Balmoral South Iron Ore Project PER - Task 1 A

Appendix F

Marine Impact Assessment

Water Production Desalination Plant

at Cape Preston

Draft Memorandum

C:\DOCUM E~1\CHRIS_~ 1\LOC ALS~1\Temp\notesE1EF 34\Bal moral South Iron Or e Proj ect PER - T ask 1 a. Revised M emo to IM 12 D ec 08 DRAFT .doc Date: 12 December 2008

To: Josephine Wang - International Minerals

From: Chris Coffey - URS

Subject: Balmoral South Iron Ore Project PER - Task 1 a.

Dear Josephine,

This revised memo has been prepared to address Task 1.a of URS’ proposal dated 5 December 2008, and the subsequent International Mineral’s Authority to Commence Works dated 9 December 2008. It follows my previous memo, and has been revised in the context of providing information to be included in IM’s response table to the EPA regarding issues raised in the original PER.

TASK

Task 1.a requires URS to provide further empirical or scientific justification to the following statement within the PER (p 7-33): “it is considered most unlikely that the construction and operation of the outfall will seriously disrupt the lifecycle of an ecologically significant proportion of the population of either dugongs or turtles”.

Additional Information

The Cape Preston area has not been identified to support an ecologically significant proportion of the population of either dugongs or turtles within the Pilbara region. Furthermore, given the fact that disturbances from operation and construction will be localised, it is very unlikely they will have any significant impact on dugongs and turtles that do use the area. This is based on the following information:

 Population studies of Dugongs in the Pilbara region undertaken in the 1980’s identified that the greatest dugong concentrations occurred in areas between Middle and North Mangrove Islands, Regnard Bay, Nickol Bay and the Dampier Archipelago. Follow up surveys in April 2000 estimated population numbers to be 2046 (±s.e. 376) dugongs, at an average density of 0.10 dugongs per km². This study also confirmed that the greatest populations occurred in those areas reported in the 1980’s study (Marsh, et.al 2002).

 Benthic Habitat mapping undertaken by URS has confirmed that the Cape Preston area does not contain habitat considered significant for dugongs, which includes large expanses of shallow water with dense seagrass meadows.

 A report by Pendoley Environmental to URS stated that snap shot surveys undertaken over three separate turtle nesting seasons (2000/01 02/03, 04/05) identified that during these seasons very limited nesting was taking place on Cape Preston. These results showed that nesting effort was clearly less intense than other areas surveyed, including Cowrie Beach and Mundabullangana Station.

 Pendoley Environmental also reported that although green turtles have been observed to use the near-shore algal-rock benthic community as feeding habitat, no mating activity has been observed.

URS Australia Pty Ltd (ABN 46 000 691 690) Level 3, 20 Terrace Road East Perth WA 6004 Australia Tel: 61 8 9326 0100 Fax: 61 8 9326 0296

 Marsh et.al. 2002 stated that although individual dugongs and turtles may be impacted by industrial construction and operational disturbances, population level effects are unlikely.

 The environmental effects of brine discharge on dugongs, turtles or other large marine fauna have not been studied at other desalinisation plants. However, there is no information available that suggests brine discharge will have a negative effect on dugong or turtle health. Furthermore, there are many examples of dugongs and turtles living in sea areas with elevated salinities.

 Dugongs and marine turtles are large, highly mobile animals in relation to the size of the brine mixing zone proposed. Because of their mobility, it is expected that exposure to environmental conditions within the mixing zone, even if they were to be adverse, will be minimal.

REFERENCES

Marsh, H., H. Penrose, C. Eros, and J. Hugues. 2002. Dugong: Status reports and action plan for countries and territories. UNEP Early Warning and Assessment Report Series.

North Australian Indigenous Land and Sea Management Alliance. 2006. Dugong and Marine Turtle Knowledge Handbook. Indigenous and scientific knowledge of dugongs and marine turtles in northern Australia. February 2006.

Pendoley, K. (2005). Sea Turtles and Industrial Activity on the North West Shelf, Western Australia. School of Biology and Biotechnology. Perth, Murdoch University.

Pendoley Environmental Pty Ltd (2006). Review of Sea Turtle Habitat Usage Reports – Cape Preston Area 2000 to 2005. Prepared for URS Australia. March 2006.

Prince R.I.T. 2001. Aerial Survey of the Distribution and Abundance of Dugongs and Associated Macroinvertebrates Fauna - Pilbara Coastal and Offshore Region, WA, Completion Report. Prepared by: Marine Species Protection Program, Department of Conservation & Land Management, WA. Prepared for: Environment Australia. May 2001.

Prince, R.I.T., P.K. Anderson, and D. Blackman. 1981. The status and distribution of dugongs in Western Australia. In: Marsh, H. (ed.). The Dugong: Proceedings of a Seminar/Workshop held at James Cook University 8-13 May 1979. James Cook University of North Queensland, Townsville, Australia. pp. 67-87.

Yours faithfully,

URS AUSTRALIA PTY LTD

Chris Coffey

Project Environmental Scientist

4J:\Jobs\43177570\6 Deliv\Balmoral South PER input\Desalination Section\43177570 R1337 Marine PER Water Production Desal Plant Final 10 Sep 08.doc Marine Impact Assessment Water Production Desalination Plant at Cape Preston

REPORT Marine Impact Assessment Water Production Desalination Plant at Cape Preston

Prepared for

International Minerals Pty Ltd

Level 4, 5 Mill Street Perth WA 6850

10 September 2008 43177570-1892 : R1337

MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Project Manager: Anthony Bougher Associate Environmental Scientist URS Australia Pty Ltd Level 3, 20 Terrace Road East Perth WA 6004 Project Director: Ian LeProvost Australia Senior Principal Tel: 61 8 9326 0100 Fax: 61 8 9326 0296

Authors: Chris Coffey Date: 10 September 2008 Petra Ringeltaube Reference: 43177570-1892 : R1337 Blair Hardman Status: Final Report

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Table of Contents

Table of Contents 1 Introduction ...... 1 2 Existing Marine Environment ...... 3 2.1 Bathymetry ...... 3 2.2 Climate ...... 5 2.3 Tidal Water Levels...... 7 2.4 Currents ...... 8 2.5 Wave Climate...... 8 2.6 Coastal Processes ...... 10 2.7 Water Quality ...... 12 2.7.1 Temperature, salinity, pH and oxygen...... 12 2.7.2 Turbidity and total suspended solids ...... 14 2.7.3 Nutrients and trace elements...... 14 2.7.4 Sediment quality ...... 14 2.8 Distribution of marine biota and benthic habitats...... 15 2.8.1 Macroscale biogeography ...... 15 2.8.2 Mesoscale regionalisation ...... 15 2.8.3 Marine flora...... 16 2.8.4 Sessile marine biota ...... 16 2.8.5 Benthic habitats ...... 17 2.9 Marine Fauna ...... 20 2.9.1 Marine turtles ...... 20 2.9.2 Dugongs ...... 20 2.9.3 Other fauna...... 21 2.10 Social values and uses...... 21 3 Relevant Environmental Factors...... 23 3.1 EPA Guidance Statement No. 29: Benthic Primary Producer Habitat Protection for WA’s marine environment...... 23 3.2 The Proposed Regnard Marine Management Area...... 24 3.3 Pilbara Coastal Waters – Environmental Values and Environmental Quality Objectives ...... 25

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Table of Contents

4 Potential Impacts and their Mitigation...... 28 4.1 Construction of Brine Outfall Pipeline...... 28 4.1.1 Objectives and standards ...... 28 4.1.2 Construction details ...... 28 4.1.3 Potential impacts ...... 28 4.1.4 Management and mitigation ...... 29 4.1.5 Alternative outfall pipeline route...... 30 4.2 Construction of the Seawater Intake...... 31 4.2.1 Objectives and standards ...... 31 4.2.2 Potential impacts ...... 31 4.2.3 Management and mitigation ...... 31 4.2.4 Alternative intake location...... 31 4.3 Operation of the Brine Discharge...... 31 4.3.1 Objectives and standards ...... 31 4.3.2 Description of brine discharge ...... 32 4.3.3 Potential impacts of brine discharge...... 32 4.3.4 Outfall site selection...... 32 4.3.5 Brine dilution ...... 33 4.3.6 Brine modelling ...... 33 4.3.7 Modelling results...... 33 4.4 Brine Composition and Potential Effects ...... 35 4.4.1 Desalination process and composition of brine effluent ...... 35 4.4.2 Impact assessment...... 37 4.4.3 Overall effects on the ecosystem...... 42 4.5 Seawater Return Outfall ...... 44 4.5.1 Objectives and standards ...... 44 4.5.2 Potential impacts and their mitigation...... 45 4.5.3 Interactions and cumulative impacts of brine discharges...... 45 4.6 Effect of Brine Outfall Construction and Operation on EPBC Listed Species ...... 45 4.6.1 Other marine species...... 49

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Table of Contents

5 Water Quality Management Framework ...... 51 5.1 Water Quality Management Framework...... 51 5.1.1 Environmental values and quality objectives...... 51 5.1.2 Application of EVs, EQOs and EQC to the Cape Preston area ...... 51 5.2 Monitoring and Reporting ...... 55 5.2.1 Diffuser performance monitoring ...... 55 5.2.2 Wastewater stream monitoring...... 55 6 Performance Indicators ...... 57 7 References...... 59 8 Limitations of Report ...... 63

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Tables, Figures, Plates, Appendices

Tables, Figures, Plates, Appendices Tables

Table 2-1 Tidal planes at Cape Preston compared with those at Dampier...... 8 Table 2-2 Mean water quality characteristics – 2007...... 12 Table 2-3 Physical characteristics of the water column in the vicinity of the brine outfall – May 2008...... 13 Table 2-4 Dissolved metal concentrations in water in the vicinity of the brine outfall site ...... 13 Table 3-1 Cumulative loss thresholds for BPPH within defined management units for six categories of marine ecosystem protection ...... 23 Table 3-2 Levels of Ecological Protection for the Maintenance of Ecosystem Integrity ...... 26 Table 4-1 Chemicals used in the RO process and dilutions in the marine environment...... 37 Table 4-2 Possible source of operational impacts of RO plants and applicability to the proposed Balmoral South Project plant...... 38 Table 4-3 Coastal sub-ecosystems and characteristics ranked according to their sensitivity (based on Höpner & Windelberg 1996, in Münk 2008)...... 44 Table 5-1 Interim EVs, EQOs and EQC for Cape Preston Waters ...... 53 Table 6-1 Proposed performance indicators for desalination outfall management...... 57

Figures

Figure 2-1 Cape Preston Bathymetry ...... 4 Figure 2-2 Cape Preston Monthly Wind Roses ...... 6 Figure 2-3 Cyclone Tracks in the Vicinity of Cape Preston 1950-2008...... 7 Figure 2-4 Hindcast wave conditions at nearshore Cape Preston February 2001-2005 ...... 9 Figure 2-5 Hindcast wave conditions nearshore Cape Preston July 2001-2005 ...... 10 Figure 2-6 Cape Preston geomorphic components...... 11 Figure 2-7 Cape Preston Benthic Habitats ...... 18 Figure 2-8 Designated marine social uses in the vicinity of Cape Preston ...... 22 Figure 3-1 Proposed Regnard Marine management Area ...... 25 Figure 3-2 Environmental Values and Objectives for Cape Preston Waters ...... 27 Figure 4-1 Percentage compliance of the two proposed brine discharges ...... 34 Figure 4-2 Example of macro-tidal range over neap tides (11 to 17 May 2008) and spring tides (18 to 24 May 2008) ...... 43 Figure 5-1 Proposed ecological protection areas for the proposal area ...... 54 Figure 5-2 Conceptual diagram providing guidance for maintenance of environmental quality (EPA, 2005). 56

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Tables, Figures, Plates, Appendices

Plates

Plate 2-1 LAT Aerial Survey October 2007 – the large Goniastera and Lobophyllia reef which is located along the south-eastern shore of SW Regnard Island. The southern part of the reef exhibits up to 100% live coral cover, whilst the northern part has up to 40% live coral cover...... 19 Plate 2-2 LAT Aerial Survey October 2007 – close-up of high cover coral community north of Preston Spit19 Plate 4-1 Seafloor in the vicinity of the brine outlet location...... 29

Appendices

A Cape Preston Preliminary Water Quality Investigations B Dugong Literature Review - Onslow to Dampier, WA C Cape Preston Desalination Plant Brine Discharge Modelling Study D Material Data Safety Sheets - PermaCare International and Nalco

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Introduction Section 1

1 Introduction

This report analyses the dispersion of the brine outfall from a proposed desalination plant at Cape Preston for the Balmoral South Project and the potential environmental impacts of such an outfall.

The report also assesses the environmental effects of constructing and operating a seawater intake, and a seawater return outfall for the desalination plant, assuming that a port will already be in place at Cape Preston and that the intake and outfalls will be able to hang off existing facilities.

The report will also:

• Describe the key characteristics of the marine environment in the area,

• Describe the proposed construction activities required for the various outfalls, seawater intake and via hydrodynamic modelling,

• Determine the scale of mixing zone required to achieve the number of dilutions necessary to meet the water quality criteria established for the Austeel project at Cape Preston by Ministerial Statement 635 (October 2003).

• Present an assessment based on literature review of the impacts of the brine effluent discharge and the level of risk it poses to the marine environment off Cape Preston. An outline of the environmental management and monitoring framework is presented in this section, whilst a detailed Wastewater Outfall Management Plan is presented in the Project Operations EMP.

The proposed Balmoral South Project Desalination plant has discharges of:

• Produce 109 000 m3/day of fresh water • Produce 157 000 m3/day of brine • 78.8 ppt salinity (approximately) • TDS approximately twice that of incoming seawater

This Central Block desalination plant (which has already been approved) has discharges of:

• Produce 120 000 m3/day of fresh water production • Produce 175 000 m3/day of brine • 78.8 ppt salinity (approximately) • TDS approximately twice that of incoming seawater

The modelled Balmoral South Project Desalination Plant has discharges of:

• Produce 175 000 m3/day of fresh water • Produce 252 000 m3/day of brine • 78.8 ppt salinity (approximately) • TDS approximately twice that of incoming seawater

This discharge (157 000 m3/day) of the proposed Balmoral Project Desalination plant is well below the modelled discharges of 252 000 m3 /day and is also slightly below the discharge for the Central Block Project (175 000 m3/day).

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Section 1 Introduction

The modelling shows that the mixing zone areas from diffusers 150 m long are:

Mixing zone % Central Block Balmoral South of time to Proposed Outfall Project Outfall achieve 40 x (ha) (ha) dilution 99% 3.9 3.5 95% 1.5 1.2

The modelling can be interpreted to show that any location in the vicinity of the 8 m water depth would give similar dispersion.

It is considered highly unlikely that the intakes (which are <0.3 m/sec velocity) or the outfalls will have any effect on the environment.

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Existing Marine Environment Section 2

2 Existing Marine Environment

2.1 Bathymetry The bathymetry of the Cape Preston region is shown on Figure 2-1. The region has extensive intertidal areas, particularly to the south and south-east of Cape Preston, and a shallow nearshore platform that extends to the south-west of Cape Preston for a few kilometres but extends to the north-east some 30 km in the vicinity of Eaglehawk Island. This platform to the east of Cape Preston is very shallow and drains Regnard Bay. It contains two small islands (SW and NE Regnard) and shoals. The Maitland River drains into Regnard Bay and the intertidal areas along this stretch of coast support large stands of mangrove habitat.

To the west of Cape Preston lies a shallow embayment known as Fortescue Roads. The Fortescue River discharges at the base of this embayment. The river is located some 23 km to the south-west of Cape Preston, and is the closest river to the Cape. Both the Maitland and the Fortescue Rivers drain large areas of hinterland, but only flow occasionally in response to cyclonic downpours over the hinterland. On such occasions they discharge large volumes of fresh and highly turbid silty waters to the nearshore environment. Further to the west lies a shallow promontory on which occur a number of small islands and shoals (e.g. Fortescue and Steamboat Islands). This promontory runs to the north and effectively borders Fortescue Roads to the west.

Fortescue Roads drains northward into a large basin where water depths extend to -16 m CD. This basin is relatively flat and slopes gently from the shore out. It is partly enclosed to the north by a low subtidal ridge at -11 m CD. This ridge supports a number of shoals and banks (e.g. McLennan and Cod Banks).

Preston Island is located approximately 1.2 km to the north-west of Cape Preston and is located near the tip of the shallow nearshore platform referred to earlier. At low spring tide it is barely separated from the mainland by very shallow water (<1 m chart datum (CD). The seabed is relatively shallow (<8 m CD) south-west of Preston Island, however, immediately north to north-west of Preston Island (~300 m offshore) the seabed drops rapidly to over 13 m CD, and deep navigable waters (>20 m) occur some 11 km to the north (URS 2007).

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Section 2 Existing Marine Environment

Figure 2-1 Cape Preston Bathymetry

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Existing Marine Environment Section 2

2.2 Climate

Cape Preston is located at 20°51’0 S and 116°12’0 E. Synoptically, the region is dominated by relatively diffuse extra-tropical high-pressure systems, although during the Austral summer months, the influence of tropical low- pressure systems increases. The meteorology of the North West Shelf is controlled by two main seasons, referred to here, respectively as ‘cool’ and ‘warm’; there are short transition seasons between these two main seasons. The cool season typically extends from May to August, with the warm season normally from October through March (Pearce et al. 2003).

Overlying the prevailing seasonal winds is local circulation brought about by land/sea breeze cells. These cause a regular diurnal variation in the strength and direction of winds, for approximately five to twenty kilometres respectively landward and seaward from the coast. Although these cells are strongest during the warm season, they may occur at any time of year. The warm season is largely coincident with the tropical cyclone season, which may produce intense, mobile low-pressure systems. These are capable of producing extreme winds and are generally associated with the most extreme rainfall, wave and surge conditions across the North West Shelf (GEMS 2008a).

During the cooler months a high-pressure ridge controls the winds over the region; this ridge is a persistent feature over the southern part of Western Australia. The ridge drives easterly winds across the Pilbara shelf region. Frontal systems moving through mid latitudes periodically erode the ridge; winds then shift to the north- east, with subsequent rotation through south-west to south-east following frontal passage. A new high pressure will then re-establish the pattern; during this phase periods of more persistent and stronger easterly winds can be expected to influence Cape Preston.

During the warmer months, the sub-tropical ridge migrates southwards and the dominant synoptic feature is a permanent heat trough that develops inland from the Pilbara coast. This pattern produces quasi-permanent south-west wind flow across the shelf region. Fluctuations in the intensity and location of the heat trough as well as diurnal and local topographic influences affect day-to-day variations in wind direction and speed within the general south-west flow (GEMS 2008a)

Monthly variation of the wind climate has been described by GEMS (2008a) using the Bureau of Meteorology MesoLAPS dataset. The corresponding monthly wind roses are presented in Figure 2-2 for the Cape Preston site.

On average, five tropical cyclones pass through the west Australian region each year, although this may be highly variable on a year-to-year basis. Cyclones are typically generated offshore from the Kimberley, although they may be generated across a broader range of longitudes under suitable conditions.

It is well known that the Cape Preston–Mardie Station region is subject to intense cyclonic activity, with the most severe storm on record, Severe Tropical Cyclone Vance (1999) causing extensive coastal inundation between Onslow and North West Cape. In 1989 another severe cyclone (Orson) crossed the coast close to Cape Preston. More recently, during the 2005-06 season, two cyclones (Clare and Glenda) also crossed the coast in the Cape Preston region. Figure 2-3 shows the cyclone tracks in the vicinity of Cape Preston since 1950 (GEMS 2008a).

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Section 2 Existing Marine Environment

Figure 2-2 Cape Preston Monthly Wind Roses

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON

Existing Marine Environment Section 2

Figure 2-3 Cyclone Tracks in the Vicinity of Cape Preston 1950-2008

2.3 Tidal Water Levels Water levels have been monitored at Cape Preston since October 2006 by GEMS (2008a) on behalf of Sandwell Australia. This information has been harmonically analysed to determine principal tidal constituents and corresponding tidal planes. The monitoring has determined that Cape Preston experiences semi-diurnal tides, with a lowest to highest astronomical tidal range of 4.75 m. This is similar, but slightly smaller than the estimated tidal regime for Dampier, which is the nearest standard port noted in the Australian Tide Tables (Department of Defence 2008).

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Section 2 Existing Marine Environment

Table 2-1 Tidal planes at Cape Preston compared with those at Dampier

Reference Cape Preston Dampier Level (to the nearest 0.05 m) (to the nearest 0.1 m)

HAT (Highest Astronomical Tide) 2.35 2.5

MHWS (Mean High Water Springs) 1.75 1.8

MHWN (Mean High Water Neaps) 0.50 0.5

MSL (Mean Sea Level) 0.0 0.0

MLWN (Mean Low Water Neaps) -0.50 -0.5

MLWS (Mean Low Water Springs) -1.65 -1.9

LAT (Lowest Astronomical Tide) -2.40 -2.6

2.4 Currents The dominant influence on the circulation in the waters off Cape Preston is the North West Shelf tides and the regional winds. Tides are relatively strong off Cape Preston with a typical semi-diurnal and spring-neap behaviour and a spring tidal range of 4.75 m. Water movements in the region during spring tides are more influenced by tidal currents than local wind conditions. Surface current velocities during spring tides can reach 0.75 m/s (1.5 knots) whereas during neap tides the peak current velocities are typically 0.25 m/s (0.5 knots).

There is no evidence of sustained stratification in the waters off Cape Preston from the 12 months of data recorded on site (GEMS 2008a). The combination of relatively strong tidal currents, episodically strong winds producing wave action and surface currents and the relatively shallow bathymetry around Cape Preston tends to limit the opportunity for stratified layers to develop.

The majority of the flood tide reaches Cape Preston from the open ocean by going around the Montebello Islands and then flowing southwards towards the coast. When the flood tide reaches Cape Preston it splits around the Cape with flow occurring to the south-west and to the south-east along the coast. The ebb tide, whilst not being the exact converse of this process, generally reaches the open ocean by flowing north to northwest around the Montebello Islands.

The dominant mixing and dispersion mechanism off Cape Preston is the strong and varying tidal currents and the episodic influence of strong surface winds.

The dominant flushing mechanism is the ebb tide which generally flows north-north-west from the site. The analysis of the Acoustic Doppler Current Profiler (ADCP) data (GEMS 2008a) also highlights a relatively strong residual current to the north-east driven by the south-westerly winds and the ebb tide. 2.5 Wave Climate Descriptions of the regional wave climate are available from other studies across the North West Shelf (Pearce et al. 2003; Metocean Engineers 2004). Waves along for the North West Shelf have been identified as coming from four sources:

• Southern Ocean swell, propagating past North West Cape

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Existing Marine Environment Section 2

• Winter easterly swell generated across the Timor Sea

• Locally generated wind waves

• Wind waves generated by tropical cyclones

GEMS (2008a) deployed two ADCP offshore from Cape Preston for the Central Block Project from October 2006. The wave measurements obtained by the Acoustic Doppler Current Profiler (ADCP) have been used for validation of a hindcast wave model, which was applied over the period 2001 to 2005 (GEMS 2008 a). Results of the modelling have been used in this report. As the hindcast provides limited information on the frequency distribution of extreme cyclonic waves, dedicated modelling was undertaken to produce a synthetic cyclone database and in turn examine cyclonic conditions.

The wave climate during the summer period reflects the prevailing westerly winds, with waves generally approaching from the northwest (Figure 2-4).

Figure 2-4 Hindcast wave conditions at nearshore Cape Preston February 2001-2005

Wave conditions during winter are more variable, reflecting the wider range of potential wave sources. There is a general rotation towards the east, with wave approaching more from the north or north-north-east (Figure 2-5).

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Section 2 Existing Marine Environment

Figure 2-5 Hindcast wave conditions nearshore Cape Preston July 2001-2005

2.6 Coastal Processes Cape Preston is exposed to a relatively mild ambient wave climate, typically less than 1 m significant wave height, which is predominantly from the west-north-west during the warm season and from the north to east during the cool season. The effect of tropical cyclones is episodic, with the capacity to produce waves from any offshore direction depending on the path of the system. The most severe metocean conditions are produced by cyclones located approximately 20 to 60 km west of Cape Preston, causing extreme wave and surge conditions. These conditions have been derived from hindcast models which indicate a significant wave height up to 6.3 m and a 4.5 m surge with a 1 in 100 year average recurrence interval (GEMS 2008a).

The structure of Cape Preston and its adjacent coast is largely determined by the presence of its rock features, including the basalt outcrop that forms the Cape and the limestone shore platform extending around the Cape and adjacent beaches. These features provide resistance to the ambient wave climate and moderate to strong tidal currents that affect the region. The shelter provided by the rock platform is potentially less effective during cyclone events, where the combination of high waves and storm surge is capable of rapid redistribution of large volumes of beach sediment (GEMS 2008d).

Active sediment transport patterns have been inferred on the basis of the present coastal morphology, historic aerial imagery and interpretation of available metocean data. The regional structure suggests a net movement of sediment towards Cape Preston, notably with supply from the Fortescue River during cyclonic flooding. This material accumulates on the western side of the Cape, as a series of low profile dunes, Preston Spit (Figure 2-6) and a complex structure of shoals across the extensive rock platform.

Under ambient summer conditions, there is a general low volume northward sediment transport along the outer edge of the shoals, which is reversed under northerly conditions that occur occasionally throughout the year. Instability of the western beach has been observed over the historic period and is further evidenced by the loss of a mangrove stand on the northern part of the beach. However, it appears likely that this destabilisation is a combination of marine and fluvial sediment transport (GEMS 2008d).

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Existing Marine Environment Section 2

Cape Preston and Preston Island are largely bare of sediment, suggesting a limited supply. This reflects a general erosive tendency for the Cape, due to its exposure to strong tidal currents and waves from west through east. Extensive storm deposits including cobbles and boulders were observed high on the beach face; suggesting highly energetic conditions can be experienced during extreme events. The presence of a sandy ‘tail’ on Preston Island on aerial imagery since 1966 suggests that sediment occasionally bypasses the Cape.

The beach to the east of Cape Preston is controlled by rock features, including basalt ridges that act as groynes (northern beach Figure 2-6). These features are fully saturated with sediment on their western side, suggesting a net eastward sediment transport. An extensive scarp runs along the high frontal dune, indicating erosion approximately within the last five years. Recovery of the beach system is apparently low, with only a small ridge of material deposited above the tidal berm. Despite these features, the beach has remained largely stable within the 40 year history of available aerial photography. The beach on the eastern side (eastern beach Figure 2-6) of the Cape has also been stable over the historic period, although it exhibits signs of seasonally alternating northward and southward alongshore transport, with net southwards movement. The southern limit of the beach (eastern spit Figure 2-6) is controlled by an eastward running rock platform, which apparently represents the limit of sheltering provided by Cape Preston. Consequently, this beach has a structurally limited capacity, and any excess material is readily transported eastwards to the tidal flats and Eramurra Creek floodplain (GEMS 2008d).

Figure 2-6 Cape Preston geomorphic components

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Section 2 Existing Marine Environment

2.7 Water Quality Available literature and monitoring data which describe the physical characteristics and concentrations of chemical elements in the water are reviewed below. The results of a preliminary investigation of water quality at Cape Preston are presented in Appendix A. 2.7.1 Temperature, salinity, pH and oxygen The following paragraph is a summary of information provided by CALM (2005) in relation to the former (proposed) Cape Preston Marine Management Area.

The waters of the proposed area are relatively undisturbed by anthropogenic sources. Near-shore water movements and mixing patterns in the Dampier Archipelago/Cape Preston region are driven primarily by large tidal ranges, local currents and winds, but are also influenced by seabed topography and the steering effect of islands and reefs. Sea-surface temperatures within the Dampier Archipelago range from about 18ºC in winter to 31.5ºC in summer, with near-shore waters having a greater seasonal temperature range than the offshore waters. The smallest range and lowest salinities (35.1 to 36.1 ppt) occur offshore at the 20 m contour, and the largest range and highest salinities (35.45 to 37.1 ppt) occur inshore within 2 km of the Burrup Peninsula. Salinity and temperature differences between the nearshore and mid-shelf regions are expected to drive gentle cross-shelf circulation in the region.

Monitoring data collected by URS in 2007 (Table 2-2) at two locations nearshore to Cape Preston identified that waters are generally supersaturated with Dissolved Oxygen (>100%) and pH values are high (>8.1). These results have been corroborated by a survey undertaken during a neap tide on 16 May 2008 (Table 2-3) at the brine outfall site. In fact, the pH values from this survey were all higher than 8.6.

Table 2-2 Mean water quality characteristics – 2007

Temp. DO Turbidity Salinity DO Cond Site Date (oC) (mg/L) pH (NTU) (ppt) (% Sat) (ms/cm)

Intake Location 27 Feb 07 30.60 5.96 8.21 2.69 36.94 99.99 54.58

22 Mar 08 30.20 6.77 8.20 2.28 36.14 112.85 54.81

ADCP 29.94 6.87 8.18 2.46 35.90 113.94 54.48

Intake Location 4 Apr 07 30.18 8.74 7.62 22.35 34.36 144.05

ADCP 30.0 8.29 7.81 22.43 36.97 136.13

Intake Location 19 Apr 07 30.24 6.87 8.40 22.43 37.34 115.16

ADCP 30.23 6.85 8.39 2.08 37.41 115.31 56.52

Intake Location 7 Jun 07 23.49 8.81 8.11 3.45 53.98

ADCP 23.41 8.74 8.12 3.21 53.74

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Table 2-3 Physical characteristics of the water column in the vicinity of the brine outfall – May 2008

Depth Temp. DO pH Turb. Salinity DO SAT M °C mg/L NTU ppt % Sat 0.50 26.55 6.63 8.64 0.40 35.10 100.00 1.50 26.55 6.63 8.64 0.40 35.10 100.00 2.00 26.55 6.63 8.64 0.40 35.10 100.00 3.00 26.54 6.68 8.64 0.40 35.10 100.80 4.00 26.55 6.66 8.64 0.40 35.20 100.50 5.00 26.54 6.71 8.64 0.60 35.10 101.20 6.00 26.55 6.67 8.64 0.50 35.20 100.70 7.00 26.56 6.71 8.64 0.80 35.20 101.30 8.00 26.55 6.71 8.64 1.20 35.20 101.20 9.00 26.55 6.64 8.64 1.50 35.10 100.10

Table 2-4 Dissolved metal concentrations in water in the vicinity of the brine outfall site

Mean (n=3) Surface Mean (n=3) Bottom ANZECC Guideline Metal Concentrations Metal Concentrations (mg/L) 99% species (mg/L) (mg/L) protection

Aluminium 0.005 <0.005 0.0005* Arsenic 0.0016 0.0016 N/A Beryllium <0.001 <0.001 N/A Cadmium <0.0001 <0.0001 0.0007 Chromium <0.001 <0.001 N/A Copper <0.001 <0.001 0.0003 Lead 0.008 <0.001 0.0022 Manganese <0.001 <0.001 0.08* Nickel <0.001 <0.001 0.007 Zinc <0.001 <0.001 0.007 Iron <0.005 <0.005 N/A Bromide 94.3 82 N/A Barium 0.007 0.007 N/A Strontium 6.53 7.56 N/A Boron 5.63 5.6 5.1* Mercury <0.0001 <0.0001 0.0001 *Low reliability trigger value Guideline below laboratory detection limits Exceedance of guideline

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2.7.2 Turbidity and total suspended solids According to Halpern Glick Maunsell (2006), turbidity in the region is generally high, due to the episodic high volume river flows, dominant marine sediment types, strong local winds, large tides and common occurrences of cyanobacterial blooms (Trichodesmium sp.). Turbidity is typically higher in the shallow near-shore areas than in the deeper sites further offshore, and can vary considerably on a spatial scale due to localised re-suspension of sediments and temporally over hours and days depending on wind and tide.

Turbidity data collected by URS ranged from 0 to 23 NTU. The high turbidity readings (>20 NTU) are believed to be associated with an algal bloom event (biological cause – see above) and not caused by a change in tide, water depth, sediment structure, wind and current situations or river inflow. The latter are the observed physical causes responsible for significant changes in turbidity on a spatial and temporal scale.

TSS data obtained by URS during 2007 and 2008 indicate that ambient concentrations range between 2 mg/L and 10 mg/L.

TSS and turbidity can change significantly throughout cyclonic events. As no cyclone approached the area during the time of investigation no data is available for such an event. 2.7.3 Nutrients and trace elements Nutrient concentrations obtained by Halpern Glick Maunsell 2002 were all found to be slightly above ANZECC & ARMCANZ (2000) guideline values. This finding supports the assumption that the project area is biologically productive.

Regional studies undertaken by the DEC identified that Pilbara waters generally had very low concentrations of metals. Localised elevations were identified adjacent to industrial centres and ports. Overall, the environmental quality guidelines for a very high level of ecological protection (99% species protection) was met throughout the sampled area, with the exception of the inner harbour at Port Hedland, where copper and zinc levels were elevated above background concentrations, but below the 95% species protection guidelines (representing a high level of ecological protection).

Samples collected by URS in 2008 (Table 2-4) showed results similar to those reported by DEC. With the exception of two elements (lead and boron) all samples were below recommended ANZECC & ARMCANZ (2000) guideline values for 99% species protection (very high level of protection) or below laboratory detection limits. It should be noted that the 99% species protection guidelines for aluminium and copper are below the laboratory detection limits of the NATA registered laboratory engaged to analyse the samples. 2.7.4 Sediment quality Surface marine sediments obtained in 2002 and 2004 by Halpern Glick Maunsell (2006) were analysed for metals, nutrients, organic and calcium carbonate percentage, TBT, hydrocarbons and particle size. Sediments were found to have inorganic contents ranging from approximately 4 to 40 percent. Calcium carbonate ranged from 15 to 40 percent. Arsenic levels were found to be above ANZECC trigger values (also found in tissues of carnivorous fish from the area). TBT and hydrocarbons were all below detection limits.

In 2006, a sediment quality survey was undertaken by DEC (2006) at six locations in the Pilbara region to determine concentrations of a range of selected metal and organic chemicals under natural background conditions. This work was undertaken to provide a baseline for evaluating anthropogenic changes or trends around regional centres of development. Metal and metalloid concentrations were found to be similar to other areas in northern Australia and in most cases concentrations were below the recommended ANZECC guideline

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Existing Marine Environment Section 2 values. However, the arsenic and iron concentrations at one site (Ashburton River) were very high and it has been assumed that this is due to the geology in this area. At none of the sites organic chemicals could be detected (DEC 2006). 2.8 Distribution of marine biota and benthic habitats 2.8.1 Macroscale biogeography Cape Preston is situated on the north-western coast of Australia, in the northern Australian tropical zone. The zone is continuous with the vast Indo-West Pacific biotic province that extends from about 30°N to 30°S of the equator and from the east coast of Africa across the entire tropical portions of the Indian and Pacific Oceans to Hawaii. A few species extend even to the west coasts of central and South America (Wilson & Allen 1987).

Most marine invertebrates and fish, probably more than 95% of the species, have planktonic larvae that live in the water column for periods ranging from a few days to a year or more. This is a distributional phase in the life cycle during which the larvae are moved about by currents and wave action. Even species that lack a planktonic distributional phase in their life cycle are able to move considerable distances by rafting on floating logs, Sargassum mats, etc.

Similarly, marine and intertidal plants such as seagrasses and mangroves are able to move over time over considerable distances by dispersal of seeds or propagules by tides and ocean currents. Hence the seagrass species that occur along the Pilbara coast have, in general, a widespread distribution around the northern coast of Australia and adjacent tropical waters. However, community structure and composition of seagrasses can vary considerably depending on regional and local scale conditions.

The net effect of the patterns of marine biogeography is that species in the Cape Preston area are generally distributed for thousands of kilometres along the northern Australian coastline, and into countries to the north such as Indonesia, Papua New Guinea and the Philippines (Wells 1990). Some species occur widely across the entire Indo-West Pacific. Relatively few species have restricted ranges, and those that do are on the scale of tens or hundreds of kilometres. 2.8.2 Mesoscale regionalisation At the Mesoscale (IMCRA 1998), that is broad regional ecosystem scale (regions extending in area between 3,000 km2 and 240,000 km2) the project occurs within two regions, Pilbara Offshore and Pilbara Nearshore.

Pilbara Nearshore, with an area of 13,861 km2, covers the waters between the shoreline and 10 m depth contour and extends from North West Cape to Cape Keraudren. The intertidal and shallow subtidal habitats is described as supporting a high diversity of infauna on mudflats and sandflats associated with fringing mangals in bays and lagoons. The water is described as highly turbid with a large tidal range. Fringing coral reefs occur around some of the islands.

Pilbara Offshore, with an area of 41,491 km2, comprises waters seaward of the 10 m depth contour between North West Cape and Cape Keraudren. The water is described as less turbid than in the nearshore region and there are significant differences in marine ecosystems. It includes coral reef ecosystems with Indonesian and Pacific affinities.

Cape Preston occurs roughly in the middle of this broad regional ecosystem type.

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Section 2 Existing Marine Environment

2.8.3 Marine flora The Indicative Management Plan for the Proposed Dampier Archipelago Marine Park and Cape Preston Marine Management Area (CALM 2005) describes the marine flora of the region as follows:

“Within the Cape Preston area, macroalgae (seaweeds) dominate submerged limestone reefs and also grow on stable rubble and boulder surfaces. These communities are most commonly found on shallow limestone pavement in depths less than 10 m. Brown algae are the most abundant group of algae in the region, with Sargassum sp., Dictyopteris sp. and Padina sp. being the dominant species. The most common green algae are the articulate coralline Halimeda sp, while prominent red algal species include crustose corallines, non- corallines and algal turf. Seagrass occurs in the larger bays and sheltered flats of the region. Six species of seagrass are present on the subtidal soft sediment habitats, these being Cymodocea angustata, Halophila ovalis, Halophila spinulosa, Halodule uninervis, Thalassia hemprichii and Syringodium isoetifolium. Seagrasses do not form extensive meadows within the proposed reserves, but rather form interspersed seagrass/macroalgae beds.

The most significant areas of seagrass are found between Keast and Legendre islands and between West Intercourse Island and Cape Preston. Macroalgae and seagrasses are important primary producers, trapping light energy from the sun and making it available to the ecosystem. They also provide important habitats for molluscs, sea urchins, sea stars, sea cucumbers, crabs and fishes. Marine turtles feed on algae and seagrass, and the ephemeral seagrass typically found in the area is likely to be the preferred food source for the resident dugong population “ 2.8.4 Sessile marine biota Fauna of the shallow water limestone reefs and platforms include hard and soft corals, sponges, ascidians, fan worms, molluscs (octopus, gastropods [snails], and bivalves), crustaceans (crabs, rock lobsters), urchins and seastars.

Fifty species of hard coral representing 11 families have been reported off Cape Preston (Campey & Gilmour 2000). This compares with 229 species reported from the Dampier Archipelago (Griffith 2004). All species reported by Campey and Gilmour (2000) have been reported from the Dampier Archipelago and other areas of Australia. The dominant families, in terms of species recorded, include Acroporidae, Poritidae and Faviidae. Taxa, such as Turbinaria, Caulastrea and Euphyllia, which are typically associated with turbid nearshore water (Veron & Marsh 1988) were also present at Cape Preston. As with many nearshore areas fringing the Pilbara coast, most of the coral assemblages at Cape Preston do not form true coral reefs because erosion exceeds accretion. Instead, corals form assemblages on rock pavement without contributing greatly to the substratum. However, there are some true coral reefs at Cape Preston where living coral cover is very high and based on dead coral substratum. These are discussed in the following section.

Veron and Marsh (1988) identified 18 broad coral localities in Western Australia. The coral reefs off Cape Preston form part of the location referred to by Veron and Marsh (1988) as the Dampier Archipelago. All coral species recorded in the Dampier Archipelago (Veron & Marsh 1988) and most in Western Australian waters are not endemic, rather they are found throughout tropical Australia and, in many cases, more widely throughout the Indo-Pacific region. The wide distribution of most Western Australian scleractinian corals suggest that dispersal mechanisms, availability of suitable colonising substrate, and exposure to wave energy have major influences on coral species composition and distribution along the Western Australian coastline.

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Existing Marine Environment Section 2

2.8.5 Benthic habitats The distribution of marine benthic habitats in the Cape Preston region has been mapped by CALM (2000), Maunsell (2006) and URS (2007). Figure 2-7 presents the current distribution of marine habitats in the vicinity of Cape Preston as mapped by URS (2007). Mapping of the distribution of marine habitats in the vicinity of Cape Preston is partly based on a review of past mapping in the area, but is mainly based on recent field surveys and aerial inspections by URS.

Dense areas of high coral cover are sparsely distributed in the region, whilst areas of low coral cover tend to occur as a thin border along steep slopes that descend from shallow algae-dominated pavements around islands to a deep sandy seafloor.

The nearest major reefs to Cape Preston which support high live coral cover are located as follows:

• approximately 3 – 5 km to the south-west of Cape Preston

• 4 km to the east-north-east of Cape Preston on the south-east end of SW Regnard Island

• 5 km east of Cape Preston.

These reefs support >50% and in parts up to 100% live coral cover, and are comprised primarily of large colonies of massive species such as Porites, Favites, Lobophylia and Goniastera. These reefs are obviously old and have survived many cyclones although evidence of cyclone damage is abundant. Figure 2-8 shows the reef located at the southern end of SW Regnard Island at LAT. Figure 2-9 shows the reef which occurs about 5 km south-west of Cape Preston also at LAT.

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Figure 2-7 Cape Preston Benthic Habitats

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Plate 2-2 LAT Aerial Survey October 2007 – close-up of high cover coral community north of Preston Spit

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2.9 Marine Fauna Marine and intertidal fauna appearing in either Schedule 1 of the Wildlife Conservation Act 1950, listed under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 or DEC’s Priority Fauna List either are known to occur in near coastal waters or have been recorded locally (refer to Paragraph 4.6 for further information). 2.9.1 Marine turtles Pendoley Environment (2006) conducted a review of turtle habitat usage reports for the Cape Preston locality on behalf of URS. Sea state and prevailing weather conditions combine to erase evidence of turtle breeding activities at Cape Preston; consequently surveys have had to rely mostly on live sightings rather than remaining signs as used in surveys elsewhere. However, available survey information obtained during three separate seasons indicates that the beaches of Cape Preston are utilised less intensely for breeding activities (approximately four animals per km) than, for example, on the Pilbara mainland nesting area on Cowrie Beach (west of Port Hedland – approx. 50-150 animals per km). Furthermore, the results suggest the northern end of the western beach is a nesting area for hawksbill turtles (Eretmochelys imbricate), the eastern beaches are used by the green turtle (Chelonia mydas) and south- western beaches by flatback turtles (Natator depressus). 2.9.2 Dugongs In the Dampier Archipelago/Cape Preston region, small numbers of dugongs (Dugong dugon) have been sighted in the shallow, warm waters in bays and between islands, including at East Lewis Island, Cape Preston, Regnard Bay, Nickol Bay and west of Keast Island. Current knowledge on the size of the population, distribution, migratory habits and regional and local importance of the Dampier Archipelago/Cape Preston area for dugongs is limited.

A review of recent literature indicates that moderate concentrations of dugongs were observed in the region between Exmouth Gulf and De Grey River during shoreline surveys in the 1980s, with most animals observed in areas such as Mangrove and Passage Islands, Regnard Bay, Nickol Bay and within the Dampier Archipelago (Prince et al. 1981; Prince 1986). In April 2000, a quantitative aerial survey of this area recorded 2,046 (± s.e. 376) dugongs at an average density of 0.10 dugongs per km2. Most of the dugongs were in the locations identified from the earlier surveys and incidental reports of sightings or strandings (Prince et al. 1995; Marsh et al. 2002).

Dugong feeding trails have been observed in dense seagrass meadows of Halodule and Halophila, between Middle and North Mangrove Islands (Pendoley & Fitzpatrick 1999). This region has extensive areas of shallow water, extending to the seaward side of Barrow Island and the Monte Bello Islands (Marsh et al. 2002). In surveys of Exmouth Gulf in October and November 2004, the majority (76%) of dugong herds sighted were in shallow (<6 m) water (Oceanwise 2005). Regional quantitative surveys indicate a minimum population estimate

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Existing Marine Environment Section 2 of approximately 1,000 individuals in Exmouth Gulf during winter (Oceanica 2005). Individual dugong have been occasionally sighted off the west coast of Cape Preston and SW Regnard Island during boat based field surveys carried out by URS during December 2006, June 2007, and May 2008 for CITIC Pacific Mining Management’s (CPMM) Sino Iron Project at Cape Preston (Ian LeProvost pers. comm.). Further information regarding the status of the dugong population in the region is provided in Appendix B. 2.9.3 Other fauna The humpback whale migrates along the Western Australian Coast in winter and early spring. Along parts of the migratory route there are narrow corridors and bottlenecks resulting from physical and other barriers where the majority of the population passes close to shore (i.e. within 30 km of the coastline). These habitat areas are important during the time of migration and in Western Australia include areas around Geraldton/Abrolhos Islands, and Point Cloats to North West Cape. Calving takes place of the Southern Kimberley between Broome and the northern end of Camden Sound and there are resting areas located around Exmouth Gulf, Shark Bay and Geographe Bay (Department of Environment and Heritage 2005). The whales are not known to aggregate in the waters offshore Cape Preston, but it is possible that individuals, as well as small pods of dolphins pass through the area.

It further should be noted that seasnakes have been observed to occur in the proposed area and Wells and Walker (2003) reported the occurrence of six different species in the Dampier Archipelago.

2.10 Social values and uses The shallow waters of Regnard Bay to the east of Cape Preston have acknowledged conservation value as do the nearshore islands which comprise the Sandy Islands Nature Reserve.

The waters and shallow marine habitats of Regnard Bay are fished recreationally by low numbers of visitors from Dampier and by itinerant “grey nomads” who occupy the 40 mile beach camp site during winter months. The waters on the west side of Cape Preston are similarly fished recreationally by visitors from Panawonica and by grey nomads who occupy the Fortescue River campsite during winter.

The deeper waters to the west of Cape Preston are used occasionally by Onslow based prawn trawlers. The Onslow Prawn Managed Fishery operates along the western part of the North West Shelf and targets western king prawns (Penaeus latisulcatus), brown tiger prawns (Penaeus esculentus), endeavour prawns (Metapenaeus spp.) and banana prawns (Penaeus merguiensis) using otter trawl. The governing legislation/fishing authority is the Onslow Prawn Fishery Management Plan 1991 and the Onslow Prawn Managed Fishery Licence. Cape Preston falls in both Fishing Area 3 and the Fortescue Nursery Area of the Onslow Prawn Managed Fishery.

There are two aquaculture lease sites within the vicinity of Cape Preston (Figure 2-10). One is presently operational and is involved in the culture of the winged oyster (Pteria penguin). The other is not currently operational. The operational Pteria penguin lease is believed to be seeking approval for expansion.

The immediate vicinity of Cape Preston has been declared a port site and port limits have been established. The mainland immediately adjacent Cape Preston, Regnard Bay and the Fortescue River has been zoned for industrial use and are covered by mining leases.

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Section 2 Existing Marine Environment

Figure 2-8 Designated marine social uses in the vicinity of Cape Preston

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Relevant Environmental Factors Section 3

3 Relevant Environmental Factors

3.1 EPA Guidance Statement No. 29: Benthic Primary Producer Habitat Protection for WA’s marine environment The WA EPA Guidance Statement No. 29 (EPA 2004) sets out a framework for the assessment of proposals that may impact on Benthic Primary Producers (BPP) and the habitats that can or do support such communities, termed Benthic Primary Producer Habitats (BPPH). The Guidance considers that BPP are ‘predominantly marine plants (e.g. seagrasses, mangroves, seaweeds and turf algae), but include invertebrates such as scleractinian corals...’.

In this Guidance Statement, the EPA has provided a set of principles to be applied by proponents and the EPA when considering development proposals that may result in removal or destruction of, or damage to, marine benthic primary producer communities or the habitats which support them. The EPA uses the term Benthic Primary Producer Habitat (BPPH) throughout this Guidance Statement to mean the ecological units that are BPPH including the dominant BPP communities they support.

The EPA has also defined six categories of marine ecosystem protection and provided guidance on the amount of BPPH that may be lost due to development as a percentage of BPPH within a defined management unit for each category. These percentages are termed ‘cumulative loss thresholds’ that, if exceeded, will be used by the EPA as indicative of potential non-acceptability. However, given the difficulty of reliable measurement of the area of some BPPH and considering the difficulty of quantifying the ecological significance of their loss, these thresholds will not be used as rigid limits. The acceptability of BPPH damage/loss will in all cases be a judgement of the EPA based primarily on its assessment of the overall risk to the ecosystem integrity within a defined management unit if a proposal were allowed to be implemented.

The six categories of marine ecosystem protection and their corresponding cumulative loss thresholds are summarised in Table 3-1.

Table 3-1 Cumulative loss thresholds for BPPH within defined management units for six categories of marine ecosystem protection

Cumulative loss threshold* Category Description (percentage of original BPPH within a defined management unit) A Extremely special areas 0% B High protection areas other than above 1% C Other designated areas 2% D Non-designated area 5% E Development areas 10% F Areas where cumulative loss thresholds have 0% net damage/loss (+Offsets) been significantly exceeded

Thresholds will be applied only after proponents can demonstrate to the EPA that all options to avoid/minimise damage/loss of the BPPH have been considered.

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Section 3 Relevant Environmental Factors

The Guidance Statement’s risk-based approach to assessing any implication for BPPH ecosystem integrity sets out several steps. The first is the definition of a ‘Management Unit’ for the purposes of applying the EPA Guidance. The Guidance considers that “a Management Unit would normally be approximately 50 km² (e.g. a rectangular area defined by a 10 km stretch of coastline extending 5 km offshore” (EPA 2004). The purpose of the Guidance is to focus the mind of proponents on the need to ensure that a proposed Management Unit is reasonable and defendable when considering the impact of a proposal on the ecological value and function (integrity) of the habitat of a specified benthic primary producer. As set out by the EPA, the Management Unit needs to be a geographical area which provides the most effective boundaries for the management of cumulative environmental impacts on ecological values and functions.

An assessment of BPPH loss from the construction of the proposed Cape Preston Port and shipping channel in the context of Guidance Statement No. 29 was undertaken as part of the Marine Management Plan for that proposal. An assessment of potential impacts from the construction of the brine outlet and diffuser is provided in section 4. However, as the majority of the pipeline will be trenched within the proposed harbour entrance channel, with only a small proportion of the pipeline route to be constructed in undisturbed habitat with no BPPH significance, a formal assessment of BPPH loss is considered not warranted and has not been undertaken for this project. 3.2 The Proposed Regnard Marine Management Area The proposed Regnard Marine Management Area is mooted for the mainland coastal areas extending from Eaglehawk and West Intercourse Islands westwards to SW Regnard Island (Figure 3-1). This management area replaces the former proposed Cape Preston Marine Management Area (CALM 2005) that extended to the west of Cape Preston as far as the Fortescue River mouth. The westward extension of the proposed Cape Preston Marine Management Area has now been deleted as this included proposed port facilities and areas covered by State Agreements Acts (Dr F Stanley, DEC, pers. comm. 2007).

The Department of Environment and Conservation (DEC) is currently preparing for the formal gazettal of the proposed Regnard Marine Management Area under the provisions of the Conservation and Land Management Act 1984. A draft management plan is also being prepared and will be released following the creation of the reserve. The DEC is anticipating that this will occur mid 2008 (Dr F Stanley, DEC, pers comm. May 2008).

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Relevant Environmental Factors Section 3

Figure 3-1 Proposed Regnard Marine management Area

3.3 Pilbara Coastal Waters – Environmental Values and Environmental Quality Objectives In late 2004, the former Department of Environment (now DEC) ran a series of targeted workshops on the establishment of Environmental Values (EVs) and Environmental Quality Objectives (EQOs) for the State marine waters from Exmouth Gulf to Cape Keraudren. This consultation also included comment on the application of these EVs and EQOs to these waters.

The results of consultation undertaken and recommendations to the EPA are published in Pilbara Coastal Water Quality Consultation Outcomes – Environmental Values and Environmental Quality Objectives (DEC 2006). The recommendations of this report have now been endorsed by the EPA as a framework for environmental impact assessment, waste discharge regulation and natural resource management. The report and associated ecological protection maps should act as a guiding document until such time as more formal government policy, such as a State Environmental Policy, is developed (K McAlpine, DEC, pers comm. April 2008).

The EVs and their associated EQOs as endorsed by the EPA are as follows:

• Ecosystem Health (ecological value)

— Maintain ecosystem integrity.

• Recreation and Aesthetics (social use value)

— Water quality is safe for recreational activities in the water (e.g. swimming)

— Water quality is safe for recreational activities on the water (e.g. boating)

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Section 3 Relevant Environmental Factors

— Aesthetic values of the marine environment are protected.

• Cultural and spiritual (social use value)

— Cultural and Spiritual values of the marine environment are protected.

• Fishing and Aquaculture (social use value)

— Seafood (caught or grown) is of a quality safe for eating

— Water quality is suitable for aquaculture purposes.

• Industrial Water Supply (social use value)

— Water quality is suitable for industrial supply purposes.

In developing the ecosystem health EV, different levels of ecological protection have been developed for application to Pilbara coastal waters, as outlined in Table 3-2. The spatial application of the EVs and EQOs to the waters around Cape Preston is outlined in Figure 3-3. It should be noted that Figure 3-3 shows the former proposed Cape Preston Marine Park, which has now been superseded by the proposed Regnard Marine Management Area.

A Water Quality Management Framework (WQMP) will be developed and applied for the operation of the desalination plant. This framework will follow those objectives and recommendation of the EPA as discussed above. Section 5 provides further information on the proposed WQMP for this proposal.

Table 3-2 Levels of Ecological Protection for the Maintenance of Ecosystem Integrity

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Figure 3-2 Environmental Values and Objectives for Cape Preston Waters

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Section 4 Potential Impacts and their Mitigation

4 Potential Impacts and their Mitigation

This section assesses the potential and actual effects after mitigation of the following activities:

• Construction of the brine outfall pipeline

• Construction of the seawater intake

• Operation of the brine outfall (the discharge)

• Construction and operation of the seawater return outfall

• Cumulative effects of a second brine discharge at Cape Preston

• Effect of construction and operation of brine outfall on EPBC listed species.

4.1 Construction of Brine Outfall Pipeline 4.1.1 Objectives and standards The objective for the construction of the outlet pipeline and diffuser is to ensure there are no significant impacts to sensitive BPPs, or the habitats which support them (BPPH), as a result of construction activities.

Relevant legislation and standards include:

• EPA Guidance Statement No. 29: Benthic Primary Producer Habitat Protection for WA’s Marine Environment 4.1.2 Construction details The preferred brine outfall pipeline is proposed to carry concentrated brine and filter backflush water to a discharge diffuser located approximately 800 m north-west of the proposed Cape Preston harbour, located in 10 m of water at Lowest Astronomical Tide (LAT) (see Figure 2-7).

The outfall pipe will be made from Glass Reinforced Plastic (GRP), and have a nominal diameter of 1.8 m. The majority of the outlet pipeline will be trenched into the seabed of the entrance channel for the Cape Preston harbour and thence into the natural seafloor to the diffuser endpoint. The trench will be some 5 m wide by 3 m deep and will be constructed by barge mounted excavator. The volume of rock that will be excavated will be approximately 2,500 m3. The trench will be backfilled with rock after installation of the pipeline, and the total task is anticipated to take between one and two months depending on the weather. 4.1.3 Potential impacts The construction of the outlet pipeline and diffuser may have the potential to:

• Directly impact sensitive BPPH as a result of trenching activities for the installation of the pipeline.

• Cause a localised decline in water quality as a result of pipeline construction activities, mainly turbidity.

• Indirectly impact sensitive BPPH due to turbidity generated by pipeline construction activities.

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4.1.4 Management and mitigation Careful site selection for the outlet pipeline and diffuser corridor will ensure that sensitive BPPH is not affected as a result of the construction of the pipeline and diffuser.

Benthic habitat mapping conducted for the project area has identified that the pipeline and diffuser is to be located in an area of low environmental sensitivity, mainly consisting of algal dominated limestone pavement and deep sand/silt (see Figure 2-7). These habitats are deemed to be of low sensitivity due to their widespread distribution in the greater region of the project.

The area in the vicinity of the outfall site was inspected by URS in May 2008. This dive survey confirmed that the brine discharge outfall will traverse an area of shallow sand veneered or exposed limestone pavement as shown in Figure 4-1. Where the limestone pavement is exposed, a sponge, feather star and sea-whip garden community of filter feeding invertebrates colonises the seafloor. The sand seafloor is primarily rippled medium- coarse grains over pavement in a thin 1-10 cm veneer.

Plate 4-1 Seafloor in the vicinity of the brine outlet location

An assessment of the known and potential impacts of the construction of the brine outlet pipeline and diffuser has identified that there will be no permanent loss of sensitive BPPH such as coral reef habitat. This has been determined by overlaying the outlet and diffuser configuration onto the benthic habitat map (Figure 2-7), as well as visual inspections of the seabed in the vicinity of the outfall.

Direct Impacts As the majority of the pipeline is to be constructed within the proposed dredged entrance channel to the Cape Preston Port, there will be no direct impacts to benthic habitat as a result of this work. Impacts from trenching activities for the outlet pipeline within the dredged channel will be negligible, as works will be completed in the already disturbed areas of the operating shipping channel and will be undertaken by large excavator which does not create large amounts of turbidity.

The remaining sections of pipeline outside of the dredged channel will be trenched into areas of low environmental sensitivity. The footprint required for installation of the pipeline will be minimised as much as is possible, but is estimated to be a maximum of 5 m in width. Only those habitats within this immediate pipeline

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Section 4 Potential Impacts and their Mitigation corridor will be directly disturbed as a result of the installation of the outlet pipeline. However, backfilling of the trench with rock will create a new “artificial reef” habitat which eventually will be colonised by similar organisms that currently colonise the exposed limestone pavement at that vicinity. In the long term, this ‘reef’ is likely to actually locally increase biological productivity in the region because it will provide a solid substrate for invertebrates and algae to colonise.

Hence the direct impact of the brine outlet pipeline and diffuser footprint will be the modification of seafloor habitat to a more biologically stable and productive state (i.e. from sand to exposed limestone). There will therefore be no long-term loss of benthic primary producer habitat.

Indirect Impacts It is anticipated that trenching and backfilling activities for the installation of the pipeline and diffuser will take approximately 1-2 months to complete. As a result, turbidity generated from trenching activities will be temporary and localised and intermittent given that it will be undertaken by backhoe excavator and will be interrupted by tide and weather.

It is expected that turbidity generated from trenching activities and backfilling activities will be minor and will be restricted to the non-significant habitats in the immediate vicinity of the pipeline corridor, and as such it is deemed that there will be no significant impacts to the surrounding environment, including any sensitive coral habitats in the region. 4.1.5 Alternative outfall pipeline route There is a possibility that the proposed Cape Preston harbour and breakwaters may not be built by the time the Balmoral South Project needs to construct the desalination plant. In such a case, the Balmoral South Project proposes to discharge brine via a pipeline constructed along an alterative route to the preferred option discussed above. If this is to occur, the diffuser of the Central Block Project will not be constructed in the current location, and the diffuser of the Balmoral South Project will be constructed at this site instead. The alternative pipeline route is shown on Figure 2-7.

This alternative route presents the same potential impacts as those discussed above for the preferred outfall pipeline location. The pipeline will be constructed via the same method as discussed above.

Benthic habitat mapping conducted for the project area has identified that the alternative pipeline will be located in an area of low environmental sensitivity, mainly consisting of algal dominated limestone pavement (with some low coral/sponge cover), sand/rubble veneered limestone pavement and sand flats (see Figure 2-7). These habitats are deemed to be of low sensitivity due to their widespread distribution in the greater region of the project.

As before, the pipeline will be trenched into the limestone pavement by excavator and then backfilled with rock armour. The intertidal portions of the groyne structure will become colonised by rock oysters, algae and crabs, whilst subtidal portions will be colonised by a range of sessile invertebrates. Hence, no long term loss of marine habitat is anticipated as a result.

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4.2 Construction of the Seawater Intake 4.2.1 Objectives and standards The objective for the operation of the seawater intake is to ensure it is not hazardous to marine fauna. 4.2.2 Potential impacts The plants proposed intake consists of a concrete caisson housing, screens and pumps and will be located approximately 800 m north of Cape Preston, on the eastern arm of the proposed harbour breakwater. Dual intake openings with nominal diameters of 2.5 m located on the west face of the pump station caisson will draw seawater from inside the harbour.

The operation of the seawater intake has the potential to be hazardous to marine fauna due to the intake current in the vicinity of the intake. 4.2.3 Management and mitigation The seawater intake system has been designed to minimise potential ingress of marine fauna as these have the potential to block screens and hinder the seawater filtration and desalination process.

The proposed intake openings will be located two metres above the seabed to protect against seabed silt entrainment and to provide adequate depth for pump suction.

The proposed intake to the desalination plant will be designed so not to act as a hazard to marine fauna. The intake flow velocity will be maintained below 0.33 m/s which will allow most species to swim against the drawn current if they approach the vicinity of the intake. Three sets of progressively finer screens will further reduce the possibility of intake of marine fauna. Firstly, bars with 100 mm spacing will cover the intake openings to prevent large marine fauna from entering the intake. Second will be bars with 20 mm spacing, followed by 5 mm mesh screens.

It is anticipated that at times there will be rafts of floating algae and perhaps blooms of jellyfish that will be trapped against the screens. This material will be cleaned off the screens and disposed of to landfill. 4.2.4 Alternative intake location There is the possibility that the proposed Cape Preston Harbour and breakwater may not be built by the time that the Balmoral South Project needs to construct the desalination plant. An alternative location is proposed (refer to Figure 2-7). Design features, intake flow velocity, sets of screens and the spacing of the bars will be same as for the proposed intake. 4.3 Operation of the Brine Discharge 4.3.1 Objectives and standards The objective for the desalination plant’s brine discharge is to maintain an adequate level of water quality in the waters surrounding Cape Preston, and to limit the area required for brine mixing surrounding the diffuser.

Site selection and diffuser design will ensure adequate mixing of saline brine is achieved within the designated mixing zone in order to achieve relevant water quality criteria for waters beyond the mixing zone.

Relevant guiding documents and standards include:

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• Department of Environment (2006). Pilbara coastal water quality consultation outcomes. Environmental Values and Environmental Quality Objectives. Marine Report Series Report No. 1. Perth WA.

• ANZECC & ARMCANZ (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Paper No. 4 Volume 1 The Guidelines. Canberra, Auckland.

• Ministerial Condition 635:8 for the Austeel Project at Cape Preston. 4.3.2 Description of brine discharge The desalination plant’s brine will contain concentrated dissolved solids (TDS) and concentrated suspended solids (TSS), as well as chemical additives used in the desalination process. The brine composition will remain constant over various flow rates. The maximum TDS discharged will be 78.8 g/L (see Appendix C) at a temperature no greater than 2°C above the temperature of the intake seawater. TSS concentration however will vary between 10 and 34 mg/L according to the ambient TSS range of 2 to 10 mg/L.

The brine outfall will be sized to enable a discharge of 252000 m3/day for short durations during ramp-up. The plant will usually operate producing brine of 157 000 m3/day. 4.3.3 Potential impacts of brine discharge The discharge of approximately 157 000 m3/day of saline brine has the potential to:

• reduce localised marine water and sediment quality

• adversely affect individual marine biota within the vicinity of the outfall

• reduce the abundance of sensitive benthic primary producer habit, including nearby coral communities

The most appropriate way to avoid the above impacts is to select a disposal site that does not currently support a high abundance of corals, seagrass or algae, ensure that sufficient depth of water is available at low tide for initial dilution to occur rapidly, and ensure that the waters above the outfall are well flushed and mixed. 4.3.4 Outfall site selection Extensive modelling of hydrodynamics in the vicinity of Cape Preston has been undertaken in order to find a suitable brine discharge location which was both technically feasible and adequate from a flushing perspective. Detailed information of modelling activities and results is provided in GEMS 2008 (see Appendix C).

Site selection investigations were based on three key elements in order to meet the proposal’s objectives. These being:

• that the brine discharge mixing zone be limited to an area of four hectares or less

• that sensitive habitats are protected from the operation of the outfall pipeline and diffuser, and

• that the diffuser and outfall pipeline can be adequately stabilised to protect against cyclone damage.

Site selection investigations identified that the outfall had to be located in at least 5 m depth of water at low tide to provide the initial dilution required to reduce the scale of the mixing zone. Three sites were investigated in relatively deep (5-10 m) water to the north and east of the Cape Preston port. All sites selected were located away from coral habitat and located over relatively barren sand-veneered limestone seafloor. The preferred site was chosen on the basis of achieving adequate brine dilution, being located a suitable distance away from sensitive benthic habitats, and being technically feasible to construct.

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Modelling was undertaken on the basis of a brine discharge rate of 252 000 m3/day. Noting that the plant will normally discharge brine at a rate of 157 000 m3/day, the modelling results can be interpreted as a very conservative estimate. 4.3.5 Brine dilution The objective is to limit the area required for brine dilution as much as is practicable. This will then ensure an adequate level of water quality is maintained for surrounding waters.

In order to achieve these objectives it was stipulated that the brine discharge mixing zone be limited to an area of no more than four hectares. More specifically, it was deemed that salinity variation resulting from the discharge of the plant should be no greater than 5% above the ambient level for more than one percent of the time anywhere around Cape Preston (except within the (4 ha) mixing zone) (MC635:8).

Modelling interpreted that the edge of the mixing zone was where salinity concentrations were 5% of ambient salinity. Given that ambient salinity at the site is between 35 and 40 ppt, this equates to approximately 2 ppt above background. Given that the brine discharge will have a concentration close to 80 ppt (78.8 mg/L), 40 dilutions are required to achieve acceptable mixing. Therefore, the objective of the modelling was to ensure the diffuser location would provide 40 dilutions within a 4 ha area for 99% of the time. 4.3.6 Brine modelling The dominant influence on the circulation in the waters off Cape Preston is the northwest shelf tides and the regional winds. Tides are relatively strong off Cape Preston with a typical semi-diurnal and spring-neap behaviour and a spring tidal range of 4.7 m. Water movements in the region during spring tides are more influenced by tidal currents than local wind conditions. Surface current velocities during spring tides can reach 0.75 m/s (1.5 knots) whereas during neap tides the peak current velocities are typically 0.25 m/s (0.5 knots).

There is no evidence of sustained stratification in the waters off Cape Preston from the 12 months of data recorded on site (GEMS 2008). The combination of relatively strong tidal currents, episodically strong winds producing wave action and surface currents and the relatively shallow bathymetry around Cape Preston tends to limit the opportunity for stratified layers to develop.

The dominant mixing and dispersion mechanism off Cape Preston is the strong and varying tidal currents and the episodic influence of strong surface winds.

The dominant flushing mechanism is the ebb tide which generally flows north-north-west from the site. The analysis of the Acoustic ADCP data (GEMS 2008) also highlights a relatively strong residual current to the north-east driven by the south-westerly winds and the ebb tide. 4.3.7 Modelling results The hydrodynamic model GCOM3D was run for a 12 month period using data collected at Cape Preston by GEMS during the period January to December 2007. This period has been determined by GEMS to represent a ‘normal’ year as far as seasonal wind strength and direction are concerned.

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In order to determine the cumulative effects of a second brine outfall discharge off Cape Preston, the GEMS PLUME3D model was used to determine the number of dilutions obtained and the maximum area of mixing zone required for 40 dilutions to occur for 100%, 99% and 95% of the time for both an assumed but yet to be built outfall for the Central Block Project outfall and for the proposed Balmoral South Project outfall (refer Figure 4-1).

Modelling results show that either outfalls could operate for 99% of the time within individual separate mixing zones each of 4 ha or less in area at the sites chosen for each outfall. Results also confirm that the mixing zone occurs locally to the diffuser and that the zone does not impact on coral habitats located in the vicinity of the outfall (refer Figure 2-7).

Note that the discharge of 252 MLD of brine has been modelled for each outfall and that the Central Block Projects outfall achieves the required number of dilutions within 3.9 ha, whilst the site proposed for the Balmoral South Project requires only 3.5 ha to achieve the same dilutions because it is approximately 3 m deeper than the CPMM outfall site (which is about 7 m deep).

As indicated previously, in the event that the Central Block Project port does not proceed at Cape Preston, the Central Block Project brine outfall will not be located where it is currently proposed. In this instance, the Balmoral South Project will construct an alternative outfall pipeline (as previously described) and the outfall diffuser will be located at the currently preferred Central Block Project site.

Figure 4-1 Percentage compliance of the two proposed brine discharges

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4.4 Brine Composition and Potential Effects The purpose of this section is to provide an overall assessment of the potential impacts of the brine effluent based on a review of available literature on known effects of desalination plants on marine ecosystems and assess the level of risk that the proposed effluents pose to the marine environment of Cape Preston. Prior to the assessment however, the desalination process is described and the characteristics of the brine are defined. 4.4.1 Desalination process and composition of brine effluent

Desalination Process A modular desalination plant based on reverse osmosis (RO) technology is proposed. The plant will contain three stages: pre-treatment filters, RO membranes, and post treatment chemical addition. The plant’s process equipment, such as filters, clarifiers and RO membranes, will be designed to operate at a product water rate of 40 GL/yr.

Pre-treatment In the desalination plant, seawater first passes through a pre-treatment section to remove suspended solids, which would otherwise clog the RO membranes. The plant must be reliable and produce water 365 days per year on a 24 hour a day basis. Significant raw water pre-treatment facilities are provided in order to treat the extremes of suspended solids levels anticipated. The pre-treatment process includes: flocculation, lamella sedimentation, direct air floatation and gravity dual media filtration. Flocculation and backwash discharges will be routed to the brine outfall for disposal as is common practice elsewhere in the world.

The pre-treatment process will involve the following steps:

• Injection of coagulant (Fe[SO4]3) and possibly sulfuric acid (H2S04) to the seawater feed.

— A coagulant (ferric sulphate) is added to incoming seawater to ensure optimal conditions for the coagulation process are reached. If required, sulphuric acid may be added to adjust the pH to the range required for ferric sulphate.

• Flocculation chambers for the seawater coagulation-flocculation process.

— Pre-treated seawater is injected with polymer as it enters two large flocculation chambers that are equipped with variable-speed mixers. The seawater is slowly mixed to achieve optimum flocculation and the formation of large flocs that can easily be removed.

• Lamella clarifier settlers for the removal of suspended matter with a specific gravity higher than the raw seawater.

— The flocculated seawater enters Lamella clarifier packs for the removal of larger suspended solid masses. While the water flows upward through the clarifier packs, the solids are settled out on the lamella plates, are removed by gravity feed, and then pumped into the brine system for discharge through the brine outfall. The seawater flows on for removal of fine particles in the DAF system.

• Dissolved air flotation (DAF) system for a gentle removal of suspended matter with low specific gravity, such as algae, plankton and other organic matter.

— The DAF system introduces microscopic bubbles of air through a system of air injection in a pressurised atmosphere to create saturated gas-saturated seawater. With the removal of pressure, microscopic air

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bubbles form that nucleate on fine suspended particles which then float upwards forming a surface foam that is mechanically removed, mixed with the RO brine and discharged through the brine outfall.

• Gravity dual media filters for the filtration of the remaining suspended matter.

— Clarified water from the DAF system is passed through a dual filter system consisting of in series filter beds (anthracite and then sand) with decreasing filter particle size. Backwash from these filters is mixed with the RO brine and discharged through the brine outfalls.

• Cartridge filters for final filtering to RO system.

— The DAF and bed-filtered seawater enters an array of cartridge filter vessels located in the reverse osmosis building for the final filtration process prior to the cleaned seawater being processed through the RO membranes. Cartridge filter elements are replaced approximately every 2 months.

RO membranes The reverse osmosis system removes dissolved solids from the seawater, producing clean permeate and a high salinity brine. The brine comprises 80 to 90% of the plants marine discharge.

A series of pumps and energy recovery devices deliver filtered high pressure seawater from the pre-treatment filter plant to racks of RO membranes. Here the seawater undergoes reverse osmotic separation to produce permeate (desalinated water) and brine (concentrated seawater). Fresh water permeates through the membranes at high pressure, passing through the energy recover devices, and is then discharged to the post treatment system and the product tank. The concentrated brine leaves the RO plant and is collected in a brine outfall tank, where it is mixed with the solids removed in the pre-treatment section and discharged through the ocean outfall pipelines.

Post treatment The permeate water leaving the RO plant is very low in alkaline mineral content and is therefore corrosive. The post treatment system adds lime (CaO) and carbon dioxide (CO2) to the water so that the water is neither aggressive nor calcium deficient and can be pumped to the processing equipment for use. Silicate impurities in the lime are removed and disposed of with the brine.

Discharge of chemicals used in the desalination plant

A number of chemicals will be required for efficient operation of the desalination plant. These are included in Table 4-1, along with their predicted dilutions at the end of pipe and in the marine environment. They include:

• Ferric sulphate for pre-treatment of intake water to maximise the sedimentation process. This reacts with bicarbonates in the seawater to form ferric hydroxide flocs which are removed during sedimentation along with seawater borne suspended solids and discharged with the brine.

• Sulphuric acid may be added when needed to adjust the seawater pH.

• Polymer (anionic polyacrylic): a flocculating chemical used in the seawater purification process and is removed from the system along with finer suspended solids during sedimentation and discharged with the brine.

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• Anti-scalant (mixed organic and inorganic chemicals such as Permatreat PC 191 or equivalent) will be continuously dosed into the RO feed line to prevent scale buildup. The anticalant is concentrated along with the seawater brine, but even so is discharged at very low levels.

• If hypochlorite is used as a biocide, sodium metabisulphite will be added to the discharge to destroy residual chlorine. Both these chemicals are neutralized in the system resulting in no residual discharge

Both anti-scalant and polymer are developed to have negligible biological toxicity because, typically, RO systems are designed to supply domestic needs in most cases. Material Safety Data Sheets, which include toxicity information showing that the material is non-toxic, are provided in Appendix D.

Table 4-1 Chemicals used in the RO process and dilutions in the marine environment

Mixing-zone Dosing Discharge boundary Dosing chemical Purpose concentration Concentration ppm Concentration ppm ppm NaOCl Intake 5 nil nil intermittent

Acid H2S04 Pre-treatment 29 nil nil Continuous

Ferric Sulphate Fe2(SO4)2 Pre-treatment 12 8.0 – discharged 0.3 Continuous as Ferrous 0.2 Hydroxide Polymer (anionic Flocculant 0.3 0.5 Nil polyacrilic such as Nalco Continuous 8103 Plus or equivalent) SBS (Sodium Bisulphite) Pre-treat 10 nil nil intermittent Anti-scalant (such as RO Continuous 1.5 2.2 0.05 Permatreat PC191 or equivalent)

Lime Post-treatment 46 2 – discharges 0.05 Continuous silicate impurities

4.4.2 Impact assessment Whilst desalination plants are a relatively recent introduction to Western Australia, they have been operating elsewhere in the world for over 20 years. At the beginning of 2006, more than 12,000 desalination plants were in operation throughout the world, producing about 40 million cubic meters of water per day. Slightly over 1% of this capacity is produced in Australia (WHO 2007).

Despite the vast amount of desalination plants operating around the world, there are many knowledge gaps and uncertainties regarding the impacts of desalination projects on the environment, as monitoring results of operating plants are only available to a limited extent (WHO 2007). It is however known that impacts are possible from operation of a Reverse Osmosis (RO) desalination plant associated with the discharge of the brine into the sea (Münk 2008), and with residual chemicals from pre and post-treatment processes (Lattemann

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2007), particularly where flushing of the receiving waters is not high. Such potential impacts can arise either from the salinity, density and pH of the brine, or from additives to the brine such as oxygen scavengers, antiscalant compounds, biocides such as chlorine used to inhibit biofouling, coagulants, or from metals leached from internal pipeworks.

Table 4-2 below (modified after Lattemann 2008) provides an overview of potential sources of operational impacts normally associated with RO plants and whether or not they are applicable to the proposed Balmoral South Project plant at Cape Preston.

Table 4-2 Possible source of operational impacts of RO plants and applicability to the proposed Balmoral South Project plant

Source of potential Associated concern Relevance to IM Plant impact

Brine typically has a concentration of ~ Brine will be ~80 ppt. However flushing 80ppt . Where effluent at this concentration and mixing at the outfall site is high and Salinity and density of accumulates on the seafloor for any length unlikely to enable accumulation of high brine of time, it can cause localised mortality of brine concentrations over seafloor for certain marine organisms any appreciable length of time De-aeration and Receiving waters are saturated in application of oxygen oxygen and the effluent will be re- scavengers to intake Can cause reduced oxygen concentration in oxygenated very soon after discharge. waters Brine

If hypochlorite is used as a biocide, Use of chlorine for sodium metabisulphite will be added to biofouling control in intake Use of hypochlorite can result in residual the discharge to destroy residual waters chlorine being discharged with the brine chlorine. Both these chemicals are neutralized in the system resulting in no residual discharge Balmoral South Project plant will use modern compounds that have been Some early antiscalants and flocculants demonstrated to be non-toxic as follows: Addition of antiscalant and were potentially toxic to marine organisms. - Antiscalent : PermaTreat® PC-191 a flocculant to intake waters Modern compounds have now been phosphonate: developed to be non-toxic. - Flocculant: Polymer (anionic polyacrylic).

Ferric sulphate (Fe2(SO4)2 for pre-treatment This will occur in mixing zone of intake water to maximise the Coagulants and coagulant sedimentation process. This reacts with aids bicarbonates in the seawater to form ferric hydroxide flocs. Can colour effluent with orange stain Brine will be treated before discharge to pH Lowered pH can affect marine biota raise pH The seawater-contact surfaces for the Plants discharge metals from pipework desalination plant will be either concrete, installed for the desalination process, PVC, fibreglass or high grade stainless Heavy metals thereby leading to elevated metals in steel. There will therefore be no receiving waters and sediments around the discharge of trace metals for the outfall. proposed Balmoral South Project plant blowdown.

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Further detail on each of the potential sources of impact outlined in Table 4-2 above is presented in the following pages.

Salinity and density The salinity of desalination effluent depends on the recovery rate (= freshwater volume/feed water volume) of the plant. The higher the recovery rate, the less brine volume generated, but the higher the salinity (Lattemann & Höpner 2008). The recovery rate for the proposed plant lies at approximately 50%, resulting in a brine discharge salinity of approximately 80 ppt (ambient salinity varies between 35 and 40 ppt).

Effect of high salinity on marine organisms Typically, the range of natural salinity fluctuation is at least +/- 10% of the average annual ambient seawater concentration. The actual salinity tolerance of most marine organisms is usually significantly higher than this level (WHO 2007). However, there are limited documented studies or experiments on the impacts of salinity fluctuation on marine organisms (e.g. Danoun 2007; Münk 2008; Del Pilar Ruso et al. 2007; Latteman & Hőpner 2003) and the outcome of studies undertaken vary according to the environment and the organisms examined.

A study, undertaken off the coast of Blanes in Spain (NW Mediterranean) examined the possible effects of discharges from a desalination plant on the macrobenthic community inhabiting sandy substratum. The results showed that no significant variations within the benthic community could be attributed to the brine discharges (Raventos et al. 2006). On the other hand, an investigation of the possible effect of brine discharge on the benthic infauna undertaken in Southwest Spain (Alicante coast) showed that the diversity of the benthic community changed significantly. However, these results were only recorded at sites in close proximity (approx. 100-150 m) to the diffuser, and not at sites further away from the diffuser (approx. 400 m). It was also observed that echinoderms nearly disappeared in close proximity of the diffuser (Del Pilar et al. 2007).

Corals, like other invertebrates, have no mechanisms of osmoregulation (Muthiga & Szmant 1987), which is the regulation of keeping the body's fluids from becoming too diluted or too concentrated. Therefore, a change in salinity may affect corals’ metabolism and survival (Muthiga & Szmant 1987; Coles 1992).

The effects of increased salinity on corals have not been thoroughly studied because it is considered that most coral reefs occur in waters with a relatively stable salinity. However, investigations that have been done reported different outcomes, depending on the species examined. For example, the common hard coral Stylophora pistillata is sensitive to small increases in salinity (Ferrier-Page et al.1999). Small colonies of S. pistillata died following three weeks of an exposure to higher salinity values of approx. 2 ppt. Muthiga and Szmant (1987) subjected colonies of the hard coral Siderastrea siderea to both long-term and sudden decreases and increases in salinity. They reported that S. siderea was able to withstand sudden and prolonged changes in salinity without measurable whole-colony effects. All studies showed that the effects associated with increased salinity could only be detected in close proximity of the outfall and/or under laboratory conditions.

Even less information is available on the effect of increased salinity on plants. However, it appears that sensitivity to salinity changes are species specific, no matter which type of organism it is. Perez-Talavera and Questa-Ruiz (2001) examined the effects on Cymodocea nodosa (seagrass) and Caulerpa polifera (alga) meadows off the Canary Islands and did not observe any impact. On the other hand, a study undertaken in the Western Mediterranean found lower growth and higher mortality rates for Posidonia oceanica (seagrass) at salinity levels above app. 39 ppt (Buceta et al. 2003).

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Information on mobile organisms, such as fish, is also sparse and the outcomes depend on the species and the environment examined. Perez (1969) for example states that certain fish species are not sensitive to salinity change. Others (Miri & Chouikhi 2005) consider that particular species leave an area when salinity increases.

In summary, it appears that sensitivity to marine organisms associated with salinity fluctuation depends on a variety of factors, including the environmental setting, range of salinity fluctuation and the organisms itself. As previously stated, the objective is to ensure that the salinity increase outside the mixing zone is no greater than 5% (which =~2 ppt) above the ambient salinity for more than one percent of the time anywhere around Cape Preston. Hence if any impacts occur, they will be restricted to within the mixing zone and the brine effluent will pose no risk to the broader marine environment outside this zone.

Of interest is the fact that echinoderms (starfish, urchins, etc.) are osmo-regulators, and are known to be sensitive to salinity changes (Fernandez-Torquemada et al. 2005; Del Pilar et al. 2007). They are abundant in the Cape Preston area, and they are relatively easy to identify in situ, and as such may make a good sentinel organism for monitoring the actual effect of the brine discharge on seafloor communities.

Density The density difference between brine and seawater can induce the formation of a stratified system, with the brine forming a bottom layer that can affect the benthic communities which are used to stable salinity environments (Lattemann & Hőpner 2003). The above described negative effects to salinity variation might be intensified in a stratified water body.

However, as described in Section 2, the receiving waters of Cape Preston are highly energetic and no evidence of stratification has been found in over 12 months of ADCP monitoring at Cape Preston. Given the 4.75 m range of the semi-diurnal tides in the area, it is considered most unlikely that stratification will develop at either of the proposed outfall sites. Diffuser design and location have been subject to extensive modelling to ensure adequate dispersion of brine within the designated 4 ha mixing zone during the most challenging worst–case dispersion conditions, this being slack water during low neap and spring tides (GEMS 2008).

Antiscalant The antiscalant product proposed to be used for the IM plant (PermaTreat® PC-191) is a phosphonate which, despite being effective against scaling, it is also claimed to inhibit corrosion (Falbe & Regitz 1995). The proposed desalination plant will dose 1.5 ppm antiscalant which is similar to the concentration (1.4 ppm) used for a research plant in Doha (Al-Shammiri et al. 2000). The estimated concentration at discharge will be 2.2 ppm and at the mixing zone boundary, approximately 0.05 ppm.

A variety of toxicological and ecotoxicological tests have been undertaken for this product (see Material Safety Data Sheets, Appendix D), using fish species such as rainbow trout, sheepshead minnow, bluegill sunfish, channel catfish, invertebrates including Daphnia magna and the grass shrimp and the green algae Selenastrum capricornutum. All tests showed that the product is non-toxic. Furthermore, ecotoxicological test have been undertaken for the desalination plant in Cockburn Sound. The Whole of Effluent Toxicity Testing (WET) was performed on a suite of bioassays using marine species representative of the receiving ecosystem in Cockburn Sound, as recommended by the ANZECC and ARMCANZ (2000) water quality guidelines. Testing consisted of sublethal short-term tests with endpoints such as growth (microalga, fish larvae), larval development (mussel), reproduction (copepod) and germination (macroalga).

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The results of these tests were used to plot a species sensitivity distribution to calculate a concentration of brine that will protect 80% of the exposed species to a maximum of 10% impact at the edge of the mixing zone. No toxicological effects have been found (Woodworth 2008)

Furthermore, Hőpner and Lattemann (2002) who investigated the chemical impacts from seawater desalination plants in the northern Red Sea, identified that the LC 50 values for antiscalants are relatively high, indicating a low toxicity.

In summary, no evidence of any toxic effects of the antiscalant could be found in the literature, nor could any toxic effect be identified from toxicological tests undertaken for the Material Safety Data sheets and for the desalination plant in Cockburn Sound.

Coagulant and flocculant Flocculant

The flocculant, an anionic polyacrylic NALCO 8103 Plus is used in the seawater purification process. The proposed desalination plant will dose 0.3 ppm of the polymer NALCO, the estimated concentration at discharge will be 0.5 and at the mixing zone boundary discharge will be nil. A variety of toxicological test have been undertaken using rats and rabbits. Furthermore, ecotoxicological tests have been done using rainbow trout and inland silverside. Invertebrates used for acute testing included Daphnia magna and Ceriodaphnia dubia and chronic tests were done with Ceriodaphnia dubia. The flocculant to be used contains no organic halogens.

A similar product to the above has also been used by Butt et al. (1997) and according to Lattemann and Hopner (2003) is non-toxic at levels applied in RO plants.

Coagulant and TSS

TSS concentration on discharge is estimated to vary between 10 and 34 mg/L under normal ambient conditions of 2-10 mg/L.

The coagulant (ferric sulphate) will be added to incoming seawater to ensure optimal conditions for the coagulation process is reached. This reacts with bicarbonates in the seawater to form ferric hydroxide flocs which are removed during sedimentation along with seawater borne suspended solids and discharged with the brine. If required, sulphuric acid may be added to adjust the pH to the range required for ferric sulphate. The proposed desalination plant will dose 12 ppm ferric sulphate. The estimated concentration at discharge will be 8.0 ppm and at the mixing zone boundary after receiving 40 dilutions will be approximately 0.2 ppm.

Ferric hydroxide forms a precipitate, is reddish brown in colour and might cause a discoloration of seawater as well as a decrease in light penetration (Lattemann & Hőpner 2003).

Therefore, the brine discharge will be turbid and coloured. Turbidity near the outlets might impair photosynthesis and if the suspended solids settled out, may cause sedimentation of benthos.

Substantial literature is available on the effect of turbidity and sedimentation on corals (Fabricius 2005 and references therein), including reduced coral cover (Brown et al. 1990), reduced recruit survival, (Fabricius et al. 2003) reduced fertilisation (Gilmour 1999) and changed coral community (West & Van Woesik 2001). In general, suspended solids, turbidity and sedimentation are potential sources of degradation to scleractinian coral assemblages (Rogers 1990), and can impact corals at all stages of their development (gametes to adult colonies).

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Sedimentation, TSS and turbidity are natural agents of coral disturbance. Levels of these variables vary naturally in space and time in response to environmental conditions (Larcombe et al. 1995). Storm generated waves and flooding are processes that increase levels of these variables, usually over short temporal scales (days to weeks), but over large spatial scales (e.g. >100 km from source). Corals have adapted to thrive in locations experiencing naturally high turbid conditions, such as those off Cape Preston and Dampier.

Field surveys and benthic habitat mapping conducted in the proposal area identified low coral cover (URS 2007). Most of the habitats in the shallows adjacent to Cape Preston are relatively barren intertidal sand flats or shallow algae dominated pavements. Any possible impact on the sparse corals and the algal pavement will be minimised if the solids are discharged continuously into well mixed water (Lattemann & Hőpner 2003), which is the situation which occurs at the proposed outfall site.

Coagulant and visibility

A study undertaken in the mid seventies on a trial disposal of iron rich effluent into the sea off Bunbury WA, from the Laporte titanium factory at Australind (Murphy 1981) suggested that a reasonable limit of visual detection of a ferric plume is probably 0.1 mg/L ferric directly at the outfall location, which will become invisible a short distance from the outfall. Given this finding, it is anticipated that the ferric stain will only be visible within the mixing zone which has been located away from sensitive benthic habitats.

In summary, the possible effect of the coagulant on the environment (visibility of plume, TSS and precipitate) is minimised by the diffuser design and location, which has been subject to extensive modelling to ensure adequate dispersion of brine within the designated 4 ha mixing zone during the most challenging circumstance, this being slack water during low neap and spring tides (GEMS 2008). Risk of any impacts on the entire ecosystem in the proposed area is classified as low, as the ecosystem falls in the category of ‘non-sensitive’ (see below). 4.4.3 Overall effects on the ecosystem Höpner et al. (1996) presented a list which ranks 15 coastal sub-ecosystems according to their sensitivity to brine discharge (Table 4-3). Criteria for his classification included the sensitivity towards desalination effluent characteristics, the water exchange capacity of the outfall location and the natural recovery potential of the receiving environment. The greater the number of the ecosystem (Rank Nr) the more sensitive it is and the more adverse effects can be expected from brine discharges. Conversely low rankings indicate low sensitivity.

The characteristics of the marine ecosystem around Cape Preston are those that are described for the lowest rankings of 1-3. Given the low sensitivity of the outfall site, the excellent flushing provided by semi-diurnal macro-tides, the low sensitivity of the receiving environment in the vicinity of the outfall, and the negligible toxicity of the effluent components, the likelihood of any adverse effects arising from the brine discharge on the marine environment outside the mixing zone is considered extremely low. Similarly, the risk of causing long- term environmental harm to the receiving waters inside the mixing zone is also considered extremely low.

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Figure 4-2 Example of macro-tidal range over neap tides (11 to 17 May 2008) and spring tides (18 to 24 May 2008)

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Table 4-3 Coastal sub-ecosystems and characteristics ranked according to their sensitivity (based on Höpner & Windelberg 1996, in Münk 2008)

Rank Ecosystem Characteristics Characteristics No. High energy oceanic coast rocky or plenty of oxygen, nutrients and energy; 1 sandy, with coast parallel currents efficient biodegradation 2 Exposed rocky coasts good water exchange in all areas low particle accumulation through high 3 Mature shorelines sediment mobility 4 Coastal upwelling high water exchange, but seasonally limited still high sediment mobility, but accumulation 5 High energy soft tidal coast tendency in certain areas Estuaries and estuary-similar seasonally changing water quality and 6 systems turbidity Low energy sand-, mud- and limited water exchange; house many species 7 beachrock-flats and tend to accumulation exposed to wind, dust and solar radiation; 8 Coastal sabkahs rarely capable of degradation shelter for many sea animals; limited 9 Fjords exchange and tendency to oxygen deficits Shallow low-energy bays and semi- endangered by load concentrations; low 10 enclosed lagoons water exchange lower sensitivity, but reactions to many stress 11 Algal (cyanobacterial) mats factors are still unknown sanctuary for breeding animals; tendency to 12 Seaweed bays and shallows load concentration; sensitive shelter for a big variety of species; many 13 Coral reefs species with high sensitivity sensitive macrophytes and animals; very 14 Saltmarsh vulnerable to load concentrations rapid decline through pollution and changing 15 Mangrove flats conditions; plants and animals can hardly tolerate any pollution

4.5 Seawater Return Outfall 4.5.1 Objectives and standards The objective for the operation of the seawater return outfall is to:

• ensure an adequate level of water quality is maintained in the Cape Preston area.

• ensure its construction and operation does not cause significant erosion or impact to nearby benthic habitats.

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4.5.2 Potential impacts and their mitigation In breakdown and start-up situations, the pre-treatment filters of the desalination plant may overflow, discharging the full feed stream of raw seawater for short periods. A seawater return outfall pipeline located adjacent to and just north of the desalination plant will return this untreated seawater to the ocean.

The overflow outfall will discharge up to 3.62 m3/s of filtered, untreated seawater for periods up to 30 minutes duration. The salinity, temperature, and ionic composition of the seawater will be the same as the ambient waters but may also include dosing from the coagulant and flocculation process (ferric sulphate or polymer). Such short infrequent discharges are most unlikely to affect water quality even locally.

However, the high volume discharge resulting from operation of the seawater return outfall has the potential to cause localised erosion to nearby benthic habitats when it is operational, unless the outfall is appropriately located. To mitigate against this, the overflow outfall will be constructed to discharge onto the intertidal rock pavement which fringes the coast of Cape Preston, onto an area primarily dominated by algal covered limestone pavement with oyster encrusted basalt rocks (see Figure 2-7).

It is anticipated that this infrequent discharge of short duration onto rock platform will not cause erosion. Furthermore, there is unlikely to be any significant change in abundance and distribution of algae and oysters locally as these species are hardy and will rapidly recolonise any bare substrate. 4.5.3 Interactions and cumulative impacts of brine discharges The proposed Balmoral South Project brine discharge will be located to the north west of the proposed brine outlet and diffuser of the Central Block Project. To assess whether there would be any detrimental interactions or cumulative impacts from both discharges if approved and operational, modelling was undertaken for both desalination plant discharges operating simultaneously.

Modelling was undertaken on the conservative basis of a brine discharge rate of 252 000 m3/day from each outlet. If approved each outlet will only normally discharge brine at a rate of 157 000 m3/day.

Modelling concluded that each diffuser will achieve 40 dilutions within a 4 ha mixing zone for 99% of the time. This would ensure that salinity as a result of each discharge is no greater than 5% above the ambient level for more than one percent of the time anywhere around Cape Preston (except within the two (4 ha) mixing zones around each diffuser).

Figure 4-1 highlights that both discharge diffusers will essentially operate independently of each other and for 99% of the time brine will be mixed to the required dilutions within each individual 4 ha mixing zone. Interactions between brine discharged from each diffuser are therefore deemed to be negligible and it is believed that there will be no cumulative risk from both discharges operating simultaneously.

4.6 Effect of Brine Outfall Construction and Operation on EPBC Listed Species Sea turtles are listed as Threatened and Migratory Species under the EPBC Act 1999, and dugong are listed as Migratory Species. Both Threatened Species and Migratory Species are matters of National Environmental Significance (NES) under the EPBC Act. As indicated in section 2.9 both turtles and dugong are known to occur in nearshore waters between Dampier and Exmouth, and small numbers of turtles are believed to nest on the beaches on the west side of Cape Preston. The size of the dugong population in this region is not reliably

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Section 4 Potential Impacts and their Mitigation known, but sightings of single dugong have been made by field survey teams in the region on more than one occasion.

As previously described the outfall pipeline trench will be constructed by barge mounted backhoe excavator into which a pipeline will be laid and the trench will subsequently be backfilled with rock. The whole task is anticipated to take between one and two months depending on the weather. The outfall diffuser will be 150 m long and will be surrounded by a mixing zone of 4 ha in area into which hypersaline water (~80 ppt) will be discharged.

It needs to be remembered that by the time the Balmoral South Project outfall is constructed, the Central Block Project port will be in operation at Cape Preston, exporting magnetite concentrates and pellets with frequent movements of tugs. Hence by the time the outfall of the Balmoral South Project is constructed and operational, dugong and turtle abundance locally may have already declined as a consequence of an avoidance reaction to the additional disturbance in the region.

Irrespective of background disturbance, the scale of disturbance from just the construction of the outfall is small, temporary and short term. The scale of disturbance from the operation of the outfall is permanent but small (4 ha) and localised.

Significant impact guidelines are available which provide criteria for use in determining if a proposed action will have a significant impact on a matter of NES. The criteria for listed migratory species are reproduced in the box below from the EPBC Act policy Statement 1.1 (May 2006)

Significant impact criteria for Listed Migratory Species An action is likely to have a significant impact on a migratory species if there is a real chance or possibility that it will: • substantially modify (including by fragmenting, altering fire regimes, altering nutrient cycles or altering hydrological cycles), destroy or isolate an area of important habitat for a migratory species; • result in an invasive species that is harmful to the migratory species becoming established in an area of important habitat for the migratory species; or • seriously disrupt the lifecycle (breeding, feeding, migration or resting behaviour) of an ecologically significant proportion of the population of a migratory species.

¾ What is important habitat for a migratory species? An area of ‘important habitat’ for a migratory species is: a) habitat utilised by a migratory species occasionally or periodically within a region that supports an ecologically significant proportion of the population of the species; and/or b) habitat that is of critical importance to the species at particular life-cycle stages; and/or c) habitat utilised by a migratory species which is at the limit of the species range; and/or d) habitat within an area where the species is declining.

¾ What is an ecologically significant proportion? Listed migratory species cover a broad range of species with different life cycles and population sizes. Therefore, what is an ‘ecologically significant proportion’ of the population varies with the species (each circumstance will need to be evaluated). Some factors that should be considered include the species’ population status, genetic distinctiveness and species specific behavioural patterns (for example, site fidelity and dispersal rates).

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¾ What is the population of a migratory species? ‘Population’, in relation to migratory species, means the entire population or any geographically separate part of the population of any species or lower taxon of wild animals, a significant proportion of whose members cyclically and predictably cross one or more national jurisdictional boundaries including Australia.

It is considered highly unlikely that the habitat that will be disturbed by construction and operation of the outfall is ‘important habitat for a migratory species’. The location is mobile sand veneered limestone pavement which supports little to no seagrass. Habitat mapping undertaken by URS (2007) indicates that Halophila sp. seagrass patches have been recorded in the shallow sand habitat on the western side of SW Regnard Island as well as in the lee of Fortescue Island. Sparse seagrasses also occur on the shallows to the west of Cape Preston. Surprisingly, the areas which support the densest and largest patches of Halophila seagrass occur in the deep water basin (>15 m) which is located some 8-10 km to the north of Cape Preston.

It is also considered most unlikely that construction and operation of the outfall will result in an invasive species that is harmful to the migratory species becoming established. The construction Environmental Management Plan (EMP) for the outfall will have to comply with the Central Block Project Port EMP which includes a Biofouling and Ballast Water Management Plan. Implementation of this plan will ensure that the risk of marine pest introductions from any vessels or barges brought to the site for construction purposes is assessed and corrective actions are undertaken if considered necessary.

It is also considered most unlikely that the construction and operation of the outfall will seriously disrupt the lifecycle of an ecologically significant proportion of the population of either dugong or turtles. By the time the outfall is built, there will already be a port in operation at Cape Preston and it is likely that the effects of this background disturbance will outweigh the effects of the outfall. The little data that are available on turtle and dugong populations in the region certainly do not indicate that an ecologically significant proportion of the populations relies on habitats in the immediate vicinity of Cape Preston.

It is therefore considered that construction and operation of an additional brine outfall at Cape Preston poses little to no risk to populations of migratory species of dugong and turtles in the region.

Significant impact guidelines are also available which provide criteria for use in determining if a proposed action will have a significant impact on a threatened species. These criteria are reproduced in the box below from the EPBC Act policy Statement 1.1 (May 2006).

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Significant impact criteria for Listed Threatened Species An action is likely to have a significant impact on a critically endangered or endangered species if there is a real chance or possibility that it will: • lead to a long-term decrease in the size of a population; • reduce the area of occupancy of the species; • fragment an existing population into two or more populations; • adversely affect habitat critical to the survival of a species; • disrupt the breeding cycle of a population; • modify, destroy, remove, isolate or decrease the availability or quality of habitat to the extent that the species is likely to decline; • result in invasive species that are harmful to a critically endangered or endangered species becoming established in the endangered or critically endangered species’ habitat; • introduce disease that may cause the species to decline; or • interfere with the recovery of the species.

¾ What is a population of a species? A ‘population of a species’ is defined under the EPBC Act as an occurrence of the species in a particular area. In relation to critically endangered, endangered or vulnerable threatened species, occurrences include but are not limited to: • a geographically distinct regional population, or collection of local populations; or • a population, or collection of local populations, that occurs within a particular bioregion.

¾ What is an invasive species? An ‘invasive species’ is an introduced species, including an introduced (translocated) native species, which out- competes native species for space and resources or which is a predator of native species. Introducing an invasive species into an area may result in that species becoming established. An invasive species may harm listed threatened species or ecological communities by direct competition, modification of habitat or predation.

¾ What is habitat critical to the survival of a species or ecological community? ‘Habitat critical to the survival of a species or ecological community’ refers to areas that are necessary: • for activities such as foraging, breeding, roosting, or dispersal; • for the long-term maintenance of the species or ecological community (including the maintenance of species essential to the survival of the species or ecological community, such as pollinators); • to maintain genetic diversity and long term evolutionary development; or • for the reintroduction of populations or recovery of the species or ecological community. Such habitat may be, but is not limited to: habitat identified in a recovery plan for the species or ecological community as habitat critical for that species or ecological community; and/or habitat listed on the Register of Critical Habitat maintained by the Minister under the EPBC Act.

On the basis of the above criteria and preceding discussion, it is considered highly unlikely that construction and operation of an additional brine outfall at Cape Preston will have a significant impact on the regional population of sea turtles, particularly given that much more important breeding and nesting areas occur in the Montebello Islands, which occur 70 km to the west of Cape Preston, and in the islands of the Dampier Archipelago, which occur about 50 km to the east of Cape Preston. In addition, operation of the outfall will not affect the beaches to the west of Cape Preston where small numbers of turtles are believed to occasionally nest.

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Hence it is considered that construction and operation of an additional brine outfall at Cape Preston will not have a significant impact on either dugong or turtle populations in the region surrounding Cape Preston. 4.6.1 Other marine species The humpback whale, listed as vulnerable under the EPBC Act, migrates along the Western Australian coast in winter and early spring. Along parts of the migratory route there are narrow corridors and bottlenecks resulting from physical and other barriers where the majority of the population passes close to shore (i.e. within 30 km of the coastline). These habitat areas are important during the time of migration and in Western Australia include areas around Geraldton/Abrolhos Islands, and Point Cloats to North West Cape. Calving takes place in the Southern Kimberley between Broome and the northern end of Camden Sound and there are resting areas located around Exmouth Gulf, Shark Bay and Geographe Bay (Department of Environment and Heritage 2005). The whales are not known to aggregate in the waters offshore Cape Preston, but it is possible that individuals, as well as small pods of dolphins, pass through the area. The impacts of construction and operation of an additional brine outfall at Cape Preston on these species is considered little to no risk.

It further should be noted that seasnakes have been observed to occur in the proposed area. Wells and Walker (2003) reported the occurrence of the following six species in the Dampier Archipelago: Aipysurus laevis, Astrotia stokesii, Ephalophis greyi, Hydrelaps darwiniensis, Hydrophis sp. and Fordonia leucobalia. The impacts of construction and operation of an additional brine outfall is considered to pose a very low risk to these species.

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Water Quality Management Framework Section 5

5 Water Quality Management Framework 5.1 Water Quality Management Framework The preparation and application of a Water Quality Management Framework (WQMF) will be the key tool in achieving the objectives of the proposal. It will be developed to ensure that an adequate level of water quality within the Cape Preston region is maintained as a result of the brine discharge.

The WQMF will include:

• Establishing EQOs for uses and values and where they will be protected

• Establishing appropriate EQC required to sustain each EQO

• Providing a high level of ecological protection to waters in the region of Cape Preston, except for the mixing zone surrounding the brine discharge and the moderate protection zone within the proposed port and surrounding operational areas.

The basic elements of this WQMF are presented below. 5.1.1 Environmental values and quality objectives The EPA has endorsed a set of overarching EVs and EQOs applicable to Pilbara coastal waters. Detailed information of this process is provided in section 3.

Recognising the significant amount of work and consultation undertaken to develop these EVs and EQOs, they are deemed to be relevant for application to the proposal area, and as such will be applied to the WQMF, as outlined in Figure 5-1. 5.1.2 Application of EVs, EQOs and EQC to the Cape Preston area EVs and EQOs have been applied in order to maintain an adequate level of water quality in waters surrounding the Port. Figure 5-2 delineates the levels of ecological protection and where they apply for the waters of the proposal area and the broader Cape Preston region. The levels of protection and application are also discussed briefly below.

Ecological Value A high level of ecological protection will apply to all waters of Cape Preston outside of the brine mixing zone and the port operational area. This will ensure adequate water quality in the surrounding port waters and that the maximum level of ecological protection applied by the EPA is maintained for waters east of Cape Preston, in the vicinity of SW Regnard Island.

A moderate level of ecological protection will be applied to all surrounding waters, excluding the 4 ha mixing zone around the desalination plant’s brine discharge, where a low level of ecological protection is applied. The application of a moderate protection area to the port waters is consistent with protection levels applied by the EPA to other operational ports and wharfs in the Pilbara region.

Social Use Values Consistent with the EPA’s objectives, social use values apply to all waters of the port area and the broader Cape Preston area.

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Section 5 Water Quality Management Framework

Environmental Quality Criteria In the interim, Environmental Quality Criteria (EQC) applicable to the CPWQMF will be those published in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC & ARMCANZ 2000).

Reference is also made to the EQC Reference Document for Cockburn Sound (2003-2004) (EPA 2005). Table 5-1 outlines the EVs, EQOs and interim EQC to be applied to the proposal area and the broader Cape Preston region.

As the WQMF and associated monitoring programs become established, locally specific EQC may be developed in consultation with the DEC. These EQC will be derived from suitable reference sites according to the recommended approach in ANZECC and ARMCANZ (2000) (i.e. 20th and/or 80th percentiles of reference distribution for high ecological protection and 5th and/or 95th percentiles for moderate ecological protection).

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Table 5-1 Interim EVs, EQOs and EQC for Cape Preston Waters

Environmental EQO Level of Where Protected Interim EQC (as per: ANZECC & ARMCANZ 2000) Environmental Quality Objective Value No. Protection Physical and Chemical Stressors – not to deviate beyond the 5th and 95th percentile of reference distribution. All waters outside port Salinity – Not to exceed 5% of ambient for 1% of the time High operational area Toxicants in Water – Table 3.4.1* (99% species protection) Toxicants in Sediment – Table 3.5.1* Maintenance of ecosystem integrity This means maintaining the structure (e.g. the variety and quantity Physical and Chemical Stressors – not to deviate beyond the 20th and 80th percentile of reference distribution Ecosystem Health EQO 1 of life forms) and function biodiversity, biomass and abundance of Port and harbour biota) and functions (e.g. the food chains and nutrient cycles) of operational area (excluding Salinity – Not to exceed 5% of ambient for 1% of the time Moderate marine ecosystems. Three levels of ecological protection shall brine discharge mixing Toxicants in Water – Table 3.4.1* (not to exceed 95% apply to Cape Preston: High, Moderate, and Low. zone) species protection for more than 5% of the time) Toxicants in Sediment – Table 3.5.1* Toxicants in Water – Table 3.4.1* (not to exceed 90% 4ha desalination brine species protection for more than 5% of the time) Low discharge mixing zones Toxicants in Sediment – only for substances that adversely bioaccumulate/biomagnify Water quality is safe for recreational activities in the water EQO 2 Table 5.2.2* (e.g. swimming)

Recreation & Water quality is safe for recreational activities on the water EQO 3 Table 5.2.2* Aesthetics (e.g. boating)

EQO 4 Aesthetic values of the marine environment are protected. Table 5.2.2*

Cultural and Cultural and Spiritual values of the marine environment are Maintenance of other EQOs should provide adequate level EQO 5 Spiritual protected N/A All waters of protection for EQO5 Table 4.4.4*, Table 4.4.5* & Table 9.4.46*. Refer EPA EQO 6 Seafood (caught or grown) is of a quality safe for eating 2005, Table 4^ for metals in Seafood. Fishing & Aquaculture EQO 7 Water quality is suitable for aquaculture purposes Table 4.4.2* & Table 4.4.3*

Industrial Water Maintenance of other EQOs should provide adequate level EQO 8 Water quality is suitable for industrial supply purposes Supply of protection for EQO 8

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Section 5 Water Quality Management Framework

Figure 5-1 Proposed ecological protection areas for the proposal area

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Water Quality Management Framework Section 5

5.2 Monitoring and Reporting A monitoring program will be implemented as part of the WQMF. The established EQC will be the benchmarks against which the level of achievement of the EQOs are measured. If EQCs are being met it will be deemed that the EQOs, and by extension the EVs, are being maintained.

If monitoring identifies a breach of an established EQC further investigations will be undertaken to assess the status of the relevant EQO. If investigations determine that an EQO is not being met, then an appropriate management response will be implemented. 5.2.1 Diffuser performance monitoring Once fully operational, a routine monitoring program for salinity will be completed around the brine discharge diffusers. This monitoring will be undertaken to validate the modelling results and ensure that the adequate level of dilutions is being achieved within the 4 ha mixing zone, and that the salinity criteria are being met at the boundary of the mixing zone and the moderate ecological protection area. 5.2.2 Wastewater stream monitoring

Physical Parameters In-line sampling is to be installed within the desalination plant intake and outfall to directly measure:

• pH

• temperature

• salinity

These data will be used to ensure ongoing compliance with mixing zone requirements, following the completion of the diffuser performance monitoring.

Toxicants As the seawater contact surfaces will be either concrete, PVC, fibreglass or high grade stainless steel there will be no leaching of trace metals into the brine discharge stream. However, the process of concentrating seawater will lead to increases in concentrations of dissolved metals and metalloids.

An automated system will be installed for withdrawing and maintaining samples from both the desalination intake and discharge for later analysis of toxicants including metals, metalloids and desalination chemicals.

Toxicants to be measured include those likely to be:

• Found in local waters; e.g. metals and metalloids concentrated due to the removal of fresh water in the desalination plant.

• Dosing chemicals discharged from the desalination plant.

Data collected from this monitoring will be used to ensure compliance with established EQ (table 10). This includes ensuring that toxicant concentrations do not exceed the ninety percent species protection levels at the

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Section 5 Water Quality Management Framework end of the outfall pipelines for more than five percent of the time, or if relevant the 20th and/or 80th percentiles of reference distribution.

Ecosystem health monitoring Yearly monitoring will be undertaken at sites within the moderate and high ecological protection zones in the vicinity of Cape Preston to ensure compliance with EQC and the maintenance of EVs and EQOs. Sampling will also be undertaken for comparison purposes at a suitable reference site located to the east of SW Regnard Island, within the maximum ecological protection zone.

Sampling will be undertaken to determine physical and chemical characteristics of the water column, along with toxicant levels in marine water and sediments.

In the event that this program identifies an exceedance of an EQC, further investigations will be undertaken. If it is determined that an EV may be at risk, appropriate management action will be taken. This process is conceptualised in Figure 5-2 below.

Figure 5-2 Conceptual diagram providing guidance for maintenance of environmental quality (EPA, 2005)

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Performance Indicators Section 6

6 Performance Indicators The proposed performance indicators for monitoring the potential impacts of the desalination plant outfall are summarised in Table 6-1 below.

Table 6-1 Proposed performance indicators for desalination outfall management

Objective Criteria / Management Actions Timing Provide a high level of protection to the waters in Location of outfall chosen to ensure effective the region of Cape Preston, except for the mixing 4 ha mixing zones. Modelling conducted to zone surrounding the outfalls ensure discharge will be no greater than 5% above ambient for more than 1% of the time All social values will be protected (swimming and outside the mixing zone around Cape Preston fishing) (except within the mixing zone) Restrict the size of the mixing zone surrounding All outfall modelling based upon 4 ha mixing the diffusers to 4 ha zone Design The location and linear route of the pipeline and Phase diffuser has been chosen to ensure that sensitive habitats are not impacted. Dive surveys confirm Protect sensitive habitats from construction and no sensitive habitats in the vicinity of the pipeline layout of the pipeline location. Pipeline to be trenched into seabed, at edge of dredged harbour entrance and extending out to the diffuser. Each 4 ha mixing zone has been carefully Protect sensitive habitats from the operation of located to ensure that sensitive habitats are not the pipeline outfall impacted. Real-time physical parameters will be measured Develop monitoring and feedback programs for on-line within the outfall stream to ensure that the wastewater stream within the outfall to percentile deviations from intake water are not provide an early warning of potential risks to exceeded. environmental quality Water samples will be analysed for toxicants at the intake and outfall sites. Develop monitoring of ecosystem health An annual monitoring program will be conducted indicators in the receiving marine environment, to verify the compliance with established EVs and select appropriate control sites for inclusion and EQOs. in the monitoring programme Diffuser compliance monitoring to be undertaken. Ensure that salinity variation resulting from the Real-time, in-line monitoring of both ambient and Operations discharge is no greater than 5% above the discharge physical seawater parameters will ambient level for more than one percent of the enable data verification of compliance. Any time anywhere around Cape Preston (except exceedance will be quickly acted upon (subject within the mixing zone) to parameter and specifics to be developed) to ensure the 5% limit is not exceeded. Ensure that toxicant concentrations do not exceed the 90% species protection levels at the Sampling of intake and outfall streams will be end of the outfall pipe for more than 5% of the undertaken and combined for analysis of toxicant time, not exceed the 99% species protection concentrations. levels at the edge of the Moderate Protection Zone

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References Section 7

7 References Al-Shammiri, M, Sfar, M. & Al-Dawas, M. (2000), Evaluation of two different antiscalants in real operation at the Doha research plant. Desalination, 128:1-16

ANZECC & ARMCANZ (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality: Volume 2 - Aquatic Ecosystems - Rationale and Background Information.

Brown, B.E., Le Tissier, M.D,A., Scoffin, T.P. & Tudhope, A.W. (1990). Evaluation of the environmentasl impact of dredging on intertidal coral reefs at Ko Phuket, Thailand, using ecological and ohysiological parameters. Marine Ecology Progress Series 65. 273-281

Buceta, J.L. Fernandez-Tourquemada, Y., Gacia, E. Iners, O. Mas, J. Roero, J. Ruiz, J. Ruiz-Mateo, A. Sabah, S. & Sanchez-Uzaso, J.L. (2003). Investigacion conjunta sobre la tolerancia de Posidonia oceanica a incrementos de salinidad. Ingeniera Civil 132, 111-116

Butt, F. Rahman, F. Baduruthamal, U. (2007). Evaluation of SHMP and advanced scale inhibitors for control of Ca SO4, SrSO4, and CaCO3 scales in RO desalination. Desalination 109: 323-332/

CALM (2005). Indicative management plan for the proposed Dampier Archipelago Marine Park and Cape Preston Marine Management Area. Department of Conservation and Land Management, Western Australia.

Campey, M.L. & Gilmour, J.P. (2000). Baseline survey of benthic marine communities of Cape Preston and Preston Island. Prepared for Halpern Glick Maunsell Pty Ltd.

Chevron Australia (2005). Gorgon Development on Barrow Island. Technical Appendix C6 Protected Marine Species. Technical Report prepared for ChevronTexaco Australia Pty Ltd by RPS Bowman Bishaw Gorham. Report No: R03206, April 2005.

Coles S.L. (1992). Experimental comparison of salinity tolerances of reef corals from the Arabian Gulf and Hawaii. Evidence for hypersaline adaptation. Proc 7th International Coral Reef Symposium 1.

Danoun R. (2007). Desalination Plants: Potential impacts of brine discharge on marine life. University of Sydney, Australia. The Ocean Technology Group – Final Project

Department of the Environment and Heritage (May 2005): Humpback Whale Recovery Plan 2005 - 2010

DEC (2006), Pilbara coastal water quality consultation outcomes. Recommendations to EPA, March 2006. Department of Environment and Conservation, Perth, Western Australia.

Del Pilar Ruso, Y, Della Ossa Carretero, J.A., Gimenez Casalduero, F. & Sanchez Lizaso, J.L. (2007). Spatial and temporal changes in infaunal communities inhabiting soft-bottoms affected by brine discharge. Marine Environmental Research 64, 492-503.

Edmonds, J.S., Shibata, Y. Prince, R.I.T. Preen, A.R. & Morita, M. (1997). Elemental composition of a tusk of a dugong (Dugong dugon) from Exmouth, Western Australia. Marine Biology 129:203-14.

Environmental Protection Authority (2004). Guidance for the Assessment of Environmental Factors No. 29 Benthic Primary Producer Habitat Protection for Western Australia’s Marine Environment. Environmental Protection Authority, June 2004.

Fabricius, K., Wild, C., Wolanski, E. & Abele, D. (2003). Effects of transparent exopolymer particles (TEP) and muddy terrigenous sediments on the survival of hard coral recruits. Estuarine, Coastal and Shelf Science, 57, 613-621.

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Section 7 References

Fabricius K.E. (2005). Effects of terrestrial runoff on the ecology of corals and coral reefs: review and synthesis. Marine Pollution Bulletin 50, 125-146.

Falbe, J & Regitz, M (1995). Roempp Chemie Lexikon, 9th edition on CD ROM. Georg Thieme Verlag Stuttgart.

Fernandez-Torquemada, Y. Sabnchez-Lizaso, J.L. & Gonzales-Correra, J.M. (2005). Preliminary results of the monitoring of the brine discharge produced by the SWRO desalination plant of Alicante (SE Spain). Desalinantion 182 , 395-402.

Ferrier-Pages, C., Gattuso, J.P. & Jaubert, J. (1999). Effect of small variations in salinity on the rates of photosynthesis and respiration of the zooxanthellate coral Stylophora pistillata. Marine Ecology Progress Series 181, 309-314.

GEMS (2008). SINO Iron Project Cape Preston Port Development. Desalination Plant Brine Discharge Modelling Study. For URS on behalf of CP Mining Management P/L. May 2008.

Gilmour, J. (1999). Experimental investigation into the effect of suspended sediment on fertilisation, larval survival and settlement in a scleractinian coral. Marine Biology 135, 451-462

Griffith, J.K. (2004). ‘Scleractinian corals collected during 1998 from the Dampier Archipelago, Western Australia’; In. Jones, D.S. (ed.) Marine Biodiversity of the Dampier Archipelago Western Australia 1998-2002. Records of the Western Australian Museum Supplement No. 66, pp. 101-120.

Halpern Glick Maunsell (2002). Iron Ore Mine and Downstream Processing, Cape Preston, Western Australia. Supplementary Public Environmental Review, prepared for Austeel Pty Ltd by Halpern Glick Maunsell, Perth, Western Australia.

Hiscock , K. Southward, A.J., Tittley. I & Hawkins. S.J. (2004). Effect of changing temperature on benthic marine life in Britain and Ireland. Aquatic Conservation 14, 333-362

Höpner, T. & Windelberg. J. (1996). Elements of environmental impact studies on coastal desalination plants. Desalination 1996

Hőpner, T. & Lattemann, S. (2002). Chemical Impacts from Seawater desalination plants – a case study of the northern Red Sea. Desa;ination 152 133-140

IMCRA (1998). Interim Marine and Coastal Regionalisation for Australia: an Ecosystem-based Classification for Marine and Coastal Environment, Version 3.3. Environment Australia, Commonwealth Department of the Environment, Canberra.

Lattemann. S & Hőpner, T (2003). Seawater Desalination. Impacts of Brine and Chemical Discharges on the Marine Environment. pp142,

Lattemann (2007): EES must be conducted (Media statement www.cleanocean.org)

Lattemann, S. & Höpner, T. (2008). Environmental impact and impact assessment of seawater desalination. Desalination 220.

Larcombe, P., Ridd, P., Prytz, V. & Wilson, B. (1995). Factors controlling suspended sediment on inner-shelf coral reefs, Townsville, Australia. Coral Reefs 14, 163-171.

Maunsell (2006). Marine and Coastal Environmental Report. Prepared for Mineralogy Pty Ltd by Maunsell, Perth, Western Australia.

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References Section 7

Marsh, H., Penrose, H. Eros, C. & J. Hugues. (2002). Dugong: Status reports and action plan for countries and territories. UNEP Early Warning and Assessment Report Series.

Miri, R. & Chouikhi, A. (2005). Ecotoxicological marine impacts from seawater desalination plants. Desalination 182. 2005.

Münk (2008). Ecological and economic analysis of seawater desalination plants. Diploma Thesis , University of Karlsruhe, Institute for Hydromechanics, Karlsruhe 2008 pp108

Murphy, P.J. (1981). Visibility in seawater of Laporte effluent discharged from an ocean outfall. Department of Resources Western Australia. Assessment document.Proper citation here required. IAN

Muthiga, N.A., & Szmant, A.M. (1987). The Effects of Salinity Stress on the Rates of Aerobic Respiration and Photosynthesis in the Hermatypic Coral Siderastrea sidereal. Biological Bulletin 173, 539-551.

Oceanwise Environmental Scientists (2005). The Status of the Dugong in Exmouth Gulf. Report to Straits Salt Pty Ltd. September 2005.

Pendoley, K. & Fitzpatrick, J. (1999). Browsing of mangroves by green turtles in Western Australia. In: Godley, B. and A. Broderick (eds). Marine Turtle Newsletter No. 84. Newsletter of the IUCN/SSC Marine Turtle group. University of Glasgow, Glasgow, Scotland.

Perez, K.T. (1969). An orthokinetic response to rates of salinity change in two estuarine fishes. Ecology 50:454- 457.

Prince, R.I.T. (1986). Dugong in northern waters of Western Australia 1984. Western Australian Department of Conservation and Land Management, Technical Report No. 7, Western Australia.

Prince R.I.T. (2001). Aerial Survey of the Distribution and Abundance of Dugongs and Associated Macroinvertebrates Fauna - Pilbara Coastal and Offshore Region, WA, Completion Report. Prepared by: Marine Species Protection Program, Department of Conservation & Land Management, WA. Prepared for: Environment Australia. May 2001.

Prince, R.I.T., Anderson, P.K. & Blackman. D. (1981). The status and distribution of dugongs in Western Australia. In: Marsh, H. (ed.). The Dugong: Proceedings of a Seminar/Workshop held at James Cook University 8-13 May 1979. James Cook University of North Queensland, Townsville, Australia. pp. 67-87.

Prince, R.I.T., Rawlings M. & Selleck. R. (1995). Dugong adopts oil platform as a focal point for activity. Sirenews: Newsletter of the IUCN/SSC Sirenia Specialist Group 24: 6-7.

Perez-Talavera, J.L. & Ruiz J.J. (2001). Quesada identification of the mixing processes in brine diwscharges carried out in Barranco del Toro, south of Gran Canaria (Canary Islands). Desalination 139, 277-286

Raventos, N, Macpherson, E, & Garcı´a-Rubies A (2006). Effect of brine discharge from a desalination plant on macrobenthic communities in the NW Mediterranean. Marine Environmental Research 62, 1–14

Rogers, C.S. (1990). Responses of coral reefs and reef organisms to sedimentation. Marine Ecology Progress Series 62, 185-202.

Swan, J.M., Neff, J.M & Young, P.C. (1994). Environmental Implications of Offshore Oil and Gas Development in Australia- The Findings of an Independent Scientific Review. Christopher Beck Books.

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Section 7 References

Thomson-Becker, E. & Luoma, S. (1985). Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay. Hydrobiologia. 129, 91-107

URS (2007). Cape Preston Benthic Habitat Survey Report and Review. Unpublished Draft Report to CP Mining Management Pty Ltd by URS Australia Pty Ltd, Perth, Western Australia, Report No. R1241.

Veron, JE & Marsh, LM (1988), Hermatypic corals of Western Australia: records and annotated species list, Records of the Western Australia Museum, No. 29.

Watercycling (2007). http://watercycling.blogspot.com/2007/07/desal-brine-disposal.html

Wells, FE (1990), Comparative zoogeography of marine molluscs from northern Australia, New Guinea and Indonesia’, Veliger 33, pp. 140-144.

Wells, FE., Walker, D. & Jones, D.S. 2003. The marine flora and fauna of Dampier, Western Australia. Western Australian Museum, Perth.

West, K. & Van Woesik, R. (2001). Spatial and temporal variance of river discharge on Okinawa (Japan) : inferring the temporal impact on adjacent coral reefs. Marine Pollution Bulletin 42, 864-872

Wilson, BR & Allen, GR (1987), Major components and distribution of marine fauna; in Dyne GR & Walton DW (eds), Fauna of Australia, General Articles, Volume 1A, Australian Government Publishing Service, Canberra, pp. 43-68.

Woodworth, J. (2008). The provision of water quality monitoring services for the Perth Seawater Desalination Plant; WET Testing. Final report prepared for Water Corporation. Available at: www.watercorporation.com.au/_files/PublicationsRegister/15/PER/32_WET_Testing_PSDP.pdf

World Health Organization, Public Health and the Environment, Geneva (2007). Desalination for Safe Water Supply. Guidance for the Health and Environmental Aspects Applicable to Desalination. pp 161

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Limitations of Report Section 8

8 Limitations of Report

URS Australia Pty Ltd (URS) has prepared this report in accordance with the usual care and thoroughness of the consulting profession for the use of International Minerals Pty Ltd and only those third parties who have been authorised in writing by URS to rely on the report. It is based on generally accepted practices and standards at the time it was prepared. No other warranty, expressed or implied, is made as to the professional advice included in this report. It is prepared in accordance with the scope of work and for the purpose outlined in our e-mail dated 18 June 2008.

The methodology adopted and sources of information used by URS are outlined in this report. URS has made no independent verification of this information beyond the agreed scope of works, and URS assumes no responsibility for any inaccuracies or omissions. No indications were found during our investigations that information contained in this report as provided to URS was false.

This report was prepared between June and September 2008 and is based on the conditions encountered and information reviewed at the time of preparation. URS disclaims responsibility for any changes that may have occurred after this time.

This report should be read in full. No responsibility is accepted for use of any part of this report in any other context or for any other purpose or by third parties. This report does not purport to give legal advice. Legal advice can only be given by qualified legal practitioners.

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON Cape Preston Preliminary Water Quality Investigations Appendix A

A Cape Preston Preliminary Water Quality Investigations

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SINO IRON PROJECT

Cape Preston Preliminary Water Quality Investigations

Prepared for

CITIC Pacific Mining Management Pty Ltd

Level 10, 30 The Esplanade Perth WA 6000 Australia

J:\Jobs\43177570\6 Deliv\Balmoral South PER input\Desalination Section\Appendices\Appendix A 42906698 R1336 CP WQ Initial Investigations and Design of Baseline Monitoring Program Final 30 Jun 08.doc Cape Preston Preliminary Water Quality Investigations 30 June 2008 42906698-1892 : R1336

Project Manager: …………………………………… Ian LeProvost URS Australia Pty Ltd Senior Environmental Advisor

Level 3, 20 Terrace Road Project Director: East Perth …………………………………… WA 6004 Ian Baxter Australia Principal Marine Environmental Scientist Tel: 61 8 9326 0100 Fax: 61 8 9326 0296

Author ……………………..………….. Petra Ringeltaube Marine Ecologist

Date: 30 June 2008 Ref: 42906698-1892 [DK:M&C2903/PER] Status: Final Draft

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Contents

Contents 1 Introduction ...... 1-1 1.1 Background ...... 1-1 1.2 Purpose of the document...... 1-1 2 Initial Investigations...... 2-1 2.1 Scope of sampling undertaken ...... 2-1 2.2 Physical water column characteristics (in situ)...... 2-2 2.2.1 Material and method...... 2-2 2.2.2 Results...... 2-2 2.3 Chemical parameters and physical characteristics (laboratory)...... 2-9 2.3.1 Material and method...... 2-9 2.3.2 Results 2007...... 2-9 2.3.3 Results 2008...... 2-10 2.4 Nutrients, chlorophyll a, phaeophytin ...... 2-12 2.4.1 Material and method...... 2-12 2.4.2 Results...... 2-12 2.5 Phytoplankton and bacteria...... 2-13 2.5.1 Material, method and results ...... 2-13 2.6 Particle size distribution (PSD) ...... 2-14 2.6.1 Material, methods and results ...... 2-14 2.7 Silt density index (SDI)...... 2-14 2.7.1 Material, method and results ...... 2-14 3 Reference...... 3-1 4 Limitations of Report ...... 4-2

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Tables, Figures

Tables, Figures Tables Table 2-1 Sampling dates and general monitoring tasks...... 2-1 Table 2-2 Physico-chemical water column characteristics - summary ...... 2-3 Table 2-3 Parameters determined during the surveys in 2007 at the intake location and control site . 2- 10 Table 2-4 Parameters measured in February and March 2008...... 2-11 Table 2-5 Parameters measured on 16 May 2008 ...... 2-12 Table 2-6 Results from the 2007 surveys at the intake area ...... 2-13 Table 2-7 Phytoplankton cell densities (2007) ...... 2-13 Table 2-8 Particle size volume distribution 2007 surveys...... 2-14 Table 2-9 Silt Density Index (SDI)...... 2-15

Figures Figure 1-1 Cape Preston water quality sampling locations...... 1-2 Figure 2-1 Floating Sargassum ...... 2-4 Figure 2-2 Oxygen saturation at the deep water control site at different times during the day (3 February 2008) ...... 2-5 Figure 2-3 Oxygen at deep water control sites - 3 February 2008...... 2-6 Figure 2-4 Oxygen at intake location - 11 March 2008 ...... 2-6 Figure 2-5 Turbidity (NTU) at the deep water control site - 3 February 2008 ...... 2-7 Figure 2-6 Turbidity (NTU) at intake location - 11 March 2008...... 2-7 Figure 2-7 Mean pH values (±SE) at Cape Preston at all sites (data are pooled over depth)...... 2-8 Figure 2-8 pH at deep water control site and intake location - 3 February and 11 March 2008...... 2-8

Error! No table of figures entries found. Error! No table of figures entries found.

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 1 Introduction

1 Introduction

1.1 Background

CITIC Pacific Mining Management Pty Ltd (CPMM) has purchased the mining rights for the George Palmer ore-body from Mineralogy Pty Ltd via the Sino Iron takeover agreement. The Sino Iron Project is located approximately 80 km southwest of the regional centre of Karratha and 1200 km north of Perth. Magnetite ores will be sourced from the George Palmer Iron Ore deposit. The ore body is located 25 km south of Cape Preston from where magnetite products will be exported to international markets. The Project is a greenfields site and will require the development of dedicated infrastructure due to its remote location. CPMM will construct and operate the mine, processing plant and a port. Of key importance to the mine and magnetite beneficiation will be the installation of a seawater desalination plant at the port. The desalination plant will obtain its raw water feed from an intake near Cape Preston and will discharge brine concentrate, filtrate and minor concentrations of chemical additives into the marine waters offshore from Cape Preston.

1.2 Purpose of the document

Since February 2007, URS has undertaken a number of opportunistic water quality surveys in the vicinity of Cape Preston to better define the characteristics of the waters in the vicinity of the Cape. These surveys have been conducted primarily to obtain information required for the design of the desalination plant, but also to build up a preliminary baseline of data against which to assess potential impacts of the brine discharge and establish a water quality management framework for the port and brine outfall. To date, surveys have been opportunistic rather than regular and have focused on the summer period of 2007 and 2008 in an effort to record extreme values resulting from cyclones and run-off from the mainland. Unfortunately, no such events have occurred during the monitoring period to date. Nine surveys in total have been undertaken. This document summarises the water quality data that has been collected to date in the vicinity of Cape Preston by URS. The outcome of the surveys is a summary table of water quality characteristics for Cape Preston. The sampling locations are shown in Figure 1-1. The intake site and the ADCP control have been sampled most frequently. The offshore control and the outfall location have only been sampled on the one occasion each.

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 1 Introduction

Figure 1-1 Cape Preston water quality sampling locations

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations

A. Collated data

2 Initial Investigations

2.1 Scope of sampling undertaken

Data have been collected on nine occasions (Table 2-1) in the vicinity of the proposed intake and outfall sites (labelled as Intake site throughout the document), as well as at a control site (labelled ADCP throughout the document). Data have also been collected at a deep-water control site (3 February 2008), and at the proposed brine outfall location (16 May 2008) (Figure 1-1). Table 2-1 below outlines sample dates and general scope of works undertaken.

Table 2-1 Sampling dates and general monitoring tasks Chemical parameters Chemical Species Identification Identification Species Particle size analysis Particle size & Total Suspended Suspended & Total Field observation Field &Chlorophyll a &Chlorophyll characteristics characteristics Phytoplankton and cell count and cell Weather data Weather Solids (TSS) Sites visited Nutrients Physical Others Date SDI

27.02.07 Intake √ once daily √ √ √ √

22.03.07 Intake √ once daily √ √ √ √ √ √ √ ADCP = Control

04.04.07 Intake √ once daily √ √ √ √ √ √ √ Bacteria ADCP = Control

19.04.07 Intake √ once daily √ √ √ √ √ √ ADCP = Control 03.05.07 Intake √ √ √ √ √ √ ADCP = Control

07.06.07 Intake √ once daily √ √ √ √ √ √ ADCP = Control 03.02.08 Deep water Control √ hourly √ √ 11.03.08 Intake √ hourly √ √

15.05.08 Directly at outfall √ once daily √

Note that the sampling of specific chemical parameters varied on most occasions as information was being collected on request of the desalination plant design engineers. As indicated previously sampling focused on the summer months in an effort to collect extreme values of salinity, temperature and TSS. No sampling has been undertaken during the months July-January. The February and March 2008 samplings sampled physical parameters on an hourly basis over both a neap and spring tide to provide an indication of tidal variability in parameter concentration. In addition an intense sampling was undertaken in February 2008 with replicate samples being sent to three separate laboratories for analysis to determine reliability of analytical results. As a consequence only results analysed by the marine and Freshwater laboratory at Murdoch University have been reported.

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Section 2 Initial Investigations

The summary results and findings for each of the sampling tasks listed in the above table is outlined below.

2.2 Physical water column characteristics (in situ)

Physical characteristic of the water column have been determined in the field (in situ) using a multiprobe direct reading meter. Occasionally the instrument failed and the obtained data appeared unreliable. Where this occurred, the data have been excluded.

2.2.1 Material and method

• Characteristics determined

– water depth (m) – turbidity (NTU) – temperature (°C) – oxygen (mg/L & % saturation) – pH – salinity (ppt)

• Method

– Profiles have been taken once per day throughout the entire water column. On two occasions however (3 February 2008 and 11 March 2008) profiles have been taken hourly. These two datasets are presented separately. • Instrument used

– Eureka Manta – Water Quality Multiprobe

2.2.2 Results

Table 2-2 summarises the data collected in 2007 and the survey undertaken on 15 May 2008. These are the results from the observation made once per day. The data presented are pooled over depth per site.

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Section 2 Initial Investigations

Table 2-2 Physico-chemical water column characteristics - summary

Temperature (°C) Salinity (ppt) Site Date means minimum maximum Site Date means minimum maximum Intake 27-Feb-07 30.60 29.74 31.76 Intake 27-Feb-07 35.94 35.70 36.10 Intake 22-Mar-07 30.20 29.86 30.83 Intake 22-Mar-07 36.14 35.80 36.80 Intake 4-Apr-07 30.18 30.17 30.19 Intake 4-Apr-07 37.19 37.00 37.30 Intake 19-Apr-07 30.24 30.23 30.25 Intake 19-Apr-07 37.34 37.20 37.50 Intake 7-Jun-07 23.49 23.23 23.57 Intake 7-Jun-07 ADCP 27-Feb-07 ADCP 27-Feb-07 ADCP 22-Mar-07 29.94 29.92 29.96 ADCP 22-Mar-07 35.90 35.90 35.90 ADCP 4-Apr-07 30.00 29.98 30.02 ADCP 4-Apr-07 36.97 36.80 37.10 ADCP 19-Apr-07 30.23 30.21 30.26 ADCP 19-Apr-07 37.41 37.30 37.50 ADCP 7-Jun-07 23.41 23.39 23.43 ADCP 7-Jun-07 ADCP 15-May-08 26.55 26.54 26.56 ADCP 15-May-08 35.14 35.10 35.20

DO (mg/L) DO (%) Site Date means minimum maximum Site Date means minimum maximum Intake 27-Feb-07 5.96 5.49 6.22 Intake 27-Feb-07 99.99 90.91 105.23 Intake 22-Mar-07 6.77 6.33 7.39 Intake 22-Mar-07 112.85 104.87 123.61 Intake 4-Apr-07 8.74 8.70 8.82 Intake 4-Apr-07 144.05 142.80 145.60 Intake 19-Apr-07 6.87 6.84 7.08 Intake 19-Apr-07 115.16 114.70 116.10 Intake 7-Jun-07 8.81 8.70 8.90 Intake 7-Jun-07 ADCP 27-Feb-07 ADCP 27-Feb-07 ADCP 22-Mar-07 6.87 6.82 6.95 ADCP 22-Mar-07 113.94 113.18 115.24 ADCP 4-Apr-07 8.29 8.12 8.38 ADCP 4-Apr-07 136.13 132.80 137.80 ADCP 19-Apr-07 6.85 6.67 6.89 ADCP 19-Apr-07 115.31 113.56 115.79 ADCP 7-Jun-07 8.74 8.50 8.90 ADCP 7-Jun-07 ADCP 15-May-08 6.67 6.63 6.71 ADCP 15-May-08 100.64 100.00 101.30

pH Turbidity (NTU) Site Date means minimum maximum Site Date means minimum maximum Intake 27-Feb-07 8.21 8.17 8.22 Intake 27-Feb-07 2.69 1.10 11.10 Intake 22-Mar-07 8.20 8.17 8.35 Intake 22-Mar-07 2.28 1.50 6.40 Intake 4-Apr-07 7.62 7.53 7.66 Intake 4-Apr-07 22.35 20.20 22.70 Intake 19-Apr-07 8.40 8.38 8.42 Intake 19-Apr-07 2.24 1.90 3.10 Intake 7-Jun-07 8.11 8.10 8.12 Intake 7-Jun-07 3.45 3.10 3.60 ADCP 27-Feb-07 ADCP 27-Feb-07 ADCP 22-Mar-07 8.18 8.17 8.20 ADCP 22-Mar-07 2.46 2.00 3.40 ADCP 4-Apr-07 7.81 7.76 7.94 ADCP 4-Apr-07 22.43 22.30 22.60 ADCP 19-Apr-07 8.39 8.38 8.41 ADCP 19-Apr-07 2.08 1.90 2.30 ADCP 7-Jun-07 8.12 8.12 8.12 ADCP 7-Jun-07 3.21 2.60 3.70 ADCP 15-May-08 8.64 8.64 8.67 ADCP 15-May-08 0.77 0.30 2.10 Note: Data are pooled over depth

Temperature Temperature various naturally with season. The highest value (31.76oC) was recorded in February 2007 and the lowest (23.43oC) in June 2007. During the survey undertaken on 15 May 2008, a significant warm water body, a narrow band of approximately 2 m width and 1 m thickness, was observed containing a considerable amount of particulate organic material, including Sargassum sp. (Plate 2-1). It is assumed that water heats up in shallow tidal creek areas during high tide and this ‘warm water’ is carried out of the creeks during low tide, while its movement ‘catches’ particulate matter due to density differences.

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Section 2 Initial Investigations

Figure 2-1 Floating Sargassum

Salinity Salinity ranged from a minimum of 35.1 ppt in 2008 to a maximum of 37.5 ppt on 19 April 2007. In general it was observed that the highest salinity values (37.5 ppt) were recorded on 4 April and 19 April 2007, which coincided with an algal bloom event (see 2.6.1).

Oxygen Except on one occasion (27 February 2007) the water was always saturated (≥100%) with oxygen (see Table 2-2). Oxygen values, however, varied considerably during the day, as evident in the dataset collected every hour at the beginning of 2008 (Figure 2-3). At the intake area oxygen values were below 95% in the morning and above 100% in the late afternoon. This contrasts with profile data from the deep water control site, where oxygen saturation dropped in bottom waters in the afternoon (Figures 2-4 and 2-5).

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Section 2 Initial Investigations

Dissolved Oxygen Saturation 03.02.08 Deep Water Control Site 9:36 PM

7:12 PM

4:48 PM

2:24 PM Time

12:00 PM

9:36 AM

7:12 AM 82 84 86 88 90 92 94 96 98 100 102 104 106 108 Dissolved oxygen (% Saturation)

Figure 2-2 Oxygen saturation at the deep water control site at different times during the day (3 February 2008)

Turbidity Turbidity ranged from 0.3 NTU to 22.3 NTU (see Table 2.2). The highest readings were recorded for 4 April 2007 which coincided with an algal boom event (see 2.6.1). Turbidity readings taken hourly throughout the day (3 February 2008 – deep water control site) ranged between 1.6 to 7.5 NTU with an average of 2.7 NTU. The readings at the intake site (11.03.05) were similar with a minimum of 1.9, maximum of 6.2 and an average of 2.9 NTU. At both sites, the readings varied throughout the water column (Figure 2-6 and Figure 2-7) and also throughout the day. pH pH values ranged from a minimum of 7.53 to a maximum of 8.67 (see Table 2-2). The lowest readings (7.53) coincided with an algal bloom event (see 2.6.1) and was statistically significant lower (p<0.05) than the remaining readings (Figure 2-8). The measurements undertaken hourly showed minimal variations throughout the water column and during different times of the day (Figure 2-9). Note the scale of the x-axes.

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Section 2 Initial Investigations

03 February - Cape Prestion - Oxygen at Deep Water Control Site 11 March 08 - Cape Preston - Oxygen at Intake Location

Dissolved oxygen saturation (%) Dissolved oxygen saturation (%) 84.00 86.00 88.00 90.00 92.00 94.00 96.00 98.00 100.00 102.00 104.00 106.00 90.00 92.00 94.00 96.00 98.00 100.00 102.00 104.00 106.00 108.00 110.00 112.00 114.00 116.00 0.0 0.0

1.0 2.0 8:35am 8:45 18:35pm 17:45 2.0 4.0

3.0 6.0

4.0

8.0 depth (m) depth

depth (m) depth 5.0

10.0 6.0

12.0 7.0

14.0 8.0

16.0 9.0

Figure 2-4 Figure 2-5

Figure 2-3 Oxygen at deep water control sites - 3 February 2008

Figure 2-4 Oxygen at intake location - 11 March 2008

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Section 2 Initial Investigations

03 February 08 - Cape Preston - Turbidity at Deep Water Control Site 11 March 08 - Cape Preston - Turbidity at Intake Location

Turbidiy (NTU) Turbidiy (NTU) 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 0.0 0.0

1.0 2.0

11:45 2.0 4.0 17:45 8:35 3.0 17:35

6.0 4.0

8.0 5.0 depth (m) depth (m) 6.0 10.0

7.0 12.0 8.0

14.0 9.0

16.0 10.0

Figure 2-6 Figure 2-7

Figure 2-5 Turbidity (NTU) at the deep water control site - 3 February 2008

Figure 2-6 Turbidity (NTU) at intake location - 11 March 2008

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations

8.5 Mean ph values Ca pe Preston 03 February & 11 March 08 - Cape Prestion - pH at Deep Water Control & Intake Location 8.4 pH 8.2 8.3 8.4 8.5 8.6 8.3 0.0

8.2 2.0

8.1 4.0

6.0 8.0 Values 8.0 7.9 depth (m) depth

10.0

7.8 03 Feb-8:45-Control site 12.0 03 Feb-17:45-Control site 11 March-8:35-Intake 7.7 11 March-18:45-Intake 14.0 7.6 27-Feb-07 22-Mar-07 4-Apr-07 19-Apr-07 7-Jun-07 16.0 mean (+-SD) Date

Figure 2-8 Figure 2-9

Figure 2-7 Mean pH values (±SE) at Cape Preston at all sites (data are pooled over depth)

Figure 2-8 pH at deep water control site and intake location - 3 February and 11 March 2008

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations

2.3 Chemical parameters and physical characteristics (laboratory)

In 2007 URS undertook a total of six water quality surveys between February and June 2007 (see Table 2-1). The parameters measured are a combination of requests from CPMM and EPA, and URS recommendations. Overall, 62 parameters (Table 2-3) were measured over the period of the six surveys. In 2008 URS has undertaken two more surveys (3 February 2008 and 11 March 2008) which focused on the determination of total suspended solids (TSS), alkalinity, chloride, calcium and iron. The last survey (16 May 2008) focused on the determination of dissolved metals and total suspended solids. Due to different methods and sampling sites used during the 2007 and 2008 surveys, the results are presented separately.

2.3.1 Material and method

• Water Sampling 2007: Water was collected mid water via a Niskin bottle. Three replicate samplings were taken per location.

• Water Sampling 2008: Discrete surface and bottom samples were taken using a Niskin bottle. One replicate sample per surface and bottom water was analysed.

• The collected water was stored and transported to the relevant laboratories according to their guidelines.

2.3.2 Results 2007

Table 2-3 summarises the 2007 results which have been pooled over date and site, providing numerical values of the range. None of the parameters measured exceeded background levels outlined in ANZECC (2000) guidelines. The data showed no differences among replicate samples and no obvious differences among sites. Discrepancies occurred with the analyses for Total Suspended Solids (refer to 2.4.3).

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Section 2 Initial Investigations

Table 2-3 Parameters determined during the surveys in 2007 at the intake location and control site

Parameters determined during the surveys in 2007 at the Intake and Control site Data are pooled over time and site (Intake and Control)

Parameter Range Parameter Range Dissolved Metals (mg/L) Total Metals (mg/L) Aluminium <0.10 Arsenic <0.010 Aluminium 0.01-0.04 Beryllium <0.010 Barium <0.01-0.02 Cadmium <0.001 - 0.0016 Manganese <0.001 Chromium <0.010 Strontium 7.2-9 Copper 0.011 Boron 3.1-5.1 Lead <0.010 Iron max 0.24 Manganese <0.010 Bromine 56-89 Nickel <0.010 Mercury <0.0001 Zinc <0.050 Silica <0.1 Iron <0.1-0.28 Boron 3.8 - 4 Bromine 61-77

Others (mg/L) Alkalinity by PC Titrator (mg/L) Chemical Oxygen Demand 889-5440 Hydroxide Alkalinity as CaCO3 <1 Trivalent Chromium <0.010 Carbonate Alkalinity as CaCO3 <1 Hexavalent Chromium <0.002 Bicarbonate Alkalinity as CaCO3 111-128 Total Dissolved Solids @180°C 31800-48900 Total Alkalinity as CaCO3 111-128 Suspended Solids (SS) 17-346 Total Organic Carbon <1-10 Oil & Grease <5 Colour (True) no unit <0.1-<1 pH Colour (no unit) 7.68-8.37 Turbidity (NTU) <0.1-1.1 Total Hardness as CaCO3 654-7050

Ionic Balance (mg/L) Dissolved Major Anions (mg/L) Total Anions 588-694 Sulphate as SO4 2- 2870-3500 Total Cations 610-693 Sulphur as S 957-1170 Ionic Balance 0.06-4.86 Silicon <0.25 Chloride 18600-22300

Total Hardness as CaCO3 654-7050 Dissolved Major Cations (mg/L) Calcium 416-533 Magnesium 1240-1460 Sodium 10800-12300 Potassium 403-575 Note: Data are pooled over time and site (intake and control)

2.3.3 Results 2008

Table 2-4 summarises the results from the deep water control site (3 February 2008), the proposed water intake site (11 March 2008), and two coral sites (NPS North Preston Spit and SW Regnard). Note that TSS analysis has been undertaken by various laboratories as discrepancies with respect to

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations the results were identified in 2007. Table 2-4 presents only the results from the Marine and Freshwater Laboratory (MAFRL), as they are considered reliable. None of the background levels exceeded values recommended by ANZECC (2000).

Table 2-4 Parameters measured in February and March 2008

Hydroxide Alkalinity Carbonate Bicarbonate Total as Alkalinity as Alkalinity as Alkalinity Date Site Method NChlorideTSS Ca * CaCO3* CaCO3* CaCO3* as CaCO3* mg/L mg/L mg/L mg/L mg/L mg/L mg/L Deep water Surface 11 18909.09 5.2* 423.6* 123.36 123.36 03.02.08 control <1 <1 Deep water Bottom 12 19250.00 5.8* 423.3* 124.50 124.50 03.02.08 control <1 <1 03.02.08 NPS mid water 4 5.20 03.02.08 SWR mid water 4 5.80 11.03.08 Intake Surface 12 22916.00 4.5* 410.8* 11.03.08 Intake Bottom 12 21666.00 5.25* 410.8* 11.03.08 NPS mid water 4 4.35 11.03.08 SWR mid water 4 3.75

* statistically (ANOVA) no significant differences detected between surface and bottom

Table 2-5 shows the results for the metal and TSS concentrations at the outfall site. All data were tested statistically to identify any differences between surface and bottom samples. At all sites no significant differences were detected between surface and bottom samples and this holds true for all parameters measured. Except for boron and lead (highlighted in green in the Table 2-6), none of the background levels exceeded ANZECC guideline values for ecosystem protection.

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Section 2 Initial Investigations

Table 2-5 Parameters measured on 16 May 2008

Parameters measured at the 16.05.08 Close to Outfall site displayed are means (n=3) ANZECC Parameter (mg/L) Surface Bottom 99% species protection TSS 1.36 5.23 N/A Aluminium filtered <0.005 <0.005 0.0005 Arsenic filtered 0.00166667 0.001666667 N/A Barium filtered 0.007 0.76 N/A Beryllium filtered <0.001 <0.001 N/A Boron filtered 5.63 5.6 5.1 Cadmium filtered <0.0001 <0.0001 0.0007 Chromium filtered <0.001 <0.001 N/A Copper filtered <0.001 <0.001 0.0003 Iron filtered <0.005 <0.005 N/A Lead filtered 0.008 <0.001 0.0022 Manganese filtered <0.001 <0.001 0.08 Mercury filtered <0.0001 <0.0001 0.0001 Nickel filtered <0.001 <0.001 0.007 Strontium filtered 6.53 7.56 N/A Zinc filtered <0.001 <0.001 0.007 Bromide 94.33 82.00 N/A

all values have been calculated with 3 replicates each

2.4 Nutrients, chlorophyll a, phaeophytin

2.4.1 Material and method

• Water sampling took place on six occasions at the Intake site only. Three replicate samples were taken per site. Water was collected mid water via a Niskin bottle.

• Data were analysed by MAFRL.

2.4.2 Results

The results for the nutrients, chlorophyll a and phaeophytin are shown in Table 2-6. Values are shown as ranges. Ammonia, NOx, total P, total N and pH background values all exceeded the recommended ANZECC guideline values (all highlighted in green) for ecosystem protection.

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations

Table 2-6 Results from the 2007 surveys at the intake area

Nutrients, chlorophyll and phaeophytin Results from the 2007 surveys at the Intake area Data have been pooled over time

ANZEEC guidelines for ecosystem protection Parameter Range (µg/L) Range (µg/L) Ammonia <3-53 1-10 Ortho -P 3-6 5 NO3+NO2 <2-210 2-8 NO2 <2 N/A Total P <5-11 15 Total N 100-310 100 Chlorophyll a 0.8-1 0.7-1.4 Phaeophytin 0.3-0.6 N/A pH 8-2-8.6 8.0-8.4

2.5 Phytoplankton and bacteria

2.5.1 Material, method and results

Phytoplankton

• Water sampling for phytoplankton analysis took place on two occasions at the intake site (Table 2-7). Three replicate samples (mid water via a Niskin bottle) were taken per day. Phytoplankton species identification and cell densities were determined and reported on by DALCON.

Table 2-7 Phytoplankton cell densities (2007)

Shown are means (n=3)

Date 22.03.07 04.04.07 Site Intake Intake

Total number of cells/L 256,706 657,342

Bacillariophyceae (% of total cell number) 62 29 Cyanobacteria (% of total cell number) 17 62 Dinophyceae (% of total cell number) 1 0 Prasinophyceae (% of total cell number) 18 8 Cryptophyceae (% of total cell numbers) 0 0 Unknow (% of total cell number) 0 0 Chlorophyta (% of total cell number) 3 0 On 4 April 2007 an algal bloom (‘high’ number of cells) event was identified. The species responsible for the high cell numbers is Trichodesmium erythraea (note that it has been named Oscillatoria

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations erythraea in the original DALCON report). T. erythraea is a potentially toxic blue green algae and has frequently been observed in the area (Maunsell 2002). As mentioned earlier (2.3.2), this algal bloom coincided with high salinity, a 10 fold increased TSS reading (>20 NTU) and significant lower ph values.

Bacteria

• Samples for bacteria (Enterococci) were collected on 4 April 2007 only. The data were analysed by PathWest. The Enterococci counts ranged from 30 – 130 CFU/mL.

2.6 Particle size distribution (PSD)

2.6.1 Material, methods and results

• Water sampling took place on five occasions (Table 2-8) and three replicate samples were taken per site per day. Data was analysed by CSIRO. The results (see Table 2-8 for mean values) showed that on all occasions the silt (4-62 µm) section was the dominant (%volume) fraction present.

Table 2-8 Particle size volume distribution 2007 surveys

Shown are means (n=3) of % volume of count distribution

Clay Silt Fine Sand Sand 0-4µm 4-62µm 62-250µm > 250µm Site Date % Volume % Volume % Volume % Volume Intake 22/03/2007 1.24 75.70 23.06 0.00 Intake 4/04/2007 3.86 84.94 11.20 0.00 Intake 19/04/2007 0.72 90.32 8.96 0.00 Intake 3/05/2007 3.28 90.63 6.09 0.00 Intake 7/06/2007 1.40 92.66 5.94 0.00 nr = not reported by lab, count distribution data available only - refer to lab reports

2.7 Silt density index (SDI)

2.7.1 Material, method and results

Water sampling took place on five occasions, samples were collected at different water depth (Table 2-9) and replicate sampling varied throughout the dates. Data were analysed by AWS and results are presented below.

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 2 Initial Investigations

Table 2-9 Silt Density Index (SDI)

Data are from the 2007 survey in the Intake areaa SDI SDI SDI SDI Replicate Date Specifics 75%plugging 5 10 15 I1 22/03/2007 26.9 17.6 na np I2 22/03/2007 34.9 18.4 na np I3 22/03/2007 32.5 18.3 na np I1 4/04/2007 21.5 16.4 na 6.3 I2 4/04/2007 20.7 16.2 na 6.3 I3 4/04/2007 22.1 15.5 na 6.3 I1 19/04/2007 2 m from bottom na 17.3 na 6.4 I1 19/04/2007 7 m from bottom na 17.1 na 6.3 I2 19/04/2007 2 m from bottom na 17.5 na 6.4 I2 19/04/2007 7 m from bottom na 17.1 na 6.3 I1 3/05/2007 2 m from bottom 53 18.9 9.7 clogged I1 3/05/2007 7 m from bottom 64 19.0 9.7 6.5 I2 3/05/2007 2 m from bottom 56 19.1 9.7 6.5 I2 3/05/2007 7 m from bottom 66 19.0 9.7 6.5 I1 7/06/2007 2 m from bottom na 18.8 na 6.4 I1 7/06/2007 7m from bottom na 18.8 na 6.4 I2 7/06/2007 2 m from bottom na 18.9 na 6.4 I2 7/06/2007 7 m from bottom na 18.9 na 6.5

na = not analysed np = measurement not possible

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 3 Reference

3 Reference ANZECC & ARMCANZ (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Paper No.4 Volume 1 The Guidelines. Canberra, Auckland.

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CAPE PRESTON PRELIMINARY WATER QUALITY INVESTIGATIONS

Section 4 Limitations of Report

4 Limitations of Report URS Australia Pty Ltd (URS) has prepared this report in accordance with the usual care and thoroughness of the consulting profession for the use of CITIC Pacific Mining Management Pty Ltd and only those third parties who have been authorised in writing by URS to rely on the report. It is based on generally accepted practices and standards at the time it was prepared. No other warranty, expressed or implied, is made as to the professional advice included in this report. The methodology adopted and sources of information used by URS are outlined in this report. URS has made no independent verification of this information beyond the agreed scope of works, and URS assumes no responsibility for any inaccuracies or omissions. No indications were found during our investigations that information contained in this report as provided to URS was false. This report was prepared between June and July 2008, and is based on the conditions encountered and information reviewed at the time of preparation. URS disclaims responsibility for any changes that may have occurred after this time. This report should be read in full. No responsibility is accepted for use of any part of this report in any other context or for any other purpose or by third parties. This report does not purport to give legal advice. Legal advice can only be given by qualified legal practitioners.

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MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON Dugong Literature Review - Onslow to Dampier, WA Appendix B

B Dugong Literature Review - Onslow to Dampier, WA

Prepared for International Minerals Pty Ltd, 10 September 2008 Ref: 43177570-1892 : R1337 [DK:M&C2904/PER]

J:\Jobs\43177570\6 Deliv\Balmoral South PER input\Desalination Section\Appendices\Appendix B Dugong Literatue Reveiw (Letter).doc 11 July 2008 Project No. 43177570

International Minerals Pty Ltd Level 4, 5 Mill Street PERTH WA 6000

Attention: Mr Joe Webb

Dear Sir, Subject: Dugong Literature Review – Onslow to Dampier, WA

1. Introduction International Minerals Pty Ltd has commissioned URS Australia to provide a desktop survey report on the distribution, biology, ecology and threats to the dugong (Dugong dugon) in the North West Coastal region of Western Australia, between Onslow and Dampier. The dugong is the only member of the family Dugongidae and joins the northern hemisphere manatees as the only living representative of the order Sirenidae. Dugongs grow to about three metres long and can weigh up to 450kg.

2. Habitat and Distribution in North West Western Australia Dugong typically occur in the temperate shallow waters of the Indian and Pacific Oceans, but are most abundant in the marine waters of Northern Australia (Chevron Australia 2005). The species is sensitive to temperatures below approximately 20°C and tend to be found in warmer waters in winter (Chevron Australia 2005), although aerial survey data indicate the year-round presence of dugongs in Exmouth Gulf (Oceanwise 2005). Dugong are known to occur around the islands of the North West Shelf (Prince 2001), with a large concentration in Shark Bay, from Exmouth to the North Kimberly Coast, however, there is a general lack of understanding regarding fine-scale movements and the importance of various habitats for resting, breeding or feeding. Major concentrations of dugong tend to occur in wide shallow bays, wide shallow mangrove channels and in the lee of large inshore islands. Shallow waters such as tidal banks and estuaries have also been reporting as sites for calving (Oceanwise 2005).

URS Australia Pty Ltd (ABN 46 000 691 690) Level 3, 20 Terrace Road East Perth WA 6004, Australia Tel: 61 8 9326 0100 Fax: 61 8 9326 0296

Mr Joe Webb International Minerals Pty Ltd Level 4, 5 Mill Street PERTH WA 6000 11 July 2008 Page 2

The presence of dugongs is dependant on the distribution of tropical and subtropical seagrasses on which they feed (Edmonds et al. 1997). Dugongs are generally associated with shallow seagrass meadows which occur throughout the shallow waters between the offshore islands and the mainland (Chevron Australia 2005). A review of recent literature indicates that moderate concentrations of dugongs were observed in the region between Exmouth Gulf and De Grey River during shoreline surveys in the 1980’s, with most animals observed in areas such as Mangrove and Passage Islands, Regnard Bay, Nickol Bay and within the Dampier Archipelago (Prince et al. 1981, Prince 1986). In April 2000, a quantitative aerial survey of this area recorded 2,046 (± s.e. 376) dugongs at an average density of 0.10 dugongs per km2. Most of the dugongs were in the locations identified from the earlier surveys and incidental reports of sightings or strandings (Prince et al 1995, Marsh et al. 2002). Dugong feeding trails have been observed in dense seagrass meadows of Halodule and Halophila, between Middle and North Mangrove Islands (Pendoley & Fitzpatrick 1999). This region has extensive areas of shallow water, extending to the seaward side of Barrow Island and the Monte Bello Islands (Marsh et al. 2002). In surveys of Exmouth Gulf in October and November 2004, the majority (76%) of dugong herds sighted were in shallow (<6m) water (Oceanwise 2005). Regional quantitative surveys indicate a minimum population estimate of approximately 1,000 individuals in Exmouth Gulf during winter (Oceanwise 2005). Individual dugong have been occasionally sighted off the west coast of Cape Preston and SW Regnard Island during boat based field surveys carried out by URS during December 2006, June 2007, and May 2008 for Citic Pacific Mining Management’s Sino Iron Project at Cape Preston (LeProvost pers comm.).

3. Diet The dugong diet consists primarily of Halodule mixed with Cymodocea and Halophila seagrass, and feeding generally occurs over seagrass meadows at depths of five to ten metres (Chevron Australia 2005). They are wholly herbivorous and their seasonal movements and feeding grounds within the north western region are not well understood.

4. Reproduction and Life History Dugongs are believed to calve predominantly in August to September and produce one calf every three to seven years (Swan et al. 1994). The dugong is a long lived mammal with a life span of 50-60 years and a minimum of pre-reproductive period of 9-10 years for both sexes (Swan et al. 1994).

5. Conservation Status Dugong are listed a specially protected species of mammal under Schedule Four (‘fauna that need special protection’) of the WA Wildlife Conservation Act 1999 and threatened

Mr Joe Webb International Minerals Pty Ltd Level 4, 5 Mill Street PERTH WA 6000 11 July 2008 Page 3

(Vulnerable) marine and migratory species under the Environment Protection and Biodiversity Act 1999. Internationally, the World Conservation Union (IUCN) lists the dugong as vulnerable to extinction at a global scale. Dugong are listed on Appendix I of the Conservation of International Trade in Endangered Species (CITES), and on Appendix II of the Convention on Migratory Species (the CMS). Australia is a signatory to both these conventions.

6. Threats Localised threats to dugongs of industrial construction and operations within dugong habitat include seabed disturbance, physical interactions, light, noise and vibration, leaks and spills and cumulative impacts on the species (Chevron Australia 2005). Individual animals are likely to be impacted by these disturbances, however, population level effects are unlikely (Marsh et al. 2002). Some seagrass beds within Shark Bay show evidence of damage from boat traffic, and seismic surveying and petroleum activities in the Pilbara coastal region may affect dugongs. Effects on individuals and habitat through acoustic disturbance, eutrophication, pesticides, boat strikes or dragging moorings on the sea bed are caused by, but not limited to, human activities in dugong habitat. Some hunting of dugongs is known to exist in the Dampier Archipelago by indigenous hunters, but there are no records of dugong takes (Marsh et al. 2002). Finally, tourism and recreational boats and commercial trawling pose a threat to the species with reports of fatalities by boat collisions in the Pilbara region (Marsh et al. 2002). Small scale prawn fisheries operate from Onslow, and from Cape Lambert to Port Hedland, and pearling aquaculture operations are active within the Dampier Archipelago, but there is little knowledge available on the impact of these operations on dugong populations (Marsh et al. 2002).

7. References Chevron Australia 2005. Gorgon Development on Barrow Island. Technical Appendix C6 Protected Marine Species. Technical Report prepared for ChevronTexaco Australia Pty Ltd by RPS Bowman Bishaw Gorham. Report No: R03206, April 2005. Edmonds, J.S., Y. Shibata, R.I.T. Prince, A.R. Preen and M. Morita. 1997. Elemental composition of a tusk of a dugong (Dugong dugon) from Exmouth, Western Australia. Marine Biology 129:203-14. Marsh, H., H. Penrose, C. Eros, and J. Hugues. 2002. Dugong: Status reports and action plan for countries and territories. UNEP Early Warning and Assessment Report Series.

Mr Joe Webb International Minerals Pty Ltd Level 4, 5 Mill Street PERTH WA 6000 11 July 2008 Page 4

Oceanwise Environmental Scientists 2005. The Status of the Dugong in Exmouth Gulf. Report to Straits Salt Pty Ltd. September 2005. Pendoley, K. and J. Fitzpatrick. 1999. Browsing of mangroves by green turtles in Western Australia. In: Godley, B. and A. Broderick (eds). Marine Turtle Newsletter No. 84. Newsletter of the IUCN/SSC Marine Turtle group. University of Glasgow, Glasgow, Scotland. Prince, R.I.T. 1986. Dugong in northern waters of Western Australia 1984. Western Australian Department of Conservation and Land Management, Technical Report No. 7, Western Australia. Prince R.I.T. 2001. Aerial Survey of the Distribution and Abundance of Dugongs and Associated Macroinvertebrates Fauna - Pilbara Coastal and Offshore Region, WA, Completion Report. Prepared by: Marine Species Protection Program, Department of Conservation & Land Management, WA. Prepared for: Environment Australia. May 2001. Prince, R.I.T., P.K. Anderson, and D. Blackman. 1981. The status and distribution of dugongs in Western Australia. In: Marsh, H. (ed.). The Dugong: Proceedings of a Seminar/Workshop held at James Cook University 8-13 May 1979. James Cook University of North Queensland, Townsville, Australia. pp. 67-87. Prince, R.I.T., M. Rawlings and R. Selleck. 1995. Dugong adopts oil platform as a focal point for activity. Sirenews: Newsletter of the IUCN/SSC Sirenia Specialist Group 24: 6- 7. Swan, J.M., Neff, J.M and Young, P.C. 1994. Environmental Implications of Offshore Oil and Gas Development in Australia- The Findings of an Independent Scientific Review. Christopher Beck Books.

Yours faithfully, URS AUSTRALIA PTY LTD

Blair Hardman Senior Environmental Scientist

MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON Cape Preston Desalination Plant Brine Discharge Modelling Study Appendix C

C Cape Preston Desalination Plant Brine Discharge Modelling Study

Prepared for International Minerals Pty Ltd, 10 September 2008 Ref: 43177570-1892 : R1337 [DK:M&C2904/PER]

GEMS

GLOBAL ENVIRONMENTAL MODELLING SYSTEMS

GLOBAL ENVIRONMENTAL MAPPING SYSTEMS GLOBAL ENVIRONMENTAL MONITORING SYSTEMS

CAPE PRESTON

DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY

For URS on behalf of MINERALOGY P/L

May 2008

GEMS

GEMS CONTACT DETAILS

Melbourne Office Perth Office Telephone: +61 (0)3 8683 5405 Telephone: +61 (0)8 6364 0880 PO Box 149 PO Box 1432 Warrandyte VIC 3113 Subiaco WA 6097

Dr Graeme D Hubbert Matt Eliot Head of Oceanographic Studies Coastal Engineer Mobile: +61 (0)418 36 63 36 Mobile: +61 (0)408 414 225 Email: [email protected] Email: [email protected]

Steve Oliver Jason Catlin Head of Meteorological and Wave Studies Head of GIS Mapping Systems Mobile: +61 (0)408 81 8702 Mobile: +61 (0)407 048 458 Email: [email protected] Email: [email protected]

Website: www.gems‐aus.com

ABOUT GEMS

Global Environmental Modelling Systems (GEMS), a wholly owned Australian company, has expertise in the development and application of high‐resolution computer models to realistically predict atmospheric and oceanographic conditions for use in riverine, coastal and oceanic settings.

The GEMS team is made up of qualified and experienced physical oceanographers, meteorologists, numerical modellers and environmental scientists. GEMS is a leading developer of numerical models in Australia. It has developed a system of validated environmental models and rigorous analytical procedures that provide solutions to a variety of environmental, engineering and operational problems.

DISCLAIMER

This report and the work undertaken for its preparation, is presented for the use of the client. Global Environmental Modelling Systems (GEMS) warrants that the study was carried out in accordance with accepted practice and available data, but that no other warranty is made as to the accuracy of the data or results contained in the report.

This GEMS report may not contain sufficient or appropriate information to meet the purpose of other potential users. GEMS, therefore, does not accept any responsibility for the use of the information in the report by other parties.

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CONTENTS

1 Introduction...... 6

1.1 Objectives...... 8

1.2 Scope of Works...... 9

1.3 Verification of Model...... 9

1.4 Basis of Model ...... 9

2 Climate and Meteorology...... 11

2.1 Synoptic Overview...... 11

2.1.1 ‘Cool Season’...... 11

2.1.2 ‘Warm Season’...... 12

2.2 Annual and Seasonal Wind Roses...... 12

3 Meteorological forcing of the Ocean Current Model ...... 16

3.1 LAPS and Meso‐LAPS ...... 16

3.2 Selection of a Period of Representative Winds ...... 17

4. Oceanography...... 18

4.1 Bathymetry...... 18

4.2 Tides and Currents...... 21

4.3 Ocean Model Setup ...... 21

5. Brine Discharge Modelling...... 24

5.1 Outfall site selection...... 24

5.2 Brine dispersion RESULTS ...... 24

5.2.1 Option 1: Colocated brine discharges...... 24

5.2.2 Option 2: CPMM Outfall at Location B, Mineralogy Outfall at Location C...... 25

5.3 Residence Studies...... 26

5 REFERENCES...... 34

Appendix A: Model Descriptions...... 35

A.1 GCOM3D...... 35

A.2 Discharge Plume Modelling with PLUME3D...... 36

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TABLE OF FIGURES

Figure 1.1: Google Earth image of the Cape Preston study region...... 6

Figure 1.2: Potential brine outfall locations (A, B and C)...... 8

Figure 2.1: Example of ‘Cool Season’ synoptic evolution...... 11

Figure 2.2: Example of typical ‘warm season’ pattern...... 12

Figure 2.3: Annual wind rose for Barrow Island derived from the years 1999 to 2005...... 13

Figure 2.4: Wind rose for Barrow Island for January to March from 1999 to 2005...... 14

Figure 2.5: Wind rose for Barrow Island for April to June from 1999 to 2005...... 14

Figure 2.6: Wind rose for Barrow Island for July to August from 1999 to 2005...... 15

Figure 2.7: Wind rose for Barrow Island for September to December from 1999 to 2005...... 15

Figure 3.1: Analysis of the occurrence of easterly or westerly wind events compared with the average at Barrow Island during the years 1999 to 2005...... 17

Figure 3.2: Analysis of the occurrence of easterly or westerly wind events compared with the average at Cape Preston during the years 2001 to 2007...... 17

Figure 4.1 Bathymetry of the Cape Preston region. (Note depth in fathoms)...... 19

Figure 4.2 Cape Preston bathymetry. (Source Sandwell)...... 20

Figure 4.3: Northwest Shelf grid from Exmouth to Broome...... 22

Figure 4.4: Cape Preston nested grid...... 22

Figure 4.5: Example of the ebb tide off Cape Preston predicted by GCOM3D...... 23

Figure 4.6: Example of the flood tide off Cape Preston predicted by GCOM3D...... 23

Figure 5.1: Proposed location of 300m long diffuser...... 26

Figure 5.2: Mixing zone regions for 100%, 99% and 95% achievement of 40 dilutions levels for the “double” diffuser at location B...... 27

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Figure 5.3: Snapshot of the mixing zone during flood tide conditions...... 28

Figure 5.4: Snapshot of the mixing zone during ebb tide conditions...... 29

Figure 5.5: Snapshot of the mixing zone during low neap tides at slack water...... 30

Figure 5.6: Snapshot of the mixing zone during low spring tides at slack water...... 31

Figure 5.7: Percentage compliance with two 4Ha mixing zones at 100%, 99% and 95% levels for separate diffusers at locations B and C...... 32

Figure 5.8: Track of a particle over a 5 day period after release at the diffuser site during neap tides .33

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1 INTRODUCTION

GEMS has been engaged by URS to model the brine dispersion characteristics for a desalination plant to be constructed at Cape Preston (Figure 1.1) by Mineralogy Pty Ltd to supply potable water to their Iron Ore Project. The maximum water production capacity of the desalination plant is 64 GL/annum. The proposed plant is to be constructed at Cape Preston alongside another 64 GL/annum desalination facility constructed by CP Mining Management Pty Ltd (CPMM) to supply potable water to their Sino Iron Project. The two desalination plants will have an intake located inside a yet to be constructed nearshore port. The CPMM outfall is proposed to be located in 7m depth of water to the east of the port. The purpose of this study is to investigate two options for the location of the Mineralogy plant outfall:

a) Co‐located with the CPMM outfall (location B); and

b) At a separate location north of the port access channel (location C).

Another outfall location (location A) was investigated during studies for CPMM, and discounted on the grounds of potential impacts on Preston Island.

These locations are shown in Figure 1.2.

The work has been undertaken using two sophisticated numerical computer models:

1) The GEMS 3D Coastal Ocean Model (GCOM3D) to simulate the complex three‐dimensional ocean currents off Cape Preston; and

2) The GEMS 3D Plume Dispersion Model (PLUME3D) to simulate the mixing of the desalination reject waters with the ambient seawater.

Figure 1.1: Google Earth image of the Cape Preston study region.

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Figure 1.2: Potential brine outfall locations (A, B and C).

1.1 OBJECTIVES

The objectives of the modelling study were to assist Mineralogy select an appropriate brine discharge location and diffuser design to minimise the size of the Moderate Protection Mixing Zone surrounding the diffuser.

This mixing zone is defined in the Ministerial conditions as the region outside which the salinity variation resulting from the discharge is no greater than 5% above the ambient level for more than one percent of the time anywhere around Cape Preston.

Given the existence of the CPMM brine outfall the study needed to be conducted with the assumption that the CPMM outfall was fully operating at location B in Figure 1.2.

The major objective of the study was therefore to determine whether the two brine outfalls could be collocated or whether the Mineralogy outfall should be sited separately.

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1.2 SCOPE OF WORKS

The scope of works undertaken for this study include:

• Digitising the bathymetry in vicinity of Cape Preston from information supplied by Sandwell (2007);

• Running the GEMS 3D Coastal Ocean Model (GCOM3D) to simulate the complex 3D ocean currents off Cape Preston;

• Running the GEMS PLUME3D model to simulate the dispersal of the brine discharge and calculate the size of the mixing zone as defined in the Ministerial conditions outlined above.

1.3 VERIFICATION OF MODEL

The GCOM3D model has been verified against current and tide data collected by GEMS at Cape Preston since October 2006 and satellite tracked drogues released during a URS field survey in June 2007. Verification of the model is presented in a separate report (see GEMS 2008A and B).

1.4 BASIS OF MODEL

In summary the brine discharge characteristics modelled were as follows:

• The plant produces a maximum of 64 GL/annum of desalinated water and discharges approximately 252,000 m3/day of brine with a salinity of approximately 78 ppt. Modelling was based on assessing the size of the mixing zone outside which the salinity is no greater than 5% above the ambient level for more than one percent of the time.

• Outfall & Diffuser Options:

a) A protected outfall pipe will run approximately 800 m east of the breakwater and discharge through a 150m diffuser, constructed as an extension to the CPMM diffuser, at a bathymetric depth of approximately 6 m LAT.

b) A protected outfall pipe will run approximately 500 m north of the access channel and discharge through a 150m diffuser at a bathymetric depth of approximately 10 m LAT.

• The brine discharge pipe consists of a single 1.8m diameter pipe, partially buried and protected against wave energy.

• The diffusers from both the CPMM and Mineralogy outfalls consist of an in line set of 50 outlets, discharging vertically over a 150m length of pipe, each with equal flow, with nominally 100mm openings.

The dispersion modelling considered the discharge conditions below for both brine outfalls:

Outfall Flow, for modelling: 252,000 m3/day

Mixing Area Definition: The region, outside which the salinity is no greater than 5% above ambient values 99% of the time.

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The brine contains both concentrated dissolved solids (TDS) and concentrated suspended solids (TSS). The brine composition remains constant over various flow rates:

Total Dissolved Solids (TDS): 78.82 g/L

Temperature +2°C above ambient

Total Suspended Solids (TSS) Composition 45% inorganic solids (silt, clay and sand)

30% organic solids

25% Ferric hydroxide

< 1% flocculants (polymer based)

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2 CLIMATE AND METEOROLOGY

2.1 SYNOPTIC OVERVIEW

The ocean climate of Cape Preston is dependent on meteorological forcing across the region and beyond. In order to understand the nature of the seasonal and inter‐annual oceanographic response, it is important to have a working understanding of the general meteorology of the region.

The meteorology of the Northwest Shelf is controlled by two main seasons, referred to here, respectively as ‘cool’ and ‘warm’; there are short transition seasons between these two main seasons.

2.1.1 ‘COOL SEASON’

During the cooler months the winds over the region are controlled by a high‐pressure ridge; this ridge is a persistent feature over the southern part of Western Australia. The ridge drives easterly quarter winds across the shelf region. Frontal systems moving through mid‐latitudes periodically erode the ridge; wind gradients then shift to the northeast, with a subsequent shift through southwest to southeast following frontal passage. A new high pressure will then re‐establish the pattern; during this phase periods of more persistent and stronger easterly winds can be expected to influence Cape Preston.

During periods of comparatively lighter offshore gradient winds local weak sea breezes may develop along the coast, directionally dependent on the particular location. Figure 2.1 shows a typical synoptic sequence over the WA region during June.

Figure 2.1: Example of ‘Cool Season’ synoptic evolution.

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The sequence initially shows a strong high‐pressure system directing a north‐east pressure gradient over the Pilbara, then a weakening of this gradient as the high erodes under the influence of a mid‐latitude front and finally the re‐establishment of high pressure in the wake of the front.

2.1.2 ‘WARM SEASON’

During the warmer months, the sub‐tropical ridge migrates southwards and the dominant synoptic feature is a permanent heat trough that develops inland from the Pilbara coast. This pattern produces results quasi‐ permanent south‐west wind flow across the Shelf region. Fluctuations in the intensity and location of the heat trough as well as diurnal and local topographic influences affect day‐to‐day variations in wind direction and speed within the general south‐west flow.

Figure 2.2 shows a typical synoptic pattern over the WA region during January. During this period, the winds at Cape Preston are controlled by the location and intensity of the Pilbara heat low.

Figure 2.2: Example of typical ‘warm season’ pattern.

2.2 ANNUAL AND SEASONAL WIND ROSES

The Bureau of Meteorology holds data for a number of sites in the Pilbara region including Barrow Island, Karratha Airport and Onslow. Since these sites are remote from Cape Preston it is well recognized that winds from these locations will not directly represent the wind regime in waters off Cape Preston. However, these data‐sets may be used to understand general inter‐annual, seasonal and diurnal wind patterns for the area and to assist with verification of atmospheric models. The annual wind rose for Barrow Island (75km west of Cape Preston) derived from these observations is given in Figure 2.3. These data are disaggregated into quarterly wind roses in Figures 2.4 to 2.7.

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Figure 2.3: Annual wind rose for Barrow Island derived from the years 1999 to 2005.

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Figure 2.4: Wind rose for Barrow Island for January to March from 1999 to 2005.

Figure 2.5: Wind rose for Barrow Island for April to June from 1999 to 2005.

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Figure 2.6: Wind rose for Barrow Island for July to August from 1999 to 2005.

Figure 2.7: Wind rose for Barrow Island for September to December from 1999 to 2005.

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3 METEOROLOGICAL FORCING OF THE OCEAN CURRENT MODEL

Accurate modelling of the waves and currents in any region can only be achieved with a suitable representative meteorological data set. In the past, much of the atmospheric forcing applied to drive ocean models has been based on historic, single station (wind) data obtained from the nearest automatic or manual weather station to the site of interest.

In work carried out for Woodside Energy off Northwest Cape in Australia, the limitations of adopting measured winds were clearly demonstrated. In that study, (GEMS, 2003) using satellite tracked drifting buoys, it was shown that when using coastal winds or even winds measured on site, the errors were quite large due to the fact that:

a) measured winds are only accurate at the release site;

b) as the plume drifts on the currents it moves into areas influenced by winds which are different to those at the release site; and

c) Even at the release site the currents are not just driven by the local wind but are also as a result of currents flowing into the area which are driven by different winds to those at the release site.

As a result GEMS has moved to applying spatial and time varying data from numerical weather prediction (NWP) models to force its oceanographic models.

3.1 LAPS AND MESO‐LAPS

The Bureau of Meteorology (BoM) routinely operates a suite of Numerical Weather Prediction (NWP) models at a range of spatial and temporal resolutions. These models are nested in space so that the model system captures a range of atmospheric scales ranging from global through regional (continental) to the local, or mesoscale.

The main Australian region forecast model run by the BoM is LAPS (Limited Area Prediction System) which runs on a 35km grid from halfway across the Indian Ocean to east of New Zealand. This model runs twice daily nested in the BoM global atmospheric model – GASP (Global Assimilation and Prediction model) and produces forecasts out to ten days.

The BoM has also operated its mesoscale model (MesoLAPS – Mesoscale Limited Area Prediction System) at a spatial resolution of about 10km for a period of more than seven years (since the Sydney 2000 Olympics). The model is nested inside LAPS and runs twice daily producing forecasts out to 48 hours. Meteorological data from the analysis cycle (zero hour) and the first eleven hours of forecasts of this model are now routinely downloaded twice daily and archived by GEMS. This generates a database of hourly meteorological data with the longest forecast time step of eleven hours.

Validation of the accuracy of the meteorological data for each new study area needs to be undertaken, however GEMS has determined from previous studies that the MesoLAPS model data provides a very good representation of coastal wind regimes.

Validation for this project is presented separately (GEMS, 2008A and B)

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3.2 SELECTION OF A PERIOD OF REPRESENTATIVE WINDS

In previous studies at Barrow Island it has been shown that 2001 was a “typical” period on the northwest shelf with the balance of westerly versus easterly wind events at an average level (see Figure 3.1).

For this study winds for Cape Preston were extracted from the MesoLaps database for the period 2001‐2007 and analysed to examine the inter‐annual variation in the east‐west components of the winds over the period (for winds in excess of 5 m/s). Figure 3.2 shows the relative percentage of easterlies and westerly’s over this entire period and for each individual year. In general, as expected, there is a noticeable bias towards the westerlies and the years 2001 and 2007 are the nearest to the long term average.

Accordingly, 2007 has been selected as a year broadly representative of long‐term conditions and the brine discharge simulations were commenced on January 1, 2007 and continued for 52 weeks.

Figure 3.1: Analysis of the occurrence of easterly or westerly wind events compared with the average at Barrow Island during the years 1999 to 2005.

Easterly Westerly 90 80 70 e 60 g ta n 50 e c 40 re e P 30 20 10 0 All 2001 2002 2003 2004 2005 2006 2007

Figure 3.2: Analysis of the occurrence of easterly or westerly wind events compared with the average at Cape Preston during the years 2001 to 2007.

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4. OCEANOGRAPHY

4.1 BATHYMETRY

The bathymetric data sets used in this study were derived from the GEMS database which has been developed from a range of sources including digital hydrographic chart data from Geoscience Australia. These data were updated with some local bathymetry provided by Sandwells (2007) for URS.

The bathymetry of the Cape Preston region is shown on Figure 4.1. The region can be characterised by extensive intertidal areas particularly to the south and southeast of Cape Preston and a shallow nearshore platform that extends to the southwest of Cape Preston for a few kilometres but extends to the northeast some 30 km to the vicinity of Eaglehawk Island. This platform to the east of Cape Preston is very shallow and drains Regnard Bay. It contains a number of small islands (SW and NE Regnard) and shoals. The Maitland River drains into Regnard Bay and the intertidal areas along this stretch of coast support large stands of mangrove habitat.

To the west of Cape Preston lies a shallow embayment known as Fortescue Roads. The Fortescue River discharges at the base of this embayment. The river is located some 23 km to the south‐west of Cape Preston, and is the closest river to the Cape. Both the Maitland and the Fortescue Rivers drain large areas of hinterland, but only flow occasionally in response to cyclonic downpours over the hinterland. On such occasions they discharge large volumes of fresh and highly turbid silty waters to the nearshore environment. Further to the west lies a shallow promontory on which occur a number of small islands and shoals (eg Fortescue and Steamboat Islands). This promontory runs to the north and effectively borders Fortescue Roads to the west.

Fortescue Roads drains northward into a large basin where water depths extend to ‐16 m CD. This basin is relatively flat and slopes gently from the shore out. It is partly enclosed to the north by a low subtidal ridge at ‐ 11m CD. This ridge supports a number of shoals and banks (e.g. McLennan and Cod Banks). This basin is clearly shown on Figure 5.2 (note depths are in metres) which presents detailed bathymetry recently obtained by Sandwell on behalf of CP Mining. Figure 4.2 also shows the extent of intertidal substrates in the vicinity of Cape Preston and the shallow passage to the east of Cape Preston through which the tide drains Regnard Bay.

Preston Island is located approximately 1.2 km to the north‐west of Cape Preston and is located near the tip of the shallow nearshore platform referred to earlier. At low spring tide it is barely separated from the mainland by very shallow water (< 1 m chart datum (CD)). The seabed is relatively shallow (<8 m CD) south‐west of Preston Island, however, immediately north to north west of Preston Island (~300 m offshore) the seabed drops rapidly to over 13 m CD, and deep navigable waters (>20m ) occur some 11 km to the north. Hence its suitability as a port location.

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Figure 4.1 Bathymetry of the Cape Preston region. (Note depth in fathoms).

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Figure 4.2 Cape Preston bathymetry. (Source Sandwell).

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4.2 TIDES AND CURRENTS

The dominant influence on the circulation in the waters off Cape Preston is the northwest shelf tides and the regional winds. Tides are relatively strong off Cape Preston with a typical semi‐diurnal and spring‐neap behaviour and a spring tidal range of 4.7 metres. Water movements in the region during spring tides are more influenced by tidal currents than local wind conditions. Surface current velocities during spring tides can reach 0.75 m/s (1.5 knots) whereas during neap tides the peak current velocities are typically 0.25 m/s (0.5 knots).

There is no evidence of sustained stratification in the waters off Cape Preston from the 12 months of data recorded on site (GEMS, 2008 A and B). The combination of relatively strong tidal currents, episodically strong winds producing wave action and surface currents and the relatively shallow bathymetry around Cape Preston tends to limit the opportunity for stratified layers to develop.

The majority of the flood tide reaches Cape Preston from the open ocean by going around the Montebello Islands and then flowing southwards towards the coast. When the flood tide reaches Cape Preston it splits around the Cape with flow occurring to the south‐west and to the south‐east along the coast. The ebb tide, whilst not being the exact converse of this process, generally reaches the open ocean by flowing north to north‐west around the Montebello Islands.

The dominant mixing and dispersion mechanism off Cape Preston is the strong and varying tidal currents and the episodic influence of strong surface winds.

The dominant flushing mechanism is the ebb tide which generally flows north‐north‐west from the site. The analysis of the ADCP data (GEMS, 2008A and B) also highlights a relatively strong residual current to the north‐east driven by the south‐westerly winds and the ebb tide.

Tidal forcing for the modelling study was based on data from the GEMS Australian region gridded tidal data base, which has been developed with extensive modelling programmes (primarily for AMSA Search and Rescue in Canberra).

4.3 OCEAN MODEL SETUP

The ocean currents and sea levels were modelled on two “nested” grids with GCOM3D. A large scale grid (Figure 4.3) was used to generate boundary conditions for a higher resolution GCOM3D grid (Figure 4.4). The coarse grid was run at a resolution of 1 km driven by tides and MesoLAPS winds and atmospheric pressures. The finer grid was nested in the larger grid at a resolution of 50 metres. It is necessary to run this nested system to fully capture the complex tidal dynamics of the northwest shelf region.

GCOM3D was used on this nested grid system to predict the ocean currents for the 12 months of the brine discharge simulation driven by the winds, atmospheric pressures and tides described earlier.

Examples of the ebb and flood tidal currents predicted by GCOM3D in the Cape Preston region are shown in Figures 4.5 and 4.6 respectively illustrating the fact that the dominant flushing mechanism during the dredging period is the ebb tide.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY FOR MINERALOGY Page | 21 GEMS

Figure 4.3: Northwest Shelf grid from Exmouth to Broome

Figure 4.4: Cape Preston nested grid.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 22 GEMS

Figure 4.5: Example of the ebb tide off Cape Preston predicted by GCOM3D.

Figure 4.6: Example of the flood tide off Cape Preston predicted by GCOM3D.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 23 GEMS

5. BRINE DISCHARGE MODELLING

5.1 OUTFALL SITE SELECTION

GEMS was engaged initially to assist URS/Mineralogy to select a suitable location for brine disposal which was both non‐sensitive from an environmental perspective and feasible from an engineering and economic point of view. It soon became apparent that the outfall had to be located in at least 5m depth of water at low tide to provide the initial dilution required to reduce the scale of the mixing zone.

Two sites were investigated in relatively deep (5‐10m) water to the north and east of the port (Figure 1.2). Both sites were located away from sensitive coral habitat and located over a relatively barren sandy seafloor. Location B was collocated with the CPMM brine outfall and Location C was site away from the CPMM outfall.

5.2 BRINE DISPERSION RESULTS

The Ministerial requirement is to “ensure that salinity variation resulting from the discharge is no greater than 5% above the ambient level for more than one percent of the time anywhere around Cape Preston (except within the Moderate Protection Mixing Zone.”)

This was interpreted to mean that the edge of the mixing zone is located where salinity concentrations were no greater than 5% of ambient salinity 99% of the time. Given that ambient salinity at the site is between 35 and 40 ppt, this equates to approximately 2ppt above background. Given that the brine discharge will have a concentration close to 80ppt (78.8mg/L), only 40 dilutions are required to achieve acceptable mixing.

The modelling task for this study was therefore to determine the size of this mixing zone for the two potential diffuser locations.

The hydrodynamic model GCOM3D was run for a 12 month period using data collected at Cape Preston by GEMS (2008A) during the period January to December 2007. This period has been determined by GEMS to represent a “normal” year as far as seasonal wind strength and direction are concerned.

The GEMS PLUME3D model was then used to simulate the CPMM and the Mineralogy outfalls discharging concurrently for the two potential Mineralogy outfall sites. The task was to determine the maximum area of mixing zone required for 40 dilutions to occur for 99% of the time for each of the outfalls to ensure that the mixing zone for the two outfalls working concurrently did not exceed 4Ha each.

5.2.1 OPTION 1: COLOCATED BRINE DISCHARGES

Figure 5.1 shows the location of the “double” diffuser with the Mineralogy outfall constructed as an extension to the CPMM outfall.

Figure 5.2 presents the resultant model output showing the mixing zones required to achieve 40 dilutions for 100%, 99%, and 95% of the time.

The total size of the mixing zones (for both outfalls) required to achieve 40 dilutions for this scenario are:

100% compliance: 52hA

99% compliance: 12hA

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 24 GEMS

95% compliance: 4hA

Figures 5.3 and 5.4 indicate the influence of the tidal flows on the location of the mixing zone during peak ebb and peak flood conditions. Note the instantaneous 99% mixing zone is in a southeast direction on the flood tide and a northwest direction on the ebb tide. This “bipolar” nature of the flow past the diffuser means that the overall 99% mixing zone is almost twice as big as it might be if the tides were not such a dominant force on the currents off Cape Preston. It is therefore more difficult to comply with the a specific mixing zone size in strong tidal waters than in areas where tides are weaker, even though strong tidal currents produce better dispersion because the mixing zone orients either side of the diffuser depending on whether the tide is flooding or ebbing.

Figures 5.5 and 5.6 show a random sample of the mixing zone at slack water during low neap and spring tides respectively. This situation presents the worst conditions for mixing and dispersion of the outfall because of the low water levels at low tide (particularly spring tides).

These two cases are worth considering individually. During low neap tides the water levels are below mean sea level but not at their lowest however due to the neap tides the currents are not as strong producing reduced mixing in shallower water. In the other case, during low spring tides the water levels are at their lowest but the spring tides bring strong currents which improves dispersion. In the latter case the worst situation and the best situation occur within 3 hours of each other. At low spring tide and slack water the mixing is at its worst but 3 hours later the spring tidal currents are flowing at their fastest (often greater than 1 knot) and on an increasing water level are producing the best mixing conditions.

The results are capturing all these phenomena and the overall 99% mixing zone is the result of a 12 months analysis.

5.2.2 OPTION 2: CPMM OUTFALL AT LOCATION B, MINERALOGY OUTFALL AT LOCATION C

Figure 1.2 shows the locations of the separate diffusers with the Mineralogy outfall constructed at location C and the CPMM outfall at location B.

Figure 5.7 presents the resultant model output showing the mixing zones required to achieve 40 dilutions for 100%, 99%, and 95% of the time.

The total size of the mixing zones (for each of the outfalls) for this scenario are:

Mixing Zone Compliance CPMM Outfall Mixing Zone Area Mineralogy Outfall Mixing Zone Area Percentage to achieve 40 dilutions (Ha) (Ha)

100% 15 22

99% 3.9 3.5

95% 1.5 1.2

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5.3 RESIDENCE STUDIES

To illustrate the flushing mechanisms in the region off Cape Preston a simple particle tracking exercise was undertaken to track the path of a particle randomly released at the diffuser site.

The purpose of this simulation was to investigate whether there was any likelihood of accumulation of particles or suspended salts in the region over time.

The results are shown in Figure 5.8 which show the particle track over a 5 day period from a neap to a spring tide and during a period of south‐westerly winds.

As can be seen the variation in currents in the region, and the residual flow to the north‐east found in the data analysis, basically ensures that particles or suspended salts will not accumulate in the region of the outfall or anywhere else near Cape Preston.

Figure 5.1: Proposed location of 300m long diffuser.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 26 GEMS

Figure 5.2: Mixing zone regions for 100%, 99% and 95% achievement of 40 dilutions levels for the “double” diffuser at location B.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 27 GEMS

Figure 5.3: Snapshot of the mixing zone during flood tide conditions

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 28 GEMS

Figure 5.4: Snapshot of the mixing zone during ebb tide conditions.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 29 GEMS

Figure 5.5: Snapshot of the mixing zone during low neap tides at slack water.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 30 GEMS

Figure 5.6: Snapshot of the mixing zone during low spring tides at slack water.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 31 GEMS

Figure 5.7: Percentage compliance with two 4Ha mixing zones at 100%, 99% and 95% levels for separate diffusers at locations B and C.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 32 GEMS

Figure 5.8: Track of a particle over a 5 day period after release at the diffuser site during neap tides

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 33 GEMS

6 REFERENCES

GEMS, 2008: Cape Preston Ocean Report – Volumes 1 and 2 (supplied separately)

GEMS, 2003: Vincent‐Enfield marine Study. Report to Woodside Energy. January, 2003.

SANDWELL ENGINEERING INC. April 2007. Cape Preston Iron Ore Project: at Cape Preston W.A. Bathymetric Survey at Cape Preston W.A .Report by Tara Remote Sensing Inc., Sidney B.C.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 34 GEMS

APPENDIX A: MODEL DESCRIPTIONS

A.1 GCOM3D

For studies of hydrodynamic circulation and sea level variation under ambient and extreme weather conditions, GEMS has developed the GEMS 3‐D Coastal Ocean Model (GCOM3D). GCOM3D is an advanced, fully three‐ dimensional, ocean‐circulation model that determines horizontal and vertical hydrodynamic circulation due to wind stress, atmospheric pressure gradients, astronomical tides, quadratic bottom friction and ocean thermal structure. The system will run on Windows/NT or UNIX platforms. GCOM3D is fully functional anywhere in the world using tidal constituent and bathymetric data derived from global, regional and local databases.

GCOM3D (Hubbert 1993, 1999) calculates water currents in both the horizontal and vertical planes. The model operates on a regular grid (in the x and y directions) and uses a z‐coordinate vertical‐layering scheme. That is, the depth structure is modelled using a varying number of layers, depending on the depth of water, and each layer has a constant thickness over the horizontal plane. This scheme is used to decouple surface wind stress and seabed friction and to avoid bias of current predictions for a particular layer caused by averaging of currents over varying depths, as used in sigma co‐ordinate and “depth‐averaged” model schemes. GCOM3D is also formulated as a freely scalable and relocatable model. The three‐dimensional structure of the model domain, tidal conditions at the open boundaries, and wind forcing are defined for each model application by extraction of data stored in gridded databases covering a wider geographical area of interest.

The model scale is freely adjustable, and nesting to any number of levels is supported in order to suit the hydrodynamic complexity of a study area. As the model is fully three‐dimensional, output can include current data at any or all levels in the water column. A two‐dimensional version of the model that includes tidal and flood inundation is also available for use in river systems.

GCOM3D has undergone exhaustive evaluation and verification in the 15 years it has served the coastal engineering industry in Australia and has a proven record of accurately predicting the wind and tidal driven ocean currents around the Australian continental shelf (and in many other parts of the world). The Australian National Oil Spill Response and Search and Rescue systems are based on ocean currents from GCOM3D, which has been running in real‐time at the Australian Maritime Safety Authority in Canberra for the past 2 years. It is the first real‐ time ocean prediction model in Australia. The U.S. Navy also purchased GCOM3D for its coastal ocean forecasting system.

GCOM3D has also been used in a wide range of ocean environmental studies including prediction of the fate of oil spills, sediments, hydrotest chemicals, drill cuttings, produced formation water and cooling waters as well as in other coastal ocean modelling studies such as storm surges and search and rescue.

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 35 GEMS

A.2 DISCHARGE PLUME MODELLING WITH PLUME3D

PLUME3D is a lagrangian random walk far‐field plume dispersion model which obtains oceanic conditions from GCOM3D and includes 3D plume dispersion algorithms for modelling the far‐field behaviour of a wide variety of discharge materials including sediments, sewerage, thermal discharges, oils and chemicals, accounting for processes such as dispersion and dissolution, under defined release conditions (quantity, rate etc).

Near‐field dilution of discharges is either taken from laboratory data, near‐field dilution models (such as the USA EPA models CORMIX and PLUMES) or estimated internally from algorithms which provide only an approximation to the near‐field dilution.

This model was the first 3D plume model to be used in Australia for the Geelong Ocean Outfall Study in 1984. The oil spill prediction model, OILTRAK3D, is a sub‐model of PLUME3D.

PLUME3D uses predictions from GCOM3D to provide the ocean conditions into which the discharge is released. The lagrangian nature of the model allows the discharge plume to be simulated throughout the water column taking into account the effects of natural processes such as surface waves, horizontal diffusion and dispersion. The model is free from numerical diffusion problems (such as experienced by Eulerian models) because it is not run on a grid.

The plume model can be used stochastically to simulate a large number of random events over time or can be used for specific case studies in a deterministic mode.

PLUME3D can model the behaviour of a variety of constituents within a single release volume given information on the density and other physical and chemical parameters. The model reports mass and concentration levels on the water surface, on shorelines, in the sediments or through the water column. Where multiple constituents are involved, the model can report the distribution of each constituent individually. Horizontal and vertical cross‐ sections are also available to better illustrate the three dimensional distributions

GCOM3D and PLUME3D also produce Windows and Arc‐GIS compatible graphic output that can be readily incorporated into Word documents or GIS systems (for integration with other spatial information for emergency spill response planning).

CAPE PRESTON DESALINATION PLANT BRINE DISCHARGE MODELLING STUDY ‐ MINERALOGY Page | 36 MARINE IMPACT ASSESSMENT WATER PRODUCTION DESALINATION PLANT AT CAPE PRESTON Material Data Safety Sheets - PermaCare International and Nalco Appendix D

D Material Data Safety Sheets - PermaCare International and Nalco

Prepared for International Minerals Pty Ltd, 10 September 2008 Ref: 43177570-1892 : R1337 [DK:M&C2904/PER]

MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

1. CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME : PermaTreat® PC-191

APPLICATION : REVERSE OSMOSIS ANTISCALANT

CHEMICAL DESCRIPTION : Water, Organic compound

COMPANY IDENTIFICATION : ONDEO Nalco Company ONDEO Nalco Center Naperville, Illinois 60563-1198

EMERGENCY TELEPHONE NUMBER : (800)462-5378 (24 Hours) (800) I-M-ALERT

NFPA 704M/HMIS RATING HEALTH : 0 / 1 FLAMMABILITY : 1 / 1 REACTIVITY : 0 / 0 OTHER : 0 = Insignificant 1 = Slight 2 = Moderate 3 = High 4 = Extreme

2. COMPOSITION/INFORMATION ON INGREDIENTS

Based on our hazard evaluation, none of the substances in this product are hazardous.

3. HAZARDS IDENTIFICATION

**EMERGENCY OVERVIEW**

CAUTION May cause irritation with prolonged contact. Do not get in eyes, on skin, on clothing. Do not take internally. Wear suitable protective clothing. Keep container tightly closed. Flush affected area with water. May evolve oxides of carbon (COx) under fire conditions. May evolve oxides of nitrogen (NOx) under fire conditions.

PRIMARY ROUTES OF EXPOSURE : Eye, Skin

HUMAN HEALTH HAZARDS - ACUTE :

EYE CONTACT : May cause irritation with prolonged contact.

SKIN CONTACT : May cause irritation with prolonged contact.

INGESTION : May cause gastrointestinal irritation.

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MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

INHALATION : May cause irritation of mucous membranes.

SYMPTOMS OF EXPOSURE : Acute : A review of available data does not identify any symptoms from exposure not previously mentioned. Chronic : A review of available data does not identify any symptoms from exposure not previously mentioned.

AGGRAVATION OF EXISTING CONDITIONS : A review of available data does not identify any worsening of existing conditions.

4. FIRST AID MEASURES

EYE CONTACT : Immediately flush eye with water for at least 15 minutes while holding eyelids open. If symptoms persist, call a physician.

SKIN CONTACT : Immediately flush with plenty of water for at least 15 minutes. If symptoms persist, call a physician.

INGESTION : Do not induce vomiting without medical advice. If conscious, washout mouth and give water to drink. If symptoms develop, seek medical advice.

INHALATION : Remove to fresh air, treat symptomatically. If symptoms develop, seek medical advice.

NOTE TO PHYSICIAN : Based on the individual reactions of the patient, the physician's judgement should be used to control symptoms and clinical condition.

5. FIRE FIGHTING MEASURES

FLASH POINT : None

EXTINGUISHING MEDIA : Use extinguishing media appropriate for surrounding fire. This product would not be expected to burn unless all the water is boiled away. The remaining organics may be ignitable.

FIRE AND EXPLOSION HAZARD : May evolve oxides of carbon (COx) under fire conditions. May evolve oxides of nitrogen (NOx) under fire conditions.

SPECIAL PROTECTIVE EQUIPMENT FOR FIRE FIGHTING : In case of fire, wear a full face positive-pressure self contained breathing apparatus and protective suit.

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MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

6. ACCIDENTAL RELEASE MEASURES

PERSONAL PRECAUTIONS : Restrict access to area as appropriate until clean-up operations are complete. Use personal protective equipment recommended in Section 8 (Exposure Controls/Personal Protection). Stop or reduce any leaks if it is safe to do so. Do not touch spilled material. Ventilate spill area if possible.

METHODS FOR CLEANING UP : SMALL SPILLS: Soak up spill with absorbent material. Place residues in a suitable, covered, properly labeled container. Wash affected area. LARGE SPILLS: Contain liquid using absorbent material, by digging trenches or by diking. Reclaim into recovery or salvage drums or tank truck for proper disposal. Contact an approved waste hauler for disposal of contaminated recovered material. Dispose of material in compliance with regulations indicated in Section 13 (Disposal Considerations).

ENVIRONMENTAL PRECAUTIONS : Do not contaminate surface water., Do not allow material to contaminate ground water system., Prevent material from entering sewers or waterways.

7. HANDLING AND STORAGE

HANDLING : Do not take internally. Ensure all containers are labelled. Avoid eye and skin contact. Keep the containers closed when not in use. Keep away from acids and oxidizing agents.

STORAGE CONDITIONS : Store the containers tightly closed.

8. EXPOSURE CONTROLS/PERSONAL PROTECTION

OCCUPATIONAL EXPOSURE LIMITS : This product does not contain any substance that has an established exposure limit.

ENGINEERING MEASURES : General ventilation is recommended. Local exhaust ventilation may be necessary when dusts or mists are generated.

RESPIRATORY PROTECTION : If significant mists, vapors or aerosols are generated an approved respirator is recommended.

HAND PROTECTION : Nitrile gloves, Butyl gloves, PVC gloves, Neoprene gloves

SKIN PROTECTION : Wear standard protective clothing.

EYE PROTECTION : Wear chemical splash goggles.

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MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

HYGIENE RECOMMENDATIONS : Keep a safety shower available. If clothing is contaminated, remove clothing and thoroughly wash the affected area. Launder contaminated clothing before reuse. Keep an eye wash fountain available.

HUMAN EXPOSURE CHARACTERIZATION : Based on our recommended product application and personal protective equipment, the potential human exposure is: Low

9. PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE Liquid

APPEARANCE Yellow

ODOR Ammoniacal

SPECIFIC GRAVITY 1.36 DENSITY 11.33 lb/gal SOLUBILITY IN WATER Complete pH (100 %) 10.5 OCTANOL/WATER COEFFICIENT 3.5

10. STABILITY AND REACTIVITY

STABILITY : Stable under normal conditions.

HAZARDOUS POLYMERIZATION : Hazardous polymerization will not occur.

CONDITIONS TO AVOID : Freezing temperatures.

MATERIALS TO AVOID : Strong oxidizing agents Strong acids

HAZARDOUS DECOMPOSITION PRODUCTS : Under fire conditions: Oxides of carbon, Oxides of nitrogen

11. TOXICOLOGICAL INFORMATION

The following results are for the product.

ACUTE ORAL TOXICITY : Species LD50 Tested Substance Rat > 17,800 mg/kg Product Rating : Non-Hazardous

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MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

ACUTE DERMAL TOXICITY : Species LD50 Tested Substance Rabbit > 15,800 mg/kg Product Rating : Non-Hazardous

PRIMARY SKIN IRRITATION : Draize Score Tested Substance 0.3 / 8.0 Product Rating : Practically non-irritating

PRIMARY EYE IRRITATION : Draize Score Tested Substance 3.7 / 110.0 Product Rating : Practically non-irritating

SENSITIZATION : This product is not expected to be a sensitizer.

CARCINOGENICITY : None of the substances in this product are listed as carcinogens by the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP) or the American Conference of Governmental Industrial Hygienists (ACGIH).

HUMAN HAZARD CHARACTERIZATION : Based on our hazard characterization, the potential human hazard is: Low

12. ECOLOGICAL INFORMATION

ECOTOXICOLOGICAL EFFECTS :

The following results are for the product.

ACUTE FISH RESULTS : Species Exposure LC50 Tested Substance Rainbow Trout 96 hrs > 959 mg/l Product Sheepshead Minnow 96 hrs > 1,000 mg/l Product Bluegill Sunfish 96 hrs > 300 mg/l Channel Catfish 96 hrs 1,212 mg/l Rating : Essentially non-toxic

ACUTE INVERTEBRATE RESULTS : Species Exposure LC50 EC50 Tested Substance Daphnia magna 48 hrs 863 mg/l Product Grass Shrimp 96 hrs > 1,000 mg/l Product Rating : Essentially non-toxic

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MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

AQUATIC PLANT RESULTS : Species Exposure EC50 Tested Substance Green Algae (Selenastrum 96 hrs 20 mg/l capricornutum) Rating :

AVIAN RESULTS : Species Exposure LC50 Tested Substance Bobwhite Quail 14 Days > 2,510 mg/kg

ENVIRONMENTAL HAZARD AND EXPOSURE CHARACTERIZATION Based on our hazard characterization, the potential environmental hazard is: Low Based on our recommended product application and the product's characteristics, the potential environmental exposure is: Low

If released into the environment, see CERCLA/SUPERFUND in Section 15.

13. DISPOSAL CONSIDERATIONS

If this product becomes a waste, it is not a hazardous waste as defined by the Resource Conservation and Recovery Act (RCRA) 40 CFR 261, since it does not have the characteristics of Subpart C, nor is it listed under Subpart D.

As a non-hazardous waste, it is not subject to federal regulation. Consult state or local regulation for any additional handling, treatment or disposal requirements. For disposal, contact a properly licensed waste treatment, storage, disposal or recycling facility.

14. TRANSPORT INFORMATION

The information in this section is for reference only and should not take the place of a shipping paper (bill of lading) specific to an order. Please note that the proper Shipping Name / Hazard Class may vary by packaging, properties, and mode of transportation. Typical Proper Shipping Names for this product are:

LAND TRANSPORT :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

AIR TRANSPORT (ICAO/IATA) :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

MARINE TRANSPORT (IMDG/IMO) :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

ONDEO Nalco Company ONDEO Nalco Center • Naperville, Illinois 60563-1198 (630)305-1000 6 / 9

MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

15. REGULATORY INFORMATION

NATIONAL REGULATIONS, USA :

OSHA HAZARD COMMUNICATION RULE, 29 CFR 1910.1200 : Based on our hazard evaluation, none of the substances in this product are hazardous.

CERCLA/SUPERFUND, 40 CFR 117, 302 : Notification of spills of this product is not required.

SARA/SUPERFUND AMENDMENTS AND REAUTHORIZATION ACT OF 1986 (TITLE III) - SECTIONS 302, 311, 312, AND 313 :

SECTION 302 - EXTREMELY HAZARDOUS SUBSTANCES (40 CFR 355) : This product does not contain substances listed in Appendix A and B as an Extremely Hazardous Substance.

SECTIONS 311 AND 312 - MATERIAL SAFETY DATA SHEET REQUIREMENTS (40 CFR 370) : Our hazard evaluation has found that this product is not hazardous under 29 CFR 1910.1200.

Under SARA 311 and 312, the EPA has established threshold quantities for the reporting of hazardous chemicals. The current thresholds are: 500 pounds or the threshold planning quantity (TPQ), whichever is lower, for extremely hazardous substances and 10,000 pounds for all other hazardous chemicals.

SECTION 313 - LIST OF TOXIC CHEMICALS (40 CFR 372) : This product does not contain substances on the List of Toxic Chemicals.

TOXIC SUBSTANCES CONTROL ACT (TSCA) : The chemical substances in this product are on the TSCA 8(b) Inventory (40 CFR 710).

NSF INTERNATIONAL : This product has received NSF/International certification under ANSI/NSF Standard 60 in the reverse osmosis antiscalant category. The official name is "Miscellaneous Water Supply Products." Maximum product application dosage is : 5 mg/l. Only product manufactured at NDT plant at Chagrin Falls, OH, and whose container label bears the ANSI/NSF Mark may be used in potable water treatment applications.

FEDERAL WATER POLLUTION CONTROL ACT, CLEAN WATER ACT, 40 CFR 401.15 / formerly Sec. 307, 40 CFR / formerly Sec. 311 : None of the substances are specifically listed in the regulation.

CLEAN AIR ACT, Sec. 111 (40 CFR 60, Volatile Organic Compounds), Sec. 112 (40 CFR 61, Hazardous Air Pollutants), Sec. 602 (40 CFR 82, Class I and II Ozone Depleting Substances) : None of the substances are specifically listed in the regulation.

CALIFORNIA PROPOSITION 65 : This product does not contain substances which require warning under California Proposition 65.

MICHIGAN CRITICAL MATERIALS : None of the substances are specifically listed in the regulation.

ONDEO Nalco Company ONDEO Nalco Center • Naperville, Illinois 60563-1198 (630)305-1000 7 / 9

MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

STATE RIGHT TO KNOW LAWS : None of the substances are specifically listed in the regulation.

NATIONAL REGULATIONS, CANADA :

WORKPLACE HAZARDOUS MATERIALS INFORMATION SYSTEM (WHMIS) : This product has been classified in accordance with the hazard criteria of the Controlled Products Regulations (CPR) and the MSDS contains all the information required by the CPR.

WHMIS CLASSIFICATION : Not considered a WHMIS controlled product.

CANADIAN ENVIRONMENTAL PROTECTION ACT (CEPA) : All substances in this product are listed on the Domestic Substances List (DSL), are exempt, or have been reported in accordance with the New Substances Notification Regulations.

16. OTHER INFORMATION

Due to our commitment to Product Stewardship, we have evaluated the human and environmental hazards and exposures of this product. Based on our recommended use of this product, we have characterized the product's general risk. This information should provide assistance for your own risk management practices. We have evaluated our product's risk as follows:

* The human risk is: Low

* The environmental risk is: Low

Any use inconsistent with our recommendations may affect the risk characterization. Our sales representative will assist you to determine if your product application is consistent with our recommendations. Together we can implement an appropriate risk management process.

This product material safety data sheet provides health and safety information. The product is to be used in applications consistent with our product literature. Individuals handling this product should be informed of the recommended safety precautions and should have access to this information. For any other uses, exposures should be evaluated so that appropriate handling practices and training programs can be established to insure safe workplace operations. Please consult your local sales representative for any further information.

REFERENCES

Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices, American Conference of Governmental Industrial Hygienists, OH., (Ariel Insight# CD-ROM Version), Ariel Research Corp., Bethesda, MD.

Hazardous Substances Data Bank, National Library of Medicine, Bethesda, Maryland (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, Co.

IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man, Geneva: World Health Organization, International Agency for Research on Cancer.

ONDEO Nalco Company ONDEO Nalco Center • Naperville, Illinois 60563-1198 (630)305-1000 8 / 9

MATERIAL SAFETY DATA SHEET PRODUCT

PermaTreat® PC-191

EMERGENCY TELEPHONE NUMBER (800)462-5378 (24 Hours) (800) I-M-ALERT

Integrated Risk Information System, U.S. Environmental Protection Agency, Washington, D.C. (TOMES CPS# CD- ROM Version), Micromedex, Inc., Englewood, CO.

Annual Report on Carcinogens, National Toxicology Program, U.S. Department of Health and Human Services, Public Health Service.

Title 29 Code of Federal Regulations, Part 1910, Subpart Z, Toxic and Hazardous Substances, Occupational Safety and Health Administration (OSHA), (Ariel Insight# CD-ROM Version), Ariel Research Corp., Bethesda MD.

Registry of Toxic Effects of Chemical Substances, National Institute for Occupational Safety and Health, Cincinnati, OH, (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, CO.

Ariel Insight# (An integrated guide to industrial chemicals covered under major regulatory and advisory programs), North American Module, Western European Module, Chemical Inventories Module and the Generics Module (Ariel Insight# CD-ROM Version), Ariel Research Corp., Bethesda, MD.

The Teratogen Information System, University of Washington, Seattle, WA (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, CO

Prepared By : Product Safety Department Date issued : 09/13/2000 Replaces : 08/30/2000

ONDEO Nalco Company ONDEO Nalco Center • Naperville, Illinois 60563-1198 (630)305-1000 9 / 9

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

1. CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME : NALCO 8103 PLUS

APPLICATION : WATER TREATMENTWATER CLARIFICATION AID

COMPANY IDENTIFICATION : Nalco Company 1601 W. Diehl Road Naperville, Illinois 60563-1198

EMERGENCY TELEPHONE NUMBER(S) : (800) 424-9300 (24 Hours) CHEMTREC

NFPA 704M/HMIS RATING HEALTH : 0 / 1 FLAMMABILITY : 0 / 1 INSTABILITY : 0 / 0 OTHER : 0 = Insignificant 1 = Slight 2 = Moderate 3 = High 4 = Extreme

2. COMPOSITION/INFORMATION ON INGREDIENTS

Based on our hazard evaluation, none of the substances in this product are hazardous.

3. HAZARDS IDENTIFICATION

**EMERGENCY OVERVIEW**

CAUTION May cause irritation with prolonged contact. Do not get in eyes, on skin, on clothing. Do not take internally. Use with adequate ventilation. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. After contact with skin, wash immediately with plenty of water. Wear suitable protective clothing. May evolve oxides of carbon (COx) under fire conditions. May evolve oxides of nitrogen (NOx) under fire conditions. May evolve ammonia (NH4) under fire conditions. May evolve HCl under fire conditions.

PRIMARY ROUTES OF EXPOSURE : Eye, Skin

HUMAN HEALTH HAZARDS - ACUTE :

EYE CONTACT : May cause irritation with prolonged contact.

SKIN CONTACT : May cause irritation with prolonged contact.

INGESTION : Not a likely route of exposure. No adverse effects expected.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 1 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

INHALATION : Not a likely route of exposure. No adverse effects expected.

AGGRAVATION OF EXISTING CONDITIONS : A review of available data does not identify any worsening of existing conditions.

4. FIRST AID MEASURES

EYE CONTACT : Flush affected area with water. If symptoms develop, seek medical advice.

SKIN CONTACT : Remove contaminated clothing. Wash off affected area immediately with plenty of water. If symptoms develop, seek medical advice.

INGESTION : Do not induce vomiting without medical advice. If conscious, washout mouth and give water to drink. If symptoms develop, seek medical advice.

INHALATION : Remove to fresh air, treat symptomatically. If symptoms develop, seek medical advice.

If Swallowed: Do not induce vomiting. Drink large quantities of water. Never give anything by mouth to an unconscious or convulsing person.

If in Eyes: Flood eyes with water for at least 15 minutes.

If on Skin: Wash thoroughly soap and water.

NOTE TO PHYSICIAN : Based on the individual reactions of the patient, the physician's judgement should be used to control symptoms and clinical condition.

5. FIRE FIGHTING MEASURES

FLASH POINT : Not flammable

EXTINGUISHING MEDIA : This product would not be expected to burn unless all the water is boiled away. The remaining organics may be ignitable. Use extinguishing media appropriate for surrounding fire. Water mist may be used to cool closed containers.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 2 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

FIRE AND EXPLOSION HAZARD : May evolve oxides of carbon (COx) under fire conditions. May evolve oxides of nitrogen (NOx) under fire conditions. May evolve ammonia (NH4) under fire conditions. May evolve HCl under fire conditions.

SPECIAL PROTECTIVE EQUIPMENT FOR FIRE FIGHTING : In case of fire, wear a full face positive-pressure self contained breathing apparatus and protective suit.

6. ACCIDENTAL RELEASE MEASURES

PERSONAL PRECAUTIONS : Notify appropriate government, occupational health and safety and environmental authorities. Do not touch spilled material. Stop or reduce any leaks if it is safe to do so. Use personal protective equipment recommended in Section 8 (Exposure Controls/Personal Protection).

ENVIRONMENTAL PRECAUTIONS : This product is toxic to fish. It should not be directly discharged into lakes, ponds, streams, waterways or public water supplies.

7. HANDLING AND STORAGE

HANDLING : Do not take internally. Have emergency equipment (for fires, spills, leaks, etc.) readily available. Ensure all containers are labelled. Avoid eye and skin contact.

STORAGE CONDITIONS : Store separately from oxidizers. Store the containers tightly closed. Protect product from freezing.

SUITABLE CONSTRUCTION MATERIAL : HDPE (high density polyethylene), Compatibility with Plastic Materials can vary; we therefore recommend that compatibility is tested prior to use.

8. EXPOSURE CONTROLS/PERSONAL PROTECTION

OCCUPATIONAL EXPOSURE LIMITS : This product does not contain any substance that has an established exposure limit.

ENGINEERING MEASURES : General ventilation is recommended.

RESPIRATORY PROTECTION : Respiratory protection is not normally needed.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 3 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

HAND PROTECTION : Nitrile gloves, PVC gloves

SKIN PROTECTION : Wear standard protective clothing.

EYE PROTECTION : Wear chemical splash goggles.

HYGIENE RECOMMENDATIONS : Keep an eye wash fountain available. Keep a safety shower available.

9. PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE Viscous liquid

APPEARANCE Clear Yellow

ODOR None

SPECIFIC GRAVITY 1.018 - 1.058 @ 77 °F / 25 °C DENSITY 8.5 - 8.81 lb/gal SOLUBILITY IN WATER Complete pH (100 %) 5.0 - 8.0 VISCOSITY < 1,050 cps @ 77 °F / 25 °C FREEZING POINT 14 °F / -9.9 °C BOILING POINT > 212 °F / > 100 °C VAPOR PRESSURE Same as water VAPOR DENSITY Same as water VOC CONTENT 0.00 % EPA Method 24

Note: These physical properties are typical values for this product and are subject to change.

10. STABILITY AND REACTIVITY

STABILITY : Stable under normal conditions.

HAZARDOUS POLYMERIZATION : Hazardous polymerization will not occur.

CONDITIONS TO AVOID : Freezing temperatures.

MATERIALS TO AVOID : Contact with strong oxidizers (e.g. chlorine, peroxides, chromates, nitric acid, perchlorate, concentrated oxygen, permanganate) may generate heat, fires, explosions and/or toxic vapors.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 4 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

HAZARDOUS DECOMPOSITION PRODUCTS : Under fire conditions: Oxides of carbon, Oxides of nitrogen, May evolve ammonia (NH4) under fire conditions., HCl

11. TOXICOLOGICAL INFORMATION

The following results are for the polymer.

ACUTE ORAL TOXICITY : Species LD50 Test Descriptor Rat 25,500 mg/kg Similar Product Rating : Non-Hazardous

ACUTE DERMAL TOXICITY : Species LD50 Test Descriptor Rabbit > 20,000 mg/kg 40% Active Ingredient Rating : Non-Hazardous

PRIMARY SKIN IRRITATION : Draize Score Test Descriptor 1.0 / 8.0 Similar Product Rating : Slightly irritating

PRIMARY EYE IRRITATION : Draize Score Test Descriptor 8 / 110.0 Similar Product Rating : Practically non-irritating

SENSITIZATION : This product is not expected to be a sensitizer.

12. ECOLOGICAL INFORMATION

ECOTOXICOLOGICAL EFFECTS :

No toxicity studies have been conducted on this product.

ACUTE FISH RESULTS : Species Exposure LC50 Test Descriptor Rainbow Trout 96 hrs 0.85 mg/l Product tested in clean water Inland Silverside 96 hrs > 5,000 mg/l Product tested in clean water Zebra Danio 96 hrs 10 - 100 mg/l Representative polymer tested in water with

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 5 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

DOC Fathead Minnow 96 hrs 3.29 mg/l Product

ACUTE INVERTEBRATE RESULTS : Species Exposure LC50 EC50 Test Descriptor Daphnia magna 48 hrs 2.06 mg/l Product tested in clean water Ceriodaphnia dubia 48 hrs 1.09 mg/l Similar product tested in clean water Ceriodaphnia dubia 48 hrs 2.5 mg/l Product tested in clean water Daphnia magna 48 hrs 10 - 100 mg/l Representative polymer tested in water with DOC

CHRONIC INVERTEBRATE RESULTS : Species Test Type NOEC / LOEC End Point Test Descriptor Ceriodaphnia dubia 3 Brood 1.25 mg/l / 2.5 mg/l Reproduction Product

ADDITIONAL ECOLOGICAL DATA: NOEC on earthworm: > 1000 mg/l (representative polymer) AOX information: Product contains no organic halogens.

MOBILITY : The environmental fate was estimated using a level III fugacity model embedded in the EPI (estimation program interface) Suite TM , provided by the US EPA. The model assumes a steady state condition between the total input and output. The level III model does not require equilibrium between the defined media. The information provided is intended to give the user a general estimate of the environmental fate of this product under the defined conditions of the models. If released into the environment this material is expected to distribute to the air, water and soil/sediment in the approximate respective percentages;

Air Water Soil/Sediment <5% 30 - 50% 50 - 70%

The portion in water is expected to be soluble or dispersible.

BIOACCUMULATION POTENTIAL This preparation or material is not expected to bioaccumulate.

OTHER INFORMATION The hazard characterization is based on the tests or potential hazard in the clean water.

If released into the environment, see CERCLA/SUPERFUND in Section 15.

13. DISPOSAL CONSIDERATIONS

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 6 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

14. TRANSPORT INFORMATION

LAND TRANSPORT :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

AIR TRANSPORT (ICAO/IATA) :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

MARINE TRANSPORT (IMDG/IMO) :

Proper Shipping Name : PRODUCT IS NOT REGULATED DURING TRANSPORTATION

15. REGULATORY INFORMATION

NATIONAL REGULATIONS, USA :

OSHA HAZARD COMMUNICATION RULE, 29 CFR 1910.1200 : Based on our hazard evaluation, none of the substances in this product are hazardous.

CERCLA/SUPERFUND, 40 CFR 117, 302 : Notification of spills of this product is not required.

SARA/SUPERFUND AMENDMENTS AND REAUTHORIZATION ACT OF 1986 (TITLE III) - SECTIONS 302, 311, 312, AND 313 :

SECTION 302 - EXTREMELY HAZARDOUS SUBSTANCES (40 CFR 355) : This product does not contain substances listed in Appendix A and B as an Extremely Hazardous Substance.

SECTIONS 311 AND 312 - MATERIAL SAFETY DATA SHEET REQUIREMENTS (40 CFR 370) : Our hazard evaluation has found that this product is not hazardous under 29 CFR 1910.1200.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 7 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

SECTION 313 - LIST OF TOXIC CHEMICALS (40 CFR 372) : This product does not contain substances on the List of Toxic Chemicals.

TOXIC SUBSTANCES CONTROL ACT (TSCA) : The substances in this preparation are included on or exempted from the TSCA 8(b) Inventory (40 CFR 710)

FOOD AND DRUG ADMINISTRATION (FDA) Federal Food, Drug and Cosmetic Act : When use situations necessitate compliance with FDA regulations, this product is acceptable under : 21 CFR 176.170 Components of paper and paperboard in contact with aqueous and fatty foods and 21 CFR 176.180 Components of paper and paperboard in contact with dry foods.

1) As a flocculant employed prior to the sheet-forming operation in the manufacture of paper and paperboard and used at a level not to exceed 10 mg/L (10 ppm) of influent water. 2) As a pigment dispersant and/or retention aid prior to the sheet-forming operation at a level not to exceed 10 pounds of active polymer per ton of finished paper and paperboard with the level of residual monomer not to exceed 1 weight percent of the polymer (dry basis). 3) As a pigment dispersant in coatings at a level not to exceed 3.5 pounds of active polymer per ton of finished paper and paperboard.

This product has been certified as KOSHER/PAREVE for year-round use INCLUDING THE PASSOVER SEASON by the CHICAGO RABBINICAL COUNCIL.

NSF INTERNATIONAL : This product has received NSF/International certification under NSF/ANSI Standard 60 in the coagulation and flocculation category. The official name is "Poly (Diallyldimethylammonium Chloride) (pDADMAC)." Maximum product application dosage is : 57 mg/l.

FEDERAL WATER POLLUTION CONTROL ACT, CLEAN WATER ACT, 40 CFR 401.15 / formerly Sec. 307, 40 CFR 116.4 / formerly Sec. 311 : None of the substances are specifically listed in the regulation.

CALIFORNIA PROPOSITION 65 : This product does not contain substances which require warning under California Proposition 65.

MICHIGAN CRITICAL MATERIALS : None of the substances are specifically listed in the regulation.

STATE RIGHT TO KNOW LAWS : None of the substances are specifically listed in the regulation.

NATIONAL REGULATIONS, CANADA :

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 8 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

WHMIS CLASSIFICATION : Not considered a WHMIS controlled product.

CANADIAN ENVIRONMENTAL PROTECTION ACT (CEPA) : The substances in this preparation are listed on the Domestic Substances List (DSL), are exempt, or have been reported in accordance with the New Substances Notification Regulations.

INTERNATIONAL CHEMICAL CONTROL LAWS

AUSTRALIA All substances in this product comply with the National Industrial Chemicals Notification & Assessment Scheme (NICNAS).

EUROPE The substances in this preparation have been reviewed for compliance with the EINECS or ELINCS inventories.

KOREA All substances in this product comply with the Toxic Chemical Control Law (TCCL) and are listed on the Existing Chemicals List (ECL)

16. OTHER INFORMATION

REFERENCES

Hazardous Substances Data Bank, National Library of Medicine, Bethesda, Maryland (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, CO.

IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man, Geneva: World Health Organization, International Agency for Research on Cancer.

Integrated Risk Information System, U.S. Environmental Protection Agency, Washington, D.C. (TOMES CPS# CD- ROM Version), Micromedex, Inc., Englewood, CO.

Annual Report on Carcinogens, National Toxicology Program, U.S. Department of Health and Human Services, Public Health Service.

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 9 / 10

MATERIAL SAFETY DATA SHEET PRODUCT

NALCO 8103 PLUS

EMERGENCY TELEPHONE NUMBER(S) (800) 424-9300 (24 Hours) CHEMTREC

Registry of Toxic Effects of Chemical Substances, National Institute for Occupational Safety and Health, Cincinnati, OH, (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, CO.

The Teratogen Information System, University of Washington, Seattle, WA (TOMES CPS# CD-ROM Version), Micromedex, Inc., Englewood, CO.

Prepared By : Product Safety Department Date issued : 07/14/2005 Version Number : 4.5

Nalco Company 1601 W. Diehl Road • Naperville, Illinois 60563-1198 • (630)305-1000 For additional copies of an MSDS visit www.nalco.com and request access 10 / 10

International Minerals Pty. Ltd.

Level 4, 5 Mill Street

Perth WA 6000