Koodaideri Project - der.wa.gov.au

Level 18, Central Park 152-158 St Georges Terrace Perth WA 6000 © Copyright 2018 Rio Tinto

www.worleyparsons.com

RIO TINTO PROJECTS

Koodaideri Project Works Approval - Pelican Camp Waste Water Treatment Plant Supporting Documentation

Licence Amendment Supporting Documentation Works Approval – Pelican Pelican Camp Waste Water Treatment Plant Supporting Documentation

Koodaideri Exploration Pelican Camp – L8562/2011/1

Project No 201012-00702

Document No. KD-9900-H-REP-00006

19 December 2018

DocuSign Envelope ID: A362AAFB-3825-4955-8027-DEC879181642DocuSign Envelope ID: 93972A51-449E-40E9-92E3-C252102B1D78

Koodaideri Project – KD-9900-H-REP-00006

Rev Description Original

Review WorleyParsons

Approval Date

Customer Approval

Date

0 Issued for Use 19-Dec-18 19-Dec-18

D Pearse N Simcock B McLernon J Whitburn

KD-9900-H-REP-00006_0.DOCX

ii

Disclaimer

This report has been prepared on behalf of and for the exclusive use of Rio Tinto Projects, and is subject to and

issued in accordance with the agreement between Rio Tinto Projects and WorleyParsons. WorleyParsons

accepts no liability or responsibility whatsoever for it in respect of any use of or reliance upon this report by any

third party. Copying this report without the permission of Rio Tinto Projects or WorleyParsons is not permitted.


Works Approval – Pelican Camp Waste Water

Treatment Plant Supporting Documentation

Koodaideri Rail Project – L47/810

December 2018


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Disclaimer and Limitation

This report has been prepared by Rio Tinto Iron Ore (Rio Tinto), on behalf of Pilbara Iron Pty

Limited, specifically for the Koodaideri Rail Project. Neither the report nor its contents may be

referred to without the express approval of Rio Tinto, unless the report has been released for

referral and assessment of proposals.

Document Status

Rev Author Reviewer/s Date Approved for Issue

Signed Date

1 Worley Parsons

Sean Savage,

Leisa Turner 19/12/2018


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TABLE OF CONTENTS

Disclaimer ............................................................................................................................. 2

1 Licensee Information ............................................................................................ 1

1.1 Occupier Details ...................................................................................................... 1

2 Premises Details .................................................................................................... 2

2.1 Prescribed Activity Overview ................................................................................... 2

2.2 Legal Land Description ............................................................................................ 2

2.3 Location and Siting .................................................................................................. 2

2.4 Topography ............................................................................................................. 9

2.5 Water Resources ..................................................................................................... 9

2.6 Hydrogeology .......................................................................................................... 9

2.7 Geology ................................................................................................................... 9

2.8 Fauna .................................................................................................................... 10

2.9 Vegetation and Flora ............................................................................................. 10

2.10 Stakeholder and Community Consultation ............................................................. 10

3 Prescribed Premises Category ........................................................................... 13

3.1 Current Environmental Protection Act 1986 (Part V) Licences / Works Approvals . 13

3.2 Other Approvals / Licences ................................................................................... 13

4 Process Description ............................................................................................ 15

4.1 Overview ............................................................................................................... 15

4.2 Design and Operation ........................................................................................... 16

4.3 Timescale for Construction / Operation ................................................................. 19

4.4 Commissioning and Reporting ............................................................................... 19

4.5 Inspection and Servicing ....................................................................................... 20

5 Risk Identification and Assessment .................................................................. 20

6 Emission Management ........................................................................................ 25

6.1 Air Emissions (not including dust) .......................................................................... 25

6.2 Dust Emissions ..................................................................................................... 25

6.3 Noise Emissions .................................................................................................... 26

6.4 Odour Emissions ................................................................................................... 26

6.5 Light Emissions ..................................................................................................... 26

6.6 Discharge to Water ................................................................................................ 27

6.7 Discharges to Land ............................................................................................... 27

6.8 Hydrocarbon and Chemical Storage ...................................................................... 31

6.9 Solid/Liquid Waste ................................................................................................. 33

6.10 Flora and Fauna .................................................................................................... 33

7 Monitoring ............................................................................................................ 34


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8 Rehabilitation and Closure ................................................................................. 35

9 Project Costs ....................................................................................................... 35

10 Summary of Commitments ................................................................................. 36

Appendix A Drawings ................................................................................................ 39

Appendix B Photographs – Typical Plant Layouts .................................................. 44

TABLES

Table 2-1 Coordinates (MGA Zone 50) of Pelican Camp WWTP and Sprayfield Proposed Prescribed Premises Boundary ........................................................................... 4

Table 2-2 Sensitive Land Uses and distance from prescribed activity ................................... 7

Table 2-3 Specified ecosystems ........................................................................................... 8

Table 2-4: Other landscape features, relevant factors or receptors ....................................... 8

Table 3-1 Prescribed Premises Category ............................................................................ 13

Table 5-1: Risk Rating Matrix ............................................................................................. 20

Table 5-2: Consequence Matrix ......................................................................................... 21

Table 5-3: Likelihood Matrix ............................................................................................... 21

Table 5-4: Risk Assessment .............................................................................................. 23

Table 6-1: Department of Water, Water Quality Protection Note 22- nutrient loading rates . 28

Table 6-2 Expected raw sewage loading rates .................................................................... 29

Table 6-3 NWQMS, Water Quality Discharge Criteria ......................................................... 30

Table 6-4 Proposed environmental controls ........................................................................ 30

Table 6-5 Proposed environmental controls ........................................................................ 32

Table 7-1 WWTP water quality monitoring requirements ..................................................... 34

Table 9-1: Project Costs ...................................................................................................... 35

FIGURES

Figure 2-1 Koodaideri Mine and Rail Project Location Context .............................................. 3

Figure 2-2 Prescribed Premises location in relation to sensitive receptors ............................ 5

Figure 2-3 WWTP and associated sprayfield locations at L47/00810 .................................... 6

Figure 2-4 Soils mapped in L47/00810 by Agriculture Western Australia (1967) ................. 12


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Abbreviations

AHA Aboriginal Heritage Act 1972

BOD Biological Oxygen Demand

Pelican Pelican Rail Camp

CEMP Construction Environmental Management Plan

COMPANY Any or all of Rio Tinto entities including Rio Tinto Iron Ore, Rio Tinto Projects, Growth & Innovation (Iron Ore), Mt Bruce Mining, Hamersley Iron and other wholly owned companies

DMIRS Department of Mines, Industry Regulation and Safety

DWER Department of Water and Environmental Regulation

EPA Environmental Protection Authority

EPAS EPA Services (branch of DWER)

EPCM Engineering, Procurement and Construction Management

GWL Groundwater Water Licence

HI Hamersley Iron

HSEQMS Health Safety Quality and Environment Management System

JHA Job Hazard Analysis

MBR Membrane Bioreactor

MS Ministerial Statement

MTPA Million tonnes per annum

NWQMS National Water Quality Management Strategy

OEPA Office of the EPA

P2 Priority 2 Public Drinking Water Source Area

PDWSA Public Drinking Water Source Area

PER Public Environmental Review

PI Pilbara Iron

Project Koodaideri Iron Ore Mine and Infrastructure Project

RTIO Rio Tinto Iron Ore

WA Works Approval

WWTP Waste Water Treatment Plant


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1 Licensee Information

1.1 Occupier Details

The occupier (the Licensee) of the land subject to this Works Approval application is:

Pilbara Iron Pty Ltd

Level 18, Central Park

152-158 St Georges Tce

Perth WA 6000

ACN: 107 210 248

The proposed works are being undertaken in the Shire of Ashburton.

The contact person for the Works Approval application is as follows:

Sean Savage

Superintendent Government Approvals

Rio Tinto

Level 18, Central Park

152-158 St Georges Terrace

Perth WA 6000

Telephone: T: +61 (0)8 6213 1254 M: +61 (0)467 776 204

Email: [email protected]


mailto:[email protected]

mailto:[email protected]

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2 Premises Details

2.1 Prescribed Activity Overview

This works approval application is for the construction of a hired wastewater treatment plant and sprayfield (WWTP) at the proposed Pelican Rail Camp (Pelican), adjacent to the Rio Tinto Dampier-Tom Price rail line approximately 70 km north of Tom Price.

Pelican Camp will provide offices and accommodation for approximately 200 personnel during the construction phase of the Koodaideri rail spur.

The proposed WWTP has a design capacity of 74 cubic metres per day. It is estimated that the WWTP will be in operation for approximately 18 months, however, this timeframe may be extended to meet changes in the construction schedule or proponent requirements.

2.2 Legal Land Description

Pelican Camp will be located within the Shire of Ashburton on Miscellaneous Licence L47/00810 held by Hamersley Iron Pty Limited.

Pilbara Iron Pty Ltd (a subsidiary of Rio Tinto) provides the operation, maintenance and management of construction works associated with the port, rail and power assets of Hamersley Iron. Pilbara Iron Pty Ltd is therefore the occupier for any licences or permits required under the Environmental Protection Act 1986 for the KRP.

2.3 Location and Siting

2.3.1 Location Context

Pelican Camp will be located approximately 70 km north of Tom Price and 150 km north of Paraburdoo within the inland Pilbara region of northern Western Australia. The Pelican Camp location within a regional context is shown in Figures 2-1 and 2-2, with the layout and WWTP facility shown in more detail in Figure 2-3.

The proposed WWTP and sprayfield are located approximately 30 km to the north-west of the Karijini National Park (KNP), and will have a combined total footprint area of up to approximately 3 ha within Hamersley Iron Miscellaneous Licence L47/00810.


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Figure 2-1 Koodaideri Mine and Rail Project Location Context


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The approximate boundary coordinates of the proposed Pelican Camp WWTP and sprayfield proposed prescribed premises boundary are shown below in Table 2-1.

Table 2-1 Coordinates (MGA Zone 50) of Pelican Camp WWTP and Sprayfield Proposed Prescribed Premises Boundary

ID Easting (m) Northing (m)

1 572,868 7,558,248

2 572,871 7,558,692

3 572,877 7,560,178

4 573,409 7,559,580

5 573,795 7,558,620

6 573,927 7,558,294

7 573,935 7,558,272

8 573,933 7,557,775

9 573,057 7,557,779

10 572,984 7,557,961

11 572,868 7,558,248


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Figure 2-2 Proposed prescribed premises boundary location in relation to sensitive receptors


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Figure 2-3 WWTP and associated sprayfield locations and proposed prescribed premise boundary at L47/00810


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2.3.2 Sensitive Land Uses

The distance to residential and sensitive receptors are detailed in Table 2-2. The closest

residential area to the premises is the township of Tom Price (70 km to the south) shown in

Figure 2-2 which had a population of 3,005 in 2016 (Australian Bureau of Statistics, 2016).

The WWTP sprayfield is 700 m north-west of the accommodation rooms at Pelican Camp.

Table 2-2 Sensitive Land Uses and distance from prescribed activity

Sensitive Land Uses Distance from Prescribed Activity

Closest residential zoned premises: Tom

Price

(Zoned residential Shire of Ashburton

Planning Scheme No. 7)

Approximately 70 km to the south of the

WWTP

Closest recreation zoned premises: Tom

Price

(Zoned residential Shire of Ashburton

Planning Scheme No. 7)

Approximately 70 km to the south of the

WWTP

Karijini National Park (north western most

point)

Approximately 35 km to the south-east of the

WWTP

Millstream Public Drinking Water Source

Area

Located at the eastern edge, 4 km inside the

boundary of Millstream Public Drinking Water

Source Area Priority Zone 2

Exploration & Mining Camps Approximate distances to the WWTP:

FMG Bonnie Doon Camp – 19 km west south-

west

FMG The Castle Camp – 19 km south-east

FMG Ellie Camp – 19 km south-east

Coolawanyah Pastoral Lease L3114/1228

Homestead

Approximately 25 km north-west of the WWTP


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2.3.3 Specified Ecosystems

The distances (within a 30km radius) to specified ecosystems are shown in Table 2-3.

Table 2-3 Specified ecosystems

Specified ecosystems Distance from Prescribed Premises

Parks and Wildlife tenure No Parks and Wildlife tenure is located within

a 30km radius of the WWTP.

Public Drinking Water Source Area

(PDWSA)

The proposed WWTP is located 4 km inside

the eastern boundary of the Millstream

PDWSA.

RAMSAR wetland – Fortescue Marsh More than 30km to the south-east of the

WWTP

Geomorphic Wetlands No geomorphic wetlands are located within a

30km radius of the WWTP

Threatened Ecological Communities and

Priority Ecological Communities –

Themeda Grasslands of Hamersley

Station

‘Themeda Grasslands of Hamersley Station’

Threatened Ecological Community is situated

approximately 20 km to the south of the study

area.

Declared Rare Flora There is one population of Priority 2

Gompholobium karijini within 30m of the

Premises south east boundary. No activity is

expected within >135 m of this population.

2.3.4 Other environmental receptors

Other environmental receptors relevant to the WWTP are provided in Table 2-4.

Table 2-4: Other landscape features, relevant factors or receptors

Other receptors or areas of concern Location

Groundwater The WWTP is located in an area where depth to

groundwater is greater than 25m.

Surface water (Weelumurra Creek) Weelumurra Creek is the closest water course

and is > 800m from the proposed camp, on the

other side of the Rio Tinto mainline.


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2.4 Topography

The proposed WWTP is located within the Hamersley subregion of the Pilbara bioregion,

which is described as follows:

“Mountainous area of Proterozoic sedimentary ranges and plateaus, dissected by gorges (basalt, shale and dolerite). Mulga low woodland over bunch grasses on fine textured soils in valley floors, and Eucalyptus leucophloia over Triodia brizoides on skeletal soils of the ranges. The climate is semi-desert tropical, average 300 mm rainfall, usually in summer cyclonic or thunderstorm events. Winter rain is not uncommon. Drainage into either the Fortescue River (to the north), the Ashburton River to the south, or the Robe River to the west. Subregional area is 6,215,092 ha” (Kendrick 2003).

2.5 Water Resources

The proposed WWTP is located within a large expanse of almost flat plains intersected by small drainage channels. There are no significant watercourses in the development area, with a single moderate-sized creek line present in the northern half of the tenement as shown in Figure 2-3. No permanent or semi-permanent water bodies are present.

Groundwater abstraction bore WB18KRP0014 has been established at the site and will provide construction and potable water requirements for Camp. The groundwater table lies approximately 25 metres below ground level. The proposed sprayfield is located approximately 500 m from the potable water bore.

2.5.1 Public Drinking Water Source Protection Area

The proposed WWTP is located 4 km inside the eastern boundary of the Priority 2 (P2) outer

Catchment area of Millstream Water Reserve.

2.6 Hydrogeology

The proposed WWTP is located within the Lower Fortescue River catchment. The Lower Fortescue River flows in a generally westerly direction and the catchment is bounded by the Chichester Range to the north, Hamersley Range to the south and the Goodiadarrie Hills to the east. These major features lie along an east-west alignment and rise up from the coastal plains to the west.

Within the proposed Camp, groundwater is not encountered within the alluvials due to their shallow nature (~20m thick). The Camp water supply bore targets the bedrock aquifer of the Wittenoom Formation. The aquifer is recharged by rainfall at outcrop and leakage from the overlying Alluvial Aquifer.

The existing water supply bore at the Camp location is fresh with a TDS of 636 mg/l and pH 7.92.

2.7 Geology

Two soil units have been mapped by Agriculture Western Australia (1967) within tenement L47/00810. The dominant soil unit comprises 98.5% of the tenement and is classified as Fb3 – High level valley plains set in extensive units of Fa13, stony and shallow soils. The dominant soils are deep earthy loams coexisting with small areas of sandy loams (Figure 2-4).


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2.8 Fauna

A detailed assessment of flora and fauna has been completed. The survey by Biota (2018) concluded that the fauna habitat found within the Pelican Camp study area is ubiquitous in the Pilbara bioregion, and as such would not be considered under threat by the proposed works. No conservation significant vertebrate fauna species were recorded during the survey.

2.9 Vegetation and Flora

The survey by Biota (2018) identifies four vegetation units within three broad landform categories – Stony plains, Low hills and Minor creeklines.

Vegetation associated with Stony Plains is the predominant unit throughout the study area, covering 97.2% of the area. Vegetation unit P1 dominates the area covering 80.2% and consists of scattered low trees (Corymbia hamerseyana and Eucalyptus leucophloia subsp. leucophloia) over Acacia atkinsiana, A ancistrocarpa open shrubland over Triodia epacita, T. wisena open hummock grassland.

Vegetation unit P2 covers the remaining 17% of the Stony Plains consisting of Corymbia hamerseyana, (Eucalyptus leucophloia subsp. leucophloia) scattered low trees over E. gamophylla low open mallee woodland over Acacia ancistrocarpa (A. bivenosa) open shrubland over A. spondylophylla low open shrubland over Triodia epacita, open hummock grassland.

Vegetation unit P2 supports one population of the Priority 2 Gompholobium karijini, however this unit is not considered to be representative of the typical vegetation supporting large populations of the Priority 2 flora species. All vegetation units in the study area are considered to be well represented in the locality.

The remaining vegetation is associated with Low hills and narrow drainage lines covering 2.8% of the lease area. No threatened flora species were recorded during surveys of tenement.

There are no Threatened Ecological Communities (TECs) pursuant to Schedule 2 of the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) within the tenement. The nearest environmentally sensitive area is the Threatened Ecological Community (TEC) – ‘Themeda Grasslands of Hamersley Station’ 20 km south southeast of the proposed Pelican Camp location.

2.10 Stakeholder and Community Consultation

2.10.1 Department of Water and Environmental Regulation (DWER)

Meetings were held in August and September 2018 with the DWER – Regulatory Services Environment branch and the DWER - Water branch to discuss the proposed Pelican rail construction camp given its location within the Millstream Water Reserve – Priority 2.

The proposed secondary approval applications under the Rights in Water and Irrigation Act 1914, Part V of the Environmental Protection Act 1986 and the Mining Act 1978 were discussed. During the meeting the proposed location, set out, management and purpose of the Camp were outlined. It was discussed that the Departments WQPN’s and Millstream Water Reserve – Drinking Water Source Protection Plan – June 2010 will be complied with. DWER - Water requested that the Water Corporation be advised of the meeting and the outcomes of the discussion. This was done so via an email to the Water Corporation dated 21 August 2018.

2.10.2 Community Consultation

The Company has a long-term commitment to working with Pilbara communities and recognises that local communities have a direct interest in their activities.


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Substantial stakeholder consultation and public review of the proposed activities has occurred historically, as part of environmental approval processes for the Koodaideri Iron Ore Project, including development of an Access and Consent Deed for Project activities in and around the Coolawanyah Pastoral Lease. The Company has sought to keep relevant stakeholders informed in relation to future mining activities in the area.

The WWTP development is not expected to directly affect any communities and therefore no specific community consultation has been undertaken. The Shire of Ashburton and the Department of Health will be consulted as required for approvals associated with the construction, installation and operation of the WWTP. No further consultation is expected to be undertaken with specific reference to WWTP.

2.10.3 Aboriginal Heritage

The Camp is located within the traditional lands of the Yindjibarndi People. The identification and management of cultural heritage within the traditional lands of the Yindjibarndi People is in accordance with the principles and practices outlined within Rio Tinto’s Communities and Social Performance Guidelines, the Rio Tinto Cultural Heritage Group Procedure, and the heritage protocol within the Yindjibarndi People Claim Wide Participation Agreement (CWPA).

Extensive heritage surveys have been conducted in and around the development area. No heritage sites will be impacted during the construction or operation of the WWTP.


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Figure 2-4 Soils mapped in L47/00810 by Agriculture Western Australia (1967)


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3 Prescribed Premises Category

The proposed facility is considered a prescribed premises as defined by Schedule 1 of the

Environmental Protection Amendment Regulations 1987.

Table 3-1 Prescribed Premises Category

3.1 Current Environmental Protection Act 1986 (Part V) Licences / Works Approvals

There are presently no Part V licences or works approvals in place for the Camp location or

tenement.

The following documents were issued to/by the WA Office of the Environmental Protection

Authority (EPA) and have relevance to this proposal:

Koodaideri Mine and Infrastructure Project PER (EPBC Referral Number 2012/6422).

Ministerial Statement 999 (EPA Report 1933).

3.2 Other Approvals / Licences

3.2.1 Part IV of the Environmental Protection Act 1986

Background

Rio Tinto referred a proposal to the Environmental Protection Authority (EPA) on 28 May 2012

to develop and operate an open pit iron ore mine, rail corridor and associated infrastructure at

Koodaideri.

The level of assessment was set by the EPA as a PER. The PER was reviewed by the EPA

and the Report and Recommendations of the EPA (EPA Report 1533) were submitted to the

Minister for Environment for approval. Approval was granted through Ministerial Statement

999 on 10 March 2015 for the project to be implemented.

The proposal was also referred to the former Department of Sustainability, Environment,

Water, Population and Communities (DSEWPaC) (now the Department of Environment and

Category

number

Category Description Category Premises

Production or

Design Capacity

85 Sewage facility: premises – (a) on which sewage is treated

(excluding septic tanks); or (b) from which treated sewage is

discharged onto land or into waters

More than 20 but

less than 100 cubic

metres per day

74 cubic metres

per day


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Energy) for consideration under the Commonwealth Environment Protection and Biodiversity

Conservation Act 1999 (EPBC Act) on 5 June 2012. DSEWPaC determined that the proposal

was a ‘controlled action’ and subject to a bilateral assessment coordinated by the Government

of WA. The proposal was approved under the EPBC Act on 9 May 2015 through instrument

reference EPBC 2012/6422.

Ministerial Statement 999

Ministerial approval was granted 10 March 2015 under Ministerial Statement 999 to construct

and operate an iron ore mining area and associated infrastructure at Koodaideri. This included

the construction and operation of a rail corridor, high voltage power transmission line, airstrip

and accommodation facilities.

Relevant to Part V of the Environmental Protection Act 1986, EPA’s assessment (EPA Report

1533) determined that the impacts from the Project could be adequately managed and issued

Ministerial Statement 999 with conditions to ensure that:

(a) The proposal is implemented in a manner that maintains the Pilbara Leaf-nosed

Bat colony which resides within the K75W adit / cave system;

(b) Troglofauna are protected by excluding mining and infrastructure placement within

a portion of troglofauna habitat;

(c) Mine construction and operational activities are carried out in a manner that

minimises impacts to the Northern Quoll;

(d) Mining and infrastructure is sited in a manner that avoids the Declared Rare Flora,

Hamersley Lepidium;

(e) The proposal is implemented so that it does not affect the viability of the Priority 1,

Sauropus sp. Koodaideri detritals; and

(f) Mining activities do not impact the hydrological regime or water quality of the

Koodaideri Spring Gorge.

Conditions relating the management of asbestos related risk are relevant to the construction

of the Rail corridor through the Wittenoom Asbestos Management Area and are not directly

relevant to the Camp and WWTP construction.

3.2.2 Rights in Water and Irrigation Act 1914

A licence to abstract groundwater under Section 5C of the Rights in Water and Irrigation Act

1914 has been applied for from the Department of Water and Environmental Regulation –

Water branch. The abstraction limit for the proposed groundwater licence is 70,000 kL/annum

for potable supply and general camp purposes.

3.2.3 EP Act Part V Clearing

A Native Vegetation Clearing Permit (NVCP) has been submitted to the Department of Mines,

Industry Regulation and Safety for the development of the camp and WWTP.


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3.2.4 Mining Act 1978

The development of the Camp and WWTP is subject to a Mining Proposal that has been submitted to DMIRS.

3.2.5 Local Government and Department of Health Approvals

The development of the Camp and WWTP are subject to the Local Government and

Department of Health approvals:

Building Permit applications to be submitted to the Shire of Ashburton for construction

of the Camp; and

An application to the Shire of Ashburton (and subsequently referred to the Department

of Health) for approval of the WWTP.

4 Process Description

4.1 Overview

The proposed works comprise the construction, installation and commissioning of a WWTP

capable of treating up to 74 kL/day of wastewater, and a spray irrigated evaporation area for

treated effluent disposal. This infrastructure is required to service the proposed Pelican Camp

that will provide accommodation and associated facilities for up to 200 personnel.

The construction of the WWTP will comprise the following elements:

A WWTP constructed within an approximately 20m x 20m (0.04ha) footprint, entirely

contained within an earthen bund; and

A fenced spray evaporation area with approximate dimensions of 140 m x 150 m (2.1

ha).

The WWTP is a pre-fabricated skid mounted system that will be installed and plumbed in a

single stage.

Hydrocarbons will be stored on site during the Camp and WWTP construction and operation

in 2 x 28 kL double skinned, self-contained storage and dispensing tanks. A typical double

skinned tank similar to the proposed installation at Pelican Camp is shown in Appendix B.

Minor chemical storage facilities will be located on site typically containing a range of

packaged chemicals in 50 litre container, 220L drums and 1000L pods.

A light-vehicle wash down facility will also be located within the vicinity of the diesel storage

and refuelling facility and WWTP.


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4.1.1 Water Supply

Water will be sourced from a single bore constructed and licensed under the Rights in Water

and Irrigation Act 1914. The water supply requirements additional to sewage water input are

expected to be minimal. Water required during construction will be supplied from appropriately

licensed bores within the Project area.

4.1.2 Power Supply

Power supply for the WWTP will be provided from the generators installed to service the

overall Camp power requirements.

4.1.3 Hazardous Materials

Hydrocarbons and chemicals will be used and stored on site during the Camp and WWTP

construction and operation. This includes diesel (2 x 28kL double skinned tanks), small

quantities of lubricants (new and used oil), small quantities of hydraulic fluids, and

maintenance chemicals used for the WWTP operation including liquid sodium hypochlorite

(for disinfection of treated effluent), small volumes of citric acid and hydrogen peroxide (for

membrane cleaning and disinfection).

The diesel storage and refuelling facility, will include high-flow and low-flow refuelling bowser

and fuel management system. The diesel storage will be located adjacent to the main park-

up hardstand and will also have a direct above ground connection to the Camp diesel power

generation facility.

4.1.4 Transport

There will be no additional demand on current transport infrastructure associated with the

installation of the new WWTP.

4.1.5 Visual Impacts

There will be negligible additional visual impact associated with the installation of the new

WWTP.

4.2 Design and Operation

4.2.1 Facility Overview

The proposed WWTP is an aerobic biological treatment plant based on an activated sludge

process with a Membrane Bioreactor (MBR) system as tertiary treatment. The treated effluent

will be transferred to a holding tank for spray irrigation onto an evaporation spray field.

The WWTP will have a design capacity capable of servicing 200 persons. A maximum average

dry weather flow of 74 m3/day is anticipated.


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The WWTP General Arrangement drawings and a Process Flow Diagram are attached as

Appendix A. Typical arrangement photographs are shown in Appendix B.

4.2.2 Sewage Collection

Raw sewage will be collected and transferred to the WWTP via a sewer system operating

under gravity flow to sewage pits. Macerator pumps deliver sewage from these pits directly

into the WWTP balance tanks.

Elevated vent pipes will be included at buildings and pumping stations, in accordance with

Water Services Licensing (Plumbers Licensing and Plumbing Standards) Regulations 2000

and AS/NZS 3500.2:2003 to ensure sewage odours are suitably vented to the atmosphere.

4.2.3 Balance Tanks

Influent sewage reports directly to the balance tanks. Two balance tanks are provided to cover

the required hydraulic load capacity.

Level sensors in the balance tanks control the flow of wastewater to the treatment plant and

minimise any risk of over flow. The balance tanks provide sufficient storage capacity to control

the maximum flow during morning and evening peak times and will manage the surge to

provide the treatment plant with a continuous feed throughout the day.

An aeration system is included in the balance tanks to achieve a good mixing of the raw

sewage and to avoid anaerobic activity in these tanks. Aeration is continued for short periods

of approximately 1 to 2 minutes to avoid introducing high level of oxygen to the next stage of

the treatment process.

4.2.4 Balance Tank Transfer Pump

The balance tank transfer pump is used to transfer sewage from balance tank to the bio-

selector tank. Level sensors maintain the desired levels in the bio-selector tank by actuating

and terminating the Balance Transfer Tank Pump which transfers the influent sewage.

4.2.5 Bio-selector tank

The bio-selector tank represents the first step of the biological process, and provides mixing

of the recycled mixed liquor with fresh feed from the balance tank. An anaerobic process

takes place in the bio-selector tank due to the anoxic condition of the tank. Denitrification

bacteria commence nitrogen removal in this stage.

Feed from the balance tank and mixed liquor return line to the bio-selector tank are introduced

into the bottom of the bio-selector tank while the outlet to the anoxic tank is from the top of the

bio-selector tank. The bio-selector tank is designed to allow over flow directly into the anoxic

tank via two gravity overflow pipes.


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4.2.6 Anoxic Tank

The anoxic process started in the bio-selector tank continues in the anoxic tank. It is

dominated by anaerobic bacteria that reduce biological oxygen demand (BOD) and nitrogen

level. The anoxic tank is equipped with a circulation system providing continuous mixing of the

tank content through the bio-selector tank. At this stage the biological phosphorous and

nitrogen removal takes place. The feed pipe to the anoxic tank provides a vortex mixing motion

to increase mixing efficiency.

The outlet of the anoxic tank is connected to the first aeration tank via a gravity pipe. Water

level in the anoxic tank is maintained by a level sensor that ensures the required retention

time in the anoxic tank is met, maximising nitrogen removal.

4.2.7 Aeration Tanks

Effluent from the anoxic tank flows into the aeration tanks, where phosphorous removal,

ammonium oxidation and carbonaceous removal take place. The aeration tanks are

connected in a series to allow gravity flow from the first to the second tank.

The aeration tanks are equipped with air blowers to provide the biological process with the

required oxygen and to keep the content in suspension. Coarse bubble diffusers, which are

installed at the bottom of each of the aeration tanks, provide stable and homogenous oxygen

transfer into the mixed liquor at a constant mixing velocity.

The environment in the aeration tanks is rich with dissolved oxygen, and provides the best

conditions for bacteria and single-cell organisms to degrade the dissolved organic and

ammonium substances in the sewage and convert them into carbon dioxide and nitrates. This

environment also allows the system to better survive disruption or shock to the treatment

system from changed inflow water chemistry.

4.2.8 Membrane System

The membrane system is a submerged ultra filtration module made of robust polyethylene flat

plates covered on both sides with ultra filtration membranes has pore sizes of approximately

0.04 μm. Passing treated effluent through the membrane ensures high-quality treated water

that is of particles and bacteria.

The membrane housing is fitted with a series of tube diffusers that continuously supply air

bubbles to the membrane surface. The air bubbles have a continuous self-cleaning effect on

the membrane surface, reducing the consumption of chemicals during membrane cleaning.

The concentrated bio-solid (mixed liquor) rejected by the filters is returned to the BioSelector

tank via the mixed liquor pumps. Excess bio-solids are wasted to the sludge tank. Permeate

from the membrane system is transferred to the final holding tanks.

4.2.9 Final Effluent Control

Chemical dosing for disinfection and pH control occurs in the final effluent holding tank.


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4.2.9.1 Chlorine Disinfection System

The chlorine disinfection system consists of a sodium hypochlorite dosing pump, chemical

storage tank and on-line chlorine measuring and control system. Chlorine level will be

maintained between 0.2 mg/L and 0.5 mg/L.

4.2.9.2 pH Control System

The final holding tank is equipped with a pH measuring system that maintains the pH range

between 6.5 and 8.5. Under normal operating conditions, the final effluent pH value will sit

within this range however, a chemical dosing system is provided in case of the need for pH

adjustment.

4.2.9.3 Final Effluent Storage

In the event of wet weather, the final treated effluent will be held in wet weather storage tanks.

Three days of storage capacity is provided.

4.2.10 Sludge Tank

Waste sludge will be collected in a sludge tank. When the settled sludge level in the sludge

tank reaches a set point a tanker truck will be used to remove the sludge from the system for

offsite disposal.

4.3 Timescale for Construction / Operation

It is anticipated WWTP installation will commence and be completed during Q2 2019.

Commissioning activities will begin immediately upon the completion of construction and will

be completed in early Q4 2019.

4.4 Commissioning and Reporting

It is requested that commissioning of the WWTP be undertaken over a 6 month

commissioning period under the works approval and after submission of a compliance

document. This will allow for a registration (as discussed with DWER during project scoping

meetings) to be obtained prior to operation.

Specific tasks that will be undertaken during the commissioning phase include:

Testing for leaks on tanks and piping;

Establishing tank operation levels;

Instrument setting and operations;

Fluid transfer between tanks;

Testing of irrigation equipment;

Complete automatic operation of process;

Testing of safety systems;

Alarms, setting and priming of chemical metering pumps; and

Testing of electrical and mechanical installation.


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On start-up, the WWTP will be filled with water to ensure that effluent discharges are diluted

until system stabilisation.

Monthly samples will be collected during the commissioning period from the final treated

effluent and compared with targets stated in this application in Table 6-3.

Once commissioning is completed, quarterly monitoring of the water quality of the effluent will

be undertaken as per the requirements of Table 7-1.

4.5 Inspection and Servicing

Regular (daily and weekly) inspection, quarterly sample collection and quarterly servicing will

be undertaken to ensure the WWTP is functioning adequately.

4.5.1 Membrane fouling and cleaning

Membrane cleaning is required for operational consistency and maintenance of performance.

Chemical and mechanical cleaning is scheduled to minimise the consumption of cleaning

chemicals and process interruption in order to optimise membrane performance.

Hydrogen peroxide, citric acid and sodium hypochlorite are used for MBR cleaning. The design includes two membrane systems which allows for continuous operation of the treatment plant during this cleaning process. The two systems work independently and can be isolated for chemical cleaning without interruption of the treatment continuity.

5 Risk Identification and Assessment

A risk assessment has been prepared to identify the potential emissions from the proposed

activities and the potential sources, pathways and receptors of those emissions, and proposed

controls to manage potential emissions to determine a risk rating. The risk assessment has

been based on the DWER Guidance Statement: Risk Assessments (released by the then

named Department of Environmental Regulation in 2017) and the Rio Tinto risk assessment

process, based on the following risk rating matrix (Table 5-1):

Table 5-1: Risk Rating Matrix

Consequence

Likelihood 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


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Risk = consequence x likelihood

The following criteria (DWER 2017) are used to determine the consequence and likelihood of

a risk event occurring (Table 5-2 and

Table 5-3).

Table 5-2: Consequence Matrix

Consequence Consequence description

Environment Health

Severe

On-site impacts: catastrophic

Off-site impacts (local scale): high level

Off-site impacts (wider scale): mid level

Mid to long term or permanent impact to an

area of high conservation value or special

significance

Loss of life

Adverse health effects: high level or

ongoing medical treatment

Local scale impacts: permanent loss of

amenity

Major

On-site impacts: high level

Off-site impacts (local scale): mid level

Off-site impacts (wider scale): low level

Short term impact to an area of high

conservation value or special significance

Adverse health effects: mid level or

frequent medical treatment

Local scale impacts: high level impact to

amenity

Moderate

On-site impacts: mid level

Off-site impacts local scale: low level

Off-site impacts wider scale: minimal

Adverse health effects: low level or

occasional medical treatment

Local scale impacts: mid level impact to

amenity

Minor

On-site impacts: low level

Off-site impacts (local scale): minimal

Off-site impacts (wider scale): not

detectable

Local scale impacts: low level impact to

amenity

Slight On-site impacts: minimal Local scale impacts: minimal impacts to

amenity

Table 5-3: Likelihood Matrix

Likelihood Likelihood description

Almost certain The risk event is expected to occur in most circumstances.

Likely The risk event will probably occur in most circumstances.

Possible The risk event could occur at some time.

Unlikely The risk event will probably not occur in most circumstances.

Rare The risk event may only occur in exceptional circumstances.

The potential emissions, sources, pathways and receptors that have been identified for the

construction, commissioning and operation of the proposed WWTP are outlined in Table 5-4.


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This table also identifies the potential impacts, proposed controls and associated risk ratings.

A detailed risk assessment will be undertaken for any activity which has been identified as

having a ‘Medium’ risk rating or higher (Section Error! Reference source not found.).

Detailed risk assessment includes:

A description of the potential emissions, sources, pathways and receptors.

Any controls that have been identified for the risk event.

An assessment of the consequence and likelihood.

Risk rating.


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Table 5-4: Risk Assessment

Source Potential

Emissions Pathway Potential Receptors Potential Impacts Proposed Controls Consequence Likelihood Risk Rating

Detailed Assessment

Required?

Category 85:

Sewage

Facility

Construction of

the WWTP

Dust Air: windborne particulate

(dust) emissions generated

during construction activities

including clearing and vehicle

movements.

Residential: None, other than

the proposed camp, the

nearest town is 70km south

of the WWTP

Health and amenity: None,

given the distance to the

nearest receptor, dust

emissions are not expected

to affect health or amenity.

Dust emissions will be managed as per standard

operating procedures, including:

- clearing during construction will be restricted to

only areas required for construction activities;

- dust suppression (water trucks, control of vehicle

movements / restricted speeds) during

construction; and

- rehabilitation of disturbed areas.

Standard management procedures are expected to

effectively mitigate the risk of dust emissions.

Minor Rare Low Risk pathway is low, detailed

assessment is not required.

However, further detail on

controls provided in Section 6.2d

Terrestrial ecosystems:

Vegetation, including

vegetation communities of

elevated conservation

significance adjacent to the

Premises.

Declining health of vegetation

including reduced ability for

photosynthesis due to dust

deposition / smothering.

Studies examining the

impacts of dust on plant

health in semi-arid

environments found that the

Pilbara environment is

naturally dusty with wind-

blown dust a significant

contributor to ambient dust

levels in the region, hence,

native vegetation is expected

to be reasonably tolerant to

dust deposition.

Noise Air: windborne noise

emissions generated during

construction activities

including vehicle movements.




of the WWTP



nearest receptor, noise



Controls include:

- fitting vehicles and stationary items of equipment

with exhaust mufflers;

- screening or enclosing stationary items of

equipment with acoustic enclosures to reduce

operating noise levels;

- construction works carried out in accordance with

Section 6 of Australian Standard 2436-1981

“Guide to Noise control on Construction,

Maintenance and Demolition Sites” and the

Environmental Protection (Noise) Regulations

1997 (WA).




controls provided in Section 6.3

Operation of

the WWTP

Odour Air: windborne odour

emissions generated during

operation of the WWTP




of the WWTP



nearest receptor, noise



The WWTP will be appropriately designed and

operated to mitigate the risk of odour emissions.

Inspection and maintenance will be undertaken.

Standard maintenance procedures are expected to

effectively mitigate the risk of odour emissions.





Light Air: light emissions generated

during construction activities.

None Operation hours will be 24/7.

Light emissions will be

minimal during operation.

Lighting limited to the minimum required for safe

operations in accordance with Australian standards.





Raw sewage Discharge to land: sewage

spill during operation of the

WWTP causing soil

contamination / seepage to

groundwater

Terrestrial ecosystems /

Groundwater / Millstream

Public Drinking Water Source

Area Priority Zone 2 / Surface

Water (>800m away)

Soil / groundwater

contamination.

Impacts to native vegetation

from inundation

The WWTP will be appropriately designed (skid

mounted) and operated to mitigate the risk of

sewage spills.

Surface water management structures / bunding will

ensure any spills are contained.

The entire facility is bunded to capture overflow or

rain event freeboard and prevent discharge without

treatment

Spill response will be provided.

Inspection and maintenance will be undertaken.

Moderate Unlikely Medium Detailed assessment provided in

Section 6.7


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Source Potential

Emissions Pathway Potential Receptors Potential Impacts Proposed Controls Consequence Likelihood Risk Rating

Detailed Assessment

Required?

Treated

effluent

Discharge to land (sprayfield)

/ seepage to groundwater




Area Priority Zone 2

Elevated nutrient levels in soil

/ groundwater potentially

causing euthrophication

Impacts to native vegetation /

ingress or spread of weeds.

Irrigation sprayfield sized appropriately as per

contaminant loading guidelines within the Water

Quality Protection Note 22 “Irrigation with nutrient-

rich wastewater”.

Comprehensive effluent water quality monitoring

schedule

Moderate Possible Medium Detailed assessment provided in

Section 6.7

Non-prescribed

activities

Hydrocarbons

(under criteria

for licensing)

or other

chemicals

used in

construction or

operation of

the WWTP and

Camp

Hydrocarbons /

Other

chemicals

Hydrocarbon spill from

storage or refuelling activities

resulting in soil contamination

/ seepage to groundwater

Vehicle wash-down activities




Area Priority Zone 2 / Surface

Water (>800m away)

Soil / groundwater

contamination leading to

decline in water quality

Conformance with procedures for bringing chemicals

to site including ensuring a Safety Data Sheet (SDS)

being available and accessible for each chemical

All storage containers and areas will be

appropriately labelled, as required by relevant

legislation and Australian Standards

All hazardous materials storage facilities and

generators will be bunded

Emergency response spill kits will be co-located at

all storage locations

Daily site inspections will be conducted of hazardous

materials use and storage

Refuelling transfer points will be secondarily

contained

Refuelling will not occur within 30m of a watercourse

Mobile refuelling trucks must carry spill kits

Wash down facility designed with bunding and

sumps to contain potentially contaminated waters

All refuelling and servicing shall be done at

designated locations on site, with drip trays and spill

kits (including absorbent matting) available to

contain potential spills and drips.

Moderate Possible Medium Detailed assessment provided

provided in Section 6.8

General

wastes

generated in

construction

and operation

of the WWTP

and Camp

Solid / Liquid

Waste

None. Any general wastes

generated during

construction will be removed

from site by a licensed

contractor.

Terrestrial ecosystems Soil / groundwater

contamination.

Windblown litter (amenity).

Increase in feral animals.

General wastes will be managed via standard

operating procedures including:

- sufficient recycling and general waste collection

areas will be established and labelled with the

relevant waste type to facilitate the management

of waste;

- recyclable materials will be separated from other

waste and recycled wherever possible; and

- non-recyclable materials will be transported to,

and disposed of, at an approved off-site facility by

a licensed contractor.






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6 Emission Management

RTIO (WA) has a Health, Safety, Environment and Quality Management System (HSEQMS) that ensures environmental controls are developed for key environmental aspects, legal compliance is maintained and continuous improvement is achieved through a formal review process. A Construction Environmental Management Plan (CEMP) is also in place which details the environmental management commitments necessary to mitigate the environmental impacts associated with the construction activities. Environmental aspects of the WWTP construction and operation will be managed in accordance with the CEMP, the Rio Tinto Environmental Design Principles for Temporary Facilities (DC-N002) and with all relevant conditions of Ministerial Statement 999.

6.1 Air Emissions (not including dust)

There will be no major air emissions, with the exception of dust (refer Section 6.2) generated during the construction and operation of the Camp, WWTP and associated sprayfield. During construction the generation of smoke and gaseous emissions will be limited to the operation of construction machinery including earthmoving machinery and temporary power generation. Normal operation of the WWTP will not result in the generation of additional air emissions, hence the environmental risk is negligible

6.2 Dust Emissions

Dust emissions during construction are typically associated with clearing, earthworks and vehicle movement on unsealed roads. Dust emissions during construction will be managed in accordance with the CEMP. Minor earthwork activities during the installation of the WWTP have the potential to generate small amounts of dust. The dispersed and temporary nature of dust emissions during construction requires a broad range of controls to be applied including:

Reducing ground disturbance to only the areas require for construction activities;

Water carts will be used during construction activities and in areas with frequent vehicle

movement on unsealed roads. The application of water increases the specific mass of

the soil particles and to increase bonding between the soil particles, minimising the

dust generated;

In some transport corridors, dust suppressant additives may be applied through water

carts to assist with dust control;

Site clearing and rehabilitation will be managed to ensure that areas are only cleared

as required and progressive rehabilitation is implemented as construction activities are

completed; and

Weather forecasts will be monitored to ensure the availability of adequate water carts

if there is a risk of windy conditions.


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Implementation of the CEMP requires regular documented inspections to be undertaken to ensure the dust management techniques are being applied appropriately during construction and operation. Normal operation of the WWTP will not result in the generation of additional dust emissions, and given the lack of any sensitive receptor, the environmental risk from dust emissions is low.

6.3 Noise Emissions

Noise emissions during construction will be distributed across the site, predominantly mobile and limited to daylight hours. The main source of noise emissions will be earthmoving and construction machinery and on-site power generation. Noise and vibration are not expected to be significant for either construction or operation of the proposed facility. Minor earthworks during construction will result in the short term increase in local noise levels. During the construction period there will be no nearby sensitive noise receptors. Construction noise emissions will be managed under the CEMP. Controls include:

fitting vehicles and stationary items of equipment with exhaust mufflers;

screening or enclosing stationary items of equipment with acoustic enclosures to reduce operating noise levels;

the requirement for contractors to comply with the Environmental Protection (Noise) Regulations 1997; and

construction works must be carried out in accordance with Section 6 of Australian Standard 2436-1981 “Guide to Noise control on Construction, Maintenance and Demolition Sites” and the Environmental Protection (Noise) Regulations 1997 (WA).

Once operational, the WWTP will operate on a continuous 24 hours per day basis, however normal operation of the WWTP will not result in the generation of additional noise emissions. The environmental risk to any sensitive receptor from this emission is low.

6.4 Odour Emissions

During construction and installation of the WWTP there will be no additional odour emissions from the works area. Under normal operating conditions there are no significant odour emissions from the WWTP, hence there is no risk associated with this emission.

6.5 Light Emissions

Light emissions during construction of the WWTP are expected to be minimal. Construction activities will not be conducted at night and so night lighting will be limited to the minimum required to maintain site safety and security. Directional lighting will be used to minimise stray light emission. When constructed and commissioned the WWTP will operate on a continuous 24 hour basis, and additional lighting may be installed at the facility for the safe running and maintenance of the facility during night time operations. This lighting shall be limited to the minimum required for safe operations in accordance with Australian standards.


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Plant lighting design will comply with Australian standards for safe work.

The environmental risk to any sensitive receptor from this emission is low.

6.6 Discharge to Water

There are no planned or permitted discharges to water during construction, installation or operation of the WWTP. Weelumurra Creek, the closest non-perennial water source is greater than 800m from the proposed WWTP hence there is no risk to surface water receptors.

6.7 Discharges to Land

6.7.1 Millstream Water Reserve Public Drinking Water Source Area

The WWTP will be located within the Millstream Water Reserve Public Drinking Water Source Area, in an Outer Catchment Priority Zone 2, which presents a potential risk of untreated discharges of waste water to the terrestrial environment through impacted pipes, overflow of containers or blocked components at the WWTP. The WWTP is skid mounted and will be constructed within an earthen bunded area to prevent the ingress of surface water and contain any spills within the immediate footprint. Pipelines used to deliver waste water to the WWTP from the proposed Pelican Camp will be designed and constructed to meet the requirements of Water Services Licensing (Plumbers Licensing and Plumbing Standards) Regulations 2000 and be protected from impact, flooding and fire. Under normal operations, a failure of the WWTP is not expected to result in waste water being discharged due to design standard requirements and contingency planning.

6.7.2 Identification and general characterisation of emissions

The maximum hydraulic application rate is equivalent to 3.5 mm/m2/day over the entire 2.1 ha irrigation field. Effluent nutrient loading calculations have been based on operating at 100% of peak manning of 200 persons, irrigating the total capacity (74kL) to the 2.1 ha spray field 365 days/year. Though not directly applicable to sewage discharge, the principles of the Department of Water and Environmental Regulation, Water Quality Protection Note 22 “Irrigation with nutrient-rich wastewater” (DOW, 2008) have been applied to this project. In accordance with WQPN 22 table 1 – Eutrophication risk based on soil type and location the acceptable range of nutrient application for risk Category B soils is 180 kg Nitrogen/ha/year and 20 kg Phosphorus/ha/year.


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The expected annual nutrient loading based on the information in Table 6-3 and a sprayfield area of 2.1 ha will be:

TN – (13 mg/L/1,000) = 0.000013kg/L x 74,000 L/day (design output) = 0.962kg/day x 365 (operating days / year) = 351.15kg/year / 2.1 ha = 167.20 kg/ha/year

TP – (1.5 mg/L / 1,000) = 0.0000015kg/L x 74m3/day (design output) = 0.111kg/day x 365 (operating days / year) = 40.51kg/year / 2.1ha = 19.29 kg/ha/year

Based on these calculations, the discharges to land remains below the DWER recommended maximum application limit for Eutrophication Risk Category B soils shown in Table 6-1.

Table 6-1: Department of Water, Water Quality Protection Note 22- nutrient loading rates

Parameter WWTP WQPN 22 Target

Total nitrogen (kg/ha/year) 167.20 180

Total Phosphorus (kg/ha/year) 19.29 20

To ensure ‘low contact’ reclaimed water use is maintained with the thermo-tolerant coliform

discharge criteria <1,000cfu/100ml as per the Guidelines for Sewage Systems – Use of

Reclaimed water (ARMCANZ, NHMRC & ANZECC, 2000), restricted access during irrigation

is required. This is achieved through the fencing of the irrigation area and signage advising

that the areas will be irrigated with recycled water.

Drainage control will not be required due to equipment selection and physical design of the irrigation spray field. The low drift fan-spray nozzles proposed provide a coarse droplet with an even spray radius and distribution, designed to prevent pooling through pressure and flow specifications. The spray field irrigation layout allows for planned maintenance of the spray field at any time of the day, where the relief of the spray irrigation area is mildly graded, leading to very good infiltration of effluent.

6.7.3 Design Criteria

Criteria for the construction and operation of WWTPs is provided in the following key policies and guidance documents:

Koodaideri Project Construction Environmental Management Plan (KD-9900-H-PLN-00001)

Rio Tinto Environmental Design Principles for Temporary Facilities (DC-N002)

Rio Tinto WWTP Standard Specification (SS-N104)

Activities within the Millstream P2 PDWSA zone will align, where practicable, with the DWER Water Quality Protection series, and only to the extent the WQPN is relevant and appropriately applied using a common sense approach to works and/or activities.


29

Water quality protection management practices that have (ranging) relevance to the proposed Pelican Camp and WWTP construction and operation include, but are not limited to:

WQPN 22: Irrigation with nutrient rich waste water1

WQPN 41: Private drinking water supplies

WQPN 61: Tanks for ground level chemical storage

WQPN 65: Toxic and hazardous substance storage and use

WQPN 68: Mechanical equipment washdown

WQPN 70: Wastewater treatment – onsite domestic systems

6.7.4 Inputs and Outputs

The WWTP will be used solely for treating raw sewage. No trade or other wastes will be input to the system. Table 6-2 provides the expected loading rates for raw sewage in the WWTP.

Table 6-2 Expected raw sewage loading rates

The treated effluent is designed to exceed the National Water Quality Management Strategy (NWQMS: Australian Guidelines for Sewage systems – Effluent Management, 1997) discharge criteria as shown in Table 6-3 (maximum daily discharge of 74kL/day of treated effluent).

1 Though not directly applicable to sewage discharge, the principles of the WQP Note 22 have been applied to this project.

Inputs Loading Rate

5 day Biological Oxygen Demand 300 mg/L

Total Suspended Solids 300 mg/L

Total Nitrogen 80 mg/L

Total Phosphorus 15 mg/L

pH 6.5 – 8.5


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Table 6-3 NWQMS, Water Quality Discharge Criteria

6.7.5 Proposed environmental controls

The controls proposed to manage any potential adverse impact from WWTP emissions are listed in Table 6-4.

Table 6-4 Proposed environmental controls

Objective Site Controls

No overflows of waste water

material from the WWTP

WWTP bund with sufficient freeboard maintained.

High level audible and visual alarms.

No ingress of clean surface

water

Diversion of clean surface water around the WWTP

area.

No hazardous materials

contamination

Secondary containment of all chemical and hydrocarbon

storage across the site.

All storage tanks and transfer piping will be above

ground.

Internal assessment and approval process prior to

mobilising any chemicals to site.

Documented daily inspections of storage and transfer

areas.

Contain spillage caused by

rupture, leak, overflow or

rainfall event

The entire facility is bunded to capture overflow or rain

event freeboard and prevent discharge without treatment

Physical separation from Camp

potable water source

The Proposed Pelican Camp potable water supply

groundwater bore, WB18KRP0014, is located up-

gradient approximately 500m away.

Given the proposed environmental controls, the residual risk to soil contamination and groundwater (and hence the P2 PDWSA zone) from operation of the waste water treatment plant is seen as low.

Outputs WWTP Target Value NQWMS Discharge

Criteria

5 day Biological Oxygen Demand <20 mg/L 20 – 30mg/L

Total Suspended Solids < 5 mg/L 25 – 40mg/L

Total Nitrogen <13 mg/L 20 – 50 mg/L

Total Phosphorus <1.5 mg/L 6 – 12 mg/L

pH 6.5 – 8.5

Residual free chlorine 0.2 – 0.5 mg/L

Thermo-tolerant Faecal Coliforms < 500 cfu/100mL <10,000 cfu/100mL


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6.8 Hydrocarbon and Chemical Storage

6.8.1 Identification and general characterisation of emissions

All fuel storage and chemical storage facilities for the Camp will be designed in accordance with the Dangerous Goods (Storage and Handling of non–explosive) Safety Regulations 2007, Australian Standard 1940:2004 The Storage and Handling of Flammable and Combustible Liquids and the Rio Tinto Environmental Design Principles for Temporary Facilities (DC-N002).

Hydrocarbon storage within the P2 PDWSA zone will align, where practicable, with the DWER Water Quality Protection series, and only to the extent the WQPN is relevant and appropriately applied using a common sense approach to works and/or activities. Water quality protection management practices that have (ranging) relevance to the proposed hydrocarbon storage, but are not limited to:

WQPN 61: Tanks for ground level chemical storage

WQPN 65: Toxic and hazardous substance storage and use

The diesel storage and refuelling facility, will include high-flow and low-flow refuelling bowser and fuel management system and will have a direct above ground connection to the Camp diesel power generation facility. An oily water separator will be installed to cater for the diesel storage and refuelling facility, and include drying and holding facilities. A light-vehicle wash down facility will also be located within the vicinity of the diesel storage and refuelling facility. The wash down facility will be appropriately designed (e.g. bunding and sumps installed as well as appropriately lined) and maintained so as to ensure any contaminated waters are captured and removed for appropriate treatment. The facility will comply with the requirements of the DWER Water Quality Protection note 68: Mechanical equipment washdown.

6.8.2 Proposed environmental controls

The controls proposed to manage any potential adverse impact from the storage or use of hydrocarbons or other chemicals are listed in Table 6-5.


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Table 6-5 Proposed environmental controls

Objective Site Controls

No hazardous

materials

contamination of soils,

groundwater or

waterways from

storage or use of

hydrocarbons or other

chemicals

Conformance with procedures for bringing chemicals to site including ensuring a Safety Data Sheet (SDS) being available and accessible for each chemical

A list of hydrocarbons, chemicals and hazardous materials must be presented to the Company (or Representative) for approval before mobilisation

All storage containers and areas will be appropriately labelled, as required by relevant legislation and Australian Standards

All hazardous materials storage facilities and generators will be bunded

All activities related to the transport, handling, storage and use of hazardous materials will be conducted in appropriate ways, and as per relevant legislation, so as to prevent negative impacts to the environment

All spills regardless of size must be reported to the Company (or Representative)

Emergency response spill kits will be co-located at all storage locations

Daily site inspections will be conducted of hazardous materials use and storage

Refuelling transfer points will be secondarily contained

Refuelling will not occur within 30m of a watercourse

Mobile refuelling trucks must carry spill kits

Wash down facility designed with bunding and sumps to contain potentially contaminated waters

All refuelling and servicing shall be done at designated locations on site, with drip trays and spill kits (including absorbent matting) available to contain potential spills and drips

Given the proposed environmental controls, the residual risk to soil contamination and groundwater (and hence the P2 PDWSA zone) from hydrocarbons (and other chemicals) is seen as low.


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6.9 Solid/Liquid Waste

There are no liquid waste by-products generated by the proposed WWTP during construction. During normal operations, the inlet screen collects any solid waste transferred through the conveyance system prior to entering the flow balance tank. This system automatically dewaters solids and collects them to be removed offsite to a licenced landfill site. Sludge will be transported off-site by an appropriately licensed Contractor. Solid industrial and domestic waste will be generated during the construction and operation of the WWTP. Waste material that is suitable for re-use or recycling will be separated from landfill waste and sent off-site for treatment or recycling as practicable. Non-recyclables will be transported off-site by an appropriately licensed Contractor. All Controlled Waste including hydrocarbon contaminated water will be removed from site via an appropriately licensed controlled waste carrier and relevant records including tracking notes maintained on site for audit and inspection purposes. All waste handling procedures will be in accordance with the CEMP during construction and the RTIO Health Safety Environment and Quality (HSEQ) Management System during operations. There are no other discharges to land associated with this proposal.

6.10 Flora and Fauna

New clearing is required for the construction of the WWTP, associated infrastructure and

temporary access. It is expected that up to 13 ha of clearing is required for the entire Camp

footprint. This area has been the subject of detailed flora and fauna surveys. Approximately

0.4 ha will be required for the footprint of the WWTP itself. The construction and operation of

the WWTP will not affect any Conservation Significant Flora and Fauna or Matters of National

Environmental Significance.

The Rio Tinto Approval Request and Ground Disturbance permitting process will be used to

directly control all land clearing and ground disturbing activities on site. Issuing permits

involves extensive analysis using GIS data acquired through professional botanical and

ecological surveys. The commencement of work under approved permits requires formal

survey, delineation of clearing limits, direct supervision of land clearing activities, mandatory

land disturbance training and extensive reporting including survey pick and assessment via

GIS applications.


34

7 Monitoring

Representative WWTP influent and effluent samples will be collected and analysed in accordance with Table 7-1. All water samples will be collected, handled and preserved in accordance with Australian Standard 5667 and have analyses conducted by an laboratory with current NATA accreditation for the specified parameters.

Table 7-1 WWTP water quality monitoring requirements

Monitoring

Location

Parameter Phase Frequency

Effluent Residual free chlorine Commissioning Daily

Influent &

Effluent

Flow volume

Pelican Camp occupation

Commissioning Weekly

Effluent 5 Day Biological Oxygen Demand

Total Suspended Solids

Total Nitrogen

Total Phosphorus

pH

Thermo-tolerant Faecal Coliforms

Commissioning Monthly

Effluent pH

Residual free chlorine

Operation Daily

Effluent Flow volume

Pelican Camp occupation

Sludge Removal

Operation Monthly

Effluent 5 Day Biological Oxygen Demand

Total Suspended Solids

Total Nitrogen

Total Phosphorus

pH

Thermo-tolerant Faecal Coliforms

Operation Quarterly

General Daily inspection for general leaks and spills Commissioning

and operation

Daily


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8 Rehabilitation and Closure

After construction works are completed, areas that have been cleared and no longer required for operational use will be rehabilitated. All building materials, structures and facilities will be dismantled and removed from the site. The sewage treatment plant will be drained of sewage and sludge which will be disposed of in an approved waste disposal facility off-site. Rehabilitation will include:

the removal of all concrete footings, surface level tie-downs, paths, slabs etc and their reuse within the Company or burial at an approved and appropriately licensed location;

disconnection and/or removal of services below ground level;

filling of excavations and holes,

spreading of previously stockpiled topsoil; and

contour ripping of the site. The closure of the WWTP facility will be incorporated into the overall closure planning for the site and will follow the Pelican Camp Closure Plan regulated by the Department of Mines, Industry Regulation and Safety under the Mining Act 1978.

9 Project Costs

Costs associated with the deployment and installation of the WWTP and sprayfield are detailed below:

Table 9-1: Project Costs

Project Description Projected Cost

$ AUD

Cost of works

Supply and install 146,161

Rental cost 120,900

Preliminary costs 16,100

TOTAL COST $ 283,161


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10 Summary of Commitments

Environmental factor

Potential impacts Proposed management Section number

Commitment

Dust Emissions Dust generated from clearing and vehicle traffic on unsealed access tracks.

Unsealed work areas and access tracks will be regularly sprayed

with water during construction

Water to be used as dust suppression during construction and

Operation (where required)

6.2

Clearing restricted to areas

required for construction related

activities.

Application of dust suppression water where necessary.

Odour Emissions Unpleasant odours from WWTP operation

WWTP will be located to minimise the potential for odour impacts on Pelican Camp residents during normal operation 6.4

No complaints received in relation to odour from the WWTP

Light Emissions Light spill from operations

Additional lighting may be installed at the facility for the safe running and maintenance of the facility during night time operations. This lighting will be limited to the minimum required for safe operations.

6.5 Lighting will be limited to the minimum directional lighting required for safe operations

Discharges to Water

Impact to groundwater water quality outside of natural variation

There will be no discharges to water as a result of the WWTP construction, installation and operation.

6.6 No discharges to water from the construction, installation and operation of the WWTP

Discharge to Land

Nutrient enrichment of waterways/ groundwater from excess nutrient loading in irrigation wastewater

WWTP system to be designed and commissioned to meet

discharge performance criteria

Monitoring of waste water treatment plant effluent quality from commissioning phase through to Operations and beyond

An earthen bund will be established around the perimeter of the

spray field to further prevent runoff into the surrounding

environment

Irrigation field fenced and within area proposed, with sprinklers placed to prevent spray overlap.

6.7; 7

Loading rate at end of commissioning below relevant criteria (Table 6-3) Commence monitoring in proposed commissioning period in order to assess any early warning signs regarding water quality impacts

Irrigation field fenced, earthen bunded and within area proposed, with sprinklers placed to prevent spray overlap


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Commitment

Unauthorised Discharge

Nutrient enrichment of waterways/ groundwater from excess nutrient loading in irrigation wastewater

System designed with adequate controls to prevent overflow to open ground

Hazardous materials to be stored in appropriately designed area

6.7

Tank high level alarms installed Process electrical interlocks installed Entire facility is fully bunded.

Hazardous materials stored in appropriately designed facility

Hydrocarbon / Chemical Storage

Potential for soil or water contamination from hydrocarbon or chemical spills.

All small quantities of hydrocarbons and/or chemicals to be stored in secondarily contained areas.

All chemicals associated with the proposed WWTP, such as chlorine and alum will be stored in a secure, appropriately designed storage area. The unit includes lockable gates, signage and spill containment tray. The unit will be ventilated and includes a safety shower, eyewash and green safety light.

Waste oil, oily rags, oil filters, and any other hydrocarbon related wastes shall be collected and disposed through an appropriately licensed waste service provider.

Spill kit equipment will be located near all higher risk contamination points. All site vehicles and machinery will also carry spill kits.

6.8

Hydrocarbon and chemical storage areas, and refuelling areas constructed with secondary containment measures

Spill kit equipment will be located near all higher risk contamination points.

Solid/ Liquid Waste

Solid industrial and domestic waste generated during the construction and operation of the proposed Pelican Camp

Principles of reduce, reuse and recycle to be adopted during construction period and operations. 6.9

All solid waste that cannot be recycled will be disposed at offsite landfill.


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Commitment

Discharge of untreated waste water to the environment

Waste water pump stations, macerator pits, sewage pipeline, treatment plant (including freeboard) and sprayfield to be inspected regularly.

A recovery system will be utilised if required to manage excess waste water within the WWTP facility.

6.9

Monitoring of infrastructure regularly during operation to ensure there is no failure resulting in a spill to the environment

The construction, installation and operation of the proposed Pelican Camp WWTP will not trigger or cause contamination within the area


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Appendix A Drawings


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Appendix B Photographs – Typical Plant Layouts


45

Typical arrangement of Membrane Reactor Waste Water Trreatment Plant within a lined bunded containment area.


46

Typical arrangement of a self contained double skinned fuel storage and dispensing tank. Above ground, self contained drive over spill

containment grates are shown in the foreground.


Koodaideri Project - der.wa.gov.au

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