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Name  Position  Company 

Mike Dworkin Vice‐President Development & Operations 

MEPAU 

Steve McCracken  Project Director ‐ Waitsia  MEPAU 

Kevin Davey Operations Manager – Perth Basin 

MEPAU 

Kevin Rollo Project Controls Manager ‐ Waitsia 

MEPAU 

Martin Heller Senior Advisor – HSE and Project Approvals, Corporate 

MEPAU 

Alex Mata  Operations Project Manager  MEPAU 

Colin Knox  Technical Safety Engineer  MEPAU 

Simon Elliott  Engineering Manager ‐ Waitsia  MEPAU 

Hannah Fletcher HSE Approvals and Compliance Coordinator ‐ Waitsia 

MEPAU 

Lara Centa  Senior Advisor –Environment   MEPAU 

Disclaimer:   

This document is protected by copyright, no part of this document may be reproduced or adapted without  the  consent of  the originator/company owner, all  rights are  reserved.  This document  is “uncontrolled when printed”, refer to electronic copy for up to date version. 

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TABLE OF CONTENTS 

1.0  PROJECT SUMMARY ............................................................................................................ 6 

1.1  Existing Approved Premises .............................................................................................. 6 

1.2  Proposed Works Approval and Licence Amendment ....................................................... 6 

   

   

   

   

1.3  Modification to Prescribed Premises Boundary ................................................................ 8 

   

   

   

   

3.0  PREMISES DETAILS AND ACTIVITIES OVERVIEW ................................................................. 14 

3.1  Premises Maps ................................................................................................................ 14 

3.2  Premises Legal Description .............................................................................................. 14 

3.3  Project Infrastructure ...................................................................................................... 17 

4.0  SENSITIVE RECEPTORS AND LAND USES ............................................................................. 19 

   

   

4.2  Ground Disturbance ........................................................................................................ 22 

4.3  EP Act Part IV Screening Assessment .............................................................................. 22 

5.0  DETAILS OF PROPOSED ACTIVITIES .................................................................................... 26 

5.1  Overview of Gas Processing Operations ......................................................................... 26 

5.2  Construction Works and Schedule .................................................................................. 27 

   

   

   

5.3  Commissioning ................................................................................................................ 33 

6.0  EMISSIONS, DISCHARGES AND WASTE ............................................................................... 35 

   

   

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6.2  Waste Storage and Disposal ............................................................................................ 42 

   

6.3  General Waste Management .......................................................................................... 42 

   

   

6.4  Emissions and Discharges Applicant Controls Summary ................................................. 44 

7.0  RISK ASSESSMENT AND APPLICANT CONTROLS ................................................................. 47 

8.0  OTHER APPROVALS AND CONSULTATION DOCUMENTATION ............................................ 54 

9.0  ADDITIONAL INFORMATION SUBMITTED .......................................................................... 56 

10.0  WORKS APPROVAL FEES .................................................................................................... 62 

11.0  REFERENCES ...................................................................................................................... 64 

 

LIST OF FIGURES

Figure 1‐1: Regional Location of the Prescribed Activity ..................................................................... 9 

Figure 2‐1: Status of L1 Production Licence ....................................................................................... 10 

Figure 5‐1: XPF Facility Layout (Pre‐Upgrade) .................................................................................... 29 

Figure 5‐2: Layout of Proposed XPF Facility Equipment Upgrades .................................................... 30 

Figure 5‐3: Evaporation Pond Civil Detail at Waitsia‐02 Wellsite ...................................................... 32 

Figure 6‐1: Noise Contour Plot based on measured noise levels and inclusion of the new compressor 

with silencer on exhaust..................................................................................................................... 38 

Figure 7‐1 Risk Management Process ISO 31000:2009 ...................................................................... 47 

Figure 7‐2: MEPAU’s Risk Matrix ........................................................................................................ 48 

Figure 10‐1: Licence Fee Calculation .................................................................................................. 62 

LIST OF TABLES

Table 4‐1: Environmental Values and Proximity to Prescribed Premises Boundary ......................... 19 

Table 2: Definitions of Commissioning Terms .................................................................................... 33 

Table 3: Emissions Sources used in the Air Assessment .................................................................... 36 

Table 6‐1: MEPAU Environmental Approvals/Monitoring associated with the WS1E Project .......... 44 

Table 7‐1: Construction Phase ERA .................................................................................................... 49 

Table 7‐2: Commissioning Phase ERA ................................................................................................ 50 

Table 7‐3: Operations ERA.................................................................................................................. 51 

Table 8‐1: Stakeholder Consultation Undertaken .............................................................................. 55 

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LIST OF ATTACHMENTS

Attachment 1A ‐ Proof of Occupier Status 

Attachment 1B ‐ ASIC Company Extract 

Attachment 2A ‐ Prescribed Premises Boundary 

Attachment 2B ‐ Landowners Adjacent to the Prescribed Premises Boundary 

Attachment 3A ‐ Layout of Key Project Infrastructure 

Attachment 6A – Emission and Discharge Points ‐ XPF 

Attachment 6B – Emission and Discharge Points – Waitsia‐02 wellsite evaporation pond 

Attachment 6C – Emission and Discharge Points – HPF evaporation ponds 

Attachment 7A – Sensitive Receptors and Land Uses 

Attachment 7B – Regional Location and Environmental Values 

Attachment 7C – Native Vegetation Clearing Permit Areas 

Attachment 8A – Environmental Commissioning Management Plan

Attachment 8B – Air Dispersion Modelling Report (Ramboll, 2019) 

Attachment 8C – Acoustic Assessment Report (Herring Storer, 2019) 

Attachment 8D – Process Flow Diagrams and Site Layout at XPF and Waitsia‐02 Wellhead 

Attachment 8E – Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

Attachment 9 – Capital Cost of Proposed Works (ex GST) 

 

   

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1.0 PROJECT SUMMARY 

1.1 Existing Approved Premises 

This Works Approval Application has been prepared for the Waitsia Stage 1 Expansion (WS1E) Project.  

An existing Licence (L7847/2003/7) exists for Category 10 activities (oil or gas production from wells) at the Xyris Gas Production Facility (XPF) and the Hovea Oil and Gas Production Facility (HPF).  This  Licence  was  amended  most  recently  on  6  March  2014  (issued  until  29  March 2022), over a prescribed premises boundary encompassing a large portion of Lots 3 and 4, on Plan 13178.  

The Licence approved a premises production/design capacity of no more than 500,000 tonnes per annum (tpa) of gas and oil production from wells.  

1.2 Proposed Works Approval and Licence Amendment 

Location and Summary of WS1E Project 

AWE operates facilities that produce hydrocarbons from the Waitsia gas field, located within the onshore North Perth Basin (the Shire of Irwin).   

The WS1E Project is located approximately 20 km southeast of Dongara and Port Denison and 350 km north of Perth.  The Project  is  located within  the  coastal  highlands of  the Mid West region  of Western  Australia  (WA) within  the  Lesueur  Sandplain  subregion  of  the Geraldton Sandplains  Bioregion  (Figure  1‐1).  The  facilities  and  pipeline  route  are  situated  within predominantly cleared agricultural land. 

The existing XPF is located on Pye Road, east of the Brand Highway, and the existing Waitsia‐02 (W‐02) wellsite  is  located approximately 500m north of the XPF. The HPF  is  located 5 km southwest of the XPF. 

Activities  associated  with  the WS1E  Project  that  relate  to  this Works  Approval  Application include: 

Plant equipment/infrastructure upgrades within the XPF 

Installation of a waterline  from the XPF Water Storage Tank to the Waitsia‐02 wellsite and  construction  of  an  evaporation  pond  at  the  Waitsia‐02  wellsite  for  storage  of produced formation water; and 

Continued PFW storage at the HPF evaporation ponds. 

The equipment and infrastructure upgrades at the XPF, will  increase the production capacity of the XPF plant from 10 Tera joules per day (TJ/d) of gas up to 30 TJ/d.  

The waterline, once installed, will run from the XPF to the W‐02 wellsite for transport of PFW with a low hydrocarbon content, for storage within an evaporation pond at the W‐02 wellsite. The  water‐line  will  be  comprised  of  HDPE  where  installed  below  ground  and  galvanised carbon steel where installed above ground.  

The increased production capacity of the XPF will enable continued production from the two existing wells, Senecio‐03 and Waitsia‐01, and allows the Waitsia‐02 well to produce into the XPF plant. As the wells are depleted, additional wells may be tie‐in to the Waitsia Gas Flowline to  produce  into  the  XPF.  It  is  noted  that  30  TJ/day  is  calculated  to  be  the  equivalent  to 224,769 tonnes of gas per year. 

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There are currently no plans to undertake any new works within the HPF, which is located on Pye Road a few kilometres southwest of the XPF.  The HPF is in a care and maintenance phase following  cessation  of  operations  in  2010,  and  PFW  is  currently  trucked  from  the  XPF  for storage within  the  HPF  evaporation  ponds.  The  evaporation  ponds may  also  receive water recovered from well intervention activities from time to time as per current practice. 

The  activities  at  HPF  are  managed  under  the  Waitsia  Gas  Project  Commissioning  and Operations  Environment  Plan  (MEPAU,  2019).  No  changes  to  any  infrastructure  at  HFP  is proposed, and PFW storage within the HPF evaporation ponds will continue with the upgrade at the XPF.  

Commissioning works at the XPF will be undertaken prior to first gas from late Q2 2020. 

Supporting Information (this document) 

This  Supporting  Information  Document  has  been  prepared  as  supplementary  to  the Works Approval Application for the WS1E Project (further describes the activities in Section 1.2.1).   

The Works Approval Application is for changes to the nature and location of the emissions and discharges under Category 10 of the existing Licence, but no new Works Approval Category is being applied for. 

A Licence Amendment application will be made for the WS1E Project following completion of commissioning activities. 

WS1E Project – Out of Scope 

The WS1E Project also comprises construction of a new 3.7km gas export pipeline  from the XPF  (Waitsia  Gas  Export  Pipeline)  to  allow  gas  production  from  the  XPF  to  the  Dampier  to Bunbury  Natural  Gas  Pipeline  (DBNGP).  The  pipeline  route  and  associated  fenced  tie‐in compound  adjacent  to  the  DBNGP  (Waitsia  Gas  Export  Compound)  are  out  of  scope,  but shown in Figure 1‐1 for reference. 

Environment  Plans  for  assessment  by  the  Department  of  Mines,  Industry  Regulation  and Safety  (DMIRS) are being submitted under  the Petroleum and Geothermal Energy Resources Act 1967 and Petroleum Pipelines Act 1969, and cover the following activities: 

Construction of  the underground gas pipeline and  tie‐in works at  the XPF and WaitsiaGas Export Compound;

Piping to connect the Waitsia‐02 well to the existing Waitsia Gas Flowline; and

Construction of the Waitsia Gas Export Compound.

The below ground pipeline is also subject to a Pipeline Licence application to be assessed by DMIRS  (see  Table  6‐1).  A  temporary  contained  ablutions  block  will  be  hired  for  the construction phase to accommodate the increased site personnel. 

The Perth Basin Facilities Environment Plan [MEPAU, 2019] covers the existing gas gathering system, which  includes the Senecio‐03 and Waitsia‐01 wellsites  (the current producing wells for the XPF), and their connecting flowlines from the Northern Hub (refer Figure 1‐1). 

Construction Schedule 

The construction and  installation works  for  the WS1E Project will  commence at  the start of 2020, with new equipment and  infrastructure at  the XPF scheduled to be  installed once the XPF is shut down from 1 January 2020. 

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Related  facility  and  piping  works  (including  construction  of  the  evaporation  pond  at  the Waitsia‐02 wellsite) will also be undertaken from January 2020. 

Construction is on the critical path, as commencement of operations (first gas) will occur from July 2020, following a short period of commissioning to achieving steady state operations. 

1.3 Modification to Prescribed Premises Boundary 

The  current  prescribed  premises  boundary,  as  approved  in  L7847/2003/7,  encompasses  a large portion of Lots 3 and 4, on Plan 13178.  The boundary has been reduced to more clearly denote where the WS1E Project applicable under Part V of the Environmental Protection Act 1986 will be undertaken, as well as continuing to incorporate the HPF.  

Attachment 2A below shows the reduced prescribed premises boundary, which encompasses the XPF, W‐02 wellsite, and the HFP.  These features are connected by the existing XAGGS line between  the  XPF  and  HPF,  however  this  is  an  isolated  retired/redundant  line  (the  HPF operations are in Care and Maintenance). 

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Figure 1‐1: Regional Location of the Prescribed Activity 

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3.0 PREMISES DETAILS AND ACTIVITIES OVERVIEW 

3.1 Premises Maps  

As  described  in  Section  1.3,  the  current  prescribed  premises  boundary  is  reduced  to  only cover  the  locations  and  activities  relevant  to  this  Works  Approval  Application  (and  future Licence Amendment) for the WS1E Project.  

The location of the ‘Prescribed Premises Boundary’ is in relation to the XPF, W‐02 wellsite and the HPF, as shown in Attachment 2A. 

3.2 Premises Legal Description 

The  XPF  is  located  on  Lot  4,  and  the  boundary  of  Lot  3,  on  Plan  13178.  Lot  4  is  held  by Whitmarsh  (Revive Nominees Pty Ltd) and Lot 3  is held by S.Micke  (Wongulla Park Pty Ltd). The Waitsia‐02 wellsite is located on Lot M357, which is the Irwin Park Farm owned by AWE.  

Irwin  Park  Farm  is  freehold  owned  by  AWE  (WA)  Investment  Company  Pty  Ltd,  which  is  a related body corporate of AWE Perth Pty Ltd. 

Landowner  access  agreements  are  in  place  for  the WS1E  Project,  with  ground  disturbance activities  to  occur  across  predominantly  cleared  agricultural  farmland  (freehold  land),   

 

  

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Attachment 2A ‐ Prescribed Premises Boundary 

XYRISPRODUCTION

FACILITY

HOVEAPRODUCTION

FACILITY

2

1. CO-ORDINATES TO GDA94 / MGA50.

LEGEND

3

6

7

8911

31

10

32

36

37

38

3029

28

2726

252322 24

2021

1716

15 14

13

12

1

33

435

345

WAITSIA-02WELLSITE

PYE ROAD

NOTES

PREMISE BOUNDARY

ROAD BOUNDARY

COMMON ROAD/LOT BOUNDARY

LOT BOUNDARY

EASEMENT BOUNDARY

18

19

LOT 4 ONP013178

LOT 3 ONP013178

LOT M357 ONP002993

LOT M357 ONP002993

LOT 3 ONP013178

LOT 4 ONP013178

LOT 4 ONP013178

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Attachment 2B ‐ Landowners Adjacent to the Prescribed Premises Boundary 

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3.3 Project Infrastructure 

The  key  infrastructure  and  equipment  that  are  part  of  this  Works  Approval  Application  is summarised below. 

This Works Approval Application is for emissions and discharges associated with: 

Plant equipment/infrastructure upgrades within the XPF

Installation of a waterline  from the XPF Water Storage Tank to  the Waitsia‐02 wellsiteand  construction  of  an  evaporation  pond  at  the  Waitsia‐02  wellsite  for  storage  ofproduced formation water; and

Continued PFW storage at the HPF evaporation ponds.

The location of key infrastructure associated with this Works Approval Application is depicted in Attachment 3A ‘Layout of Key Project Infrastructure’. 

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Attachment 3A – Layout of Key Project Infrastructure 

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4.0 SENSITIVE RECEPTORS AND LAND USES 

The location of sensitive values within the Regional area surrounding the prescribed premises are shown in Figure 1‐1.  The topography is relatively flat land.  

Residential Properties and Local Industries 

The nearest residential cluster is the Irwin townsite located approximately 9 km north of the XPF. The Dongara and Port Denison townsites are located approximately 20 km southeast of the XPF. 

Local  industries  within  close  proximity  includes  the Mondarra  Gas  Storage  Facility,  located approximately 3 km east of  the XPF, and  the Patience Sand Quarry  located approximately 1 km south of the XPF. 

Residential  properties  are  located  within  a  few  kilometres  of  the  XPF,  and  have  been identified as the nearest sensitive land uses/receptors2: 

House R2*/ Residence A#: located approximately 3.5km south west of XPF;

House R1* / Residence B#: located approximately 3.8km north east of XPF; and

House R4*: located approximately 4.5km north west of XPF.

These  properties  were  included  within  the  Air  Dispersion  Modelling  Assessment  Report *(Ramboll,  2019)  and  the Acoustic Assessment  #  (Herring  Storer,  2019)  (see Attachment 8A and Attachment 8B). 

The  location of  these  residential properties and  local  industry are  shown on Attachment 7A ‘Sensitive Receptors and Land Uses’. 

Conservation Significant Areas 

The  prescribed  premises  boundary  is  not  located within  any  conservation  significant  areas. The proximity of the prescribed premises boundary to environmental values is shown in Table 4‐1.  

Table 4-1: Environmental Values and Proximity to Prescribed Premises Boundary 

Environmental Sensitivity and Distance from the Prescribed Premises Boundary3 

Description of the Environmental Value 

Conservation Areas / Biological Features 

Ejarno Spring (riparian vegetation) 

~ 440 m southeast 

The Spring is located on freehold land and is comprised of a relatively large area of intact native vegetation (surrounding riparian vegetation). 

No impacts to this value are expected to occur associated with activities within the prescribed premises boundary. 

Nature Reserves (DBCA)  ~ 3.5 km south 

~ 12 km west 

~ 24km northeast 

Yardanogo Nature Reserve 

Beekeepers Nature Reserve 

Dongara Nature Reserve 

2 Distance to the nearest sensitive land uses (that is, a residence or other land use which may be affected by an emission 

or discharge associated with the proposed activities) – DWER Application Form 3 Measured from the XPF 

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Environmental Sensitivity and Distance from the Prescribed Premises Boundary3 

Description of the Environmental Value 

Conservation Areas / Biological Features 

Environmentally Sensitive Area 

~ 3 km southeast  Unspecified 

Soil and Landform  Within/adjacent to premises boundary 

Premises boundary is within previously disturbed agricultural land (cropping, sheep and cattle farming.) 

Surrounding native vegetation (excluding Ejarno Spring) has been degraded by grazing and introduced mammals are known to occur within the region. 

Geotechnical and soil assessment conducted within proximity of the premises boundary verified that the soils area comprised almost entirely of quartz sand (Blacktop, 2017).  

Geology  Within/adjacent to premises boundary 

The premises boundary is located within the Perth Basin which is described as a large, onshore and offshore immature to frontier petroleum basin on the southwest Australian passive margin, containing about 15km of predominantly siliciclastic marine and nonmarine sedimentary rocks. The premises boundary is located within the Yarragadee Bedrock geology unit which is described as fine‐ to coarse‐grained sandstone with thin shale interbeds. 

Groundwater  Within/adjacent to premises boundary 

The groundwater aquifer consists mainly of quartz sands, calcareous sands and limestone in the Tamala Limestone. The groundwater level is close to the surface in the south and in the centre but may be as much as 60 m below the surface, below the crests of the Tamala Limestone dunes along the coast.  

Areas of the Waitsia field with depths to groundwater of less than 20 m include areas west of the Gingin Scarp and in the northeast corner. The Waitsia‐02 monitoring bore indicates that standing water levels are approximately 8.425 m (MEPAU, 2018).  

The standing water level at the Hovea water supply bore is known to be 48.9 m (MEPAU, 2018). 

MEPAU maintains water quality results from its regular monitoring program which includes monitoring bores within the premises boundary. This program has not identified any instances of groundwater contamination that can be attributed to MEPAU’s activities. 

Specified Ecosystems 

Groundwater Dependent Ecosystem (GDE) 

~ 440 m southeast 

The closest expression of surface water is associated with Ejarno Spring, which is also a GDE (shallow expression of groundwater). 

The Ejarno Spring area is mapped as being underlain by the Guildford Formation; this suggests that the 

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Environmental Sensitivity and Distance from the Prescribed Premises Boundary3 

Description of the Environmental Value 

Conservation Areas / Biological Features 

spring discharges into a system that may be perched, like those described west of Eneabba (Kern, 1997). Such a perched system would not be significantly impacted by small changes in groundwater levels in the Yarragadee Aquifer. 

No impacts to this value are expected to occur associated from activities within the prescribed premises boundary. 

Waterbodies  ~4 km north  The next closest water body is the Irwin River some distance north of the premises boundary.  The Irwin River is adjacent to the Allanooka Groundwater Protection Area which extends further to the north of the region. 

Other Relevant Environment Features 

Cultural Heritage  Within/adjacent to premises boundary 

No known Aboriginal heritage sites occur within the premises boundary. 

AWE has commissioned a number of Archaeological and Anthropological surveys and assessments on the potential Aboriginal heritage significance of the areas with the Perth Basin Region (JCHMC, 2015; REO, 2015; TRC 2017). 

The Aboriginal Heritage Survey (REO, 2015) involving the Amangu and Widi Mob groups identified that Ejarno Spring is a place of importance and significance (although not listed). 

A heritage survey was undertaken on 2 October 2019 for the WS1E Project with Traditional Owners, an archaeologist and an anthropologist (report pending). 

European Heritage  ~3 km  The closest heritage site is the Munderra Farmhouse, and is listed as Category 3 on the Municipal Heritage List. 

Economic  Adjacent land  The land adjacent to the premises boundary is agriculturally dominated, with extensive oil and gas development (see 4.1.1). The surrounding region is sparsely populated with limited settlement, transport and communications infrastructure. 

Other economic activities in the greater Dongara region include primary industries such as agriculture and fisheries, and broad hectare cropping and grazing activities. Beekeeping, tourism and wildflower picking are other activities undertaken in the adjacent area. 

The  location  of  these  sensitive  land  uses/receptors  in  relation  to  the  prescribed  premises boundary is shown on Attachment 7B ‘Regional Location and Environmental Values’.   

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4.2 Ground Disturbance 

Ground disturbance work will be carried out within the XPF plant to install foundations for the new gas compressor (10m x 10m x 1m deep) and, install a bund for a methanol storage tank (10m x 7m x 1m deep).  

Ground disturbance work at the Waitsia‐02 wellsite includes construction of the evaporation pond  for  storage of produced  formation water. Other ground disturbance work adjacent  to the Waitsia‐02 wellsite  is  related  to pipeline construction works,  and  is  captured within  the DMIRS Environment Plans. 

The majority of proposed ground disturbance activities are located in existing hardstand areas or located with agricultural land that is currently used for farming. These disturbance activities will  require a  small  area of native vegetation  to be cleared associated with  the Waitsia Gas Flowline  and  the Waitsia Gas  Export  Pipeline  route.  These  activities  are  covered under  two exiting  native  vegetation  clearing  permits  (NVCP  CPS  6875/1  and  CPS  6938/1)  –  shown  in Attachment 7C ‘Native Vegetation Clearing Permit Areas’. 

4.3 EP Act Part IV Screening Assessment 

The WS1E Project activities covered under this Work Approval application will result in limited ground disturbance, the majority of which are limited to existing hardstands and agricultural properties. There will no vegetation clearing required outside of areas where Clearing Permits do not already exist. MEPAU has determined  that  this activity  can be managed without  the requirement for additional approval under the EP Act part IV as it is not within: 

500  m  of  Environmentally  Sensitive  Area  (including  World  Heritage  Properties,  BushForever  sites,  Threatened  Ecological  Communities,  defined wetlands,  areas  containingrare flora, areas covered by an Environmental Protection Policy);

500  m  of  a  declared/proposed  State  Conservation  Estate,  including  National  Park,Nature Reserve, Conservation Park, or State Forest and Timber Reserves;

A Public Drinking Water Source Area.; or

2 km of a declared occupied town site.

In addition to this, the activity is: 

Not a hydraulic fracturing exploration and development activity;

Not within the Strategic Assessment for the Perth Peel Region and potentially in conflictwith the outcomes of the Strategic Assessment; or

Not  previously  or  currently  subject  to  formal  assessment  by  the  EnvironmentalProtection Authority.

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Attachment 7A ‐ Sensitive Receptors and Land Uses 

 

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Attachment 7B – Regional Location and Environmental Values 

 

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Attachment 7C – Native Vegetation Clearing Permit Areas 

 

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5.0 DETAILS OF PROPOSED ACTIVITIES 

This Works Approval Application is associated with the construction and commissioning of the WS1E Project. A Licence Amendment application will be made for the WS1E Project following completion  of  commissioning  activities,  and  after  compliance  with  all  conditions  of  the granted Works Approval. 

The  WS1E  Project  includes  activities  within  the  prescribed  premises  boundary,  with  the prescribed activities comprising: 

Plant equipment/infrastructure upgrades within the XPF;  

Installation of a waterline  from the XPF Water Storage Tank to  the Waitsia‐02 wellsite and  construction  of  an  evaporation  pond  at  the  Waitsia‐02  wellsite  for  storage  of produced formation water; and 

Continued  produced  formation  water  (PFW)  storage  at  the  HPF  evaporation  ponds (6.3.2). 

5.1 Overview of Gas Processing Operations 

The  current  gas  production  facility  process  at  Xyris  comprises  reservoir  fluids  from  the Senecio‐03  and  Waitsia‐01  wells  (refer  Figure  1‐1)  treated  with  chemicals  from  dedicated chemical injection packages located in the well site compounds. The reservoir fluids are then transported via  flowlines to the Northern Hub, and from the Northern Hub, the Waitsia Gas Flowline transports the reservoir fluids to the XPF.  

The WS1E  Project will  tie  in  an  additional well  at Waitsia‐02  into  the Waitsia Gas  Flowline, which will transport reservoir fluids from the well site to the XPF. As per the Senecio‐03 and Waitsia‐01 wells, there will be dedicated chemical  injection packages at the wellsite to treat the Waitsia‐02 reservoir fluids. 

Once at  the XPF, a  two‐phase production separator  (upgraded as part of  the WS1E Project) separates  the  reservoir  fluids  into  liquid  and  gas  streams.  The  liquid  stream  (water  and condensate) is stored in the Liquid Stock Tank, where residence time allows for separation of water and hydrocarbon condensate.  

Currently,  condensate  is  transported  from  the XPF  to  the Dongara Production Facility  (DPF) and  loaded  into  the DPF condensate storage  tanks via  the Condensate Loading System. The condensate  is stored at DPF until export arrangements are made (covered under a separate DWER Licence ).  

The separated PFW is transferred to a new Water Storage Tank which will provide additional hold‐up/storage. A new Produced Water Disposal Pump will be provided to discharge the PFW to  the newly  constructed evaporation pond at  the Waitsia‐02 wellsite  compound  via  a new buried HDPE line. 

The XPF liquids system is also configured for manual load‐out of PFW via road tankers, where excess volumes of PFW can subsequently be discharged into the evaporation pond or turkey’s nest  at  HPF  (Section  3.3).  If  required,  PFW  can  also  be  transported  to  the Water  handling System at the DPF. 

The gas stream is conditioned on site at XPF and either exported as sales gas or will be used as fuel gas for the gas engine driven electrical generator and new compressor package. The new compressor package  is a gas engine driven reciprocating gas compressor package which will be installed to compress the export gas to a suitable pressure for delivery into the DBNGP via 

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a  new  14”  export  pipeline.  A  new  dedicated  vent  line  will  be  provided  to  depressurise separate sections of the facility, but is only required for shut down purposes, with no venting required during normal facility operation.  

Process  Flow  Diagrams  (PFDs)  and  Site  Layout  for  the  WS1E  Project  are  provided  in Attachment 8D (XPF and Waitsia‐02). 

5.2 Construction Works and Schedule 

Construction  activities  are  scheduled  to  commence  in  Q1  2020,  with  commissioning  is expected from May 2020. Based upon estimated work schedules, this work  is planned to be completed in Q2, with operations reading for first gas from Q3 2020. 

Activities  will  be  predominantly  undertaken  during  daylight  hours,  with  limited  24‐hour operations required. 

XPF Equipment/Infrastructure Upgrades  

Upgrades to existing equipment and  installation of new infrastructure  is required within the XPF to enable increased production capacity. All activities associated with upgrades to the XPF will be undertaken within the existing fenced area that borders the XPF.  

Prior to conducting this activity, existing equipment, piping and process tanks will be emptied and purged with nitrogen to ensure no hydrocarbon inventory is on‐site during these upgrade activities4.  

Within  the  XPF,  the  types  of  activities  to  be  undertaken  include  (but  are  not  limited  to), upgrades to the existing:  

Inlet slugcatcher vessel; 

Mercury Removal Unit (MRU); 

Fuel gas system; 

Gas  conditioning  system,  including  the  gas/gas  exchanger  and  low  temperature separator; 

Export metering system; 

Instrument air system; and 

Control and communications networks. 

In addition to these upgrades, the following new equipment will be installed:  

Water  storage  tank  and  water  transfer  pumps,  to  cater  for  the  increased  water production; and 

Methanol storage tank, to cater for the increased flow conditions; and 

Gas export compressor package.  

Additional activities will be undertaken, which are  covered under  the Facilities Construction Environment Plan submitted to DMIRS: 

Replacement of existing equipment (such as pneumatic controls), 

Replacement of above‐ground piping; 

4 This activity will be undertaken in accordance with the Perth Basin Facilities Environment Plan (DMIRS assessed) 

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Relocation  of  equipment  (such  as  the moisture  analyser  sample  point  and metering); and 

All electrical and instrumentation works associated with plant upgrade activities. 

Equipment  that  is  redundant  or has  been decommissioned during  the XPF upgrade may be removed offsite and disposed at an appropriately licenced facility. The type of equipment may include:  

Liquid collection boot; 

Liquid knock‐out pot (part of the previous gas/gas exchanger draining); 

Cool Energy research project facility; 

Inlet gas compressor package (redundant); 

XAGGS pipeline riser which is disconnected and isolated – noting the retired pipeline is filled with inhibited water; 

Buried HDPE piping; and 

Refrigerated water chiller package. 

An overview of key infrastructure and equipment associated with the XPF upgrade activities is included in Figure 5‐1 and Figure 5‐2. 

Civil works to be undertaken within the XPF  include concrete foundations to be  installed for the new methanol tank and export compressor, but other than this work, only minor ground disturbance will be required within the XPF (and already cleared hardstand area).  

A temporary diesel tank (in the order of 2 m3 capacity) will be located on‐site to supply fuel to vehicles, equipment and machinery during construction. 

 

 

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Figure 5‐1: XPF Facility Layout (Pre‐Upgrade) 

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Figure 5‐2: Layout of Proposed XPF Facility Equipment Upgrades 

 

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Evaporation Pond Construction at Waitsia‐02 Wellsite 

A new evaporation pond will be constructed at the Waitsia‐02 wellsite to store and evaporate the additional PFW associated with the increased XPF capacity.  

The  existing  drill  sump  pond  within  the  Waitsia‐02  wellsite  was  originally  proposed  to  be utilised as an evaporation pond for PFW volumes produced from the XPF. However the sump pond  was  not  considered  large  enough  and  it  may  not  have  been  possible  to  modify  the existing pond in time to meet the requirements of the first gas date.  

The  new  evaporation  pond  will  be  constructed  just  to  the  north  of  the  existing  pond, extending just outside the boundary of the cleared hardstand area of the Waitsia‐02 wellsite. As described in Section 4.2, the area is previously disturbed by the wellsite hardstand area and surrounding agricultural farming. The chosen area for the evaporation pond is located within agricultural land, this area was used for the flare pit during the well testing program. The flare pit has been removed and the area has been levelled and it has some re‐growth of non‐native vegetation.  

The dimensions of the new evaporation pond will be 50m x 50m (maximum width and length), and  up  to  2m  in  depth,  with  a  1.5mm High‐density  polyethylene  (HDPE)  liner  (refer  Figure 5‐3). This evaporation pond will only be required to operate for a few years until the Waitsia Stage 2 Project  is completed (currently under separate Part  IV EP Act assessment), when all produced formation water will then be discharged to the Waitsia Stage 2 plant for processing. Construction of this pond will comprise the following works:  

Civil earthworks associated with pond wall and base construction, and 

Installation of a new pond liner that is suitable for storing and evaporating of PFW.  

The  engineering  design will  be  in  accordance with  the Department  of Water  (DoW)  ‘Water Quality  Protection  Note  26  ‐  Liners  for  containing  pollutants,  using  synthetic  membranes’ (DoW, 2013)  in  regards to  the appropriate  liner  thickness  for  low hazard waste/longer‐term containment facilities.  

The sub‐grade will be prepared to ensure that all surfaces are be finished smooth and free of all debris  which may damage the pond liner. Jointing of liners and testing will be carried out strictly  in  accordance  with  the  manufacturer's  written  instructions.  The  volumes  of  PFW produced are likely to be greater than the capacity of the new evaporation pond, with excess volumes of PFW to be continued to be trucked from the XPF to the HPF evaporation ponds. It is estimated that approximately 50% of the PFW may be trucked to the HPF (mostly during the winter months), as per current practice.  

 

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Figure 5-3: Evaporation Pond Civil Detail at Waitsia-02 Wellsite

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Waterline from XPF to Waitsia‐02 Wellsite 

The  produced  water  pipe  (the  waterline)  will  be  installed  from  the  Water  Storage  Tank (containing PFW) at the XPF to the evaporation pond located at the Waitsia‐02 wellsite. The pipe will  be  fabricated  of  HDPE where  installed  below  ground  and  galvanised  carbon  steel where  installed  above  ground  (i.e.  along  the  Waitsia‐02  above  ground  piping).  The  above ground section will also be installed above ground on concrete pipe‐supports. 

The  pipe  integrity  will  be  tested  during  commissioning  and  at  regular  intervals  during operations. 

5.3 Commissioning 

Following completion of construction activities, commissioning activities will commence over a period of six weeks. The  following  facilities and  locations will be subject  to commissioning activities (an Environmental Commissioning Management Plan is provided in Attachment 8A): 

All new facilities, flowlines and pipelines including: 

Waitsia‐02 wellhead facility, above ground flowline and tie‐in compound; 

Waitsia Gas Export Pipeline and Pig Receiver Compound; 

The modified Xyris Production Facility; and 

The new Waitsia‐02 evaporation pond. 

As applicable, commissioning activities will include: 

Handover from the construction contractors to the commissioning team 

Pre‐commissioning of all aspects of the works; 

First  introduction of gas from the reservoirs through to the  isolation valve to the AGIG DBNGP Metering Compound at the battery limit of the Waitsia Export Pipeline; and 

Gas  commissioning  of  all  aspects  of  the  works  including  testing  and  tuning  of  the system. 

Once  commissioning  activities  are  complete,  the  facility will  be  handed  over  to  operations. The handover will comprise operator training and first start‐up and first commercial gas flows. 

The following definitions around commissioning are provided in Table 2 and below. 

Table 2: Definitions of Commissioning Terms

Term  Definition 

Commissioning  Unless specified otherwise, the term Commissioning shall generally refer to the entire commissioning works inclusive of Pre‐Commissioning and Gas Commissioning. 

Pre‐Commissioning  Energisation, pressurisation (non‐hydrocarbon fluids), functional testing and final inspection of equipment, instrumentation and control systems as far as practicable, such that the Facility is ready for the introduction of hydrocarbons. 

Gas Commissioning  All works required to progress the facility from the end of Pre‐Commissioning to the final handover to the Company’s Operations inclusive of the first introduction of hydrocarbon gas and liquids, first start‐up, commencement of commercial gas deliveries, tuning, and performance testing. 

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 Pre‐commissioning will include the following activities: 

• Functional testing of all manual and actuated valves through full extent of travel, using all functions; 

• Testing of actuated valve functions under nitrogen; 

• Commissioning of power supplies, battery chargers and batteries; 

• Calibration of all instrumentation; 

• Earthing compliance checks; 

• Hazardous area checks; 

• Cathodic Protection checks (temporary may need to be engaged to cover from completion of pipeline installation up until commissioning of permanent Cathodic Protection system); 

• Low pressure air  leak  testing of  facility piping, valve seats of  critical valves and pressure equipment; 

• Cold loop testing of all circuits; 

• Energising all circuits; 

• Functional testing of equipment; 

• Hot loop checks; 

• Motor bump checks; 

• Functionality checks on all control room equipment and field equipment; 

• Dry calibration of all instruments; 

• Final blow through of the facility pipework, including the vent system; 

• Punch listing; 

• Final alignments on the Compressor; and 

• All  other  pre‐commissioning  checks  required  to  be  carried  out  on  other  equipment necessary to enable the introduction of gas and initial pressurisation. 

Commissioning activities include but are not limited to: 

• Purge of air from all process pipework and the introduction of a nitrogen blanket; 

• Initial  pressurisation  of  all  process  and  utility  pipework  up  to  full  available  service pressure, in a progressive manner with repeated leak checks; 

• Wet  calibration  of  the  fuel  gas  system  and  verification  of  the  required  fuel  gas  process conditions; 

• Start‐up of the compressor package and commissioning of the compressor in accordance with approved procedures; and 

• Tuning of all control loops and modes to ensure stable system operation in all modes. 

• Re‐commissioning  of  all  existing  equipment  (electrical  generators,  air  compressors, loadout pumps and loadout hoses, etc). 

 

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6.0 EMISSIONS, DISCHARGES AND WASTE 

Potential Emissions and Discharges 

This  section  describes  the  potential  sources  of  emissions  and  discharges  that may  result  from activities associated with this Works Approval application (and future Licence Amendment). 

While there is the potential for minor dust and noise emissions during construction activities and commissioning (such as from operating vehicles and machinery and testing of the newly installed plant  equipment),  the  greatest  potential  for  atmospheric  air  and  noise  emissions  within  the premises  boundary  will  be  from  operations  following  the  upgrade  of  equipment  and infrastructure at the XPF. No flaring will be undertaken. 

Atmospheric emissions (gas and particulate) and noise emissions will occur from various section of the XPF during operations. An Air Dispersion Modelling Assessment Report was undertaken by Ramboll  Australia  Pty  Ltd  (Ramboll,  July  2019)  and  an  Acoustic  Assessment  was  modelled  by Herring Storer Acoustics (Herring Storer, July 2019). 

These  assessment  reports  are  described  in  the  sections  below,  with  applicant  controls  and suggested monitoring further described in 7.0. 

The emission and discharge point sources relevant to this Works Approval application are shown in Attachment 6A, 6B and 6C ‘Emission and Discharge Points’ depicting the plant and equipment at the XPF, the evaporation pond at the Waitsia‐02 wellsite and the HFP (fugitive air emissions). 

Atmospheric Emissions 

Dust 

Fugitive dust is likely to occur from vehicle and machinery movements, and dust emissions from exposed ground surfaces (particularly during the construction phase).  

The Air  Dispersion Modelling Assessment  Report  undertaken  by  Ramboll  (2019)  is  provided  in Attachment  8B.  The  Report  notes  that  sources  of  dust  are  difficult  to  quantify  accurately  and therefore  model.  Given  the  small  scale  of  the  activities  to  be  undertaken  with  the  premises boundary,  and  over  a  short  construction  period  of  approximately  6  months,  incidental  dust generation is considered negligible for causing off‐site impacts. Ramboll (2019) advised that dust is best addressed through a monitoring/management program.  

Gas/Particulate Emissions 

Air  emissions  will  be  associated  from  the  increased  plant  capacity  at  the  XPF.  The  following activities were identified during the Environmental Risk Assessment (ERA) (Section 7.0) as having the potential to result in air emissions: 

• Vehicle and machinery use; and 

• Equipment and generator use (including commissioning). 

The Air Dispersion Modelling Assessment Report undertaken by Ramboll  (2019).  This Report  is provided in Attachment 8B. Ramboll undertook air dispersion modelling to assess the potential air quality impacts of atmospheric emissions from the proposed expansion of the XPF, comparing the  ground  level  concentrations  (GLCs)  predicted  at  sensitive  receptor  locations  against  the relevant ambient air quality criteria. 

As  noted  in  the  Ramboll  Air  Report,  other  emission  sources  that  are  significant  in  the  region include  the Mondarra Gas Storage Facility and a nearby  sand mining operation  (Patience Sand 

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Quarry).  The  sensitive  receptors  assessed  in  the  Report  are  three  residential  properties, described in Section 4.1.1, located between 4.5km and 3.5km from the XPF (see Attachment 7A). 

The sources of atmospheric emissions identified by MEPAU for assessment in the Ramboll (2019) Report comprised the following (see also Table 3): 

Gas compressor engine and gas engine alternator; 

Liquid storage venting; 

Manual plant vents (maintenance only); 

Process water ponds at HPF ‐ evaporation and turkeys nest (fugitive emissions5); and 

Vehicular combustion sources. 

The sources of potential atmospheric emissions, the expected volume and frequency, location of potential  receptors  and  proposed  applicant  control  measures  to  minimise  emissions  and environmental impacts, are summarised in the Environmental Risk Assessment (ERA) in 7.0.  

Table 3: Emissions Sources used in the Air Assessment

Emission Source 

Gas Engine Generator (*A) 

Export Gas Compressor Engine (*B) (note 4) 

Gas Breakout Tank (*C) (note 3) 

Liquids Storage Tanks (*D & *E) 

(note 2) 

Plant Vent (*F)    (note 1) 

Total Quantity  1  1  1  1  2 

Quantity Operating  1  1  1  1  2 

Capacity (kw)  100   750   N/A  N/A  N/A 

Stack Height (m)  2  5  8  8  5 

Stack Internal Diameter (m)  0.114  0.179  0.29  0.146  0.2* 

Exit Velocity (m/s)  9.6  24.5  0.09  0.01  33 

Mass Rate (kg/hr)  417  2651  24  0.7  5200 

Mass Rate (kg/hr) HP  N/A  N/A  N/A  N/A  N/A 

Mass Rate (kg/hr) LP  N/A  N/A  N/A  N/A  N/A 

Temperature (oC)  300‐400  300‐400  23  20‐30  30 to ‐5  

Concentrations                

NOx 

Refer to Air Modelling Report / Engine Technical Datasheet 

N/A  N/A  N/A 

CO  N/A  N/A  N/A 

PM2.5  N/A  N/A  N/A 

PM10  N/A  N/A  N/A 

SO2  N/A  N/A  N/A 

H2S  <2ppm  <2ppm  <2ppm  <2ppm  <2ppm 

BTEX  <0.05% mol  <0.05% mol  2.5% mol  2.5% mol  0.05% mol 

Hg  <1ug/m3  <1ug/m3  <1ug/m3  <1ug/m3  <1ug/m3 

Table Notes: 

*  A,  B,  C,  D,  E,  F  are  shown  on  Attachment  6A  ‘Emission  and  Discharge  Points  –  Xyris  Production  Facility’. 1. Plant vents are only used during plant maintenance when the plant needs to be depressurised, or during compressor shutdowns. Gas rate is based on 9000 kPag upstream pressure and 12mm orifice. Vent height assumed to be 5m above grade.  *  Vent  diameter  has  increased  to  DN200  and  vent  exit  velocity  has  reduced  accordingly  (from  the  assessment undertaken by Ramboll, 2019). 

5 The HPF ponds can contain trace amounts of hydrocarbon and were included as fugitive air emissions sources. 

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2. Liquid storage tank vent rate is based on liquid discharge rate into the tank (from H&MB stream 180) as it is assumed that entrained gas flashes off in gas breakout tank. There is no additional emissions from the Produced Water Tank as it receives stabilised liquid from the Liquids Storage Tank. 3. Process data obtained from 25 TJ/d H&MB stream 181. Gas density is 1.1 kg/m3 and MW = 27.6 4. Compressor and Gas Engine Alternator  (GEA) engine exhaust gas  rate  is based on stoichiometric  combustion of  fuel gas,  fuel  gas  use  is  33  Sm3/h  (23.7  kg/h)  for  the  generator  (Cummings  CG6L‐8G1)  and  210  Sm3/h  (150  kg/h)  for  the compressor (Cat 3512). Calculation assumes 9.5 m3 of air (density = 1.25 kg/m3) for each m3 of gas (density 0.75 kg/m3) for full combustion. 

 

Ramboll  (2019) determined  that predicted GLCs are well  below  the  corresponding ambient air quality and workplace exposure standard criteria at  the  receptor  locations  (background annual average PM2.5  concentrations over‐factored  in  the model). When  considered without potential background  concentrations  of  pollutants,  short  term  impacts  from  NO2  was  identified  as  the main pollutant of potential concern  from the XPF, although predicted concentrations were still well below the nominated guideline (National Environment Protection Measures (NEPM)). 

Noise Emissions 

Noise  levels  will  increase  with  the  additional  plant  components  at  the  XPF.  The  following activities were  identified during the ERA (Section 7.0) as having the potential  to result  in noise emissions: 

• Vehicle, machinery use; and 

• Equipment and generator use (including commissioning). 

The Acoustic Assessment Report undertaken by Herring Storer (2019) is provided in Attachment 8C. The purpose of the acoustic assessment was to quantify the existing operational noise levels from the XPF facility (prior to the upgrade) and use noise modelling to predict cumulative noise levels following the inclusion of the proposed gas export compressor to enable noise levels at the nearest noise sensitive premises to be assessed. 

The sensitive receptors assessed in the Report are two residential properties, and are described in Section 4.1.1, located between 3.8km and 3.5km from the XPF (see Attachment 7A). 

By measuring the existing operational noise  levels at the XPF, Herring Storer developed a plant model  from  the  actual  noise  levels  to  predict  the  future  noise  levels  from  introducing  the compressor  into  the  facility. Noise  levels were modelled  the noise  levels using SoundPlan, and the results indicate that the highest calculated noise level at the 2 sensitive noise premises is 15 dB LA10.  

This  is  below  the  maximum  allowable  noise  level  of  35  dB  LA10,  which  determines  that  the proposed  upgrades  at  the  XPF  comply  with  the  criteria  stipulated  in  the  Environmental Protection (Noise) Regulations 1997 ‐ for all hours of operations during operations (Figure 6‐1). 

The proposed compressor is a CAT G3512B Gas Engine with an Ariel compressor unit fitted. The engine  is  not  enclosed;  however  the  exhaust  system  has  a  “Hospital  Pack”  silencer  fitted reducing the noise  level  to 75 dB(A) at 1 metre. The compressor engineering specifications are provided in the Herring Storer (2019) Noise Report (Appendix C of Attachment 6C). 

Subsequent  to  the  noise  modelling,  mufflers  have  been  installed  on  the  methanol  pump  air discharge  nozzles  to  reduce  noise  levels within  the  XPF  and  the  Joule‐Thompson  valve  on  the Low  Temperature  Separator  will  be  replaced  by  a  low  noise  valve  as  part  of  the  Project. Therefore, the main source of noise will be the new gas compressor. 

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The sources of potential noise emissions, the expected volume and frequency, location of potential receptors and proposed applicant control measures to minimise emissions and environmental impacts, are summarised in the ERA in 7.0.  

 

Figure 6-1: Noise Contour Plot based on measured noise levels and inclusion of the new

compressor with silencer on exhaust 

 

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Attachment 6A ‐ Emission and Discharge Points – Xyris Production Facility 

 

 

 

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Attachment 6B ‐ Emission and Discharge Points – Waitsia‐02 Wellhead Site 

 

 

 

 

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Attachment 6C ‐ Emission and Discharge Points – Hovea Production Facility 

 

 

 

 

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6.2 Waste Storage and Disposal 

Stormwater Containment 

There is the potential for stormwater to come into contact with small spills of hydrocarbons or chemicals with the XPF or Waitsia‐02 wellsite, resulting in contaminated stormwater. There is no change to the current stormwater handling management at the XPF or at the Waitsia‐02 wellsite (and the same process is followed at other MEPAU operating sites).   

All  process  equipment  and  tanks  that  may  contain  hydrocarbon  liquids  or  chemicals  are located  within  concrete  bunds.  The  bunds  are  designed  to  contain  liquid  spills  from  the equipment  to  allow  them  to  be  cleaned  before  they  can  cause  overflow  and  possible contamination  of  the  surrounding  hardstand.  The  bunds  are  also  designed  to  retain  the stormwater  that  falls  on  the  bunded  areas  as  this  water  may  be  contaminated  by  small volumes of oil or chemicals in the bunds 

The existing and new concrete bunds at XPF are shown in Attachment 8D (dwg XYR‐EXP‐DX‐001). 

The existing bunds  for  the Pig Receiver,  the Gas Engine Alternator  (GEA)/ Engine Alternator (DEA) (generators) and the bunds for the Liquid Storage Tanks and the Tanker Offloading Area all  have  external  sumps  that  are  drained  regularly  using  the  vacuum  trailer.  The  two  new bunds that will be constructed for the methanol tank and gas compressor will also have sumps (see Attachment 6A). 

All the other bunds (i.e. mostly gas systems with small volumes of liquids) have manual valves (normally closed), that allow draining the stormwater to grade once  it  is confirmed that  it  is clean  water.  If  the  water  is  contaminated,  these  bunds  will  be  emptied  using  the  vacuum trailer.  

At the Waitsia‐02 wellsite a concrete bund will be provided for the chemical storage tanks and injection pumps. This bund is provided with a sump to collect any spills or stormwater and it will be emptied regularly using the vacuum trailer. This system will have the same design and features  as  the  existing  systems  at  the Waitsia‐01  and  Senecio‐03 wellsites.  The Waitsia‐01 wellsite  layout  drawing  (dwg WAT‐DX‐002  in  Attachment  8D)  shows  the  existing  bund  and sump at this wellsite, and the Waitsia‐02 wellsite  is provided with the same bund and sump system.  

Contaminated  water  that  is  removed  with  the  vacuum  trailer  is  transported  to  DPF  and discharged into the Water Treatment System where the oil and water are allowed to separate, the  clean water  is  injected  into  a water  disposal well,  and  the  oil  is  transferred  to  the DPF condensate tanks.  

6.3 General Waste Management 

Waste generated during the activities within the premises boundary  includes hazardous and non‐hazardous wastes, such as putrescible food waste and process equipment waste. 

In accordance with MEPAU’s Health, Safety and Environment Management System, a Waste Management Plan (WMP) (PB‐HSE‐PLN‐001) has been prepared and provides an overview of the strategy, methods and controls implemented by MEPAU to manage waste.  

MEPAU will continue to implement its Waste Management Plan which specifically requires: 

Waste storage is available to enable hydrocarbon contaminated to be segregated from general waste; 

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Waste with  the potential  to be wind‐blown will be  stored  in a manner  to avoid  faunascavenging and windblown litter;

Controlled waste to be handled and transported from site by a licensed contractor, and

A waste inventory to be maintained.

A review of all incidents at MEPAU facilities over the past three years did not identify incidents associated with the generation and management of waste that caused impacts to protected fauna species. 

Produced Formation Water 

As described in Section 5.0, a waterline will be installed from the XPF Produced Water Tank to transport  PFW  for  storage  within  the  evaporation  pond  at  the  Waitsia‐02  wellsite.  The waterline will be comprised of both HDPE and carbon steel (below ground and above ground respectively). Pressure testing will be carried out on the water pipe during commissioning to confirm its integrity.  

The  new  evaporation  pond  will  be  constructed  with  a  HDPE  liner  of  a  minimum  1.5  mm thickness,  as  per  the DoW Water Quality  Protection Note 26  (DoW, 2013)  for  lined  storage compounds for long‐term containment of non‐hazardous materials. The evaporation pond will store  the  PFW  so  that  evaporation  occurs  over  time,  and  there  is  no  additional  water treatment proposed.  

The  maximum  capacity  of  the  Waitsia‐02  evaporation  pond  will  be  5,000m3,  based  on  a maximum design of 50m x 50m x 2m depth (allowing a maximum water level of 1.5m). As per the  existing  HPF  evaporation  ponds,  the  pond  capacity  has  been  designed  to  maintain  a freeboard of at least 0.5m. The evaporation ponds are visually inspected regularly to confirm the  integrity  of  the  liner  and  the  water  level  (depth  markers  are  installed),  to  ensure  the freeboard is maintained at all times as well as noting the presence of any fauna. Fauna egress mats are provided at the existing HPF ponds and will be provided at the Waitsia‐02 pond. 

In addition to the visual monitoring of the ponds, an existing water bore located downstream of  the  Waitsia‐02  wellsite  will  be  utilised  as  a  monitoring  bore  to  confirm  that  the  liner integrity is maintained and no PFW (hydrocarbons) are discharged to the environment though the liner (the existing groundwater monitoring program is undertaken in accordance with the Perth Basin Surveillance Sampling Program [PB‐HSE‐PRO‐119]). 

The  total  volume  of  PFW  to  be  produced  at  XPF  is  expected  to  be  8000  litres/day. Approximately 50% of this water to be discharged to the Waitsia‐02 evaporation pond and the balance  trucked to the HPF ponds as per current practice  (one truck every 4 days), which  is below the storage capacity of the containment infrastructure. Pond aeration will be provided as part of the pond design to enhance evaporation efficiency and reduce odour produced by bacteria in the water.  

Additionally, in the case of a very high rainfall period that results in high levels in the ponds, it is  possible  to  transport  PFW  from  the  Waitsia‐02  and  the  HPF  ponds  to  the  DPF  Water Treatment System or the Eremia‐4 disposal well which are approved for disposal.  

Based on the hydrocarbon characteristics and the residence time provided for evaporation, it is expected that the hydrocarbon will be less than 100ppm volume by the time it  is pumped from  the  Produced Water  Tank  to  the Waitsia‐02  evaporation  pond.  The  HPF  evaporation ponds have been operating  for approximately  three years and have not detected significant layers of hydrocarbons on the surface of the ponds. The Waitsia‐02 monitoring bore (located 

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~90 m south of the Waitsia‐02 exploration wellhead) indicates that standing water levels are approximately 8.425 m  (MEPAU,  2018). Ongoing groundwater monitoring has not  identified any instances of groundwater contamination that can be attributed to MEPAU’s activities. 

Existing HPF Evaporation Ponds 

Two water storage ponds are used within the existing HPF, an evaporation pond and a turkeys nest  (see Attachment 6C).  The  liquid  stored within  the HFP evaporation ponds and  turkey’s nest  is  mostly  PFW  (with  some  water  from  well  intervention  activities).  PFW  inputs  and evaporation, results in a pond capacity that maintains a freeboard of 0.5m.  

These facilities are will continue to store PFW as part of the existing Licence. 

6.4 Emissions and Discharges Applicant Controls Summary 

An  ERA  was  undertaken  by  AWE  which  is  detailed  in  Section  7.0  and  which  describes  the applicant controls for emissions and discharges. 

The  source  of  potential  emissions  and  discharges  assessed  in  Section  7.0  includes  the following activities: 

The operation of vehicles and machinery; 

Stormwater design and management within the XPF; 

Evaporation pond construction and produced formation water storage; 

Commissioning of the upgraded equipment and infrastructure within the XPF; 

Separation and processing of gas for export; 

Operation  of  the  gas  compressor, Gas  Engine Alternator  (GEA),  and  vents  at  the  XPF; and 

Operation of the generator, methanol injection pump, and separator at the XPF. 

MEPAU also has approvals under other legislation to manage and monitor emissions and discharges from the proposed activities within the premises boundary. These approvals and monitoring are described in Table 6‐1 below.  

The Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan is provided in Attachment 8E. 

 

Table 6-1: MEPAU Environmental Approvals/Monitoring associated with the WS1E Project

Approval Name  Approval Details 

DWER Water Licences: 

Dongara Production Facility ‐ GWL161951(5) 

Woodada Gas Field ‐ GWL155753(7) 

Hovea Production Facility ‐ GWL161322(5) 

Hovea Production Facility ‐ GWL151360(7) 

Waitsia Gas Field ‐ GWL173435(7) – includes Waitsia‐02 

Waitsia‐03 ‐ GWL183759(1) 

Corybas‐02 ‐ GWL176604(1) 

Groundwater abstraction is an approved activity under these existing water licences.  

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Approval Name  Approval Details 

Irwin‐01 ‐ GWL180269(1) 

Yardarino‐06 ‐ GWL179574(1) 

Eremia‐04 ‐ GWL179075(1) (to be renewed) 

Groundwater Monitoring Program 

Perth Basin Surveillance Sampling Program [PB‐HSE‐PRO‐119] 

This groundwater monitoring program details the frequency of, and the water quality parameters, required to be monitored across MEPAU’s Perth Basin facilities. The Program provides a water quality baseline, as well as a mechanism for identifying where water quality impacts may arise from specified activities to be developed and implemented. 

By conducting routine sampling, MEPAU can understand pre‐spill water quality baseline to support response decisions and support response termination. Specifically, MEPAU have a monitoring bore located downstream of the Waitsia‐02 well that is used to monitor groundwater quality.  

DMIRS Dangerous Goods Licence (DGL) 

DGL DGS016892 ‐ expires 30/12/2021 (DGL Site name is HPF but also encompasses XPF) 

A renewal to the existing DGL will be prepared prior to storage of the increased volumes of dangerous goods. 

DMIRS Environment Plan 

Onshore North Perth Basin Well Intervention Activities Environment Plan (HSE‐E‐075) 

This EP:  

Plug and abandonment of the Xyris‐01 well 

Removal of drill cuttings and fluids from the Waitsia‐02 sump pond and existing liner 

DMIRS Environment Plan 

Perth Basin Facilities Environment Plan (PB‐HSE‐PLN‐004) 

Extraction of water for construction purposes 

Depressurisation of the existing Waitsia Gas Flowline 

Removal of hydrocarbon inventory from the XPF 

Commissioning and operation of the XPF following construction 

Note: This updated EP is pending DMIRS acceptance 

DMIRS Environment Plan – submitted 

Waitsia Stage 1 Expansion Project: Facilities Construction Environment Plan [P‐WGP1‐018] 

XPF upgrade 

Piping construction (installation and tie‐in of Waitsia‐02 flowline) 

Construction of an evaporation pond at the Waitsia‐02 wellsite 

Construction of a fenced compound, and 

Supporting activities (construction/permanent offices) 

Note: This EP has been submitted to DMIRS and is pending acceptance 

DMIRS Environment Plan – in preparation 

Waitsia Stage 1 Expansion Project: Waitsia Gas Export Pipeline Construction Environment Plan [P‐WGP1‐019] 

 

Civil works 

Pipeline construction and installation 

Hydrotesting, and •  Installation of other below‐ground services within the 

same pipeline trench (i.e. fibre‐optic cable, instrument 

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Approval Name  Approval Details 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan [P‐WGP1‐020] – Attachment 8E 

air‐line, and produced water‐line) 

Note: This EP and the Construction Oil Spill Contingency Plan have not yet been submitted to DMIRS  

DMIRS Pipeline Licence Application – in preparation 

Waitsia Export Pipeline Licence 

Pipeline route ~3.7km from the XPF to the Waitsia Gas Export Compound (adjacent to the DBNGP) 

Note: The Application is pending re‐submission to DMIRS  

Shire of Irwin – if required 

Building Licence under the Building Act 2011 

Health Act 1911 approvals 

No Shire approvals are currently identified, but will continue to be assessed through the planning stages of the Project.  

The Shire of Irwin has advised that no planning approval is required under the Planning and Development Act 1995. 

 

 

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7.0 RISK ASSESSMENT AND APPLICANT CONTROLS 

A  qualitative  Environmental  Risk  Assessment  (ERA)  has  been  undertaken  to  assess  the emissions and discharges as described in Section 6.0. MEPAU’s ERA approach aligns with the processes outlined in ISO 31000:2009 Risk Management ‐ Principles and Guidelines (Standards Australia/Standards  New  Zealand  2009)  and  Handbook  203:2012  Managing  Environment‐related Risk (Standards Australia/Standards New Zealand 2012) (Figure 7‐1). 

 

Figure 7‐1 Risk Management Process ISO 31000:2009 

MEPAU conducted an ERA workshop in accordance with MEPAU’s Perth Basin Operations Risk Matrix [HSE‐SC‐306] which has been provided in Figure 7‐2.  

 

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Figure 7‐2: MEPAU’s Risk Matrix 

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Table 7-1: Construction Phase ERA

Source of Potential Emission / Discharge 

Potential Emission / Discharge 

Potential Receptors  Volume / Frequency  Proposed Applicant Controls  Residual Risk 

The operation of vehicle and machinery and clearing/disturbing hardstand areas during the construction phase 

Atmospheric Emissions – Dust 

No residences or other sensitive receptors in proximity.  

Closest residences (dust) are 3.5km south west, 3.8km north east and 4.5km north west. 

Closest residences (noise) are 3.5km south west and 3.8km north east. 

Incidental dust generation for the duration of construction – estimated duration of ~6 months. 

Speed limits for vehicles 

Complaints management system: 

o MEPAU will record all complaints associated with atmospheric emissions including the details of complaints received, and any action taken in response to the complaint 

Low

Noise Emissions  Noise levels modelled  to be <35 dB at sensitive receptor locations (two residences) for the duration of construction – estimated duration of ~6 months. 

Restricted night‐time activities 

Complaints management system: 

o MEPAU will record all complaints associated with noise emissions including the details of complaints received, and any action taken in – response to the complaint 

Low 

Stormwater design within the XPF 

Uncontained spill event – water contaminated with hydrocarbons (if inadequately designed at construction phase) 

Yaragadee aquifer An evaluation of spill scenarios indicate this type of event may result in an incidental  release of contaminated stormwater and is likely to be an infrequent event. 

Infrastructure with concrete foundations are bunded 

Sumps installed to retrieve runoff 

Vacuum trailer used when required to drain sumps 

Low

Evaporation pond construction 

Spill event – water contaminated with hydrocarbons (if inadequately designed at construction phase) 

Yaragadee aquifer  There is no spill risk from the evaporation pond during construction, however construction controls will manage the risk of a spill during operations. 

New evaporation pond design considerations (including WQPN 26): 

o Prepared hardstand area free of debris 

o Liner thickness 1.5mm 

o Freeboard minimum of 0.5m 

Low 

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Table 7-2: Commissioning Phase ERA

Source of Potential Emission / Discharge 

Potential Emission / Discharge 

Potential Receptors  

Volume / Frequency  Proposed Applicant Controls  Residual Risk 

The operation of vehicle and machinery during the commissioning phase 

Atmospheric Emissions ‐ Dust 

No residences or other sensitive receptors in proximity.  

Closest residences (dust) are 3.5km south west, 3.8km north east and 4.5km north west Closest residences (noise) are 3.5km south west and 3.8km north east. 

Incidental dust generation for the duration of commissioning phase ~2 months as a short term impact only. 

Speed limits (<50 km/h) 

Complaints management system: 

o MEPAU will record all complaints associated with atmospheric emissions including the details of complaints received, and any action taken in response to the complaint 

Low 

Commissioning of the upgraded equipment and infrastructure within the XPF – hydrocarbon gas 

Atmospheric Emissions ‐ gas and particulates 

Atmospheric emissions during the commissioning phase are expected to similar to operations, with any variation limited to a short period during commissioning. 

Refer to Section 6.1.2. and Table 3. 

Planned release to air at height to support increased dispersion (i.e. the plant vent is located 5m above ground) 

Environmental Commissioning Management Plan (2019) 

Low 

Commissioning of the upgraded equipment and infrastructure within the XPF – hydrocarbon gas 

Noise Emissions  Noise emissions during the commissioning phase are expected to similar to operations, with any variation limited to a short period during commissioning. 

Refer to Section 6.1.3. 

Restricted night time activities 

Complaints management system: 

o MEPAU will record all complaints associated with noise emissions including the details of complaints received, and any action taken in response to the complaint 

Low

Produced Formation Water transport via waterline) 

PFW ‐ unplanned spill event 

Yaragadee aquifer  Based on the pipe design, it is unlikely that a spill event will occur. 

Pressure testing will be carried out on the water pipe during commissioning to confirm its integrity 

Low 

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Table 7-3: Operations ERA

Source of Potential Emission / Discharge 

Potential Emission / Discharge 

Potential Receptors   Volume / Frequency  Proposed Applicant Controls  Residual Risk 

Separation and processing of gas ‐ Operation of gas compressor, Gas Engine Alternator (GEA), and vents6 at the XPF 

Atmospheric Emissions ‐ gas and particulates 

No residences or other sensitive receptors in proximity.  

Closest residences are 3.5km south west, 3.8km north east and 4.5km north west. 

XPF production capacity of 30 TJ/day of gas. 

Emissions and volume sources are described in Section 6.1.2. and Table 3. 

Annual point source monitoring of total gas vented at Plant Vent (denoted as F on Attachment 6A) 

Low

Maintenance – depressurisation of the plant vent7 

Atmospheric Emissions – gas and particulate 

No residences or other sensitive receptors in proximity.  

Closest residences are 3.5km south west, 3.8km north east and 4.5km north west. 

Emissions are only generated from the plant vents during plant maintenance when the plant needs to be depressurised, or during compressor shutdowns during maintenance. 

Emissions and volume sources are described in Section 6.1.2. and Table 3. 

Annual point source monitoring of total gas vented at Plant Vent (denoted as F on Attachment 6A) 

Planned release to air at height to support increased dispersion (i.e. the plant vent is located 5m above ground) 

Low 

Operation of gas compressor, generator, methanol injection pump, and Low Temperature Separator at the XPF 

Noise Emissions   No residences or other sensitive receptors in proximity.  

Closest residences are 3.5km south west and 3.8km north east. 

Noise levels modelled  to be <35 dB at sensitive receptor locations (two residences) for the duration of operations. 

Compressor exhaust system has a “Hospital Pack” silencer fitted  

Mufflers installed on the methanol injection pumps air discharge nozzles 

Joule‐Thompson valve on the Low Temperature Separator will be replaced by a low noise valve 

Complaints management system: 

o MEPAU will record all complaints associated with 

Low

6 Includes gas breakout tank vent and liquids storage tank vent 7 Does not operate under normal conditions 

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Source of Potential Emission / Discharge 

Potential Emission / Discharge 

Potential Receptors   Volume / Frequency  Proposed Applicant Controls  Residual Risk 

noise emissions including the details of complaints received, and any action taken in response to the complaint 

Produced Formation Water storage (Waitsia‐02 evaporation pond via waterline) 

PFW ‐ unplanned spill event 

Yaragadee aquifer Based on the pond design and existing controls, it is unlikely that a spill event will occur, and any spill event is expected to be small in volume. 

Volume of PFW transferred to the new evaporation pondmonitored via a flow meter

Tanker volumes are recorded for transport of PFW to theHPF as per current practice

Visual monitoring inspection of freeboard (water depthmarker)

Regular visual  inspection of waterline (above groundsection) for evidence integrity failure

Perth Basin Surveillance Sampling Program [PB‐HSE‐PRO‐119] ‐ continuation of existing groundwater monitoringprogram (which will detect if any hydrocarbons within boresdownstream of the Waitsia‐02 evaporation pond)

Low

Stormwater management within the XPF 

Spill event – water contaminated with hydrocarbons 

Yaragadee aquifer  An evaluation of spill scenarios indicate this type of event may result in an incidental  release of contaminated stormwater and is likely to be an infrequent event. 

Concrete foundations bunds are inspected and clean waterdrained to grade. Contaminated water will be vacuumed out.

Sumps are monitored monthly and vacuumed out asrequired

Hydrocarbon contaminated stormwater from cleaned outbunds and sumps is transported offsite and disposed of at anappropriately licenced facility (usually DPF)

Low 

Vehicular movements and exposed hardstand areas 

Atmospheric Emissions – Dust 

No residences or other sensitive receptors in proximity.  

Closest residences are 3.5km south west, 3.8km north east and 4.5km north west. 

Traffic movements during operations will be limited, and dust generation is expected to be incidental. 

Complaints management system:

o MEPAU will record all complaints associated withatmospheric emissions including the details ofcomplaints received, and any action taken inresponse to the complaint

Speed limits (<50 km/h)

Low 

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Source of Potential Emission / Discharge 

Potential Emission / Discharge 

Potential Receptors   Volume / Frequency  Proposed Applicant Controls  Residual Risk 

Operation of the evaporation pond 

Odour Emissions  No residences or other sensitive receptors in proximity.  

Closest residences are 3.5km south west, 3.8km north east and 4.5km north west. 

Based on the pond design and historical operations in the area, it is unlikely that odour emissions will impact sensitive receptors beyond the Premises boundary. 

Complaints management system: 

o MEPAU will record all complaints associated with odour emissions including the details of complaints received, and any action taken in response to the complaint 

 

 

 

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8.0 OTHER APPROVALS AND CONSULTATION DOCUMENTATION 

MEPAU are committed to stakeholder engagement and their commitment  is documented  in their Stakeholder Engagement Plan [CP‐PM‐039] which includes: 

Identification and analysis of stakeholder groups, 

Adopted method of communication with each stakeholder group, 

Determination  of  the  type  of  information  that  is  required  to  be  communicated  and when, 

Confirmation  of  the  MEPAU  resource  that  is  responsible  for  implementing  the commitments outlined in this EP, 

Reporting  responsibilities  and  relationships  during  communication  and  consultation processes, 

A list of contacts and the contact details for all key stakeholders, 

A  calendar  of  activities  (including  how,  when,  to  and  by  whom  communications  and consultations will occur), and 

A  point  of  reference  for  the  specific  obligations,  commitments  and  requirements relating  to  those  stakeholders,  including  those  defined  within  resource  consents  and third‐party agreements. 

MEPAU maintains a database of  stakeholder  communication and are committed  to ongoing consultation  and  open  dialogue  with  key  stakeholders  for  the  duration  of  the  project.  In addition  to  direct  engagement,  MEPAU  hosts  a  Mid‐West  website (www.mitsuiepmidwest.com.au)  that  includes project  specific pages, blogs, a  feedback  form and hyperlinks to other websites. The website provides an additional method for MEPAU to communicate with stakeholders on a continuing basis.  

MEPAU  (and  previous  operators  AWE)  have  routinely  engaged  with  the  following  list  of stakeholders regarding projects within the Waitsia gas field: 

routinely engaged with the following list of stakeholders: 

Landowners, directly and indirectly affected, including: 

A. Whitmarsh (Revive Nominees Pty Ltd), 

S. Micke (Wongulla Park Pty Ltd), 

Irwin Park Farm (AWE), lessee P. Kupsch (Tara Farming); and  

C. Forsyth (Avoca Farm). 

Neighbouring operators – APA, Patience Bulk Haulage 

Government agencies: 

Department of Biodiversity, Conservation and Attractions (DBCA), 

DWER, 

Department of Fire and Emergency Services (DFES), 

DMIRS, and 

Mid‐west Development Commission (MWDC) 

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Traditional owners – Southern Yamatji, Widi Mob and Yued 

Joint Venture Partner – Beach Energy (Lattice Energy Resources (Perth Basin) Pty Ltd) 

Local stakeholders: 

Local Business owners and service providers 

Dongara and Port Denison residents, and 

Mid‐west Chamber of Commerce and Industry 

Local government (staff and elected officials): 

Shire of Irwin, 

City of Greater Geraldton, and 

Shire of Carnamah. 

During  preparation  of  the  DMIRS  Construction  Environment  Plans,  MEPAU  completed  a scoping exercise to determine which authorities, persons and organisations were relevant for the WS1E Project  activities  covered under  the EPs.   As  the  assets  are  in  regional  areas  and distant from any town sites, the following key stakeholders were identified: 

Landowners of the properties where the assets are located, and adjacent to them, 

Local government (Shire of Irwin), and  

Southern Yamatji people (Traditional Landowners). 

A  summary of  the most  recent  consultation undertaken  specific  to  activities  covered under this Works Approval Application is detailed in Table 8‐1 below. 

Table 8-1: Stakeholder Consultation Undertaken

Stakeholder  Date  Summary of Consultation  

DWER ‐ Industry 

Regulation 

Branch 

17 July 2019 – Scoping meeting

Phone call/emails ‐ ongoing 

Scoping meeting to present the WS1E Project, 

and discuss the Part V submission process and 

information requirements 

Shire of Irwin  Various engagements over 

August / September 2019 

Notified regarding the Pipeline Licence 

Application and advice sought regarding the 

pipeline road crossings. No Development 

Applications required. 

YMAC  Various engagements over 

August / September 2019 

Heritage survey liaison 

Southern Yamatji 

Working Group 

and MEPAU 

Meeting (informal) 7 February 

2019 ‐ Senior representatives 

Activities update including Waitsia Gas Project.  

Key area of interest was potential training and 

employment opportunities arising from future 

projects. 

Landowners  Ongoing  A number of land access agreements are in place 

as described in Section 3.1.   

Advised of design changes to the WS1E Project 

(fencing, pipeline routing etc), notified regarding 

the Pipeline Licence Application and heritage 

survey. 

Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

 

P‐WGP1‐023 Rev A  Page 56 of 64 

9.0 ADDITIONAL INFORMATION SUBMITTED 

 

 

 

Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

P‐WGP1‐023 Rev A  Page 57 of 64 

Attachment 8A – Air Dispersion Modelling Report (Ramboll, 2019) 

Intended for

Mitsui E&P Australia Group

Document type

Final Report

Date

July 2019

XYRIS PRODUCTION

FACILITY

AIR DISPERSION

MODELLING

Ramboll Australia Pty Ltd.

ACN 095 437 442

ABN 49 095 437 442

Ramboll

Suite 3, Level 2

200 Adelaide Terrace

East Perth

WA 6004

Australia

T +61 8 9225 5199

F +61 8 9225 5155

https://ramboll.com

XYRIS PRODUCTION FACILITY

AIR DISPERSION MODELLING

Project name Xyris Production Facility – Air Dispersion Modelling

Project no. 318000686

Recipient Mitsui E&P Australia Group

Document type Report

Version Final

Date 5/7/2019

Prepared by Martin Parsons

Checked by Ruth Peiffer

Approved by John Miragliotta

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CONTENTS

1. Introduction 3 2. Atmospheric Emissions 5 2.1 Introduction 5 2.2 Xyris Production Facility Emissions 5 2.3 Other Regional Emission Sources 5 2.3.1 Mondarra Gas Storage Facility 5 2.3.2 Patience Sand Quarry 6 2.3.3 Hovea Production Facility 6 2.4 Emissions Scenarios 6 2.5 Emissions Rates 6 2.6 Summary 7 3. Impact Assessment Criteria 12 3.1 Ambient Air Quality 12 3.2 Workplace Exposure Standards 14 4. Atmospheric Dispersion Modelling 16 4.1 Important Dispersion Processes to be Modelled 16 4.1.1 Plume Rise above the Stable Boundary Layer 16 4.1.2 Morning Fumigation 16 4.1.3 Plume Downwash due to Nearby Structures 16 4.1.4 Convective Dispersion 16 4.1.5 Terrain Effects on Airflow 16 4.1.6 Inclusion of Other Regional Sources – Cumulative Assessment 16 4.2 Model Selection 16 4.3 Meteorological Processing 16 4.3.1 Model Validation against Meteorology 18 4.4 CALPUFF Model Set Up 19 4.5 Short Term Averaging Periods 20 4.6 Treatment of Oxides of Nitrogen 20 4.7 Ozone 20 4.8 Receptors 21 4.9 Building Downwash 21 4.10 Background Concentrations Used in the Modelling 21 5. Predicted Concentrations 23 6. Conclusions 33 7. References 34

TABLES Table 1: Source Parameters and Emission Rates for XPF 8

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Table 2: Source Parameters and Emission Rates for Mondarra Gas

Storage Facility 10 Table 3: Sand Mining Emissions Rates 10 Table 4: Source Parameters and Emission Rates for Hovea Facility 11 Table 5: National Environment Protection (Ambient Air Quality) Measure

Ambient Air Quality Standards and Goals 12 Table 6: National Environment Protection (Air Toxics) Measure Ambient

Air Quality Monitoring Investigation Levels 13 Table 7: Ambient Air Quality Standards Applicable to XPF 14 Table 8: Workplace Exposure Standards 15 Table 9: Distribution of Wind Speeds for 2018 (CALMET-Generated Data) 18 Table 10: Receptor Locations (UTM coordinates) 21 Table 11: Nominated Background Concentrations for Pollutants 22 Table 12: Predicted Concentrations and Percentage of Guideline without

Background at Sensitive Receptor 1 25 Table 13: Predicted Concentrations and Percentage of Guideline with

Background at Sensitive Receptor 1 26 Table 14: Predicted Concentrations and Percentage of Guideline without

Background at Sensitive Receptor 2 27 Table 15: Predicted Concentrations and Percentage of Guideline with

Background at Sensitive Receptor 2 28 Table 16: Predicted Concentrations and Percentage of Guideline without

Background at Sensitive Receptor 4 29 Table 17: Predicted Concentrations and Percentage of Guideline with

Background at Sensitive Receptor 4 30 Table 18: Predicted Concentrations and Percentage of Guideline without

Background at Onsite Receptor 31 Table 19: Predicted Concentrations and Percentage of Guideline with

Background at Onsite Receptor 32

FIGURES Figure 1. Overview of Project Location 4 Figure 2. CALMET Generated Wind Rose 17 Figure 3. Annual (2018) Wind Rose from BOM measured dataset from

Geraldton Airport 19 Figure 4. Maximum Predicted 1-hour Average GLCs of NO2 for

Cumulative Operations Without Nominated Background Concentrations 24

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1. INTRODUCTION

AWE Perth Pty Ltd is a wholly owned subsidiary of AWE Limited. Mitsui E&P Australia Pty Ltd and

AWE Ltd are wholly owned subsidiaries of Mitsui & Co. Ltd. Combined they form the unified brand

Mitsui E&P Australia Group (MEPAU). MEPAU is an oil and gas exploration and production business

with a head office located in Perth, Western Australia.

MEPAU manages the Waitsia Gas Field located on grazing land in the Shire of Irwin, about 19 km

south-east of Dongara and 367 km north of Perth (see Figure 1). The field sits within the

Geraldton Sandplains bioregion of Western Australia.

The Waitsia Gas Project is the largest conventional onshore Australian discovery in 40 years. It

currently consists of five oil and gas wells on petroleum permits L1 and L2. The field was

discovered in 2014 and has been developed in stages. The field is currently producing from two

wells, Waitsia-01 and Senecio-03 (collectively known as Waitsia Gas Project Stage 1). Wells

Waitsia-02, Waitsia-03 and Waitsia-04 wells are currently suspended.

Stage 1 of the project was commissioned in 2016 and achieved an output of ~10 TJ per day.

Stage 1 flowed gas from Waitsia-1 and Senecio-3 gas wells to the Xyris Production Facility (XPF)

owned by MEPAU and delivered treated gas for domestic use through the Parmelia Gas pipeline

(PGP).

The Xyris Expansion Project involves increasing production from ~10 TJ per day to 30 TJ per day

– and connecting the facility to the Dampier to Bunbury Natural Gas Pipeline (DBNGP) (it is

currently only connected to the Parmelia Gas Pipeline). With the capacity increase, emissions to

air will increase.

Ramboll Australia Pty Ltd (Ramboll) has been engaged by MEPAU to undertake air dispersion

modelling to assess the potential air quality impacts of atmospheric emissions from the proposed

expansion of the XPF, comparing the GLCs predicted at sensitive receptor locations against the

relevant ambient air quality criteria. This report presents the approach, methodology and results

of air dispersion modelling for the Facility operating under the nominated scenario.

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Figure 1. Overview of Project Location

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2. ATMOSPHERIC EMISSIONS

2.1 Introduction

This section provides details on the atmospheric emissions of concern from the proposed

expansion of the XPF and other sources in the region. Emissions of concern from the XPF are

oxides of nitrogen (NOX), sulphur dioxide (SO2), carbon monoxide (CO), particulate matter

including PM2.5 and PM10, VOCs (including benzene, toluene, ethylbenzene and xylene) (BTEX) and

mercury (Hg).

Besides the XPF sources, other emission sources that are significant in the region include the

Mondarra Gas Storage Facility (MGSF) and nearby sand mining operation.

2.2 Xyris Production Facility Emissions

Emission sources from the proposed expansion of the XPF include the following:

• Compressor gas engine – Compression will be undertaken by a 750kw CAT G3512 LE lean burn

four stroke. Emissions of concern are primarily considered to be NOX;

• Gas Engine Alternator (GEA) – Power will be supplied by a 100kw Cummins CG6L-8G1 lean

burn four stroke model engine. Emissions of concern are primarily considered to be NOX;

• Vents – The vents include a gas breakout tank vent, a liquids storage tank vent and a plant

vent. The plant vents are only used during plant maintenance when the plant needs to be de-

pressured. Emissions of concern include BTEX and Hg.

• Two process water ponds including an evaporation pond and a turkey nest. Both ponds can

contain some trace amounts of hydrocarbon and so have been included as fugitive emissions

sources.

• Vehicular combustion sources – Motor vehicles are considered a negligible source of

atmospheric emissions (during both construction and operation), though they can result in

relatively high ground level concentrations (GLCs) immediately adjacent to highly trafficked

roads under stable, light wind conditions; and

• Fugitive dust from motor vehicle traffic, construction emissions and nearby exposed surfaces.

This source is difficult to quantify accurately and therefore model and is considered best

addressed through a monitoring and management program.

2.3 Other Regional Emission Sources

Other sources considered as part of this assessment include the MGSF, the Patience Sand Quarry

and the Hovea Production Facility.

2.3.1 Mondarra Gas Storage Facility

The MGSF operates approximately 3 km to the east of the XPF as shown in Figure 1. The MGSF is

located between two major pipelines that service Perth: the Parmelia Pipeline and the Dampier to

Bunbury Natural Gas Pipeline (DBNGP). The MGSF includes the following sources of emissions to

air:

• Flare – A small quantity of gas will be vented through a permanently lit flare. The gas that

reaches the flare is used to maintain a blanket of gas over the liquids, effectively preventing

ingress of air into the vessels. The flare can operate under either normal conditions, whereby

the facility is in injection mode for 2/3 of the time and in withdrawal mode for 1/3 of the time,

or under blow-out conditions, expected to only occur under extreme circumstances on a less

that one hour per year basis.

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• A vent is maintained at the site for emergency purposes and for purging gas from equipment

prior to maintenance.

• Power Generation and Compressors – The MGSF has two natural gas powered 3.2 MW

compressor reciprocating engines as well as two 300 kVA natural gas powered GEAs operating.

All emissions information was obtained from a previous modelling assessment as supplied by the

APA Group (Synergetics, 2011).

2.3.2 Patience Sand Quarry

A sand quarry excavating and transporting 3000 tonnes per year of sand operates approximately

1 km to the south of the XPF as shown in Figure 1. The main sources of emissions associated with

the quarry include the excavation and loading of the product, wind erosion of the quarry and the

transport of the product.

2.3.3 Hovea Production Facility

The Hovea Production Facility is located approximately 5 km to the west of the XPF as shown in

Figure 1. It is currently under care and maintenance with no known plans to operate into the

future. The Hovea Production Facility does have an evaporation pond and a sump where stored

water can contain some trace amounts of hydrocarbon. The evaporation ponds have been

included in this assessment as fugitive sources.

2.4 Emissions Scenarios

For the operation of the XPF, there are some variations in the emissions that can occur. For this

modelling assessment, these are simplified into normal operations and maintenance operations.

Normal operations at the XPF includes emissions from the GEA, the compressor, the gas breakout

tank vent and the liquids storage tank vent. The plant vent does not operate under normal

conditions. The plant vents are only used during plant maintenance when the plant needs to be

de-pressured.

Maintenance operations at the XPF includes emissions from the GEA and the plant vent only. The

compressor and other vents are not operated. It is expected that maintenance will only occur for

a small number of hours each year, and as such this assessment has focussed on short term

impacts (i.e. less than 24 hours) for this scenario.

2.5 Emissions Rates

Emission rates for the XPF sources were derived from a number of sources; the GEA and

compressor emission rates were derived from fuel consumption rates and emission factors from

the National Pollutant Inventory (NPI) Combustion Sources Emissions Estimations Manual (NPI,

2008). Emissions rates for all other XPF sources were derived from data provided by MEPAU.

Emissions estimates for the sand quarry were derived from handling, wind erosion and haulage

emissions factors outlined in the NPI Mining Emissions Estimations Manual (NPI, 2012).

Emission rates from the ponds were determined using the USEPAs WATER9 program which

consists of analytical expressions for estimating air emissions of individual waste constituents in

wastewater collection, storage, treatment, and disposal facilities.

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2.6 Summary

A summary of the source parameters and emissions rates for the proposed expansion of the XPF,

as well as the MGSF, Hovea Production Facility and sand mining operations utilised in this

assessment are presented in Table 1 to Table 4.

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Table 1: Source Parameters and Emission Rates for XPF

Emission Source Gas Engine

Generator

Export Gas

Compressor

Engine4

Gas

Breakout

Tank3

Liquids

Storage

Tank2

Plant Vent1 Sump Turkeys Nest

Zone 50 J 50 J 50 J 50 J 50 J 50 J 50 J

Easting (mE) 314732 314749 314708 314704 314755 314862.4 314863.3

Northing (mN) 6756440 6756482 6756465 6756464 6756478 6757086 6757130

Capacity (kw) 100 750 N/A N/A N/A N/A N/A

Stack Height (m) 2 5 8 8 5 N/A N/A

Stack Internal Diameter (m) 0.114 0.179 0.29 0.146 0.1 N/A N/A

Exit Velocity (m/s) 9.6 24.5 0.09 0.01 245 N/A N/A

Mass Rate (kg/hr) 417 2651 24 0.7 5200 N/A N/A

Mass Rate (kg/hr) HP N/A N/A N/A N/A N/A N/A N/A

Mass Rate (kg/hr) LP N/A N/A N/A N/A N/A N/A N/A

Temperature (oC) 300-400 300-400 23 20-30 0 to -5 25 25

Dimensions N/A N/A N/A N/A N/A 33mx33mx2.5m 35mx25mx2.5m

Emission Rates

NOx 1.30E-01 8.28E-01 N/A N/A N/A N/A N/A

CO 8.54E-02 5.44E-01 N/A N/A N/A N/A N/A

PM2.5 1.18E-05 7.53E-05 N/A N/A N/A N/A N/A

PM10 1.18E-05 7.53E-05 N/A N/A N/A N/A N/A

SO2 1.19E-04 7.58E-04 N/A N/A N/A N/A N/A

Benzene 2.75E-03 1.73E-02 1.67E-04 4.70E-06 5.40E-02 2.37E-04 3.46E-04

Toluene 2.16E-03 1.36E-02 1.31E-04 3.69E-06 4.24E-02 1.08E-04 1.61E-04

Ethylbenzene 1.83E-04 1.15E-03 1.11E-05 3.12E-07 3.58E-03 3.88E-06 5.76E-06

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Emission Source Gas Engine

Generator

Export Gas

Compressor

Engine4

Gas

Breakout

Tank3

Liquids

Storage

Tank2

Plant Vent1 Sump Turkeys Nest

Xylenes 8.46E-04 5.32E-03 5.13E-05 1.44E-06 1.66E-02 8.31E-05 1.25E-04

Hg 4.67E-08 2.94E-07 2.83E-09 7.98E-11 9.17E-07 4.14E-07 4.39E-07

Notes:

1. Plant vents are only used during plant maintenance when the plant needs to be depressured. Gas rate is based on 9000 kPag upstream pressure and 12 mm orifice. Vent height

assumed to be 5 m above grade (supported by compressor roof structure).

2. Liquid storage tank vent rate is based on liquid discharge rate into the tank (from H&MB stream 180) as it is assumed that entrained gas flashes off in gas breakout tank.

3. Process data obtained from 25 TJ/d H&MB stream 181. Gas density is 1.1 kg/m3 and MW = 27.6.

4. Compressor and GEA engine exhaust gas rate is based on stiochiometric combustion of fuel gas, fuel gas use is 33 Sm3/h (23.7 kg/h) for the generator (Cummings CG6L-8G1) and

210 Sm3/h (150 kg/h) for the compressor (Cat 3512). Calculation assumes 9.5 m3 of air (density = 1.25 kg/m3) for each m3 of gas (density 0.75 kg/m3) for full combustion.

5. Emissions factors of criteria pollutants are from Table 54 of Combustion engines EET, assuming load of less than 90%.

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Table 2: Source Parameters and Emission Rates for Mondarra Gas Storage Facility

Emission Source

Export Gas

Compressor

Engine

Gas Engine

Generator Flare

Total Quantity 2 2 1

Quantity Operating 2 2 1

Stack Height (m) 9 9 12.6

Stack Internal Diameter (m) 0.3 0.2 4.5

Exit Velocity (m/s) 15 21 0.14

Temperature (oC) 460 450 1000

Emission Rates

NOx 3.31E+00 4.14E-01 2.03E-02

CO 2.17E+00 2.72E-01 1.17E-01

PM2.5 2.78E-04 2.78E-05 1.67E-03

PM10 2.78E-04 2.78E-05 1.67E-03

SO2 3.06E-03 2.78E-04 0.00E+00

Benzene 1.67E-03 2.78E-04 5.56E-07

Toluene 1.67E-03 2.78E-04 8.33E-07

Ethylbenzene 2.78E-04 2.78E-05 0.00E+00

Xylenes 8.33E-04 8.33E-05 0.00E+00

Hg 0.00E+00 0.00E+00 0.00E+00

Locations

Zone 50 J 50 J 50 J

Easting - Unit 1 (mE) 317215 317115 317332

Northing - Unit 1 (mN) 6756189 6756164 6756254

Easting - Unit 2 (mE) 317214 317116

Northing - Unit 2 (mN) 6756211 6756150

.

Table 3: Sand Mining Emissions Rates

Source Unit PM10 PM2.5

Excavation and Loading (8.0 t/day) g/s 0.027 0.0136

Wind Erosion (6.54 Ha) g/s 0.36 0.18

Haulage 300 m x 2 X Trucks/Day1 g/s 0.011 0.0055

Notes:

1. Assumed 82 t total load from 50 t haul truck https://www.cat.com/en_AU/products/new/equipment/off-highway-

trucks/off-highway-trucks/18256246.html

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Table 4: Source Parameters and Emission Rates for Hovea Facility

Emission Source Evaporation

Pond Turkeys Nest

Zone 50 J 50 J

Easting (mE) 309752 309735

Northing (mN) 6755033 6755144

Temperature (oC) 25 25

Dimensions 45mx35mx1m 29mx24mx1.5m

Emissions Rates

Benzene 5.47E-04 2.08E-04

Toluene 2.85E-04 1.00E-04

Ethylbenzene 1.03E-05 3.59E-06

Xylenes 2.11E-04 7.66E-05

Hg 2.40E-07 1.59E-07

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3. IMPACT ASSESSMENT CRITERIA

3.1 Ambient Air Quality

In February 2017, the DWER published the Guidance Statement for Risk Assessments (DER,

2017) which lists Specific Consequence Criteria to be considered in determining public health and

environment impacts. The publications containing air quality criteria relevant to this assessment

include:

• National Environment Protection (Ambient Air Quality) Measure (NEPC, 2016);

• National Environment Protection (Air Toxics) Measure (NEPC, 2011); and

• Approved Methods for the Modelling and Assessment of Air Pollutants in New South Wales

(NSW EPA, 2016).

The National Environment Protection (Ambient Air Quality) Measure specifies standards and goals

for a range of pollutants relevant to this assessment, including CO, NO2, SO2, PM10 and PM2.5

(Table 5).

Table 5: National Environment Protection (Ambient Air Quality) Measure Ambient Air Quality Standards and

Goals

Pollutant Averaging

period

Maximum concentration

standard1

Maximum allowable

exceedances

Carbon monoxide 8 hours 10,000 µg/m3 1 day a year

Nitrogen dioxide 1 hour

1 year

246 µg/m3

62 µg/m3

1 day a year

None

Sulphur dioxide

1 hour

1 day

1 year

570 µg/m3

228 µg/m3

60 µg/m3

1 day a year

1 day a year

None

Particles as PM10 1 day

1 year

50 µg/m3

25 µg/m3

None

None

Particles as PM2.5 1 day

1 year

25 µg/m3

8 µg/m3

None

None

Notes:

1. Referenced to 0ºC, and 101.3 kPa

The National Environment Protection (Air Toxics) Measure specifies monitoring investigation levels

for several key pollutants relevant to this assessment, including BTEX, established for use in

assessing the significance of monitored levels of air toxics with respect to protection of human

health as outlined in Table 6.

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Table 6: National Environment Protection (Air Toxics) Measure Ambient Air Quality Monitoring Investigation

Levels

Pollutant Averaging

period

Monitoring

investigation level1 Goal

Benzene Annual average 9.6 µg/m3

8-year goal is to gather sufficient data

nationally to facilitate development of a

standard.

Toluene 24 hours

Annual average

3769 µg/m3

377 µg/m3

8-year goal is to gather sufficient data

nationally to facilitate development of a

standard.

Xylenes (as total of ortho,

meta and para isomers)

24 hours

Annual average

1085 µg/m3

868 µg/m3

8-year goal is to gather sufficient data

nationally to facilitate development of a

standard.

Notes:

1. Referenced to 0ºC, and 101.3 kPa

The NSW EPA (2016) specifies statutory impact assessment criteria for modelling and assessing

emissions of air pollutants from stationary sources. Impact assessment criteria have been

established for various individual toxic air pollutants and for individual odorous air pollutants,

including (but not limited to) mercury and BTEX. The NSW EPA (2016) impact assessment criteria

for inorganic mercury, benzene and ethylbenzene are based on toxicity to humans.

For the purposes of assessing potential impacts upon human health, additional ambient air quality

criteria are often adopted from the World Health Organisation (WHO) for mercury. The WHO has

published a Concise International Chemical Assessment Document (CICAD) for Elemental Mercury

and Inorganic Mercury Compounds: Human Health Aspects (WHO, 2003), which determines a

tolerable concentration of 0.2 µg/m3 for long-term inhalation exposure to elemental mercury

vapour.

DWER recommends that for each pollutant modelled, the assessment must account for existing

concentrations caused by other sources plus (if significant) the background concentration

(whether natural or man-made) to estimate the cumulative concentration.

For the contribution to be properly assessed, DWER requires modelling results (as described in the

foregoing point) to be presented for:

• The existing emissions plus background concentration (pre-proposal);

• The proposed development in isolation (excluding existing emissions); and

• The combined (existing plus proposed plus background) emissions.

A summary of the standards applicable for this assessment are summarised in Table 7 below.

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Table 7: Ambient Air Quality Standards Applicable to XPF

Pollutant Averaging

Period

Ambient Air

Concentration

(µg/m3)1

Type Reference

Carbon monoxide 8 hours 10,000 human health NEPC (2016)

Nitrogen dioxide 1-hour 246 human health NEPC (2016)

Annual 62 human health NEPC (2016)

Sulphur dioxide

1-Hour 570 human health NEPC (2016)

24-Hour 228 human health NEPC (2016)

Annual 60 human health NEPC (2016)

Particles as PM10 24-Hour 50 human health NEPC (2016)

Annual 25 human health NEPC (2016)

Particles as PM2.5 24-Hour 20[2] human health NEPC (2016)

Annual 7[2] human health NEPC (2016)

Mercury inorganic 1-hour 1.8 human health NSW EPA (2016)

Annual 0.2 human health WHO (2003)

Benzene 1-hour 29 human health NSW EPA (2016)

Annual 9.6 human health NEPC (2011)

Ethylbenzene 1-Hour 7,344 human health NSW EPA (2016)

Toluene

1-Hour 330 human health NSW EPA (2016)

24-hour 3,769 human health NEPC (2011)

Annual 377 human health NEPC (2011)

Xylene

1-hour 174 human health NSW EPA (2016)

24-hour 1,085 human health NEPC (2011)

Annual 868 human health NEPC (2011)

Notes:

1. Referenced to 0ºC, and 101.3 kPa

2. PM2.5 concentrations presented are from proposed 2025 changes to National Environment Protection (Ambient Air

Quality) Measure.

3.2 Workplace Exposure Standards

Workplace exposure standards for approximately 700 substances and mixtures have been

established in Australia by Safe Work Australia, an Australian government statutory body. These

are legal concentration limits that must not be exceeded. Workplace exposure standards are

generally less conservative than ambient air quality standards to account for the general health of

the workforce and shorter exposure times. Relevant workplace exposure standards are presented

in Table 8.

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Table 8: Workplace Exposure Standards

Pollutant Averaging

Period

Criteria

(µg/m3)1 Criteria Reference

NO2 15-Minute 9400 Safe Work Australia (2013)

8-Hour 5,600 Safe Work Australia (2013)

SO2 15-Minute 13,000 Safe Work Australia (2013)

8-Hour 5,200 Safe Work Australia (2013)

CO 8-hour 34,000 Safe Work Australia (2013)

Mercury 8-hour 25 Safe Work Australia (2013)

Benzene 8-hour 3,200 Safe Work Australia (2013)

Toluene

15-Minute 574,000 Safe Work Australia (2013)

8-Hour 191,000 Safe Work Australia (2013)

24-hour 3,769 NEPC (2011)

Ethylbenzene 15-Minute 543,000 Safe Work Australia (2013)

8-Hour 434,000 Safe Work Australia (2013)

Xylene

15-Minute 655,000 Safe Work Australia (2013)

8-Hour 350,000 Safe Work Australia (2013)

24-hour 1,085 NEPC (2011)

Notes:

1. Referenced to 0ºC, and 101.3 kPa

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4. ATMOSPHERIC DISPERSION MODELLING

4.1 Important Dispersion Processes to be Modelled

The relevant dispersion processes are dependent on the type of source, the topography, land use

variations and general wind patterns. For the sources considered, the following meteorology and

dispersion processes are important:

4.1.1 Plume Rise above the Stable Boundary Layer

Generally the buoyant plumes such as from the generators and compressors will penetrate any

low inversion and remain above the inversion.

4.1.2 Morning Fumigation

This occurs in the morning when the morning mixed layer grows to the plume height and the

plumes can be mixed rapidly to the ground. This phenomenon is generally considered to lead to

the highest concentrations for distances greater than 5 to 10 km from the sources.

4.1.3 Plume Downwash due to Nearby Structures

Downwash of the plume by the turbulent eddies that develop when air flows over and around

buildings. If the plume is emitted into or is caught in such an eddy, it can be brought to ground

much sooner than would otherwise occur, resulting in higher GLCs.

4.1.4 Convective Dispersion

During the day time, the heated earth’s surface will generate convective cells of rising and

descending air which can bring any plume to the ground within several hundred metres of the

source.

4.1.5 Terrain Effects on Airflow

Topography can impact significantly on air flow and therefore the dispersion of pollutants. The site

however is generally flat and undulating and as such is considered to have only a minimal impact

on dispersion.

4.1.6 Inclusion of Other Regional Sources – Cumulative Assessment

For pollutants where there is a significant cumulative impact (i.e. background levels are

significant), the impact assessment needs to include existing regional sources and/or background

concentrations.

4.2 Model Selection

Due to the number of sources in the region located some distance from each other, the air

dispersion modelling has been using the CALPUFF air dispersion model with a meteorological

dataset from 2018.

4.3 Meteorological Processing

The closest meteorological monitoring stations with the applicable data available for this study

were Geraldton (~50km away) and Mullewa (~90km away). Due to the distances and the fact

that Geraldton is located on the coast and Mullewa is located in a semi-arid environment, neither

dataset was considered suitable for use in this assessment.

In the absence of suitable monitored data, the TAPM (The Air Pollution Model) prognostic

meteorological model developed by CSIRO was used to generate a gridded meteorological dataset

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for the modelling domain for 2018. The TAPM output was used as inputs into the CALMET

meteorological processor to develop a meteorological data file suitable for use in CALPUFF.

An annual wind rose generated by the CALMET meteorological processor using TAPM generated

data for the XPF site is presented in Figure 2, with the annual frequency of wind speeds presented

in Table 9.

Figure 2. CALMET Generated Wind Rose

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Table 9: Distribution of Wind Speeds for 2018 (CALMET-Generated Data)

Wind Speed Calms 0.5–1.5

m/s 1.5-3.0 m/s 3.0-4.5 m/s 4.5-6.0 m/s 6.0-7.5 m/s >7.5m/s

(%) 0.7 11.4 37.1 29.0 16.1 5.1 0.6

4.3.1 Model Validation against Meteorology

TAPM was used to generate the prognostic data for input into CALMET and then CALPUFF. The

ability of TAPM to predict meteorological variables has been verified at numerous sites around the

world (Hurley et al, 2004; Hurley, 2008). To verify the ability of the model to accurately predict

wind direction and speed for this study, the TAPM predictions have been compared against the

data from 3-hourly averaged data from the Bureau of Meteorology (BOM) meteorological

monitoring station in Geraldton [Site name: Geraldton Airport, Site number: 008315,

Latitude: 28.80° S, Longitude: 114.70° E, Elevation: 30 m (BOM 2019)].

Figure 3 presents the BOM meteorological station in Geraldton Airport. Some differences are

expected when compared against the prognostic data as outline in Figure 2 due to the distance

between the two locations and their distances from the coast: ~9 km and ~16 km, respectively.

The main differences observed are:

• BOM dataset from Geraldton Airport shows an overall higher proportion of stronger winds (>8

m/s) blowing mostly from the south, which is likely related to its greater proximity to the

coast;

• The prognostic-generated dataset for XPF presents a higher proportion of winds blowing from

the east and northeast.

For the purposes of this assessment, the TAPM-generated dataset is considered representative of

the region and is deemed appropriate for use in this assessment.

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Figure 3. Annual (2018) Wind Rose from BOM measured dataset from Geraldton Airport

4.4 CALPUFF Model Set Up

The following model set up options within CALPUFF were used:

• Building downwash was included using the BPIP-Prime algorithms with site layout and

elevation. All buildings assessed to potentially influence sources were included in the

modelling;

• Grid spacings of 250 m over a 19 km x 19 km model domain were applied, centred

approximately on the site;

• No chemical transformation or deposition, except for the prediction of NO2 (as discussed in

Section 4.6);

A summary of the CALPUFF inputs applied in this assessment is provided in Appendix 1.

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4.5 Short Term Averaging Periods

Some workplace exposure standards are based on short term (15-minute) averages. However, air

dispersion modelling is generally undertaken in 1 hour time steps and in order to compare the

predicted concentrations against the nominated standards, a simple averaging-time scaling factor

was used to estimate short-term peak concentrations. This adjustment primarily addresses the

effect of meandering (fluctuations in the wind about the mean flow for the hour) on the average

lateral distribution of material. The scaling factor used to adjust the lateral dispersion coefficient1

for averaging time is the 1/5th power law:

Cl = Cs (60 / tl) 0.2

where

Cl = Concentration for new averaging period;

Cs = Concentration for the 1 hour average period;

tl = the averaging time (min.) of interest

4.6 Treatment of Oxides of Nitrogen

A key element in assessing the potential environmental impacts from ground level NO2

concentrations is estimating NO2 concentrations from modelled NOx emissions. The final NO2

concentration is a combination of the NO emitted as NO2 from the source stacks and the amount

of NO that is converted to NO2 by oxidation in the plume after release.

Generally, after the NOx is emitted from the stack, additional NO2 is formed as the plume mixes

and reacts with the surrounding air. There are several reactions that both form and destroy NO2,

but the primary reaction is oxidation with ozone according to the following reaction:

NO + O3 NO2 + O2

This reaction is essentially instantaneous as the plume entrains the surrounding air. It is limited

by the amount of ozone available and by how quickly the plume mixes with the surrounding air.

Thus the ratio of NO2 to NOx increases as the plume disperses downwind. After release, the NO is

converted to NO2 by chemical reactions, primarily involving ozone in the presence of sunlight and

to a lesser extent due to other reactive gases.

In order to predict NO2 concentrations, Ramboll has applied the US Environmental Protection

Agency (USEPA) Ozone Limiting Method (OLM). This method assumes that ozone is the limiting

reagent (i.e. the ozone concentration is less than the remaining NOx concentration) and requires

an NO2 to NOx in-stack ratio. In the absence of a site-specific in-stack ratio, it has been assumed

that 10% of NOx emissions are NO2 (a common assumption for gas combustion sources). Hourly

average ozone concentrations for application in the OLM were obtained from the Caversham

ambient air quality monitoring station as discussed in Section 4.10.

The OLM approach is considered conservative over short-term averaging periods as it assumes

the reaction between NOx and ozone occurs instantaneously, when in reality this is likely to take

place over a number of hours, during which time the plume is subject to dispersion.

4.7 Ozone

Photochemical smog is an air pollution problem commonly found in large cities. It is characterised

by high ozone concentrations at ground level, and can be generated through the interaction of

NOx and reactive organic compounds (ROC) which includes BTEX in the environment.

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The proposed XPF expansion is expected to be a relatively small emitter of NOx. Based on the

emission rates provided in Table 1 and assuming continuous release throughout the year, it is

estimated that the proposed XPF will emit approximately 30 tonnes of NOx and 5 tonnes of VOCs

annually.

By comparison, data from the NPI indicates a total of 760,000 tonnes of NOx were emitted to the

Kalgoorlie airshed for the 2018/2019 reporting year, where ozone is not considered a contaminant

of concern.

In considering these figures, and the likelihood that the surrounding region is unlikely have

elevated concentrations of ozone given its rural and remote settings, photochemical modelling of

NOx and VOC emissions from the XPF has not been undertaken as part of this assessment.

4.8 Receptors

Concentrations for all relevant compounds and averaging periods were predicted at three

farmhouses surrounding the facility as show in Figure 1 and at an onsite receptor to assess

occupational exposure impacts at site. Table 10 presents the locations of the dwelling and onsite

locations.

Table 10: Receptor Locations (UTM coordinates)

Receptor mE mN Type

Rec_001 311822 6755012 Dwelling

Rec_002 318515 6757359 Dwelling

Rec_003 314800 6756400 Onsite

Rec_004 310650 6758684 Dwelling

4.9 Building Downwash

According to modelling guidance “rules of thumb”, downwash should be considered when nearby

structures are more than 40% of the stack height. For the XPF sources, dimensions for the

compressor and GEA housings were provided by MEPAU and included as buildings. For the MGSF,

building information was obtained from the previous modelling assessment as supplied by the APA

Group (Synergetics, 2011).

4.10 Background Concentrations Used in the Modelling

The XPF is located in a remote location with no significant local sources of CO, SO2, NO2 or air

toxics (other than those included as sources in this assessment). Particulate matter could arise

from wind-blown dust but is still likely to be significantly lower than in a suburban environment

affected by road transport and other combustion sources. No background monitoring data was

identified in this assessment that was either in the immediate proximity of the study site or

deemed to be representative of this location. Rather, most ambient air quality monitoring sites

are located either in densely populated areas or near large known polluters in industrial zones.

The Western Australian Department of Water and Environment Regulation (DWER) collects air

quality data from a number of monitoring stations throughout the Perth, Kwinana, Southwest,

Kalgoorlie and Midwest regions of the state. Only two sites monitoring the pollutants of interest

were identified that were not in a densely populated area and were not under the strong direct

influence of a large polluting source: Caversham (NE suburbs of Perth) and Rolling Green (outer

east rural site). Data from Caversham (DWER, 2018) was used as the more conservative estimate

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(a semi-rural, outer suburban setting being more likely to have higher concentrations of most

pollutants compared with a rural one).

The Environment Protection Authority Victoria (Vic EPA) State Environment Protection Policy

(Ambient Air Quality) (SEPP (AQM)) (Gov. of Vic., 2001) recommends the 75th percentile

concentration (concentration which is exceeded by 25% of concentrations for that averaging

period) should be adopted as a background level for short term averages. For comparison against

the short term workplace exposure standards, the 1 hour average was utilised. Annual averages

were used for long term averages.

Table 11 presents a summary of the background concentrations obtained from the Caversham

monitoring station (2017) and utilised as part of this assessment. No representative background

data was available for Hg and BTEX, however it is unlikely that there are any significant sources of

these compounds, other than those modelled.

Table 11: Nominated Background Concentrations for Pollutants

Pollutant Averaging Period Representative Background

(µg/m3)

NO2 15-Minute 1-hour, 8-hour 39

Annual 10

SO2

15-Minute 1-hour, 8-hour 31

1-day 9

Annual 9

CO 8-hour 250

PM10 24-hour 20

Annual 16

PM2.5 24-hour 9

Annual 9

It should be noted that the annual average for PM2.5 is already in exceedance of the guideline. It is

unlikely that this is representative of conditions in the region, however in the absence of site

specific data, it has been utilised.

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5. PREDICTED CONCENTRATIONS

The following sections present the predicted concentrations of NO2, CO, SO2, PM10, PM2.5, Hg and

BTEX using the model CALPUFF. GLCs of the modelled compounds have been predicted within the

modelling domain. The predicted GLCs for the proposed expansion of the XPF operating both in

isolation and cumulatively with existing sources and background concentrations at the nominated

receptor locations, are summarised in Table 12 to 19.

Tables 12 to 17 present the predicted concentrations and the percentage of the ambient air

quality values, both with and without background concentrations, at the nominated sensitive

receptor locations. Tables 18 to 19 present the predicted concentrations and the percentage of

the workplace exposure standards, both with and without background concentrations, at the

nominated onsite receptor location.

The results of the air dispersion modelling assessment show that predicted GLCs for most

compounds in isolation and cumulatively are well below the corresponding ambient air quality and

workplace exposure standard criteria at the nominated receptor locations, with the exception of

the scenarios that consider annual average background concentrations of PM2.5. The annual

average background concentrations of PM2.5 were obtained from the Caversham monitoring

station and were already in exceedance of the guideline before consideration of emissions from

other sources. Given the rural nature and lack of industry in the region around the proposed

facility it is highly likely that the actual background concentrations of PM2.5 in the region are

significantly below the monitored concentrations at Caversham. The annual average

concentrations of PM2.5 predicted for the proposed expansion of the XPF and other existing

sources, without consideration of background concentrations, are equal to 4% of the annual

average PM2.5 guideline.

When considered without measured background concentrations, short term impacts from NO2

were predicted to be the main pollutant of concern from the XPF and MGSF, although predicted

concentrations remain well below the nominated guideline. Figure 3 presents a contour plot of

predicted cumulative concentrations of NO2 (under normal operations) in the region excluding

background.

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Figure 4. Maximum Predicted 1-hour Average GLCs of NO2 for Cumulative Operations Without Nominated

Background Concentrations

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Table 12: Predicted Concentrations and Percentage of Guideline without Background at Sensitive Receptor 1

Pollutant Averaging

Period

Criteria

(µg/m3)

Existing Xyris in Isolation Cumulative - Normal

Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 86 35% 50 20% 86 35% 86 35%

Annual Av 62 0.8 1% 0.3 0.5% 1.1 2% 0.9 1%

SO2

1-hour Max 570 0.09 0.02% 0.05 0.01% 0.09 0.02% 0.09 0.02%

24-hour Max 228 0.009 0.004% 0.01 0.005% 0.01 0.005% 0.01 0.004%

Annual Av 60 0.0007 0.001% 0.0003 0.0005% 0.001 0.002% 0.001 0.001%

CO 8-hour Max 10,000 44 0.4% 21 0.2% 44 0.4% 44 0.4%

PM10 24-hour Max 50 1.1 2% 0.001 0.002% 1.1 2% 1.1 2%

Annual Av 25 0.1 0.4% 0.00003 0.0001% 0.1 0.4% 0.1 0.4%

PM2.5 24-hour Max 25 1.1 4% 0.001 0.005% 1.1 4% 1.1 4%

Annual Av 8 0.1 1% 0.00003 0.0003% 0.1 1% 0.1 1%

Mercury 1-hour Max 2 0.00004 0.002% 0.00005 0.003% 0.00005 0.003% 0.0001 0.01%

Annual Av 0.2 0.0000001 0.0001% 0.0000003 0.0001% 0.0000004 0.0002% 0.000001 0.0005%

Benzene 1-hour Max 29 0.06 0.2% 1.1 4% 1 4% 6 22%

Annual Av 9.6 0.0007 0.007% 0.006 0.07% 0.007 0.07% 0.04 0.37%

Toluene 1-hour Max 330 0.05 0.02% 0.8 0.3% 0.8 0.3% 5 1.5%

Annual Av 377 0.0006 0.0001% 0.005 0.001% 0.006 0.001% 0.03 0.007%

Ethylbenzene 1-hour Max 7,344 0.01 0.0001% 0.07 0.001% 0.07 0.001% 0.4 0.006%

Xylene 1-hour Max 330 0.03 0.01% 0.3 0.10% 0.3 0.1% 1.9 0.6%

Annual Av 868 0.0003 0.00003% 0.002 0.0002% 0.002 0.0003% 0.01 0.001%

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Table 13: Predicted Concentrations and Percentage of Guideline with Background at Sensitive Receptor 1

Pollutant Averaging

Period

Criteria

(µg/m3)

Background Existing Xyris in Isolation Cumulative -

Normal Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 39 16% 125 51% 89 36% 125 51% 125 51%

Annual Av 62 10 16% 11 17% 10 17% 11 18% 11 18%

SO2

1-hour Max 570 31 5% 31 5% 31 5% 31 5% 31 5%

24-hour Max 228 9 4% 9 4% 9 4% 9 4% 9 4%

Annual Av 60 9 15% 9 15% 9 15% 9 15% 9 15%

CO 8-hour Max 10,000 250 3% 294 3% 271 3% 294 3% 294 3%

PM10 24-hour Max 50 20 40% 21 42% 20 40% 21 42% 21 42%

Annual Av 25 16 64% 16 65% 16 64% 16 65% 16 65%

PM2.5 24-hour Max 25 9 37% 10 41% 9 37% 10 41% 10 41%

Annual Av 8 9 113% 9 114% 9 113% 9 114% 9 114%

Notes:

Annual average background concentrations of PM2.5 are above the guideline before the addition of other regional and XPF sources. This data was obtained from the

Caversham monitoring station located in the Perth Metropolitan Area. Given its rural nature, it is likely that background PM2.5 concentrations will be significantly below

the concentrations presented as background in this table, however they have been included in this assessment for completeness.

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Table 14: Predicted Concentrations and Percentage of Guideline without Background at Sensitive Receptor 2

Pollutant Averaging

Period

Criteria

(µg/m3)

Existing Xyris in Isolation Cumulative - Normal

Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 117 48% 24 10% 117 48% 117 48%

Annual Av 62 1.8 3% 0.1 0.1% 1.9 3% 1.8 3%

SO2

1-hour Max 570 0.38 0.07% 0.02 0.00% 0.38 0.07% 0.38 0.07%

24-hour Max 228 0.059 0.026% 0.00 0.001% 0.06 0.026% 0.06 0.026%

Annual Av 60 0.0022 0.004% 0.0001 0.0001% 0.002 0.004% 0.002 0.004%

CO 8-hour Max 10,000 180 1.8% 10 0.1% 180 1.8% 180 1.8%

PM10 24-hour Max 50 2.1 4% 0.000 0.001% 2.1 4% 2.1 4%

Annual Av 25 0.05 0.2% 0.00001 0.0000% 0.0 0.2% 0.05 0.2%

PM2.5 24-hour Max 25 2.1 9% 0.000 0.001% 2.1 9% 2.1 9%

Annual Av 8 0.0 1% 0.00001 0.0001% 0.05 1% 0.05 1%

Mercury 1-hour Max 2 0.000004 0.0002% 0.00004 0.002% 0.00004 0.002% 0.0001 0.01%

Annual Av 0.2 0.00000001 0.000005% 0.0000001 0.0001% 0.0000001 0.0001% 0.0000003 0.0001%

Benzene 1-hour Max 29 0.21 0.7% 0.5 2% 0.5 2% 6 22%

Annual Av 9.6 0.0013 0.013% 0.002 0.02% 0.003 0.03% 0.01 0.1%

Toluene 1-hour Max 330 0.21 0.06% 0.4 0.1% 0.4 0.1% 5 1.5%

Annual Av 377 0.0013 0.0003% 0.001 0.000% 0.003 0.001% 0.01 0.003%

Ethylbenzene 1-hour Max 7,344 0.03 0.0005% 0.03 0.000% 0.03 0.0005% 0.4 0.006%

Xylene 1-hour Max 330 0.10 0.03% 0.2 0.05% 0.2 0.05% 2.0 0.6%

Annual Av 868 0.0006 0.00007% 0.001 0.0001% 0.001 0.0001% 0.00 0.0004%

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Table 15: Predicted Concentrations and Percentage of Guideline with Background at Sensitive Receptor 2

Pollutant Averaging

Period

Criteria

(µg/m3)

Background Existing Xyris in Isolation Cumulative -

Normal Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 39 16% 156 64% 63 26% 156 64% 156 64%

Annual Av 62 10 16% 12 19% 10 16% 12 19% 12 19%

SO2

1-hour Max 570 31 5% 31 6% 31 5% 31 6% 31 6%

24-hour Max 228 9 4% 9 4% 9 4% 9 4% 9 4%

Annual Av 60 9 15% 9 15% 9 15% 9 15% 9 15%

CO 8-hour Max 10,000 250 3% 430 4% 260 3% 430 4% 430 4%

PM10 24-hour Max 50 20 40% 22 44% 20 40% 22 44% 22 44%

Annual Av 25 16 64% 16 65% 16 64% 16 65% 16 65%

PM2.5 24-hour Max 25 9 37% 11 46% 9 37% 11 46% 11 46%

Annual Av 8 9 113% 9 113% 9 113% 9 113% 9 113%

Notes:

Annual average background concentrations of PM2.5 are above the guideline before the addition of other regional and XPF sources. This data was obtained from the

Caversham monitoring station located in the Perth Metropolitan Area. Given its rural nature, it is likely that background PM2.5 concentrations will be significantly below

the concentrations presented as background in this table, however they have been included in this assessment for completeness.

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Table 16: Predicted Concentrations and Percentage of Guideline without Background at Sensitive Receptor 4

Pollutant Averaging

Period

Criteria

(µg/m3)

Existing Xyris in Isolation Cumulative - Normal

Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 86 35% 16 7% 86 35% 86 35%

Annual Av 62 0.6 1% 0.1 0.2% 0.7 1% 0.6 1%

SO2

1-hour Max 570 0.09 0.02% 0.01 0.003% 0.09 0.02% 0.09 0.02%

24-hour Max 228 0.006 0.002% 0.01 0.003% 0.01 0.003% 0.01 0.003%

Annual Av 60 0.0005 0.001% 0.0001 0.0002% 0.001 0.001% 0.001 0.001%

CO 8-hour Max 10,000 43 0.4% 7 0.1% 44 0.4% 43 0.4%

PM10 24-hour Max 50 0.5 1% 0.001 0.001% 0.5 1% 0.5 1%

Annual Av 25 0.05 0.2% 0.00001 0.0001% 0.05 0.2% 0.05 0.2%

PM2.5 24-hour Max 25 0.5 2% 0.001 0.002% 0.5 2% 0.5 2%

Annual Av 8 0.05 1% 0.00001 0.0002% 0.05 1% 0.05 1%

Mercury 1-hour Max 2 0.000014 0.0008% 0.00002 0.001% 0.00002 0.001% 0.00004 0.002%

Annual Av 0.2 0.00000012 0.000059% 0.0000002 0.0001% 0.0000003 0.0002% 0.0000006 0.0003%

Benzene 1-hour Max 29 0.05 0.2% 0.3 1% 0.4 1% 2 7%

Annual Av 9.6 0.0005 0.005% 0.003 0.03% 0.004 0.04% 0.02 0.2%

Toluene 1-hour Max 330 0.05 0.02% 0.3 0.1% 0.3 0.1% 2 0.5%

Annual Av 377 0.0004 0.0001% 0.002 0.001% 0.003 0.001% 0.01 0.004%

Ethylbenzene 1-hour Max 7,344 0.01 0.0001% 0.02 0.0003% 0.03 0.0004% 0.1 0.002%

Xylene 1-hour Max 330 0.02 0.01% 0.1 0.03% 0.1 0.04% 0.6 0.2%

Annual Av 868 0.0002 0.00003% 0.001 0.0001% 0.001 0.0001% 0.01 0.0006%

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Table 17: Predicted Concentrations and Percentage of Guideline with Background at Sensitive Receptor 4

Pollutant Averaging

Period

Criteria

(µg/m3)

Background Existing Xyris in Isolation Cumulative -

Normal Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 1-hour Max 246 39 16% 125 51% 55 22% 125 51% 125 51%

Annual Av 62 10 16% 11 17% 10 16% 11 17% 11 17%

SO2

1-hour Max 570 31 5% 31 5% 31 5% 31 5% 31 5%

24-hour Max 228 9 4% 9 4% 9 4% 9 4% 9 4%

Annual Av 60 9 15% 9 15% 9 15% 9 15% 9 15%

CO 8-hour Max 10,000 250 3% 293 3% 257 3% 294 3% 293 3%

PM10 24-hour Max 50 20 40% 21 41% 20 40% 21 41% 21 41%

Annual Av 25 16 64% 16 65% 16 64% 16 65% 16 65%

PM2.5 24-hour Max 25 9 37% 10 39% 9 37% 10 39% 10 39%

Annual Av 8 9 113% 9 113% 9 113% 9 113% 9 113%

Notes:

Annual average background concentrations of PM2.5 are above the guideline before the addition of other regional and XPF sources. This data was obtained from the

Caversham monitoring station located in the Perth Metropolitan Area. Given its rural nature, it is likely that background PM2.5 concentrations will be significantly below

the concentrations presented as background in this table, however they have been included in this assessment for completeness.

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Table 18: Predicted Concentrations and Percentage of Guideline without Background at Onsite Receptor

Pollutant Averaging

Period

Criteria

(µg/m3)

Existing Xyris in Isolation Cumulative - Normal

Operations

Cumulative -

Maintenance Operations

Conc.

(µg/m3) % of Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 15-Minute Max 9400 124 1% 156 2% 156 2% 140 1%

8-Hour Max 5,600 62 1% 78 1% 78 1% 70 1%

SO2 15-Minute Max 13,000 0.2 0.002% 0.5 0.004% 0.5 0.004% 0.4 0.003%

8-Hour Max 5,200 0.1 0.002% 0.3 0.005% 0.3 0.005% 0.2 0.004%

CO 8-Hour Max 34,000 78 0.2% 182 0.5% 182 0.5% 130 0.4%

Mercury 8-Hour Max 25 0.00001 0.00003% 0.0004 0.001% 0.0004 0.001% 0.0004 0.001%

Benzene 8-Hour Max 3,200 0.06 0.002% 6 0.2% 6 0.2% 5 0.2%

Toluene

15-Minute Max 574,000 0.1 0.00002% 9 0.002% 9 0.002% 8 0.001%

8-Hour Max 191,000 0.06 0.00003% 5 0.002% 5 0.002% 4 0.002%

24-Hour Max 3,769 0.01 0.0003% 2 0.06% 2 0.06% 2 0.04%

Ethylbenzene 15-Minute Max 543,000 0.02 0.000004% 0.8 0.0001% 0.8 0.0001% 0.7 0.0001%

8-Hour Max 434,000 0.01 0.000002% 0.4 0.00009% 0.4 0.00009% 0.3 0.00008%

Xylene

15-Minute Max 655,000 0.06 0.00001% 4 0.0005% 4 0.0005% 3 0.0005%

8-Hour Max 350,000 0.03 0.00001% 2 0.0005% 2 0.0005% 2 0.0004%

24-Hour Max 1,085 0.005 0.0005% 0.8 0.08% 0.8 0.08% 0.6 0.06%

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Table 19: Predicted Concentrations and Percentage of Guideline with Background at Onsite Receptor

Pollutant Averaging

Period

Criteria

(µg/m3)

Background Existing Xyris in Isolation Cumulative -

Normal Operations

Cumulative -

Maintenance

Operations

Conc.

(µg/m3)

Conc.

(µg/m3)

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

Conc.

(µg/m3)

% of

Guide.

NO2 15-Minute Max 9400 39 0.4% 163 2% 195 2% 195 2% 179 2%

8-Hour Max 5,600 39 0.7% 101 2% 117 2% 117 2% 109 2%

SO2 15-Minute Max 13,000 31 0.2% 31 0.2% 32 0.2% 32 0.2% 31 0.2%

8-Hour Max 5,200 31 0.6% 31 0.6% 31 0.6% 31 0.6% 31 0.6%

CO 8-Hour Max 34,000 250 0.7% 328 1% 432 1% 432 1% 380 1%

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6. CONCLUSIONS

MEPAU manages the Waitsia Gas Field located on grazing land in the Shire of Irwin, about 19 km

south-east of Dongara and 367 km north of Perth. The Waitsia Gas Project consists of five oil and

gas wells on petroleum permits L1 and L2. The field was discovered in 2014 and has been

developed in stages. The field is currently producing from two wells, Waitsia-01 and Senecio-03.

Wells Waitsia-02, Waitsia-03 and Waitsia-04 wells are currently suspended. Stage 1 of the project

was commissioned in 2016 and achieved an output of ~10 TJ per day. Stage 1 flowed gas from

Waitsia-1 and Senecio-3 gas wells to the XPF owned by MEPAU and delivered treated gas for

domestic use through the PGP.

The Xyris Expansion Project involves increasing production from ~10 TJ per day to 30 TJ per day

– and connecting the facility to the DBNGP (it is currently only connected to the Parmelia Gas

Pipeline). With the capacity increase, emissions to air will increase.

Air dispersion modelling was undertaken to assess the potential air quality impacts of atmospheric

emissions from the proposed expansion of the XPF, comparing the GLCs predicted at sensitive

receptor locations against the relevant ambient air quality criteria.

The modelling indicated that predicted GLCs for most compounds in isolation and cumulatively are

well below the corresponding ambient air quality and workplace exposure standard criteria at the

nominated receptor locations, with the exception of the scenarios that consider annual average

background concentrations of PM2.5.

The annual average background concentrations of PM2.5 were obtained from the Caversham

monitoring station and were already in exceedance of the guideline before consideration of

emissions from other sources. Given the rural nature and lack of industry in the region around the

proposed facility it is highly likely that the actual background concentrations of PM2.5 in the region

are significantly below the monitored concentrations at Caversham. The annual average

concentrations of PM2.5 from XPF and other existing sources predicted without consideration of

background concentrations are only 1% of the guideline.

When considered without potential background concentrations of pollutants, short term impacts

from NO2 were predicted to be the main pollutant of concern from the XPF and MGSF, although

predicted concentrations were still well below the nominated guideline.

The assessment incorporated a number of conservative assumptions, in the absence of more

accurate or representative input data. This means that any uncertainties associated with the

modelling are balanced by the conservativeness of the assessment, and that the outcomes

reported are likely to be over-estimates of the pollutant concentrations that will actually be

experienced at the receptors.

Ramboll - Xyris Production Facility

34/89

7. REFERENCES

Bureau of Meteorology (BOM). 2019. “Climate Data Sites: Site Information”, viewed 28 June 2019,

<http://www.bom.gov.au/jsp/ncc/cdio/cvg/av?p_stn_num=008315&p_prim_element_index=0&p

_display_type=enlarged_map&period_of_avg=&normals_years=&p_comp_element_index=0&redr

aw=null&p_nccObsCode=122>.

Department of Water and Environmental Regulation (DWER). 2018. “2017 Western Australia Air

Monitoring Report Written to comply with the National Environment Protection (Ambient Air Quality)

Measure” July 2018.

Hurley, P. 2008. “TAPM V4. User Manual.” CSIRO Marine and Atmospheric Research Internal Report

No. 5 October 2008.

Hurley, P., Physick, W. and Cope, M. 2004. “Summary of TAPM Verification for the Pilbara Region.”

CSIRO March 2004.

National Environment Protection Council (NEPC). 2011. “National Environmental Protection (Air

Toxics) Measure.” September 2011.

National Environment Protection Council (NEPC). 2015. “National Environmental Protection (Air

Toxics) Measure.” September 2015.

National Environment Protection Council (NEPM). 2013. "National Environmental Protection

(Assessment of Site Contamination) Amendment Measure 2013 (No. 1)". April 2013.

New South Wales Environment Protection Authority (NSW EPA). 2017. “Approved Methods for the

Modelling and Assessment of Air Pollutants in New South Wales.” January 2017.

NPI 2008. Emission estimation technique manual for combustion engines – V. 3.0. Department of

the Environment, Water, Heritage and the Arts, Canberra, ACT.

NPI 2012. Emission estimation technique manual for mining – V. 3.1. Department of

the Environment, Water, Heritage and the Arts, Canberra, ACT.

Queensland Environment Protection Authority (QLD EPA). 2017. "Queensland's Environmental

Protection Air Policy" 2008.

Safe Work Australia. 2018. “Workplace Exposure Standards for Airborne Contaminants” 27 April

2018

Synergetics Environmental Engineering. 2011. “APA Mondarra Emissions Modelling” June 2011

Turner, D.B., 1970. “Workbook of Atmospheric Dispersion Estimates. U.S. EPA Office of Air

Programs Publication No. AP-26. Research Triangle Park, NC.”

World Health Organisation (WHO). 2003. “Concise International Chemical Assessment Document

(CICAD) for Elemental Mercury and Inorganic Mercury Compounds: Human Health Aspects” 2003

Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

P‐WGP1‐023 Rev A  Page 58 of 64 

Attachment 8B – Acoustic Assessment Report (Herring Storer, 2019) 

Rochdale Holdings Pty Ltd A.B.N. 85 009 049 067 trading as: 

HERRING STORER ACOUSTICS P.O. Box 219, Como, W.A. 6952   (08) 9367 6200hsa@hsacoustics.com.au 

RAMBOLL 

XYRIS EXPANSION PROJECT  

ACOUSTIC ASSESSMENT 

MAY 2019 

OUR REFERENCE: 24399‐2‐19051‐02

Herring Storer Acoustics

DOCUMENT CONTROL PAGE 

ACOUSTIC ASSESSMENT XYRIS PROCESSING FACILITY 

Job No: 19051‐02 

Document Reference:  24399‐2‐19051‐02 

FOR 

RAMBOLL 

DOCUMENT INFORMATION 

Author:  Paul Daly  Checked By:  Tim Reynolds 

Date of Issue:  31 May 2019 

REVISION HISTORY 

Revision  Description  Date  Author  Checked 

1  Updated terminology  17/07/2019  PLD 

DOCUMENT DISTRIBUTION 

Copy No.  Version No.  Destination  Hard Copy  Electronic Copy 

1  1 Ramboll Attn : Jeff Barham jbarham@ramboll.com 

1  2 Ramboll Attn : Jeff Barham jbarham@ramboll.com 

Herring Storer Acoustics

CONTENTS 

1. INTRODUCTION 1 

2. SUMMARY 1 

3. CRITERIA 1 

4. MEASURED NOISE LEVELS 3 

5. NOISE MODELING 5 

6. ASSESSMENT 6 

7. CONCLUSION 6 

APPENDICIES 

A  Site Layout/ Reference Locations 

B  Noise Contour Plots 

A  Compressor Data 

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 1

1. INTRODUCTION

Herring Storer Acoustics was commissioned by Ramboll on behalf of Mitsui E&P to undertake anoise assessment relating to noise emissions from the Xyris Production Facility.

The Waitsia gas field began producing natural gas  in August 2016 when the Waitsia Gas ProjectStage 1A was commissioned. Gas is flowed from the Senecio‐03 and Waitsia‐01 wells to the XyrisProduction Facility, which was refurbished in 2016 following a period of care and maintenance, andnow provides an ongoing source of gas to consumers.

To allow for increased capacity, the Xyris production facility is to undergo an expansion. In acousticterms,  this expansion relates to the  introduction of a gas‐powered compressor  into the existingproduction facility.

The purpose of this acoustic assessment is to quantify the existing operational noise levels from thefacility  and,  via  the  use  of  predictive  noise modelling,  calculate  the  inclusion  of  the  proposedcompressor and assess noise levels at the nearest noise sensitive premises.

For information, a locality plan and plant layout is shown in Appendix A.

2. SUMMARY

Assessment of the current and future expansion operations for the Xyris Production Facility shows that compliance at is achieved with the criteria stipulated in the Environmental Protection (Noise)Regulations 1997, for all hours.

3. CRITERIA

The allowable noise level at the surrounding locales is prescribed by the Environmental Protection(Noise) Regulations 1997.  Regulations 7 & 8 stipulate maximum allowable external noise levelsor assigned noise levels that can be received at a premise from another premise. For residentialpremises, the assigned noise  levels are determined by the calculation of an influencing factor,which is then added to the base levels shown below. The influencing factor is calculated for theusage of land within two circles, having radii of 100m and 450m from the premises of concern.For  industrial  and  utility  premises,  the  assigned  noise  levels  are  fixed  for  all  hours.  The  baseassigned noise levels are listed in Table 3.1.

TABLE 3.1 ‐ BASELINE ASSIGNED OUTDOOR NOISE LEVEL 

Premises Receiving Noise 

Time of Day Assigned Level (dB) 

LA10  LA1  LAmax 

Noise sensitive premises  

0700 ‐ 1900 hours Monday to Saturday (Day)  45 + IF  55 + IF  65 + IF 

0900 ‐ 1900 hours Sunday and Public Holidays (Sunday / Public Holiday Day Period) 

40 + IF  50 + IF  65 + IF 

1900 ‐ 2200 hours all days (Evening)  40 + IF  50 + IF  55 + IF 

2200 hours on any day to 0700 hours Monday to Saturday and 0900 hours Sunday and Public Holidays (Night) 

35 + IF  45 + IF  55 + IF 

Industrial and Utility Premises 

All Hours  65  80  90 

Note:  LA10 is the noise level exceeded for 10% of the time. LA1 is the noise level exceeded for 1% of the time. LAmax is the maximum noise level. IF is the influencing factor. 

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 2

It is a requirement that received noise be free of annoying characteristics (tonality, modulation and impulsiveness), defined below as per Regulation 9. 

“impulsiveness”   means  a  variation  in  the  emission  of  a  noise where  the  difference between LApeak and LAmax Slow is more than 15 dB when determined for a single representative event; 

“modulation”   means a variation in the emission of noise that – 

(a) is more than 3dB LA Fast or is more than 3 dB LA Fast in any one‐third octave band;

(b) is  present  for  more  at  least  10%  of  the  representativeassessment period; and

(c) is regular, cyclic and audible;

“tonality”   means  the  presence  in  the  noise  emission  of  tonal  characteristics where the difference between – 

(a) the A‐weighted sound pressure level in any one‐third octaveband; and

(b) the  arithmetic  average  of  the  A‐weighted  sound  pressurelevels in the 2 adjacent one‐third octave bands,

is greater than 3dB when the sound pressure  levels are determined as LAeq,T  levels  where  the  time  period  T  is  greater  than  10%  of  the representative assessment period, or greater than 8 dB at any time when the sound pressure levels are determined as LA Slow levels. 

Where the noise emission is not music, if the above characteristics exist and cannot be practicably removed, then any measured level is adjusted according to Table 3.2 below. 

TABLE 3.2 ‐ ADJUSTMENTS TO MEASURED LEVELS 

Where tonality is present  Where modulation is present  Where impulsiveness is present 

+5 dB(A) +5 dB(A) +10 dB(A)

Note: These adjustments are cumulative to a maximum of 15 dB. 

Based on the distance of the nearest noise receivers, there are no areas considered as industrial or  commercial  land  use,  nor  any major  or  secondary  roads.  Therefore,  the  influencing  factor would be 0 dB. 

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 3

FIGURE 1 – NOISE SENSITIVE RECEIVERS  

Therefore, the assigned noise levels for the nearest noise sensitive premises are contained in Table 3.3. 

TABLE 3.3 ‐ ASSIGNED OUTDOOR NOISE LEVEL 

Premises Receiving Noise 

Time of Day Assigned Level (dB) 

LA10  LA1  LAmax 

Residences A and B 

0700 ‐ 1900 hours Monday to Saturday  45  55  65 

0900 ‐ 1900 hours Sunday and Public Holidays  40  50  65 

1900 ‐ 2200 hours all days  40  50  55 

2200 hours on any day to 0700 hours Monday to Saturday and 0900 hours Sunday and Public Holidays 

35  45  55 

Industrial boundary  All times  65  80  90 

4. MEASURED NOISE LEVELS

To enable the assessment of noise emissions from the current facility, noise level measurementswere carried out on the 21st May 2019.

Noise level measurements at various locations in and around the facility were carried out duringthe site visit. During the measurements, the plant was operated in a representative manner.

Individual noise sources within the plant were identified and measured at close proximity, i.e. 1 to3m to allow for the calculation of sound power levels. All items within the plant were operating,however  only  the  main  contributing  noise  sources  were  used,  with  the  other  items  beingacoustically insignificant.

Xyris Production Facility 

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 4

Overall boundary measurements were also conducted. 

The measurements locations are shown below in Figure 2. 

V 

FIGURE 2 – MONITORING LOCATIONS 

Based on  the  above measurement  locations  and operating  conditions,  Table  4.1  contains  the measured results. 

TABLE 4.1 ‐ MEASURED NOISE LEVELS 

Location  Description  Overall dB(A) 

A  Boundary South  56 

B  Boundary South  65 

C  Boundary South  67 

D  Boundary East  51 

E  Boundary North  55 

F  Boundary North  62 

G  Boundary West  63 

1  Methanol Injection Pumps  93 @ 1m 

2  Generator  78 @ 1m 

3  Low Temperature Separator  88 @ 1m 

ABC

D 

E  F

G

12

3 

N

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 5

5. NOISE MODELING

Noise immissions1 at the nearest neighbouring residential premises, due to noise associated withthe Xyris Production Facility, were modelled with the computer programme SoundPlan. Soundpower levels used for the calculations are based on measured sound pressure levels conductedon site, and for the proposed compressor, the manufacturer noise levels.

The modelling of noise levels has been based on noise sources and sound power levels shown inTable 5.1.

TABLE 5.1 – SOUND POWER LEVEL ‐ NOISE SOURCES dB(A) 

Noise Source   Noise Level  Level Reference 

Low Temperature Separator  97  Lw/unit 

Methanol Injection Pumps  101  Lw/unit 

Generator  86  Lw/unit 

General Pipe Work Noise  75  Lw/m, m² 

Proposed Compressor Engine (100% Load)  116  Lw/unit 

Proposed Compressor Exhaust (100% Load)  84  Lw/unit 

The proposed compressor is a CAT G3512B Gas Engine with an Ariel compressor unit fitted. The engine is not enclosed; however the exhaust system has a “Hospital Pack” silencer fitted reducing the noise level to 75 dB(A) at 1 metre. All noise modelling was based on data for the unit operating at 100% load. Appendix C contains the manufacturer data for the proposed compressor unit. 

Based on noise emissions2 from the above equipment, the following operating scenarios were developed: 

S1  Existing Production Facility. S2  Existing Production Facility with the new compressor. 

The predictive noise model was calibrated to the measurement locations as shown in Figure 2. Allowance was made for the influence of background noise. 

The following input data was used in the calculations: 

a) Provided site layouts.b) Sound Power Levels listed in Table 5.c) Ground contours and receiver points provided by client.

1 Immissions – noise received at a source 2 Emissions – noise emanating from a source and / or location

Herring Storer Acoustics Our ref: 24399‐2‐19051‐02 6

Weather conditions for modelling were as stipulated in the Environmental Protection Authority’s “Draft Guidance for Assessment of Environmental Factors No. 8 ‐ Environmental Noise” as listed in Table 5.2. 

TABLE 5.2 – WEATHER CONDITIONS 

Condition  Night  Day 

Temperature  15°C  20°C 

Relative humidity  50%  50% 

Pasquill Stability Class  F  E 

Wind speed  3 m/s*  4 m/s* 

* From sources, towards receivers. 

It  is  noted  that  ‘worst  case’  wind  conditions  refer  to  conditions where  there  is  a  temperature inversion in conjunction with light winds in the direction from noise source to receiver, resulting in effective sound propagation towards receiver locations. 

6. ASSESSMENT

Calculated noise levels associated with the noise emissions from the operating Xyris ProductionFacility  for  the various scenarios are summarised below  in Table 6.1. Appendix B contains  thenoise contour plots.

TABLE 6.1 – CALCULATED NOISE LEVEL (LA10) 

Receiver Scenario 1  Scenario 2 

Existing Xyris Facility  Future Expansion Xyris Facility 

A  <10  14 

B  <10  15 

The above noise levels are considered to not contain tonal characteristics, due to the ambient noise. 

Hence,  Table  6.2  summarises  assessable  noise  level  emissions,  for  the worst  case  night‐time scenario considered being all equipment in the production plant operating at the same time.  

TABLE 6.2 – ASSESSMENT OF BITUTEK OPERATIONS LA10 NOISE LEVELS 

Premises Receiving Noise 

Future Expansion Time of Day 

Assigned Level (dB)  Compliance LA 10 

A  14  2200 hours on any day to 0700 hours Monday to Saturday and 0900 hours Sunday and Public Holidays (Night) 

35 Complies 

B  15  Complies

7. CONCLUSION

Assessment  of  the  current  and  future  operations  for  the  Xyris  Production  Facility  shows  thatcompliance  at  the  residential  locations  is  achieved  with  the  criteria  stipulated  in  theEnvironmental Protection (Noise) Regulations 1997, for all hours of operations.

APPENDIX A 

LOCATION MAP / PLANT LAYOUT

                                  

Xyris Production Facility 

APPENDIX B 

NOISE CONTOUR PLOTS 

APPENDIX C 

COMPRESSOR DATA 

Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

P‐WGP1‐023 Rev A  Page 59 of 64 

Attachment 8C – Environmental Commissioning Management Plan 

PERTH 7/50 Oxford Close West Leederville WA 6007 Phone 08 6229 6500

BRISBANE 2/15 Heather Street Wilston QLD 4051 Phone 07 3856 2447

DEVELOPMENT | ENGINEERING | MANAGEMENT | COMPLETIONS

WAITSIA STAGE 1 EXPANSION PROJECT

ENVIRONMENTAL COMMISSIONING MANAGEMENT PLAN

Doc. No: Pending Rev: A

DOCUMENT REVISION HISTORY

Rev Date Issue Orig Chk App Client

A 10/09/2019 Issued for Review GRW CJS CJS

This document has been prepared by Enscope for the exclusive use by AWE Perth. The document must not be distributed to or used by any third party without the express written permission of Enscope and is subject to the provisions of the agreement between Enscope and AWE Perth. Enscope accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this document by any third party.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 2 of 18

TABLE OF CONTENTS

1  COMMISSIONING ................................................................................................................................. 4 

1.1  Commissioning Scope ................................................................................................................. 4 

1.1.1  Construction & Handover ..................................................................................................................... 4 

1.1.2  Pre-Commissioning .............................................................................................................................. 4 

1.1.3  Gas Commissioning ............................................................................................................................. 5 

1.1.4  Operations ............................................................................................................................................ 6 

1.2  Management & Monitoring ........................................................................................................... 6 

1.2.1  Emissions & Discharges ...................................................................................................................... 6 

1.2.2  First Fills and Introduction of Hydrocarbons Management .................................................................. 9 

1.3  Enviornmental Targets & Limits ................................................................................................. 17 1.4  Contingencies ............................................................................................................................ 17 1.5  Management of Malfunctions ..................................................................................................... 17 1.6  Reporting ................................................................................................................................... 17 1.7  Commissioning Report .............................................................................................................. 17 1.8  Responsibilities .......................................................................................................................... 18 

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 3 of 18

Holds

Number Section Reference Details

 WAITSIA STAGE 1 EXPANSION

ENVIRONMENTAL COMMISSIONING MANAGEMENT PLAN

 

 

 

Document No: N/A Waitsia Stage 1 Expansion

Revision: A Page 4 of 18

 

1 COMMISSIONING

1.1 COMMISSIONING SCOPE

Following completion of construction activities, commissioning activities will commence over a period of six weeks.

The scope of the commissioning works to be completed and managed by the EPCM Contractor includes the following facilities and locations:

All new facilities, flowlines and pipelines including:

o Waitsia-02 wellhead facility, above ground flowline & tie-in compound.

o Waitsia Export Pipeline & pig receiver compound.

The modified Xyris Production Facility.

The modified Waitsia-02 evaporation pond.

At each of the above sites, as applicable, the scope of the commission works to be completed and managed by the EPCM Contractor includes the following activities:

Construction completions and handover from the construction contractors to the commissioning team.

Pre-commissioning of all aspects of the works.

First introduction of gas from the reservoirs through to the isolation valve to the AGIG DBNGP Metering Compound at the battery limit of the Waitsia Export Pipeline.

Gas commissioning of all aspects of the works including testing and tuning of the system.

First start-up and first commercial gas flows.

Operator training.

Handover to operations.

1.1.1 CONSTRUCTION & HANDOVER

All construction activities and management up until the point of handover to commissioning will be in accordance with the requirements detailed in the Construction Management Plan (XYR-EXP-TG-056).

As detailed in the DMIRS approved Construction Safety Case documents, control, authority and responsibility of the facilities has been formally handed over to the EPCM Contractor for completing the construction, construction completions and pre-commissioning activities. Works during construction will be completed under the approved Area Work Clearance Procedure (XYR-EXP-TH-010) and Permit to Work Procedure (XYR-EXP-TH-011) in the greenfields areas noting the presence of specific brownfields areas which are subject to further Company Permit to Work requirements.

1.1.2 PRE-COMMISSIONING

As facilities or parts of facilities are handed over to commissioning, the applicable areas will be demarcated by blue flagging as an area under Commissioning control where only personnel who have completed the commissioning induction are permitted access.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 5 of 18

All pre-commissioning activities will be completed under the applicable DMIRS approved Construction Safety Case documents and Construction Environmental Plans:

Waitsia Stage 1 Expansion Project: Construction Safety Case – Pipeline & Facilities (PB-HSE-PLN-006-ADD-004)

Waitsia Stage 1 Expansion Project: Pipeline Construction Environment Plan (P-WGP1-019)

Waitsia Stage 1 Expansion Project: Facilities Construction Environment Plan (P-WGP1-018)

Further, all construction completions and pre-commissioning activities will be completed under the following project documents:

Commissioning Management Plan (XYR-EXP-TG-057).

Project Health & Safety Management Plan (XYR-EXP-TG-049).

Project Environmental Management Plan (XYR-EXP-TG-050).

Construction Emergency Response Plan (XYR-EXP-TH-021).

Area Work Clearance Procedure (XYR-EXP-TH-010).

Permit to Work Procedure (XYR-EXP-TH-011).

1.1.3 GAS COMMISSIONING

Upon completion of all pre-commissioning works and receipt of Approval to Operate from the DMIRS, a transfer process will be completed whereby control and authority over the facilities will be handed over to the Company’s operations team. After the handover, all activities will be completed under the applicable DMIRS approved Operation Safety Case documents and the Operations Environmental Management Plans:

Perth Basin Pipeline Operations Safety Case (PB-HSE-PLN-006).

Perth Basin Operations Safety Case Addendum – Waitsia Stage 1 Expansion Project (ConstructionOperations) (PB-HSE-PLN-006-ADD-004)

Perth Basin Facilities Environment Plan (PB-HSE-PLN-004) (covers operations and maintenanceactivities).

Further, all gas commissioning and site activities will be completed under the following documents:

Commissioning Management Plan (XYR-EXP-TG-057).

Commissioning Health & Safety Management Bridging Plan (XYR-EXP-TH-023).

Perth Basin Facilities Environment Plan (PB-HSE-PLN-004).

Commissioning Emergency Response Bridging Plan (XYR-EXP-TH-024).

Area Work Clearance Procedure (XYR-EXP-TH-010).

Permit to Work Procedure (XYR-EXP-TH-011).

Although control and authority of the sites will be handed over to the Company for Gas Commissioning, management of site will remain the responsibility of the EPCM Contractor.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 6 of 18

1.1.4 OPERATIONS

Upon completion of all gas commissioning works, a handover process will be completed whereby the Company’s operations team will accept the completed facility and take over management of the facilities in accordance with their approved operating documents.

1.2 MANAGEMENT & MONITORING

Subsequent to the Construction phase of the Project, Completions, Commissioning and Handover will take place, employing a much reduced workforce, plant, vehicle and equipment requirement than the Construction phase, albeit the introduction of first-fills (methanol, oils, lubricants, etc), hydrocarbon and production of water and liquids at plant start-up, all of which pose a threat to the Environment.

A Commissioning and Handover phase Environmental Risk Assessment will be conducted to identify all environmental threats that could be posed by the Commissioning and Handover works to be completed for the Project and include a description of the mitigation measures to be employed to prevent environmental harm during this phase of the Project.

Environmental issues and management directions relevant to all specific Commissioning and Handover related environmental threats will be incorporated into Procedures, SWMS’s, JHA’s and ITP's for the Commissioning and Handover work activities, providing clear direction on the activity to be undertaken. SWMS's / JHA’s are reviewed and signed off by the respective crews. The activity specific ITP is issued to Supervisors and includes any constraints or guidelines to follow in undertaking that activity.

1.2.1 EMISSIONS & DISCHARGES

Daily visual inspections onsite will continue to be undertaken by EPCM Contractor personnel.

Dust will be assessed on a daily basis during commissioning by the Commissioning Manager who will observe dust conditions. If excessive dust generation is observed, the source will be investigated and remedial actions implemented as required.

Dust monitoring will occur as per the existing DWER Licence ((L7847/2003/7). This includes ensuring that all reasonable and practicable measures are used to prevent or minimise dust emissions and that no visible dust generated by activities on the Premises crosses the boundary of the Premises.

Noise Modelling indicates noise limits will be in accordance with the Environmental Protection (Noise) Regulations 1997. The risk to personnel due to the potential exposure to noise during commissioning will be managed in accordance with the occupational health and safety systems and procedures detailed in the Perth Basin Operations Safety Case [PB-HSE-PLN-006].

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 7 of 18

Table 1.2.1 Emissions & Discharges During Commissioning

Aspect Monitoring Frequency

Monitoring Methodology

Calibration Details Methodology Justification

Quantification

Volume of PFW discharged to the

Waitsia-02 evaporation pond

Weekly Via flow meter Calibration certificate

Provides a manual means

of measurement

of PFW volume

168,000L

Volume of PFW discharged to the

Hovea evaporation pond (only used in the

event the Waitsia-02 pond is unavailable)

On load-out Road Tanker Volume

Visual check against tanker

prior to and post load out

Provides a manual means

of measurement

of PFW volume

0L

PFW Free Hydrocarbon Concentration

Weekly inspections

Automated level control in tank prevents free

hydrocarbon phase in storage tank

from being discharged to pond

Visual observation of PFW discharged

to pond

Level Controls calibration certificate

Provides automatic and manual means

of managing the free

hydrocarbon content in PFW

Less than 100ppm total hydrocarbon

concentration in PFW.

Free hydrocarbon that may collect

on the pond surface are removed by

skimming as part of weekly

inspections.

Hydrocarbon gas vented

Monthly Estimated based on gas production

and individual venting events

Export meter calibrated monthly

and records of manual venting

Provides data required for

NGER Method 1 emissions estimation

11,000kg

Fuel Gas Monthly Via fuel gas flow meter

Power generation and gas

compression check against fuel

consumption

Provides data required for

NGER Method 1 emissions estimation

64,000kg of exhaust gas emissions

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 8 of 18

Diesel for Stationary engines

Monthly Volume of diesel consumed

- Method used for

Commonwealth Diesel Fuel

Rebate Applications

2,000L

Waste disposed At time of disposal

Vendor receipt / waste receptacle

count

- Bins are fixed size enabling

estimation of m3 waste

10m3

GEA stack emissions

Nil Via runtime - - 1,600tons

Compressor package stack

emissions

Nil Via runtime - - 1,470tons

These parameters are also intended to be monitored by the Company during operations.

Management of general environmental issues identified for the Commissioning phase is provided in the following section.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 9 of 18

1.2.2 FIRST FILLS AND INTRODUCTION OF HYDROCARBONS MANAGEMENT

First Fills and Introduction of Hydrocarbons Management Environmental Impacts

Damage to surrounding land, third party assets and habitats from fire. Contamination to land and water from uncontained chemical, hydrocarbon and / or fuel spills. Contamination of air quality and / or community impacts due to venting of hydrocarbons Community impacts from fire or uncontained chemical, fuel or hydrocarbon spills.

Environmental Performance Objectives and Performance Standards

To have zero fire events resulting from commissioning and handover. To provide that all venting and liquid draining is controlled in accord with approved Project procedures and all relevant protection measures are in place for the same. To protect human health and the environment from exposure to hazardous substances.

Measurement Criteria

Compliance with AS1940 for storage and handling of fuels and chemicals. Compliance with SDS for fuels and chemicals. Compliance with fire, fuel and chemical management measures. Compliance with isolations, controlled venting and controlled purging / draining activities

Management Measures

Action Monitoring / Inspection / Audit Responsibility

Physical Action Responsibility

Fire Management

Fire Precautions

1. Regular contact will be made with DFES for any works required where a total fire ban orany fire restriction is in place.

Commissioning Manager

HSE Advisor

2. Approval for hot works during periods of total fire ban will be in place via the Company.Should works be required on a day of total fire ban or fire restriction, the HSE Advisor shallensure DFES are advised and confirm the suitability for works to continue and satisfy him

Commissioning Manager

HSE Advisor to confirm DFES

 WAITSIA STAGE 1 EXPANSION

ENVIRONMENTAL COMMISSIONING MANAGEMENT PLAN

 

 

 

Document No: N/A Waitsia Stage 1 Expansion

Revision: A Page 10 of 18

 

First Fills and Introduction of Hydrocarbons Management / herself that the requirements of the Company’s permit are in place (at a minimum) at each hot work location intending to perform works on such days.

approve works on such days. Contractors assisting the Commissioning and Handover to ensure they can meet the minimum requirements of the DFES permit.

3. Spark arrestor shields will be used during grinding activities. Appropriate fire-fighting equipment will be carried with the welding crews at all times and personnel trained in its use.

Commissioning Manager

Contractor Supervisors

4. Precautions will be taken to prevent the ignition of fire during welding operations, including:

Hot Works Permit in place as Site will be considered brownfields during Commissioning and Handover phase

there will be no combustible material in close proximity to welding or butt fusion activities;

appropriate fire-fighting equipment will be carried with any crews permitted to perform hot works and personnel trained in its use;

No venting / draining of hydrocarbon in the vicinity of hot works

Commissioning Manager

Company PIC to issue Hot Works Permit Contractor Supervisors to ensure conditions are met

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 11 of 18

First Fills and Introduction of Hydrocarbons Management EPCM Commissioning Team (ECT)

5. Fire-fighting equipment will be present wherever flammable chemicals are stored.Incompatible chemicals will not be stored together.

Commissioning Manager

Contractor Supervisors

ECT 6. Work areas will be managed to avoid the build-up of vegetation or other flammable

material.Commissioning Manager

Contractor Supervisors

ECT 7. No billy fires or similar, or other unapproved open flames, will be lit / used on the Project

area.Commissioning Manager

Contractor Supervisors

ECT 8. The construction worksite is a limited smoking workplace. This means that smoking is only

allowed in designated areas. Smoking in areas such as offices, crib rooms, vehicles,workshops and toilets is prohibited. Smoking on site (open air) is restricted to those areaswhere it is safe to do so and where non-smoking personnel will not be affected.

Commissioning Manager HSE Advisor

Contractor Supervisors

ECT

9. Operational restrictions arising from the declaration of Total Fire Ban days will becommunicated via pre-starts and toolbox talks.

Commissioning Manager

Contractor Supervisors

ECT

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 12 of 18

Vehicles and Machinery

10. Diesel fuelled vehicles and machinery will be used preferentially for the Commissioningphase. All vehicles used in brownfields works will be fitted with spark arresters.

Commissioning Manager

Contractor Supervisors

ECT 11. Machinery will be regularly maintained to minimise the risk of fuel and oil leaks. This will

include cleaning / removal of surplus oils, oil impregnated dust and vegetation matter toreduce fire risks.

Commissioning Manager

Contractor Supervisors

ECT 12. Defective equipment / machinery will be shut down, and tagged out, until the defect has

been rectified.Commissioning Manager

Contractor Supervisors

ECT 13. All machinery will carry a serviceable fire extinguisher. Commissioning

Manager Contractor Supervisors

ECT Fuel and Chemical Management

General

14. The storage and handling of fuels and chemicals will comply with all relevant legislationand Australian Standards (AS 1940: 2017).

HSE Advisor Contractor Supervisors

ECT 15. All fuels and chemicals on the Project site will be clearly identified. A site manifest including

SDS’s will be maintained at the site office and at any other relevant locations.HSE Advisor Contractor

Supervisors to provide input to

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 13 of 18

master Site SDS Register

HSE Advisor to compile and maintain the Master Site SDS Register

16. Chemical use will be minimised consistent with safe / efficient construction requirements,and the minimum practicable volume will be kept on site.

HSE Advisor Contractor Supervisors

ECT 17. Chemicals which pose lower risk to personnel and the environment will be chosen over

those associated with higher risk, where viable alternatives are available and ofcomparable effectiveness.

HSE Advisor Contractor Supervisors

ECT 18. Workforce training will be conducted in fuel and chemical handling and spill response and

recovery procedures. Training will be targeted at members of the workforce or routinelyhandling chemicals.

HSE Advisor Contractor personnel and EPCM personnel as identified by the Construction Manager

19. A Commissioning Emergency Response Bridging Plan (XYR-EXP-TH-024) will be in placeand personnel inducted in its application.

HSE Advisor All personnel

Fuel and Chemical Storage

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 14 of 18

20. Fuels and chemicals will be stored separated within containment facilities and handled toreduce the risk of spills. Storage tanks must be bunded so that the capacity of the bund issufficient to contain 110% of a single storage tank or 100% of the largest storage tank plus10% of the second largest storage tank.

HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT 21. Drum storages (sites less than 500 litres capacity) will be bunded so that the capacity and

construction of the bund is sufficient to contain at least 25% of the maximum design storagevolume within the drum. Bunding will be impervious.

HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT 22. Bulk Fuels (3,500 litres or greater) will not be stored on the Project Site. HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT 23. The ROW will not be used for the storage of chemicals. Chemicals stored on site (at Facility

Sites only) will be bunded as described above.HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT 24. Absorbent and containment material (e.g. absorbent matting) will be available where bulk

fuels and hazardous materials are stored, used and decanted / refuelled – includingrefuelling pumps and larger generators – and personnel trained in correct use.

HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT Fuel Management / Refuelling

25. Re-fuelling of plant, vehicles and equipment at Site will aim to reduce the overnight storagequantity in any individual fuel tank so as to mitigate the temptation for theft events or anyspill in the event of targeted vandalism.

HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT 26. Spill kits will be kept in the vicinity of all storage tanks and to minimise response time in the

event of any spill.HSE Advisor

Commissioning Manager

Contractor Supervisors

ECT

 WAITSIA STAGE 1 EXPANSION

ENVIRONMENTAL COMMISSIONING MANAGEMENT PLAN

 

 

 

Document No: N/A Waitsia Stage 1 Expansion

Revision: A Page 15 of 18

 

Waste Disposal and Contaminated Land

27. Waste lubricants, contaminated soil and any other oily wastes will be contained, bunded and disposed of at an approved disposal facility. Records of prescribed industrial waste transport and disposal will be maintained in accordance with regulatory requirements.

HSE Advisor Commissioning Manager

Contractor Supervisors ECT

28. Produced water will be stored in the Produced Water Tank and exported to the Waitsia-02 evaporation pond via HDPE piping, or to the Hovea Production Facility via vacuum tanker. Records of produced water and disposal will be maintained in accordance with any regulatory requirements.

HSE Advisor Commissioning Manager

Contractor Supervisors ECT

29. Produced condensate will be stored in the Liquids Stock Tank and exported to the Dongara Production Facility via vacuum tanker for later disposal at an approved disposal facility. Records of prescribed industrial waste transport and disposal will be maintained in accordance with regulatory requirements.

HSE Advisor Commissioning Manager

Contractor Supervisors ECT

Compliance Monitoring

During commissioning, the Project Site shall be formally inspected weekly by the Commissioning Manager. The scope of these inspections will include:

inspection of storage, handling and use of chemicals at site office and along the Construction Right of Way; inspection of suitable use of isolation methods to prevent spills; inspection of any minor fuel storage at Site, including bunding; inspection of refuelling practices; inspection of bunds for drum storages and portable pumps / equipment; inspection of Waitsia-02 evaporation pond levels; inspection of availability and effectiveness of spill kits; and inspection of availability and effectiveness of fire extinguishers.

Non-compliance, hazard and incident reporting will be implemented in accordance with the Construction Environmental Management Plan (XYR-EXP-TG-050). Any landowner complaints will be notified to the Company and appropriate corrective actions implemented including a review of work practices to ensure no repeat occurrences.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 16 of 18

Audits in accordance with the Construction Environmental Management Plan (XYR-EXP-TG-050) will be undertaken and recommendations and corrective actions shall be implemented.

Records Site Training Matrix (includes Induction record) Completed Environmental Inspection Checklists (weekly) Weed Hygiene Inspection Log Complaints Register (To be developed if complaints arise) Area Works Clearance Form Permit to Work Form Company Permit to Work Site Master SDS Register Plant and equipment maintenance records

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 17 of 18

1.3 ENVIORNMENTAL TARGETS & LIMITS

The EPCM Contractor will target complete containment of all discharges to land within the Site disturbance footprint.

Noise limits will not exceed the requirements of the Company’s Noise Regulations.

The EPCM Contractor will target no visible particulate emissions being observed during commissioning, and if identified (i.e. at the equipment exhausts and vents) commissioning activities will cease until the source is identified and the fault rectified.

1.4 CONTINGENCIES

Should any of the proposed target values be exceeded, commissioning activities will continue as planned whilst a formal investigation is undertaken.

Should any of the limit values be exceeded under normal operating conditions, commissioning activities will immediately cease whilst investigations are being carried out

1.5 MANAGEMENT OF MALFUNCTIONS

During the commissioning phase, malfunction of equipment may occur. If a failure occurs, then the system will be shut down until the fault is rectified.

1.6 REPORTING

All incidents will be recorded and investigated under an internal incident reporting system in place at the Project. Reporting of incidents other than minor incidents shall follow the requirements set out in s72 of the Environmental Protection Act 1986.

Should any of the targets (stated above) be exceeded during commissioning with the possibility that the targets may need to be amended, the EPCM Contractor will provide the DWER (via the Company) with the following information:

The non-conforming emission / discharge and extent to which the target value was exceeded.

Management responses to the exceedance and their effect on the emission / discharge.

An explanation as to why the exceedance may have occurred and any corrective actions taken tominimise the risk of a re-occurrence.

1.7 COMMISSIONING REPORT

Upon completion of commissioning activities, a Commissioning Report will be submitted to the DWER as soon as possible after completion of the gas commissioning program.

WAITSIA STAGE 1 EXPANSION ENVIRONMENTAL COMMISSIONING

MANAGEMENT PLAN

Document No: N/A Waitsia Stage 1 Expansion Revision: A Page 18 of 18

1.8 RESPONSIBILITIES

To ensure that the commissioning plan is appropriately implemented the following responsibilities have been assigned in relation to key tasks and commitments.

Table 1.8.1 Environmental Commissioning Management Plan Key Task & Commitment Responsibilities

Task / Commitment Responsible Person

Undertake visual inspections of the facilities Refer section 1.2.2

Undertake the required monitoring Refer section 1.2.2

Implement contingency actions in accordance with Commissioning Management Plan & Emergency Response Plan

Commissioning Manager

Report any emission exceedances to the DWER Commissioning Manager (via the Company Representative)

Undertake reporting commitments in accordance with Commissioning Management Plan

Commissioning Manager

Submit a Commissioning Report to the DWER summarising relevant monitoring data and management upon completion of commissioning (as required by Licence amendment conditions when issued)

Commissioning Manager (via the Company Representative)

Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

P‐WGP1‐023 Rev A  Page 60 of 64 

Attachment 8D – Process Flow Diagrams and Site Layout at XPF and Waitsia‐02 Wellhead 

PeterDowse

Pen

PeterDowse

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PeterDowse

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Waitsia Stage 1 Expansion Project ‐ Works Approval Application Supporting Documentation 

P‐WGP1‐023 Rev A  Page 61 of 64 

Attachment  8E  –  Waitsia  Stage  1  Expansion  Project:  Construction  Oil  Spill Contingency Plan 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page ii  

REVIEW FREQUENCY 

Next Revision Date  Revision Cycle 

16/04/2022  2.5 Years 

DISTRIBUTION 

All controlled documentation  is uploaded and managed  in the MEPAU Perth Basin Operations Document Management System (DMS) SharePoint. Reader should access  the DMS to ensure  latest version  is always referenced. DMS Link: https://mepau.sharepoint.com/Operations   

Distribution outside of the SharePoint DMS is to the discretion of the document author / owner.  

Disclaimer: 

This document is protected by copyright, no part of this document may be reproduced or adapted without the consent of the originator/company owner, all rights are reserved. This document is “uncontrolled when printed”, refer to electronic copy for up to date version. 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page iii  

Contents

1.0  INITIAL RESPONSE ACTIONS ............................................................................................................. 1 

2.0  INTRODUCTION ................................................................................................................................ 4 

2.1  BACKGROUND .......................................................................................................................................... 4 

2.2  SCOPE ..................................................................................................................................................... 4 

2.3  GEOGRAPHICAL AREA ................................................................................................................................ 4 

2.4  DESCRIPTION OF THE ENVIRONMENT ........................................................................................................... 4 

2.5  DESCRIPTION OF ACTIVITIES ........................................................................................................................ 8 

2.6  ASSOCIATED DOCUMENTS .......................................................................................................................... 8 

2.7  OSCP REVIEW .......................................................................................................................................... 8 

3.0  CREDIBLE SPILL SCENARIO’S ............................................................................................................. 9 

4.0  OIL SPILL RESPONSE PREPAREDNESS .............................................................................................. 10 

4.1  TIERED RESPONSE TO CREDIBLE OIL SPILL SCENARIOS ................................................................................... 10 

4.2  TERMINATION OF RESPONSE ..................................................................................................................... 10 

4.3  RESPONSE EQUIPMENT / RESOURCES ......................................................................................................... 10 

4.4  PERSONNEL ........................................................................................................................................... 11 

4.5  TESTING ................................................................................................................................................ 11 

5.0  STRUCTURE, ROLES AND RESPONSIBILITIES .................................................................................... 12 

5.1  EMT ACTIVATION ................................................................................................................................... 12 

5.2  ROLES AND RESPONSIBILITIES .................................................................................................................... 12 

5.3  TRAINING .............................................................................................................................................. 13 

5.4  CONTACT DIRECTORY .............................................................................................................................. 13 

6.0  SPILL RECOVERY, WASTE MANAGEMENT AND COST RECOVERY ..................................................... 14 

6.1  SPILL RECOVERY METHOD ........................................................................................................................ 14 

6.2  MONITORING ......................................................................................................................................... 14 

6.3  WASTE MANAGEMENT ............................................................................................................................ 14 

6.4  OILED WILDLIFE RESPONSE ...................................................................................................................... 15 

6.5  COST RECOVERY ..................................................................................................................................... 15 

6.6  REPORTING REQUIREMENTS ..................................................................................................................... 15 

APPENDIX A  MEPAU EMERGENCY CONTACT DIRECTORY ..................................................................... 16 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page iv  

LIST OF FIGURES 

Figure 1‐1: Emergency Management Team Activation and Spill Response Process Flow ................................. 2 

Figure 2‐1: Waitsia Gas Project (Production Licence L1) and Operational Area for this EP .............................. 6 

Figure 2‐2: Conservation Significant Areas ........................................................................................................ 7 

Figure 2‐3: Hierarchy of Systems, Practices and Procedures ............................................................................. 8 

Figure 5‐1: EMT / ERT Organisation ................................................................................................................. 12 

LIST OF TABLES 

Table 1‐1: Initial Response Actions .................................................................................................................... 3 

Table 2‐1: OSCP Associated Documents ............................................................................................................ 8 

Table 3‐1: Spill Scenario Information ................................................................................................................. 9 

Table 4‐1: Spill Scenario Information ............................................................................................................... 10 

Table 4‐2: Response Termination Criteria ....................................................................................................... 10 

Table 5‐1: Summary of OSCP Roles and Responsibilities ................................................................................. 13 

Table 6‐1: List of Recovery Methods ................................................................................................................ 14 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page v  

TERMS, ABBREVIATIONS AND DEFINITIONS 

Term or abbreviation  Definition 

CMT  Crisis Management Team 

DBCA  Department of Biodiversity, Conservation and Attractions 

DBNGP  Dampier Bunbury Natural Gas Pipeline 

DMIRS  Department of Mines, Industry Regulation and Safety 

EMT  Emergency Management Team 

ERP  Emergency Response Plan 

ERT  Emergency Response Team 

ESA  Environmentally Sensitive Area 

GDE  Groundwater Dependent Ecosystem 

MEPAU  Mitsui E&P Australia  

OSC  On‐Scene Commander 

OSCP  Oil Spill Contingency Plan 

PGER(E)R  Petroleum and Geothermal Energy Resources (Environment) Regulations 

PP(E)R  Petroleum Pipelines (Environment) Regulations 

PGP  Parmelia Gas Pipeline 

SDS  Safety Data Sheet 

TJ  Terajoule 

WA  Western Australia  

WIA OSCP  Well Intervention Activity Oil Spill Contingency Plan 

WS1E  Waitsia Stage 1 Expansion Project 

XPF  Xyris Production Facility 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page 1  

1.0 INITIAL RESPONSE ACTIONS 

In  the  event  of  a  spill,  the  identifier  or  observer  of  the  spill  is  required  to  report  the  event  to  the Construction Manager. Once notified, and subject to assessment and determination of the Emergency Level of the spill, the Contractor’s Construction Manager becomes the On‐Scene Commander (OSC) in accordance with this Oil Spill Contingency Plan (OSCP) and the Emergency Response Plan (ERP). For Level 2 or 3 incidents, the MEPAU Site Representative / Person in Charge (PIC) will take over the OSC position, however the Construction Manager will take the lead role in the initial response to all incidents.  

An overview of MEPAU’s Emergency Response Organisational structure is provided in Section 5.0. 

The protection priorities in the event of a spill in order of importance are:  

PEOPLE ‐ Preserve life and ensure the safety of people; 

ENVIRONMENT‐ Minimise impacts on the environment and the community; 

ASSETS ‐ Minimise impacts on property or assets; 

REPUTATION ‐ Minimise impacts on the business, other organisations and the MEPAU image by: 

Protecting continuity of operations;

Minimising commercial interruption, losses and legal liabilities; and

Maintaining and, where possible, enhancing MEPAU’s image and reputation.

The flow chart in Figure 1‐1 summarises the process for: 

Activating the Emergency Response Team (ERT) and Emergency Management Team (EMT),

Determining environmental reporting requirements, and

Determining which initial response actions to implement in the event of a spill on‐site.

In the event of a spill event, initial response actions should be implemented in accordance with Table 1‐1. 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

P‐WGP1‐020 Rev 0  Page 2  

Figure 1‐1: Emergency Management Team Activation and Spill Response Process Flow 

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Table 1‐1: Initial Response Actions 

Response Actions  Role  Done 

1  Notify the Contractor’s Construction Manager and MEPAU Site‐representative Initial Observer

2  Assess situation and determine if and what emergency services are required – contact them in accordance with Section 5.4 

of this Plan 

On‐Scene Commander (OSC) 

3  Assess the risk of fire and explosion. If safe, attempt to stop or stem flow of hydrocarbons. OSC  

4  If the event is classified as a Loss of Well Control Event – Refer to the Well Intervention Activity Oil Spill Contingency Plan 

[HSE‐OP‐030] for further information.  

OSC 

5  Determine Emergency Level (Section 4.1)  OSC

5a  If the event is considered to be a Level 1 – Incident notify the Project Manager and call out the ERT (where the 

event is significant enough to require it) 

OSC 

5b  If the event is considered to be a Level 2 – Emergency or greater notify the EMT and refer to MEPAU’s Perth Basin 

Operations ERP [PB‐HSE‐PLN‐007]. 

OSC  

6  Collect portable spill equipment bins and use them at the spill site to contain spillage where possible /safe to do so.  OSC 

7  Consider development of earthen bunds to contain spill to hardstand where appropriate  OSC

8  Verify if the area hydrocarbon contaminated material is greater than500 L or 100 m2. Where the spill volume is greater than 

500 L or the area is greater than 100 m2 notify MEPAU Senior Environmental Advisor  

OSC 

9  Where the spill volume is greater than 500 L or the area is greater than 100 m2 notify the Department of Mines, Industry 

Regulation and Safety (DMIRS) Petroleum Environmental Duty Officer on 0419 960 621 and commence reportable incident 

reporting (initial notification required within 2 hours of the spill event). For specific information (including contact details 

refer to Table 6‐5 of the EP. 

MEPAU Senior Environmental 

Advisor 

10  Once the site is safe, the situation is no longer deemed an emergency, and in accordance with the relevant SDS, commence 

recovery and removal of hydrocarbons and contaminated soil from spill site  

MEPAU Site‐representative 

11  Commence soil / groundwater sampling where directed by the Environmental Advisor (this is dependent on the type of spill 

event) 

MEPAU Site‐representative 

12  Once site contamination is no longer a concern commence backfill operations.  MEPAU Site‐representative 

13  Supervise completion of spill site clean‐up, reinstate fencing (if applicable) and repair road damage.  MEPAU Site‐representative

14  Notify external resources in Perth and resources on site of termination of the response.  MEPAU Site‐representative 

15  Commence incident investigation procedures  MEPAU Site‐representative 

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2.0 INTRODUCTION 

2.1 Background  

AWE Perth Pty Ltd (AWE) is the project proponent for the Waitsia Stage 1 Expansion (WS1E) Project. AWE and Mitsui E&P Australia Pty Ltd are wholly owned subsidiaries of Mitsui & Co. Ltd., and combined they form the unified brand Mitsui E&P Australia (MEPAU). 

MEPAU is the Operator of the Waitsia gas field within the onshore North Perth Basin located within the Shire of Irwin, approx. 20 km southeast of Dongara and approx. 350 km north of Perth.  The Waitsia gas field  occurs within  the Geraldton  Sandplains  bioregion  of Western  Australia  (WA)  in  predominantly cleared agricultural land.   

The WS1E  Project  comprises  upgrades  to  existing  equipment  and  installation  of  new  infrastructure including:  

Upgrade  and  install  new  infrastructure  within  the  XPF  to  increase  production  capacity  to30 TJ/day,

Connecting  a  previously  drilled  well  (the Waitsia‐02  appraisal  well)  to  the  XPF  to  commenceextended production testing,

Evaporation pond construction, and

Construction of the Waitsia Gas Export Pipeline which connects the XPF to the Dampier BunburyNatural Gas Pipeline (DBNGP).

These activities are located entirely within Petroleum Title – Production Licence L1. 

2.2 Scope 

The scope of this OSCP is limited to activities associated with the WS1E Project which are managed under the WS1E Project Construction EP’s that include: 

Waitsia Stage 1 Expansion Project: Facilities Construction Environment Plan (P‐WGP1‐017)

Waitsia Stage 1 Expansion Project: Waitsia Gas Export Pipeline Construction ‐ Environment Plan(P‐WGP1‐018)

Several spill events are outside the scope of this OSCP. These are: 

A loss of well control event which is managed under the WIA OSCP (HSE‐OP‐030),

A loss of containment from the DBGNP is outside the scope of this OSCP as this is managed by theAustralian Gas Infrastructure Group.

2.3 Geographical Area  

Activities  covered  by  this  OSCP  are  located  entirely within  Petroleum  Title  –  Production  Licence  L1 (Figure 2‐1). The L1 Production Licence is situated in the onshore North Perth Basin, and approx. 350 km from Perth and 20 km southeast of Dongara (Figure 2‐1).  

2.4 Description of the Environment 

The description of the environment within the Operational Area  is contained within Section 3 of the WS1E Project Environment Plans (P‐WGP1‐017 and P‐WGP1‐018).  

It  is  expected  that  most  spill  sources  would  be  contained  within  the  Operational  Area,  however dependent  on  the  spill  location  and  volume,  vegetation  immediately  adjacent  to  the  site  has  the potential to be exposed. The Operational Area is predominantly surrounded by agricultural land, with an area of  intact vegetation present to the southeast of the Operational Area associated with Ejarno Spring. Ejarno Spring is a groundwater dependent ecosystem (GDE) and comprises vegetation in good condition. Ejarno Springs is expected to support local fauna and wildlife communities.  

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As identified in the Waitsia Stage 1 Expansion Construction EP’s, there are no known Environmentally Sensitive Areas  (ESA’s)  that occur within close proximity of the Operational Area. The nearest ESA  is approximately  3  km  to  the  south  of  the  Operational  Area whilst  the  nearest  conservation  (nature) reserve is located approximately 3.6 km south of the Operational Area (Figure 2‐2).  

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Figure 2‐1: Waitsia Gas Project (Production Licence L1) and Operational Area for this EP 

Waitsia Stage 1 Expansion Project: Construction Oil Spill Contingency Plan 

 

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Figure 2‐2: Conservation Significant Areas 

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2.5 Description of Activities 

This OSCP applies to Waitsia Stage 1 Expansion Construction EP’s. Activities that are covered by these Plans are described in Section 2 of the Waitsia Stage 1 Expansion Construction EP’s and haven’t been described again. 

2.6 Associated Documents  

MEPAU  documents  relevant  to  this  OSCP  are  listed  in  Table  2‐1.  The  overall  hierarchy  of  the  key documents associated with this OSCP are displayed in Figure 2‐3. 

Table 2‐1: OSCP Associated Documents 

Document Title  Number 

Waitsia Stage 1 Expansion Project: Facilities Construction Environment Plan   P‐WGP1‐017 

Waitsia Stage 1 Expansion Project: Waitsia Gas Export Pipeline Construction ‐ Environment Plan  P‐WGP1‐018 

Perth Basin Operations Emergency Response Plan  PB‐HSE‐PLN‐007 

Perth Basin Oil Spill Contingency Plan  PB‐HSE‐PLN‐009 

Perth Basin Emergency Management Plan   HSE‐ER‐031 

Crisis Management Plan  MEP‐HSE‐MAN‐003 

Waitsia Stage 1 Expansion Project: Construction Emergency Response Plan (bridging document)  XYR‐EXP‐TH‐021 

Figure 2‐3: Hierarchy of Systems, Practices and Procedures 

2.7 OSCP Review 

Given the nature of the WS1E Project Construction EP’s, MEPAU are unlikely to require the OSCP to be in place for a period exceeding 2.5 years. However, in accordance with the PGER(E)R, this OSCP will be reviewed when: 

The OSCP has been approved for a period of 2.5 years

There is a significant change to the operations to which this OSCP relates

There is a change to the operator of the activity (from MEPAU)

Crisis Management Plan

[MEP‐HSE‐MAN‐003]

Perth Basin Emergency Management Plan

[HSE‐ER‐031]

Perth Basin Emergency Response Plan

[PB‐HSE‐PLN‐007]

Perth Basin Emergency Response Plan 

[PB‐HSE‐PLN‐007]

Waitsia Stage 1E Construction Emergency Response Plan*

[XYR‐EXP‐TH‐021]

Waitsia Stage 1E Construction Oil Spill Contingency Plan

[P‐WGP1‐020]

Perth Basin Oil Spill Contingency Plan 

[PB‐HSE‐PLN‐009]

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3.0 CREDIBLE SPILL SCENARIO’S 

The Waitsia Stage 1 Project Expansion Construction EP’s evaluated the proposed activities and identified several credible spill scenarios that are associated with construction activities. These scenarios were: 

Release of minor volumes of hydrocarbons / chemicals during handling, transfer and storage  

Release of hydrocarbons during tie‐in of piping to the Waitsia‐02 flowline  

Loss of Well Control event during tie‐in to the Waitsia‐02 well1.  

Scenarios associated with this OSCP are detailed in Table 3‐1 which includes the following information: 

Scenario name,  

Potential sources,  

Credible volumes,  

Oil type,  

Zone of potential impact (ZPI) description.  

Table 3‐1: Spill Scenario Information  

Scenario Name Potential Source  Credible 

Volume  Hydrocarbon 

Type  Worst‐case ZPI 

Release of minor volumes of hydrocarbons / chemicals during handling, transfer and storage  

Refuelling, storage, handling etc. 

<2 m3  Diesel   Soils within the Operational Area are 

comprised almost entirely of quartz sand 

(Blacktop 20172). Diesel and condensate 

have a high viscosity and based Grimaz et. 

al. (no date)3 the pool area (or Zone of 

potential impact) is expected to be in the 

order of 104 m2 with a penetration depth 

of 1.8 m; where intervention is not 

conducted. 

The Operational Area is comprised of an 

area in the order of 242,000 m2. In 

comparison the magnitude of the area 

potentially affected by a spill is 104 m2 

indicating that the Zone of Potential 

Impact would be to within the Operational 

Area or calculated to cover an area of 

approximately 0.04 % within the 

Operational Area. 

Release of hydrocarbons during tie‐in to the Waitsia‐02 flowline  

Tie‐in to the Waitisa‐02 flowline 

<2 m3  Condensate 

 

1 A LOWC event is outside the scope of this OSCP. In the event of a LOWC event, the WIA OSCOP [HSE‐OP‐030] is to be 

activated.  2 Blacktop. 2017. Geotechnical and soils assessment of the site. (Unpublished report to MEPAU). 3 Grimaz, S, Allen, S, Stewart, JR, and Dolcetti, G. No date. Fast prediction of the evolution of oil penetration into the soil 

immediately  after  an  accidental  spillage  for  rapid‐response  purpose.  Available  online  from: 

http://www.aidic.it/CISAP3/webpapers/21Grimaz.pdf 

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4.0 OIL SPILL RESPONSE PREPAREDNESS 

4.1 Tiered Response to Credible Oil Spill Scenarios 

The OSC  is  responsible  for determining  the Emergency Level  for each spill event  in accordance with MEPAU’s Perth Basin Operations ERP [PB‐HSE‐PLN‐007] which  is summarised  in Table 4‐1.  If the spill severity  is  unknown,  the  worst  case  is  assumed  to  determine  the  Emergency  Level,  as  it  is  always possible to scale down. 

Table 4‐1: Spill Scenario Information  

Emergency Level 

Indicative Potential Spill Volume (litres)  

Description 

Level 1 (Incident) 

<500L  An incident that can be controlled by the use of resources normally available at the facility or Site concerned, without the need to mobilise the MEPAU EMT or other external assistance 

Level 2 (Emergency) 

>500L An incident that cannot be controlled by the use of normally available facility or Site resources alone and requires external support and resources to manage the situation. 

Level 3 

(Crisis) 

An incident that has a wide‐ranging impact on MEPAU and may require mobilisation of external state or national resources to bring the situation under control 

4.2 Termination of Response  

Continual  monitoring  and  assessment  of  the  incident  are  used  to  determine  when  response  and recovery measures may be terminated, based on the criteria described in Table 4‐2. Given the nature of the spill scenarios associated with this plan, termination criteria for Tier Level 1 spill events are to be made alone by MEPAU. For larger spill events (Tier Level 2 and 3 events) it is expected that this decision would be made by MEPAU but accepted via written correspondence with the Department of Mines, Industry Regulation and Safety.  

Table 4‐2: Response Termination Criteria 

Emergency Level 

Description 

Level 1 (Incident) 

Area is visually free of hydrocarbon contamination

Level 2 (Emergency) 

Soil sampling indicates the area is free of hydrocarbon contamination; and

Groundwater sampling indicates the area is free of hydrocarbon contamination

Level 3 

(Crisis) 

4.3 Response Equipment / Resources 

The following resources are available within the Operational Area (as defined by the Environment Plans) for immediate response including: 

Mobile Wheelie bin spill kits: including absorbent pads, shovels and bags;

Light vehicles;

Hydrocarbon disposal containers (Empty 200L drums, 1000L bulki tanks);

Plastic sheeting;

PPE – rubber gloves, goggles, respirator masks;

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Portable air driven diaphragm pumps.

Additional specific external resources that may be used in spill response / remediation activities include: 

Bobcats,

Cranes,

Vacuum truck,

Bulk solid waste receptacles / disposal,

Labour, and

Laboratory services for environmental sampling.

These resources are available to MEPAU and can be activated as identified in Section 5.4. 

4.4 Personnel 

Personnel will be available for the duration of construction activities covered under the WS1E Project EP’s. Key positions include: 

Project Manager,

PIC,

MEPAU Site‐representative, and

Contractor’s Construction Manager.

In addition to staff associated with the WS1E Project EP’s, MEPAU have access to local staff that operate MEPAU’s existing facilities based out of the Dongara Production Facility. Personnel from MEPAU’s head office in Perth can also be mobilised to the Operational Area with mobilisation times in the order of 6 hours.  In addition to this, MEPAU has access to labour hire companies to enable additional personnel to be contracted to support a spill event if required. 

4.5 Testing  

The PGER(E)R and PP(E)R require the OSCP to be tested at specified intervals noting that the specified intervals may include:  

When introduced,

When significantly amended,

Not later than 12 months after the most recent test,

When a new location for the activity is added, or

When a new facility or structure under the scope of the OSCP becomes operational.

MEPAU plan to test this OSCP via a desktop communications exercise prior to activities commencing. 

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5.0 STRUCTURE, ROLES AND RESPONSIBILITIES  

MEPAU’s  Perth  Basin  Operations  ERP  [PB‐HSE‐PLN‐007]  describes  the  Emergency  Response Organisation.  In  summary,  MEPAU’s  emergency  response  organisation  consists  of  a  multi‐tiered structure and includes the following: 

Site Emergency Response Team (ERT)

Perth Emergency Management Team (EMT)

Perth Crisis Management Team (CMT)

The Perth EMT and CMT is staffed by all head office staff. Depending on the type and severity of the situation, an  individual may have more than one role. The general structure of the ERT/EMT/CMT  is provided in Figure 5‐1. 

Figure 5‐1: EMT / ERT Organisation 

5.1 EMT Activation  

The EMT activation process is described in Figure 1‐1 with triggers for activation included in the initial Response Actions lists in Table 1‐1 of this Plan. Further information to inform activation of the EMT are included in the emergency definitions in Section 4.1. 

5.2 Roles and Responsibilities 

Specific responsibilities detailed for the initial response actions (Table 1‐1) are summarised in Table 5‐1. 

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Table 5‐1: Summary of OSCP Roles and Responsibilities 

Role  Responsibility 

All  Notify on‐site management of all spill events

OSC  Assess situation and call out required services to respond to the event,

Determine the Emergency Level,

Notify the EMT and call out the ERT, 

Mobilise spill equipment to contain spillage where possible /safe to do so,

Classify the spill event (as reportable or recordable) and notify HES advisor.

PIC / Construction Manager 

Recover hydrocarbons and contaminated soil from spill site,

Conduct soil / groundwater monitoring / sampling,

Backfill excavated areas with clean fill,

Complete spill site re‐instatement,

Response termination, and

Complete incident investigation

MEPAU Senior Environmental 

Advisor 

Regulatory reporting in accordance with the relevant EP,

Management of Soil / groundwater monitoring / sampling.

5.3 Training 

All MEPAU site personnel are trained in emergency response as per the requirements of the anticipated emergencies as detailed in MEPAU’s Emergency Response Competency Assessment [PB‐OPS‐TRN‐005] process and MEPAU’s Perth Basin Operations ERP [PB‐HSE‐PLN‐007].  

Internal training for operational personnel includes the following: 

WS1E Project EP HSE inductions and orientation;

Participation  in  annual  exercise  /  training  schedules.  These  include  at  least  one  emergencyresponse exercise;

Use of site specific equipment including emergency / spill response items.

Records  of  internal  and  external  training,  exercises  and  drills  conducted  are maintained  by MEPAU within the HSE database.   

Specialist  equipment,  such  as  bobcats,  cranes  and  vacuum  trucks  that  require  specific  training  and competence requirements is to be operated by external contractors that hold the required training and competence certifications. 

5.4 Contact Directory 

MEPAU maintain  an  external  Emergency Response Contact Directory  [HSE‐ER‐035].  This Directory  is maintained and kept up‐to date by MEPAU, thus is kept as a stand‐alone document. The most recent version of this document (current at the time of writing this OSCP) is attached as Appendix A. 

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6.0 SPILL RECOVERY, WASTE MANAGEMENT AND COST RECOVERY 

6.1 Spill Recovery Method 

Based  upon  the  credible  spill  events within  this  OSCP,  the  recovery methods  for  hydrocarbons  and contaminated soils is summarised in Table 6‐1. 

Table 6‐1: List of Recovery Methods 

Type of contamination  Methods of recovery  

Free Product (liquid or 

solid)  

1. Vacuum up liquid.

2. Transfer it into 200L drums, bags, 1000L bulki tanks or specialist 3rd party Vacuum

truck with storage tank (Toxfree / Solo Resource Recovery)

3. Store in bunded area.

4. Transport to disposal facility.

Surface hydrocarbon on 

ground  

1. Spread absorbent material or lime on affected ground surface. Remove (excavate)

and replace absorbent product regularly until evidence of hydrocarbon draw

ceases.

2. Lay plastic sheet/tarpaulin in a disposal holding area (to be designated in the event

of a spill).

3. Install bunding in disposal holding area.

4. Remove contaminated product to the disposal holding area.

Contaminated Soils   1. Hydrocarbon contaminated soils are to be removed entirely by either manual or

mechanical methods.

2. Remove contaminated soils to a designated disposal holding area.

3. Sample contaminated soils against solid waste to landfill guidelines to determine

method of disposal.

4. Contaminated soil is to be removed by a licensed carrier to an approved facility.

5. Sample soil underneath and around contaminated site to determine if all

contamination has been removed.

6.2 Monitoring 

In the event of an oil spill, appropriate and adequate testing and monitoring would be conducted to ensure  that  the  immediate  and  adjacent  area  is  not  impacted  in  the  long  term.    These  testing  and monitoring activities would be reported to DMIRS as required, but not limited to the annual report. 

MEPAU would utilise contractors that are currently engaged to conduct environmental sampling at it’s other Perth Basin Facilities, who currently sample and analyse groundwater quality on a quarterly basis. 

6.3 Waste Management 

Contaminated material  resulting  from  an  oil  spill  requires  removal  by  an  accredited  contractor  and disposed of in an appropriate class landfill facility. 

Where  a  small  spill  has  occurred,  local  landfill  facilities  are  to  be  consulted  for  advice  on  dilution requirements (i.e. adding of clean soils to dilute contaminant concentration).  

For  larger  spills,  where  the  total  quantity  of  contaminated  soil  is  uncertain,  the  management  of contaminated waste includes:  

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1. Samples to be taken and waste material tested by NATA accredited laboratory to identify

contaminant concentrations present.

2. Number of samples taken and general methodology to be commensurate with DEC Guidelines for

the Development of Sampling and Analysis Programs (2001).

3. Results from laboratory analysis to be compared with the criteria defined in the DEC Landfill Waste

Classification and Waste Definitions Guideline 1996 (as amended in 2009).

4. Waste material to be removed from site and disposed of at the appropriate class landfill facility (as

directed in the abovementioned DEC Landfill Guidelines) – prior to the completion of site clean‐up.

Note: appropriately qualified consultants or contractors will be engaged for soil  testing, analysis and removal and disposal.  

6.4 Oiled Wildlife Response  

The Department of Biodiversity, Conservation and Attractions (DBCA) is the lead agency in WA for an oiled wildlife response technique. DBCA has the responsibility and statutory authority to treat, protect and  destroy  wildlife  as  outlined  in  the Wildlife  Conservation  Act  1950.  DBCA  also  has  a  legislative requirement to ensure the humane treatment, housing and release or euthanising of fauna under the Animal Welfare Act 2002.  

In the event of an emergency event where oiled wildlife were encountered the DBCA Wildcare Helpline shall be immediately consulted for advice on the management of affected fauna. This is reflected in the incident reporting table of the EP (Tale 6‐4).  

Given the nature of the spill events, and in accordance with the WA Oiled Wildlife response plan, as only single oiled animals are expected to be encountered, they would be treated on direction of DBCA using local  resources  (veterinaries, wildlife  carers or Parks and Wildlife  staff).  If  additional  resources were required, MEPAU has access to labour hire companies and external environmental consultants that can help during an escalation of Oiled wildlife response as directed by the EMT. 

6.5 Cost Recovery 

All expenses associated with response, recovery and remediation and monitoring resulting from an oil spill is to be covered by MEPAU, as operator on behalf of L1 joint venture.  MEPAU Insurance certificates include: Property Damage and Public Liability. 

6.6 Reporting Requirements 

Spill response reporting requirements are detailed in Section 6.2.8 of the WS1E Project EP’s and thus have not been duplicated here.  

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11.0 REFERENCES 

Department of Water (DoW) (2013). Water Quality Protection Note 26 ‐ Liners for containing pollutants.  Department  of  Water,  Western  Australia.  Available  online  from: https://www.water.wa.gov.au/__data/assets/pdf_file/0012/4062/84590.pdf 

Blacktop  (2017).  Geotechnical  and  soils  assessment  of  the  site  (Unpublished  report  to MEPAU). 

Enscope  (2019).  Environmental  Commissioning  Management  Plan,  September  2019. Unpublished report prepared for MEPAU. 

Herring  Storer  Acoustics  (2019).  Xyris  Processing  Facility:  Acoustic  Assessment,  July  2019. Unpublished report prepared for MEPAU.  

John  Cecchi  Heritage  Management  Consultancy  (JCHMC)  (2015).  Report  on  an Archaeological Survey of AWE Waitsia Project, March 2015 (Unpublished report to AWE). 

Kern  A.  (1997).  Hydrogeology  of  the  Coastal  Plain  between  Cervantes  and  Leeman,  Perth Basin. Report HG 3, Water and Rivers Commission Perth, Western Australia. 

MEPAU  (2018).  Annual  Groundwater  Report  July  2017  to  June  2018.  Internal  MEPAU unpublished report. 

MEPAU  (2019).  Perth  Basin  Facilities  Environment  Plan  (P‐WGP1‐023).  Draft  Report  under assessment by DMIRS (update of existing EP).  

Ramboll  Australia  Pty  Ltd  (Ramboll)  (2019).  Xyris  Production  Facility:  Air  Dispersion Modelling Report, July 2019 Unpublished report prepared for MEPAU. 

R  and  E O’Connor  Pty  Ltd  (REO)  (2015).  Aboriginal  Heritage  Survey  of  the Waitsia  Project Area, March 2015 Unpublished report to AWE). 

Terra Rosa Consulting (TRC) (2017). Report on an archaeological assessment at the Waitsia‐03 project area for AWE Limited, December 2017 (Unpublished report to AWE).