power Station which are beyond the activities authorised under Consent RM070304.

Despite the absence, or minor nature, of any adverse effects on the environment, Contact has requested that TDC publicly notify the Land Use Consent Application for the proposed expansion of Te Mihi Power Station to provide a formal opportunity for interested and potentially affected parties to lodge submissions and have the ability to be heard at a hearing (if they wish to do so).


1. INTRODUCTION

1.1 CONTACT ENERGY LIMITED

Contact Energy Limited (“Contact”) is the second largest electricity generator / retailer in New Zealand with a flexible and largely renewable portfolio of electricity generation assets. Contact owns and operates 11 power stations across the country and currently produces 80-85% of its electricity from renewable hydro and geothermal resources. Contact is New Zealand’s largest producer of renewable electricity from geothermal resources with the operation of its Wairākei A & B Power Station, Wairākei Binary Plant, Poihipi Road, Te Mihi, Ohaaki and Te Huka Power Stations.

1.2 TE MIHI POWER STATION

Te Mihi Power Station is located at 136 Oruanui Road, approximately 6km north of Taupō and 5km west of the Wairākei Power Station as shown in Figure 1.1.

Figure 1.1 - Location of the Te Mihi Power Station


A suite of resource consents was granted by a Board of Inquiry (“BOI”) in September 2008 authorising the construction and operation of the Te Mihi Power Station. The Land Use Consent for the Te Mihi Power Station (Consent RM070304) granted by the BOI, within the jurisdiction of Taupō District Council (“TDC”), included:

Authorisation for the installation and operation of three 78MW condensing stream turbine units (nominally totalling 220 MW (net) of electricity generation capacity);

The ability to develop the power station in stages (as was proposed as part of the application); and

A defined ‘Proposed Te Mihi Power Station Site’ (being an area within which the power station could be located) shown in green hatching on Figure 1.2.

Figure 1.2 - Te Mihi Power Station Site

Consent RM070304 was amended by a consent granted by Taupō District Council on 4 August 2010 under s.127 of the Resource Management Act 1991 (“RMA”) (referred to as Land Use Consent RM070304A). The amendment to the consent allowed an alternative layout and orientation of the Te Mihi Power Station which remained within the Proposed Te Mihi Power Station Site shown on Figure 1.2.


Stage 1 of Te Mihi Power Station, which involved the installation of two condensing steam turbine units, was commissioned in 2014. The construction of Stage 1 of Te Mihi Power Station created significant economic benefits for the Taupō District and the wider Waikato Region. By increasing the amount of electricity generated from a renewable source, it also assisted with the progressive decarbonisation of the New Zealand economy.

1.3 PROPOSED EXPANSION OF THE TE MIHI POWER STATION

Contact has the ability to construct and commission the proposed third condensing steam turbine unit under Consent RM070304. The site for the third steam turbine unit and associated cooling tower (referred to as Site THI A) was prepared as part of the construction of Stage 1 of the Te Mihi Power Station (see Figure 1.3).

Figure 1.3 – Photo of Site THI A prepared for a third steam turbine unit adjacent to Stage 1 of the Te Mihi Power Station

However, a new application for a Land Use Consent is being sought (under s.88 of the RMA) for the expansion of the Te Mihi Power Station (as set out in Part A of this document). This is because aspects of the proposed options for Stage 2 of the Te Mihi Power Station are beyond the scope of what is authorised under Consent RM070304 in terms of location and/or the size and nature of the electricity generation plant.

Figure 1.4 is the proposed Land Use Consent Area for the expansion of Te Mihi Power Station. There are two proposed locations for the expansion of the Te Mihi Power Station within the Land Use Consent Area – referred to as Site THI A (being the site of the consented third steam turbine unit adjacent to Stage 1 of the Te Mihi Power Station – shown in Figure 1.3) and Site THI B (being a much larger site to the east of the existing Te Mihi Power Station) as shown in Figure 1.4.


Figure 1.4 - Te Mihi Power Station Expansion – Land Use Consent Area

Site THI B is a gently rolling area of land currently in pasture and forestry as shown in Figure 1.5.

Figure 1.5 – Photo of Site THI B (looking towards the east from Site THI A)

The options for Stage 2 of the Te Mihi Power Station are:

Option 1 (THI_1) – A single large steam turbine located within the existing consented footprint (Site THI A), with a gross output up to 180MW; or


Option 2 (THI_2) – Two smaller steam turbines, one on the existing consented footprint (Site THI A) and one further southeast (Site THI B), with a combined gross output up to 180MW; or

Option 3 (THI_3) – Binary Plant (also referred to as an Organic Rankine Cycle Plant), consisting of up to four units located on a new footprint to the southeast of the existing Te Mihi Power Station (Site THI B), with a gross output up to 165MW.

A more detailed description of the options proposed is presented in Section 3.

1.4 GEOFUTURE - THE WIDER CONTEXT

The proposed expansion of the Te Mihi Power Station is part of a larger project being advanced by Contact referred to as “GeoFuture”. GeoFuture is about reconfiguring and reconsenting Contact’s activities on the Wairākei Field (forming part of the wider Wairākei-Tauhara Geothermal System) in order to achieve a more efficient utilisation of the geothermal resource for renewable electricity generation purposes and to reduce any adverse effects on the Waikato River. GeoFuture involves the following key elements:

Increasing the generation of renewable and reliable baseload electricity (from about 320 MW to up to 400 MW) using the same or similar amount of geothermal fluid. The increase in electricity generated will be the equivalent of the power consumed by 70,000 households and will help New Zealand reduce its greenhouse gas emissions, including from gas and coal-fired power stations;

Continuing to operate the Wairākei A & B Power Stations until 30 June 2031 at the latest, by which time they will be decommissioned;

Expanding the generation capacity of the Te Mihi Power Station (beyond that which can occur under Consent RM070304 granted by the BOI in 2008). This will result in a significant investment in the local and regional economy. The estimated cost of Stage 2 of the Te Mihi Power Station is up to $800 million, with approximately 33% of that being spent within the Waikato and Bay of Plenty regions;

Possibly constructing a new small (up to 40 MW) geothermal power station on the Wairākei Power Station Site (utilising geothermal fluid from the Western Borefield (“WBF”) which cannot be conveyed uphill to the Te Mihi Power Station);

Cease operational discharges of Separated Geothermal Water (“SGW”) to the Wairākei Stream and the Waikato River by 30 June 2026 at the latest;

Cease the discharge of geothermal condensate to the Waikato River by 30 June 2031 at the latest (as part of shutting down the Wairākei A & B Power Stations); and

Continue to facilitate the operation of various cascade users of geothermal heat and fluid.


1.5 AEE REPORT STRUCTURE

Following this introduction, the structure of this AEE is as follows:

Section 2 Describes the existing environment.

Section 3 Describes the proposed activities which are the subject of the Land Use Consent Application in Part A of this document.

Section 4 Identifies the RMA consenting status of the proposed activities as determined by the operative Taupō District Plan and relevant regulations.

Section 5 Sets out the sections of the RMA that are relevant to the assessment of the Land Use Consent Application.

Section 6 Provides an assessment of the economic benefits associated with the proposed activities.

Section 7 Provides an assessment of the landscape and visual effects associated with the proposed activities.

Section 8 Provides an assessment of the noise effects associated with the proposed activities.

Section 9 Provides an assessment of the transportation effects associated with the proposed activities.

Section 10 Provides an assessment of the archaeological effects associated with the proposed activities.

Section 11 Provides an assessment of the effects of the proposed activities on cultural values.

Section 12 Discusses the management of hazardous substances and the results of a Major Incidents Analysis.

Section 13 Provides an assessment in relation to any contaminated soils, fault lines and hot ground hazard.

Section 14 Provides an assessment of the air quality effects (in terms of amenity) associated with the proposed activities.

Section 15 Provides an assessment of the effects of the proposed activities on terrestrial ecology and thermotolerant vegetation.

Section 16 Presents an assessment of the proposed activities in relation to the provisions in the relevant policy and planning documents prepared under the RMA and in relation to Part 2 of the RMA.


Section 17 Describes the consultation undertaken and the results of that consultation.

Section 18 Discusses the nature of consent conditions that are proffered by Contact.

Section 19 Sets out the proposed lapse period and term of consent sought by Contact.

Section 20 Requests that the application be notified.

Section 21 Presents an overall conclusion.

1.6 TECHNICAL STUDIES UNDERTAKEN

Various technical studies have been undertaken in relation to the proposed expansion of the Te Mihi Power Station. The reports produced as a result of those studies (attached as appendices to this AEE) are as follows:

Hot Ground Assessment

Economic Benefit Assessment

Landscape and Visual Assessment

Acoustical Assessment

Independent Peer Review of Acoustical Assessment

Integrated Transportation Assessment

Archaeological Assessment

Te Mihi Binary Plant Major Incident Analysis

Preliminary Site Investigation


2. DESCRIPTION OF THE EXISTING ENVIRONMENT

2.1 GEOLOGY, TOPOGRAPHY AND LAND USES

The Wairākei-Tauhara Geothermal System is one of fifteen geothermal systems in the Waikato Region which form part of the Taupo Volcanic Zone. It comprises two hydrologically connected reservoirs, referred to as the Wairākei Field and the Tauhara Field that, for the most part, sit north and east of Taupō township respectively. The Wairākei and Tauhara fields cover areas of approximately 30 km2 and 50 km2 respectively. The Te Mihi Power Station site is located on the north-western part of the Wairākei Field (see Figure 2.1).

Figure 2.1 – Wairākei-Tauhara Geothermal System

The underlying site geology is rhyolite associated with pumiceous pyroclastics (NZ Geological Survey, DSIR 1972). The rolling landscape is formed by a series of rhyolite domes. The resultant pumice soils are light, free draining, and prone to drought during the summer. The site is on rolling topography, at the north-western edge of the Wairākei Field,


which is generally bounded by SH 1, Link Road, Oruanui Road and Poihipi Road (see Figure 2.2). The land surrounding the Te Mihi Power Station site is largely managed in pasture with plantation forestry to the east, and further south of the site.

Figures 1.1 and 2.2 show the area in which Te Mihi Power Station is located and the surrounding land uses.

Figure 2.2 – Aerial Photograph of Te Mihi Power Station and the Surrounding Area

Much of the land surrounding Te Mihi Power Station is used for farming, forestry and geothermal steamfield activities. To the north of Te Mihi Power Station, along Oruanui Road and Link Road, the predominant land use is lifestyle blocks.

Poihipi Road Power Station is located approximately 1 km to the south of Te Mihi Power Station. The Taupō Sale Yards and the Oruanui Pony and Taupō Western Riding Clubs are located a short distance to the west of Te Mihi Power Station adjacent to the intersection of Poihipi Road and Oruanui Road. Te Mihi Power Station has its access (a private sealed two-lane road) onto Oruanui Road approximately 400m north of the Taupō Sale Yards.


2.2 WAIRAKEI GEOTHERMAL POWER SCHEME

The existence of Te Mihi Power Station and associated steamfield activities is a key aspect of the existing environment. These activities, which are of a heavy industrial character, form part of the wider Wairakei Geothermal Power Scheme owned and operated by Contact. In addition to Te Mihi Power Station, the Wairakei Geothermal Power Scheme includes:

Wairākei A & B Power Stations;

Wairākei Binary Plant;

Poihipi Road Power Station;

Geothermal production wells, reinjection wells and monitoring wells;

Separation / Flash Plants;

Water intake and outfall structures;

Man-made, lined geothermal fluid holding ponds and associated pump stations and drilling water reservoirs;

Steamfield roads and tracks; and

A comprehensive network of geothermal pipelines and medium voltage electricity distribution lines.

The location of the various power stations and geothermal wells are shown on Figure 2.1.

Transpower NZ Ltd owns and operates switchyards and high voltage transmission lines, including one immediately north of Te Mihi Power Station and the transmission line between the Te Mihi switchyard and the Poihipi Road Power Station.

2.3 TERRESTRIAL ECOLOGY AND WATERBODIES

The terrestrial ecology of the area in which the Te Mihi Power Station is located is highly modified. The actual power station site, including Site THI A, is predominantly covered in hard stand (concrete and tar seal) or gravel (see the photo in Figure 1.3). Approximately two-thirds of Site THI B is gently rolling pastoral farmland while the balance is planted in production forestry (pinus radiata) (see Figures 1.4 and 1.5).

The wider area surrounding Te Mihi Power Station comprises farmland including some shelter belts of exotic tree species and the occasional self-sown native tree. The Wairākei Field is generally covered with grass and scrubby vegetation. Sites THI A and THI B, on which the expansion of Te Mihi Power Station is proposed, do not contain any significant indigenous vegetation or significant habitats of indigenous fauna.

Beyond Site THI B to the east is the Alum Lakes area which is identified on the Taupō District Plan as a Significant Natural Area (“SNA”) (discussed in Section 4). The same area


is identified in the Waikato Regional Plan as a Significant Geothermal Feature (“SGF”). This area will not be impacted by the proposed activities.

There is only one stream in the vicinity of the Te Mihi Power Station. Te Kiri o Hinekai Stream2 originates just south of the Te Mihi Power Station. It is identified in the Waikato Regional Plan as a SGF, however there is no geothermal water in the upper reaches of the Te Kiri o Hinekai Stream in the vicinity of Te Mihi Power Station (and nor has there been historically).3 The stream is a mostly dry ephemeral stream bed which, remains in its natural state for about 600m heading east and picking up surface stormwater runoff along the way. It then passes through a culvert under a road at the western end of the WBF. The stream is then channelled within a U-shaped concrete canal and diverted into the Main Drain on Contact’s land. The Main Drain is a parallel set of two U-shaped concrete canals including several weir / gate structures and culverts under roads and tracks.

Te Kiri o Hinekai Stream only has geothermal water flowing in its lower reaches as a result of Contact discharging SGW to the stream bed near FP14 a short distance upstream of Netcor / Wairākei Terraces and discharges to the stream from the geyser, pink and white terraces, and geothermal hot pools forming part of Wairākei Terraces. The discharge of SGW by Contact to Te Kiri o Hinekai Stream is to maintain a flow of geothermal water in the stream in accordance with the wishes of local hapū. At the end of the Main Drain, is the Western Borefield Holding Pond (colloquially known as Lake Farquhar) which is a lined holding pond constructed by Contact). Water from Lake Farquhar is currently discharged into the Wairākei Steam via the Drop Structure at the bottom end of the Geyser Valley.

2.4 CULTURAL HISTORY AND SETTING

Ngāti Tūwharetoa hold various Statutory Acknowledgements which, include the whole of the Wairākei-Tauhara Geothermal System on which Te Mihi Power Station is located, along with the land that is the subject of the current application to expand Te Mihi Power Station. The Statement of Association in relation to the Statutory Acknowledgement applying to the Wairākei-Tauhara Geothermal System states:

Ngātoroirangi

Ngātoroirangi was the tohunga (priest and navigator) of Te Arawa Waka. He inherited knowledge and mana from a number of priestly lineages including from Puhaorangi (Te Heketanga a Rangi), from his grandfather Tuamatua, and from te Whānau Ahi through his grandmother Waiheketua. Te Whānau Ahi were tohunga

2 Also spelt in various publications and maps (including the topographical map shown in Figure 1.1): Te

Kiriohineki Stream. 3 It is understood that Te Kiri o Hinekai Stream was historically geothermally influenced as a result of

geothermal inputs from the Alum Lakes area to the east of Te Mihi Power Station (i.e. further downstream). The upper reaches of the stream (to the west of the Alum Lakes area) have never been geothermally influenced (being an ephemeral stream in the upper reaches).


specialising in geological matters including knowledge of volcanism, geothermal activity and minerals.

After Te Arawa waka arrived in Aotearoa, Ngātoroirangi travelled inland from Te Awa o te Atua towards the peaks of the Central North Island. As he climbed Tongariro, he began to succumb to the cold southern wind. He called out to his sisters, Kuiwai and Haungaroa.

They called upon their ancestor Parawhenuamea and the twin spirits Te Pupu and Te Hoata were sent forth, swimming as two parallel streams of fire beneath the sea before rising at Whakaari, Tarawera, Rotorua, Ōrakei Kōrako, Wairākei, Tokaanu and eventually at Tongariro. When they arrived, they had one kete of geothermal energy remaining. Ngātoroirangi therefore named the spring Ketetahi (one kete).

Through the whakapapa and deeds of Ngātoroirangi, Ngāti Tūwharetoa are the descendants of geothermal taonga and have ancestral rights and responsibilities to the taonga and its active use and development as taonga tuku iho.

Wairākei

The Ngāti Tūwharetoa hapū, Ngāti Te Urunga, Ngāti Rauhoto, Ngāti Ruingarangi and Te Kapa o te Rangiita consider Wairākei to be the "jewel in the crown" of their rohe. It was likewise a taonga of Ngāti Kurapoto, an ancient hapū whose whakapapa is acknowledged within hapū of Te Hikuwai.

The name Wairākei refers to the beauty of the geothermal springs and natural features. It is also said that the name refers to Kuiwai, admiring herself in the still waters of the puna (springs). Wairākei is also the name of a tupuna. Ngāti Tūwharetoa considered the Wairākei geothermal field, stream and lakes as highly prized taonga tuku iho (ancestral treasure). The nearest kāinga and pā sites to Wairākei are along the Waikato River and at Nukuhau, Oruanui and Aratiatia.

Ngāti Tūwharetoa hapū used the resources and taonga at Wairākei extensively, including to cook, bathe and for medicinal purposes. The area contained many hot springs, mud pools and puna as well as a number of small and very colourful thermal lakes such as the Pīrorirori series of lakes. The Wairākei, Te Rau o Te Huia, Matarakutia and Te Kiri o Hinekai streams were considered to have very strong medicinal and healing properties. Ngāti Tūwharetoa and manuhiri who had travelled great distances would bathe in these thermal streams. Ngāti Tūwharetoa would also frequent Waipuwerawera, a thermal stream situated close to Nukuhau.

Ngāti Tūwharetoa gathered kōkōwai at Wairākei, which was highly prized for its pigments and used in ceremonial exchange with other iwi. Ōkurawai, Te Kiri o Hinekai stream and Pīrorirori lakes were significant sources of kōkōwai.

Karapiti is a large geyser at Wairākei. It is the place where Horomātangi blew with such force that he created the blowhole, signalling to Te Pupu and Te Hoata the way towards Tongariro.


Ngāti Tūwharetoa fought in a number of battles at Wairākei. The death of a great tupuna from another iwi killed in battle at Wairākei is commemorated in the name Te Mihi o Uenukukopako.

2.5 OTHER ENVIRONMENTAL CHARACTERISTICS

Other characteristics of the existing environment are described in the various technical reports attached as appendices to this AEE. This includes ambient noise, traffic, and the landscape and visual context.

2.6 THE EXISTING ENVIRONMENT – LEGAL CONTEXT

For the purposes of assessing the application by Contact for the expansion of Te Mihi Power Station, an assessment of effects on the “existing environment” needs to be undertaken (which is presented in Section 6 onwards of this AEE). Based on case law, the ‘existing environment’ includes the current environment as described above. However, of particular relevance to the current application, it also includes already consented activities that are not yet implemented, but are likely to be undertaken in future. Consideration of the “existing environment” also needs to take into account how the environment is expected to change over time, as provided for in the Taupō District Plan.

Key aspects in this regard are as follows:

Little change is anticipated in relation to the nature of surrounding land uses pursuant to permitted activity rules in the Taupō District Plan, apart from the ongoing development of steamfield activities on the Wairākei Field (which are able to occur as permitted activities within the Rural and Industrial Environments). The only possible change of potential relevance to the assessment of effects is the establishment of any new residential dwellings in proximity to the proposed expansion of Te Mihi Power Station. However, Rule 4e.15.1 in the Taupō District Plan requires a discretionary activity resource consent for any residential activities (apart from one dwelling house per lot) or accommodation activities or any subdivision of land in the vicinity (specifically as shown on Planning Map D1 in the Taupō District Plan). It is also noted that Sites THI A and THI B are further away from neighbouring properties than the existing Te Mihi Power Station.

Contact has the ability to build the third up to 90MW unit at Te Mihi in accordance with its Land Use Consent RM070304 (this being a partially unimplemented consent).

Ten Abbotts Limited holds resource consents (originally obtained by Geotherm Group Limited) for the construction and operation of a new geothermal power station and associated geothermal steamfield activities on Tukairangi Road to the south of the Poihipi Road Power Station. Given that the land to which these consents relate has been sold for lifestyle blocks including the land on which the power station was proposed (or is currently on the market as such), it is considered that there is no


prospect of those consents being implemented beyond the extent that has occurred to date (i.e. a well has been drilled and tested, but there is no real prospect of the proposed geothermal power station being constructed).


3. PROPOSED ACTIVITIES

The following provides a description of the activities that are the subject of the Land Use Consent Application set out in Part A of this document.

3.1 LOCATION OF FUTURE POWER PLANTS

The site locations for the expansion of the Te Mihi Power Station are presented in Part A of this document (Plans 1 and 2 in Schedule 1) and in Section 1 of this AEE (Figure 1.4).

3.1.1 Site THI A

Site THI A is only considered suitable for a steam turbine plant, not binary plant units. The footprint required at THI A has been graded (as part of the construction of Stage 1 of Te Mihi Power Station), but only limited work below ground has been undertaken, meaning all deep excavation and foundation works would still be required.

Any new unit on Site THI A may utilise some of the existing buildings and equipment (subject to detailed design), such as store/workshop, fire pumps, chemical storage and dosing, emergency generator and water treatment equipment and storage. There would also be similar plant outside the main turbine hall, such as control and switch/circuit breaker rooms and electrical transformers. Gas extraction equipment, steam separation vessels and pipework and rock mufflers would effectively replicate existing equipment, but scaled in physical size depending on the final unit capacity.

Site THI A has significant positive features including:

Close to the expanding and future production area to minimise steam transmission losses;

At the location of the two existing Te Mihi units and associated infrastructure;

Previously found to be suitable for dispersion of H2S discharged to atmosphere;

At a higher elevation than existing and future injection wells (Karapiti, Otupu and EBF), reducing injection pump power requirements; and

Ready access to the 220 kV electricity transmission grid (a third radius in switchyard is already available, and there is spatial allocation for a fourth inside the switchyard fence).

3.1.2 Site THI B

Site THI B is the preferred location for a multi-unit binary plant option, due to its larger footprint and its ability to avoid potential risks to public health and safety associated with the large amounts of flammable working fluid (cyclo-, iso- or n-pentane) used in binary plants. Power is generated in a binary plant by using geothermal fluids to heat a working fluid such as cyclopentane, which is a flammable substance similar in characteristics to


petrol. The cyclopentane is evaporated to create pressurised vapour, which is used to spin turbines and the associated generator. The exhaust is then cooled back to a liquid and returned to the start of the cycle in a closed system. Public health and safety issues associated with binary plants are addressed through the Health and Safety at Work (Major Hazard Facilities) Regulations 2016.

However, to minimise the consequences of a major hazard incident, the binary units would be located at least approximately 180 m to the south-east of the existing Te Mihi Power Station fence and would be about 1,000 to 1,500 m from the closest residences and public roads as shown in Figure 3.1 below. The potential effects of a major hazard incident on current or potential future neighbouring residential activities are discussed in Section 12 of this AEE.

Figure 3.1 – Site THI B Distances from Nearest Residences and Public Road

To prepare the platform in the THI B area, a significant volume of earthworks would be undertaken, calculated as approximately 315,000 m3 of cut and fill.

The concept design for the core platform is about 7 ha in size with a platform elevation of about 503 masl compared with 515 masl at the existing Te Mihi Power Station site (i.e. Site THI B would be about 12 m lower than the platform on which Stage 1 of Te Mihi Power Station is located). Figure 3.2 shows indicative balanced cut and fill needed to enable the platform, showing maximum cut of about 20 m and maximum fill of about 16 m. Any final design will aim to balance cut and fill to avoid import to, or export of, any material volume of soil. Figure 3.3 shows the platform shape and orientation for Site THI B.


Figure 3.2 – Site THI B Earthworks Layout

Figure 3.3 – Site THI B Shape and Orientation


3.2 TE MIHI ELECTRICITY GENERATION PLANT OPTIONS

Table 3.1 sets out a summary of the options (in terms of gross capacity, location, generation technology and cooling system) for the proposed expansion of Te Mihi Power Station. Option THI_0 is the third turbine unit consented by the BOI in 2008 (forming part of Consent RM070304) and is therefore part of the ‘existing environment’ for the purposes of assessing the effects of the options now being proposed.

Table 3.1 – Summary of Te Mihi Electricity Generation Plant Options

The following provides a description of each of the three generation plant options / configurations. Plans showing the location, layout and cross-section of each of the options are presented in Appendix 2.

3.2.1 Option 1 (THI_1)

Option 1 (THI_1) is single large steam turbine located within the existing consented footprint (Site THI A), with a gross output up to 180MW (see Drawings 9121 and 9122 in Appendix 2).

The turbine hall for the existing two 83 MW units is approximately 110 m long, 27 m wide, and 24.8 m high. The existing cooling towers are each about 132 m long, 16.5 m wide and about 15.6 m high, with eight cells, each with one fan.

It is unlikely that the turbine hall for plant Option 1 (maximum steam turbine capacity) would be higher than the existing turbine hall (24.8 m) and it will be no higher than originally consented.4 To accommodate the larger steam turbine, the turbine hall would be about 15 m longer than originally anticipated and currently consented, adding a total of about 75 m to the length of the existing turbine hall. Option 1 would require about 13 cooling tower cells making it up to about 220 m long, 17 m wide and a height of about 16.2 m which is lower than the current maximum consented5 cooling tower height of 19 m above the existing platform grade.

4 Not to exceed 542.4 masl above the existing finished platform grade at 515 masl (27.4 m) compared with the

existing turbine hall which extends to 539.8 masl (i.e. 24.8 m high). 5 Not to exceed 534.0 masl above the existing platform grade at 515 masl (19 m).


For Option 1, the required Low Pressure (“LP”) steam separators and some other equipment would likely be located to the east of the existing geothermal pipelines.

Some areas within the power station footprint, such as the main transformer area, would be protected with safety fencing while the remainder of the site would be within the existing security fence.


Option 2 (THI_2) consists of two smaller steam turbines, one on the existing consented footprint (Site THI A) and one further southeast (Site THI B), with a combined gross output up to 180MW (see Drawings 9125, 9126, 9127 and 9128 in Appendix 2).

The turbine hall for each of these plants would be about 58 m long by 27 m wide and about 25 m high. The associated cooling tower would be about 132 m long, 17 m wide and about 16 m high. On Site THI A, the plant would be an extension of the existing turbine hall with the same dimensions (and within the ambit of what is already consented). The second generating unit would be located on Site THI B and involve the same dimensions. For the smaller Option 2, the LP steam separators may be located to the west of the existing geothermal pipelines.


Option 3 (THI_3) consists of a Binary Plant, consisting of up to four units located on a new footprint to the southeast of the existing Te Mihi Power Station (Site THI B), with a gross output up to 165MW (see Drawings 9123 and 9124 in Appendix 2). Such plants operate using a hydrocarbon working fluid.

The major item of equipment for Option 3 is the Air Cooled Condensers (“ACC”) which are expected to consist of an ACC array of 60 fans (six across by ten longitudinally) per unit (240 fans in total) with an expected physical footprint of 60 m wide by 110 m long with a 7 m gap between each of the four units. The expected height of the ACC is about 14 m above finished platform grade. The turbine generators and heat exchangers will be about 65 m by 37 m.

New binary units in the THI B area would utilise some of the existing infrastructure, such as pipelines, existing Te Mihi Power Station administration building and stores and workshops etc. Some additional facilities, notably, a new fire system specifically designed for the presence of flammable working fluid and local control room would be constructed.

It is assumed (based on recent tender information of one of the suppliers for a similar plant), that the working fluid volume required by each of the four binary units is approximately 365m3, and an additional 175m3 per unit is held in each of four storage tanks. The internal binary side process conditions are conservatively assumed to be upstream pressure and temperature of 22.6 barg / 188.9°C. These details are subject to


change during plant development and design, but are considered very conservative (i.e. higher than expected). Like Site THI A, some areas within the station, such as the main transformers, would be protected with additional safety fencing while the remainder of the site would be within a new station security fence.

The platform location and orientation of the plant within Site THI B has been chosen to avoid known faults and associated buffer zones as identified by TDC and work undertaken by GNS for Contact in 2007, as shown in Figure 3.4.

A significant part of the proposed THI B platform is in a Hot Hazard Area identified in the Taupō District Plan. Preliminary investigations (see Appendix 4) indicate that Site THI B does not exhibit excess heat compared to ambient offsite conditions. Detailed geotechnical investigations will be undertaken during the development phase to ensure the detailed design of the foundations and structures during the construction phase is appropriate for the actual conditions encountered.

Figure 3.4 – Fault Lines (thin red lines) and associated 20 m buffers (yellow shaded) and Hot Ground Hazard Area (thick red line and red shaded area) within Site THI B

3.2.4 Combinations of Options

Options 1 and 2 (THI_1 and THI_2) are mutually exclusive, meaning only Options 1 or 2 would be built. Depending on the chosen capacity, Option 3 (THI_3) could be either mutually exclusive to Option 1 and Option 2, if all four units were built, or it could be built in combination with Option 2, if only one of the two ‘smaller’ steam turbine units were to be built.


Overall, the maximum generation plant capacity at Te Mihi will be limited by the maximum consented geothermal fluid take, and likely to be no more than 180MW.

3.3 KEY FEATURES OF THE PROPOSED EXPANSION OF TE MIHI POWER STATION

Key Features of the proposed expansion of Te Mihi Power Station are:

The additional units could add up to 180 MW to the Te Mihi site (1,450 GWh/a);

The station could produce about 70 MWnet (about 520 GWh/a) more than the existing Wairākei A & B Power Stations (compared with 2019 generation) from the same amount of mass extracted. This is because it would better utilise the geothermal resource and use the higher temperature part of the resource;

Operations personnel from Contact’s existing Geothermal Group Control (“GGC”) at Wairākei would support the new unit(s) as well as existing operations (Te Mihi units 1 and 2, Ohaaki, Poihipi Road, etc.);

Electricity generated at Te Mihi would be fed into the Wairākei-Whakamaru 220 kV transmission line, which has sufficient capacity for the additional generation; and

The plant would operate as a base-load station to supply power to the grid 24 hours a day, 7 days a week at an expected long-term average capacity factor of greater than 95%, comparing favourably with other renewable generation options such as wind, solar and hydro.

3.4 SWITCHYARDS AND ELECTRICITY TRANSMISSION

Transpower NZ Ltd owns and operates the existing switchyard located immediately north of Te Mihi Power Station. Electricity generated from the expansion of Te Mihi Power Station will be conveyed to this switchyard as follows:

In relation to any additional generation of electricity on Site THI A, there will be an underground 220 kV cable to the switchyard; and/or

In relation to any additional generation of electricity on Site THI B, there will be an overhead 220 kV power line from Site THI B to the switchyard. The proposed alignment of this power line is shown (as green lines) on Plan 1: Te Mihi Power Station Expansion – Land Use Consent Area in Schedule 1 of Part A of this document and on Figure 1.4. The power line will be on lattice or mono pole towers of up to 45 m high (similar to the transmission towers in the vicinity of Te Mihi Power Station).

3.5 SITE ACCESS

Access to Sites THI A and THI B will be via the existing point of access onto Oruanui Road. This access has been constructed to a high standard (sized to accommodate heavy commercial vehicles) and has controlled entry. There is a sealed two-lane road extending


from the entrance to Te Mihi Power Station. This access road will be used for the construction of any options on Site THI A.

If any of the power station options are constructed on Site THI B, a new section of internal sealed access road will be constructed to provide more efficient and direct access to the site as shown in Figure 3.5 (a larger scale version of this plan is presented in Appendix 2). The road will be approximately 696 m long and 7.5 m wide.

Figure 3.5 – Alignment of Internal Access Road to Site THI B

The construction of this new section of internal roading will involve approximately 13,000 m3 of cut and 5,000 m3 of fill. Cut to waste (approximately 8,000 m3 would be placed elsewhere within the Land Use Consent Area.

3.6 CONSTRUCTION ACTIVITIES

The main construction related activities are as follows:

Earthworks – there will be earthworks associated with the construction of the building platform, transmission towers, and new section of internal access road if Site THI B is utilised.

Plant Construction – construction of the electricity generation plant and associated structures.


Traffic Generation – there will be an increase in the level of traffic generation during the construction phase because of the construction workforce coming and going from the site and the delivery of machinery, plant, equipment and building materials. The level of traffic generation associated with the construction phase (and proposed mitigation measures) is discussed in the Integrated Transportation Assessment (Appendix 9).

Construction Laydown Areas – For any of the options constructed on Site THI A, the existing Construction Laydown Area located to the west of Te Mihi Power Station will be utilised. For any of the options constructed on Site THI B, Construction Laydown Areas will be formed within Site THI B.

Contractor Parking Area – For construction activities associated with Site THI A, the previous parking area (near the office building) used for the construction of Stage 1 of Te Mihi Power Station will be utilised. For construction activities associated with Site THI B, a parking area will be formed within Site THI B.

Noise – Higher levels of noise are typically experienced during construction activities. The level of noise generated is discussed in the Acoustical Assessment (Appendix 7).

3.7 PLANT OPERATIONS AND MAINTENANCE ACTIVITIES

Once any of the new electricity generation options are operational, there will be a similar number of staff based at Te Mihi Power Station as occurs at present (i.e. typically 8 people). They will utilise the existing carpark near the office, which has more car parks than necessary to meet demand.

Any expansion of Te Mihi Power Station will be controlled remotely from the GGC located at the Wairākei Power Station site, in the same manner that the existing Te Mihi Power Station is controlled and operated (and for Contact’s other power stations on the Wairākei-Tauhara Geothermal System).

Maintenance activities will occur on a scheduled and ‘as required’ basis. In particular, infrequent major outage activities have similar effects to construction activities but at a much lesser scale and duration.

3.8 FUTURE OF THE WAIRĀKEI A & B POWER STATIONS

As previously noted, Contact proposes to continue to maintain and operate some or all of the Wairākei A & B Power Stations until no later than 30 June 2031. No decision has been made by Contact regarding the future of the Wairākei A & B Power Station buildings and equipment once they cease to be used for the generation of electricity. The need or otherwise for any resource consents associated with the future decommissioning, demolition or re-purposing of the Wairākei A & B Power Stations will be determined nearer the time (and is beyond the scope of the current applications set out in Part A of this document).


4. RMA STATUS OF ACTIVITIES

The following sets out the status of the proposed activities under the RMA by reference to the rules and performance standards in the relevant planning documents.

4.1 TAUPŌ DISTRICT COUNCIL JURISDICTION

Figure 4.1 is the Planning Map in the Taupō District Plan relating to Te Mihi Power Station and the surrounding area, including zoning, overlays and features.

Figure 4.1 – Taupō District Plan - Planning Map

The existing Te Mihi Power Station Site is partly in the Industrial Environment (shaded grey on Figure 4.1) and partly in the Rural Environment (shaded green on Figure 4.1). In general, the parts of Te Mihi Power Station sitting in the Industrial Environment include most of the existing two cooling tower structures, the switchyard and parts of the Te Mihi steamfield, while the main turbine hall, steamfield geothermal fluid holding pond, various other


ancillary buildings and other parts of the Te Mihi steamfield are located in in the Rural Environment.

The vast majority of Site THI A is within the Rural Environment. There is a very small triangle of land (to the south of the existing cooling towers) zoned Industrial Environment which extends into Site THI A. Most of Site THI B is within the Rural Environment. Approximately 25% of Site THI B is within the Industrial Environment. The proposed internal access road to Site THI B is within the Rural Environment. The route of the overhead 220kV transmission line from Site THI B to the existing switchyard is partially within the Rural Environment and partially within the Industrial Environment.

Other observations about the current Te Mihi Power Station site and its surrounds are:

The entire Te Mihi Power Station site (existing and proposed) is outside the Electricity Generation Core Site6;

A Noise Control Boundary (shown as a thick jagged grey line) surrounds the Te Mihi Power Station Site, however it only relates to activities within the Electricity Generation Core Site, which (as noted above) is not applicable to the Land Use Consent Area for the proposed expansion of Te Mihi Power Station;

The site is bounded to the east and west by two Fault Lines identified in the Taupō District Plan (Sites THI A and THI B have been selected to avoid known fault lines – being those shown on the planning map in the Taupō District Plan and others more recently identified by GNS);

The northern boundary of the Wairākei Tourist Park (shown as a purple dotted and dashed line on Figure 4.1) passes through Te Mihi Power Station site including Site THI A. This is of no consequence in terms of any planning provisions;

The eastern half (approximately) of Site THI B is located within a Hot Ground Hazard Area;

There are no Outstanding Landscape Areas, Amenity Landscape Areas or Significant Natural Areas located within the Te Mihi Power Station Site including Sites THI A and THI B;

A Significant Natural Area (SNA 037) is located approximately 90 m to the east of Site THI B;

Designation D112 (Wairākei to Whakamaru C Line) is located to the north of Te Mihi Power Station;

6 This is due to Te Mihi Power Station being consented and constructed after Electricity Generation Core Sites

were mapped in the Taupō District Plan.


The existing turbine hall is approximately 620m to the nearest dwelling (located to the north-west); and

The Poihipi Road Power Station, located approximately 1 km to the southwest of Te Mihi Power Station, is zoned Industrial Environment.

A detailed analysis of the relevant rules and performance standards in the Taupō District Plan relating to the activities that are the subject of the application in Part A of this document is presented in Appendix 3. Of relevance to the analysis presented in Appendix 3, an assessment of the Hot Ground Hazard Area, relating to the eastern half (approximately) of Site THI B, has been undertaken by GNS (see Appendix 4). The results of the analysis presented in Appendix 3 (and Appendix 4) are as follows.

4.1.1 Rural Environment

The proposed expansion of Te Mihi Power Station exceeds the following permitted activity performance standards relating to the Rural Environment in the Taupō District Plan:

Rule 4b.1.1 – Maximum Building Height

Rule 4b.1.2 – Maximum Building Coverage

Rule 4b.1.4 – Minimum Building Setbacks – All Other Boundaries

On the basis of the above, the proposed expansion of Te Mihi Power Station is a Discretionary Activity under Rule 4b.2.9 in the Taupō District Plan.

4.1.2 Industrial Environment

The proposed expansion of Te Mihi Power Station (specifically in relation to a small part of Site THI A) exceeds the following permitted activity performance standard relating to the Industrial Environment in the Taupō District Plan:

4d.1.5 - Minimum Building Setback

On the basis of the above, the proposed expansion of Te Mihi Power Station is a Restricted Discretionary Activity under Rule 4d.2.3 in the Taupō District Plan.

4.1.3 District Wide Performance Standards

The proposed expansion of Te Mihi Power Station (specifically in relation to Site THI B) exceeds the following permitted activity District Wide Performance Standards in the Taupō District Plan:

4e.12 - Hot Ground Hazard Area

4e.14 - Network Utilities


The proposed activities within the Hot Ground Hazard Area are a Discretionary Activity under Rule 4e.12.5 in the Taupō District Plan.

The triggering of Rule 4e.14 (in relation to the proposed 220 kV transmission line) results in Discretionary Activity Status under Rule 4e.14.8 in the Taupō District Plan.

4.1.4 Overall Land Use Status

In summary, applying the ‘bundling’ approach (whereby the most restrictive land use status is applied to all aspects of a proposal), the proposed expansion of Te Mihi Power Station is a Discretionary Activity under the rules in the Taupō District Plan.

Three other matters within the jurisdiction of TDC need to be addressed, as discussed in the following sections.

4.1.5 Land Use Status of New Wairākei Geothermal Power Station

Section 1.4 of this AEE outlines the key aspects of the overall GeoFuture Project, of which the expansion of Te Mihi Power Station is a major component. It also mentions the possibility of a new small (up to 40 MW) geothermal power station being constructed on the Wairākei Power Station Site (utilising geothermal fluid from the WBF) which cannot practically be conveyed (uphill) to the Te Mihi Power Station. The latter is a Permitted Activity within the Industrial Environment that relates to the Wairākei Power Station Site and is the subject of a Certificate of Compliance granted by TDC7. That aspect of GeoFuture is therefore beyond the scope of the current application to TDC for a Land Use Consent in relation to the expansion of Te Mihi Power Station.

4.1.6 National Environmental Standard for Soil Contamination

The Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (“NES-CS”) came into effect on 1 January 2012. It applies if an activity or industry described in the Hazardous Activities and Industries List (“HAIL”) is undertaken, has been undertaken, or more likely than not, is being or has been undertaken on the land.

Regulation 5(1) of the NES-CS, sets out where the regulations apply, as follows:

(1) These regulations;

(a) apply when a person wants to do an activity described in any of subclauses (2) to (6) on a piece of land described in subclause (7) or (8).

(b) Do not apply when a person wants to do an activity described in any of subclauses (2) to (6) on a piece of land described in subclause (9).

7 Reference: RM210176.


Disturbing the soil (i.e. earthworks) forms part of the application by Contact set out in Part A of this document which is an activity specified in Regulation 5(4) of the NES-CS.

Land covered by the NES is specified in Regulations 5(7) and 5(8) of the NES-CS, as follows:

(7) The piece of land is a piece of land that is described by 1 of the following:

(a) an activity or industry described in the HAIL is being undertaken on it:

(b) an activity or industry described in the HAIL has been undertaken on it:

(c) it is more likely than not that an activity or industry described in the HAIL is being or has been undertaken on it.

(8) If a piece of land described in subclause (7) is production land, these regulations apply if the person wants to—

(a) remove a fuel storage system from the piece of land or replace a fuel storage system in or on the piece of land:

(b) sample or disturb—

(i) soil under existing residential buildings on the piece of land:

(ii) soil used for the farmhouse garden or other residential purposes in the immediate vicinity of existing residential buildings:

(iii) soil that would be under proposed residential buildings on the piece of land:

(iv) soil that would be used for the farmhouse garden or other residential purposes in the immediate vicinity of proposed residential buildings:

(c) subdivide land in a way that causes the piece of land to stop being production land:

(d) change the use of the piece of land in a way that causes the piece of land to stop being production land.

In relation to Regulation 5(7), Section B4 of the HAIL includes:

“Power stations, substations or switchyards”.

The ‘pieces of land’ on which activities are proposed do not have a power station, substation or switchyard on them at present (and nor have they in the past).

A Preliminary Site Investigation (“PSI”) has been undertaken (see Appendix 12). The PSI concludes that a consent is not required from TDC under the NES-CS associated with the proposed expansion of Te Mihi Power Station.

4.1.7 National Environmental Standard for Electricity Transmission

Section 4e.14 of the Taupō District Plan refers to the Resource Management (National Environmental Standards for Electricity Transmission Activities) Regulations 2009 (“NES-ETA”). A new section of 220 kV transmission line is proposed to link the generation units


to the switchyard on the Te Mihi Power Station Site. However, the NES-ETA is not relevant to this aspect of the proposal. Regulation 4(1) of the NES-ETA states:

“These regulations apply only to an activity that relates to the operation, maintenance, upgrading, relocation, or removal of an existing transmission line …”

4.2 WAIKATO REGIONAL COUNCIL JURISDICTION

Contact holds a comprehensive suite of resource consents which enable activities associated with the construction and operation of the proposed expansion of the Te Mihi Power Station. These consents expire on 30 June 2026. These consents include the following activities:

Take and discharge of geothermal fluid;

Take and discharge of fresh water for cooling purposes; and

Discharges to air.8

Contact is currently undertaking environmental investigations and consultation with interested and potentially affected parties as part of the process of preparing applications to WRC for new resource consents to replace the ones that expire in 2026. This will include an application for an Air Discharge Permit for any expansion of the Te Mihi Power Station beyond that which is authorised by the consents granted by the BOI in 2008. These applications will be lodged with WRC at a later date (expected to be by the end of 2021) following the current Land Use Consent Application to TDC for the proposed expansion of the Te Mihi Power Station.

Apart from an Air Discharge Permit, no additional resource consents are required from WRC for the expansion of Te Mihi Power Station. In relation to earthworks, Site THI B is not a High Risk Erosion Area and the performance standards in Rule 5.1.5 of the Waikato Regional Plan will be able to be complied with, whereby any earthworks are a Permitted Activity in accordance with Rule 5.1.4.11 of the Waikato Regional Plan. While it is not anticipated at this stage, if a consent is required for cleanfill (e.g. the importation of sand or aggregate) following detailed design (whereby cleanfill exceeds 2,500 m3 / annum), an application will be lodged with WRC at that time. Such an application would be a Controlled Activity under Rule 5.2.5.5 of the Waikato Regional Plan.

4.3 JOINT APPLICATIONS

It is normal practice to apply for all resource consents associated with a proposed development at the same time. However, in this instance, Contact is applying for the Land

8 The Air Discharge Permit relating to the Te Mihi Power Station includes three units, two of which have

been installed. A new Air Discharge Permit is required for discharges to air associated with any expansion of Te Mihi Power Station that is beyond what is authorised by the existing resource consents.


Use Consent for the expansion of Te Mihi Power Station as a standalone application ahead of the suite of resource consent applications that will be lodged with WRC at a later date (expected to be by the end of 2021) relating to all aspects of the ongoing operation of the Wairākei Field within WRC’s jurisdiction.

This approach has been adopted at the request of TDC on the basis that the environmental issues associated with the expansion of Te Mihi Power Station within TDC’s jurisdiction are very limited in scope and magnitude. Furthermore, TDC saw no merit in being involved in a joint process that will be primarily focused on a much wider range of environmental issues beyond its jurisdiction that will be traversed in the context of the applications to WRC. Dealing with the applications separately was also discussed with WRC and no objections to this approach were raised.


5. ASSESSMENT OF APPLICATIONS

As a Discretionary Activity, the proposed expansion of Te Mihi Power Station needs to be considered and assessed in relation to the following sections of the RMA.

5.1 SECTION 104 OF THE RMA

Section 104 of the RMA specifies the matters that a consent authority must ‘have regard to’ when considering applications for resource consents, as follows:

104 Consideration of applications

(1) When considering an application for a resource consent and any submissions received, the consent authority must, subject to Part 2 have regard to-

(a) any actual and potential effects on the environment of allowing the activity; and

(ab) any measure proposed or agreed to by the applicant for the purpose of ensuring positive effects on the environment to offset or compensate for any adverse effects on the environment that will or may result from allowing the activity; and

(b) any relevant provisions of –

(i) a national environmental standard:

(ii) other regulations:

(iii) a national policy statement:

(iv) a New Zealand coastal policy statement:

(v) a regional policy statement or proposed regional policy statement:

(vi) a plan or proposed plan; and

(c) any other matter the consent authority considers relevant and reasonably necessary to determine the application.

The above matters in section 104 of the RMA are addressed in the following sections of this AEE.

5.2 SECTION 104B OF THE RMA

Section 104B of the RMA applies to Discretionary Activities. It states:

104B Determination of applications for discretionary or non-complying activities

After considering an application for a resource consent for a discretionary activity or noncomplying activity, a consent authority—

(a) may grant or refuse the application; and

(b) if it grants the application, may impose conditions under section 108.


Section 108 of the RMA (referred to in section 104B quoted above) sets out the nature of conditions that a consent authority may include on a resource consent. A consent authority is entitled to have regard to any proposed conditions (and legally must assume those conditions will be complied with) as part of the assessment of the applications. A set of proposed consent conditions is discussed in Section 18 and presented in Appendix 14.


6. POSITIVE EFFECTS

6.1 ECONOMIC BENEFITS

Contact engaged Concept Consulting Group Limited to prepare an Economic Benefit Assessment in relation to the overall GeoFuture Project, a major component of which is the construction and operation of Stage 2 of the Te Mihi Power Station (the subject of the current application). The Economic Benefit Assessment is presented in Appendix 5. The references in the report to “new GeoFuture power stations” refers to the proposed expansion (Stage 2) of Te Mihi Power Station and the possible development of a smaller (up to 40 MW) geothermal power station on the Wairākei Power Station Site which would be commissioned at the time of, or following, the closure of the Wairākei A & B Power Stations. As previously noted, the latter is a Permitted Activity within the Industrial Environment that relates to the Wairākei Power Station Site and is the subject of a Certificate of Compliance granted by TDC.

The Executive Summary of the Economic Benefit Assessment is as follows:

Current position

The Wairakei Geothermal Field currently supports power generation at the following facilities:

1. Te Mihi Station – this station was commissioned in 2014 and currently generates around 1,320 GWh/year.

2. Poihipi Station – this station commenced operation in 1997 and generates around 380 GWh/year.

3. Wairakei Binary Plant (WBP) – this plant was commissioned in 2005 and generates around 90 GWh/year.

4. Wairakei A&B Station – this facility commenced operation in 1958 and currently produces about 930 GWh/year.

These facilities operate under resource consents which govern (among other matters) the total geothermal fluid take from the Wairakei Field. The current consents allow a maximum annual average daily take of 245 kt/day. These consents expire in 2026.

Proposed Consents

Contact is seeking new consents which would enable:

1. The existing Te Mihi, Poihipi and Wairakei Binary Plant (WBP) facilities to continue to operate from 2026-20579.

9 This assumes the decision on the consent application is made by the end of 2022, and consents are granted

for a term of 35 years from 2022.


2. The development and operation of the new GeoFuture power stations with an expected commissioning date between 2026 and 2031. The new plant may produce up to around 1,450 GWh/year of electricity, which would produce a net increase of up to 520 GWh/year compared to the existing Wairakei A&B station.

3. The continued operation of the Wairakei A&B Power Station until the GeoFuture plant comes into operation (or 2031 at the latest).

The overall Wairakei Field fluid take in the proposed consents is 250kt/day (around 2% higher than the existing consents).

Economic Benefits of Granting Consent

Granting the consents is expected to have significant economic benefits for New Zealand and the region.10 First, granting of consents would allow continued operation of the Te Mihi, Poihipi and Wairakei Binary Plant facilities. These facilities generate sufficient power to meet the energy needs of more than 250,000 households. We expect economic benefits to New Zealand of around $808 million in present value terms from continued operation of these plants. These benefits stem from avoided investment costs in replacement renewable plants that would otherwise be required.

Second, granting of consents would allow the GeoFuture power stations to be developed to replace the Wairakei A&B plant. The GeoFuture stations would generate sufficient power to meet the energy needs of around 207,000 households – a net increase of 70,000 households compared to the Wairakei A&B plant. This is possible with only a modest (around 2%) increase in geothermal fluid take because the GeoFuture plant would be much more efficient in energy conversion than the Wairakei A&B station. We expect that allowing the GeoFuture plant to proceed would produce economic benefits to New Zealand of up to $70 million in present value terms. These benefits stem from the cost savings attributable to this plant, compared to the likely next best power generation alternative (i.e. alternative new geothermal and/or wind generation).

Third, we expect that providing flexibility to allow a seamless transition from Wairakei A&B to GeoFuture between 2026 and 2031 will yield benefits of up to $16 million in present value terms. This benefit arises because it allows Contact to optimise the transition date from the Wairakei A&B to GeoFuture in this window. This flexibility is particularly beneficial at present due to heightened uncertainties over future power demand caused by Covid-19, potential Tiwai smelter closure, and the uptake trajectory for electric vehicles and industrial process electrification. In addition, we expect that providing some flexibility over the transition date will

10 We have developed quantitative estimates of national benefits from electricity sector effects. We have not

quantified non-electricity sector effects although we discuss them in qualitative terms.


reduce greenhouse gas emissions by up to approximately 540,000 tonnes of carbon dioxide equivalent, all other factors being equal.

Finally, we expect that allowing the GeoFuture development to proceed will produce benefits to the Waikato Region of $520 million to $600 million in revenue terms during the construction phase. Likewise, we expect the ongoing operations of the Te Mihi, Poihipi, Wairakei Binary Plant and GeoFuture plants will yield Waikato Region benefits of nearly $50 million per year in revenue terms over their lifetimes.

6.2 DECARBONISING THE ECONOMY

The Economic Benefit Assessment (discussed above) quantifies the reduction in greenhouse gas emissions associated with the flexibility sought by Contact to allow a seamless transition from Wairākei A & B Power Stations operation to GeoFuture between 2026 and 2031. This is part of a wider effort on the part of Contact to assist with the decarbonisation of the New Zealand economy.

In 2008, 55% of Contact’s electricity generation portfolio was from renewable sources. Since then, Contact has increased the proportion of its electricity generation from renewable sources to 84%. This has been achieved as result of the following actions (all of which have, and/or are, assisting with the decarbonisation of the New Zealand economy):

In 2008, Contact closed the 600 MW New Plymouth Thermal Power Station;

In 2010, Contact opened the 23 MW Te Huka Geothermal Power Station;

In 2014, Contact opened the 166 MW Te Mihi Geothermal Power Station;

In 2015, Contact closed the 404 MW Otahuhu B Thermal Power Station (and decided not to construct the consented 400 MW Otahuhu C Thermal Power Station); and

Contact is currently constructing the 152 MW Tauhara Geothermal Power Station (planned to be completed in mid-2023).

When the Tauhara Geothermal Power Station is commissioned, 95% of the electricity generated by Contact will be from renewable sources.

GeoFuture is Contact’s next step in terms of assisting with the decarbonisation of the New Zealand economy. As previously noted, the GeoFuture power stations (of which the expansion of Te Mihi Power Station is the largest component), will generate sufficient power to meet the energy needs of around 207,000 households – a net increase of up to 70,000 households compared to the Wairakei A & B Power Stations generation. It will achieve that with only a modest (around 2%) increase in geothermal fluid take because the GeoFuture plant would be more efficient in energy conversion than the Wairakei A & B Power Stations and because it utilises a higher proportion from the higher temperature part of the field.


7. LANDSCAPE AND VISUAL EFFECTS

Contact engaged Isthmus to prepare a Landscape and Visual Assessment in relation to the construction and operation of Stage 2 of the Te Mihi Power Station. The Landscape and Visual Assessment is presented in Appendix 6. The Executive Summary of the Landscape and Visual Assessment is as follows:

A 2008 Board of Inquiry (BOI) decision11 provided for the development of the Te Mihi Geothermal Development site at the head of the Wairākei Geothermal Valley.

The Te Mihi area has a working rural character, including the existing geothermal electricity development platform, pipeline(s) and electricity transmission lines.

The GeoFuture development proposals for the Te Mihi Geothermal Development site includes expansions of the existing steam turbine generation system (Options THI_1 and THI_2) or the development of a binary plant on a lower platform further to the east of the site (Option THI_3).

The THI_1 and THI_2 options for development on the Te Mihi Geothermal Development site include extension and expansion of an existing family of structures and buildings on the same platform.

Option THI_3 introduces a new type of geothermal electricity development on a different platform.

The development of Options THI_1 or THI_2 on the existing geothermal development platform (THI A) and expansion to the site to the east (THI B) would not have any adverse effects on the landscape character of the Te Mihi area.

The development of Option THI_3 would have very low, that is, less than minor, adverse effects on the landscape character of the Te Mihi area.

The development of Options THI_1 or THI_2 would have no adverse effects on the visual amenity of the Te Mihi area.

Development option THI_3 would not be visible from any public location close to the area and would have no adverse effects on the visual amenity of the location.

The 2008 Board of Inquiry Decision provides for additional generation capacity at the Te Mihi Geothermal Development site, which can be accommodated and extended through the development of Options THI_1, THI_2 or THI_3 without having any adverse effect on the visual amenity and a very low effect on landscape character of Te Mihi.

The development of Option THI_1, THI_2 or THI_3 on the Te Mihi Geothermal Development platform would be consistent with the Regional and District Planning

11 Final Report and Decision of the Board of Inquiry. Te Mihi Geothermal Power Station Proposal. September

2008.


framework for geothermal development and Industrial and Rural landscape management in the Te Mihi area.

Despite the conclusions reached in the Landscape and Visual Assessment (that the expansion of Te Mihi Power Station will have no, or less than minor, adverse effects on the landscape and visual amenity of the Te Mihi area), Contact has proposed consent conditions (presented in Appendix 14) which require a full review of the landscaping undertaken as part of Stage 1 of Te Mihi Power Station. The conditions require an updated Landscape Management Plan be prepared. Part of the preparation of this Plan will be a review of the adequacy of the landscaping implemented and maintained to date and to specify any additional landscaping required to mitigate any cumulative visual effects associated with Stage 2 of Te Mihi Power Station development.


8. NOISE EFFECTS

Contact engaged Pro-Acoustics GmbH to prepare an Acoustical Assessment in relation to the construction and operation of Stage 2 of the Te Mihi Power Station in combination with noise from the existing Stage 1. The Acoustical Assessment is presented in Appendix 7.

The Acoustical Assessment notes that the relevant performance standards relating to noise limits specified for activities within the Rural Environment are as follows:

4b.1.8 Maximum Noise Measurement

The noise levels shall be measured in accordance with the requirements of NZS 6801:1999 Acoustics – Measurement of Environmental Sound and assessed in accordance with the requirements of NZS6802:1999 Assessment of Environmental Sound.

4b.1.9 Maximum Noise Limits

The noise level arising from any activity measured within the notional boundary of any rural environment site or within the boundary of any residential environment site, other than the site where the noise is generated, shall not exceed the following limits:

i. 7.00am – 10.00pm 55dBA Leq

ii. 10.00pm – 7.00am 40dBA Leq and 70dBA Lmax

EXCEPTIONS: for specific noise refer to following Performance Standards:

4b.1.10 Maximum Noise Construction Noise

All construction noise shall meet the requirements of New Zealand Standard NZS 6803:1999 Acoustics – Construction Noise.

The noise limits in the Rural Environment are more restrictive than those relating to the Industrial Environment and the former have been adopted for the purposes of noise limits in the proposed consent conditions presented in Appendix 14.

In relation to construction noise, the Acoustical Assessment concludes:

The construction of the new geothermal power station will be able to comply with Rule 4b.1.10 relating to construction noise.

All construction noise shall meet the requirements of New Zealand Standard NZS 6803:1999 Acoustics – Construction Noise. The limits of table 2 of the standard will be applied during construction and commissioning of the plant.


The overall conclusion in the Acoustical Assessment states:

Pro-Acoustics GmbH has carried out an Acoustical Assessment of different options for the extension of the Te Mihi Power Station.

In this document the different options were evaluated with regards to acoustical impact at the identified nearest noise sensitive locations.

The results from the noise prediction calculations show that it is possible to achieve compliance with the noise limits specified in the Taupo District Plan at all identified nearest receivers.

The values presented in this report have been determined using the acoustical model Status April 2021.

Figure 8.1 is a diagram (referred to as a noise thermometer) which helps put noise levels in perspective and is relevant to the following discussion.

Figure 8.1 – Noise Thermometer


In terms of operational noise levels (post construction), the expanded Te Mihi Power Station needs to achieve the night-time noise limit of 40dBA Leq. The noise limit of 40dBA Leq at night-time is to ensure that noise levels do not create sleep disturbance. The Acoustical Assessment concludes that none of Contact’s neighbours will experience noise levels from Te Mihi Power Station (i.e from both the existing Stage 1 and proposed Stage 2) greater than 40dBA Leq. However, that does not mean that the power station cannot be heard, it will be audible at times.

The following table sets out the subjective reaction and level of impact in relation to changes in noise levels. In the case of the current proposal, the greatest level of increase in noise level that will be experienced by the closest of Contact’s neighbours will be less than a 4 dBA increase compared with the existing situation (which in those instances is currently between 30 and 35 dBA). The human ear cannot detect a change of less than 3 dBA. An increase of 3 – 4 dBA is just perceptible and will only have slight / minor effect.

Table 8.1 – Reactions and Level of Impact to Changes in Noise Levels

Change in Sound Level (dBA)

Subjective Reaction Impact / RMA Adverse Effect

1 - 2 Imperceptible change Negligible/less than minor

3 - 4 Just perceptible change Slight/Minor

5 - 8 Appreciable change Noticeable

9 - 11 Doubling of loudness Significant/Substantial

> 12 More than a doubling of loudness Severe

Given that noise associated with the existing Te Mihi Power Station has been an issue of concern to some of Contact’s neighbours in the Oruanui Road area, Contact engaged Marshall Day Acoustics to undertake an independent peer review of the Acoustical Assessment prepared by Pro-Acoustics GmbH (see Appendix 8). Key aspects of the peer review undertaken by Marshall Day Acoustics are reproduced as follows:

Marshall Day Acoustics (MDA) has been retained by Contact Energy Ltd (Contact) to peer review work by PRO Acoustics (PRO) with regard to the proposed extension to Te Mihi Power station (TMP).

In particular, the proposal is for new geothermal power generation to be added to the TMP which was granted land use consent by Board of Inquiry (BOI) decision dated 3 September 2008.

The purpose of the peer review is to give certainty to the local authority that predicted noise levels by PRO are credible. MDA policy states that we must complete our own full calculation exercise in order to fully validate potential noise levels from a project. The veracity of the predicted noise levels will allow Council


to be informed with regard to issuing a land use consent for additional power generation at TMP.

We are able to assess information provided by PRO to give an opinion about the veracity of the predicted noise levels. This will provide Contact and Council confidence about the actual or potential noise from the proposed TMP development.

Marshall Day Acoustics concludes:

The acoustic review of the PRO report concludes that noise levels have been calculated in general accordance with the appropriate standards for environmental sound.

The predicted noise from the addition of any one of four different potential configuration options and technologies to existing TMP noise emission is anticipated to comply with noise limits that will ensure acoustic amenity at existing houses is maintained and protected.

The relevant noise limits have been correctly identified. Compliance with these – as required in condition 33 [of the 2008 BOI Decision] … is considered appropriate to ensure amenity at houses is protected. The noise limits specified in condition 33 are identical to Taupo District Plan 4b.1.9 which relates to noise received within the rural environment.

Contact has proffered consent conditions that require compliance with the applicable noise limits specified in Rules 4b.1.9 and 4b.1.10 in the Taupō District Plan (see Section 18 and Appendix 14).


9. TRANSPORTATION EFFECTS

Contact engaged CKL to prepare an Integrated Transportation Assessment (“ITA”) in relation to the construction and operation of Stage 2 of the Te Mihi Power Station. The ITA is presented in Appendix 9. The Executive Summary of the ITA is as follows:

This Integrated Transportation Assessment (ITA) has been prepared to assess the effects of traffic associated with the second stage of construction of the previously consented Te Mihi Geothermal Power Station (‘the site’).

The site is located approximately 9km north-west of Taupo, in a largely rural environment. The site is located on the eastern side of Oruanui Road, approximately 650m north of the intersection of Poihipi Road with Oruanui Rd.

This assessment is focussed on the potential construction traffic effects arising from the use of this external site access to Oruanui Road, and the wider locality, where Oruanui Road intersects with other roads, which will become common routes to the site entrance (notably Poihipi Road, State Highway 1, Link Road and Wairakei Drive).

The subject site is located within Taupo District Council’s jurisdiction, and has been assessed against the relevant transportation criteria of the Taupo District Plan.

Stage 1 of the power station has been consented and approved. The construction traffic assessed in this report is for Stage 2 of the power station. Two power generation options are being considered for Stage 2 by Contact Energy. These are either the use of a steam turbine or a binary plant.

The overall length of construction is anticipated to be 27 months, operating typically six days a week, ten hours a day. The peak period of construction is expected to be during the civil and structural installation phase. For Stage 1, this took approximately 17 months throughout the middle of the construction period. The civil and structural installation phase is expected to occur 2-3 months after the project begins. There are expected to be 350-400 staff operating on site.

The binary plant option is expected to produce less traffic than the steam turbine option given that the foundations and structures for the binary option are much simpler than for the steam turbine option. This ITA therefore assesses the effects of the steam turbine option only given that it would result in more traffic movements than the binary plant option.

The proposed construction traffic for Stage 2 is expected to be approximately 70% of the traffic compared to Stage 1. This is a reduction from 64vpd to 45vpd and a reduction from 4-8vph to 3-6vph during the peak hour.

Traffic volumes have decreased on Wairakei Drive given that it is no longer a State Highway. In conjunction with the lower construction traffic for Stage 2 and intersection upgrades made to the Wairakei Drive and Poihipi Road intersection as


a part of Stage 1, the Stage 2 construction traffic is not expected to adversely impact the performance or capacity of this intersection.

The site access was upgraded as a part of Stage 1 and is considered appropriate to accommodate the proposed Stage 2 construction traffic. This access meets minimum sight distance and separation distance standards required by the District Plan.

It is expected that the following intersections would be used for construction traffic:

• Oruanui Road and SH1.

• Oruanui Road and Link Road.

• Link Road and SH1.

• Poihipi Road and Oruanui Road.

• Poihipi Road and Wairakei Drive.

A review of these intersections indicates that they are able to accommodate the proposed construction traffic volumes.

There is sufficient area on site for temporary parking and loading of the proposed construction traffic. No changes are proposed to the consented activity requiring additional permanent car parking.

The proposal is unlikely to have a detrimental effect on road safety.

NZTA has been consulted and no concerns have been raised.

The proposal complies, or can comply, with all transport related rules in Chapter 6 of the District Plan.

It is recommended as a condition of consent that a CTMP is submitted and approved by Taupo District Council prior to construction occurring.

The proposal is considered to have less than minor traffic effects and no physical mitigation works are required to accommodate this temporary traffic demand on the road network.

Consent conditions have been proffered by Contact which reflect the recommendations in the ITA (see Section 18 and Appendix 14).


10. ARCHAEOLOGICAL EFFECTS

Contact engaged Clough and Associates to prepare an Archaeological Assessment in relation to the area in which construction and operation of Stage 2 of the Te Mihi Power Station is proposed. The Archaeological Assessment is presented in Appendix 10. The Conclusions and Recommendations presented in the Archaeological Assessment are as follows:

Conclusions

No archaeological or other historic heritage sites have been identified within the project area of the proposed Te Mihi power station extension. The development will therefore have no known effects on archaeological values.

The potential for unidentified subsurface archaeological sites to be present is considered to be very low, but the possibility cannot be completely excluded.

Recommendations

• There should be no constraints on the proposed development of a third geothermal power station on archaeological grounds, since no archaeological sites are known to be present and it is considered unlikely that any will be exposed during development.

• If subsurface archaeological evidence should be unearthed during construction (e.g. intact shell midden, hangi, storage pits relating to Maori occupation, or cobbled floors, brick or stone foundation, and rubbish pits relating to 19th century European occupation), work should cease in the immediate vicinity of the remains and Heritage NZ and the Council should be notified.

• If modification of an archaeological site does become necessary, an Authority must be applied for under Section 44(a) of the HNZPTA and granted prior to any further work being carried out that will affect the site. (Note that this is a legal requirement).

• In the event of koiwi tangata (human remains) being uncovered, work should cease immediately in the vicinity of the remains and the tangata whenua, Heritage NZ, NZ Police and Council should be contacted so that appropriate arrangements can be made.

• Since archaeological assessment will not necessarily identify sites of traditional significance to Maori, such as wahi tapu, the tangata whenua should be consulted regarding the possible existence of such sites on the property.

Consent conditions have been proffered by Contact which reflect the recommendations in the Archaeological Assessment (see Section 18 and Appendix 14). This includes a requirement to adhere to a Cultural / Archaeological Sites Protocol attached as Schedule 2 to the proposed consent conditions (this being the same document that forms part of the conditions relating to Consent RM070304 authorising the existing Te Mihi Power Station).


11. CULTURAL VALUES

A Cultural Impact Assessment dated 14 November 2007 (“CIA”) was prepared by Gayle Leaf and Dr Charlotte Severne on behalf of Ngāti Te Kapa o Te Rangiiat ki Ōruanui as part of the original applications for the Te Mihi Power Station. The discussion, findings and recommendations in the CIA about the relationship of iwi and hapū to the geothermal taonga, ancestral lands, wāhi tapu, waters and other resources have been considered by Contact during the development of the GeoFuture proposals and in particular, the expansion of Te Mihi Power Station.

Contact acknowledges that iwi and hapū have a close relationship to their geothermal taonga and hold important cultural and spiritual values related to geothermal resources and surface features. The range of cultural values associated with geothermal resources include their customary values, such as their use for bathing, cooking, washing, trading, and medicinal purposes. There are also contemporary values such as the use of geothermal resources for electricity generation, local employment, economic development and other industries utilising direct or cascade geothermal heat.

The cultural and spiritual effects associated with the use of and effects on geothermal resources, surface features and vegetation, the Waikato River and streams, cultural sites and whenua across the Wairākei consent area, are all matters that are currently being engaged on and will be addressed in the context of Contact’s applications to WRC for the take, use and discharge of geothermal water and energy and associated activities. The applications to WRC are proposed to be lodged with WRC by the end of 2021.

Section 4e.4 of the Taupō District Plan sets out the following assessment criteria which “shall be taken into consideration where appropriate” during the assessment of a resource consent application:

a. Where there are any sites of significance to Tangata Whenua (whether identified

in the Plan or not), and the potential effect of the activity on the cultural value of

the site.

b. Any alternative locations available for the activity, or whether the activity can be

undertaken without adversely affecting the site of significance to Tangata

Whenua.

c. Whether proposed mitigation measures to be undertaken as a result of the

activity protects or preserves the value and/or significance of the site.

d. The relationship of a site of significance to Tangata Whenua with the

surrounding area and whether the activity will result in severance or isolation

from the surrounding area, resulting in the loss of that value.

As a result of historic and ongoing consultation with iwi and hapū Contact is aware of a number of culturally significant sites in the wider Te Mihi / Wairākei area (see Figure 11.1). However, none of those sites will be affected by the proposed expansion of Te Mihi Power


Station. On that basis, it is considered that the proposed expansion of Te Mihi Power Station Site does not give rise to any issue in relation to the assessment criteria in Section 4e.4 of the Taupō District Plan.

Figure 11.1 – Sites of Cultural Significance

As noted in the previous section (in relation to archaeological effects), Contact has proposed consent conditions including a requirement to adhere to a Cultural / Archaeological Sites Protocol attached as Schedule 2 to the proposed consent conditions (this being the same document that forms part of the conditions relating to Consent RM070304 authorising the existing Te Mihi Power Station).


12. MANAGEMENT OF HAZARDOUS SUBSTANCES

As discussed in Appendix 3, the storage and use of hazardous substances on the Te Mihi Power Station Site is a permitted activity under Rule 4e.13.2 in the Taupō District Plan. Nevertheless, for the sake of completeness, the following provides an assessment of potential effects on the environment associated with the storage and use of hazardous substances associated with the proposed expansion of Te Mihi Power Station.

12.1 CURRENT USE OF HAZARDOUS SUBSTANCES

A range of hazardous substances is currently stored and used as part of the operation of Te Mihi Power Station including:

Mineral oils (including transformer insulating oil, turbine lubricating oil, and hydraulic oil);

Diesel;

Biocides;

Sulphuric Acid (used for reinjection acid dosing); and

Miscellaneous materials on a small scale or used or handled intermittently, such as cooling water sludges, organic solvents, de-greasers, paint, and compressed gases.

The Te Mihi Power Station already has environmental protection measures in place to ensure that all potentially hazardous substances are stored, transported and used in accordance with relevant legislation, standards, guidelines and best engineering and environmental practice.

12.2 HAZARDOUS SUBSTANCES REVIEW

As part of the wider GeoFuture Project (and specifically in relation to the applications that will be lodged with WRC at a later date), Contact engaged HD Geo to prepare a Hazardous Substances Review of all its activities on the Wairākei Field. The key conclusion in the Hazardous Substances Review relating to Te Mihi Power Station is as follows:

Overall, the plants are well run, neat and tidy, and have systems in place to minimise the likelihood of a release of hazards substances to the environment. Good practices, and in some instances, best industry practices, have been implemented at the sites, particularly at the Te Mihi and Poihipi Road sites.

HD Geo made a number of recommendations in relation to various minor matters whereby improvements could be made in relation to the management of hazardous substances. These recommendations related to the operation of the existing Te Mihi Power Station (rather than being relevant to the proposed expansion of Te Mihi Power Station). On that


basis, the Hazardous Substances Review has not been presented as an appendix to this AEE.

12.3 HAZARDOUS SUBSTANCES TO BE STORED AND USED

Options 1 (THI 1) and 2 (THI 2) associated with the expansion of Te Mihi Power Station will involve the same range of hazardous substances listed above associated with the operation of the existing Te Mihi Power Station, but in marginally greater quantities (in some instances).

Option 3 (THI 3) will involve the storage and use of pentane (being the working fluid associated with a Binary Plant). Pentane is a clear, colourless, flammable liquid with similar properties to petrol but with a lower HSNO classification (petrol is a 3.1A substance while pentane is a 3.1B substance). It is assumed (based on recent tender information of one of the suppliers for a similar plant), that the working fluid volume required by each of the four binary units is approximately 365m3, and an additional 175m3 per unit is held in each of four storage tanks. Accordingly, if four units are installed, a total of about 2,160 m3 of pentane would be held on Site THI B.

12.4 MAJOR HAZARD FACILITIES AND HAZARDOUS SUBSTANCES COMPLIANCE

Beyond the RMA consenting process, Option 3 (THI 3) (if selected) will be required to meet the requirements of the Health & Safety at Work (Hazardous Substances) Regulations 2017 (HS Regulations) and the Health & Safety at Work (Major Hazard Facilities) Regulations 2016 (MHF Regulations) for a new Binary Plant.

As Option 3 will store and use quantities of a Class 3.1B substance that exceed the MHF threshold listed in Schedule 2 of the MHF Regulations, Contact will need to comply with these regulations. As per Schedule 2 of the MHF Regulations, the quantity of up to 2,160 m3 of working fluid will make Site THI B an Upper Tier Major Hazard Facility.

WorkSafe implements and regulates the MHF regulations. WorkSafe has a dedicated team of inspectors who look after compliance with the MHF regulations. They will be involved from the designation of the proposed facility as an MHF, to the approval or rejection of the safety case. They also carry out regular inspections on operational sites to check ongoing compliance with the MHF regulations.

The MHF compliance programme involves:

Notification of the new MHF to WorkSafe

Submission of a Design Notice to WorkSafe at the concept design stage, which is required for all new MHF facilities (as opposed to an extension to an existing facility)

Preparation of a Safety Case, including implementation of control measures and an emergency plan


Approval of the Safety Case will be granted by WorkSafe providing it is satisfied that compliance with the regulations is met. After the Safety Case is submitted, WorkSafe will notify Contact when they start their assessment. During this process WorkSafe will issue lists of questions and will also organise site visits for Contact to demonstrate how they comply with the regulations as well as the content of the Safety Case.

As a result of the above process, all aspects associated with the storage and use of hazardous substances associated with the construction and operation of a Binary Plant (Option 3) will be adequately and thoroughly controlled by relevant legislation and regulations right from the design and construction stage of the expansion of Te Mihi Power Station to minimise any risk to human health and the environment.

12.5 MAJOR INCIDENT ANALYSIS

Contact engaged Safety Solutions to prepare a Major Incident Analysis in relation to the storage and use of pentane on Site THI B (see Appendix 11). The Executive Summary of that report is as follows:

This report presents the results of the consequence modelling12 completed for Major Incident Hazards (MIH)13 that may occur at Contact Energy’s proposed Te Mihi expansion Option 3 (THI_3). The results are presented as areas within which serious harm14 to persons or fatality may occur. This report does not assess the likelihood of an MIH occurring. This consequence modelling assumes there are no buildings or geographical features such as hills that reduce the impact of the event. This means that it is very conservative. The results presented in this report are the worst-case outcomes.

From hazard and risk assessments carried out at Contact’s Wairakei and Te Huka sites, which have similar processes and plant technology, three significant MIH consequence scenarios have been identified. These include:

a) an explosion of the cyclopentane storage tank (BLEVE),

b) fire from release of cyclopentane from the unit, and

c) explosion from release of cyclopentane from the unit.

The expected capacity and process conditions of the new plant have also been based on Contact’s existing or tendered binary plants. The results of the consequence modelling

12 Consequence modelling is a means of predicting the physical effects of an incident and its impact on people,

equipment, and the environment. The purpose of this report is to present the consequence analysis conducted to determine the extent of harm that may occur from a Major Incident (MI) at the new binary plant.

13 A Major Incident Hazard (MIH) is a hazard that has the potential to cause a Major Incident (MI). An MI is an uncontrolled event that exposes multiple persons to a serious risk to their health and safety arising from exposure to a harmful substance.

14 The criteria used for assessing consequences of the modelled incidents are based on New Zealand and international practices and regulations. Please refer to Section 5 of this report for the thresholds used for each level of concern.


are presented below in Table 1 as the distances from the source within which serious harm to persons may occur.

As with Contact’s existing binary plants, this facility will operate under the requirements of the Health and Safety at Work Act (Major Hazard Facilities) (MHF) Regulations 2016. This would require the implementation of protection systems to a level where it can be demonstrated that the risk has been eliminated, or failing that, minimised So Far As Is Reasonably Practicable (SFAIRP).

The results of this modelling show the largest area of impact is produced from the explosion of a cyclopentane storage tank, as shown in Figure 1 above. There is a 300m buffer between the serious harm contour (yellow) and current residential activities. For this reason, risk modelling would not be expected to show any effect on current residential activities. It is important to note that the land within the area of impact identified is either owned or ‘controlled’ by Contact via an encumbrance such that no new residential dwellings are permitted to be built and no activities of concern to Contact can


be performed within the area of impact identified, unless permitted by Contact. The plant will be located behind a hill with respect to neighbours located to the North-west. This is likely to further reduce the area of impact. Therefore, there is likely to be no effect on either current or potential future neighbouring residential activities even when assuming worst-case conditions.

The proposed plant for THI_3, will consist of up to four geothermal powered generation units, located on a footprint to the east of the existing Te Mihi Power Station. Power will be generated in each unit by using geothermal fluids to heat a working fluid such as cyclopentane, which is a flammable substance similar in characteristics to petrol. The cyclopentane boils, creating pressurised vapour, which is used to spin turbines and the associated generator. The exhaust is then cooled back to a liquid and returned to the start of the cycle in a closed system. Each of the four units will hold 365m3 of cyclopentane and 175m3 of storage each in four tanks.

The main hazards present at the new binary plant are associated with the use of cyclopentane. The MIH scenarios modelled investigate the extent of harm that may occur from a cyclopentane fire or explosion. Various release scenarios (e.g., release location and conditions) were considered.

Further sensitivity analyses were also conducted to consider any variability from the estimated values. Alternative working fluids such as n-pentane and isopentane, and increased storage capacity were modelled. The results indicate that n-pentane and isopentane produce less severe consequences than cyclopentane due to their material properties.

Increasing the storage tank capacity by 50% resulted in a 20% increase in potential area of injury or fatality. However, this increased area would not impact either current or any potential future neighbouring residential activities, for reasons explained above. The results of the sensitivity analysis are presented below in Table 2.15

15 Footnote 4 in Table 2: The dispersion of the n-pentane and isopentane vapour clouds was found to be 25%

less than that for cyclopentane. However, this is still sufficient to cover the area occupied by one unit such that the congested volume remains the same. Hence, the output of an n-pentane or isopentane VCE overpressure is only negligibly lower than that for cyclopentane. Please refer to Section 8 for detailed VCE modelling methodology.


In line with the approach taken by the BOI when granting resource consents in 2008 for the establishment of Te Mihi Power Station, Contact has proposed consent conditions which, upon the completion of detailed design of Stage 2 of Te Mihi Power Station, require a Hazardous Substances Risk Assessment (qualitative or quantitative) to be undertaken and an updated Emergency Management Plan for Te Mihi Power Station (covering Stages 1 and 2 of Te Mihi Power Station) (see Appendix 14). Beyond that, approval will be required from WorkSafe to ensure that Option 3 (if selected) achieves compliance with the MHF regulations.


13. CONTAMINATED SOILS, FAULT LINES AND HOT GROUND

13.1 CONTAMINATED SOILS

As noted in Section 4.1.6, a PSI has been undertaken which is presented in Appendix 12. The PSI concludes that the earthworks associated with the expansion of Te Mihi Power Station do not require a resource consent under the NES-CS.

Based on the above, it is concluded that there will be no risk to human health as a result of the earthworks associated with the expansion of Te Mihi Power Station.

13.2 FAULT LINES AND HOT GROUND HAZARD

As previously noted, there are a number of fault lines in the vicinity of Te Mihi Power Station and a substantial proportion of Site THI B is identified as a Hot Ground Hazard Area in the Taupō District Plan.

Contact has positioned the proposed activities associated with the expansion of Te Mihi Power Station to avoid the fault lines (being the fault lines identified in the Taupō District Plan and others identified more recently by GNS).

An assessment of the Hot Ground Hazard Area has been undertaken (see Appendix 4). It concludes that “there is no detectable near-surface geothermal activity” on Site THI B. Ground temperatures ranged from 10.5˚C and 13.3˚C. That does not pose any problem in relation to the construction of any of the proposed power station options on Site THI B. A consent condition has been proposed which requires further investigations of Site THI B prior to construction and confirmation that the design of any buildings and structures within the Hot Ground Hazard Area can avoid or mitigate any adverse geothermal effects.


14. AIR QUALITY EFFECTS

As previously noted, an application for an Air Discharge Permit associated with the operation of the expansion of Te Mihi Power Station will be lodged with WRC at a later date. Any Air Discharge Permit granted by WRC will include conditions which control the nature and extent of discharges to air. This will include conditions that ensure that:

Adverse effects on the health of people do not arise; and

There is no objectionable or offensive odour beyond the boundary of the Te Mihi Power Station Site.

The key aspect of air quality associated with the application to TDC for a Land Use Consent for the expansion of Te Mihi Power Station relates to the control of dust during construction activities. Rule 4b.1.19 in the Taupō District Plan requires:

“No dust or silt nuisance beyond the boundaries of the allotment (except internal allotment boundaries).”

A consent conditions has been proposed (see Appendix 14) which states:

“The consent holder shall ensure appropriate dust control methods are implemented so that no objectionable or offensive dust nuisance occurs beyond the boundaries of the site.”

The conditions also require the preparation of a Construction Management Plan which is to include measure to ensure compliance with the condition relating to the control of dust set out above.

As previously noted, the bulk earthworks associated with the creation of Site THI A were completed as part of the construction of Stage 1 of Te Mihi Power Station. Only minimal earthworks will occur on Site THI A associated with building foundations, services and the 220 kV underground section of transmission line linking the generation unit to the switchyard.

The significant distance between Site THI B and any neighbours will assist in terms of avoiding any dust nuisance. Dust will be controlled by a combination of measures including the following:

Using the existing sealed entrance as the point of entry to the site;

Provision of water carts or sprinklers (to be utilised, as required, for dust suppression during earthworks); and

Revegetating exposed areas as soon as practical.


15. EFFECTS ON TERRESTRIAL ECOLOGY AND THERMOTOLERANT VEGETATION

As described in Section 2.3, the terrestrial ecology of the area in which the Te Mihi Power Station is located is highly modified. The actual power station site, including Site THI A, is predominantly covered in hard stand (concrete and tar seal) or gravel (see the photo in Figure 1.3). Approximately two-thirds of Site THI B is gently rolling pastoral farmland while the balance is planted in production forestry (pinus radiata) (see Figures 1.4 and 1.5).

The wider area surrounding Te Mihi Power Station comprises farmland including some shelter belts of exotic tree species and the occasional self-sown native tree. The Wairākei Borefield land is generally covered with grass and scrubby vegetation. Sites THI A and THI B, on which the expansion of Te Mihi Power Station is proposed, along with the proposed access road to Site THI B and the transmission line to the switchyard, do not contain any significant indigenous vegetation or significant habitats of indigenous fauna.

There is no thermotolerant vegetation in the areas where development is proposed. The closest thermotolerant vegetation is in the Alum Lakes area which is about 85 m to the east of Site THI B. The physical works associated with the expansion of Te Mihi Power Station (on either Sites THI A or THI B) will not have any adverse effect on the Alum Lakes area which is identified in the Taupō District Plan as a SNA and in the Waikato Regional Plan as a SGF, and nor will there be any adverse effects on thermotolerant vegetation.

There is only one stream in the vicinity of the Te Mihi Power Station. Te Kiri o Hinekai Stream originates just south of the Te Mihi Power Station. It is a mostly dry ephemeral stream bed which remains in its natural state for about 600m heading east and picking up surface stormwater runoff along the way. It then passes through a culvert under a road at the western end of the WBF.

Te Kiri o Hinekai Stream is located south of Site THI B. Any earthworks on Site THI B will be at least 20 m away from the stream at its closest point. An Erosion and Sediment Control Plan (“ESCP”) will be prepared prior to the commencement of any earthworks to ensure that there will be no adverse effects on Te Kiri o Hinekai Stream. The ESCP will form part of the Construction Management Plan proposed in the conditions of consent (see Appendix 14).


16. POLICY AND PLANNING ASSESSMENT

The following policy and planning documents are relevant to the assessment of the Land Use Consent Application for the proposed expansion of Te Mihi Power Station:


National Policy Statement for Renewable Electricity Generation;







A detailed analysis of the relevant objectives and policies in the documents listed above is presented in Appendix 13. A summary of the findings of that analysis is presented as follows.

16.1 VISION AND STRATEGY FOR THE WAIKATO RIVER

The “vision” in the Vision and Strategy for the Waikato River focuses on restoring and protecting the health and wellbeing of the Waikato River. A series of more detailed provisions provide the means to realise that vision. As explained in Section 1.4 of the AEE, the expansion of Te Mihi Power Station is part a larger project being advanced by Contact referred to as “GeoFuture”. GeoFuture is about reconfiguring and reconsenting Contact’s activities on the Wairākei Field (forming part of the wider Wairākei-Tauhara Geothermal System) in order the achieve a more efficient utilisation of the geothermal resource for renewable electricity generation purposes and to reduce any adverse effects on the Waikato River. Specifically, GeoFuture (including the expansion of Te Mihi Power Station) will result in the following outcomes which are consistent with the Vision and Strategy: Cessation of discharges of Separated Geothermal Water (“SGW”) by Contact to the

Wairākei Stream and the Waikato River by 30 June 2026 at the latest; and

Cessation of the discharge of geothermal condensate to the Waikato River by 30 June 2031 at the latest (as part of shutting down the Wairākei A & B Power Stations).

The proposed expansion of Te Mihi Power Station will be undertaken in a manner that has no adverse effect on the Waikato River. The site is approximately 5 km to the west of the Waikato River. Earthworks will be managed to ensure that there is no sediment laden runoff of to surface waterbodies.


On the basis of the above, it is concluded that the proposed expansion of Te Mihi Power Station is consistent with the Vision and Strategy.

16.2 NATIONAL POLICY STATEMENT FOR RENEWABLE ELECTRICITY GENERATION

The National Policy Statement for Renewable Electricity Generation 2011 (“NPS-REG”) sets out an objective and policies to enable the sustainable management of renewable electricity generation under the RMA. The objective of the NPS-REG is:

To recognise the national significance of renewable electricity generation activities by providing for the development, operation, maintenance and upgrading of new and existing renewable electricity generation activities, such that the proportion of New Zealand’s electricity generated from renewable energy sources increases to a level that meets or exceeds the New Zealand Government’s national target for renewable electricity generation.

The proposed expansion of Te Mihi Power Station is entirely consistent with the NPS-REG. It will make a further contribution towards meeting the Government’s target of 90 percent of electricity generation being from renewable sources by 2025 (in an average hydrological year) providing this does not affect security of supply.

16.3 NATIONAL POLICY STATEMENT ON ELECTRICITY TRANSMISSION

The National Policy Statement on Electricity Transmission 2008 (“NPS-ET”) sets out the objectives and policies for managing the electricity transmission network under the RMA.

The objective of the NPS-ET is:

To recognise the national significance of the electricity transmission network by facilitating the operation, maintenance and upgrade of the existing transmission network and the establishment of new transmission resources to meet the needs of present and future generations, while:

• managing the adverse environmental effects of the network; and

• managing the adverse effects of other activities on the network.

The proposed short section of 220 kV transmission line associated with the expansion of Te Mihi Power Station is entirely consistent with the objective and policies in the NPS-ET set out above. The transmission line will enable electricity to be efficiently conveyed from the new generation unit(s) to the existing switchyard which is connected to the National Grid. Based on the conclusions reached in the Landscape and Visual Assessment (see Appendix 6), it will do so in a manner that does not give rise to any adverse effects on the amenity of the environment in which it is located or the wider area.


16.4 NATIONAL ENVIRONMENTAL STANDARD FOR CONTAMINANTS IN SOIL

The National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health 2011 (“NES-CS”) provides a nationally consistent set of planning controls and soil values to ensure that land that has been affected by contaminants is appropriately identified and assessed before any development occurs. Where necessary, the NES-CS provides guidance for remediation or containment of contaminants to make the land safe for human use.

The objective of the NES-CS it to ensure contaminated land is appropriately identified and assessed when soil disturbance and/or land development activities take place and, if necessary, remediated, or the contaminants contained, to make the land safe for human use.

The NES-CS has been addressed in Sections 4.1.6 and 13 of this AEE. Based on the analysis presented in Section 13, it is concluded that the proposed expansion of Te Mihi Power Station will be undertaken in a manner that is consistent with the intent of the NES-CS.

16.5 WAIKATO REGIONAL POLICY STATEMENT

The Waikato Regional Policy Statement (“RPS”) includes a wide range of objectives and policies that guide the management of natural and physical resources in the Waikato Region. The objectives and policies that are relevant to the proposed expansion of Te Mihi Power Station are presented under the following headings in the RPS:

Resource Use and Development;

Regionally Significant Industry;


Energy;

Ecosystem Services;

Tangata Whenua;

Sustainable and Efficient Use of Resources;

Air Quality;

Built Environment;

Geothermal Resources;

Historic and Cultural Heritage;

Biodiversity;

Amenity;

Natural Character;


Natural Hazards.

The analysis presented in Appendix 13 concludes that the proposed expansion of Te Mihi Power Station is consistent with the objectives and policies in the RPS under the headings listed above. This is largely due to the proposal being appropriately located on a Development Geothermal System, avoiding sensitive aspects of the environment, and ensuring that any adverse effects are appropriately avoided, remedied of mitigated.

16.6 WAIKATO REGIONAL PLAN

The Waikato Regional Plan (“WRP”) is not relevant to the assessment of an application for a Land Use Consent under the provisions of the Taupō District Plan and the NES-CS. The provisions of the WRP will be relevant to the applications that Contact lodges with WRC at a later date.

Appendix 13 briefly discusses one aspect of the WRP (in relation to the management of geothermal resources) to provide context for the application to TDC for an expansion of Te Mihi Power Station. The key aspect of the WRP is that the Wairākei-Tauhara Geothermal System is classified as a Development Geothermal System.

16.7 TAUPŌ DISTRICT PLAN

The Taupō District Council regulates the use of land by way of rules in the Taupō District Plan (“TDP”). The proposed expansion of the Te Mihi Power Station is mostly within the Rural Environment and partially within the Industrial Environment in the TDP.

16.7.1 Rural and Industrial Environments

The TDP recognises that electricity generation and transmission activities are a significant and important part of the Rural Environment in the Taupō District. There are at 11 geothermal power stations (and one more currently under construction) and at least 10 hydro-electric power stations in the Taupō District.

The objectives and policies seek to enable electricity generation (and transmission) activities in the Rural Environment while ensuring that any significant environmental effects of those activities are appropriately avoided, remedied or mitigated. Based on the conclusions reached in this AEE, the expansion of Te Mihi Power Station has been advanced in a manner that achieves those outcomes.

For the same reasons discussed in relation to the Rural Environment, the proposed expansion of Te Mihi Power Station is also consistent with the objectives and policies relating to the Industrial Environment.


16.7.2 Other Objective and Policies

There are a range of other objectives and policies in the TDP which are relevant to the proposed expansion of Te Mihi Power Station. The topics addressed in these provisions are:

Land Development;

Traffic;

Tangata Whenua Cultural Values;

Landscape Values;

Natural Values;

Natural Hazards;

Hazardous Substances;

Network Utilities;

Geothermal Activity.

The proposal is consistent with these objectives and policies largely due to it not being located in, or adversely affecting, any areas of recognised importance or particular value (e.g. SNAs or significant natural landscapes). In other respects, the proposal is consistent with the relevant objectives and policies on the basis that any adverse effects are avoided, remedied or mitigated (as discussed in the sections of this AEE dealing with actual or potential adverse effects on the environment).

16.8 NGĀTI TŪWHARETOA IWI ENVIRONMENTAL MANAGEMENT PLAN

The Ngāti Tūwharetoa Iwi Environmental Management Plan (“NTIEMP”) is a document that needs to be considered under section 104(1)(c) of the RMA. It sets out a range of provision seeking outcomes in relation to:

Kaitiakitanga;

Partnership; and

Ngā Taonga.

As discussed in Section 17, Contact has undertaken consultation (and will continue to do so) with a range of iwi and hapū groups in relation to GeoFuture, including the proposed expansion of Te Mihi Power Station. One of the purposes of that consultation is to ensure that activities are undertaken by Contact in a manner which, as much as possible, achieves the outcomes that the NTIEMP seeks.


16.9 PART 2 OF THE RMA

All of the matters specified in section 104 of the RMA to which the consent authority must ‘have regard to’ are subject to Part 2 of the RMA which sets out the purpose and principles of the Act.

16.9.1 Section 5 of the RMA – Purpose of the Act

The cornerstone of Part 2 is the Purpose of the RMA as set out in section 5(1), which is:

To promote the sustainable management of natural and physical resources.

Section 5(2) of the RMA defines sustainable management as:

Managing the use, development and protection of natural and physical resources in a way or at a rate which enables people and communities to provide for their social, economic, and cultural wellbeing and for their health and safety while-

(a) Sustaining the potential of natural and physical resources (excluding minerals) to meet the reasonably foreseeable needs of future generations; and

(b) Safeguarding the life-supporting capacity of air, water, soil and ecosystems; and

(c) Avoiding, remedying or mitigating any adverse effects of activities on the environment.

The overarching intention of the resource consent application process is to ensure that the proposed activities are consistent with the purpose of the RMA.

In terms of section 5 of the RMA, the proposed activities will enable people and communities to provide for their social, economic, and cultural well-being and for their health and safety by generation of electricity from a renewable source and the creation of employment and associated economic activity. The economic benefits of the proposed expansion of Te Mihi Power Station are discussed in Appendix 5.

Sustainable management enables the use and development of resources while ensuring that the circumstances in section 5(2)(a)-(c) are able to be satisfied.

In terms of the needs of future generations, the expansion of Te Mihi Power Station is intended to meet the increasing demand for electricity (generated from a renewable source) by present and future generations. Based on the conclusions reached in this AEE, the life supporting capacity of air, water, soil and ecosystems will be safeguarded, and any adverse effect on the environment will be no more than minor.

16.9.2 Section 6 of the RMA – Matters of National Importance

Section 6 of the RMA sets out the matters of national importance that must be recognised and provided for in managing the use, development and protection of natural and physical resources as follows:

(a) The preservation of the natural character of the coastal environment (including coastal marine area) wetlands and lakes and rivers and their margins and the


protection of them from inappropriate subdivision, use and development:

(b) The protection of outstanding natural features and landscapes from inappropriate subdivision, use and development:

(c) The protection of areas of significant indigenous vegetation and significant habitats of indigenous fauna:

(d) The maintenance and enhancement of public access to and along the coastal marine area, lakes and rivers:

(e) The relationship of Māori and their culture and traditions with their ancestral lands, water, waahi tapu, and other tāonga;

(f) The protection of historic heritage from inappropriate subdivision, use and development;

(g) The protection of protected customary rights;

(h) The management of significant risks from natural hazards

Most aspects of section 6 of the RMA are not relevant to the proposed expansion of Te Mihi Power Station.

In terms of section 6(a), there are no coastal environments, wetlands, lakes or rivers within the Land Use Consent Area.

In terms of section 6(b), the RPS and the TDP identify ‘outstanding natural features and landscapes’ but none of these are within proximity to the Te Mihi Power Station Site.

In terms of section 6(c), no areas of significant indigenous vegetation will be affected by the proposed expansion of Te Mihi Power Station.

In terms of section 6(d), there will be no impacts on public access to waterbodies as a result of the proposal.

In terms of sections 6(e), (f) and (g), Contact will continue to engage with Ngāti Tūwharetoa (and hapū groups) to ensure that these sections of the RMA are appropriately addressed in relation to the ongoing operation of the Wairākei Geothermal Power Scheme, including the proposed expansion of Te Mihi Power Station. Contact has proposed consent conditions including a requirement to adhere to a Cultural / Archaeological Sites Protocol attached as Schedule 2 to the proposed consent conditions (this being the same document that forms part of the conditions relating to Consent RM070304 authorising the existing Te Mihi Power Station) (see Appendix 14).

In terms of section 6(h), the location of the proposed activities has been selected to avoid fault lines. An assessment of the Hot Ground Hazard Area (relating to the eastern part of Site THI B) has been undertaken (see Appendix 4) and the activities can be designed to avoid any potential adverse effects arising.

Based on the above, the proposed expansion of Te Mihi Power Station is not contrary to any of the matters of national importance set out in section 6 of the RMA.


16.9.3 Section 7 of the RMA – Other Matters

Section 7 of the RMA sets out the matters that particular regard must be had to in managing the use, development and protection of natural and physical resources as follows:

(a) kaitiakitanga:

(aa) the ethic of stewardship:

(b) the efficient use and development of natural and physical resources:

(ba) the efficiency of the end use of energy:

(c) the maintenance and enhancement of amenity values:

(d) intrinsic values of ecosystems:

(e) [Repealed]

(f) maintenance and enhancement of the quality of the environment:

(g) any finite characteristics of natural and physical resources:

(h) the protection of the habitat of trout and salmon:

(i) the effects of climate change:

(j) the benefits to be derived from the use and development of renewable energy.

Most aspects of section 7 of the RMA are relevant to the current application by Contact.

The ability for tangata whenua to exercise kaitiakitanga in relation to the resources of the Te Mihi / Wairākei area will be part of the ongoing discussions that Contact is having with Ngāti Tūwharetoa and other iwi and hapū groups.

The matters listed in section 7 (aa), (b), (ba) and (g) form part of Contact’s proposed management of the ongoing operation of the Wairākei Geothermal Power Scheme, including the proposed expansion of Te Mihi Power Station. Contact seeks to manage resources in accordance with the ethic of stewardship. It is in Contact’s commercial interests to manage and use resources (particularly geothermal fluid and energy) in an efficient manner, all of which recognises the finite characteristics of natural and physical resources and the potential for unsustainable geothermal resource use if not managed and controlled appropriately. A key aspect of this is the location of geothermal power stations in close proximity to the hotter parts of the geothermal resource such as Te Mihi, maximising the efficiency and sustainable output of the Wairākei Geothermal Power Scheme.

Section 7(c) requires that regard be had to the maintenance and enhancement of amenity values. Amenity values are defined in section 2 of the RMA as being:

those natural or physical qualities and characteristics of an area that contribute to people’s appreciation of its pleasantness, aesthetic coherence, and cultural and recreational attributes.

The assessment of environmental effects has determined that any adverse effects on amenity values will be no more than minor. In this regard, the relevant noise limits


specified in the Taupō District Plan will be complied with and there will be no, or less than minor, landscape and visual effects (depended on which option is constructed).

In relation to section 7(d) and (f), Contact has proposed measures to ensure the intrinsic values of ecosystems are not compromised (largely by avoiding such areas), and its activities will likely result in an improvement to the quality of the environment as a result of helping to decarbonise the economy.

Finally, section 7(j) is particularly relevant to the current application. The proposed activities will enable the renewable generation of additional electricity equivalent to the demand of up to 70,000 households. The range of benefits associated with this level of renewable electricity generation are discussed in detail within the Economic Benefit Assessment (see Appendix 5).

16.9.4 Section 8 of the RMA – Treaty of Waitangi

Section 8 of the RMA states:

In achieving the purpose of this Act, all persons exercising functions and powers under it, in relation to managing the use, development, and protection of natural and physical resources, shall take into account the principles of the Treaty of Waitangi (Te Tiriti o Waitangi).

The requirement to take into account the principles of the Treaty of Waitangi is an obligation on those exercising functions and powers under the RMA, including in this case TDC making a decision on Contact’s Land Use Consent application.

Contact acknowledges the special status of tangata whenua and the relationship they have with their taonga tuku iho (inherited treasures). Contact also recognises that the Wairākei Geothermal Power Scheme is dependent on the use of resources that have spiritual and cultural significance to tangata whenua.

Contact continues to work with tangata whenua in a manner that is intended to be consistent with the principles of the Treaty of Waitangi. The particular steps that Contact has taken to work with Ngāti Tūwharetoa and other relevant hapū and iwi have been discussed in Section 17 of this AEE.


17. CONSULTATION AND ENGAGEMENT

The following sets out a summary of the consultation and engagement that has been undertaken by Contact, and the results of the same, prior to the lodgement of the Land Use Consent application for the expansion of Te Mihi Power Station (in Part A of this document). The consultation undertaken to date has been in relation to the wider GeoFuture project of which the expansion of Te Mihi Power Station is a key component. Contact will continue to consult with these parties as required, and as requested, throughout consenting process.

17.1 TAUPŌ DISTRICT COUNCIL

Meetings with TDC have been undertaken as follows:

A meeting was held with David Trewavas (Mayor), Gareth Green (CEO), and Scott Devonport (Consents and Regulatory Manager) on 13 March 2020. The purpose of the meeting was to introduce the GeoFuture project and discuss the consenting pathway. As discussed in Section 4.3 of this AEE, Contact is applying for the Land Use Consent for the expansion of Te Mihi Power Station as a standalone exercise ahead of the suite of resource consents that will be applied for from WRC at a later date relating to all aspects of the ongoing operation of the Wairākei Field. This approach has been adopted at the request of TDC (which occurred at the meeting on 13 March 2020) on the basis that the environmental issues associated with the expansion of Te Mihi Power Station within TDC’s jurisdiction are very limited in scope and magnitude. Furthermore, TDC saw no merit in being involved in a joint process that will be primarily focused on a much wider range of environmental issues beyond its jurisdiction that will be traversed in the context of the applications to WRC.

A meeting was held with Scott Devonport and Heather Williams on 13 November 2020 which focused on the environmental issues associated with the Land Use Consent application and provided a progress update.

Meetings were held with Heather Williams on 20 May 2021 and 22 July 2021 which focused on the environmental issues associated with the Land Use Consent application and processing timeframes and logistics.

17.2 WAIKATO REGIONAL COUNCIL

Various meetings have been held with WRC in relation to the wider GeoFuture project since early 2020. This has included meetings with Chris McLay, Brent Sinclair, Diane Palmer, Susanne O’Rourke, Hugh Keane, and Grant Eccles (Planning Consultant engaged by WRC to be the s.42A report author).

At the most recent meeting (on 30 June 2021), WRC confirmed that it had no objection with Contact’s proposed approach (based on a request by TDC as discussed above) whereby the Air Discharge Permit for the expansion of Te Mihi Power Station will be


applied for at a later date as part of the wider suite of applications for regional resource consents to authorise the ongoing operation of activities on the Wairākei Field.

17.3 TANGATA WHENUA

Consultation has been undertaken with a range of iwi and hapu groups as part of the wider GeoFuture project including:

Tūwharetoa Māori Trust Board

Ngā hapū o Wairākei, including members and representatives of:

o Oruanui Marae (Te Kapa o te Rangiita ki Oruanui)

o Maroanui Marae (Ngāti Rauhoto a Tia)

o Oruanui Marae (Te Kapa o te Rangiita ki Oruanui)

o Te Rangiita Marae (Ngāti Ruingarangi)

o Nukuhau Marae (Ngati Rauhoto, Ngati Te Urunga)

Ngā Kaihautū o Te Awa o Waikato Komiti

Wairākei Charitable Trust

Te Kotahitanga o Ngāti Tūwharetoa

Representatives of Ngāti Te Kohera and Ngāti Tutemohuta hapū

Ngati Tahu – Ngati Whaoa Runanga

Te Arawa River Iwi Trust

Discussions with these iwi and hapū groups have so far covered all components and potential effects associated with the GeoFuture applications, including the Land Use Consent application for the proposed expansion of Te Mihi Power Station. Contact has sought to provide an opportunity for attendees at meetings to ask questions or raise any issue or matter of concern. However, generally speaking, discussions have tended to focus on resource sustainability, river ecology and mahinga kai surveys, thermotolerant vegetation studies, engagement with hapū, sharing of economic benefits from development, and the approach to cultural impact assessments relating to the GeoFuture applications that will be lodged with WRC at a later date.

Contact remains mindful of the contents and recommendations in the Cultural Impact Assessment prepared by Gayle Leaf and Dr Charlotte Severne dated 14 November 2007 in relation to the Stage 1 of the Te Mihi Power Station development, and as far as possible incorporated them into the expansion proposal.

Active engagement on GeoFuture by Contact with tangata whenua remains ongoing.


17.4 TRANSPOWER NZ LIMITED

Consultation has been initiated with Transpower in relation to the proposed expansion of Te Mihi Power Station including the proposed 220 kV transmission line connecting into the existing switchyard (owned and operated by Transpower) located immediately north of Te Mihi Power Station. This has included a draft of this AEE being provided to Transpower.

Transpower has advised that its interest in the proposed expansion of Te Mihi Power Station is to ensure that the operation, maintenance, upgrading and development of the existing switchyard / substation and transmission lines (including support structures) is not compromised and that any works around these assets are carried out safely. In particular, Transpower seeks to ensure that:

Physical access to Transpower’s switchyard, transmission lines and support structures is maintained at all times;

All activities (including earthworks, mobile plant / machinery and people), buildings and structures comply with the safe separation distances set out in the New Zealand Code of Practice for Electrical Safe Distances (NZECP 34:2001) (“NZECP”); and

Dust and/or particulate matter, rubbish or any other material does not cause damage to, or accumulate on, transmission lines or support structures.

Contact will continue to engage with Transpower with a view to agreeing a set of consent conditions (a draft of which has been provided by Transpower) which appropriately address the issues listed above. It is anticipated that an updated set of proposed conditions (augmenting the conditions presented in Appendix 14) will be provided to TDC prior to the completion of the s.42A report.

17.5 DEPARTMENT OF CONSERVATION

The Contact GeoFuture project team and a team of officers from the Department of Conservation (“DOC”) established to engage on the GeoFuture project, have held regular monthly video conference briefings about GeoFuture since December 2020. The overarching purpose of these meetings is to keep DOC’s team and subject matter experts informed about the key components of the GeoFuture project, including the land use activities the subject of this application. Importantly, the meetings provide a regular opportunity for DOC to raise any issues or concerns it may have about the GeoFuture project, including the Land Use Consent application for the proposed expansion of Te Mihi Power Station.

No concerns about the proposed expansion of Te Mihi Power Station have been raised by the DOC during these meetings.


17.6 WAKA KOTAHI / NEW ZEALAND TRANSPORT AGENCY

Consultation was undertaken with Waka Kotahi / NZTA as part of the preparation of the Integrated Transportation Assessment presented in Appendix 9. It states:

NZTA were consulted in July 2020 regarding the expected construction traffic volumes. NZTA have confirmed that they do not require further consultation and that they are satisfied that no assessment of effects on their network is required.

17.7 NEIGHBOURS AND GENERAL PUBLIC

Consultation with neighbours and the general public has been undertaken as follows:

An invitation-only consultation meeting focusing on neighbours in the Te Mihi / Oruanui area (where neighbours could attend any time between 5pm and 6.30pm) was held at Te Mihi Power Station on 25 May 2021.

A Community Consultation Open Day for the general public (3.30pm to 6.30pm) was held at Wairakei Power Station on 1 June 2021.

Both of the above consultation events related to the wider GeoFuture Project including the proposed expansion of Te Mihi Power Station.

Noise was the main issue of concern raised by some of the neighbours in the Te Mihi / Oruanui area. Feedback was also provided by some of the neighbours in relation the quality and adequacy of the landscaping that was undertaken as part of Stage 1 of Te Mihi Power Station (it being acknowledged that it was difficult to get trees and shrubs to grow in the poor-quality soils and, at times, harsh climate associated with the Te Mihi / Oruanui area).

Attendees at the Community Consultation Open Day were few in number and attended mostly out of general interest, rather than having any particular concerns about what was proposed. The future development of the Karetoto well site (located adjacent to Wairākei Drive opposite the Wairākei International Golf Course) and any associated effects on the nearby tourism related businesses was a matter of particular interest, but not relevant to the current application for the proposed expansion of Te Mihi Power Station.


18. PROPOSED CONSENT CONDITIONS

As discussed in Section 1 of this AEE, Te Mihi Power Station operates in accordance with a

Land Use Consent (Consent RM070304) within the jurisdiction of TDC, and a suite of

associated resource consents within the jurisdiction of the WRC.

Consent RM070304 is subject to various conditions of consent. Contact’s objective is to

secure a Land Use Consent which authorises the proposed expansion of the Te Mihi

Power Station (i.e. all the options proposed) and making sure it dovetails with the

conditions of Consent RM070304. Contact does not seek to change any of the

substantive requirements of the existing conditions having been determined as

appropriate by a BOI.

Based on the above:

Contact has advanced the Land Use Consent application for the expansion of the Te Mihi Power Station in a manner that only relates to the aspects of the proposal that go beyond what is authorised by Consent RM070304;

To ensure consistency, Contact is proffering proposed consent conditions on the Land Use Consent for the expansion of the Te Mihi Power Station which are the same (at least in substance) to the existing conditions in Consent RM070304 as applicable (minor changes have been made to some conditions due to, for example, relevance and timeframes specified); and

Contact has included additional conditions on the Land Use Consent for the expansion of the Te Mihi Power Station only to the extent that they specifically relate to the activities authorised beyond the activities authorised under Consent RM070304.

In line with the above, a draft of the Land Use Consent for the expansion of the Te Mihi

Power Station including proposed consent conditions (as sought by Contact) is set out in

Appendix 14.

The conditions proffered by Contact are intended to address and control the nature and

magnitude of any actual or potential adverse effects on the environment associated with

the proposed expansion of the Te Mihi Power Station.


19. LAPSE PERIOD AND TERM OF CONSENT

19.1 LAPSE PERIOD

Contact seeks a lapse period of 10 years. This is both necessary and appropriate for the following reasons:

The timing of construction of the expansion of Te Mihi Power Station will be dependent on a number of factors including:

o The ongoing reliability and cost associated with the ongoing operation of the Wairākei A & B Power Stations;

o The demand for, and projected long-term price of, electricity in relation to the expected costs of constructing and operating the new power station unit; and

o The long ‘lead times’ associated with the design, procurement, supply of generation plant, and construction associated with the development of a geothermal power station.

19.2 TERM OF CONSENT

As is normal practice in relation to Land Use Consents (apart from those relating to temporary activities), no term of consent is proposed by Contact (i.e. an unlimited term of consent is sought).


20. NOTIFICATION OF THE APPLICATION

Section 95 of the RMA sets out a detailed set of considerations in relation to a decision by a territorial authority as to whether or not a resource consent application should be processed on a non-notified or notified basis (and, if the latter, whether limited or full notification is appropriate). One of the considerations is whether or not the applicant has requested the application be notified.

While this AEE concludes that there are no adverse effects on the environment that are more than minor, Contact considers it appropriate to allow interested and potentially affected parties the opportunity to have their say in relation to the proposed expansion of Te Mihi Power Station (beyond the consultation already undertaken as described in Section 16). Accordingly, Contact requests that TDC publicly notified the Land Use Consent Application (in Part A of this document) to provide the opportunity for interested and potentially affected parties to lodge submissions and have the ability to be heard at a hearing (if they wish to do so).


21. CONCLUSION

A Land Use Consent is required within TDC’s jurisdiction (as a Discretionary Activity) due to the proposed expansion of Te Mihi Power Station exceeding several performance standards in the Taupō District Plan.

The proposed expansion of the Te Mihi Power Station is part of a larger project being advanced by Contact referred to as “GeoFuture”. The GeoFuture project is about reconfiguring and reconsenting Contact’s activities on the Wairākei Field (forming part of the wider Wairākei-Tauhara Geothermal System) in order the achieve a more efficient utilisation of the geothermal resource for renewable electricity generation purposes and to reduce any adverse effects on the Waikato River. Resource consent applications will be lodged with Waikato Regional Council at a later date (anticipated to be at the end of 2021) for all activities on the Wairākei Field which require a resource consent under the Waikato Regional Plan.

An Assessment of Environmental Effects has been undertaken in relation to the Land Use Consent Application for the proposed expansion of Te Mihi Power Station. That assessment concludes that the proposal, as a key part of GeoFuture, will result in:

A net increase in electricity generation equivalent to the demand of up to 70,000 households with only a modest (around 2%) increase in geothermal fluid take;

Significant economic benefits on the local and regional economy including $520 million to $600 million in revenue terms during the construction phase;

A reduction in greenhouse gas emissions associated with a greater proportion of electricity being generated from a renewable source;

The cessation of separated geothermal water discharges to the Waikato River associated with Contact’s electricity generation activities;

The closure of the Wairākei A & B Power Stations resulting in the discontinuance of geothermal condensate being discharged to the Waikato River;

No, or less than minor, landscape and visual effects (depending on which option is constructed);

Compliance with the relevant noise limits specified in the Taupō District Plan;

Construction traffic being managed to ensure the safety and efficiency of the roading network is maintained;

No adverse effects on any recorded or known archaeological sites alongside a set of cultural / archaeological protocols in relation to any accidental discovery;

No adverse effects on identified culturally significant sites (none being located within the Land Use Consent Area);


The storage and use of hazardous substances in accordance with relevant legislation, regulations and environmental best practice to minimise any risk to human health and the environment;

No adverse effects in relation to contaminated soils (none being present or otherwise being appropriately managed if discovered during construction);

Fault lines avoided and any hot ground encountered being properly managed in relation to the construction of any of the proposed power station options on Site THI B;

Construction activities, including earthworks, being managed to avoid any dust or silt nuisance beyond the site; and

No adverse effects on terrestrial ecology, streams or thermotolerant vegetation.

On the basis of the above outcomes, the proposed expansion of Te Mihi Power Station is consistent with the relevant objectives and policies in the applicable policy and planning documents, including:


National Policy Statement for Renewable Electricity Generation 2011;







The proposal is also consistent with Part 2 (Purpose and Principles) of the RMA.

Contact has proffered a proposed set of consent conditions which are intended to address and control the nature and magnitude of any actual or potential adverse effects on the environment associated with the proposed expansion of the Te Mihi Power Station. The proposed conditions are based on, and most of them are the same or similar (at least in substance) to, the existing conditions in Consent RM070304 as applicable. Additional conditions have also been proffered that specifically relate to aspects of the proposed expansion of Te Mihi Power Station which are beyond the activities authorised under Consent RM070304.

Despite the absence, or minor nature, of any adverse effects on the environment, Contact has requested that TDC publicly notify the Land Use Consent Application for the


proposed expansion of Te Mihi Power Station to provide a formal opportunity for interested and potentially affected parties to lodge submissions and have the ability to be heard at a hearing (if they wish to do so).

1 APPENDIX 1

Records of Title and Survey Office Plan

2 APPENDIX 2

Plans of Proposed Power Station Options

3 APPENDIX 3

Taupo District Plan – Analysis of Rules and Performance Standards

4 APPENDIX 4

Hot Ground Assessment

5 APPENDIX 5

Economic Benefit Assessment

6 APPENDIX 6

Landscape and Visual Assessment

7 APPENDIX 7

Acoustical Assessment

8 APPENDIX 8

Independent Peer Review of Acoustical Assessment

9 APPENDIX 9

Integrated Transportation Assessment

10

APPENDIX 10

Archaeological Assessment

11

APPENDIX 11

Te Mihi Binary Plant Major Incident Analysis

12

APPENDIX 12

Preliminary Site Investigation

13

APPENDIX 13

Analysis of Policy and Planning Documents

14

APPENDIX 14

Draft Land Use Consent and Proposed Conditions

Report with Form 9 28.04

Documents

Transcript of Report with Form 9 28.04