Reports and Data in Relation to the Works

Works Approval

Works Approval Number W6026/2017/1

Works Approval Holder Australian Potash Limited

Registered business address 31 Ord St WEST PERTH WA 6005

Address for notifications 31 Ord St WEST PERTH WA 6005

Duration 10 April 2017 to 9 April 2018

Prescribed Premises Category 14 – Solar salt manufacturing

Premises Lake Wells Potash Trial Exploration tenement E38/2742

This Works Approval is granted to the Works Approval Holder, subject to the following conditions, on 10 April 2017, by:

Date signed: 10 April 2017 Tim Gentle Manager Licensing – Resource Industries an officer delegated under section 20 of the Environmental Protection Act 1986 (WA)

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Premises Description The Works Approval Holder is proposing to develop a trial evaporation pond to extract a bulk sample of potassium salt under field conditions. It is proposed the outcome of the trial will contribute to the understanding of factors influencing operational efficiency and product quality. The Works Approval Holder will be carrying out activities at the Premises which fall within Category 14 – Solar salt manufacturing, and are Prescribed Premises under the EP Act. Conditions

Environmental compliance 1. The Works Approval Holder must comply with the EP Act and all regulations prescribed under the EP Act applicable to the Premises including: (a) The duties of an occupier under s 61; (b) The duty to notify the CEO of discharges of waste under s 72; and (c) Not causing, or doing anything that is likely to cause, an offence under the EP Act, except where the Works Approval Holder does something in accordance with a Condition which expressly states that a defence under s 74A of the EP Act may be available. Premises 2. The Works Approval Holder must carry out the Works within the Premises in accordance with the requirements set out in Schedule 2. 3. This Works Approval applies to the Premises defined in the Premises Description Table, and as depicted in the Premises Map in Schedule 1.

Premises Description

Legal land description, reserve or tenement (all or part)

Exploration tenement E38/2742 (part)

Location of Works 4. The Works Approval Holder must locate the Works generally in accordance with the Site Plans in Schedule 3.

Infrastructure and Equipment 5. Key items of infrastructure which are required to be built are listed in the Infrastructure Requirements Table. The Works Approval Holder must not depart from the requirements specified in column 2 of the Infrastructure Requirements Table except: (a) where such departure is minor in nature and does not materially change or affect the infrastructure; or

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(b) where such departure improves the functionality of the infrastructure and does not increase risks to public health, public amenity or the environment; and all other Conditions in this Works Approval are still satisfied.

Infrastructure Requirements

Infrastructure Requirements (Design and Construction)

Pilot pond complex As per general layout plan. consisting of 4 ponds Total extent of disturbance not exceed 0.8 ha

Internal area of ponds to be fully lined with 1.5mm HDPE liner or equivalent to Pond liner -9 achieve a permeability of 1 x 10 m/s

Access platform Fabricated off-site and delivered to site and installed

6. Subject to Condition 7, on completion of the Works, the Works Approval Holder must provide to the CEO certification from a suitably qualified engineer confirming each item of infrastructure or component of infrastructure specified in column 1 with the requirements specified in column 2, as set out in the Infrastructure Requirements Table, have been constructed with no material defects. 7. If any departures to the specified Works have occurred, the Works Approval Holder must provide the CEO with a list of departures which are certified as complying with Condition 5 at the same time, and from the same engineer, as the certification under Condition 6. Records and Information 8. The Works Approval Holder must maintain accurate records including information, reports and data in relation to the Works. 9. All information and records required under this Works Approval must: (a) be legible; (b) if amended, be amended in such a way that the original and subsequent amendments remain legible or are capable of retrieval; and (c) be retained for 6 years after the expiry of this Works Approval.

Reports 10. If requested by the CEO from time to time, the Works Approval Holder must provide the CEO with reports or information relating to the Works, the Premises or any condition in this Works Approval (including data from any monitoring conditions or environmental risk assessment studies). 11. Reports or information must be in such form as the CEO may require in a CEO Request.

Requests for Information 12. The Works Approval Holder must comply with a CEO Request, within 7 days from the date of the CEO Request or such other period specified in the CEO Request.

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Definitions and Interpretation

Definitions In this Works Approval, the following terms have the following meanings: Books has the same meaning given to that term under the EP Act. CEO for the purposes of notification means: Director General Department Administering the Environmental Protection Act 1986 Locked Bag 33 Cloisters Square PERTH WA 6850 [email protected] CEO Request means a request for Books or other sources of information to be produced, made by an Inspector or CEO to the Works Approval Holder in writing and sent to the Works Approval Holder’s address for notifications, as described at the front of this Works Approval, in relation to: (a) compliance with the EP Act or this Works Approval; (b) the Books or other sources of information maintained in accordance with this Works Approval; or (c) the Books or other sources of information relating to Emissions from the Premises. Condition means a condition to which this Works Approval is subject under s 62 of the EP Act. Department means the department established under section 35 of the Public Sector Management Act 1994 and designated as responsible for the administration of Part V, Division 3 of the EP Act. Request means a request for Books or other sources of information to be produced, made by an Inspector or the CEO to the Works Approval Holder in writing and sent to the Works Approval Holder’s address for notifications, as described at the front of this Works Approval, in relation to: (d) compliance with the EP Act or this Works Approval; (e) the Books or other sources of information maintained in accordance with this Works Approval; or (f) the Books or other sources of information relating to Emissions from the Premises. Discharge has the same meaning given to that term under the EP Act. Emission has the same meaning given to that term under the EP Act. Environmental Harm has the same meaning given to that term under the EP Act. EP Act means the Environmental Protection Act 1986 (WA). EP Regulations means the Environmental Protection Regulations 1987 (WA).Premises refers to the premises to which this Works Approval applies, as specified at the front of this Works Approval and as shown on the map in Schedule 1 to this Works Approval.Works Approval refers to this document, which evidences the grant of the works approval by the CEO under s 54 of the EP Act, subject to the Conditions. Works Approval Holder refers to the occupier of the Premises being the person to whom

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this Works Approval has been granted, as specified at the front of this Works Approval. Works means the Works listed in Schedule 2 of this Works Approval to be carried out at the Premises, subject to the Conditions. Interpretation In this Works Approval: (a) the words ‘including’, ‘includes’ and ‘include’ will be read as if followed by the words ‘without limitation’; (b) where any word or phrase is given a defined meaning, any other part of speech or other grammatical form of that word or phrase has a corresponding meaning; (c) where tables are used in a Condition, each row in a table constitutes a separate Condition; and (d) any reference to an Australian or other standard, guideline or code of practice in this Works Approval means the version of the standard, guideline or code of practice in force at the time of granting of this Works Approval and includes any amendments to the standard, guideline or code of practice which may occur from time to time during the course of the Works Approval.

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Schedule 1: Maps

Premises Map The Premises are shown in the maps below. The red line depicts the boundary to the Premises.

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Schedule 2: Works

The Works to be carried out on the Premises are specified in the table below:

Table 3: Authorised Works

Item Works Specifications/Drawings

1 Pilot complex (comprising 4 ponds), access General layout of ponds plan shown in Schedule road and platforms, laydown and topsoil storage 4. areas.

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Schedule 3: Site Plan

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Schedule 4: General Layout of Ponds

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Decision Report

Concurrent application for Works Approval and Licence

Division 3, Part V Environmental Protection Act 1986

Applicant: Australian Potash Limited

ACN: 149 390 394

Works Approval Number: W6026/2017/1

Licence Number: L9027/2017/1

File Number: DER2016/002540 and DER2016/002541

Premises: Lake Wells Potash Project Exploration tenement E38/2742 LAVERTON WA 6440

Date of report: Monday, 10 April 2017

Status of Report Final

Table of Contents

Definitions of terms and acronyms ...... 4 1. Purpose and scope of assessment ...... 5 2. Background ...... 5 3. Overview of Premises...... 5 3.1 Infrastructure ...... 5 3.2 Operational aspects ...... 6 3.2.1 Construction ...... 6 3.2.2 Operation ...... 6 4. Legislative context...... 8 4.1 Part IV of the EP Act ...... 8 4.2 Other relevant approvals ...... 8 4.2.1 Department of Mines and Petroleum ...... 8 4.2.2 Department of Water ...... 8 4.3 Part V of the EP Act ...... 8 4.3.1 Guidance Statements ...... 8 5. Clearing ...... 8 6. Consultation ...... 8 7. Location and siting ...... 8 7.1 Siting context ...... 8 7.2 Residential and sensitive premises ...... 9 7.3 Specified ecosystems ...... 9 7.4 Groundwater ...... 9 7.5 Surface Water ...... 10 7.6 Meteorology ...... 10 7.6.1 Regional climatic aspects ...... 10 7.6.2 Rainfall and temperature ...... 10 8. Risk assessment ...... 11 8.1 Confirmation of potential impacts ...... 11 8.2 Risk Criteria ...... 16 8.3 Risk Treatment ...... 17 8.4 Risk Assessment – Overtopping of brine from ponds ...... 17 8.5 Risk Assessment – Leaks and spills through base of pond and/or pipeline ...... 19 8.5.1 General hazard characterisation and impact ...... 19 8.5.2 Applicant controls ...... 19

8.5.3 Key findings ...... 19 8.5.4 Consequence ...... 20 8.5.5 Likelihood of consequence ...... 20 The Delegated Officer has considered: ...... 20 8.5.6 Overall rating ...... 20 8.6 Summary of risk assessment and acceptability ...... 21 9. Determined Regulatory Controls ...... 22 9.1 Infrastructure and Equipment (works approval and licence)...... 22 9.1.1 Leaks, spills and overtopping Infrastructure and Equipment ...... 22 9.2 Specified Action (licence only) ...... 22 10. Appropriateness of Works Approval conditions ...... 22 11. Appropriateness of Licence conditions ...... 23 12. Applicant’s comments ...... 23 13. Conclusion ...... 23 Appendix 1: Key Documents Appendix 2: Summary of Applicant’s Comments on Risk Assessment and Draft Conditions Attachment 1: Issued Works Approval W6002/2016/1 Attachment 2: Issued Licence L9027/2017/1

Definitions of terms and acronyms

Term Definition

Annual Period means a 12 month period commencing from 5 April until 4 April in the following year

Applicant Australian Potash Limited

Application The application submitted to DER by Australian Potash Limited consisting of reference document Australian Potash 2016

BOM Bureau of Meteorology

Category/Categories categories of prescribed premises as set out in Schedule 1 of the EP (Cat.) Regulations

DER Department of Environment Regulation

Decision Report this document

Delegated Officer An officer under section 20 of the EP Act

DMP Department of Mines and Petroleum

DoW Department of Water

EP Act Environmental Protection Act 1986 (WA)

EP Regulations Environmental Protection Regulations 1987 (WA) ha hectare

HDPE high density polyethylene

Issued Licence The licence issued under Part V, Division 3 of the EP Act following the finalisation of this assessment

Issued Works The works approval issued under Part V, Division 3 of the EP Act Approval following the finalisation of this assessment

Minister the Minister responsible for the EP Act and associated regulations

OEPA Office of the EPA

Playa An area of flat, dried-up land, especially a desert basin from which water evaporates quickly

Premises Lake Wells Potash Trial

Primary Activities is defined in DER’s Guidance Statement: Risk Assessments to mean activities which fall within the description of the category of prescribed premises in Schedule 1 to the EP Regulations

Term Definition prescribed premises premises prescribed under Schedule 1 to the EP Regulations.

RiWI Act Rights in Water and Irrigation Act 1914

TDS total dissolved solids

1. Purpose and scope of assessment Australian Potash Limited (Applicant) has submitted an Application on 23 December 2016 for a concurrent works approval and licence under the Environmental Protection Act 1986 (EP Act) to develop a trial evaporation pond to generate a bulk sample of potassium salt under field conditions at the Lake Wells Potash Project (Premises), approximately 160 kilometres (km) north-north-east of Laverton in the Goldfields region of Western Australia. This Decision Report assesses emissions and discharges associated with the construction and operation of the following:  Trial evaporation ponds. 2. Background The Premises is located on exploration tenement E38/2742, an exploration tenement held by Lake Wells Exploration Pty Ltd. The Applicant entered into an agreement with Lake Wells Exploration Pty Ltd on 29 November 2015 to facilitate potash exploration by the Applicant on E38/2742. A copy of the agreement was provided by the Applicant to DER with the application. The tenement is located on vacant crown land and overlies the Lake Wells Pastoral Lease. The Applicant proposes to construct a small series of trial evaporation ponds within the Lake Wells salt lake for the harvesting of potassium salts. The activity of harvesting the salts will cause the premises to become prescribed under the category of solar salt manufacturing, as described in Table 1. Table 1: Prescribed Premises Categories

Classification Description Approved premises of Premises production or design capacity or throughput

Solar salt manufacturing: premises on which salt is produced by 20 tonnes of potassium Category 14 solar evaporation salt per Annual Period

3. Overview of Premises

3.1 Infrastructure The Premises infrastructure, as it relates to Category 14 activities, is detailed in Table 2 and with reference to the site layout (Figure 1). Information has been summarised from the Application. Table 2: Premises infrastructure

Infrastructure

Prescribed Activity Category 14

20 tonnes of potassium salts are expected to be harvested following an evaporation pond trial for a period of up to 12 months.

1 Pilot pond complex consisting of 4 ponds:  Pond 1 – 45m x 45m  Pond 2 – 6.7m x 7.5m  Pond 3 – 5m x 5m  Pond 4 – 5m x 5m  Pond walls to be 0.8m high with a 1m wide crest and a 1:1.5 side slopes on both inner and outer faces of the berms.

2 Internal area of the ponds will be fully lined with 1.5mm HDPE liner (or equivalent).

3 Access platform (constructed from timber). Allows access to the central area of the ponds. Fabricated off-site and delivered to site and installed.

4 Portable pump, genset and hose – used from time to time to pump the brine from one pond to another.

3.2 Operational aspects

3.2.1 Construction

The evaporation pond complex will consist of 4 individual ponds, and the entire complex will be a total of 52 m wide by 85 m long. The proposed total disturbance area will be 80 m wide by 100 m long to allow for laydown area, topsoil stockpile zones and an access track around the pilot pond facility. The ponds will be constructed using a front-end loader (Australian Potash 2016). Figure 1 shows the layout of the pond.

3.2.2 Operation Once the ponds have been constructed, the first and largest pond will be filled with brine from an existing production well located within 50 m of the pilot complex. Water from the production bore will be pumped into the first pond at a flow rate of 6 L/s. It is expected this pond will fill to a depth of 0.4 m in 2 to 3 days. Brine in this pond will then be allowed to evaporate, concentrating the amount of potassium in the brine by initially precipitating sodium and chloride out of solution. The brine will continue to evaporate until just before the point of potassium salt precipitation. Once it reaches this point, the brine will be transferred to the second largest pond for the precipitation of potassium minerals. Over a period of 12 months, the brine will be concentrated and transferred in succession to the smaller test ponds for controlled precipitation of the salts. The brine will be sampled weekly in order to evaluate the rate of evaporation and to forecast the progression of the brine through the various ponds. Mobile pumps and hoses will be used to transfer the brine between ponds. Upon completion of the trial, up to 20 tonnes of product salts will be harvested and stored in 1 tonne bulk bags to be sent to a laboratory for testing. The product salts will be harvested from the smallest pond using equipment such as a blackhoe or bobcat. There will be up to 500

tonnes of waste salt (predominantly halite salt) that will have deposited into the largest pre- concentration pond. This will also include bitterns (magnesium and calcium salts) which is expected to be less than 5%. The waste salt will be retained in the lined ponds and covered first with subsoil by pushing in the berms and then with topsoil retained from initial stripping. The Applicant will use the rehabilitated pond to test the effectiveness of revegetation procedures. Results will be used to develop a mine rehabilitation and closure plan for future large scale operations (Australian Potash 2016).

Figure 1: Pond layout

4. Legislative context

4.1 Part IV of the EP Act The proposal has not been referred to the EPA for Part IV assessment.

4.2 Other relevant approvals

4.2.1 Department of Mines and Petroleum A Programme of Works (PoW) was approved by the Department of Mines and Petroleum (DMP) for the trial pond area including 0.21ha of turkeys nest dam already cleared under PoW 60071. A second PoW was submitted to DMP in January 2017 for the remainder of the trial pond area and approved by DMP on 13 March 2017.

4.2.2 Department of Water Groundwater abstraction activities for the Premises are undertaken in accordance with the DoW groundwater licences GWL182487/1. 4.3 Part V of the EP Act

4.3.1 Guidance Statements The overarching legislative framework of this assessment is the EP Act and EP Regulations. DER Guidance Statements which inform this assessment are:  Guidance Statement: Regulatory Principles (July 2015);  Guidance Statement: Setting Conditions (October 2015);  Guidance Statement: Land Use Planning (August 2016);  Guidance Statement: Licence Duration (August 2016);  Guidance Statement: Environmental Siting (November 2016);  Guidance Statement: Decision Making (November 2016); and  Guidance Statement: Risk Assessments (November 2016). 5. Clearing

Up to 0.8 ha is required to be cleared for the trial evaporation ponds. The clearing will be assessed by DMP under the Programme of Works. 6. Consultation The Application was advertised in the West Australian on 6 March 2017 for 21 days seeking public comment. A letter inviting comment was sent to the Shire of Laverton and Department of Mines and Petroleum on 28 February 2017. DER referred the draft works approval and Decision Report on 24 March 2017 to the Applicant. 7. Location and siting

7.1 Siting context

The Premises is located approximately 160 km north-north-east of Laverton and is located on the Lake Wells Pastoral Lease, which is privately operated and is currently stocked. The workforce for the Premises will be housed at the Lake Wells station homestead, located approximately 9.2 km east-south-east of the trial ponds.

7.2 Residential and sensitive premises The distances to residential and sensitive receptors are detailed in Table 3. The closest residential area to the Premises is the Lake Wells station homestead. There are no existing facilities at the Premises. Table 3: Receptors and distance from activity boundary

Sensitive Land Uses Distance from Prescribed Activity

Residential Premises The closest residential premises from the proposed site, is the Lake Wells station homestead, 9.2km east-south-east of the trial ponds. The next closest residential area is the town of Laverton, 160km to the south-west of the proposed site.

Pastoral bore The nearest registered pastoral bore is located approximately 8 km. Groundwater used by local pastoralists is sourced from a different aquifer system.

7.3 Specified ecosystems The distances to specified ecosystems in accordance with DER’s Guidance Statement: Environmental Siting is shown in Table 4. Table 4: Specified ecosystems

Specified ecosystems Distance from the Premises*

Parks and Wildlife tenure De La Poer Range Nature Reserve, managed by DPaW is located approximately 12km to the west of the survey area.

Public Drinking Water Source Area There are no PDWSA within the Premises. (PDWSA)

Ramsar wetland There are no Ramsar wetlands near to the project area

Declared Rare Flora or priority flora There are no Declared Rare Flora or priority flora within the Premises (Botanica Consulting 2016)

Threatened Ecological Communities and There are no Threatened Ecological Communities or Priority Ecological Communities Priority Ecological Communities within the Premises (Botanica Consulting 2016)

*DER’s GIS database 7.4 Groundwater

The Application states that the major aquifers in the Laverton area of the northeastern goldfields comprise fractured rock aquifers. The regional groundwater system generally flows in a southeasterly direction along the palaeodrainage system. Australian Potash conducted some exploratory drilling which confirmed the presence of a deep tertiary valley infilled with predominantly lacustrine clays and minor sand interbeds to depths of up to 140 mgbl. The depth of groundwater at the proposed site is approximately 3 mbgl. Water quality within the project area is hypersaline, with TDS values approximately 200 000 mg/L (Australian Potash 2016). 7.5 Surface Water

The Premises is located on and adjacent to the south western part of the Lake Wells playa. The southwest arm of the playa is estimated to have a contributing catchment area of 6,600 km2 with an approximate surface area of 170 km2.

The overall palaeochannel at Lake Wells is part of a much larger internally draining system which flows towards Lake Carnegie, 100 km to the north of Lake Wells.

The Lake Wells playa surface has an extensive series of relatively large and deep depressions (up to 3-4 m), which provide significant storage during flood events. The estimated surface flow velocities along the playa are very low and typically less than 1 m/s. This reflects the very low surface gradient and also the tendency for the depressions to progressively fill as the flow progresses downstream (Australian Potash 2016). 7.6 Meteorology

7.6.1 Regional climatic aspects The Premises is located within the semi-arid zone of Western Australia which is characterised by low rainfall and a large temperate range. Heavy rainfall events can occur periodically in the summer months as a result of tropical cyclones and depressions.

7.6.2 Rainfall and temperature BOM, 2016 provides the mean rainfall and maximum temperatures for Laverton (mean maximum temperature 1991-2016 and mean rainfall 1994-2016) as shown in Figure 2. Annual rainfall in the semi-arid zone is highly variable and subject to drought periods. Pan evaporation rates for the area are estimated to be 3,600 mm/year, which exceeds the annual rainfall depth.

Figure 2: Mean temperatures and rainfall, Laverton Aero Source: Bureau of Meteorology website www.bom.gov.au 8. Risk assessment

8.1 Confirmation of potential impacts Identification of key potential emissions, pathways, receptors and confirmation of potential impacts are set out in Tables 5 and 6 below. Tables 5 and 6 also identify which potential emissions will be progressed to a full risk assessment. Some potential emissions/impacts may not receive a full risk assessment where a potential receptor or pathway cannot be identified.

Table 5: Identification of key emissions during construction

Continued to Reasoning Potential Potential Receptors Potential Pathway Potential Impacts detailed risk Emissions assessment?

No receptors present

The Delegated Officer

for for

Noise No considers that the provisions Vehicle movements No residences or of the Environmental 3.1 Construction, Protection (Noise) mobilisation on unsealed access sensitive land uses Air / wind dispersion Health and amenity Regulations 1997 and and roads within 9km section 49 of the EP Act are positioning of sufficient to regulate noise infrastructure Dust No and dust emissions during for trial construction (see Section (see evaporation ponds Noise No

infrastructurereferences) Earthworks, No residences or

Source construction of sensitive land uses Air / wind dispersion Health and amenity As above ponds within 9km Dust No

Table 6: Identification of key emissions during operation

Continued to Reasoning Potential Potential Receptors Potential Pathway Potential Impacts detailed risk Emissions assessment?

The Delegated Officer considers that due to the

surface of the lake being

highly saline, a salt crust is likely to form when not wet which will prevent dusting Health and amenity events. There are no Specified Airborne particulates No residences, sensitive Potential for salt build Ecosystems within or in a (salts) from final land uses or specified Air / wind dispersion up on vegetation No 12km radius of the Premises pond ecosystems within 9km which may prevent photosynthesis and The Delegated Officer plant respiration considers that the provisions Category 14 Operation of trial of section 49 of the EP Act are sufficient to regulate for infrastructure references) for Solar salt

evaporation ponds

manufacturing suspended particle 3.1

emissions associated with dusting from the ponds during operation.

No nearby receptors present

(see Section (see The Delegated Officer considers that the provisions Noise associated Nearest residences Air / wind dispersion Amenity No of the Environmental

with the generators greater than 9 km away Protection (Noise) Source Regulations 1997 are sufficient to regulate noise emissions during operation.

Continued to Reasoning Potential Potential Receptors Potential Pathway Potential Impacts detailed risk Emissions assessment?

Contamination of soils and potential impacts Overtopping of brine Playa vegetation Direct discharge to to fringing vegetation Yes See section 8.4 from ponds adjacent to ponds playa surface and biota on the lake surface such as algae, brine shrimp.

Potential contamination of Leaks and spills Terrestrial ecosystems Direct flow to surface surrounding soils, through base or adjacent to the spill and water body and ecosystems and Yes See section 8.5 walls of ponds and groundwater groundwater groundwater due to pipeline the high salinity content.

Continued to Reasoning Potential Potential Receptors Potential Pathway Potential Impacts detailed risk Emissions assessment?

Due to the high level of salinity it is very unlikely that fauna and birds would be attracted to the ponds. It has been determined that birds and mammals will not drink Ingestion of water hypersaline water greater would be toxic to birds than 46,000 mg/L TDS Hypersaline water Birds and other fauna Direct ingestion and other wildlife due No (Griffiths et al., 2009). The to the high level of salinity within the ponds will TDS. be greater than this (approximately 200,000 mg/L TDS). The Delegated Officer considers there is no need for further assessment.

8.2 Risk Criteria During the assessment the risk criteria in Table 7 below will be applied to determine a risk rating set out in this section 8. Table 7: Risk Criteria

Likelihood Consequence Slight Minor Moderate Major Severe Almost Certain Medium High High Extreme Extreme Likely Medium Medium High High Extreme Possible Low Medium Medium High Extreme Unlikely Low Medium Medium Medium High Rare Low Low Medium Medium High

Likelihood Consequence

The following criteria has been The following criteria has been used to determine the consequences of a risk occurring: used to determine the likelihood of the risk / opportunity occurring.

Environment Public Health* and Amenity (such as air and water quality, noise, and odour)

Almost The risk event is Severe  on-site impacts: catastrophic  Loss of life expected to occur  off-site impacts local scale: high level  Adverse health effects: high level or Certain in most or above ongoing medical treatment circumstances  off-site impacts wider scale: mid-level  Specific Consequence Criteria (for or above public health) are significantly exceeded  Mid to long term or permanent impact to an area of high conservation value or  Local scale impacts: permanent loss special significance^ of amenity  Specific Consequence Criteria (for environment) are significantly exceeded Likely The risk event will Major  on-site impacts: high level  Adverse health effects: mid-level or probably occur in  off-site impacts local scale: mid-level frequent medical treatment most circumstances  off-site impacts wider scale: low level  Specific Consequence Criteria (for public health) are exceeded  Short term impact to an area of high  Local scale impacts: high level conservation value or special significance^ impact to amenity  Specific Consequence Criteria (for environment) are exceeded Possible The risk event Moderate  on-site impacts: mid-level  Adverse health effects: low level or could occur at  off-site impacts local scale: low level occasional medical treatment some time  off-site impacts wider scale: minimal  Specific Consequence Criteria (for public health) are at risk of not being  Specific Consequence Criteria (for met environment) are at risk of not being met  Local scale impacts: mid-level impact to amenity Unlikely The risk event will Minor  on-site impacts: low level  Specific Consequence Criteria (for probably not occur public health) are likely to be met  off-site impacts local scale: minimal in most  Local scale impacts: low level impact circumstances  off-site impacts wider scale: not to amenity detectable  Specific Consequence Criteria (for environment) likely to be met Rare The risk event may Slight  on-site impact: minimal  Local scale: minimal to amenity only occur in  Specific Consequence Criteria (for  Specific Consequence Criteria (for exceptional environment) met public health) met circumstances

^ Determination of areas of high conservation value or special significance should be informed by the Guidance Statement: Environmental Siting. * In applying public health criteria, DER may have regard to the Department of Health’s, Health Risk Assessment (Scoping) Guidelines “on-site” means within the prescribed premises boundary. 8.3 Risk Treatment DER will treat risks in accordance with the Risk Treatment Matrix in Table 8 below: Table 8: Risk Treatment

Rating of Risk Acceptability Treatment Event

Extreme Unacceptable. Risk event will not be tolerated. DER may refuse application.

High Acceptable subject to multiple Risk event will be tolerated and may be subject to regulatory controls. multiple regulatory controls. This may include both outcome-based and management conditions.

Medium Acceptable, generally subject Risk event is tolerable and is likely to be subject to regulatory controls. to some regulatory controls. A preference for outcome-based conditions where practical and appropriate will be applied.

Low Acceptable, generally not Risk event is acceptable and will generally not be controlled subject to regulatory controls.

8.4 Risk Assessment – Overtopping of brine from ponds

8.4.1 General hazard characterisation and impact Normal and Abnormal Operation During normal operation of the ponds, there will be no direct emission to land, water or air. The ponds are designed to contain a 1 in 50 year storm event. The approximate ponding depth of the pre-concentration pond will be 0.3 – 0.4 m (approximately 650 cubic meters of brine). This has been calculated to allow for a 1 in 50 year, 24 hour storm event. Probability of a 1 in 50, 24 hour storm event occurring during a 6 month trial period is less than 1%. TDS within the ponds will be up to approximately 200 000 mg/L. If the brine in the ponds were to overflow to the playa surface there could be potential for death of nearby native vegetation as well as impact on any fauna which may be present. However, if they overtopped due to a storm event, the TDS would be diluted from the significant volume of rainwater. A Level 1 Fauna survey was carried out in September 2016. 124 fauna species were recorded, including 23 mammals, 61 birds, 39 reptiles and one frog. No threatened fauna as defined by the Environment Protection and Biodiversity Conservation Act 1999 were identified. Nor were any priority fauna species listed (Australian Potash 2016). The playa surface may provide habitat for ‘salt lake specialist’ invertebrate species such as salt-tolerant species of wolf spiders, tiger beetles, crickets, ants and earwigs (Australian Potash 2016). However, based on information the Applicant has collected, it appears that potential short range endemic (SRE) invertebrates (if present) are unlikely to be restricted to the proposed trial area, given the scale of playa habitat beyond the disturbance footprint. The surrounding vegetation within the playa surface is highly salt tolerant. A Level 2

vegetation survey was carried out in December 2015 and October 2016, with two vegetation communities identified; a dense, low shrub across the lake bed of Tecticornia indica and a forest of Casuarina pauper over open low scrub of Acacia burkittii within the dunes (Australian Potash 2016). Neither of the communities are considered threatened or priority species (Botanica Consulting 2016). There is potential for impacts to occur on the fringing vegetation if the ponds were to overflow, although the TDS would be diluted due to the significant amount of rainwater.

8.4.2 Proponent controls Table 9 contains a summary of controls proposed by the Applicant in regards to pond overtopping.

Table 9: Proponent controls for prevention of pond overtopping

Controls for pond overtopping

Freeboard - A 500 mm freeboard will provide storage for up to a 1 in 50 year, 24 hour storm event. Inspections - Daily inspections of the ponds to ensure freeboard is maintained

8.4.3 Key findings

The Delegated Officer has reviewed the information regarding brine overtopping impacts from the premises and has found: 1. Spillage of brine from overtopping may cause local impacts to the playa, particularly surrounding vegetation and invertebrates. 2. Proponent controls regarding freeboard and daily inspections of the ponds will be formalised into licence conditions.

8.4.4 Consequence The vegetation in the vicinity of the ponds is salt tolerant and is not considered to be either threatened or priority. The fauna survey also concluded that there are no threatened or priority species within the vicinity of the project area. A 1 in 50 year, 24 hour storm event would dilute the TDS from the spillage of the pond as it dispersed across the playa. As such, the Delegated Officer considers overtopping of the pond may cause Minor and low level local impacts to the playa surface.

8.4.5 Likelihood of consequence The Delegated Officer has considered:  Controls proposed by the Applicant; and  The meteorological data within the area and has determined that minor and short term impacts on surrounding vegetation and biota would Unlikely occur in most circumstances during active operations.

8.4.6 Overall rating The Delegated Officer has compared the consequence and likelihood ratings described above for the Risk Criteria and determined that the overall rating for the risk of the ponds overtopping and emissions impacting on sensitive receptors during active operations is Medium.

8.5 Risk Assessment – Leaks and spills through base of pond and/or pipeline

8.5.1 General hazard characterisation and impact

Normal and Abnormal Operation

During normal operations there will be no emissions via leaks and spills through the base of the pond or from pipeline leaks.

Leaks and spills through the base of the pond and pipeline will only occur during abnormal operations if ruptures were to occur.

Potential impacts from the brine leaking include contamination to the surrounding ecosystem and groundwater due to the high salinity content. However, given the ponds and hose are within the salt lake surface, the impact of brine spillage would be considered minimal. TDS levels within the immediate groundwater is also up to 200 000 mg/L. TDS within the ponds and hose will be up to approximately 200 000 mg/L. A Level 1 Fauna survey was carried out in September 2016. 124 fauna species were recorded, including 23 mammals, 61 birds, 39 reptiles and one frog. No threatened fauna as defined by the Environment Protection and Biodiversity Conservation Act 1999 were identified. Nor were any priority fauna species listed (Australian Potash 2016). The playa surface may provide habitat for ‘salt lake specialist’ invertebrate species such as salt-tolerant species of wolf spiders, tiger beetles, crickets, ants and earwigs (Australian Potash 2016). However, based on information the Applicant has collected, it appears that potential short range endemic (SRE) invertebrates (if present) are unlikely to be restricted to the proposed trial area, given the scale of playa habitat beyond the disturbance footprint. The surrounding vegetation within the playa surface is highly salt tolerant. A Level 2 vegetation survey was carried out in December 2015 and October 2016, with two vegetation communities identified; a dense, low shrub across the lake bed of Tecticornia indica and a forest of Casuarina pauper over open low scrub of Acacia burkittii within the dunes (Australian Potash 2016). Neither of the communities are considered threatened or priority species (Botanica Consulting 2016). There is potential for impacts to occur on the fringing vegetation if the ponds were to seep or the hose were to rupture.

8.5.2 Applicant controls

The Applicant has committed to fully lining the ponds with 1.5 mm HDPE liner or equivalent (PVC/HDPE/EPDM). The liner will be laid in sheets and welded in situ and will be keyed into the berm walls along the top of the crest of the ponds to ensure that the liner doesn’t slip. As the specifications of the liner have not been confirmed, a works approval condition will ensure the liner system will achieve a permeability of 1 x 10-9 m/s.

The pipeline from the bore to the pilot pond is a flat-lay hose. The Applicant has stated the topography of the proposed positioning for the hose is such that any spillage from a rupture will naturally flow back to the playa surface.

8.5.3 Key findings

The Delegated Officer has reviewed the information regarding leaks and spills through the base of the ponds and from the pipeline and has found:

1. Leaks and spills of the brine may impact on surrounding ecosystems due to the high salinity content.

2. Proponent controls of installing and maintaining the liner system will prevent leaking of brine.

3. The positioning of the pipeline means any leaks in abnormal situations will flow straight to the playa surface.

8.5.4 Consequence The vegetation in the vicinity of the ponds is salt tolerant and is not considered to be either threatened or priority. The fauna survey also concluded that there are no threatened or priority species within the vicinity of the project area. As such, the Delegated Officer considers leaks and spills of the pond and/or pipeline may cause Minor and low level local impacts to the playa surface.

8.5.5 Likelihood of consequence

The Delegated Officer has considered:  Controls proposed by the Applicant; and  The fauna and flora types within the area and determined that the likelihood of impacts from leaks and spills on surrounding soils, ecosystems and groundwater will probably not occur in most circumstances. Therefore the Delegated Officer considers the likelihood to be Unlikely.

8.5.6 Overall rating

The Delegated Officer has compared the consequence and likelihood ratings described above for the Risk Criteria and determined that the overall rating for the risk of spills and leaks during active operations to be Medium.

8.6 Summary of risk assessment and acceptability A summary of the risk assessment and the acceptability of the risks with treatments are set out in Table 10 below. Controls are described further in section 9. Table 10: Risk assessment summary

Emission Pathway and Applicant controls Impact Risk Rating Acceptability with Receptor treatment (conditions on Type Source instrument)

1 Brine from Overtopping of Direct discharge Infrastructure Design Vegetation impact Minor consequence Acceptable subject to ponds evaporation ponds to land and regulatory controls infiltration to Visual freeboard Unlikely monitoring Construction beneath the lake Medium risk surface Requirements for the Requirement works approval regarding Operation of Infrastructure Requirements regarding operation of infrastructure and 2 Brine spillage Pipeline leak or monitoring rupture requirements for the licence Liner rupture

9. Determined Regulatory Controls A summary of the risks with corresponding controls are set out in Table 11. The risks are set out in the assessment in section 8 and the controls are detailed in this section 9. Controls will form the basis of conditions in the works approval set out in Attachment 1 and will be used to determine conditions in the subsequent licence. Table 11: Summary of regulatory controls to be applied

Controls

9.1 Infrastructure and 9.2 Specified Action Equipment (works (licence only) approval and licence)

1. Overtopping of evaporation • •

ponds 8)

2. Spills of brine from pipelines or in section in section liner tears and • • overtopping of

ponds Risk items (see risk analysis analysis risk (see items Risk

9.1 Infrastructure and Equipment (works approval and licence)

9.1.1 Leaks, spills and overtopping Infrastructure and Equipment The following environmental controls, infrastructure and equipment should be constructed to prevent and manage the possibility of brine overtopping the ponds at the Premises. The specified infrastructure requirements have been derived from obligations of the Application and are considered necessary to ensure regulatory oversight and outline what has been assessed under the Issued Works Approval.

Infrastructure Requirements (Design and Construction)

All evaporation ponds Lined with HDPE liners and freeboard markers installed

The licence will include conditions regarding the operation of the specified infrastructure and equipment consistent with the controls proposed by the Applicant. 9.2 Specified Action (licence only)

The licence will include a freeboard limit of 500 mm as proposed by the Applicant. Daily monitoring of the freeboard is required to ensure the limit is not breached. There is also a requirement to visually inspection the flat-hose and the integrity of the liner to ensure no leaks or spills have occurred. The Licence Holder should maintain a record of all inspections undertaken. 10. Appropriateness of Works Approval conditions The conditions in the Issued Works Approval in Attachment 1 have been determined in accordance with DER’s Guidance Statement on Setting Conditions.

Condition Ref Grounds Environmental Compliance Environmental compliance is a valid, risk-based Condition 1 condition to ensure appropriate linkage between the works approval and the EP Act. Premises These conditions are valid, risk-based and Conditions 2 and 3 consistent with the EP Act. Location of Works This condition is valid, risk-based and consistent Condition 4 with the EP Act. Infrastructure and Equipment These conditions are valid, risk-based and contain Conditions 5, 6 and 7 appropriate controls (see section 8.1). Records and Information These conditions are valid and are necessary Conditions 8 and 9 administration and reporting requirements to ensure Reports compliance. Conditions 10 and 11 Requests for Information Condition 12 DER notes that it may review the appropriateness and adequacy of controls at any time, and that following a review, DER may initiate amendments to the works approvals under the EP Act. 11. Appropriateness of Licence conditions The conditions in the Issued Licence in Attachment 1 have been determined in accordance with DER’s Guidance Statement on Setting Conditions.

Condition Ref Grounds Environmental Compliance Environmental compliance is a valid, risk-based Condition 1 condition to ensure appropriate linkage between the works approval and the EP Act. Infrastructure and Equipment These conditions are valid, risk-based and contain Conditions 2 and 3 appropriate controls (see section 7). Specified Actions These conditions are valid, risk-based and contain Condition 4 appropriate controls (see section 7). Emissions This condition is valid and is necessary to mitigate Condition 5 unreasonable emissions and to ensure compliance with the EP Act. Information These conditions are valid and are necessary Conditions 6, 7, 8, 9 and 10 administration and reporting requirements to ensure compliance.

12. Applicant’s comments The Applicant was provided with the draft decision report, draft works approval and draft licence on 24 March 2017. The Applicant’s comments were received by DER in writing on 28 March 2017. Appendix 2 contains a summary of the Applicant’s comments and the Delegated Officer’s consideration. 13. Conclusion This assessment of the risks of activities on the premises has been undertaken with due

consideration of a number of factors, including the documents and policies specified in this decision report (summarised in Appendix 1). Based on this assessment, it has been determined that the Issued Works Approval and Issued Licence will be granted subject to conditions commensurate with the determined controls and necessary for administration and reporting requirements.

Tim Gentle Manager Licensing (Resource Industries) An officer delegated under section 20 of the Environmental Protection Act 1986

Appendix 1: Key Documents

Document Title In text reference Availability

1 Application for a Works Approval under DER internal the Environmental Protection Act 1686 (W6002/2016/1), Australian Potash, 21 December 2016

2 Botanica Consulting, Flora and Fauna Botanica DER internal Assessment of the Pilot Pond and Consulting 2016 Turkeys Nest Development Lake Wells Project For Australian Potash Limited, Tenement: E38/2742, December 2016

3 DER Guidance Statement on Decision accessed at Making, November 2016 www.der.wa.gov.au 4 DER Guidance Statement on Environmental Siting, November 2016

5 DER Guidance Statement on Licence duration, August 2016

6 DER Guidance Statement on Regulatory principles, July 2015

7 DER Guidance Statement on Risk Assessments, November 2016

8 DER Guidance Statement on Setting Conditions, October 2015

9 DER Guideline Assessment and management of contaminated sites, Contaminated sites guideline, December 2014

10 Griffiths, S. R. Smith, G. B. Donato, D. B. Griffiths et al., 2009 Available online at: Gillespie, C. G. (2009). Factors http://www.elsevier.com/locate/ influencing the risk of wildlife cyanide ecoenv poisoning on a tailings storage facility in the Eastern Goldfields of Western Australia. Ecotoxicology and Environmental Safety, [online] p. 1583. Available at http://www.elsevier.com/locate/ecoenv

11 Lake Wells Potash Project Pilot Australian Potash DER internal Evaporation Pond Trial – Appendix 3A, 2016 Works Approval application submitted by Australian Potash Limited for the conduct of solar salt production trials on tenement E38/2748, 21 December 2016

Appendix 2: Summary of Applicant’s Comments on Risk Assessment and Draft Conditions

Comments received Delegated Officer consideration of comments

Australian Potash Ltd - Matt Shackleton, 28 The Decision Report has been updated to March 2017 amend the trial period from 6-8 months to 12 months. Therefore, the ‘approved premises  Clarity required for ‘approved premises production or design capacity’ will remain at 20 production or design capacity or tonnes per Annual Period. throughput’ on whether 20 tonnes of potassium salt is permitted for the Annual Period or the trial period (6-8 months).  Trial period to be increased to allow 12 months of evaporation due to high rainfall experienced over summer.

Australian Potash Ltd - Matt Shackleton, 28 Comment accepted and change to document March 2017 made.  Table 3 of the draft licence describes the “authorised works” as “pilot pond complex consisting of 4 ponds” and reference “site plan” as the specification/drawing. For increased certainty, Australian Potash suggests the following definition of the authorised works: ‘Pond complex (comprising 4 ponds), access road and platforms, laydown and topsoil storage areas’.

Australian Potash Ltd - Matt Shackleton, 28 Comment noted and agreed. The intent of the March 2017 Material Change condition was to be an optional condition requested either by the Licence Holder  The draft licence states licence or if DER deems necessary. The Delegated “changes to the site layout and Officer has reviewed the condition specific to infrastructure…” are considered Material this licence and has concluded the condition is Changes. It is Australian Potash’s view not required. The configuration of the ponds will that an increase in the disturbed not change the risk assessment to potential footprint would be a material change but emissions. Hence the Material Change condition modification of the configuration of the has been removed. pond layout is not.  Recent site assessments have suggested a revised layout (per the attached drawing) would improve safety and constructability by avoiding soft ground. The disturbance footprint would not exceed the 0.8 ha area described in our works approval application and would occur at the same location as that shown in the prescribed premises maps shown in Schedules 1 and 2 of the draft works approval. A plan showing the

Comments received Delegated Officer consideration of comments proposed modified pond layout is attached to this letter.  In order to maintain the 8,000 m2 maximum disturbance footprint for the evaporation ponds, while taking advantage of the most suitable foundation conditions at our nominated trial location, the Licence Holder has adapted a pond configuration with slightly higher perimeter embankments in the first two ponds. The maximum proposed embankment height for the revised pond configuration is 1.3 m. The proposed 0.5 m minimum freeboard is unchanged.

Australian Potash Ltd - Matt Shackleton, 28 Table 5 is intended as a regulatory constraint as March 2017 per licence condition 5.  Clarity required regarding Table 5 of Suggested change to remove pond draft licence and whether it is intended specifications has been noted and accepted. to impose regulatory constraint.  Suggestion made to remove pond specifications and include a requirement that the total extent of disturbance is not to exceed 0.8 ha.

Australian Potash Ltd - Matt Shackleton, 28 Noted and accepted. Section 8 in this Decision March 2017 Report has been amended to reflect monitoring changes.  Licence holder has requested the need for inspections of the hose (as specified in condition 7) is limited to the periods when the hose is in active use for filling of ponds, which is a period of less than two weeks.  The Licence Holder has also pointed out there will be limited opportunities to visually inspect the pond liners once they have been installed and commissioned as only the sections of liner above the freeboard zone will be visible.  Suggestions provided to amend the monitoring frequencies to align with practicalities of the operation.

Australian Potash Ltd - Matt Shackleton, 28 Noted and accepted. March 2017  The Licence Holder advised that the Programme of Works submitted to the DMP for the project was approved on 13 March 2017. A copy has been provided to DER.

Comments received Delegated Officer consideration of comments

Australian Potash Ltd - Matt Shackleton, 28 Typographical errors noted and corrected. March 2017 New ‘General Layout’ map noted and accepted.  Some minor typographical errors were noted.  Revised ‘General Layout Plan’ provided.

Attachment 1: Issued Works Approval W6002/2016/1

Attachment 2: Issued Licence L9027/2017/1