Balmoral South Iron Ore Project PER - Task 1 A
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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 Prepared for International Minerals Pty Ltd, 10 September 2008 Ref: 43177570-1892 : R1337 [DK:M&C2904/PER] 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.....................................................................................