Stream Sediment and Morphology Assessment

Transcription

1 Appendix D Stream Sediment and Morphology Assessment Environmental Management Plan D May 2014

2

3 Colton Coal Project Stream Sediment and Morphology Report Prepared for: Northern Energy Corporation Ltd June 2010

4 Document History and Status Issue Rev. Issued To Qty Date Reviewed Approved 1 0 NEC NEC GB Author: Project Manager: Name of Client : Name of Project: Title of Document: Document Version: Amy Creighton Gareth Bramston Northern Energy Corporation Ltd Colton Coal Project Stream Sediment and Morphology Final This controlled document is the property of AustralAsian Resource Consultants Pty Ltd and all rights are reserved in respect of it. This document may not be reproduced or disclosed in any manner whatsoever, in whole or in part, without the prior written consent of AustralAsian Resource Consultants Pty Ltd. AustralAsian Resource Consultants Pty Ltd expressly disclaims any responsibility for or liability arising from the use of this document by any third party. Stream Sediment & Morphology Report i June 2010

5 TABLE OF CONTENTS 1.0 INTRODUCTION SCOPE OF STUDY PROJECT AND SITE DESCRIPTION PROJECT SUMMARY PROJECT LOCATION CLIMATE LOCAL AND REGIONAL WATER RESOURCES METHODOLOGY STREAM MORPHOLOGY STREAM SEDIMENTS SURFACE WATER QUALITY RESULTS AND DISCUSSION STREAM MORPHOLOGY SW SW SW SW Summary of Stream Morphology STREAM SEDIMENTS Particle Size Distribution Stream Sediment Metal Concentrations SURFACE WATER QUALITY CONCLUSIONS AND RECOMMENDATIONS STREAM MORPHOLOGY STREAM SEDIMENTS WATER QUALITY RECOMMENDATIONS REFERENCES LIST OF FIGURES Figure 1: Regional Location Plan... 3 Figure 2: Climate Data for Maryborough... 4 Figure 3: Mary River Drainage Basin... 5 Figure 4: Location of Local Watercourses... 6 Figure 5: Waterways within the Colton MLA... 7 Figure 6: Method of Determining Stream Order... 8 Figure 7: Surface Water and Stream Sediment Sampling Sites Stream Sediment & Morphology Report ii June 2010

6 LIST OF TABLES Table 1: ANZECC (2000) Stream Sediment Trigger Limits Table 2: ANZECC (2000) Trigger Limits for Water Quality Table 3: Particle Size Analysis Table 4: Stream Sediment Quality Results Table 5: Water Quality Results LIST OF PHOTO PLATES Photo Plate 1: Surface water monitoring SW1 following a significant rainfall event (July, 2008).. 16 Photo Plate 2: Surface water monitoring SW2 following a significant rainfall event (July, 2008).. 17 Photo Plate 3: Surface water monitoring SW3 following a significant rainfall event (July, 2008).. 18 Photo Plate 4: Surface water monitoring SW4 (Established January, 2010) LIST OF APPENDICES Appendix A: Stream Sediment Data Appendix B: Water Quality Data A B Stream Sediment & Morphology Report iii June 2010

7 LIST OF ABBREVIATIONS ºC - Degrees Celsius AARC - AustralAsian Resource Consultants Pty Ltd ANZECC - Australian and New Zealand Environment and Conservation Council AURIVAS - Australian River Assessment System EPC - Exploration Permit for Coal GPS - Global Positioning System ha - hectare(s) km - kilometre(s) m - metre(s) MLA - Mining Lease Application mm - millimetres NATA - National Association of Testing Authorities NEC - Northern Energy Corporation Ltd ROM - Run of Mine Stream Sediment & Morphology Report iv June 2010

8 1.0 INTRODUCTION AustralAsian Resource Consultants Pty Ltd (AARC) was commissioned by Northern Energy Corporation Ltd (NEC) to undertake a baseline Stream Sediment and Morphology survey for a Mining Lease Application (MLA) for the Colton Coal Project (the Project). 1.1 SCOPE OF STUDY This study involves describing watercourses and their quality in the area affected by the Project with an outline of the significance of these waters to the river catchment system in which they occur. An assessment has been undertaken of existing water quality in watercourses likely to be affected by the Project. The basis for this assessment was a desktop review of local drainage patterns, and four site visits to collect data from sampling stations located on and downstream of the Project. This report provides a description of the pre-mining condition of watercourses potentially affected by the Project, including: Stream morphology characteristics; Stream sediment quality; and Water quality; All monitoring and interpretation was undertaken in a manner consistent with the Australian and New Zealand Environment Conservation Council (ANZECC) Guidelines (2000), and the Queensland Water Quality Guidelines (2009). Recommendations have been made to minimise impacts of the Project on watercourses both on the MLA and downstream. Development of site specific reference data for water quality and implementation of a comprehensive monitoring program are discussed in detail. Stream Sediment & Morphology Report 1 June 2010

9 2.0 PROJECT AND SITE DESCRIPTION 2.1 PROJECT SUMMARY The Project proposes open cut mining of the Burrum Coal Measures of the Maryborough Basin, in southeast Queensland. The Project site MLA covers approximately 1,024 hectares (ha) and is located within Exploration Permit for Coal (EPC) 923 and EPC Mining of up to 1,000,000 tonnes per annum (tpa) of Run of Mine (ROM) coking coal is proposed for an expected mine life of 8-10 years (approximately 5 million tonne total resource). The Project includes construction and operation of a modular Coal Processing Plant with capacity for 200 tonnes per an hour throughput of coal. Product coal is to be stockpiled on site before train loading and rail to the Port of Gladstone. Vehicle access to the Project MLA will be on existing roads. 2.2 PROJECT LOCATION The Project site is located in southern Queensland, approximately 15 kilometres (km) north of Maryborough. The proposed site is approximately 20 km inland and 230 km north of Brisbane, as shown in Figure 1. Access to the Project site is via the Churchill Mine Road which connects to the Maryborough Hervey Bay Road. Stream Sediment & Morphology Report 2 June 2010

10 Figure 1: Regional Location Plan Stream Sediment & Morphology Report 3 June 2010

11 Degree C mm 2.3 CLIMATE Information from the Bureau of Meteorology ( depicted in Figure 2, indicates that the average annual rainfall for the region (based on data for the Maryborough weather station) is approximately 1152 millimetres (mm). Rainfall is typically seasonal, with the dry season peaking from July to September (average 45.3 mm per month) and the wet season peaking between December and March (average mm per month). The coldest period of the year occurs in July (average minimum 8.6 degrees Celsius (ºC), average maximum 22.0 ºC) and the warmest month of the year is January (average minimum 20.6 ºC, average maximum 30.7 ºC). Mean Temperature & Rainfall for Maryborough January February Australian Government Bureau of Meteorology Website 2008 Figure 2: March April May June July August September October November December Climate Data for Maryborough Maximum temp Minimum temp Rainfall (mm) 2.4 LOCAL AND REGIONAL WATER RESOURCES The Project site is located within the Mary River Drainage Basin which flows in an easterly direction to the Pacific Ocean. The Mary River Drainage Basin is shown in Figure 3 below 1. 1 Sourced from Mary Basin Wetland Summary Information ( Stream Sediment & Morphology Report 4 June 2010

12 Figure 3: Mary River Drainage Basin Several small unnamed waterways flow east off the Project site, converge and drain into the Susan River approximately 8 km downstream. The Susan River meanders east and empties into the Great Sandy Straight at the mouth of the Mary River, approximately 20km from the Project site. Saltwater Creek, situated approximately 4 km south of the Project site, flows into the Mary River approximately 25 km from the mouth of the Mary River (Figure 4). Stream Sediment & Morphology Report 5 June 2010

13 Figure 4: Location of Local Watercourses The flows of the minor ephemeral creeks on the Project site are restricted to heavy rainfall events, which occur throughout the year, but most frequently between the months of December and March (wet season). Figure 5 details the location of waterways within the proposed MLA. Surface water on the site is not a source of water for human consumption or livestock / agriculture, however downstream water usage may include these facets. Stream Sediment & Morphology Report 6 June 2010

14 Figure 5: Waterways within the Colton MLA Stream Sediment & Morphology Report 7 June 2010

15 3.0 METHODOLOGY 3.1 STREAM MORPHOLOGY Baseline data on the geomorphology of waterways on the Project site was collected in four separate surveys: A wet season survey from 21 st - 29 th April 2008; Water sample collection following rainfall on 25 th July 2008; A dry season survey from 11 th 18 th August; An additional wet season survey on the 21 st January 2010; and Water sample collection following rainfall on 26 th March, The morphological assessment was based on relevant sections of the Australian Rivers Assessment System (AUSRIVAS). A hierarchical ordering system was used (Conrick and Cockayne 2001) to classify streams on the Project site. A second order stream is formed by the joining of two first order streams, the junction of two second order streams forms a third order stream, and so on. This system is illustrated in Figure 6. Figure 6: Method of Determining Stream Order The locations of the survey sample sites surface water and stream sediments are shown in Figure 7 below. Site selection was based on stream characteristics such as channel dimensions, potential for flow, flow capacity, flow direction across the site and stream order. A selection of sampling sites provides baseline data of the morphology / quality of the waterway on the Project site and immediately downstream. Water quality and stream sediment data will allow for comparison with future monitoring programs that target potential mining impacts. During the Stream Sediment & Morphology Report 8 June 2010

16 commissioning stage of the Project, an ongoing monitoring program will be implemented based on the recommendations of this report. Stream Sediment & Morphology Report 9 June 2010

17 Figure 7: Surface Water and Stream Sediment Sampling Sites Stream Sediment & Morphology Report 10 June 2010

18 Morphology data was collected from sample sites by taking cross-sections of the waterways. At each cross-section, the following was noted: Depth of channel; Width of channel; Slope of banks; Stability of banks; Stream substrate type including obtaining a sediment sample; Details of water (if present) including colour, depth and a sample; Details of terracing and flood plains if present; Overhangs; Debris and tree roots; and Vegetation either within the channel or on the banks (i.e. the surrounding vegetation). In addition, photographs of each water channel cross-section were taken from locations which were documented by Global Positioning System (GPS) coordinates. This will allow direct comparison between this survey and any future monitoring surveys. 3.2 STREAM SEDIMENTS At each of the stream morphology description sites, a sediment sample of 200 grams was collected every 5 metres (m) along a 50 m transect and placed into a clean bucket. The sediment samples in the bucket were then thoroughly mixed together and a composite sample was taken. The sediment samples were then sent to Australian Laboratory Services, a National Association of Testing Authorities (NATA) accredited laboratory, to be analysed for comparison to the following parameters: Stream Sediment & Morphology Report 11 June 2010

19 Table 1: ANZECC (2000) Stream Sediment Trigger Limits Parameter ANZECC (2000) Stream Sediment (low) Triggers ANZECC (2000) Stream Sediment (high) Triggers Cadmium (Cd) (mg/kg) Chromium (Cr) (mg/kg) Copper (Cu) (mg/kg) Mercury (Hg) (mg/kg) Silver (Ag) (mg/kg) Nickel (Ni) (mg/kg) Lead (Pb) (mg/kg) Antimony (Sb) (mg/kg) Arsenic (As) (mg/kg) Zinc (Zn) (mg/kg Particle Size Analysis (% gravel, sand, silt and clay) - - Particle size analysis allows for future comparison of monitoring results as a significant difference in distribution of particle sizes in sediment samples can distort comparisons of metal concentrations from one site to another. The particle size analysis was analysed as percentages of gravel, sand, silt and clay. 3.3 SURFACE WATER QUALITY A relevant range of physical and chemical parameters has been measured to gauge the potential environmental harm of the Project on any affected watercourse. The collection of background water quality data to aid in determining water quality trigger limits for the Project has been conducted as proposed by the ANZECC (2000) Guidelines. Trigger levels are based on 95% species protection levels. Surface water samples were collected from sites SW1, SW2 and SW3 following rainfall in July No water has been available for sampling at SW4 since the sites establishment in January Samples were immediately refrigerated and sent to a NATA accredited lab for analysis and the results were compared to ANZECC (2000) Guidelines for both Aquatic Ecosystems and Livestock Drinking Water, as shown in Table 2. The results were also compared to data collected from Saltwater Creek in July 2008, and historical data from the Mary River (data ranges from 1975 to 2008), approximately 100 m upstream of the mouth of Saltwater Creek. Stream Sediment & Morphology Report 12 June 2010

20 Table 2: ANZECC (2000) Trigger Limits for Water Quality Parameter ANZECC (2000) Aquatic Ecosystems ANZECC (2000) Livestock Drinking Water Conductivity (EC) at 25ºC (us/cm) n/a ph (ph units) n/a Total Alkalinity as CaCO3 (mg/l) n/a n/a Total Dissolved Solids (mg/l) n/a 4000 Total Suspended Solids n/a n/a Calcium as Ca soluble (mg/l) n/a 1000 Chloride as Cl- (mg/l) n/a n/a Magnesium as Mg soluble (mg/l) n/a n/a Potassium as K soluble (mg/l) n/a n/a Sodium as Na soluble (mg/l) n/a n/a Sulphate as SO4 (mg/l) n/a 1000 Aluminium as Total Al (mg/l) Arsenic as Total As (mg/l) Boron as Total B (mg/l) Copper as Total Cu (mg/l) Cadmium as Total Cd (mg/l) Chromium as Total Cr (mg/l) Cobalt as Total Co (mg/l) n/a 1.0 Iron as Total Fe (mg/l) n/a n/a Lead as Total Pb (mg/l) Stream Sediment & Morphology Report 13 June 2010

21 Parameter ANZECC (2000) Aquatic Ecosystems ANZECC (2000) Livestock Drinking Water Manganese as Total Mn (mg/l) 1.9 n/a Nickel as Total Ni (mg/l) Selenium as Total Se (mg/l) Zinc as Total Zn (mg/l) Stream Sediment & Morphology Report 14 June 2010

22 4.0 RESULTS AND DISCUSSION 4.1 STREAM MORPHOLOGY Three small, unnamed waterways exist on the Project Site. These watercourses are 1 st order streams and cross the MLA in several locations as shown in Figure 5. The Department of Environment and Resources Management (DERM) have confirmed that the waterways present do not constitute watercourses as defined by the Water Act Monitoring locations SW1, SW2 and SW3 are situated on a single drainage line crossing the MLA. This stream is characterised by a small channel, defined only in places and for the most part without obvious banks. Large sections of the stream appear as low lying ground occasionally inundated in times of surface water flow. The surrounding landscape gradually changes to gently undulating higher ground. Location SW4 is situated on a separate drainage line in the northern corner of the MLA. This drainage line displays similar characteristics to those detailed above, without obvious banks and sections of largely undefined channel SW1 Location Located upstream of the proposed mine and infrastructure, near the northern boundary of the MLA (Figure 7). Co-ordinates , (MGA 94, Zone 56) Channel Depth Channel Width Flow Direction Bank Slope Stability Substrate Terracing Water No distinct channel No distinct channel South-east No bank obvious High, vegetation cover and lack of defined bank provides good stability. Greyish brown fine sandy loam None 0.2 m depth over 20 m width Debris and Tree Roots No clear channel defined. Numerous trees and significant groundcover within the waterway. Flood Plain Riparian Vegetation Floodplain is not clearly defined and could extend to approximately 50 m total width in times of high rainfall. Dominated by Melaleuca quinquenervia with occasional Eucalyptus tereticornis. Xanthorrhoea johnsonii is abundant in the ground layer. Stream Sediment & Morphology Report 15 June 2010

23 Photo Plate 1: Surface water monitoring SW1 following a significant rainfall event (July, 2008) SW2 Location Located immediately downstream of the proposed mining and infrastructure, near the south eastern border of the MLA (Figure 7). Co-ordinates , (MGA 94, Zone 56) Channel Depth Channel Width Flow Direction Bank Slope Bank Stability Substrate Terracing Water 1 m Approximately 30 m East No banks obvious High, vegetation cover and lack of defined bank provides good stability. Grey to brownish grey fine sandy clay loam None 1 m depth in channel. Stream width approx 25 m across flood plain Stream Sediment & Morphology Report 16 June 2010

24 Debris and Tree Roots Numerous trees and significant ground cover within the waterway. Flood Plain Riparian Vegetation Floodplain is not clearly defined and could extend to approximately 50 m total width in times of high rainfall. Dominated by Melaleuca quinquenervia with occasional Eucalyptus tereticornis. Photo Plate 2: Surface water monitoring SW2 following a significant rainfall event (July, 2008) SW3 Location Located downstream of the proposed MLA, near the intersection of the unnamed waterway and Churchill Mine Road (Figure 7). Co-ordinates , (MGA 94, Zone 56) Channel Depth Channel Width Flow Direction Bank Slope No distinct channel No distinct channel East No bank Stream Sediment & Morphology Report 17 June 2010

25 Bank Stability Substrate Terracing Water High, vegetation cover and lack of defined bank provides good stability. Unknown None 0.2 m depth over 45 m width Debris and Tree Roots No clear channel defined. Numerous trees and significant groundcover within the waterway. Flood Plain Riparian Vegetation Floodplain is not clearly defined and could extend to approximately 50 m total width in times of high rainfall. Dominated by Melaleuca quinquenervia with occasional Eucalyptus tereticornis. Photo Plate 3: Surface water monitoring SW3 following a significant rainfall event (July, 2008) SW4 Location Located in the northern corner of the main MLA, upstream of existing rail infrastructure and access track (Figure 7). Co-ordinates , (MGA 94, Zone 56) Stream Sediment & Morphology Report 18 June 2010

26 Channel Depth Channel Width Flow Direction Bank Slope Bank Stability Substrate Terracing Water 1m Approximately 15m East Gentle High, vegetation cover and lack of defined bank provides good stability. Sandy Clay Loam None Absent Debris and Tree Roots Several trees and thick reeds within the waterway. Flood Plain Riparian Vegetation Floodplain is not clearly defined and could extend to approximately 50 m total width in times of high rainfall. Dominated by Melaleuca quinquenervia with occasional Eucalyptus tereticornis. Photo Plate 4: Surface water monitoring SW4 (Established January, 2010) Stream Sediment & Morphology Report 19 June 2010

27 4.1.1 Summary of Stream Morphology Waterways within the Colton MLA are restricted to 1 st order streams. The streams surveyed are characterised by relatively small channels, defined only in places, and for the most part without obvious banks. Large sections of the stream have no defined channel and appear as low lying ground inundated in times of surface water flow. The streams are considered stable, with little evidence of erosion and good vegetation cover. 4.2 STREAM SEDIMENTS Particle Size Distribution The substrates of the streams within the Project site are typically fine sandy loams to fine sandy clay loams. This is reflected in the results of the particle size analysis undertaken on the sediment samples taken during the field survey. The results of the Particle Size Analyses are shown below in Table 3 below. The full laboratory results are contained in Appendix A. SW1 - SW3 are averaged results of three sampling events between 2008 and SW4 was sampled in 2010 only. The stream substrates on the Project site are typically comprised of sand, silt, and clay. The average ratio of gravel : sand : silt : clay is 5 : 35 : 32 : 29. The results derived from sample sites within the central drainage line (i.e. SW1, SW2, and SW3) show fairly consistent percentages of gravel, sand, silt and clay (Table 3). Sediment samples from SW4 indicate that the drainage line in the northern part of the MLA has a higher percentage of gravel and sand in the substrate than the other survey sites, which consist primarily of silt and clay. Table 3: Particle Size Analysis Site Number Gravel (+ 2mm) (%) Sand (2mm 0.060mm) (%) Silt (0.06mm 0.002mm) (%) Clay (-0.002mm) (%) SW SW2 < SW SW Stream Sediment Metal Concentrations The results of the sediment metal analysis were compared to the Australia and New Zealand Guidelines for Fresh and Marine Water Quality (Australia and New Zealand Environment and Conservation Council (ANZECC) 2000) Aquatic Ecosystem default stream sediment quality guidelines for low and high trigger values as described in Section 3.5 of the guidelines. A summary of the results for each site are presented below, with the full results provided in Appendix A. The ANZECC 2000 Guidelines for Aquatic Ecosystems state that if metal concentrations are below the default low trigger values at the test site (i.e. downstream of the mining disturbances) then there is Stream Sediment & Morphology Report 20 June 2010

28 no need for further investigation. Should the metal concentrations exceed the default trigger values then there is a need to investigate the potential contamination causes (Section 3.1.5, ANZECC 2000). The guidelines also state that in some areas natural mineralisation of stream sediments will mean that levels of some metals will be higher than the default low trigger values or even the high trigger values without any human interference. In these cases, site specific stream sediment low and high trigger levels should be determined from background data. The stream sediment metal concentrations in this report will be used to determine site specific low and high trigger values if any of the ANZECC 2000 stream sediment default values are exceeded. The results of this stream sediment analysis will also be used to set receiving stream sediment Environmental Authority conditions for the Project. Results of the stream sediment analysis determined that levels of antimony, arsenic, beryllium, cadmium, copper, silver, zinc, and mercury were all below the detectable limits for each sample site. All other analytes (arsenic, barium, chromium, cobalt, lead, manganese, nickel, and vanadium) were detectable at one or more sediment sample sites. All results were well below the ANZECC 2000 default low trigger limits. Based on these results, it is proposed that the Project use the ANZECC 2000 default triggers when setting receiving stream sediment conditions in the Environmental Authority for the Project site. A summary of the average results is presented in Table 4. Complete stream sediment results are provided in Appendix A. Table 4: Stream Sediment Quality Results Parameter Units Low Trigger Limit High Trigger SW1 SW2 SW3 SW4 Antimony mg/kg 2 25 <5 <5 <5 <5 Arsenic mg/kg <5 <5 <5 <5 Barium mg/kg n/a n/a Beryllium mg/kg n/a n/a <1 <1 <1 <1 Cadmium mg/kg <1 <1 <1 <1 Chromium mg/kg Cobalt mg/kg n/a n/a <2 <2 <2 <2 Copper mg/kg <5 <5 <5 <5 Lead mg/kg Manganese mg/kg n/a n/a <5 Nickel mg/kg <2 <2 2 <2 Silver mg/kg <2 <2 <2 <2 Vanadium mg/kg n/a n/a Zinc mg/kg <5 <5 <5 <5 Mercury mg/kg <0.1 <0.1 <0.1 <0.1 Stream Sediment & Morphology Report 21 June 2010

29 4.3 SURFACE WATER QUALITY Water samples were collected from the waterways at four sample sites (SW1, SW2, SW3 and SW4) located on and downstream of the Project site. The average water quality of waterways on the Project site is presented in Table 5. This data is presented along side average water quality for the nearby Saltwater Creek and the Mary River. The full results are provided in Appendix B. Water quality at monitoring points on and downstream of the Project site was relatively good and did not exceed the ANZECC (2000) Livestock Drinking Water guidelines, however some parameters did exceed the ANZECC (2000) Aquatic Ecosystems guidelines (refer to Table 5). Based on sampling events in July 2008 and March 2010, water quality within the Project site was found to be within the ANZECC 2000 Livestock Drinking Water triggers for all parameters. When compared to the ANZECC 2000 Aquatic Ecosystems triggers, Aluminium exceeded the default trigger levels at all sites on both monitoring occasions. The background levels of Aluminium are considered to be high as a result of natural mineralisation. Other parameters were found to slightly exceed Aquatic Ecosystems triggers at some monitoring locations during the 2010 sampling event only. These included ph, chromium, lead, zinc, cadmium and copper. Additional data is required to accurately determine the background levels of these parameters. Water quality within Saltwater Creek was more variable, with total Copper, Chromium, Aluminium, Zinc, Electrical Conductivity, and ph all being above the Aquatic Ecosystems trigger values. A limited number of parameters were tested at the Mary River, however, data shows that both ph and electrical conductivity exceed Aquatic Ecosystem criteria. In the event that the natural water quality exceeds the default triggers, the Queensland Water Quality Guidelines 2009 provide procedures for deriving local guidelines for aquatic ecosystem protection. These guidelines recommend the collection of at least 18 samples per reference site within a 12 month period, and setting the new triggers based on 20 th and 80 th percentiles. Stream Sediment & Morphology Report 22 June 2010

30 Table 5: Water Quality Results Trigger Limits Survey Results Reference Site Results Parameter Units ANZECC (2000) Livestock Drinking Water ANZECC (2000) Aquatic Ecosystems SW1 SW2 SW3 SW4 (1 sample only) Saltwater Creek Mary River (range) ph ph Unit n/a Conductivity (EC) at 25ºC µs/cm n/a Total Alkalinity (CaCO3) Total Dissolved Solids Total Suspended Solids mg/l n/a n/a mg/l 4000 n/a n/a mg/l n/a n/a Soluble Ca mg/l 1000 n/a n/a Total Cl- mg/l n/a n/a Soluble Mg mg/l n/a n/a n/a Total Mn mg/l n/a n/a Soluble Na mg/l n/a n/a n/a SO4 mg/l 1000 n/a n/a Stream Sediment & Morphology Report 23 June 2010

31 Trigger Limits Survey Results Reference Site Results Parameter Units ANZECC (2000) Livestock Drinking Water ANZECC (2000) Aquatic Ecosystems SW1 SW2 SW3 SW4 (1 sample only) Saltwater Creek Mary River (range) Total Al mg/l n/a Total B mg/l <0.05 <0.05 <0.05 < n/a Total Cr mg/l <0.001 < <0.02 Total Pb mg/l n/a Total Zn mg/l < < n/a Total Co mg/l 1.0 n/a < n/a Total Fe mg/l n/a n/a n/a Total Ni mg/l <0.001 < n/a Total Se mg/l <0.01 <0.01 <0.01 <0.01 <0.01 n/a Total Cd mg/l < < < n/a Total As mg/l < n/a Total Cu mg/l <0.001 < n/a Stream Sediment & Morphology Report 24 June 2010

32 Trigger Limits Survey Results Reference Site Results Parameter Units ANZECC (2000) Livestock Drinking Water ANZECC (2000) Aquatic Ecosystems SW1 SW2 SW3 SW4 (1 sample only) Saltwater Creek Mary River (range) Dissolved K mg/l n/a n/a <1 <1 <1 <1 4 n/a Stream Sediment & Morphology Report 25 June 2010

33 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 STREAM MORPHOLOGY Overall, the condition of the streams on the Project site appears to be good with little evidence of mass sediment movement or significant erosion. In most cases, where erosion has occurred it appears to have been of low significance or simply part of the natural erosion and deposition cycle of the system. In order to maintain these natural processes it is recommended that disturbance within the streams and adjacent to their bank should be minimised and riparian vegetative cover should be maintained wherever possible across the Project site. 5.2 STREAM SEDIMENTS As stream sediment testing showed all analytes with results either below the limit of detection or below the low ANZECC 2000 default triggers, it is recommended that stream sediment conditions should be set based on the default triggers. 5.3 WATER QUALITY Water quality for samples obtained from SW1, SW2, SW3 and SW4 recorded results exceeding the ANZECC 2000 Aquatic Ecosystems triggers for total Aluminium. Slight exceedance of other parameters was also recorded on occasion. Other, more significant waterways in the area include Saltwater Creek and the Mary River. Water quality data was also presented for these two waterways, which were found to exceed the default trigger levels for total Copper, Chromium, Aluminium, Zinc, Electrical Conductivity, and ph. It is clear that water ways on and in the vicinity of the Project site have existing water quality above Aquatic Ecosystem triggers, particularly for Aluminium. Additional samples (minimum 18 events) will be needed to determine suitable receiving water monitoring criteria for the Project. 5.4 RECOMMENDATIONS The Projects proposed activities have the potential to effect streams downstream of the Project through: Soil erosion of disturbed mine areas in high rainfall events adding to the sediment load and changing the water and sediment quality in the streams; and Changes to the catchment areas of the streams on the Project site could either increase or decrease the water flow volumes through the streams in rainfall events leading to increased erosion of the stream banks or reduction in water available for riparian vegetation. The following are recommendations for the management of streams on the Project site to prevent unnecessary environmental impacts from the Project on these systems: Any land disturbance within streams beds and adjacent to their bank should be kept to a minimum and stabilised immediately on completion of works; Stream Sediment & Morphology Report 26 June 2010

34 Where large areas of catchments or streams are to be disturbed by mine landforms, clean storm water upstream of the landforms should be diverted around the land disturbances and directed into the same catchment or stream downstream. Measures should be employed to not significantly increase the volume or flow velocities of waters being diverted; All major land disturbances on the Project site that may have the potential to produce soil erosion or excessive sediment during storm events (i.e. waste rock dumps) should be drained via sediment traps to drop out suspended sediment prior to discharge of stormwater to natural stream systems; Progressive rehabilitation of land disturbances during the Project life should be undertaken where possible to reduce the potential for excessive sediment loads from disturbed land; A regular stream sediment and morphology monitoring program should be conducted both upstream and downstream of any mining or infrastructure related disturbances once Project construction has commenced. The monitoring program should include an adequate number of upstream background sites so that natural variations in stream sediment quality and morphology are also monitored. The sites should be monitored for stream sediment quality for analysis parameters as described in this report and photographed for stream morphology; The default low and high trigger values for stream sediments as set out in the ANZECC 2000 Aquatic Ecosystem Guidelines should be used in setting the Environmental Authority conditions for all metals; Should the stream sediment monitoring program detect metal concentrations downstream of mining activities higher than the low or high trigger values then an investigation into the likely causes should be initiated. The results of the investigation and mitigation strategies, if necessary, should be reported to the Department of Environment and Resource Management. An event-based monitoring program should be implemented for receiving water quality, sampling both upstream and downstream of any mining or infrastructure disturbance. As per the recommendations within the Queensland Water Quality Guidelines 2009, in order to set site-specific water quality parameters, a minimum of 18 water samples per site within 12 months will be required to be analysed. Saltwater Creek should continue to be monitored to provide reference data from a site that will not be influenced by disturbances within the Project site, however upstream land uses of Saltwater Creek should be taken into consideration, and if disturbance types exceed the slightly to moderately disturbed category that the waterway within the Project site falls into, a more representative reference site should be chosen. Stream Sediment & Morphology Report 27 June 2010

35 6.0 REFERENCES ANZECC (2000). Australian Water Quality Guidelines for Fresh and Marine Water Quality. Australia and New Zealand Environment and Conservation Council, and Agriculture and Resource Management Council of Australia and New Zealand, Canberra. Conrick, D. and Cockayne, B. (2001). Queensland Australian River Assessment System (AusRivAS). Sampling and Processing Manual. Department of Natural Resources and Mines, Rocklea. QEPA (2003) Guideline 8 Preparing an environmental management overview strategy (EMOS) for non-standard mining projects. Environmental Protection Agency. QEPA (2009) Queensland Water Quality Guidelines Ver 3. Department of Environment and Resource Management. QEPA (2008) Mary Basin Wetland Summary Information ( 138.jsp) Stream Sediment & Morphology Report 28 June 2010

36 Appendix A: Stream Sediment Data Stream Sediment & Morphology Report A June 2010

37 Stream Sediment -Maryborough Site Date Client Sample ID ALS Sample Number Percent Percent Percent Percent Sand Silt Total Gravel Clay (2 mm - ~0.060 (~0.060mm - Recoverable (+ 2 mm) (-0.002mm) mm) 0.002mm) Antimony Arsenic Barium Beryllium Cadmium Chromium Cobalt Copper Lead Manganese Nickel Silver Vanadium Zinc Mercury %w/w %w/w %w/w %w/w %w/w mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg % Percent Cobble (+ 6 cm) SW1 8/09/2008 EB <5 <5 <10 <1 <1 6 <2 <5 6 6 <2 <2 9 <5 < /02/2009 EB <1 < <5 <5 30 <1 < < <2 25 <5 < /01/2010 EB < <5 <5 <10 <1 <1 8 <2 < <2 <2 36 <5 < AVG < <5 <5 10 <1 < <5 < Moisture Content 103 C) SW2 8/09/2008 EB <5 <5 10 <1 <1 4 <2 < <2 <2 23 <5 < /02/2009 EB <1 < <5 <5 20 <1 <1 9 <2 < <2 <2 19 <5 < /01/2010 EB <1 < <5 <5 10 <1 <1 6 <2 < <2 <2 19 <5 < AVG <1 < <5 <5 10 <1 < <2 < <2 < <5 < SW3 8/09/2008 EB <5 <5 30 <1 <1 8 3 < <2 17 <5 < /02/2009 EB < <5 <5 <10 <1 <1 4 <2 <5 <5 14 <2 <2 12 <5 < /01/2010 EB < <5 <5 30 <1 < < <2 27 <5 < AVG < <5 <5 20 <1 < <2 < < <5 < SW4 7/01/2010 EB < <5 <5 30 <1 <1 5 <2 <5 9 <5 <2 <2 29 <5 <

38 Appendix B: Water Quality Data Stream Sediment & Morphology Report B June 2010

39 CAS Number Units LOR SW1 SW1 SW2 SW2 SW3 SW3 SW4 SW4 Date EA005: ph ph Value ph Unit EA010P: Conductivity by PC Titrator Electrical 25 C µs/cm EA015: Total Dissolved Solids Total Dissolved C GIS mg/l EA025: Suspended Solids Suspended Solids (SS) mg/l ED037P: Alkalinity by PC Titrator Hydroxide Alkalinity as CaCO3 DMO mg/l 1 <1 <1 <1 <1 <1 <1 <1 Carbonate Alkalinity as CaCO mg/l 1 <1 <1 <1 <1 <1 <1 <1 Bicarbonate Alkalinity as CaCO mg/l Total Alkalinity as CaCO3 mg/l ED040F: Dissolved Major Anions Sulfate as SO mg/l ED045G: Chloride Discrete analyser Chloride mg/l ED093F: Dissolved Major Cations Calcium mg/l 1 <1 1 <1 2 <1 2 3 Magnesium mg/l 1 <1 2 <1 3 <1 3 3 Sodium mg/l Potassium mg/l 1 <1 <1 <1 <1 <1 <1 <1 EG020F: Dissolved Metals by ICP-MS Aluminium mg/l Arsenic mg/l <0.001 <0.001 <0.001 < <0.001 <0.001 Cadmium mg/l < < < < < < < Chromium mg/l <0.001 <0.001 <0.001 < < Copper mg/l <0.001 <0.001 < <0.001 < Cobalt mg/l < < < Nickel mg/l <0.001 <0.001 <0.001 <0.001 <0.001 < Lead mg/l < < <0.001 <0.001 Zinc mg/l <0.001 < <0.001 < Manganese mg/l < < < Selenium mg/l < < <0.01 <0.01 Boron mg/l 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 Iron mg/l EG020T: Total Metals by ICP-MS Aluminium mg/l Arsenic mg/l <0.001 <0.001 < < Cadmium mg/l < < < < < Chromium mg/l <0.001 <0.001 <0.001 <0.001 < Copper mg/l <0.001 <0.001 <0.001 <0.001 < Cobalt mg/l <0.001 <0.001 < < Nickel mg/l <0.001 <0.001 <0.001 <0.001 < Lead mg/l < < Zinc mg/l <0.001 <0.005 < <0.001 < Manganese mg/l < < < Selenium mg/l 0.01 <0.005 <0.01 <0.005 <0.01 <0.005 <0.01 <0.01 Boron mg/l 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 Iron mg/l EN055: Ionic Balance Total Anions meq/l Total Cations meq/l