APPENDIX 4 – MINE WATER RELEASES REPORT
BYERWEN COAL PTY LTD – BYERWEN COAL PROJECT
BYERWEN COAL PROJECT
Mine Water Releases
Prepared for: QCOAL PTY LTD 40 Creek Street BRISBANE QLD 4000
Prepared by: Kellogg Brown & Root Pty Ltd ABN 91 007 660 317 Level 11, 199 Grey Street, SOUTH BANK QLD 4101 Telephone (07) 3721 6555, Facsimile (07) 3721 6500
3 December 2013
BEW106-TD-WE-REP-0008 Rev. 0
CONTENTS
Section Page
1 INTRODUCTION
2 RELEASE CRITERIA
2.1 Upper Suttor River Sub-Catchment 2-2 2.2 Rosella Creek Sub-Catchment 2-10
3 EFFECT OF RELEASES
3.1 Suttor River 3-1 3.2 Kangaroo Creek 3-5
4 CONCLUSIONS
5 REFERENCES
BEW106-TD-WE-REP-0008 Rev. 0 iii 3 December 2013 1 Introduction
The proposed mine water management strategy for the Byerwen Coal Project was described in Appendix 11 of EIS. This included details of the water management philosophy, expected water quality from the mine affected catchments, release strategy, proposed water infrastructure, water balance model and likely effects on hydrology, hydraulics and water quality. Since that report was prepared and based on discussions with the Department of Environment and Heritage Protection (EHP), the Department of Natural Resources and Mines (DNRM), and the Department of Science Information Technology, Innovation and the Arts (DISITIA), there have been some modifications to the proposed water quality objectives and release criteria which affect some of the water quality predictions associated with the Project. The purpose of this report is to explain the basis for the modified release criteria and to provide updated water quality predictions and impact assessment in the receiving environment upstream and downstream of the proposed mine. Water quality predictions are made using the water balance model detailed in the mine water management strategy (KBR 2013a). It is noted that the impact on water quality in the Suttor River associated with the mine water releases described herein, is based on revised water quality objectives for the Suttor River, updated as per discussions with EHP, DNRM and DISITIA, which is addressed in KBR (2013b), and on which this report relies.
BEW106-TD-WE-REP-0008 Rev. 0 1-1 3 December 2013 2 Release criteria
The proposed release criteria for the Project have been developed based on the Model Mining Conditions Guideline (EM944) – Version 4, 26 June 2013 (EHP, 2013) and have been developed with the objective of ensuring releases do not result in unacceptable water quality in the receiving environment. Several factors are considered when deriving release criteria in order to ensure this objective is met including:
• receiving environment flow
• receiving environment water quality
• mine release rate
• mine release water quality. Each of these aspects is described below to explain the basis for selection of the proposed criteria.
2.1 UPPER SUTTOR RIVER SUB-CATCHMENT
2.1.1 Derivation of release criteria
Receiving environment flow Mine releases will only occur when flow conditions in the receiving environment are above a minimum level, and are derived from a runoff event. Runoff can be separated into two components:
• surface runoff (storm flow), defined as the immediate runoff response of a catchment due to saturated soils or rainfall intensity becoming greater than soil infiltration rate
• base flow, typically the delayed runoff response of a catchment and is caused by shallow infiltration that later feeds the surface water systems. An analysis of the hydrological regime of Suttor River was conducted in order to determine the flow threshold at which base flow dominates. The hydrological modelling approach was based on the Australian Water Balance Model (AWBM) and is detailed in Appendix 11 of the EIS. A comparison was made between observed data recorded at Eaglefield gauge on Suttor River and modelled runoff. The location of Eaglefield gauge is shown on Figure 2.2 and site details listed in Table 2.1. The comparison between observed and modelled duration curves are shown in Figure 2.2, suggesting that the hydrological model is suitable.
BEW106-TD-WE-REP-0008 Rev. 0 2-2 3 December 2013 Table 2.1 Streamflow gauge details
Station 120304A Station 120218A Name Suttor River at Eaglefield Kangaroo Creek at Byerwen Long/Lat 147.7143/-21.4504 147.9250/-21.1130 Catchment Area (km2) 1915 371 Data Period 17/08/1967 - Current 06/06/1979 - 01/10/1988 Data Completeness 84% 35%
BEW106-TD-WE-REP-0008 Rev. 0 2-3 3 December 2013 Figure 2.1 GAUGING STATIONS USED FOR AWBM VERIFICATION
BEW106-TD-WE-REP-0008 Rev. 0 2-4 3 December 2013 10000
1000 Observed runoff at Eaglefield Modelled runoff at Eaglefield 100
10 (m3/s)
Flow 1
0.1
0.01
0.001 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percentage of samples equalled or exceeded
Figure 2.2 AWBM MODEL AT EAGLEFIELD (SUTTOR RIVER) The hydrograph was filtered using automated techniques described in Arnold et al (1995) to identify the baseflow component and the typical flow conditions at which baseflow prevails. Alternative methods were also used as a check, such as visual inspection of the hydrographs to identify the recession curve. The dominant flow regime is provided in Figure 2.3. This shows the component of runoff comprising “storm flow”. Approximately 15% of the time the flow in Suttor River is predominately “storm flow”.
Storm flow Base flow 100% dominated dominated
90%
80%
70% "Stormflow"
60%
comprising 50%
40% Runoff
of 30%
20% Component 10%
0% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percentage of samples equalled or exceeded
Figure 2.1 FLOW REGIME EXCEEDENCE CURVE
BEW106-TD-WE-REP-0008 Rev. 0 2-5 3 December 2013 Figure 2.4 shows in more detail the components of flow contributing to the hydrograph. The flow threshold at which storm flow and base flow components are equal is 0.75 m3/s. This value represents flow that is predominantly derived from a runoff event and therefore mine releases could occur.
10000 Storm flow component of Runoff 1000 Base flow component of Runoff Runoff
100
10 /s) 3 (m 1 "Base flow" dominant below 0.75 m3/s Flow 0.1
0.01
0.001
0.0001 0% 20% 40% 60% 80% 100% Probability of Samples Equalled or Exceeded
Figure 2.2 BASE FLOW AND STORM FLOW COMPONENTS OF RUNOFF AT EAGLEFIELD (SUTTOR RIVER) Since there is no pre-existing gauge at the proposed flow gauging station for Byerwen, it is necessary to scale the hydrograph and proposed flow thresholds from the Eaglefield gauge to the proposed location. This is performed by scaling by catchment area, as presented in Table 2.2.
Table 2.2 Derivation of low flow / recession flow trigger Suttor River @ Eaglefield gauge Suttor River @ (120304A) Byerwen Catchment area (km2) 1,915 825 Base flow / Storm flow 0.75 0.3 threshold (m3/s) (derived above) (scaled by catchment area) Adopted threshold (m3/s) 0.5
While the base flow / storm flow threshold is estimated to be 0.3 m3/s at the proposed gauging station at Byerwen, a conservative value of 0.5 m3/s (factor of safety of more than 1.5) has been adopted as the low/recession flow trigger. Triggers for medium, high, very high and flood flow regimes have been derived by analysis of the hydrograph. The frequency of exceedence for each flow regime is presented in Table 2.3. The very high and flood flow regimes are rarely met, and there is an even split between frequency of exceedance of the other flow regimes, suggesting that the proposed flow triggers are reasonable.
BEW106-TD-WE-REP-0008 Rev. 0 2-6 3 December 2013 Table 2.3 Frequency of exceedance of nominated flow triggers Flow trigger Frequency of Flow regime (m3/s) exceedance (%) Low/Recession 0.5 13.5 Medium 1 10.9 High 5 5.2 Very High 15 2.2 Flood 50 0.7
Receiving environment water quality It is proposed to establish a water quality monitoring location downstream of the mine which can be used as a compliance point and referred to in an Environmental Authority (EA). Water quality between the release location(s) and the compliance point would not be influenced by third parties, such as discharges from Glencore’s Newlands Coal Project. The proposed compliance monitoring location is at the Byerwen lease boundary on the Suttor River, downstream of all potential mine releases. The proposed location is shown in Figure 2.5. In order to develop suitable water quality objectives at this location, a revised methodology and approach to deriving trigger values that will be representative of local site conditions is detailed in KBR (2013b). Releases from the mine would be structured such that they do not result in an increase in EC at the compliance location above the 75th percentile, which is 701 µS/cm, as per (KBR 2013b).
Mine release rate The proposed release rates have been derived such that it is less than or equal to the natural flow in the receiving environment at the flow gauging station. The release rate has also been selected on the basis of dilution calculations in the receiving environment, using conservative end of pipe and receiving environment assumptions, incorporating a factor of safety. The proposed maximum combined release rate is shown in Table 2.4, together with the receiving flow trigger (derived earlier).
Table 2.4 Comparison between flow trigger and maximum combined release rate Receiving environment Maximum combined Flow regime flow trigger (m3/s) release rate (m3/s) Low/Recession 0.5 0.5 Medium 1.0 0.5 High 5.0 2.0 Very High 15.0 4.0 Flood 50.0 10.0
BEW106-TD-WE-REP-0008 Rev. 0 2-7 3 December 2013 Mine release water quality Maximum limits have been derived for end-of-pipe releases to the environment. These vary depending on the flow in the receiving environment. The limits are within the ranges suggested within the Model Mining Conditions Guideline (EM944) – Version 4, 26 June 2013 (EHP, 2013). They have been further customised on the basis of dilution calculations in the receiving environment, incorporating a factor of safety.
2.1.2 Proposed release criteria The proposed release criteria for releases to Suttor River are presented in Table 2.5. The monitoring locations referred to in the table are shown on Figure 2.5.
Table 2.5 Proposed release criteria – Suttor River Suttor River Suttor River Flow regime Upstream @ Mine discharges Downstream @ flow gauging compliance point station (MP1) (CP1) Upstream flow Maximum combined End of pipe EC Maximum EC trigger^ discharge limit during release Low/Recession* >0.5 m3/s 0.5 m3/s 701 µS/cm 701 µS/cm Medium 1-5 m3/s 0.5 m3/s 1,200 µS/cm 701 µS/cm High 5-15 m3/s 0.5 m3/s 3,000 µS/cm 701 µS/cm 2.0 m3/s 1,300 µS/cm Very High 15-50 m3/s 1.0 m3/s 4,500 µS/cm 701 µS/cm 4.0 m3/s 1,600 µS/cm Flood >50 m3/s 2.0 m3/s 6,500 µS/cm 701 µS/cm 10.0 m3/s 2,000 µS/cm
* release is allowed for up to 28 days after flow drops below threshold as per EM944 (EHP, 2013)
BEW106-TD-WE-REP-0008 Rev. 0 2-8 3 December 2013
Figure 2.3 PROPOSED FLOW GAUGING AND COMPLIANCE MONITORING LOCATION
BEW106-TD-WE-REP-0008 Rev. 0 2-9 3 December 2013 2.2 ROSELLA CREEK SUB-CATCHMENT
2.2.1 Derivation of release criteria
Receiving environment flow Using the same approach as described above for the Upper Suttor River sub- catchment, an analysis of the hydrological regime of Kangaroo Creek was conducted in order to determine the flow threshold at which base flow dominates. A comparison was made between observed data recorded Byerwen gauge on Kangaroo Creek and modelled runoff. The location of Bywerwen gauge is shown on Figure 2.2 and site details listed in Table 2.1. The comparison between observed and modelled duration curves are shown in Figure 2.6, suggesting that the hydrological model is suitable.
1000
100 Observed modelled 10
1 (m3/s)
0.1 Flow
0.01
0.001
0.0001 0% 20% 40% 60% 80% 100% Probability of Samples Equalled or Exceeded
Figure 2.4 AWBM MODEL FOR KANGAROO CREEK (GAUGE 120218A) The hydrograph was filtered to identify the baseflow component and the typical flow conditions at which baseflow prevails. The dominant flow regime is provided in Figure 2.7. This shows the component of runoff comprising “storm flow”. Approximately 10% of the time the flow in Kangaroo Creek is predominately “storm flow”.
BEW106-TD-WE-REP-0008 Rev. 0 2-10 3 December 2013 Storm flow Base flow dominated 100% dominated
90%
80%
70% "Stormflow"
60%
comprising 50%
40% Runoff
of 30%
20% Component 10%
0% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percentage of samples equalled or exceeded
Figure 2.5 FLOW REGIME EXCEEDENCE CURVE Figure 2.8 shows in more detail the components of flow contributing to the hydrograph. The flow threshold at which storm flow and base flow components are equal is 0.57 m3/s. This value represents flow that is predominantly derived from a runoff event and therefore mine releases could occur.
1000 Stormflow component of runoff Baseflow component of runoff 100 Runoff
10
1 /s) 3 "Base flow" dominant below 0.57 m3/s (m
0.1 Flow
0.01
0.001
0.0001 0% 20% 40% 60% 80% 100% Probability of Samples Equalled or Exceeded
Figure 2.6 BASE FLOW AND STORM FLOW COMPONENTS OF RUNOFF FOR KANGAROO CREEK (GAUGE 120218A)
BEW106-TD-WE-REP-0008 Rev. 0 2-11 3 December 2013 Since there is currently no gauge at the proposed flow gauging station for Byerwen, it is necessary to scale the hydrograph and proposed flow thresholds from the Kangaroo Creek gauge (gauge 120218A) to the proposed location. This is performed by scaling by catchment area, as presented in Table 2.6.
Table 2.6 Mine releases
Kangaroo Creek at Kangaroo Creek at gauge 120218A proposed gauging station
Catchment area (km2) 371 110 Base flow / Storm flow 0.57 0.17 threshold (m3/s) (derived above) (scaled by catchment area) Adopted threshold (m3/s) 0.2
The base flow / storm flow threshold is estimated to be 0.17 m3/s at the proposed gauging station at the mine, and a value of 0.2 m3/s has been adopted as the low/recession flow trigger. Triggers for medium, high, very high and flood flow regimes have been derived by inspection of the hydrograph. The frequency of exceedance for each flow regime is presented in Table 2.7. The very high and flood flow regimes are rarely met, and there is an even split between frequency of exceedance of the other flow regimes, suggesting that the proposed flow triggers are reasonable.
Table 2.7 Frequency of exceedance of nominated flow triggers Flow trigger Frequency of (m3/s) exceedance (%) Recession 0.2 8.9 Medium 0.2 8.9 High 0.5 5.9 Very High 2 2.2 Flood 7.5 0.5
Receiving environment water quality The proposed water quality monitoring location downstream of the mine which can be used as a compliance point would not be influenced by third parties, such as discharges from Glencore’s Newlands Coal Project. The proposed compliance monitoring location is at the Byerwen lease boundary on Kangaroo Creek, downstream of all potential mine releases. The proposed location is shown in Figure 2.5. The approach to developing water quality objectives at this location is unchanged from that presented in the EIS, however the reference site dataset is now larger, has been filtered for no flow periods and adopts the 75th percentile instead of the 80th percentile. These changes had a very minor effect on the proposed EC trigger value at this location, from 1,270 µS/cm to 1,252 µS/cm. This is detailed in a revised version of KBR (2013b).
BEW106-TD-WE-REP-0008 Rev. 0 2-12 3 December 2013 Releases from the mine would be structured such that they do not result in an increase in EC at the compliance location above the 75th percentile, which is 1,252 µS/cm.
Mine release rate The proposed release rates have been derived such that it is less than or equal to the natural flow in the receiving environment at the flow gauging station. The release rate has also been selected on the basis of dilution calculations in the receiving environment, using conservative end of pipe and receiving environment assumptions, incorporating a factor of safety. The proposed maximum combined release rate is shown in Table 2.8, together with the receiving flow trigger (derived earlier).
Table 2.8 Comparison between flow trigger and maximum combined release rate Receiving environment Maximum combined Flow regime flow trigger (m3/s) release rate (m3/s) Recession 0.2 0.2 Medium 0.2 0.1 High 0.5 0.3 Very High 2 1.0 Flood 7.5 2.0
Mine release water quality Maximum limits have been derived for end-of-pipe releases to the environment. These vary depending on the flow in the receiving environment. The limits are within the ranges suggested within the Model Mining Conditions Guideline (EM944) – Version 4, 26 June 2013 (EHP, 2013). They have been further customised on the basis of dilution calculations in the receiving environment, incorporating a factor of safety.
2.2.2 Proposed release criteria The proposed release criteria for releases to Kangaroo Creek are presented in Table 2.9. The monitoring locations referred to in the table are shown on Figure 2.5.
Table 2.9 Proposed release criteria – Kangaroo Creek Kangaroo Creek Kangaroo Creek @ Flow regime @ flow gauging Mine discharges compliance point station Upstream flow Maximum combined End of pipe EC Maximum EC trigger^ discharge limit during release Recession* >0.2 m3/s 0.2 m3/s 1,252 µS/cm 1,252 µS/cm Medium 0.2-0.5 m3/s 0.1 m3/s 1,600 µS/cm 1,252 µS/cm High 0.5-2 m3/s 0.1 m3/s 2,100 µS/cm 1,252 µS/cm 0.3 m3/s 1,550 µS/cm Very High 2-7.5 m3/s 0.2 m3/s 3,000 µS/cm 1,252 µS/cm 1.0 m3/s 1,600 µS/cm Flood >7.5 m3/s 0.5 m3/s 4,000 µS/cm 1,252 µS/cm 2.0 m3/s 2,000 µS/cm
* release is allowed for up to 28 days after flow drops below threshold as per EM944 (EHP, 2013)
BEW106-TD-WE-REP-0008 Rev. 0 2-13 3 December 2013 3 Effect of releases
3.1 SUTTOR RIVER
3.1.1 Mine Releases Releases will only be permitted when the Suttor River is flowing or has recently flowed. The water balance model indicates that releases are only expected to occur around 5% of time the Suttor River is flowing. Therefore the majority of the time the mine will not affect water quality in the Suttor River. The discharge criteria are based on five flow bands. The releases in each flow band are summarised in Table 3.1. This indicates that the majority of water is released in the “high” flow band, followed by “very high” and “medium” flow bands. The flood and low/recession account for the least volume of water released.
Table 3.1 Mine releases
Release condition Frequency Volume released
Low/Recession 11% 7% Medium 49% 26% High 24% 34% Very High 14% 28% Flood 3% 5%
3.1.2 Suttor River Hydrology Daily runoff over a 46 year period (equivalent to the mine life) was calculated for two scenarios: without the Project; with the Project. The flow duration curve for both scenarios is presented in Figure 3.1.
BEW106-TD-WE-REP-0008 Rev. 0 3-1 3 December 2013 10,000.0
1,000.0 /s) 3 100.0 Without the Project With the Project
10.0 Discharge (m Discharge
1.0
0.1 0% 20% 40% 60% 80% 100%
Percentage of Samples Equalled or Exceeded
Figure 3.1 FLOW DURATION CURVE – SUTTOR RIVER AT COMPLIANCE POINT As can be seen in the figure, the mine has a negligible impact on Suttor River hydrology. This is because the Suttor River catchment is much larger than the catchment affected by mining, so any influence is significantly dampened.
3.1.3 Suttor River Electrical Conductivity Figure 3.2 shows the modelled EC distribution in the Suttor River at the flow gauging station and at the compliance point using the proposed release conditions. There is no effect above the 75th percentile and only a very slight increase observable below the 75th percentile across all flow events. The changes to the distribution are small because releases from the mine are rare (i.e. only 5% of the time when the Suttor River is flowing) and the proposed release conditions incorporate a substantial factor of safety. During mine releases the EC at the compliance point usually increases. The inset in Figure 3.2 shows this increase by including data only at times when the mine is releasing. Under no circumstances does the EC at the compliance location exceed 701 µS/cm during a release event. Figure 3.3 shows the magnitude of the EC change in the Suttor River as a result of releases from the Project. This shows that most of the time (95% of the time when the river is flowing) the Project has no effect on Suttor River EC. This is primarily because releases from the mine are rare. The inset in Figure 3.3 depicts the magnitude of the EC change in the Suttor River at times when discharges are occurring from the mine. This indicates that almost three- quarters of the time when discharges occur the EC at the compliance point increases by less than 100 µS/cm. The increase is less than 200 µS/cm 90% of the time and the maximum predicted increase is 530 µS/cm. As noted earlier, under no circumstances does the EC in receiving environment exceed 701 µS/cm during a release event.
BEW106-TD-WE-REP-0008 Rev. 0 3-2 3 December 2013 2,000
MINE RELEASE EVENTS ONLY 1,800 800 700 Water Quality Objective 701 µS/cm 1,600 600 500
1,400 400
EC (µS/cm) 300
1,200 200 100
0 1,000 LEGEND 5th 15th 25th 35th 45th 55th 65th 75th 85th 95th Percentile Modelled EC at Flow
EC (µS/cm) EC Gauging Station ~5% OF ALL FLOW EVENTS 800 Modelled EC at Compliance Point
600
400
200
0 5th 10th 15th 20th 25th 30th 35th 40th 45th 50th 55th 60th 65th 70th 75th 80th 85th 90th 95th Percentile ALL FLOW EVENTS Figure 3.2 MODELLED EC DISTRIBUTION IN THE SUTTOR RIVER
BEW106-TD-WE-REP-0008 Rev. 0 3-3 3 December 2013 100
90 100 MINE RELEASE EVENTS ONLY 90 80 80 70 70 60 50 60 40 30 50 20 Frequency of occurance(%) 10 40 0 0 0 0 0 0 0 00 6 o 10 o 40 o 50 t t t to 600 ve
Frequency of occurance (%) Frequency ow -100 0 0 o 30 l -100 to 00 to 20 00 to 300 be 1 2 30 400 500 ab EC change (µS/cm) ~5% OF ALL FLOW EVENTS 20
10
0
0 0 0 0 0 00 00 0 0 0 00 to 1 3 4 5 6 6 0 o 0 to to 1 0 0 to 0 0 t - 00 to 0 0 0 below -100 100 to 200 2 3 4 5 above EC change (µS/cm) ALL FLOW EVENTS
Figure 3.3 MODELLED EC CHANGE IN THE SUTTOR RIVER
BEW106-TD-WE-REP-0008 Rev. 0 3-4 3 December 2013 3.2 KANGAROO CREEK
3.2.1 Mine releases Releases will only be permitted when Kangaroo Creek is flowing or has recently flowed. The water balance model indicates that releases are only expected to occur around 3% of the time Kangaroo Creek is flowing. Therefore the majority of the time the mine will not affect water quality in Kangaroo Creek. The discharge criteria are based on five flow bands. The releases in each flow band are summarised in Table 3.2. This indicates that the majority of water is released in the “very high” and “flood” flow bands, with a large proportion of low EC water released under recessional flow conditions.
Table 3.2 Mine releases
Release condition Frequency Volume released
Low/Recession 55% 25% Medium 6% 1% High 13% 9% Very High 16% 31% Flood 10% 34%
3.2.2 Suttor River Hydrology Daily runoff over a 46 year period (equivalent to the mine life) was calculated for two scenarios: without the Project; with the Project. The flow duration curve for both scenarios is presented in Figure 3.4.
BEW106-TD-WE-REP-0008 Rev. 0 3-5 3 December 2013 100
10 Without the Project With the Project
1 (m3/s)
0.1 Dishcarge
0.01
0.001 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percentage of Samples Equalled or Exceeded
Figure 3.4 FLOW DURATION CURVE – KANGAROO CREEK AT COMPLIANCE POINT As can be seen in the figure, the mine has a negligible impact on Kangaroo Creek hydrology. This is because the mine rarely releases and the Kangaroo Creek catchment is much larger than the catchment affected by mining, so any influence is significantly dampened.
3.2.3 Kangaroo Creek Electrical Conductivity Figure 3.5 shows the modelled EC distribution in the Kangaroo Creek at the flow gauging station and at the compliance point using the proposed release conditions. There is negligible effect on EC percentiles across all flow events. The changes to the distribution are negligible because releases from the mine are rare (i.e. only 3% of the time when the Kangaroo Creek is flowing) and the proposed release conditions incorporate a substantial factor of safety. During mine releases the EC at the compliance point is increased relative to the flow gauging station for the lower EC percentiles, and reduced in the higher EC percentiles. The reduction in EC in the higher percentiles is due to the high natural salinity of the Kangaroo Creek catchment. The inset in Figure 3.5 shows this trend by including data only at times when the mine is releasing. Under no circumstances does the EC at the compliance location exceed 1,252 µS/cm during a release event. Figure 3.6 shows the magnitude of the EC change in Kangaroo Creek as a result of releases from the Project. This shows that most of the time (97% of the time when the river is flowing) the Project has no effect on Kangaroo Creek EC. This is primarily because releases from the mine are rare. The inset in Figure 3.6 depicts the magnitude of the EC change in Kangaroo Creek at times when discharges are occurring from the mine. This shows that the mine releases sometimes increase the EC in the receiving environment, and sometimes reduce the EC in the receiving environment. Most of the change is in the range +/- 200 µS/cm.
BEW106-TD-WE-REP-0008 Rev. 0 3-6 3 December 2013 As noted earlier, under no circumstances does the EC in receiving environment exceed 1,252 µS/cm during a release event.
BEW106-TD-WE-REP-0008 Rev. 0 3-7 3 December 2013
1,400
1,200
1,000
MINE RELEASE EVENTS ONLY 800 1300 1200 Water Quality Objective 1,252 µS/cm 1100 LEGEND 1000 Modelled EC at Flow
EC (µS/cm) EC 600 900 Gauging Station 800 Modelled EC at 700 Compliance Point 600 500 EC (µS/cm) 400 400 300 200 100 0 200 5th 15th 25th 35th 45th 55th 65th 75th 85th 95th Percentile ~3% OF ALL FLOW EVENTS
0 5th 10th 15th 20th 25th 30th 35th 40th 45th 50th 55th 60th 65th 70th 75th 80th 85th 90th 95th Percentile ALL FLOW EVENTS Figure 3.5 MODELLED EC DISTRIBUTION IN KANGAROO CREEK
BEW106-TD-WE-REP-0008 Rev. 0 3-8 3 December 2013
100
90 100 MINE RELEASE EVENTS ONLY 80 90 80 70 70 60
60 50 40 30 50 20 Frequency (%) Frequency occurance of 10 40 0
0 0 0 00
Frequency of occurance (%) 700 60 50 400 300 400 600 600 - - - - - 30 o o o o -100 to 100 to 2 o 300 to t to t ow 0 0 t 0 t -100 to 0 0 0 t bel 100 20 300 to 400 to 500500 above -700 -60 -500 -40 -300 to --20020 EC change (µS/cm) 20 ~3% OF ALL FLOW EVENTS
10
0
0 0 0 0 0 00 0 00 0 0 00 to 1 200 3 400 5 6 6 -1 o o e t to v ow 100 0 to 0 t 0 to o l - 0 b be 100 200 to 3 40 500 a EC change (µS/cm) ALL FLOW EVENTS
Figure 3.6 MODELLED EC CHANGE IN KANGAROO CREEK
BEW106-TD-WE-REP-0008 Rev. 0 3-9 3 December 2013 4 Conclusions
The proposed release criteria for the Byerwen Coal Project are based on the Model Mining Conditions Guideline (EM944) – Version 4, 26 June 2013 (EHP, 2013). Release criteria were developed with the objective of ensuring releases do not result in unacceptable water quality in the receiving environment. The proposed release criteria will not result in any change to existing EC distributions in the receiving environment above the proposed water quality objective. Receiving environment flow triggers have been derived so that mine releases will only occur when flow conditions in the receiving environment are above a minimum level, and are derived from a runoff event. The water balance model indicates that releases are only expected to occur around 5% of time the Suttor River is flowing and 3% of the time Kangaroo Creek is flowing. The impact on river hydrology is negligible. The predicted change in the EC distribution is only a very slight increase observable below the 75th percentile across all flow events. The changes to the distribution are small because releases from the mine are rare and the proposed release conditions incorporate a substantial factor of safety. When considering the effect on the EC distribution only at times of mine discharge, there is a small EC increase in the Suttor River, and a variable effect on EC in Kangaroo Creek. However under no circumstances does the EC at the compliance location exceed the water quality objective during mine discharges.
BEW106-TD-WE-REP-0008 Rev. 0 4-1 3 December 2013 5 References
Arnold et al. (1995), Automated Base Flow Separation and Recession Analysis Techniques from GROUND WATER Vol. 33 No.6 November–December 1995
EHP (2013), Model Mining Conditions Guideline (EM944) – Version 4, 26 June 2013
KBR (2013a), Mine Water Management Strategy – Byerwen Coal Project, 28 February 2013
KBR (2013b), Assessment of Surface Water Environmental Values – Byerwen Coal Project, 3 December 2013
BEW106-TD-WE-REP-0008 Rev. 0 5-1 3 December 2013
APPENDIX 5 – ASSESSMENT OF SURFACE WATER ENVIRONMENTAL VALUES REPORT
BYERWEN COAL PTY LTD – BYERWEN COAL PROJECT
BYERWEN COAL PROJECT
Assessment of Surface Water
Environmental Values
Prepared for: QCOAL PTY LTD 40 Creek Street BRISBANE QLD 4000
Prepared by: Kellogg Brown & Root Pty Ltd ABN 91 007 660 317 Level 11, 199 Grey Street, SOUTH BANK QLD 4101 Telephone (07) 3721 6555, Facsimile (07) 3721 6500
3 December 2013
BEW106-TD-EV-REP-0001 Rev. 3
CONTENTS
Section Page
EXECUTIVE SUMMARY
1 INTRODUCTION
1.1 Purpose 1-1 1.2 Regulatory framework 1-1
2 CATCHMENT DESCRIPTION
2.1 Catchment overview 2-1 2.2 Rosella Creek subcatchment 2-3 2.3 Upper Suttor River subcatchment 2-8
3 ENVIRONMENTAL VALUES AND WATER
QUALITY OBJECTIVES
3.1 Environmental values 3-1 3.2 Rosella Creek subcatchment – Draft environmental values 3-1 3.3 Suttor River subcatchment – Draft environmental values 3-2 3.4 Classification of existing aquatic ecosystems 3-5 3.5 Default water quality guidelines 3-5 3.6 Interrogation of available data 3-8 3.7 Water Quality Rosella Creek subcatchment 3-12 3.8 Upper Suttor River Subcatchment 3-20 3.9 Environmental monitoring program 3-28
4 CONCLUSIONS AND RECOMMENDATIONS
5 REFERENCES
APPENDICES A Summary Water Quality Data
BEW106-TD-EV-REP-0001 Rev. 3 iii 3 December 2013
Executive Summary
This report provides an assessment of the existing surface water environmental values with the potential to be impacted by the Byerwen Coal Project (‘the Project’). The report provides technical information which will be input into the project Environmental Impact Statement (EIS) and Additional Information to the Environmental Impact Statement (AIEIS). The report is written in the context of environmental values as defined by the Environmental Protection (Water) Policy 2009 (EPP (Water)).
The Project is located within the Rosella Creek and Upper Suttor River subcatchments of the Bowen River catchment and Suttor River catchment respectively. These catchments constitute part of the headwaters of the Burdekin Basin. Two key watercourses have been identified within the study area. Kangaroo Creek drains the northern section of the proposed open cut operations, subsequently flowing into Rosella Creek, which drains into the Bowen River. The southern portion of the Project area is drained by the Suttor River which subsequently collects into the Burdekin Falls Dam downstream of its confluence with the Belyando River.
No environmental values are attributed by the EPP (Water) to the watercourses within the study area; therefore site-specific environmental values for the receiving water were derived from a review of land and downstream water uses within the relevant subcatchments. This exercise was augmented by a review of a qualitative assessment of subcatchment environmental values provided within the Burdekin Water Quality Improvement Plan Catchment Atlas (Dight, 2009).
The ecosystem condition that is most appropriate for affected waterways under the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC, 2000) (herein referred to as the ANZECC guidelines), is a ‘slightly to moderately disturbed (SMD) system’. The appropriate water types are ‘upland streams’ and ‘lowland streams’, as defined by the Queensland Water Quality Guidelines (DEHP, 2009) (QWQG). The QWQG (Central Coast Queensland Regional Guideline Values for Physico-Chemical Indicators) were used as the default water quality guidelines for the Project area. Generally, site specific water quality objectives are preferred where sufficient information is available, in order to protect the local environmental values.
A review of baseline water quality monitoring data for the study area revealed that for certain parameters such as pH, electrical conductivity (EC) and total suspended solids (TSS), background levels consistently exceeded the default guideline values. Therefore, given that specific water quality objectives for the Burdekin Basin have not as yet been scheduled under
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the EPP (Water), a draft set of specific water quality objectives were derived specifically for the Rosella Subcatchment.
A trigger value for EC was derived for the Suttor River subcatchment. The default water quality objectives defined in the QWQG has been adopted for all other parameters within the Suttor River subcatchment.
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1 Introduction
1.1 PURPOSE Kellogg Brown & Root Pty Ltd (KBR) has been commissioned by Byerwen Coal Pty Ltd (the proponent) to undertake an assessment of the existing environmental values of surface water resources which would potentially be affected by the Byerwen Coal Project (‘the Project’). This report provides technical information that supports the project Environmental Impact Statement (EIS) and addresses the water quality component of the Terms of Reference for the project, and has been updated for the purpose of the Additional Information for the Environmental Impact Statement (AIEIS). The report is written in the context of environmental values as defined by the Environmental Protection (Water) Policy 2009 (EPP (Water)). The report defines the environmental values of the study area and summarises the results of various water quality monitoring programs in order to present and define the baseline water quality for the study area. The report is also informed by the results of a site visit undertaken in September 2012. The report then derives Water Quality Objectives (WQO) that will protect the identified environmental values. These have been derived using site-specific data where possible, modelled derivations and default water quality guidelines. Potential impacts on surface water quality are discussed in the Mine Water Management Strategy report (KBR 2013), along with the release limits, water management infrastructure and other mitigation measures necessary to protect the surface water environmental values identified in this report. Impacts on aquatic ecology are addressed within the Aquatic Ecology Impact Assessment Report prepared by AMEC Environment & Infrastructure Pty Ltd (AMEC).
1.2 REGULATORY FRAMEWORK
1.2.1 Water Act 2000 The Water Act 2000 provides the basis for the planning, allocation and use of Queensland water resources. Under the Act the provision of water for uses such as irrigation, stock watering, drinking and industry must make allowances for the environmental requirements that support the ecological health of a water resource. This Act provides criteria to determine if a drainage feature is considered to be a watercourse under the Act and therefore required to comply with specific criteria
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which regulate the interference with water or with a watercourse, including for example the diversion of a watercourse. A watercourse as defined under the Act must have certain characteristics of a channel of a river, creek or other stream between the outer banks laterally and between upstream and downstream limits longitudinally. It does not include a drainage feature and must have flow that persists after rain has ceased. Officers of the former Department of Environment and Resources Management (DERM, now the Department of Natural Resources and Mines (NRM)) inspected the waterways within the Project area and defined the extent of watercourses as per the Act (DERM letter of 19 July 2012). Further details of their advice are provided in Section 2.2 and 2.3.
1.2.2 Environmental Protection (Water) Policy 2009 The EPP (Water) seeks to protect and/or enhance the suitability of Queensland’s waters for various beneficial uses. The policy identifies environmental values for waters within Queensland and guides water quality objectives to protect the environmental values of any water resource. The Burdekin Basin catchment area and its tributaries are currently not included under Schedule 1 of this Policy, which lists the environmental values and water quality objectives for certain waterways waters within Queensland. As such, a generic set of environmental values for waters to be protected or enhanced have been adopted. It should be noted that environmental values and water quality objectives for this catchment are currently under review and are scheduled to be published by December 2013.
1.2.3 Water Resource (Burdekin Basin) Plan 2007 Under the Water Act 2000, water resource plans have been prepared for specific parts of Queensland in order to advance the sustainable management of water. The Water Resource (Burdekin Basin) Plan 2007 has the following purposes:
to define the availability of water in the plan area
to provide a framework for sustainably managing water and the taking of water
to identify priorities and mechanisms for dealing with future water requirements
to provide a framework for establishing water allocations
to provide a framework for reversing, where practicable, degradation that has occurred in natural ecosystems
to regulate the taking of overland flow water. The plan applies to:
water in a watercourse or lake
water in springs
overland flow water.
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The Burdekin Resource Operations Plan 2009 (amended 2010) implements the provisions made by the Water Resource (Burdekin Basin) Plan 2007. This is achieved by the specification of rules and operational requirements for managing surface water resources in the basin.
1.2.4 Water Quality Guidelines and Assessment Tools The ANZECC guidelines provide guideline values or descriptive statements for different indicators to protect aquatic ecosystems and human uses of water (e.g. primary recreation, human drinking water, agriculture, stock watering). These guidelines are a broad-scale assessment and it is recommended that, where applicable, locally relevant guidelines are adopted. The Queensland Water Quality Guidelines (QWQG) (DERM, 2009a) are intended to address the need for locally relevant criteria identified in the ANZECC and Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) Guidelines by:
providing guideline values that are specific to Queensland regions and water types
providing a process/framework for deriving and applying local guidelines for waters in Queensland (i.e. more specific guidelines than those in ANZECC and ARMCANZ).
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2 Catchment description
2.1 CATCHMENT OVERVIEW The Project is located across (straddles) the Suttor River and Bowen River catchment boundary, which are both part of the headwaters of the broader Burdekin River catchment (refer to Figures 2.1 to 2.3). The Burdekin catchment is the second largest in Queensland and covers an area of 133,432 km2. Waterways within the Burdekin catchment vary between largely sandy, ephemeral creek systems to permanently flowing clear-water rivers and creeks that originate in mountain rainforest. The region is characterised by a dry tropical climate, which results in alternating extremes in river flows, from prolonged dry periods of no flow, to substantial flood events. A review of Queensland Wetland Mapping data compiled by EHP indicated that there are no wetlands of international significance (Ramsar Convention) upstream of the Burdekin Falls Dam. The Burdekin Falls Dam is the largest dam in Queensland and is described in the Queensland Wetland mapping data as a lacustrine wetland. The water body is however an artificial and highly modified wetland. While recognised as a wetland by EHP, its ecosystem value is diminished because it is artificial and is operated for flood mitigation and irrigation/drinking water supply purposes. There are two weirs on the Burdekin River downstream of the Burdekin Falls Dam, the Blue Valley Weir and Clare Weir. The Burdekin River discharges to the Pacific Ocean near Ayr. Within the Suttor and Bowen River catchments are subcatchments; specifically, the Project area lies across the Rosella Creek subcatchment (part of the Bowen River catchment) to the north and the Upper Suttor River subcatchment (part of the Suttor River catchment) to the south. An overview of each subcatchment in the Project area is provided below.
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Figure 2.1 BURDEKIN BASIN CATCHMENTS
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2.2 ROSELLA CREEK SUBCATCHMENT
2.2.1 Subcatchment description The northern part of the Project area is located within the Rosella Creek subcatchment of the Bowen catchment (refer to Figure 2.2). This subcatchment covers an area of 1,473 km2. The principal land use within the subcatchment is grazing on native pastures. Approximately 20% of the land area is set aside for conservation and minimal use. Due to long-term grazing activities the condition of the waterways and riparian habitat in the subcatchment has undergone major decline over the last 30 years due to extensive clearing of the floodplain (Burdekin Water Quality Improvement Plan 2009 [Dight, 2009]). Hill slope erosion is identified by the Burdekin Water Quality Improvement Plan technical panel as the major source of sediment and particulate nutrients affecting water quality in the Rosella Creek subcatchment, while gully and streambank erosion are also predicted to make substantial contributions. The rate of soil erosion is predicted to be moderate and below the overall Burdekin Basin average, while the total soil loss from the subcatchment is comparatively low compared to other basin subcatchments. Land condition is assessed as having the highest proportion in fair condition, with roughly equal proportions of good and poor condition. Water quality in the Rosella Creek subcatchment has been predicted by the Burdekin Water Quality Improvement Plan technical panel to be relatively poor, with elevated concentrations of sediment leaving the subcatchment.
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Figure 2.2 ROSELLA CREEK SUBCATCHMENT
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2.2.2 Drainage lines The Project area encompasses ninety five riverine systems or drainage lines mapped by EHP within the Rosella Creek subcatchment (AMEC, 2012). These include: One 4th order stream (Kangaroo Creek) Five 3rd order streams Sixteen 2nd order streams Seventy-three 1st order streams. A letter of advice regarding watercourse determinations was provided to the proponent by DERM on 19 July 2012. Officers of DERM advised that within the Rosella Creek subcatchment part of the Project area two watercourses met the characteristics of water courses under the Water Act 2000. These include Kangaroo Creek and a tributary of Kangaroo Creek (refer to Figure 2.3). Kangaroo Creek is located in the upper reaches of the Rosella Creek subcatchment and drains the northern section of the proposed open cut operations. Within the Project area, Kangaroo Creek consists of a largely sandy, ephemeral watercourse with sections of cobbles in the upper reaches. The bed and banks are generally sharply defined, as shown in Plates 2.1 to 2.3. Sections of the upper reaches accessed on 26 September 2012 consisted of a series of pools while closer to the north eastern edge of the Project area, recessional baseflows were encountered (refer to Plate 2.2). Locations of photographs are shown on Figure 2.3. Kangaroo Creek becomes Rosella Creek downstream of the Project boundary, as shown in Figure 2.2. Rosella Creek itself is a largely sandy, dry seasonal creek system with limited habitat availability, although waterholes are present that create aquatic habitat in places (Dight, 2009). Prior to this EIS, the ecology and condition of aquatic habitats in the subcatchment had not been studied in detail and as such the available historical information is somewhat limited (refer to Section 3.1.1). Further details regarding the existing aquatic ecology are presented within the Aquatic Ecology Impact Assessment Report (AMEC, 2012). Rosella Creek flows generally north and discharges into the Bowen River and then the Burdekin River downstream of the Burdekin Falls Dam.
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Figure 2.3 WATERCOURSES WITHIN THE NORTHERN PART OF THE PROJECT AREA
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Plate 2.1: KANGAROO CREEK LOOKING UPSTREAM OF CERITO ROAD CROSSING
Plate 2.2: RECESSIONAL BASEFLOWS IN KANGAROO CREEK LOOKING DOWNSTREAM OF CERITO ROAD CROSSING
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Plate 2.3: COBBLED SECTION IN UPPER REACHES OF KANGAROO CREEK LOOKING UPSTREAM
2.3 UPPER SUTTOR RIVER SUBCATCHMENT
2.3.1 Subcatchment description The southern part of the Project is situated in the 5,155 km2 Upper Suttor River subcatchment (refer to Figure 2.4). The overall Suttor Basin is approximately 18,153 km2 and land use consists almost exclusively of grazing on natural and modified pastures. Other minimal land uses include dryland cropping of cereal. The riparian habitat of the subcatchment has deteriorated over the last 30 years, principally due to clearing along headwater streams and on the floodplains, and is currently assessed to be in poor condition. As with the Rosella Creek subcatchment, the ecology and condition of aquatic habitats has previously not been studied in detail and as such the available information is somewhat limited; however, the waterways are understood to include numerous in-channel and off-channel water bodies that are likely to be highly and persistently turbid (Dight, 2009). Watercourses in the catchment are highly ephemeral. Water quality in the Upper Suttor River subcatchment is predicted to be moderately impacted by suspended sediment during wet season event flows, with elevated concentrations in the lower reaches of the subcatchment. Similar to the Rosella Creek subcatchment, hillslope erosion is identified as the major source of sediment and particulate nutrients affecting water quality within the Suttor Basin, while gully erosion is also identified as a significant contributor. Water quality in the Suttor Basin is predicted by the Burdekin Water Quality Improvement Plan technical panel to have moderately elevated suspended sediment concentrations and loads at end-of-basin during wet season event flows (Dight, 2009).
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Figure 2.4 UPPER SUTTOR RIVER SUBCATCHMENT
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2.3.2 Drainage lines Within the Upper Suttor River subcatchment, the Project area encompasses 15 riverine systems or drainage lines including:
One 5th order stream (the Suttor River)
One 3rd order stream
Three 2nd order streams
Ten 1st order streams. Within and immediately upstream and downstream of the Project area, the Suttor River consists of a large sandy, meandering watercourse. The river is ephemeral, with flow recorded at Eaglefield gauging station (approximately 25 km downstream of the Project area) less than 40% of the time. Recessional baseflows linking a series of pools were encountered during a site visit on 26 September 2012. The bed and banks of the river are sharply defined. Refer to Plates 2.4 to 2.5. The Suttor River discharges into the Belyando River which ultimately drains to the Burdekin Falls Dam.
Plate 2.4: SUTTOR RIVER AT MINING LEASE WESTERN BOUNDARY LOOKING DOWNSTREAM
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Plate 2.5: SUTTOR RIVER AT MINING LEASE WESTERN BOUNDARY LOOKING UPSTREAM Officers of DEHP advised that a single tributary of the Suttor River within the project area meets the characteristics of a watercourse under the Water Act 2000. This ephemeral water course is labelled ‘Tributary 1’ on Figure 2.5 and flows from east to west across the southern section of the Project area. The watercourse was accessed at two locations on 26 September 2012. As shown in Plates 2.6 to 2.9 the watercourse is ephemeral and generally sandy and the morphology of the channel ranges from sharply eroded and incised to gentle vegetated slopes. Isolated pools were observed. The tributary of the Suttor River labelled as ‘Tributary 2’ on Figure 2.5 can be described as a dry, sandy, ephemeral drainage line. As shown on Plates 2.10 and 2.11 the banks and low flow channel are poorly defined. A lacustrine wetland (artificial) located along this drainage line is described within Section 3.1.2 and within the Aquatic Ecology Impact Assessment Report (AMEC, 2012).
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Figure 2.5 WATERCOURSES WITHIN THE SOUTHERN PART OF THE PROJECT AREA
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Plate 2.6: TRIBUTARY 1 APPROXIMATELY 1 KM FROM SUTTOR RIVER LOOKING DOWNSTREAM
Plate 2.7: TRIBUTARY 1 APPROXIMATELY 1 KM FROM SUTTOR RIVER LOOKING UPSTREAM
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Plate 2.8: TRIBUTARY 1 AT NORTHERN MISSING LINK RAILWAY LINE CROSSING LOOKING DOWNSTREAM
Plate 2.9: TRIBUTARY 1 AT NORTHERN MISSING LINK RAILWAY LINE CROSSING LOOKING UPSTREAM
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Plate 2.10: TRIBUTARY 2 ADJACENT TO NORTHERN MISSING LINK RAILWAY LINE CROSSING UPSTREAM
Plate 2.11: TRIBUTARY 2 APPROXIMATELY 0.6 KM UPSTREAM OF SUTTOR RIVER LOOKING DOWNSTREAM
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3 Environmental values and water quality objectives
3.1 ENVIRONMENTAL VALUES Under the EPP (Water), the protection of the receiving environment is guided by the identification of environmental values that pertain to those waters. Environmental values are defined in DEHP (2010) as ‘a quality or physical characteristic of the environment that is conducive to ecological health or public amenity or safety’. Environmental values require protection from the effects of pollution, waste discharge and modified sediment processes. Currently there are no environmental values established for the Burdekin Basin Catchment, as per Schedule 1 of the EPP (Water) 2009. Environmental values adopted for the receiving waterways have therefore been identified based on a review of land uses and downstream water usage patterns within the relevant subcatchments. The Burdekin Water Quality Improvement Plan (2009) (BWQIP) presents a qualitative assessment the subcatchments and this was also referenced. The environmental values for each of the two subcatchments are listed within Table 3.1 and discussed below.
Table 3.1 Draft environmental values for the Burdekin Catchment
Rosella Creek Subcatchment Upper Suttor River Subcatchment
Aquatic ecosystems Aquatic ecosystems Stock watering Stock watering Industrial users Industrial users Cultural and spiritual Cultural and spiritual Human consumption Primary recreation Secondary recreation Visual recreation Drinking water
3.2 ROSELLA CREEK SUBCATCHMENT – DRAFT ENVIRONMENTAL VALUES
Aquatic ecosystems As in the case of other drainage lines within the subcatchment, Kangaroo and Rosella Creeks experience flow only after sustained or intense rainfall. Stream flows are highly variable with most channels drying out and aquatic fauna concentrating in senescing pools in the drier months. As a consequence, physical attributes, water
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quality and the composition of aquatic floral and faunal communities are also expected to be highly variable over time. The aquatic ecosystem values of the subcatchment are considered to be slightly too moderately disturbed as a consequence of the surrounding land use for cattle grazing.
Stock watering Land use in the area is dominated by grazing. Water supply for production of healthy livestock is commonly extracted from the surrounding water resources.
Industrial use Mining has a presence within this catchment and further development is planned. Specifically, the Newlands Coal mine is located immediately to the east of the Project and that operation is likely to be extended within the life of the Project.
Cultural and spiritual The Birriah and Jangga traditional owners have custodial use of water resources within the catchment.
3.3 SUTTOR RIVER SUBCATCHMENT – DRAFT ENVIRONMENTAL VALUES
Aquatic ecosystems The Suttor River and its tributaries are ephemeral streams which can occasionally contain large waterholes. The magnitude of these waterholes and the length of time for which they persist during dry conditions is dependent on the substrate composition and the season and climatic conditions at the time. Similarly the characteristics of the Rosella Creek subcatchment, physical attributes, water quality and the composition of aquatic floral and faunal communities is highly variable over time. This area shows some pre-existing dry land salinity which is likely to result from erosion caused by a combination of both natural processes and anthropogenic land uses such as cattle grazing. This may cause a potential threat to aquatic ecosystems within the catchment. According to the Burdekin Water Quality Improvement Plan technical panel, macroinvertebrate have experienced moderate change along the whole Suttor River. Fish and water quality are moderately affected below the junction with the Belyando River. As described in the Aquatic Ecology Impact Assessment report (AMEC, 2012) two lacustrine wetlands and a single palustrine wetland area are located within or immediately adjacent to the Project footprint (refer to AMEC, 2012 for further details regarding the ecological values of these wetlands). The lacustrine wetlands will be removed as part of the Project. It is understood that the palustrine wetland will be retained, and not physically disturbed by mining activities. Potential impacts on the hydrology and ecology of this wetland are addressed within the Mine Water Management Strategy and Aquatic Ecology Impact Assessment reports respectively. The aquatic ecosystem values of the overall subcatchment are considered to be slightly too moderately disturbed as a consequence of the surrounding land use for cattle grazing.
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Stock watering Land use is almost exclusively grazing on natural and modified pastures. Water supply for production of healthy livestock is commonly extracted from the surrounding water resources.
Primary, secondary and visual recreation Swimming, fishing and camping have been identified activities along the Suttor River.
Industrial uses Coal mining activities are undertaken within this catchment and further development is planned.
Cultural and spiritual values Traditional owners are the Jangga and the Birriah people. Environmental values include:
water access and use
water allocation for traditional owners
water to camp near for traditional activities
participation in the management of water.
Drinking water Drinking water is cited as an environmental value in the BWQIP (2009). There are however no urban areas or towns located downstream of the Project area within the subcatchment and the very small population is widely scattered on pastoral holdings. A review of aerial photography revealed two residences in proximity to the Upper Suttor River. The potential therefore exists for river water to be used for drinking purposes.
Irrigation As stated above, the predominant agricultural land use within the subcatchment is grazing. The nearest property with a license to take water for crop irrigation purposes is located approximately 60 km downstream of the Project area (refer to Figure 3.1).
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Figure 3.1 WATER LICENCE HOLDERS
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3.4 CLASSIFICATION OF EXISTING AQUATIC ECOSYSTEMS The ANZECC guidelines describe how aquatic ecosystems can be subdivided into three levels of protection based on their current condition. These levels of protection include the following: High Ecological Value (HEV) ecosystems – These are essentially unmodified, highly valued aquatic ecosystems in which the ecological integrity is regarded as intact. Slightly to Moderately Disturbed (SMD) ecosystems – These are aquatic ecosystems in which aquatic biodiversity may have been diminished to a small but measurable degree by human activity, but where the biological communities remain in a healthy condition. Highly Disturbed (HD) ecosystems – These are degraded aquatic ecosystems with reduced and/or highly modified ecological values due to human activity. These are degraded aquatic ecosystems with reduced and/or highly modified ecological values due to human activity. The aquatic ecosystem values of the Rosella Creek and Upper Suttor River subcatchments beyond the Project area are considered to be SMD.
3.5 DEFAULT WATER QUALITY GUIDELINES Water quality guidelines are recommended numerical concentration levels or narrative statements that will support and maintain the designated environmental values of a particular water body. They form the basis for determining water quality objectives. There are three main references used to identify guideline values in Queensland: ANZECC Guidelines – These guidelines provide guideline values (numbers) or descriptive statements for different indicators to protect aquatic ecosystems and human uses of waters (e.g. primary recreation, human drinking water, stock watering). For aquatic ecosystems, although the guidelines provide extensive default guideline values, they strongly emphasise the need to develop more locally relevant guidelines. QWQG – The QWQG are intended to address the need identified in the ANZECC guidelines by: – providing guideline values (numbers) that are tailored to Queensland regions and water types – providing a process/framework for deriving and applying more locally specific guidelines for waters in Queensland. EPP (Water) – Environmental values and WQOs have been scheduled under the EPP Water for certain waters within Queensland. The EPP (Water) describes the method for applying the most relevant water quality guidelines (e.g. national, state, local). It states that the most locally relevant guideline will be used in preference to broader guidelines. Therefore, where the QWQG provides water quality guideline values for Queensland waters, it will take precedence over the ANZECC guidelines. It should be noted that for indicators such as toxicants and other industrial and agricultural uses, ANZECC guidelines remain the principal source of information.
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At the time of the assessment, no environmental values or water quality objectives have been scheduled under EPP (Water) for the Burdekin catchment. As such the QWQG for the Central Coast Queensland Regional Guideline Values for Physio- Chemical Indicators for SMD waters have been adopted as default values for both the Rosella Creek and Upper Suttor River subcatchments (refer to Table 3.2). The QWQG revert to the ANZECC guidelines for certain water quality parameters. Note that for freshwaters, the QWQG generally defaults to the ANZECC 2000 guidelines categories of upland and lowland freshwaters. The ANZECC Guidelines suggest the use of elevation to differentiate between the floodplain and the steeper parts of the catchment when defining lowland and upland freshwaters. However, the QWQG also acknowledge that this definition is not applicable in all instances and also broadly defines upland freshwaters as small (first or second order) upland streams that are moderate to fast flowing due to steep gradients with substrates usually consisting of cobbles, gravel or sand. Lowland streams are defined by the QWQG as larger (>3rd order streams), slow flowing and meandering streams with very slight gradients and substrates which are rarely comprised of cobble and gravel but more often of sand, silt or mud. All watercourses within the study area are located at elevations above the suggested 150 m for lowland freshwaters. It is however considered more appropriate to consider the broader QWQG definitions of freshwaters.
Table 3.2 Default trigger values for catchments in the project area
Parameter Units Default Trigger Value Default Trigger Value Lowland* Upland*
pH (flow) pH Units Lower – 6.5 Lower – 6.5 Upper – 8.0 Upper – 7.5 pH (nil flow or flood event) pH Units Lower – 5.5 Lower – 5.5 Upper – 9.0 Upper – 9.0 Electrical Conductivity µS/cm 168 168 (Upper Suttor)# Electrical Conductivity µS/cm 271 271 (Rosella)# Turbidity NTU 50 25 Sulfate mg/L 250 250 Total Suspended Solids mg/L 10 – Petroleum hydrocarbons µg/L 20 20 (C6–C9) Petroleum hydrocarbons µg/L 100 100 (C10–C36) Ammonia µg/L 900 900 Total Nitrogen mg/L 0.5 0.25 Oxidised Nitrogen mg/L 0.06 0.015 Total Phosphorus mg/L 0.05 0.03 Nitrate mg/L 1.1 1.1 Fluoride (total) mg/L 2 2
Metals** Aluminium µg/L 55 55 Arsenic µg/L 13 13 Boron µg/L 370 370
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Parameter Units Default Trigger Value Default Trigger Value Lowland* Upland* Cadmium µg/L 0.2 0.2 Chromium µg/L 1 1 Cobalt µg/L 90 90 Copper µg/L 2 2 Iron µg/L 300 300 Lead µg/L 4 4 Manganese µg/L 1,900 1,900 Mercury µg/L 0.2 0.2 Molybdenum µg/L 34 34 Nickel µg/L 11 11 Selenium µg/L 10 10 Silver µg/L 1 1 Uranium µg/L 1 1 Vanadium µg/L 10 10 Zinc µg/L 8 8
* Default trigger values derived from DEHP (2013), QWQG or ANZECC (2000) ** Metals trigger values based on 95th percentile protection levels (as reported in DEHP 2013) # Conductivity values derived using 75th percentile protection value for the specific subcatchment (as presented in Appendix G of QWQG)
3.5.1 Assessment of upland and lowland streams Part of the method for the derivation of site specific water quality objectives includes the classification of freshwater streams into either upland or lowland in accordance with the ANZECC 2000 guidelines. Based on the information gathered during site investigations as well as desktop analysis, the Suttor River, Suttor Creek and the majority of Kangaroo Creek were considered to be lowland freshwater streams based on the characteristics of each stream. The Suttor Creek, Suttor River and Kangaroo Creek each have characteristics consistent with the guideline definition for lowland freshwaters; they are larger streams with slow flowing, meandering water with a slight gradient. The substrate contained little sign of cobbles/gravels and consisted more of sand, silt and mud. Tributaries of Suttor River and Suttor Creek, as well as the upper reaches of Kangaroo Creek were considered to be upland freshwater streams. This was primarily due to the definition put forward in the QWQG which emphasise moderate, fast flowing steams with steep gradients. The substrate encountered at these tributaries generally consisted of cobbles, gravels and sand with minimal traces of silt and mud. Table 3.3 presents the location of some of the key water quality sampling locations and whether they appear in upland or lowland freshwater streams, Figure 3.2 shows these sample locations. The default trigger values for either upland or lowland are assigned accordingly in the sections which follow.
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Table 3.3 Water quality sampling locations - upland and lowland stream definitions Site Location (Coordinates using Stream Located within Upland / projection GDA94) Lowland Easting Northing BYSW 2 586996 7655010 Kangaroo Creek Upland BYSW 3 587398 7654889 Kangaroo Creek Upland BYSW 5 592356 7645752 Tributary of Suttor River Upland BYSW 6 592109 7643936 Tributary of Suttor River Upland BYSW 8 604587 7641736 Tributary of Suttor Creek Upland BYSW 9 577008 7667008 Suttor River Lowland BYSW 18 585022 7645621 Suttor River Lowland FSS 3 594464 7659555 Cerito Creek Upland FSS 4/WQS05 594180 7663450 Kangaroo Creek Lowland FSS 5 593084 7661322 Kangaroo Creek Lowland FSS 7 610198 7640081 Suttor Creek Lowland FSS 8/WQS04 589319 7635182 Suttor Creek Lowland FSS 10 590359 7631489 Tributary of Suttor Creek Upland FSS 14 596887 7667911 Kangaroo Creek Lowland FSS 15 587619 7697488 Rosella Creek Lowland FSS 16 567372 7622774 Suttor River Lowland WQS 3 599823 7635798 Suttor Creek Lowland
3.6 INTERROGATION OF AVAILABLE DATA A range of water chemistry data has been analysed for each of the subcatchments to describe the water quality characteristics of the respective catchments. This section summarises the water quality indicators of relevance for the Project. These have been used to establish a baseline assessment on which to base the management measures necessary to protect environmental values relevant discussed in Section 3.1 above.
3.6.1 Data source Data was compiled from surface water quality monitoring events undertaken within the Rosella Creek and Upper Suttor River subcatchments within and around the proposed Project site. The data was collected primarily for the Newlands Coal Project (adjacent to the Byerwen Project) between 2006 and 2013; this data was supplemented by data collected by the proponent from 2010 to 2013. During a site visit on 26 September 2012, a series of water quality field measurements were taken at various locations within and immediately adjacent to the Project area. Parameters tested included EC, temperature, turbidity and pH. These field test results were considered in conjunction with the long term water quality data set, as part of the overall analysis of existing water quality. In addition results of field tests and a one-off water quality sampling event undertaken by AMEC during a site visit between 1 and 6 May 2012 were also considered. Sample locations relevant to the Project were selected to describe the physical and chemical parameters of the potentially affected waterways. Table 3.4 and 3.5 identify the sites used in the compilation and analysis of this data. Locations of monitoring sites are shown on Figure 3.2.
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Figure 3.2 SURFACE WATER MONITORING LOCATIONS
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Since the publication of the EIS, additional data has been gathered for the project. Additional monitoring data was collected by the Proponent and as part of the Newlands Coal Project which was made available to the Proponent by Glencore Pty Ltd. This additional data has been included in the datasets used for the derivation of WQOs as outlined in this report.
3.6.2 Data suitability
Rosella Creek Subcatchment Detailed review of the monitoring data revealed that the dataset is adequate with sufficient spatial distribution along the lengths of relevant waterways as well as within tributaries located within the Project areas for the Rosella Creek subcatchment. The number of monitoring events for each parameter ranged widely but was generally considered sufficient for a robust assessment (>18 observations as detailed in the QWQG), except at BYSW3 where there were 10 observations during flow conditions. All of the 7 water quality monitoring sites included multiple wet seasons during the monitoring period for which data was recorded. In the event that a sample was collected during a no flow event (i.e. sample collected from stagnant pool of water) this data was not included in the analysis. Water hardness values varied across the Project area from ‘soft’ (0–59 mg/L) to ‘extremely hard’ (>240 mg/L). The Rosella Creek subcatchment was generally characterised by ‘hard’ to ‘extremely hard’ water values, with the exception of two sites in the very upper reaches of Kangaroo Creek (BYSW2 and BYSW3).
Table 3.4 Summary of Rosella Creek subcatchment water quality monitoring sites
Data Source Site Location Easting Northing Period Total No Flow (GDA94) (GDA94) observations observations (n) (n)
Byerwen BYSW2 Gully south of rail 586996 7655010 Dec 2010 – 29 7 surface line – central site Mar 2013 water BYSW3 Gully north of rail 587398 7654889 Dec 2010 – 14 4 monitoring line – central site May 2011 data – provided by FSS 3 2.5 km downstream 594464 7659555 Dec 2007 – 67 11 Q Coal of Cerito Creek Feb 2012
Newlands FSS04/ Kangaroo Creek 594180 7663450 Dec 2006 – 426 33 Coal Project WQS05 downstream at water May 2013 collated quality station dataset – FSS05 Kangaroo Creek 593083 7661322 Feb 2007 – 224 15 provided by upstream, 1 km west May 2013 Glencore of junction FSS14 1.5 km south of 596887 7667911 Dec 2010 – 363 43 Byerwen waterhole May 2013 FSS15 30 km north of 587619 7697488 Dec 2010 – 281 5 Byerwen lease area May 2013
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Upper Suttor River Subcatchment A review of the Upper Suttor River Subcatchment monitoring data revealed that the dataset collected for the Suttor Creek was robust and comprehensive, however the dataset available for the upper reaches of the Suttor River was smaller. The spatial distribution along the lengths of the Suttor Creek and downstream of the junction between Suttor Creek and Suttor River was sufficient; however, data collected within the Suttor River upstream of the junction with Suttor Creek did not stand up to statistical and modelling interrogation due to the smaller spatial and temporal dataset. In particular, BYSW9 and BYSW18 do not cover multiple wet seasons and the number of samples is skewed by intensive sampling over consecutive days. Although there are 24 observations at BYSW9, during flow events there are only 11 discrete monitoring periods. The Upper Suttor River subcatchment was generally characterised by ‘soft’ to ‘moderate’ water values. The exception to this were the four sites along Suttor Creek, for which hardness values ranged from ‘moderate’ to ‘extremely hard’.
Table 3.5 Summary of Suttor River subcatchment water quality monitoring sites
Data Source Site Location Easting/ Easting/ Period Total No EC Northing Northing observations Flow (n) (n) (n) 592356 7645752 Byerwen BYSW5 Along Suttor Creek Dec 2010 – 13 4 8 surface transport corridor May 2011 water between Newlands monitoring and Suttor Creek data – BYSW6 2 km south of 592109 7643936 Dec 2010 – 34 15 17 provided by BYSW5 along same Mar 2013 Q Coal transport corridor BYSW8 10 km east of lease 604587 7641736 Dec 2010 – 24 7 16 boundary along Mar 2013 Collinsville– Elphinstone Road BYSW9 4 km south west of 577008 7667008 Mar 2012 – 24 2 20 north western lease Jun 2013 boundary BYSW18 Suttor River on 585022 7645621 Mar 2012 – 6 4 2 western lease May 2012 boundary
Newlands FSS07 8 km east of Suttor 610198 7640081 Nov 2006 – 311 14 277 Coal Project Creek waterhole Apr 2013 collated FSS08/ Suttor Creek, 589319 7635182 Jun 2006 – 739 49 551 dataset – WQS04 southern most point Apr 2013 provided by of Byerwen lease Glencore FSS10 Tributary of Suttor 590359 7631489 Jan 2010 – 29 0 25 Creek, South of Mar 2011 Suttor mining Lease FSS16 Suttor River at Suttor 567372 7622774 Jan 2007 – 86 11 68 Developmental Road Mar 2013 bridge 20 km south west of Byerwen lease WQS03 Suttor Creek, east of 599823 7635798 Nov 2010 – 502 11 362 mining lease Jan 2013
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3.7 WATER QUALITY ROSELLA CREEK SUBCATCHMENT A summary of the baseline water quality monitoring data for the Rosella subcatchments is presented within Tables 3.6 and 3.7. All the results presented below are representative of those recorded during flow events, as no flow events were excluded from the datasets. A summary of the full set of raw water quality monitoring data utilised for this assessment is contained within Appendix A. Appendix A presents the water quality monitoring data per sampling location in the context of minimum, maximum and median values as well as the 20th and 80th percentiles. A discussion of the key water quality indicators is provided after Tables 3.6 and 3.7. Based on the results of the key water quality parameters, it was determined weather further analysis of additional parameters was warranted for the Rosella Creek subcatchment. As recommended in the QWQG, the 75th percentile value is reported for EC. This value has been compared with the median EC value at each monitoring site within the Rosella Creek and Upper Suttor River subcatchments.
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Table 3.6 Summary median water quality data for Rosella Creek subcatchment
Units ANZECC QWQC BYSW2^ BYSW3^ FSS03^ FSS04/WQS05 FSS05 FSS 14 FSS 15 Guideline (upland/lowland) pH(field) pH units 6.5 - 7.5/8.0# 8.2 - 8.3 8.3 8.2 8.3 8.3 pH(lab) pH units 6.5 - 7.5/8.0# 7.7 7.8 8.2 8.3 8.2 8.4 8.4 EC (field) µS/cm 271 192 179 621 1650 1196 2046 1755 EC (lab) µS/cm 271 366 315 1020 1890 1255 2790 2050 Turbidity (lab) NTU 25 / 50 296 340 28 17 2 28 19 TSS mg/L -/10 33 54 37 22 5 32 28 Sulfate dissolved mg/L 250 5 9 171 233 18 242 155 Oxidised Nitrogen mg/L 0.6 / 0.015 0.02 0.02 - - - - - Total Nitrogen mg/L 0.25 / 0.5 1 0.8 0.04 0.12 0.08 0.19 0.03 TDS (lab) mg/L - - 156 2540 274 - - Dissolved Aluminium mg/L 0.055 0.380 0.450 0.010 0.010 0.020 0.010 0.010 Dissolved Boron mg/L 0.37 0.070 0.050 0.06 0.07 0.06 0.08 0.08 Dissolved Copper mg/L 0.0014 0.003 0.003 0.0020 0.0010 0.0010 0.0010 0.0020 Dissolved Manganese mg/L 1.9 0.000 0.000 0.00 0.00 0.00 0.00 0.00 Dissolved Nickel mg/L 0.011 0.005 0.004 0.004 0.003 0.002 0.003 0.002 Dissolved Zinc mg/L 0.008 0.006 0.006 0.005 0.005 0.005 0.005 0.005
Total Aluminium mg/L 0.055 4.50 1.30 1.450 0.510 0.105 0.720 0.730 Total Boron mg/L 0.37 0.07 0.08 0.06 0.07 0.06 0.08 0.08 Total Copper mg/L 0.0014 0.007 0.0062 0.0030 0.0020 0.0020 0.0020 0.0025 Total Manganese mg/L 1.9 0.03 0.01 0.30 0.00 0.01 0.00 0.10 Total Nickel mg/L 0.011 0.01 0.009 0.009 0.008 0.003 0.007 0.005 Total Zinc mg/L 0.008 0.008 0.006 0.010 0.005 0.005 0.006 0.011 Values in RED indicates an exceedance of default trigger value ^ Upland stream # During flow
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Table 3.7 Summary 80th percentile water quality data for Rosella Creek subcatchment
Units ANZECC QWQC BYSW2^ BYSW3^ FSS03^ FSS04/WQS05 FSS05 FSS14 FSS15 Guideline (upland/lowland) pH(field) pH units 6.5 - 7.5/8.0# 8.4 - 8.5 8.4 8.4 8.5 8.5 pH(lab) pH units 6.5 - 7.5/8.0# 8.0 7.9 8.3 8.3 8.4 8.5 8.5 EC (field)* µS/cm 271 282 224 3730 2817 1217 2702 2207 EC (lab)* µS/cm 271 480 345 2794 3474 1260 3503 2882 Turbidity (lab) NTU 25 / 50 465 440 114 70 9 62 66 TSS mg/L -/10 106 128 62 62 13 67 178 Sulfate dissolved mg/L 250 8 10 467 456 23 408 232 Oxidised Nitrogen mg/L 0.6 / 0.015 0.03 0.08 - - - - - Total Nitrogen mg/L 0.25 / 0.5 1.36 1.0 0.14 0.56 0.23 0.72 0.16 TDS (lab) mg/L 169 2910 1268 Dissolved Aluminium mg/L 0.055 0.974 0.788 0.090 0.106 0.050 0.076 0.072 Dissolved Boron mg/L 0.37 0.08 0.08 0.12 0.10 0.08 0.10 0.09 Dissolved Copper mg/L 0.0014 0.004 0.0042 0.0020 0.0020 0.0030 0.0020 0.0020 Dissolved Manganese mg/L 1.9 0.01 0 0.00 0.01 0.01 0.01 0.02 Dissolved Nickel mg/L 0.011 0.008 0.005 0.006 0.006 0.004 0.005 0.003 Dissolved Zinc mg/L 0.008 0.008 0.006 0.010 0.005 0.005 0.005 0.005 Total Aluminium mg/L 0.055 6.68 1.3 9.200 5.174 3.020 4.720 15.920 Total Boron mg/L 0.37 0.08 0.08 0.12 0.10 0.08 0.12 0.10 Total Copper mg/L 0.0014 0.008 0.006 0.0088 0.0070 0.0060 0.0078 0.0182 Total Manganese mg/L 1.9 0.05 0.01 0.3 0.1 0.01 0.2 0.6 Total Nickel mg/L 0.011 0.013 0.009 0.022 0.015 0.013 0.014 0.025 Total Zinc mg/L 0.008 0.011 0.006 0.045 0.020 0.016 0.019 0.038 Values in RED indicates an exceedance of default trigger value *Denotes 75th percentile values for electrical conductivity (EC) as per the QWQG Appendix G ^ Upland stream # During flow
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Electrical conductivity The EC data collected for the Rosella Creek subcatchment covers the period between February 2006 and May 2013. The median EC recorded at sites within the subcatchment varied between 256 µS/cm and 2,790 µS/cm. The 75th percentile values generally exceeded 1,000 µS/cm, only two sites did not, BYSW2 and BYSW3. Both of the sites with 75th percentile values below 1,000 µS/cm are located very high in one of the tributaries of Kangaroo Creek. These results indicate that contrary to the 75th percentile QWQG indication of relatively low EC (271 µS/cm) in the broader Burdekin-Bowen zones, the waterways in the Project area appear to have an existing, elevated salinity. A large degree of variation was noted for the EC during periods of heavy rainfall with large spikes and troughs in the summer months. The variation is most likely attributed to evaporative processes concentrating dissolved salts during low flow periods and the effect of dilution from large flows during high flow periods.
pH The QWQG indicate that median pH should range between 6.5 and 7.5 in upland streams and between 6.5 and 8.0 in lowland streams during periods of flow. The results indicate that existing conditions in the study area for upland waterways consistently exceed this range, with typical pH values of between 8.0 and 8.5. This finding is consistent with the nature of the soils within the catchment. The results for the lowland streams also consistently exceed the guideline values. During flood events and periods of no flow, the QWQG trigger value for pH is between 5.5 and 9.0. None of the median or 80th percentile pH values exceeded the QWQG values for periods of no flow or during flood events.
Turbidity The QWQG indicate that turbidity in upland rivers should be less than 25 NTU and for lowland streams less than 50 NTU. The monitoring results indicate that existing conditions in these waterways often exceed the guideline value for upland streams. All the lowland streams noted a median value below the guideline value of 50 NTU and only two sites (FSS05 and BYSW1) noted an 80th percentile value below 50 NTU. Median values for the upland streams all recorded above the guideline value of 25 NTU with as high as 340 NTU recorded within the Rosella Creek subcatchment. Waterways in the region were noted to display typical ephemeral waterway characteristics with an assessment of seasonal variation showing increases in the range of turbidity concentrations during the wet months. Rosella Creek subcatchment is subject to hill slope erosion and waterway bank erosion that will contribute to elevated turbidity, particularly during high flow periods. This may be attributed to the surrounding land use and as a consequence of cattle grazing.
Sulfate The QWQG state that Sulfate levels should not exceed 250 mg/L. The monitoring results indicate that existing levels in these waterways are generally low and do not
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generally exceed this value, with the exception of three sites. The three sites, FSS03, FSS04, and FSS14 have 80th percentile values around 400–440 mg/L, almost double the guideline value.
Aluminium The ANZECC guideline value for aluminium is 0.055 mg/L. For the purpose of this assessment the highly conservative assumption has been made that 100% of the dissolved aluminium is bio-available. Of the recorded 80th percentile dissolved aluminium results the guideline value was exceeded at seven locations, with the highest reported value 0.97 mg/L.
Boron The median and 80th percentile values for dissolved boron were all below the trigger values, therefore providing at least a 95% protection level for the aquatic organisms.
Copper The ANZECC guidelines indicate a 95th percentile protection limit of 0.0014 mg/L for dissolved copper. Both median and 80th percentile values for dissolved copper generally exceed these limits with ranges in 80th percentile concentrations between 0.0018 and 0.0042 mg/L.
Manganese The median and 80th percentile values for dissolved Manganese were below the guideline 95th percentile protection limit of 1.9 mg/L.
Nickel The median and 80th percentile values for dissolved Nickel were below the guideline 95th percentile protection limit of 0.011mg/L.
Zinc The median values for dissolved zinc did not exceed the guideline 95th percentile protection limit of 0.008 mg/L. The protection limit was exceeded by the 80th percentile values at two sites by a small margin.
Metals summary The Rosella Creek subcatchment is subject to hill slope erosion as well as gully and stream bank erosion. In catchments such as this, it is common for some metals to have naturally high background concentrations. While total metal values provide an indication of the total concentration of a metal present in the water column, the majority of these are attached to sediment under the prevalent alkaline conditions and are therefore not bioavailable. Dissolved metals provide a more accurate representation of the bioavailable concentration of the element, and most accurately reflect the protection limits outlined by the ANZECC guidelines. Dissolved (80th percentile) aluminium concentrations within the catchment occur at higher levels than ANZECC guidelines trigger values at most of the sample sites.
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Median copper concentrations identified in the catchment also exceed the guideline trigger values, and to a lesser extent elevated zinc concentrations were also noted. The most likely reason for these high concentrations is attributed to the surrounding geology, where soils with naturally high aluminium, copper and zinc concentrations have been mobilised by erosion and entered the surface water column during flow events. The median of all other dissolved metal concentrations are below the trigger values for the protection of 95% of the aquatic species, or where applicable, below the limit of reporting. It should be noted that the bioavailability of heavy metals is also affected by the hardness of water and therefore guideline trigger values for copper, nickel and zinc require a site specific correction for hardness. As discussed within Section 3.4.1 above, the Rosella Creek subcatchment is generally characterised by ‘hard’ to ‘extremely hard’ water values. When trigger values were corrected upwards, according to site specific hardness (refer to Appendix A), the concentration of dissolved zinc was observed to be below the hardness corrected trigger values across the catchment. Copper was also consistently below the corrected trigger value, with the exception of two sites. The hardness corrected trigger values for the abovementioned metals for each site are presented within Appendix A, alongside the baseline monitoring data. Table 3.6 and 3.7 above present the uncorrected trigger values.
3.7.2 Draft Water Quality Objectives WQOs are numerical concentration levels or narrative statements of indicators established used for the long term management of receiving waters (DERM 2009a). WQOs use are based on the most relevant water quality guidelines but are derived for specific water types based on long term monitoring of unimpacted ‘reference’ sites. While regional WQOs have been developed for Queensland, site-specific WQOs are preferred where sufficient information is available. Specific WQO for the protection of aquatic ecosystems within the Burdekin Basin are not included within Schedule 1 of the EPP (Water). Additionally, the BWQIP states that insufficient data is available from the Burdekin Dry Tropics NRM region to derive locally relevant WQO for freshwater ecosystems. Consequently site specific draft WQO have been derived based on the QWQG and ANZECC guidelines discussed within Section 3.2 above. This section discusses the derivation of WQOs for the study area.
Framework for establishing site-specific water quality objectives As highlighted in the QWQG, WQOs for a particular receiving environment can be derived directly from the identified environmental values in which the WQO are set to protect. As discussed within Section 3.4 and shown in Tables 3.6 and 3.7, at many of the baseline water quality sampling locations, some of the ambient surface water quality indicators exceed those stipulated in the relevant water quality guidelines. As the water quality guidelines cannot be appropriately applied in this instance, the derivation of a more appropriate set of WQO is required using guiding principles highlighted in the QWQG.
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WQO for physical and chemical indicators have been set for the receiving environment of the Project using the following key steps: 1. selecting suitable baseline reference sites 2. defining the water type at the receiving environment 3. calculating guideline values based on reference data sets. This approach is consistent with the recommended approach in the QWQG. Further detail on each of these steps is included in the following sections.
Selecting suitable reference sites Reference sites or baseline sites are sites that are subject to little disturbance and reflect as close as possible to the natural conditions in the area. The QWQG suggest the following criteria should be used to select appropriate reference sites: 1. minimal disturbance locally and upstream of the site 2. no significant point discharge sources nearby 3. sufficient data is available.
Calculating guideline values Guideline values (or WQO) can be derived from the dataset obtained from the reference sites. The recommended approach for the slightly to moderately disturbed receiving environment is to base the guideline values on the 20th and 80th percentiles of the dataset (QWQG). The dataset needs to contain more than 18 data points with 24 data points considered more appropriate. The process for determining guideline values from reference sites is presented in Figure 3.3.
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Figure 3.3 PROCEDURE FOR DETERMINING GUIDELINE VALUES FROM REFERENCE DATA Source: DERM (2009a) Figure A.1
Reference Site for Rosella Creek subcatchment Water quality monitoring sites FSS05, BYSW2 and BYSW3 were considered as potentially suitable for reference sites. The catchment upstream of these locations is not pristine with land uses including grazing on native pastures. The catchment is also traversed by a railway and state controlled road. Potential impacts on water quality include clearing for agricultural purposes as well as previous mining exploration activities. However, the sites are located upstream of any discharge locations of the existing Newlands mine and are considered to be representative of the natural conditions of the area. Of the three sites, the most comprehensive dataset is available for FSS05 with 224 sampling events undertaken over the full spectrum of seasons between February 2007 and May 2013. It was therefore considered that this sampling location is most suitable to act as a reference site. Note that site FSS04 (426 sampling events) was not considered as a reference site on the basis that it is located downstream of discharge points of the Newlands mine. While sampling locations BYSW2 and BYSW3 were considered suitable from a location point of view, the available dataset for these sites was smaller (29 and 14 sample events respectively) and therefore FSS05 was chosen as the key reference location in favour of these sites. Table 3.8 presents a comparison between the default trigger values and the 80th percentile value (75th percentile for EC as per QWQG) at the reference site, which is representative of the ambient surface water quality. Where the 80th percentile values exceeded trigger values, the 80th percentile values have been adopted as the draft water quality objectives. Where there was considered to be insufficient data for a particular parameter at FSS05, data from BYSW2 were used instead.
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Water at FSS05 was classified as ‘hard’, which is typical of the catchment. Guideline trigger values for copper, zinc and nickel were therefore corrected for this level of hardness. Based on the results of the analysis of the key water quality indicators, analysis of all parameters was deemed unnecessary as there were no significant differences between the Default trigger values and the Site Specific data.
Table 3.8 Comparison between guideline values and ambient surface water for site FSS05 Parameter Units Default Trigger Reference Site Draft WQO value 20th %ile Median 80th %ile n Rosella Creek Subcatchment pH(field) pH units 84 6.5 – 8.0** 8.1 8.2 8.4 pH(lab) pH units 8.1 8.2 8.4 144 6.5 – 8.4** EC (field)* µS/cm 678 1124 1196 84 271 1252 EC (lab)* µS/cm 917 1195 1252 143 Turbidity (lab) NTU 50 0.1 2 9 104 50 TSS mg/L 10 - - 13 117 13 Oxidised mg/L 0.06 0.02# 0.02# 0.03# 11# 0.06 Nitrogen Total Nitrogen mg/L 0.5 0.01 0.08 0.23 31 0.5 Total Phosphorus mg/L 0.05 - - - 0 0.05 Sulfate mg/L 250 4 18 23 35 250 (dissolved) Dissolved Metals Aluminium mg/L 0.055 0.010 0.020 0.050 31 0.055 Boron mg/L 0.37 0.05 0.06 0.08 32 0.37 Copper mg/L 0.007~ 0.0010 0.0010 0.0030 33 0.007 Manganese mg/L 1.9 0.00 0.00 0.01 16 1.9 Nickel mg/L 0.06~ 0.001 0.002 0.004 33 0.06 Zinc mg/L 0.04~ 0.005 0.005 0.005 32 0.04 Values in RED indicates an exceedance of default trigger value *Denotes 75th percentile value for electrical conductivity (EC) as per the QWQG Appendix G, see section 3.3 ** During flow # Sourced from BYSW2 ~ Hardness modified trigger value
3.8 UPPER SUTTOR RIVER SUBCATCHMENT The Suttor River is located within the Central Coast Queensland Region as defined in the QWQG and has been identified as slightly to moderately disturbed water within a Lowland Stream. The QWQG and Model Water Conditions (DEHP, 2013) suggest the parameters in Table 3.2 (Section 3.5) be adopted as regional physio-chemical guideline values which have been adopted as default WQOs, see Table 3.9. Based on the data that was collected, the general characteristics of the water quality in the Upper Suttor River subcatchment was typically consistent with the default trigger values with the notable exception being EC. Table 3.10 below shows the median and 75th percentile EC values at a number of surface water quality monitoring locations within the Upper Suttor River subcatchment. All of the monitoring locations reported a 75th percentile EC value above the default water quality objective, most s reported
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median EC values greater than the default WQO as well. As described in Section 3.6, the availability of reliable data in the Upper-Suttor River subcatchment was confined to the Suttor Creek and Suttor River downstream of the confluence with Suttor Creek. Accordingly a suitable site for the derivation of site specific WQOs that are applicable to this reach of the Suttor River was not available. It is noted that while there is not enough suitable water quality data to derive site specific water quality objectives for the Suttor River using the approach detailed in the QWQG, the dataset for Suttor Creek shows that there is a disconnect between the default WQO for EC and what is being monitored in certain parts of the Upper Suttor River subcatchment. In consideration of the above constraints, a back calculation procedure was adopted to establish a realistic water quality trigger value for EC upstream of the confluence between Suttor River and Suttor Creek. The back calculation procedure employed the robust dataset available from within the Suttor Creek and Suttor River downstream of its confluence with Suttor Creek. One of the key concerns regarding the water quality within the Suttor Creek and Downstream of the confluence with Suttor River are the discharges associated with the nearby Newlands Coal Project, operated by Glencore. This established mine releases treated mine affected water to Suttor Creek between the sampling points WQS03 and FSS08. As such, all water sampled downstream of WQS03 is potentially impacted by the Newlands Coal project.
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Table 3.9 Summary EC data for Upper Suttor River subcatchment
Default BYSW5 BYSW6 BYSW8 BYSW9 BYSW18 FSS07 FSS08/WQS04 FSS10 FSS16 WQS 03 trigger value
n 8 17 16 20 2 461 752 25 68 381 Median µs/cm 168 206 161 250 182 160 1343 1102 497 647 1210 75th %ile µs/cm 168 228 183 441 228 179 2186 1348 824 942 1990
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3.8.1 Adopted approach The quality of water at FSS16 is a direct product of the quality of water which flows from Suttor Creek into Suttor River, and the quality of water which flows from the upper reaches of Suttor River to its confluence with Suttor Creek (see Figure 3.4). Given the robust understanding of the quality of water within the Suttor Creek, and Suttor River downstream of the confluence, back calculation of the quality of water in the Suttor River upstream of the confluence is considered an appropriate approach. In summary the robust and reliable EC data available from the Suttor River downstream of the confluence with the Suttor Creek, as well as within Suttor Creek, can be utilised to derive an acceptable WQO for the Suttor River upstream of the confluence.
Mass balance equation Suitable EC datasets exist in Suttor River downstream of the confluence with the Suttor Creek (FSS16), as well as within Suttor Creek, downstream of the Newlands Coal Project (FSS08). It is considered reasonable to assume that these EC datasets are representative of water quality in the reach between the monitoring locations and the confluence of Suttor River with Suttor Creek (at node C and B respectively shown on Figure 3.4) as there are no known potential sources of salinity between FSS08 and FSS16 and the confluence. Figure 3.4 also presents the location of the current monitoring points and the proposed compliance point. Using a mass balance approach (which is considered appropriate as EC is a conservative property) it is possible to back-calculate the EC in Suttor River upstream of the confluence. Figure 3.4 shows the monitoring locations used in the analysis, as well as nodes A, B and C which assist in understand of the approach. Conservation of mass at the confluence can be expressed in the following equation:
QACA+QBCB=QCCC
Where: QA = Flow at node A CA = Concentration at node A QB = Flow at node B CB = Concentration at node B
QC = Flow at node C CC = Concentration at node C
The equation above can be re-arranged and solved for CA (the concentration of salinity at node A). The concentration of salinity at node A will be representative of the salinity in the subcatchment which flows into the confluence from the Suttor River. As EC is a conservative parameter, and there are no known sources of salinity downstream of the proposed mining lease prior to node A, it is likely that the concentration of salinity calculated at node A is representative of the concentration of salinity at the proposed compliance point on Suttor River at the Byerwen lease boundary.
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Figure 3.4 MONITORING LOCATIONS AND NODES
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Methodology The mass balance equation requires estimates of flow at all three nodes (A, B, C). In the absence of flow gauging data at nodes A and B, assumptions around the hydrological response of the subcatchments are required. It was initially assumed that the hydrology of both catchments was similar and that rain fell evenly across both catchments. The uncertainties associated with these assumptions are discussed in Section 3.8.3. The ratio of catchment areas of Suttor River and Suttor Creek measured upstream of the confluence (1,104 km2 and 827 km2 respectively) was used to approximate the contribution from flow generated in each catchment. The measured EC distribution at nodes B and C were used in conjunction with catchment ratios to produce an EC distribution at node A.
3.8.2 Results Table 3.11 presents the EC distribution at nodes A, B and C based on the assumptions presented above. The results indicate that the median (50th percentile) EC in Suttor River at node A is 467 µS/cm and that the majority of the time the EC is within the range of 110 µS/cm (20th percentile) and 742 µS/cm (80th percentile). As suggested in the QWQG, the 75th percentile is an appropriate trigger value for EC. The 75th percentile at node A is 701 µS/cm, as described above, it is reasonable to assume this concentration is representative of and can be adopted for use at the compliance location shown on Figure 3.4.
Table 3.10 EC distributions at nodes A, B, C
Suttor River Suttor River Suttor Creek (compliance (FSS16) (FSS08) point)
(Node C) (Node B) (Node A) Catchment Area (km2) 1931 827 1104 Percentile EC (µS/cm) EC (µS/cm) EC (µS/cm)* 5% 96 135 67 10% 132 214 71 15% 194 287 125 20% 214 353 110 25% 313 440 218 30% 405 512 325 35% 473 588 387 40% 534 689 418 45% 617 815 468 50% 691 991 467 55% 768 1,106 515 60% 848 1,180 600 65% 859 1,234 579 70% 887 1,290 585 75% 981 1,354 701
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Suttor River Suttor River Suttor Creek (compliance (FSS16) (FSS08) point)
(Node C) (Node B) (Node A) 80% 1,032 1,420 742 85% 1,086 1,507 771 90% 1,136 1,710 706 95% 1,881 2,140 1,686
* Calculated value using catchment ratio and a mass balance approach
3.8.3 Uncertainty analysis A number of assumptions were made in this analysis to provide a complete distribution at node A. These include:
hydrology of Suttor River and Suttor Creek catchments are similar
rain falls evenly across both catchments
EC percentiles from Suttor River and Suttor Creek coincide e.g. 10th percentile EC in the Suttor River catchment occurs at the same time as the 10th percentile EC in the Suttor Creek catchment. These assumptions are discussed in the below sections.
Hydrology The hydrology of Suttor River and Suttor Creek catchments are assumed to be similar. That is that similar rainfall on the catchments would result in a similar runoff response. This is considered to be a reasonable assumption as the catchments are located adjacent to one another and have a very similar catchment area (25% size difference). Discharge from the Newlands Coal Project is considered to be negligible compared to runoff from Suttor Creek catchment as the catchment is such a large area (extending past Glenden).
Rainfall Rain is assumed to fall evenly across both Suttor River and Suttor Creek catchments. As runoff usually correlates to EC (higher rate of runoff correlates to lower EC) this also relates to the third assumption that EC percentiles from the catchments would coincide. A Monte Carlo analysis was undertaken within GoldSim to determine the sensitivity of the predictions to this assumption. GoldSim is a powerful Monte Carlo simulation software package that allows the user to quantitatively represent uncertainty in complex systems. The uncertainty of the rainfall assumption was analysed by allowing the coinciding percentiles to be offset by both 10% and 20%. This means that the EC in Suttor River can be higher or lower in percentile (10% or 20% respectively) than Suttor Creek due to either a difference in rainfall depth over the catchment or through natural variance.
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The results of the uncertainty analysis are presented below in Figures 3.5 and 3.6.
Figure 3.5 NODE A EC DISTRIBUTION WITH A 10% PERCENTILE COINCIDENCE UNCERTAINTY
Figure 3.6 NODE A EC DISTRIBUTION WITH A 20% PERCENTILE COINCIDENCE UNCERTAINTY The results show that with an allowable 10% offset in coinciding percentiles (Figure 3.5), the 75% EC percentile at node A, could range from 532 µS/cm to 788 µS/cm (25/75% confidence intervals) and in rare cases range from 495 µS/cm to 863 µS/cm (5/95% confidence intervals).
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With an allowable offset in coinciding percentiles of 20% (Figure 3.6), the 75% EC percentile at node A could range from 485 µS/cm to 878 µS/cm (25/75% confidence intervals) and in rare cases range from 368 µS/cm to 1,654 µS/cm (5/95% confidence intervals). The uncertainty analysis indicates the following:
With a 10% percentile coincidence uncertainty, the effect on the adopted WQO is relatively small (typically ±128 µS/cm and in rare cases ±184 µS/cm). This magnitude of variation in EC is well within the range of fluctuations that are experienced in a natural system.
With a 20% percentile coincidence uncertainty, the effect on the adopted WQO increases. The uncertainty is strongly skewed towards larger ECs. The calculation produces negative ECs at node A in the lower percentiles bands (10th – 45th percentile). This indicates that EC in Suttor Creek is too high (forcing EC at node A to be negative) and should be more similar in percentile to that of the Suttor River catchment. This suggests that the 20% percentile coincidence uncertainty is unlikely to be realised.
Even with a very conservative assumption around percentile coincidence, the resulting WQO in Suttor River at node A is well above the default EC value for the Belyando/Suttor catchment, confirming that the default value is not appropriate for this part of the catchment.
3.8.4 Summary The data in this subcatchment was collected from June 2006 to May 2013. The QWQG specifies a trigger value of 168 µS/cm, which is lower than in the 75th percentile values calculated at all surface water quality sites considered in the Upper Suttor River subcatchment. The median EC values at most sites exceeded the default WQO. These results suggest the waterways in the Project area have a naturally elevated salinity. A more suitable WQO was derived using the understanding of the salinity across the catchment. The WQO derived for the proposed compliance point was 701 µS/cm. By complying with the proposed WQO at the compliance point, it is not predicted that the project would have any unacceptable impacts upon the water quality downstream on the Suttor River.
3.9 ENVIRONMENTAL MONITORING PROGRAM Environmental monitoring will be undertaken within the waterways both upstream and downstream of the Byerwen Coal Project. The monitoring program will include both ecological and water quality monitoring. This will allow the project to understand any impacts as a result of the project on the water quality and the ecological condition of the Suttor River upstream of the confluence with Suttor Creek, as well as in Kangaroo Creek. Figure 3.7 below shows the proposed monitoring locations for the Project.
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Figure 3.7 PROPOSED MONITORING LOCATIONS FOR THE BYERWEN COAL PROJECT
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4 Conclusions and recommendations
This report has identified the environmental values to be protected within the Rosella Creek and Upper Suttor River subcatchments. Based on these environmental values and the recommended water quality guidelines, water quality objectives have been derived for each catchment of the Project area. The draft WQOs for the Rosella Creek subcatchment were derived based on a review of baseline water quality monitoring data and the approach described in the QWQG to select an appropriate reference site. In the Upper Suttor River subcatchment the default WQOs, as outlined in the QWQG, have been adopted for all parameters aside from EC. The draft WQO derived for EC was back calculated based on the understanding of the salinity within the Upper Suttor River subcatchment to ensure that an appropriate WQO was derived which would ensure no unacceptable impact on the environmental values of the Upper Suttor River subcatchment. The draft set of WQOs are presented in Table 4.1. For the majority of parameters in the Rosella Creek subcatchment the default WQOs, as described in the QWQG, have been retained. The exceptions to this are pH, EC and TSS. After reviewing the full set of baseline water quality data, as well as literature provided in the BWQIP, these parameters are high across the Rosella Creek subcatchments and therefore the upward revision of the guidelines is considered appropriate to be used as the basis for future management of water quality for the Project. The draft water quality objectives below will be used as the basis for developing mine water release criteria and a customised approach to management of water quality within the subcatchment areas. The Mine Water Management Strategy report identifies the potential impacting processes on water quality and the management measures necessary to protect the water quality and therefore environmental values of the study area. Specifically this report stipulates the release limits (values that cannot be exceeded) applicable for the Project including those for pH and EC.
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Table 4.1 Draft water quality objectives
Draft WQO Parameter Units Upper Suttor River Rosella Creek Subcatchment Subcatchment
pH (flow) pH units Upper 8.0 8.5 pH units Lower 6.5 6.5 pH (nil flow or flood event) pH units Upper 9.0 9.0 pH units Lower 5.5 5.5 EC µS/cm 701 1252 Turbidity NTU 50 50 TSS mg/L 10 13 Ammonia µg/L 900 900 Petroleum hydrocarbons µg/L 20 20 (C6 – C9) Petroleum hydrocarbons µg/L 100 100 (C10 – C36) Oxidised Nitrogen mg/L 0.06 0.06 Total Nitrogen mg/L 0.5 0.5 Nitrate mg/L 1.1 1.1 Fluoride (total) mg/L 2 2 Total Phosphorus mg/L 0.05 0.05 Sulfate mg/L 250 250 Aluminium µg/L 55 55 Draft WQO Draft WQO Arsenic µg/L 13 13 Boron µg/L 370 370 Cadmium µg/L 0.2 0.2 Chromium µg/L 1 1 Cobalt µg/L 90 90 Copper µg/L 2 7# Iron µg/L 300 300 Lead µg/L 4 4 Manganese µg/L 1,900 1,900 Mercury µg/L 0.2 0.2 Molybdenum µg/L 34 34 Nickel µg/L 11 60# Selenium µg/L 10 10 Silver µg/L 1 1 Uranium µg/L 1 1 Vanadium µg/L 10 10 Zinc µg/L 8 40#
# Hardness modified trigger value, Rosella Creek subcatchment
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5 References
AMEC, 2012, Byerwen Coal Project Draft Aquatic Ecology Impact Assessment, July 2012.
Australia and New Zealand Environment Conservation Council, 2000, Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
DEHP, 2013, Model water conditions for coal mines in the Fitzroy basin, Version 3, March 2013, EM288.
DERM, 2009, Burdekin Basin Resource Operations Plan, Version 2, October 2010.
DERM, 2009a, Queensland Water Quality Guidelines, Version 3, September 2009.
DERM, 2009b, Monitoring and Sampling Manual 2009: Environmental Protection and Water Policy 2009, Version 1 September 2009.
DERM, 2012, Wetland Maps, access at http//www.wetlandinfo.derm.qld.gov.au
Dight, I, 2009, Burdekin Water Quality Improvement Plan, NQ Dry Tropics, Townsville.
KBR, 2013, Byerwen Coal Project Mine Water Releases, Revision 0. Prepared for Qcoal Pty Ltd.
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Appendix A
SUMMARY WATER QUALITY DATA
BEW106-TD-EV-REP-0001 Rev. 3 3 December 2013 Table A.1 Summary data for Electrical Conductivity (EC) for Suttor River Sub-catchment
Default trigger value BYSW5 BYSW6 BYSW8 BYSW9 BYSW18 FSS07 FSS08 FSS09 FSS10 FSS12 FSS16 WQS 03
n 8 17 16 20 2 461 752 15 25 32 68 381 Median (µs/cm) 168 206 161 250 182 160 1343 1102 770 497 672 647 1210 75th %ile (µs/cm) 168 228 183 441 228 179 2186 1348 1580 824 1650 942 1990
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Table A.2 Summary data for BYSW2 ANZECC 20th 80th BYSW2 Units QWQG Min Median Max n n- * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-2 3 December 2013 Table A.3 Summary data for BYSW3 ANZECC 20th 80th BYSW3 Units QWQG Min Median Max n n- * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-3 3 December 2013 Table A.4 Summary data for FSS03 ANZECC 80th FSS03 Units QWQG 20th Percentile Min Median Max n n- Dissolved Aluminium mg/L 0.055 0.010 0.010 0.010 2.200 0.090 41 22 Dissolved Boron mg/L 0.37 0.05 0.05 0.06 0.17 0.12 41 19 Dissolved Copper mg/L 0.0014/0.008* 0.0010 0.0010 0.0020 0.0060 0.0020 42 13 Dissolved Manganese mg/L 1.9 0.00 0.00 0.00 0.00 0.00 1 0 Dissolved Nickel mg/L 0.011/0.06* 0.002 0.001 0.004 0.013 0.006 42 3 Dissolved Zinc mg/L 0.008/0.05* 0.005 0.005 0.005 0.185 0.010 42 30 Total Aluminium mg/L 0.080 0.020 1.450 42.300 9.200 41 0 Total Boron mg/L 0.05 0.05 0.06 0.19 0.12 41 20 Total Copper mg/L 0.0020 0.0010 0.0030 0.0360 0.0088 42 5 Total Manganese mg/L 0.3 0.3 0.3 0.3 0.3 1 0 Total Nickel mg/L 0.005 0.001 0.009 0.079 0.022 42 1 Total Zinc mg/L 0.005 0.005 0.010 0.196 0.045 42 17 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-4 3 December 2013 Table A.5 Summary data for FSS04 80th ANZECC 20th FSS04 Units QWQG Min Median Max Percentil n n- Dissolved Aluminium mg/L 0.055 0.010 0.010 0.010 7.790 0.106 75 38 Dissolved Boron mg/L 0.37 0.05 0.05 0.07 0.16 0.10 73 32 Dissolved Copper mg/L 0.0014/0.008* 0.0010 0.0001 0.0010 0.0310 0.0020 79 43 Dissolved Manganese mg/L 1.9 0.00 0.00 0.00 0.02 0.01 32 5 Dissolved Nickel mg/L 0.011/0.06* 0.002 0.001 0.003 0.063 0.006 79 6 Dissolved Zinc mg/L 0.008/0.04* 0.005 0.005 0.005 0.048 0.005 79 64 Total Aluminium mg/L 0.110 0.010 0.510 94.700 5.174 72 3 Total Boron mg/L 0.05 0.05 0.07 0.14 0.10 73 34 Total Copper mg/L 0.0010 0.0010 0.0020 0.0790 0.0070 76 23 Total Manganese mg/L 0.0 0.0 0.0 0.5 0.1 32 1 Total Nickel mg/L 0.002 0.001 0.008 0.182 0.015 75 6 Total Zinc mg/L 0.005 0.005 0.005 0.196 0.020 75 39 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-5 3 December 2013 Table A.6 Summary data for FSS05 80th ANZECC n- FSS05 Units QWQG 20th Percentile Min Median Max Percentil n Guideline Dissolved Aluminium mg/L 0.055 0.010 0.010 0.020 2.450 0.050 31 12 Dissolved Boron mg/L 0.37 0.05 0.05 0.06 0.20 0.08 32 15 Dissolved Copper mg/L 0.0014/0.007* 0.0010 0.0001 0.0010 0.0080 0.0030 33 17 Dissolved Manganese mg/L 1.9 0.00 0.00 0.00 0.02 0.01 16 4 Dissolved Nickel mg/L 0.011/0.06* 0.001 0.001 0.002 0.007 0.004 33 15 Dissolved Zinc mg/L 0.008/0.04* 0.005 0.005 0.005 0.023 0.005 32 26 Total Aluminium mg/L 0.038 0.010 0.105 19.000 3.020 30 1 Total Boron mg/L 0.05 0.05 0.06 0.16 0.08 32 17 Total Copper mg/L 0.0010 0.0010 0.0020 0.0190 0.0060 32 15 Total Manganese mg/L 0.00 0.00 0.01 0.03 0.01 16 1 Total Nickel mg/L 0.001 0.001 0.003 0.052 0.013 31 14 Total Zinc mg/L 0.005 0.005 0.005 0.054 0.016 31 16 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-6 3 December 2013 Table A.7 Summary data for FSS14 ANZECC 20th 80th n- FSS14 Units QWQG Min Median Max n Guideline Percentile Percentile Dissolved Aluminium mg/L 0.055 0.010 0.010 0.010 1.910 0.076 33 18 Dissolved Boron mg/L 0.37 0.05 0.05 0.08 0.12 0.10 33 10 Dissolved Copper mg/L 0.0014/0.01* 0.0010 0.0010 0.0010 0.0040 0.0020 33 17 Dissolved Manganese mg/L 1.9 0.00 0.00 0.00 0.01 0.01 30 8 Dissolved Nickel mg/L 0.011/0.08* 0.001 0.001 0.003 0.007 0.005 33 8 Dissolved Zinc mg/L 0.008/0.06* 0.005 0.005 0.005 0.006 0.005 33 32 Total Aluminium mg/L 0.042 0.010 0.720 30.6 4.720 33 4 Total Boron mg/L 0.06 0.05 0.08 0.54 0.12 33 6 Total Copper mg/L 0.0010 0.0010 0.0020 0.032 0.0078 33 10 Total Manganese mg/L 0.0 0.0 0.0 0.8 0.2 30 0 Total Nickel mg/L 0.002 0.001 0.007 0.068 0.014 33 6 Total Zinc mg/L 0.005 0.005 0.006 0.070 0.019 33 14 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-7 3 December 2013 Table A.8 Summary data for FSS15 ANZECC 20th 80th n- FSS15 Units QWQG Min Median Max n Guideline Percentile Percentile Dissolved Aluminium mg/L 0.055 0.010 0.010 0.010 1.490 0.072 35 24 Dissolved Boron mg/L 0.37 0.05 0.05 0.08 0.12 0.09 34 14 Dissolved Copper mg/L 0.0014/0.01* 0.0010 0.0010 0.0020 0.0050 0.0020 35 14 Dissolved Manganese mg/L 1.9 0.0 0.0 0.0 0.1 0.0 32 10 Dissolved Nickel mg/L 0.011/0.09* 0.002 0.001 0.002 0.006 0.003 35 5 Dissolved Zinc mg/L 0.008/0.07* 0.005 0.005 0.005 0.031 0.005 35 30 Total Aluminium mg/L 0.156 0.050 0.730 35.4 15.920 34 0 Total Boron mg/L 0.05 0.05 0.08 0.13 0.10 33 10 Total Copper mg/L 0.0010 0.0010 0.0025 0.0390 0.0182 34 12 Total Manganese mg/L 0.0 0.0 0.1 1.0 0.6 32 0 Total Nickel mg/L 0.003 0.002 0.005 0.072 0.025 34 0 Total Zinc mg/L 0.005 0.005 0.011 0.089 0.038 34 14 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) BEW106-TD-EV-REP-0001 Rev. 3 A-8 3 December 2013 Table A.9 Summary data for WQS05 80th ANZECC 20th WQS5 Units QWQG Min Median Max Percentil n n Dissolved Aluminium mg/L 0.055 0.040 0.010 0.090 1.430 0.220 21 2 Dissolved Boron mg/L 0.37 0.05 0.05 0.05 0.05 0.05 21 21 Dissolved Copper mg/L 0.0014/0.003* 0.0020 0.0010 0.0020 0.0040 0.0020 21 1 Dissolved Manganese mg/L 1.9 - - - - - 0 0 Dissolved Nickel mg/L 0.011/0.02* 0.002 0.001 0.004 0.016 0.004 21 1 Dissolved Zinc mg/L 0.008/0.02* 0.005 0.005 0.005 0.005 0.005 21 21 Total Aluminium mg/L 5.900 3.6 36 122 92.3 21 0 Total Boron mg/L 0.05 0.05 0.05 0.05 0.05 21 21 Total Copper mg/L 0.0070 0.0050 0.0530 0.1560 0.1000 21 0 Total Manganese mg/L - - - - - 0 0 Total Nickel mg/L 0.016 0.010 0.118 0.382 0.232 21 0 Total Zinc mg/L 0.021 0.012 0.112 0.270 0.186 21 0 * Denotes Hardness Modified Trigger Value (HMTV) as per the ANZECC guidelines (2000) Table 3.4.3 and 3.4.4. The data has been compared against this modified trigger value. ** Denotes 75th percentile for electrical conductivity (µS/cm) as per the Queensland Water Quality Guidelines (2009) TSS not recorded for this site BEW106-TD-EV-REP-0001 Rev. 3 A-9 3 December 2013