Environmental Commissioning Plan

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Mid-West LNG Project

Works Approval Application (Attachment 3A)

Environmental Commissioning Plan

Revision Date Description Originator Checked Approved

A 15 July 2020 Issued for Internal Review BL DBT BL

1 30 July 2020 Initial Issue BL DBT BL

2 12 Jan 2021 Phase 1 and Phase 2 BL DBT BL

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1 Introduction

This document provides a general overview of environmental commissioning of Phase 1 and Phase 2 of the Mid-West LNG Plant, that is the testing undertaken to validate actual environmental performance of the facility relative to predicted performance.

The environmental commissioning process will effectively be identical for both phases, with the activities undertaken for Phase 1 to be repeated at a later date for environmental commissioning of Phase 2. At this stage the timing for Phase 2 is yet to be finalised and the estimates provided below are subject to change.

2 Overall Schedule

Subject to the receipt of appropriate approvals the following schedule has been developed for the Mid-West LNG Project:

• LNG Plant Phase 1:

o Construction: June 2021 – July 2021 o Commissioning: August 2021

o Operation: September 2021

• LNG Plant Phase 2:

o Construction: June 2022 – July 2022 o Commissioning: August 2022

o Operation: September 2022

3 Commissioning Schedule

The environmental commissioning process and schedule is summarised below

3.1 Stage 1 – Construction Verification & Hydrostatic Leak Testing

Construction verification of the Mid-West LNG Plant and associated Power Station and testing of on-site fabrication and installation works to confirm that the applicable rules, standards and specifications have been met, including any conditions of the Works Approval. This includes documented hydrostatic leak testing of site welded pipework prior to introduction of hydrocarbons (module pipework having already been hydrostatically leak tested during factory acceptance testing at the suppliers premises, prior to shipping to site).

Construction verification under Stage 1 is estimated to take approximately 2 weeks to complete and hydrostatic leak testing is expected take approximately 1 week to complete;

construction verification and hydrostatic leak testing will be completed concurrently.

3.2 Stage 2 – Function Testing (Pre-Commissioning)

During this stage, specific items of equipment will undergo energisation, direction and uncoupled testing to ensure tolerances and testing procedures comply with vendor manuals and recommendations. In addition, safety devices and instrumentations will be fully tested

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and operational in remote and local operation modes. Stage 2 is estimated to take approximately 1 week to complete, and is expected to occur post Stage 1.

3.3 Stage 3 – Commissioning

3.3.1 Stage 3A – No Load Commissioning

During this stage the process control system is tested as far is practical, to ensure correct operation and interaction between plant (liquefaction plant, power station, LNG storage and road tanker filling). Stage 3A is estimated to take approximately 1 week to complete, and will occur post Stage 2.

3.3.2 Stage 3B – Dry Commissioning

During this stage all moisture within the LNG process plant must be removed before wet commissioning can take place. This is achieved by flowing dry gas, being pre-treated natural gas, through the cold box system to pick up any moisture left over from the installation and testing processes. The gas will be directed to the Cold Flare for combustion. Stage 3B is estimated to take 1 week to complete, and will occur post Stage 3A.

3.3.3 Stage 3C – Wet Commissioning

During this stage mixed refrigerant is introduced to the LNG Plant and gas to the Power Station and the build up to steady state operation commences. Stage 3C is estimated to take approximately 0.5 weeks to complete, and will occur post Stage 3B.

3.4 Stage 4 - Performance Testing

During this stage gas supply is gradually increased into the facility and the performance of the LNG Plant and Power Station is optimised and assessed building to full operational throughput. This is estimated to take approximately 1 week to complete, and will occur post Stage 3C.

Commissioning emissions testing will take place during this stage. An Environmental Commissioning Report will be submitted to DWER within 60 days of completion of Stage 4, confirming that the key infrastructure is capable of operating in accordance with the specific requirements of the Works Approval.

3.5 Stage 5 – Time-Limited Operations

Following submission of the Environmental Commissioning Report, the applicant requests a period of up to 180 days of time-limited operations, whereby the Mid-West LNG Plant and Power Station could commence operations whilst a Licence Application is in the process of assessment and approval by DWER.

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4 Key Inputs and Outputs Used in the Environmental Commissioning Process

Inputs for environmental commissioning of the Mid-West LNG Plant and Power Station include:

• Natural gas

• Mixed Refrigerants

• Engine oil

• Diesel (for black start genset)

The key output of the Power Station is electricity to supply the Mid-West LNG Plant, while the key output of the Mid-West LNG plant is liquified natural gas.

5 Expected Emissions During Environmental Commissioning Process

Key emissions during environmental commissioning are as follows:

• Air emissions from backup diesel fired generator

• Air emissions from gas fired generators

• Air emissions from Cold Flare

• Noise from operating plant and equipment Key air emissions are summarised below:

5.1 Oxides of Nitrogen (NO

x

)

Emissions of Oxides of Nitrogen result from the combustion of hydrocarbons, especially at high temperatures. Commissioning activities, including tuning of the gas power station and Cold Flare, will help to keep NOx emissions to a minimum during future normal operations.

5.2 Sulphur Dioxide (SO

2

)

SO2 emissions from power generation are largely a result of the sulphur content in the fuel consumed. Western Australian natural gas contains low levels of sulphur, thus the emission of SO2 resulting from natural gas combustion is very low. Due to the high efficiency of the gas generator units, the fuel consumed per unit of energy produced is also lower, meaning lower SO2 emission intensity than less efficient gas fired generators.

5.3 Particulate Matter (PM)

Particulate emissions result from the carryover of non-combustible trace compounds in the fuel and lubricating oil as well as from incomplete combustion. Generally, gas fired reciprocating engines emit very low quantities of particulates.

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5.4 Carbon Monoxide (CO)

Carbon monoxide emissions generally result from incomplete combustion, the expected emissions of CO during commissioning are extremely low.

6 Commissioning Emissions Testing

During Stage 4 of Commissioning (Performance Testing), qualified and NATA accredited air monitoring technicians will be on site to monitor point source emissions to air from each of the exhaust stacks and the Cold Flare. The objective being to establish emissions at steady state, confirm that the steady state emissions do not exceed those indicated in the Works Approval and further provide feedback and live data to enable the fine tuning of the facility to minimise emissions and optimise process efficiency.

Emission testing will be carried out against manufacturer specifications and in compliance with WA Continuous Emission Monitoring System (CEMS) Code for Stationary Source Air Emissions (Department of Environment Regulation, 2016).

7 Risk Management

7.1 Reporting

Any discharges of waste likely to cause pollution or environmental harm (other than those within any limits authorised under the Works Approval) will be reported as soon as practicable to the Department of Water and Environmental Regulation.

Details of any environmental incident that takes place during environmental commissioning will be reported in the Environmental Commissioning Report that will be submitted to DWER within 60 days of completion of Stage 4.

7.2 Unplanned or Excessive Emissions

Unplanned emissions or emission exceedances (if applicable) will be managed by adjusting the load of the engine/LNG Plant where necessary. If higher than expected emissions are discovered during testing, engines/LNG Plant processes will be retuned until satisfactory readings are reached.

7.3 Oil and Chemicals Management

All liquid hydrocarbons (and other harmful chemicals) utilised will be managed in accordance with a Liquid Hydrocarbon Management Plan (LHMP) to be developed during construction of the process plant. The LHMP will include the use of liquid hydrocarbon storage containers compliant to AS 1940 or, for other chemicals, other appropriate Australian or international standards. Spills will be managed under an Oil Spill Contingency Plan to be developed prior to the start of construction. Ongoing storage of chemicals and liquid hydrocarbons will be

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managed by conducting periodic inspections of chemical and hydrocarbon storage areas to confirm compliance with any Licence conditions and applicable Australian Standards.

7.4 Surface Water Contamination

A storm water assessment is underway for the facility and will provide the basis for the development of a Storm Water Management Plan (SWMP) to be finalised prior to the start of construction. The SWMP will include management of any water potentially contaminated or contaminated with liquid hydrocarbons, it is anticipated that this will be managed with oily water separation systems (if required) and/or removal and disposal of the contaminated water off-site by licenced contractors.

8 Variance of Environmental Commissioning to Standard Operations

8.1 Inputs

Input Variance to Standard Operations

Natural Gas No change

Mixed Refrigerant First fill volume during commissioning will be greater than the minor quantities required for standard operations

Engine Oil First fill volume during commissioning will be greater than the minor quantities required for standard operations

Diesel (for black start genset)

First fill volume during commissioning will be greater than the minor quantities required for standard operations (backup power only)

8.2 Outputs

During dry commissioning the dry natural gas used to remove moisture from the system will be diverted to the Cold Flare for combustion, under normal operations the natural gas would be liquefied and transferred to the LNG storage tanks and the Cold Flare will only operate to combust any hydrocarbons released in the event of an emergency overpressure event or during depressurisation of equipment for maintenance. Therefore the ongoing emissions from the Cold Flare are expected to be minimal.

The LNG Plant and associated Power Station operate most efficiently and with the lowest emissions intensity per unit of LNG produced when performing at a steady state close to nameplate capacity.

This will not always be the case such as during commissioning where emissions are likely to fluctuate. As a result of this, emissions are likely to be less predictable during commissioning in comparison with standard operating conditions.

Environmental Commissioning Plan

Mid-West LNG Project

Works Approval Application (Attachment 3A)