ANNUAL
ANNUAL ENVIRONMENTAL
MANAGEMENT REPORT
DURALIE COAL MINE
PLANS AND APPENDICES VOLUME
DURALIE COAL PTY LTD
4 SEPTEMBER 2008 Duralie Coal Pty Ltd Duralie Coal Mine
PLANS
Annual Environmental Management Report September2008 5 0 E 000 350
0 0 E 000 400
5 0 E 000 450
TAREE
See Figure 2 Gloucester
6 450 000 N Stratford Krambach Nablac
A.311 Craven Tuncurry Forster Wards River A.315 DURALIE COAL MINE Stroud Road
Dungog Stroud Treachery Head
Booral THE 6 400 000 N BROADWATER
Limeburners Creek
PORT STEPHENS MAITLAND
Darwin
NORTHERN Hexham TERRITORY
AUSTRALIA WESTERN QUEENSLAND AUSTRALIA NEWCASTLE SOUTH Brisbane AUSTRALIA NEW SOUTH Perth WALES GLOUCESTER 6 350 000 N BASIN Sydney Adelaide VICTORIA Melbourne 0 2000 TAS. Hobart Kilometres LEGEND
Extent Of Coal Bearing Permian Sediments DURALIE COAL PTY LTD
ANNUAL ENVIRONMENTAL MANAGEMENT REPORT
0 25 SITE LOCATION PLAN To Sydney Kilometres
October 2008 Doc. No: DC-0007-001-2008-01-Rev.1 Figure 1 9 0 E 000 390
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River
GLOUCESTER
Barrington
Gloucester River
Berrico Waukivory 6 450 000 N
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STRATFORD Creek Avon PROJECT
Craven
6 440 000 N River Myall River
Ward
Karuah Wards River Johnsons Site 15
Pikes Crossing River SC1 Site 12 Gauging Stn. M1 River 6 430 000 N
Coal
Mammy
Shaft
SC2 Ck. M2 GB1 DURALIE M3 PROJECT High Noon SC4 Creek Creek Site 11 M4 SC3 Saggers Site 9 Stroud Road M5 6 420 000 N
Site 19
Karuah Mill
LEGEND Stroud Mining Lease Boundary Surface Water Monitoring Site Gauging Board Macroinvertebrate Sampling Site DURALIE COAL PTY LTD
Sediment Core Sampling Site River
6 410 000 N ANNUAL ENVIRONMENTAL MANAGEMENT REPORT
05Booral REGIONAL MONITORING SITES Kilometres
October 2008 Doc. No: DC-0007-001-2008-02-Rev.1 Figure 2 9 0 E 000 398 E 000 400 E 000 402 E 000 404
D7 Wards 137 109 v River 6 434 000 N 1 120
118 Terreel Mammy 350
50 103 108
1 Road
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300 107
119 1 N
Chainy 100 00 121 250 o 105 rth 116 122
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Te 4 Coast d 124 a
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300 v 150 200 tts 134 250 6 430 000 N Creek e 132 99
Andersons ck 129 v u 11 13 B 27 101 1 0 18 0 98 Soil 14 135 Road 17 35 16 Monkerai 15 97 Cr Road
eek 19 59
11 Black 106 95 450 24 20
200 22 150 300 400
25 250 350 150 v 26 100 36 94
6 428 000 N v 96 29 23
Groom Creek 30 Creek D1 Hi-Vol 2
v 31 Coal e 93
h D5 Mill T 35
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0 34 v
ad
6 426 000 N Ro D4 Creek 90
Copper 0 300 37 200 15 D2 86 85
83 v er v Riv Creek LEGEND 37 37 35 D3 Mining Lease82 Boundary. Karuah 150 35 89 Dwelling
57 s v n 84
57 so 200
n Property Boundary
ill 54 h 81 150
M
Jo 200 150 100 80 Property Owned by GCL 6 424 000 N Hi-Vol 1 100
The
39 56 JO Meteorological Station
HNSO 56 Dust Gauge
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v
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150 DURALIE COAL PTY LTD
250 76
58 300 10
350 61 gerys 40 0 74 Mar Railway
Mammy 10 72 0 53 Way v 70 Creek
41 200 Creek ANNUAL ENVIRONMENTAL MANAGEMENTCreek REPORT Dingo 150
200 Saggers k
42 ree 71 Creek d 62 C oa 48 52 R 6 422 000 N st a AIR QUALITYSaggers MONITORING SITES Creek 43 o 73 C Road 77 Mill
51 10 150 15 0
North Bowdens0 0 1 46 0 October 2008ane Doc. No: DC-0007-001-2008-03-Rev.10 Figure 3 44 47 49 64 L 5 45 50 1 200 9 0 E 000 398 E 000 400 E 000 402 E 000 404
Wards 137 109 v River 6 434 000 N 1 120
118 Terreel Mammy 350 103 108
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200 Flat Johnsons Creek v Terreel 104 150 126 3 111 123 100 110 125 112 126 200 124 Johnsons River River Road v 4 Coast Tea 124
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11 Black 106 95 450 24 20
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v 31 Coal 93
Mill The 35 Shaft
32 88 100 100 92 8 87 33 150 Creek Mine 34 v
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34 v
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Copper
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v v River
Creek 37 37 35 LEGEND82 Karuah 150 35 89 57 Mining Lease Boundary. v 84 57 200 54 Dwelling 81 150
Mill
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The
39 56 JOHNSONS Property Owned by GCL 56
100 150 250 Noise Monitoring Sites 79 78 55 300 200 60 River
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v
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N1 150 DURALIE COAL PTY LTD
250 76
58 300 AS1100 40 350 61 74 Margerys Railway Mammy 100 53 72 Way v 70 Creek
41 200 Creek ANNUAL ENVIRONMENTAL MANAGEMENTCreek REPORT Dingo 150 AAS1
200 Saggers
42 71 Creek 62 Creek 48 52 Road 6 422 000 N NOISESaggers MONITORING SITES Creek 43 73 Coast Road 77 Mill
51 100 150 150 North Bowdens100 Doc. No: DC-0007-001-2008-04-Rev.1 Figure 4 44 46 47 49 64 OctoberLane 2008 45 50 150 200 9 0 E 000 398 E 000 400 E 000 402 E 000 404
Wards 137 109 v River 6 434 000 N 1 120
118 Terreel Mammy 350
50 103 108
1 Road
117 Wards 200
300 107
119 1 N
Chainy 100 00 121 250 o 105 rth 116 122
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Flat Johnsons Creek v Terreel 104 150 126 3 111 123 1 110 125 0 0 112 126 200 124 Johnsons River River Roa v
Te 4 Coast d 124 a
6 432 000 N 113 100
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300
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y 102 100
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Andersons ck 129 v u 11 13 B 27 101 1 0 18 0 98 Soil 14 135 Road 17 35 16 Monkerai 15 97 Cr Road
eek 19 59
11 Black 106 95 450 24 20
200 22 150 300 400
25 250 350 150 v 26 100 36 94
6 428 000 N v 96 29 23
Groom Creek 30 Creek
v 31 Coal
e 93 h Mill T 35
Sha 88 0
32 0 1 100 ft 92 8 87 33 150 C ine reek M 34 v
1 35
0 91
0 34 v
ad
6 426 000 N Ro
Creek 90
Copper 0 300 37 200 15 86 85
83 v er v Riv
Creek 37 37 35 LEGEND82
Karuah 150 35 89 Mining Lease Boundary.
57 s v n 84
57 so 200
n
ill Dwelling 54 h 81 150
M
Jo 200 150 100 80 6 424 000 N 100 Property Boundary
The
39 56 JO
HNSO Property Owned by GCL 56
1 150 250 0 Blast Monitoring Sites 0 NS 79 78 55 300 200 60 River
Bucketts v
v
200
150 DURALIE COAL PTY LTD
250 76
58 300 10
350 61 gerys 40 0 74 Mar Railway
Mammy 10 72 0 53 Way v 70 Creek
41 200 Creek ANNUAL ENVIRONMENTAL MANAGEMENTCreek REPORT Dingo 150
200 Saggers k
42 ree 71 Creek d 62 C oa 48 52 R 6 422 000 N st a BLAST/VIBRATIONSaggers MONITORING SITES Creek 43 o 73 C Road 77 Mill
51 10 150 15 0
North Bowdens0 0 1 46 0 October 2008ane Doc. No: DC-0007-001-2008-05-Rev.10 Figure 5 44 47 49 64 L 5 45 50 1 200 1. SEJON NO 4 PTY LTD 54. VR &EK SCHULTZ 105. RS MUDFORD 3. KV & PM HOWARD 55. IK & MJ SCHULTZ 106. RS & R MUDFORD 4. BV & PO HOWARD 56. EK & VR SCHULTZ 107. DJ ROBERTSON 5. GR & GR WEISMANTEL 57. G SCHULTZ 108. WA & JA THOMSON 6. SR & J HOGEVEEN 58. TI &FHS WOOD 109. HUNTER WATER 7. ED & LM HOLMES 59. HATTAM PL CORPORATION 8. CW & JI EDWARDS 60. JS & KA GIBSON 110. AG TERSTEEG 9. PWM MOYLAN 61. MH & EV ELFICK 111. GW LEWIS & AJ MOORE 11.PWM&BD&GO&MJ 62. BJ & MC GAY 112. TJ SOMERVILLE & CD MOYLAN & SCM NEWTON 63. AW RAINE & T HILLEARD MARTIN 13. GLOUCESTER COAL LTD 64. KB & JN FARNHAM 113. RJ BATHGATE & ML LEVEY 14. T JENSEN 65. CA BOWDEN 114. SHULGIN INVESTMENTS 15. S WHITE 66. S & AF VASDA OTY LTD 16. GLOUCESTER COAL LTD 70. TE RUMEEL 116. GLOUCESTER COAL LTD 17. MJ &CA MAHONY 71. HJ GILLARD 117. AE & CA HOWE 18. GLOUCESTER COAL LTD 72. B CLAYTON 118. SW DAVIS 19. BL BEAVIS 73. SW & SR GRAY 119. GLOUCESTER COAL LTD 20. MS JUTTNER 74. Crown Land 120. WR KERSLAKE 22. GLOUCESTER COAL LTD 75. AM MOKEEFF 121. KR MUDFORD 23. PG & KA MADDEN 76. P TRENCHEV 122. RS MUDFORD 24. BMG & P. MOYLAN & 77. ROAD 123. K MacFARLANE S.NEWTON 78. RN & TE RUMBEL 124. RJ WEISMANTEL AND 25. GLOUCESTER RURAL 79. GJ THOMPSON COMPANY PL LANDS PROTECTION BOARD 80.BR&GJ&KG&KJ&WJ 125. KM & DB HOLLOWAY 26. M MADDEN THOMPSON 126. GLOUCESTER COAL LTD 27. GLOUCESTER COAL LTD 81. I MELLAR 127. AR ROBSON 28. GREAT LAKES COUNCIL 82. MA HOCKINGS & CH 128. HL & MR HAMANN & 30. JR GORTON WILLCOX PIXALU PL 31. DJ WIELGOSINSKI 83. LS MILLER 129. WL RELTON 32. DH & SW OWENS 84. NE HITCHCOCK & EE 130. AJ & RM BAILEY 33. MA BRAGG COLDHAM 131. AJ FISHER-WEBSTER 34. JI EDWARDS 85. DG HUTCHISON 132. J WEISMANTEL 35. GLOUCESTER COAL LTD 86. P & ME KENNEY 133. MA & JM GUIDICE 36. RS DOHERTY 87. CN & SD STEPHENSON 134. T &K&VZULUMOVSKI 37. DJ MCANDREW 88. TRJ & B HOPE 135. DR & BM HARE SCOTT 39. AJ & AL DANIEL 89. WJ THOMPSON 136. D & M RASBURN 40. RDK & NL WILLIAMS 90. TR WATERER 137. PACIFIC PROPERTY 41. ED SANDERS 91. B GILBERT INVESTMENTS LTD 42. HR & DA MOOREHOUSE 92. M & R GUBERINA 43. JV BRERETON 93. L & KM YOUNG 44. CS PARKER 94. L & RK PAUL 45. IG WILSON 95. DM LOWREY 46. JS & KL BRATFIELD 96. GORTON TIMBER CO. 47. DE ALLEN LIMITED 48. MC JONES 97. TJ LORD 49. DC CARROLL 98. DP PICKLES 50. PG & LJ BILLETT 99. PJ AYLIEFE & LA SMYTH 51. RJ & SJ WOODLEY 100. DUZMEN PTY LTD 52. SM, JAM,MSC & TRIGG, M 101. RJ GORTON JAMES AND 102. AT GORTON BJ HOLLAND 103. VS & RM EDWARDS 53. SJ & JE LYALL 104. PG SPENCER
DURALIE COAL PTY LTD
Landholdings not shown on Figs 3,4 and 5 as they are ANNUAL ENVIRONMENTAL MANAGEMENT REPORT under the Title Block and Legend LAND OWNERS
October 2008 Doc. No: DC-0007-001-2008-06-Rev.1 Figure 6
9 0 E 000 399
0 0 E 000 400 0 0 E 000 401
North Mammy
Johnson
120 C Creek oa
s t
Road
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140 s 00 1 o n
s 6 428 000 N 60
80 River 60
80 80 80 R
ailway
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Eastern Diversion Channel 6 427 000 N
Main Creek 120
0 Diversion10 100
120 80 Active Mining 80 SW4 Void
100 120
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100
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100 SW3 60
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160 LEGEND 140 120 100 Mining Lease Boundary
80 Sediment Storage Areas
e 60
80 100
Min 140
SD3 120
SD2 160 SD1 SD4
B DURALIE COAL PTY LTD u cke
tts ANNUAL ENVIRONMENTAL MANAGEMENT REPORT W
a y SEDIMENT STORAGE AREAS 0 500
Metres October 2008 Doc. No: DC-0007-001-2008-07-Rev.1 Figure 7
9 0 E 000 399
0 0 E 000 400 0 0 E 000 401
North Mammy
Johnson
120 C Creek oa
s t
Road
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140 s 00 1 o n
s 6 428 000 N 60
80 River 60
80 80 80 R
ailway DB7W 0
0 1
80
SW2 Upstream Eastern Diversion Channel 6 427 000 N
Main Creek 120 0
Diversion10 DB1W 100
120 80 Active Mining 80 DB3W Void
100 120 DB6W
ML 1427
SW4 60 BH4BW
0 140
4
120 100m. 100 1 100 80 Dumping DB2W BH5W SI1W 100 GB1 SI2W Main 80 6 426 000 N SW3 100 60
80
SI3W Dam 80
0 0 8 12 BH1BW SW2 (RC)
100 SW2 Plant and DB4W Infrastructure BH2W Area d SW6 oa 0 R 2
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120 6 425 000 N
14
80 16
0
0
60 Access 60
160 LEGEND SW1 140 120 100 Mining Lease Boundary 100m. 80 Surface Water Monitoring Site
e 60
80
100 Ground Water Monitoring Site
Min
140 120 160
B DURALIE COAL PTY LTD u cke
tts ANNUAL ENVIRONMENTAL MANAGEMENT REPORT W
a y SURFACE AND GROUNDWATER 0 500 LOCAL MONITORING SITES
Metres October 2008 Doc. No: DC-0007-001-2008-08-Rev.1 Figure 8
0 0 E 000 400
0 0 E 000 401
9 0 E 000 399
North Mammy Legend Area 1 Demountables Johnson
Workshops
Area 2 - Conveyors
C Creek Area 3 - Carbonaceous Removal oast
Area 4 - Total CHPP Road Area 5 - Rail Siding
J Area6-Workshop Apron o h
n s Area 7 - Haul and Access Roads o n s 6 428 000 N Area 8 - Concrete Pads
Area 9 - Car Park River
Area 10 - Unshaped Overburden Dumps Railway Area 11 - Shaped Overburden Dumps Area 12 - Successful Rehabilitation
Area 13 - Active Mine Voids
Area 14 - Dirty Water
Area 15 - Clean Water Area 16 Main Creek Diversion Eastern Diversion Eastern Diversion Channel 6 427 000 N Channel Tempory Diversion Dam Main Creek Diversion Area 17 - Prill Storage
Area 18 - Emulsion Storage Active Mining Area 19 - Explosives Magazine Void
ML 1427
6 426 000 N Main Dam
Explosives Magazine
Plant and Infrastructure Area
oad R
ss 6 425 000 N
Acce
Mine
DURALIE COAL PTY LTD
ANNUAL ENVIRONMENTAL MANAGEMENT REPORT 0 500
Metres AREAS DISTURBED AND REHABILITATED
Aerial Photography - April 2008 October 2008 Doc. No: DC-0007-001-2008-09-Rev.1 Figure 9
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ML 1427 Waste Emplacement
6 426 000 N Main Dam
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oad R
6 425 000 N ss
Acce
Mine
DURALIE COAL PTY LTD
ANNUAL ENVIRONMENTAL MANAGEMENT REPORT 6 424 000 N 0 500 AREAS DISTURBED AND REHABILITATED Metres (From Aerial Photograph - April 2008)
Aerial Photography - April 2008 October 2008 Doc. No: DC-0007-001-2008-010-Rev.1 Figure 10 Mine viewed across Irrigation Dam.
Waste Emplacement from Weather Station.
DURALIE COAL PTY LTD
ANNUAL ENVIRONMENTAL MANAGEMENT REPORT
PHOTOGRAPHS
October 2008 Doc. No: DC-0007-001-2008-011-Rev.1 Figure 11 Duralie Coal Pty Ltd Duralie Coal Mine
APPENDIX I
AMENDED OR NEW APPROVAL AND LICENCE CONDITIONS ISSUED DURING THE REPORTING PERIOD
Annual Environmental Management Report September2008 Duralie Coal Pty Ltd Duralie Coal Mine
ENVIRONMENT PROTECTION LICENCE VARIATION
Annual Environmental Management Report September2008
Duralie Coal Pty Ltd Duralie Coal Mine
MINING OPERATIONS PLAN AMENDMENTS
Annual Environmental Management Report September2008
Duralie Coal Pty Ltd Duralie Coal Mine
APPENDIX II
ENVIRONMENTAL MONITORING DATA
Annual Environmental Management Report September2008 Duralie Coal Pty Ltd Duralie Coal Mine
BIOLOGICAL MONITORING
Annual Environmental Management Report September2008 Duralie Coal Project - Biological Monitoring of the Streams Adjacent to the Duralie Coal Mine Study 1, Survey 12, September 2007.
INVERTEBRATE IDENTIFICATION AUSTRALASIA 51 Panorama Parade, Panania, NSW 2213, Phone (02) 6771 1458 Mobile 0412 372 388 Email: [email protected] or [email protected] Table of Contents
Executive Summary ...... 3 Introduction...... 4 Study Area and Sampling Sites...... 4 General Description...... 4 Mammy Johnsons River ...... 6 Karuah River...... 6 Diversion Drain Dam No.2...... 6 September Site Images ...... 6 Methodology...... 8 Macroinvertebrate Sampling...... 8 Identification ...... 9 Data analysis ...... 9 Silt Tolerant Species...... 10 Physico-Chemical Data ...... 10 Results ...... 10 Macroinvertebrate Data ...... 10 Silt Tolerant Species...... 17 Site DDD2...... 18 Physico-Chemical Data ...... 19 Site DDD2...... 20 Discussion...... 22 Acknowledgements ...... 23 References...... 23 Appendix 1...... 25
2 Executive Summary Duralie Coal Pty Ltd commenced the establishment of an open cut coalmine in 2002, adjacent to the Mammy Johnsons River, upstream from the township of Stroud Road. As part of Duralie Coal’s environmental monitoring program, Invertebrate Identification Australasia was commissioned to conduct biological monitoring of the streams near the mine including portions of the Mammy Johnsons and Karuah Rivers. This report is the twelfth environmental assessment of the aquatic ecosystems associated with the Duralie Mine and is the eleventh since the mine became operational.
Six sites were sampled on the 12th September 2007 for aquatic macroinvertebrates and water quality using rapid assessment techniques. A total of 76 species representing 76 genera were recorded in 52 families. In addition, five biological indices were used to determine the condition of the streams in and adjacent to the Project area.
The results of the current survey indicate that the prevailing conditions are generally similar to those recorded in previous years and show no evidence of any adverse effects on the aquatic macroinvertebrate community and, therefore, the river ecosystem, as a result of the mine’s operations. In addition, three significant rainfall events have occurred recently, two in June and one in August, which have contributed to a major improvement in flow and ecosystem health. Overall, the biodiversity values and the environmental indices were increased from the March 2007 survey, but were comparable to or higher than those observed in the same period last year. The data indicates that all sites have very healthy macroinvertebrate communities with little variation in species composition, environmental condition or water quality parameters outside of seasonal fluctuations.
The environmental monitoring of the water quality and the aquatic ecosystem within the Diversion Drain Dam (DDD2) above the mine water storage dam (west of the mining operation) is continuing. This monitoring program has been established to monitor any impacts of potential saline run-off from the irrigation of saline mine water onto the ridges and slopes surrounding the mining area upon water quality and/or the local macroinvertebrate community. Results from the eighth survey of the dam indicate that the electrical conductivity is still low, and there is a diverse aquatic community established and continuing to develop consisting increasingly of disturbance sensitive taxa. Macrophytes are continuing to become established, which will add to the diversity of habitats present in the dam and will, over time, assist with an increase in diversity and community complexity.
3 Introduction Duralie Coal Pty Ltd commenced an open cut coalmine operation in 2002, adjacent to the Mammy Johnsons River, upstream of the township of Stroud Road. As part of Duralie Coal’s environmental monitoring program, Invertebrate Identification Australasia was commissioned to conduct biological monitoring of the streams near the mine. This report provides the twelfth environmental assessment of the aquatic ecosystems of Mammy Johnsons River and the Karuah River above the junction with Mammy Johnsons River. It also reports on the seventh water quality and aquatic ecosystem survey of the Mine’s Water Diversion Drain Dam No. 2 (DDD2).
Aquatic macroinvertebrate communities have been used as a reliable and cost effective environmental indicator of stream condition for more than 20 years across Australia. These communities have long been recognised as being ideally suited for the assessment of river health and condition as they are diverse, occupy every niche within a water body including the riverbed, water column and surface, are one of the major contributors to the processing of energy through a river system and responds directly to physico-chemical changes within the aquatic environment. The composition of this community consists of a range of predators, grazers, shredders and filter feeders and reliably reflects both natural and threatening processes operating within a catchment. The ubiquitous distribution and specific habitat requirements of each component at both the species and community levels, enables the use of their diversity as an indicator of ecological disturbance within a catchment.
The environmental monitoring of the water quality and aquatic ecosystem within one of the Mine’s water dam diversion drain dam located to the west of the mining operation continues. This monitoring program has been established to monitor for any changes to the diversion drain dam water quality and/or the local macroinvertebrate community as a result of potential saline run-off from irrigation onto the ridges and slopes surrounding the mining area.
Study Area and Sampling Sites General Description The Duralie Coal Mine is situated approximately 10 km northeast of the township of Stroud Road on the western side of Mammy Johnsons River on the New South Wales central coast. The Mammy Johnsons River and the Karuah River are the two major tributaries of the Karuah River system. The Mammy Johnsons River and the Karuah River below the junction with Mammy Johnsons are the only major watercourses that would potentially be affected by operations from the Duralie mine.
Site code Site name and description Grid Reference M1 Above mine area, near gauging station. 400607N, 6430921E M2 Downstream of M1 and above the mine area 401262N, 6427007E M3 Downstream of M2 and below mine area 401463N, 5425640E Downstream of M3 and below mine area. 30m west of M4 400388N, 6422495E Johnsons Ck Rd M5 Karuah River at Stroud Road on Stroud Rd/Dungog Road 401462N, 6425639E DDD2 Diversion Drain Dam 2 above Mine Water Storage Dam 387750N, 6424400E
Table 1. Sampling sites.
4 Figure 1. Map showing the location of the five monitoring Sites M1 - M5 and their position relative to the Duralie and Stratford mine sites.
The region was experiencing a continuation of below average rainfall prior to June 2007, which had prevailed in the region for the last four-five years. This decrease in rainfall has provided base (low) river levels interspersed with some minor ‘flushes’ or flood events. In
5 June the Karuah and Mammy Johnsons River catchments (as well as most of the Hunter Region and Central Coast) experienced a major rainfall event resulting in a significant flood going down the Karuah and Mammy Johnsons Rivers, which raised river levels by over five metres. This flood was followed by a smaller but still substantial rainfall event around the 19th of August which resulted in a flood that was still in the process of returning to normal flow levels at the time of sampling. The higher water levels at all sites, resulted in the river being turbid, most pools having current and some areas of riffles being inaccessible due to strong currents.
Five sites were selected (Figure 1, Table 1) from amongst the sites initially included in the then proposed mine’s Environmental Impact Study (prepared by Woodward Clyde). These sites were sampled on the 12th September 2007 for aquatic macroinvertebrates and water quality using rapid assessment techniques. Four sites are located along the Mammy Johnsons River, with two are located above the mine (Sites M1 and M2) and two below the mining area (Sites M3 and M4). One site is located on the Karuah River (Site M5) at Stroud Road, upstream of the junction with Mammy Johnsons River. Site M3 has been relocated approximately 50m downstream from the original site in order to incorporate a larger, stony riffle section, a habitat that was previously absent from Site M3.
Mammy Johnsons River The Mammy Johnsons River is a small meandering coastal stream that passes through predominantly heavily wooded native forest with a smaller amount of cleared, grazing country found mainly in the lower sections. For a more complete description of each of the study sites refer to previous reports (Reports 1-11). During this survey the pools and riffles were quite turbid due to the floods and had small amounts of green filamentous algae at Site M4 at the open sunny end of the riffle. There was no apparent deposition of silt as all hard surfaces had been extensively scoured by the two flood events.
Karuah River The Karuah River joins the Mammy Johnsons River below Stroud Road and possesses the same river geomorphological characteristics and substrate composition as that of Mammy Johnsons River. The Karuah River, however, is a larger river of approximately double the water volume of the Mammy Johnsons and therefore, has higher velocities and much larger (courser) substrate size in the riffle zones. The water appeared turbid as in the Mammy Johnsons River. There was no green filamentous algae in the Karuah River during this survey; and the cobbles and boulders in the riffles had been obviously scoured clean of any algae, silt or detritus.
Diversion Drain Dam No.2 A sixth site was selected within a diversion drain dam above the mine water storage dam (west of the mining operation) in order to be able to assess whether saline water runoff was occurring from the irrigation of mine water onto the ridges and slopes to the west of the mining operation. The Diversion Drain Dam No. 2 (Site DDD2) is one of four dams that have been recently established to collect rainfall runoff from the slopes and hillsides surrounding the mine as well as mine irrigated water (which has moderate levels of salinity) in order to control the rate at which runoff enters the drain. The development of the foreshore riparian zone and macrophyte beds are continuing with the natural colonisation of the near shore zone by sedges and floating macrophytes.
September Site Images The following twelve photographs (Photos 1 - 12) of Sites M1 - M5 and DDD2 were taken during the current survey and illustrate the prevailing conditions of the two rivers and dam as well as the extent of the riparian zone observed at each site. Note that the water levels are higher in the river than the previous survey but consistent in the dam with the previous survey.
6 1 2
Site M1, viewed downstream (1); viewed upstream (2) (Taken September, 2007).
3 4
Site M2, viewed downstream (3); viewed upstream (4) (Taken September, 2007).
5 6
Site M3, viewed downstream (5); viewed upstream (6) (Taken September, 2007).
7. 8
Site M4, viewed downstream (7); viewed upstream (8) (Taken September, 2007).
7 9 10
Site M5, viewed downstream (9); viewed upstream (10) (Taken September, 2007).
11 12
Site DDD2, viewed east (11); viewed west (12) (Taken September, 2007).
Methodology Macroinvertebrate Sampling Each site was sampled using two standardised methods outlined in the River Bioassessment Manual (Anon. 1994) and the NSW AUSRIVAS Sampling and Processing Manual (2000). The results are presented in Table 4.
The first method involves the rapid assessment techniques employed in NSW AUSRIVAS Sampling and Processing Manual (2000). In this survey two habitats were sampled, 1) pool edge and 2) riffles.
1a) Pool edges are sampled with a macroinvertebrate kick net that is drawn through the water over the substrate starting from 1.5m off the edge and working in towards the bank along the edge in a rapid motion for approximately 10m. In order to sample a larger area of a river reach, smaller samples of approximately 1-2m are taken along the length of the pool to a maximum combined length of 10 metres.
1b) Riffles are sampled with a kick net held in the riffle with the net extending downstream while the substrate directly upstream is agitated with either hands or feet. The sampling strategy is the same as for edges, where, in order to sample a larger area of the riffle zone, small samples of approximately 1-2m are taken along the length of the riffle to a maximum combined length of 10 metres. Care needs to be taken to turn over boulders and to clean boulders and cobbles with the hands to remove encrusting animals. The samples from each habitat are combined in the results to give a comprehensive species list for the whole site.
8 2) The second method involves targeted opportunistic sampling of macroinvertebrates from a variety of habitats and substrates, when available. Habitats sampled may include: • logs and wood from within pools, pool edges and riffles; • large rocks and boulders from within pools and riffles; • kick net sweeps through macrophyte beds and • kick net sweeps under bank overhangs.
All samples are preserved in the field with 100% ethanol and returned to the laboratory for sorting and identification.
Identification All samples were sorted under a stereomicroscope and stored in 70% alcohol. Specimens were identified to genus where possible, (except for Chironomidae, Oligochaeta and Platyhelminthes which are identified to family/subfamily), using a combination of current taxonomic works and keys and comparison with voucher specimens in the reference collections of Invertebrate Identification. Identification references included Williams (1981) and the taxonomic identification series produced by the Murray Darling Freshwater Research Centre.
Data analysis SIGNAL HU97B (Chessman et al., 1997). SIGNAL is an acronym for ‘Stream Invertebrate Grade Number - Average Level’, and is a biotic index of pollution tolerance or sensitivity (see Table 2). Each invertebrate family is awarded a pollution sensitivity rating from 1 to 10, with 10 being the most sensitive species, i.e. species only found in pristine/high water quality locations. These values are summed for all families present that have been allocated a SIGNAL value and divided by the number of families to provide an average grade for the stream. The SIGNAL values are between 1 and 10 with values equal to or greater than 6 representing clean water (good); 5.0-5.9 doubtful quality (fair), possibly mild pollution (poor) 4.9 – 4.0 and less than 4, probable severe pollution (very poor).
The SIGNAL HU97B is an updated version of the original SIGNAL 95 Chessman (1995) index and has been used from the beginning of the Duralie surveys for consistency. The original SIGNAL index was developed in the lower Blue Mountains whereas the 97 version was developed for the Hunter Valley and therefore is a more appropriate measure of stream environmental condition for this area.
SIGNAL -HU97B Probable water quality status
>7 Excellent 6-7 Good 5-6 Fair 4-5 Poor <4 Very poor
Table 2. Interpretation of water quality status using SIGNAL -HU97B scores (Chessman et al., 1997).
EPT Richness. The second index is based on three groups of insects that contain a majority of pollution sensitive taxa (Lenat, 1988). All species of Ephemeroptera, Plecoptera and Trichoptera are identified and then the number of distinct taxa counted (see Table 3). The EPT measure is based on the observation that the majority of taxa in these groups are particularly pollution sensitive. This feeding guild is important to the ‘health’ of an aquatic
9 ecosystem because they break down the allochthonous material (leaves and twigs) that falls in or is washed into streams. Coarse allochthonous matter is the primary energy source for most aquatic ecosystems. By breaking down this material, energy is transferred from one feeding group to another thereby increasing the food resources for other feeding groups and in turn increasing biodiversity. An absence or low number of these groups, through increases in pollution and/or disturbance, results in decreased energy processing and biodiversity.
EPT genus richness Probable condition of macroinvertebrate community
>6 Healthy 5-6 Slightly impaired 3-4 Moderately impaired 1-2 Severely impaired 0 Grossly impaired
Table 3. Interpretation of the EPT genus richness scores (Besley et al., 1998).
Number of Families. All macroinvertebrate families are separated and counted. The number of families present generally decreases with decreasing water quality and is used as a comparative measure of community change over time.
Functional Feeding Groups. Ratio of shredder taxa to total number of taxa. As with Numbers of Families the higher the ratio of shredders the better the water quality and is used as a comparative measure of community change over time.
Silt Tolerant Species The Environmental Management Plan of the Duralie Mine states that the aquatic fauna assemblages need to be assessed for silt tolerant fauna, as the presence of such fauna can provide an indication of the degree of heavy sediment pollution. The main indicator families are the Dugesiidae, Lymnaeidae, Ancylidae, Planorbidae, Psephenidae, Chironomidae, Caenidae, Pyralidae and Ecnomidae.
The silt tolerant taxa values are best examined against the total number of taxa sampled from each site i.e. the silt tolerant ratio, as the variation of values is significantly reduced compared with examining the number of taxa alone. This index is used as a comparative measure of community changes over time.
Physico-Chemical Data Physical and chemical parameters were measured at each site in situ and included temperature, conductivity and pH. Due to the failure of our standard water quality sampling equipment all parameters were taken by James Benson, Environmental Officer for the Duralie Mine. Dissolved oxygen was not measured during the current survey. However, as the river was flowing above normal we assumed that the dissolved oxygen levels were well above minimum acceptable limits for all sites as they were satisfactory during most of the extended low flow periods observed in previous surveys. The results are presented in Table 5.
Results Macroinvertebrate Data A total of 76 genera in 52 families were recorded during the current survey. Sites M1 and M2 on the Mammy Johnsons River recorded the highest diversity with 38 and 37 genera, respectively. These values are the same as the values for these two sites from the previous
10 survey, whereas the other sites were comparable for the same period last year. Site M3 recorded the lowest diversity from the river sites with 29 genera. However, this is comparable with previous September surveys. Site DDD2 had the second highest recorded diversity for this site with 29 genera, which is two more than the September 2006 survey and included nine taxa not found at the other sites sampled.
Survey 11 M1 M2 M3 M4 M5 DDD2 SIGNAL - HU97B 5.9 6.1 6.0 6.7 6.2 5.1 No of Families 31 32 23 26 29 23 No of Genera 38 37 29 32 34 29 EPT 11 13 11 10 13 4 EPT ratio 0.29 0.41 0.48 0.38 0.45 0.17 Shredder Ratio 0.45 0.49 0.45 0.5 0.53 0.24 Silt Tolerant Taxa 4 5 3 6 5 5 Silt Tolerant Taxa Ratio 0.11 0.14 0.1 0.19 0.15 0.17
Table 4. Summary Table of numbers of genera, families and indices. A full list of the taxa found is presented in Appendix 1.
The variation in the number of genera observed at each site since September, 2002 is illustrated in Figures 2-3. The graph of biodiversity values ( = number of observed genera) recorded for the current survey shows an overall increase for all sites compared with the March, 2007 survey, except for Sites M3 and M4, which showed a decrease in value since the last survey. However, a comparison with the previous surveys indicates that the biodiversity values recorded at Sites M3 and M4 in Survey 12 were lower but comparable with the last two to three years. The pattern of variation along the river (Figure 3) shows a lowering in diversity downstream towards Site M3 on the Mammy Johnsons River, followed by a slight increase downstream to Site M4. These values have remained relatively consistent since Survey 3 in 2003 and are comparable and/or higher than the same period during 2004 and 2005.
Aquatic Biodiversity
50 M1 45 M2 40 M3 35 30 M4 25 M5 20 DDD2 15 No. of Genera 10 5 0
02 3 04 4 05 6 r- r- r-07 p- ep-0 ep-0 a Se Mar-03 S Ma Sep-0 Ma Sep-05 Mar-06 S M
Figure 2. The observed variation in the number of genera recorded for all sites since September, 2002.
11 Aquatic Biodiversity 03/09/2002 50 28/03/2003 45 25/09/2003 40 19/03/2004 35 03/06/2004 30 21/09/2004 10/03/2005 25 15/09/2005 20 07/04/2006
No. of Genera No. of 15 19/09/2006 10 07/03/2007 5 12/09/2007 0 M1 M2 M3 M4 M5 DDD2
Figure 3. The observed variation in the number of genera recorded for all sites since September, 2002.
The condition indice (SIGNAL) values differed from the biodiversity values by showing an increase or stable condition in values at all sites compared with the previous survey and an increase with the same period for the last four years. The values ranged from 5.9 to 6.7 for the river sites. Sites M2 and M3 had similar values of 6.1 and 6.0 respectively while Site M4 recorded the highest value of 6.7. Site M1 recorded the lowest value of the river sites with a value of 5.9, which is the second highest value recorded for this site (the lowest was 5.0 recorded on the 3rd June 2004). The lowest overall value recorded was 5.1 for Site DDD2, which is the highest value recorded for this site since sampling begun. A significant feature of these results is the consistently high values recorded along the surveyed length of the Mammy Johnsons River and its comparative similarity to the Karuah River site. These values indicate that Sites M1 to M5 were in fair to good condition. Even though the SIGNAL values appear to suggest a lower condition rating compared with the other indices, the high species diversity and relatively number of EPT taxa compared with the silt tolerant taxa indicate that the sites are in good to excellent condition.
The variation in SIGNAL values along the river and the diversion drain since September, 2002 is illustrated in Figures 4-5. Each survey, so far, has shown the same pattern with little overall variation along the river and a similar pattern over time at all sites. The current survey’s results are generally higher than those of the previous survey. However, they are similar to the previous spring surveys from 2003 to 2006. This signifies that the community composition has remained very stable in the number of pollution / disturbance sensitive taxa, particularly within the EPT group, even with the impact of the prolonged years of drought leading to prolonged periods of low flow. The higher SIGNAL values and lower silt tolerant taxa values at the top end of the Mammy Johnsons River catchment reflects the slightly different geomorphology and flow rates i.e. higher flow and courser substrates, while the Karuah River had more favourable conditions for the EPT group of organisms. Even though the number of taxa is generally less compared with the Mammy Johnson’s sites the condition index values of the taxa present (higher numbers of high value EPT taxa and lower numbers of lower value silt tolerant taxa) results in higher scores. The overall results of the current survey show an increase in river condition compared with the March 2007 survey (Survey 11). The SIGNAL index is also calculated for the dam site (Site DDD2), although it is not
12 really appropriate for this particular site (a standing water system) as it was originally developed for flowing river systems. Nonetheless, it is still useful in mapping the changes in the community structure of the dam over time. The results indicate a small increase in condition compared to those observed in Survey 11. However, it is still an improvement on all of the previous September surveys.
SIGNAL 97 8 7 M1 6 M2 5 M3 4 M4 3 M5 DDD2 2 SIGNAL Value 1 0
2 3 4 5 6 7 -0 -0 -0 -0 -0 -0 ep ep ep ep ep ep S S S S S S
Figure 4. The observed variation in the SIGNAL-97 values for all sites since September, 2002.
The EPT index values (see Figure 6) were similar at all sites for the same period last year. The values indicate an increase at all sites in EPT taxa since the last survey period. This trend is the same as the previous two surveys at all sites indicating a natural seasonal fluctuation in biodiversity where many species have large mature juveniles through the spring/early summer period. These results suggest that the pronounced increase in values has occurred as a result of seasonal trends.
The EPT values are best examined against the total number of taxa sampled i.e. the EPT ratio, as the variation of values is usually significantly reduced. Figure 7 illustrates the EPT ratio for all the sites and among the eleven surveys to date. The ratio also recorded a significant increase in values for all sites compared with the previous survey ranging from 0.29 to 0.48 for Sites M1 and M3 respectively. Therefore, Site M3 had the highest proportion of EPT taxa while Site M1 had the lowest. The EPT ratio values clearly separate the three major habitats with the Karuah River (Site M5 – the higher flow system) recording a relative high value, the Mammy Johnsons River (the lower flow and finer sediments and courser substrate system) sites have very similar values and Site DDD2 (the non-flowing system) recorded the lowest value. However, the recent high flow events have blurred the boundaries between Site M5 and the rest of the Mammy Johnsons River sites with Site M3 overlapping Site M5. The differences are quite noticeable during periods of low flow when average flow velocities are higher in the Karuah River with larger substrate types.
The shredder ratio values are illustrated in Figure 8 and are similar to the EPT index with a general increase in values, which are comparable to the pre 2005 observed values. All sites, except Site M5, were higher than the previous survey and ranged from 0.45 at Sites M1 and M3 to 0.53 at Site M5. Site M5 showed a comparable number of shredders with the March 2003 survey.
13 SIGNAL 97 03/09/2002 8 28/03/2003 7 25/09/2003 19/03/2004 6 03/06/2004 21/09/2004 5 10/03/2005 4 15/09/2005 07/04/2006 3 19/09/2006
SIGNAL Value SIGNAL 2 07/03/2007 12/09/2007 1
0 M1 M2 M3 M4 M5 DDD2
Figure 5. The observed variation in the SIGNAL-97 values for all sites since September, 2002.
No. of EPT taxa
20 18 16 M1 14 M2 12 M3 10 M4 8 M5 6 DDD2 4
No. each at taxa site of 2 0
3 3 5 5 7 -0 -0 -0 -0 -07 0 r p r p r e ar-04 e ar-06 ep- Sep-02Ma S M Sep-04Ma S M Sep-06Ma S
Figure 6. The observed variation in the EPT values for all sites since September, 2002.
The most significant change in the community found during this survey was the apparent increase in the number of grazer species (including the EPT group of taxa) compared with the apparent lowering of silt tolerant taxa. The common and consistently recorded taxa belong to the following groups: the coleopteran family Elmidae (beetles); the dipteran family Orthocladinae (midges); the ephemeropteran families Leptophlebiidae (mayflies), the plecopteran family Grypopterygidae (stone flies) and the trichopteran families Hydropsychidae, Philopotamidae (caddis flies).
14 EPT Ratio 0.6
0.5 M1 0.4 M2 M3 0.3 M4 M5 0.2 DDD2 EPT Ratio Value EPT Ratio 0.1
0
02 03 03 04 04 05 05 06 06 07 07 - r- - r- - r- - r- - r- - ep a ep a ep a ep a ep a ep S M S M S M S M S M S
Figure 7. The observed variation in the EPT ratio values for all sites since September, 2002.
The considerable reduction in the presence of dipterans at all sites including the subfamilies of the Chironomidae (particularly the Orthocladinae) are indicative of a major disturbance to the environment leading to a decrease in numbers. The chironomid subfamily Orthocladinae formed the dominant component of all the Chironomidae recorded. This subfamily is associated with rivers in good to excellent conditions with minimal silt build up and high water quality. The subfamily Chironominae, while still present in three of the four Mammy Johnson’s sites appears to be substantially reduced in numbers and was not found as Site M1. This is a role reversal on the previous survey. The reduced presence of the Simulidae in the Mammy Johnsons River, in particular, is indicative of possible scouring by higher flows.
Some of the notably sensitive taxa that are were found in most sites and are associated with pristine or near pristine systems include: the dipteran subfamily Orthocladinae, the plecopteran Illiesoperla brevicauda (Grypopterygidae), the ephemeropteran family Leptophlebiidae, the trichopteran families Leptoceridae, Philopotamidae, Calamoceratidae, the molluscs, Hyriidae (freshwater mussels), the hydrobiid Posticobia brazieri (snail) and the freshwater shrimp Australatya striolata. There were larger numbers of the plecopteran family Grypopterygidae found at most sites, which is consistent with the previous survey. The dragonfly Austrogomphus (Gomphidae) characteristic of gravel bed streams with high water quality was found in both rivers.
There were also some noticeable absences or low numbers in the community composition, particularly in the upper reaches of the Mammy Johnsons River. These included many of the common larger, highly mobile and predominantly predatory insects such as the water beetles (Dystiscidae and Gyrinidae), dragonflies and damselflies (Odonata) and many of the common true bugs (Hemiptera) such as the Notonectidae and the larger Corixidae. A combination of an absence of pool macrophytes and the low light conditions produced by the closed canopy may have contributed to the absences. The damselfly, Ischnura heterosticta (Coenagrionidae) was only recorded at Site DDD2.
15 Shredder Ratio 0.8
0.7
0.6 M1 0.5 M2 0.4 M3 M4 0.3
Ratio Value Ratio M5 0.2 DDD2 0.1
0
02 03 03 04 04 05 05 06 06 07 07 - r- - r- - r- - r- - r- - ep a ep a ep a ep a ep a ep S M S M S M S M S M S
Figure 8. The observed variation in the Shredder ratio values for all sites since September, 2002.
The almost completely native species composition of the aquatic macroinvertebrate community of both river systems is largely attributed to the undisturbed nature of each river system, particular the Mammy Johnsons River and the heavily forested upper sections and dense riparian zone, which often forms a closed canopy, e.g. Site M3 (see Photos 5 and 6). A noticeable presence in the upper section of the Mammy Johnsons River and Site DDD2 was the low numbers of the introduced snail, Physa acuta. This appears to be a consistent occurrence from the previous survey where it was absent from all the river sites prior to 2007.
The majority of common insect taxa found at all sites are those that do not fly far or high as adults and require a natural riparian zone close to the river to complete their life cycles. The larvae also require good water quality and a constant supply of high quality allochthonous material to feed on. The insect taxa that are absent are the highly mobile (wide dispersers) predators that hunt by sight and are commonly found in more open water bodies such as Site DDD2. Therefore, the intact natural structure of the river and the riparian zone is contributing directly to the high biodiversity and overall community structure.
A notable feature of the current survey is the increase in the proportion and numbers of the shredder/grazer functional feeding group within the invertebrate community relative to the whole community. The major components of this feeding group include: the coleopteran family Elmidae, the Ephemeroptera, Plecoptera, Trichoptera and Gastropoda. The presence of this guild is significant, as they normally comprise a large proportion of healthy aquatic communities. The high consistent numbers, particularly of the trichopteran and ephemeropteran families Baetidae and Leptophlebiidae, indicate that most sites still have very healthy environmental conditions, although the previous low flow conditions do appear to have had an impact on the number of taxa present. The river sites recorded between 13 and 18 taxa within these groups whereas Site DDD2 recorded the lowest number with 7 taxa, which is to be expected with this non-flowing system. Another notable feature of both river systems is the high numbers of Plecoptera, represented by the species Illiesoperla brevicauda. This plecopteran was found in high numbers at most sites, except Site DDD2. Most of the EPT and shredder taxa register 8 - 10 on the SIGNAL index as they are highly sensitive to pollution.
16 This indicates that the Mammy Johnsons and Karuah Rivers are still both in very good condition.
Silt Tolerant Species Two graphs are presented to show the changes in silt tolerant taxa along the catchment and over time (see Figures 9-10). A large decrease in silt tolerant taxa was observed for all sites except Sites M5 and DDD2. Sites M5 on the Karuah River and DDD2 recorded numbers of taxa similar to the last survey. One possible explanation for the observed variation is the result of two large flood events which occurred in June and August. All sites, except Site DDD2, experienced significantly elevated water levels and high flow velocities that substantially scoured the substrate and removed much of the accumulated silt that had been deposited during the previous low flow periods.
Ratio of Silt tolerant taxa 0.3
0.25
0.2 M1 M2 0.15 M3 0.1 M4 M5 0.05 DDD2
0
3 3 4 4 5 5 6 6 7 7 -0 -0 -0 0 0 -0 0 p-02 r-0 p p r p- p p-0 ar-0 a e Se Ma Se M Se M Se Mar- Se Mar- S
Figure 9. The observed variation in the silt tolerant taxa ratio values since September, 2002
During periods of low flow, particularly during the extended dry period over the last three years, there has been a gradual build-up of silt in the streams. Reduced flow allows the settling out of fine particles and a reduction in scouring due to low water velocities. This in turn encourages silt tolerant taxa to increase in numbers. However, under normal flow conditions these coastal cobble systems typically have regular high-energy flows that remove most of the silt within the system. This leads to relatively low numbers of silt tolerant taxa in these communities under normal flows.
Figure 10 shows the distribution and diversity of silt tolerant taxa along the catchment for since September, 2002. The current pattern is similar to that observed in Surveys 7 and 8, where the number of silt tolerant taxa was low at Site M1, higher at Site M2, dropping at Site M3 and then decreasing downstream as flows increased down the catchment, thus reducing the amount of silt and its associated fauna. Surveys 7, 8 and 9 indicated that the region of the study area with the highest silt impacts over the last two years was between Sites M1 and M2, where the low flows has resulted in a pronounced increase in silt and silt tolerant taxa. The current survey recorded the highest value at Site M4 and the lowest value at Site M3. The high value, as discussed above, is attributed to the deposition of silt during the recent extended dry period. Whereas, Site M3 shows evidence scour via the impacts of elevated water levels.
17 Ratio of Silt tolerant taxa for each survey 0.3
03/09/2002 0.25 28/03/2003 25/09/2003 0.2 19/03/2004 03/06/2004 0.15 21/09/2004 10/03/2005 0.1 15/09/2005 07/04/2006 0.05 19/09/2006
Ratio of silt tolerant taxa tolerant silt of Ratio 07/03/2007 12/09/2007 0 M1 M2 M3 M4 M5 DDD2 Site
Figure 10. The observed variation in the silt tolerant taxa ratio values since September, 2002.
Site DDD2 This is the eighth survey of this artificial dam and has generally been precluded from the analysis and discussion of the other sites as they represent flowing water systems and constitute a very different aquatic ecosystem. The dam substrate has changed somewhat since the first survey. In the initial survey the substrate consisted mainly of a thick covering of dead or dieing vegetation made up mostly of grass, which had been submerged as the dam was filled. During the second survey all of the submerged terrestrial vegetation had died and decomposed resulting in a thick layer of organic detritus. With the current survey the organic detritus had been removed resulting in the substrate been composed of sand and gravel on the surface with thick clay/mud underneath. Macrophytes are establishing in the shallow water starting at approximately 2 metres from the shore out approximately 10 metres, adding to the number and complexity of habitats available within the ecosystem. The riparian zone now contains grasses and sedges growing down to the waters edge and starting to overhang the water. This riparian zone is providing good habitat for frogs and invertebrates. However, the presence of cattle has reduced the extent and cover of the grasses and sedges with many of the sedges showing signs of grazing.
As this ecosystem has only recently been formed it largely still contains the early colonising, wide ranging species. However, a new secondary community is becoming established and includes representatives of the EPT guide. The community is generally composed of predators such as the coleopteran families Dystiscidae and Hydrophilidae, the Odonata families Libellulidae (Nannophlebia) and Coenagrionidae (Ischnura), the large hemipteran families such as the Notonectidae and Corixidae and the chironomid midges particularly the subfamily Chironominae. All of these taxa are very tolerant of disturbance and poor water quality, although the water quality of this site is generally good. There are now also representatives of the EPT shredder guide including the mayflies (Caenidae) and caddis flies (Leptoceridae) and the filter feeder guild including the shrimp, Paratya australiensis and the bivalve Pisidium. The EPT taxa are present at this site due to the close proximity to the Mammy Johnsons River and a close riparian corridor allowing the dispersal of these taxa to this site. These taxa normally do not disperse far from a riverine environment. Although EPT taxa are generally
18 regarded as disturbance sensitive, the species observed at this site occur over a wide range of habitats, especially those that have the appropriate food sources and relatively good water quality.
Physico-Chemical Data
Survey 12 Units M1 M2 M3 M4 M5 DDD2 Temperature °C 13 13 13 13 13 17 Dissolved Oxygen mg/l Conductivity mS 170 200 200 200 130 350 pH ph units 7.5 7.5 7.4 7.4 7.5 7.5
Table 5. Physico-chemical data from each site sampled.
All physico-chemical parameters, except dissolved oxygen which was not measured, were again remarkably consistent along the length of the study area and all were well above the minimum requirements as set out by the ANZECC and ARMCANZ guidelines (2000). The range and variation of the physico-chemical parameters along the length of the river and over time for the Mammy Johnsons River as well as rainfall figures for the Mammy Johnsons River catchment can be seen in Figures 11-14.
Six monthly rainfall 2007
140.0 120.0 100.0 80.0 60.0
Raifall (mm) Raifall 40.0 20.0
0.0
7 7 7 7 7 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 /2 3 3 4 4 5 5 5 6 6 7 7 8 8 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 7 1 4 8 2 6 0 3 7 1 5 8 2 0 2 0 1 0 1 3 1 2 1 2 0 2 Time
Figure 11. The observed rainfall totals for the Mammy Johnsons River catchment, for the last six months from March to September, 2007.
Due to the failure of our standard water quality sampling equipment, as mentioned earlier, James Benson, Environmental Officer for Duralie Mine, conducted the collecting and recording of the above parameters. The results are presented in Table 5.
Rainfall (see Figure 11) over the last six months has been less intense and less frequent than the previous six months with only 226 mm falling up until early June. This was followed by 250 mm falling in June alone, followed by another major rainfall event in mid August. The total for the last six months was 612.4 compared with 325.6 mm in the previous spring period. Rainfall frequency and magnitude has been reduced since the second half of 2005. Over the last six months there have been eleven rainfall events over 10mm, five rainfall events over 20
19 mm and two events over 50 mm resulting in a lengthened period of low flow in the rivers. However, five of those events were after early June resulting in consistent flows over the last 3 months.
The observed temperatures for the current survey (see Figure 12) were similar to the previous September readings ranging from 13°C for all river sites (Sites M1 – M5) to 17°C for Site DDD2.
Water Temperature
35
30 M1 25 M2 20 M3 15 M4 M5 10 DDD2 Degrees Celsius Degrees 5
0
4 5 6 02 03 04 0 04 0 06 0 07 0 07# /20 /20 0 09/20 09/20 3/20 3/ 8/03/2 9/03 3/06/201/ 0/03/2005 7/04 9/09/207/0 0 2 25/09/20031 0 2 1 15/09/200 1 0 12/09/2 Sites
Figure 12. The observed variation in water temperature for all sites since September, 2002.
Conductivity (see Figure 13) was substantially lower than previous spring surveys and more comparable to the autumn surveys. It ranged from 130 µS/cm at Site M5 on the Karuah River to 200 µS/cm for all the Mammy Johnsons River sites except Site M1, which was 170 µS/cm. As with previous surveys, there is a slight trend of increasing conductivity downstream in the Mammy Johnsons River. pH (see Figure 14) was essentially neutral tending towards slightly alkaline but varied little across all sites ranging from 7.4 to 7.5. pH has remained very constant over time varying no more than 1 pH unit throughout the monitoring program.
Dissolved oxygen was not measured during the current survey. However, as the river was flowing above normal we assumed that the dissolved oxygen levels were well above minimum acceptable limits for all sites as they were satisfactory during most of the extended low flow periods observed in previous surveys. DO has not been graphed.
Site DDD2 The physico-chemical properties of the dam site are indicative of relatively good water quality. Water levels have not changed significantly as the dam has remained at the spill pipe level for an extended period allowing for the development of macrophytes and riparian vegetation. Generally, the water quality parameters of the dam have mirrored those of the rivers although values may be higher or lower. Temperature was higher compared with the other sites at 17°C, which is to be expected given the shallow edges and essentially no
20 riparian zone to cover the waters edge. Conductivity has decreased considerably from the previous four surveys but is comparable to the March 2005 survey (Survey 9). The observed reading is very low compared with regional groundwater levels and is considered fresh in the ANZECC and ARMCANZ guidelines (2000). pH was slightly alkaline and lower than most previous surveys. Therefore, the site has relatively high water quality.
Conductivity 800
700
600 M1
500 M2 M3 400 M4
300 M5 Microsemens 200 DDD2
100
0
02 03 03 04 04 04 05 05 06 06 07 7# 20 20 20 20 20 20 20 20 20 20 20 00 / / / / / / / / / / / /2 09 03 09 03 06 09 03 09 04 09 03 9 3/ 8/ 5/ 9/ 3/ 1/ 0/ 5/ 7/ 9/ 7/ /0 0 2 2 1 0 2 1 1 0 1 0 12 Site
Figure 13. The observed variation in conductivity values for all sites since September, 2002.
pH
9 8 7 M1 6 M2 5 M3 4 M4
pH Units pH M5 3 DDD2 2 1 0
2 3 3 5 6 6 7 # 0 00 00 004 0 00 0 00 /20 /2 /2 /2 /20 /2 09 3 3 09/20 4 09 3 3/ 8/0 9/0 / 7/0 / 7/0 09/2007 0 2 25/09/21 03/06/200421/09/200410/03/200515 0 19 0 / 12 Site
Figure 14. The observed variation in pH values for all sites since September, 2002.
21 Discussion The results of the current survey indicate that both the Mammy Johnsons and Karuah Rivers are still in good to very good condition and possess a highly complex and diverse aquatic ecosystem.
In summary the results show an overall increase in diversity values in all sites compared with those of the previous survey and comparable to those observed for the same period in 2006. The condition indices (SIGNAL, EPT Ratio and Shredder Ratio) mirrored each other and differed from the biodiversity values by showing a significant increases in condition values at all sites compared with the previous survey and were also comparable with the same period for the last four years. These results indicate that the riverine ecosystem values at Sites M1 - M5 are in fair to good condition, whereas, the high species diversity and number of EPT taxa indicate that the sites are in good to excellent condition. These results are almost identical to the previous autumn surveys from 2003 to 2006. This signifies that the community composition has remained very consistent in the number of pollution/disturbance sensitive taxa.
Over the last six months there has been a substantial increase in the volume and regularity of rainfall events (particularly over the last 3 months) producing higher regular flow levels in both rivers and maintaining higher water quality and providing a scouring impact on the substrate. The higher flow conditions have increased the scouring effects of the floods, which normally remove the accumulated fine sediments, algae and associated invertebrate fauna from the substrate. This then increases the amount of available habitat for the associated grazer and shredder fauna. The results have already registered an increase in overall ecosystem condition and an apparent increase in the proportion of EPT and grazer components in the community. However, as the number of species has remained relatively constant over the last two surveys, this apparent increase in ecosystem health is partially due to a reduction in the numbers of silt and disturbance tolerant taxa, which were removed by the scouring effects of the recent floods. There will, however, be a time lag of at least 6 to 12 months before substantial ecosystem benefits can be registered through an increase in biodiversity due to the time it takes for the lifecycles of the aquatic invertebrates to be completed. If conditions of flow and water quality remain favourable, the current season’s nymphs and larvae will be able to reproduced in numbers and replenish the community.
The seasonality of the normal lifecycle for most of the EPT taxa (as well as the majority of other aquatic insects) does impact on the apparent biodiversity of a river system. The lifecycles of aquatic invertebrates involves the development of the aquatic larvae over the winter months with mature larval emerging as adults from late spring to late summer resulting in an apparent increase in numbers of animals and species during this early spring period. This contrasts with the late summer period where many adults have left the water and larvae are young, small and highly cryptic (i.e. they live in the hyporheic zone / under the gravel substrate). This results in an apparent reduction in biodiversity and abundance and is reflected in the lower diversity of the EPT groups. However, the overall increase in diversity is caused by the lower flows producing a more stable environment, which then stimulates the numbers and diversity of silt/disturbance tolerant taxa.
The two main factors influencing the biological diversity and water chemistry are flow and landscape condition i.e. riparian zone condition. Flow is one of the main regulatory factors that determine biological activity and diversity within rivers, particularly in high-energy coastal systems. Aquatic communities are susceptible to change, in both numbers of organisms and community composition during periods of extreme flow conditions such as the rapid changes seen during high flows or the gradual change seen during low or no flows. Each extreme flow regime will produce flow conditions favourable to particular segments of the community and these components will then increase in numbers. The second major factor that has contributed to the high biodiversity and high water quality of both the Karuah and Mammy Johnsons River systems is the intact, native riparian vegetation found along the
22 banks of the rivers and the mature upland native forests. The lack of excessive sedimentation from erosion of the catchment and riverbanks has allowed a range of niches in the riverbed to be retained allowing the aquatic community to maintain a high diversity and efficiency in processing the nutrients and allochthonous matter that enters the system. This in turn produces higher water quality for all uses.
Overall, there has been a consistent number of taxa and a reduction in silt tolerant taxa and an apparent increase in EPT taxa resulting in a substantial increase in condition at all Mammy Johnson sites. Although there has been an overall increase in condition of the two river systems there was significant variability among the sites, often with contradicting results. There are four possible causes for this variability: i) differences in site geomorphology and river size; ii) variations in the habitat produced by the different flow regimes; iii) differences in the composition of the faunal communities associated with each particular type of river flow regime and iv) the seasonal life cycle differences of the different community components.
Therefore, the result of the current survey confirms what has previously been predicted and demonstrated, i.e. that the aquatic biodiversity is continuing to show the same or similar trends to that observed in previous years. The continued presence of high numbers of EPT taxa recorded at all sites (13 - 18 taxa) indicates that all sites are very healthy and showing no signs of environmental stress.
In conclusion, the results from the current survey suggest that the overall biodiversity and river environmental conditions are very good and that there are no apparent adverse effects on the aquatic macroinvertebrate fauna as a result of any activities arising from the operations of the Duralie Mine.
Acknowledgements We are grateful to Mr. John Trotter for his continued assistance in the field as well providing background information on water quality and site history.
References Anonymous. 1994. National River Processes and Management Program Monitoring River Health Initiative. River Bioassessment Manual Version 1.0. Department of the Environment, Sport and Territories, Canberra.
Besley, C.H., McEvoy, P.M. and Chessman, B.C. 1996. Biological Assessment of the Streams in the Stratford Coal Project Area. Australian Water Technologies, Ensight, Report Number 96/152.
Besley, C.H. and Growns, I. 1998. Biological Assessment of the Streams in the Stratford Coal Project Area. Australian Water Technologies, Ensight, Report Number 98/144.
Chessman, B.C. 1995. Rapid assessment of rivers using macroinvertebrates: a procedure based on habitat-specific sampling, family-level identification and a biotic index. Australian Journal of Ecology, 20(1):122-129.
Chessman, B.C., Growns, J.E. and Kotlash, A.R. 1997. Objective derivation of macroinvertebrate family sensitivity grade numbers for the SIGNAL biotic index: application to the Hunter River system, New South Wales. Marine and Freshwater Research, 48:159- 172.
23 Lenat, D.R. 1988. Water quality assessment of streams using a qualitative collection method for benthic macroinvertebrates. Journal of the North American Benthological Society 7(3):222-233.
Resh, V.H. and Jackson, J.K. 1993. Rapid assessment approaches to biomonitoring using benthic macroinvertebrates. In: Freshwater Biomonitoring and Benthic Macroinvertebrates. Eds Rosenburg, D.M. and Resh, V.H. Chapman & Hall, New York, 195-223.
Turak. E. and Waddell. N. 2000. New South Wales (NSW) Australian River Assessment System (AusRivas) Sampling and Processing Manual. NSW Environment Protection Authority, Monitoring River Health Initiative Technical Report Number 10. Environment Australia."
Williams, W.D. 1981. Australian Freshwater Life. The Invertebrates of Australian Inland Waters. Macmillan Education Australia Pty Ltd. Melbourne.
24 Appendix 1 A list of the macroinvertebrate species collected at the six sample sites on the Mammy Johnsons and the Karuah Rivers on the12th September 2007.
Order Family Species M1 M2 M3 M4 M5 DDD2 Acarina Eylaidae Eylais * Acarina Hygrobatidae undetermined * * * Bivalvia Hyriidae Alathyria * * * Bivalvia Sphaeridae Pisidium * * * * * Coleoptera Dystiscidae Antiporus * * Coleoptera Dystiscidae Barratthydrus * Coleoptera Dystiscidae Batrachomatus * * Coleoptera Dystiscidae Bidessus * * Coleoptera Dystiscidae Chostonectes * Coleoptera Dystiscidae Hyphydrus * Coleoptera Dystiscidae Necterosoma * * * Coleoptera Dystiscidae Sternopriscus * Coleoptera Elmidae Austrolimnius * * * * * Coleoptera Elmidae Kingolus * * Coleoptera Elmidae Notriolus * Coleoptera Gyrinidae Macrogyrus * * * * Coleoptera Haliplidae Haliplus * * * Coleoptera Hydrophilidae Berosus * * * * Coleoptera Hydrophilidae Helochares * Coleoptera Psephenidae Sclerocyphon maculatus * * Coleoptera Scirtidae Undetermined * * Decapoda Atyidae Australatya striolata * Decapoda Atyidae Paratya australiensis * * * * * * Diptera Ceratopogonidae Bezzia * * * * Diptera Chironomidae Chironominae * * * * Diptera Chironomidae Orthocladinae * * * * * Diptera Chironomidae Tanypodinae * * Diptera Culicidae Culicinae * Diptera Simulidae Simulium * * * * * Diptera Tabanidae Tabanus * Diptera Tanyderidae Tanyderus * * * Ephemeroptera Baetidae Bungona sp. 1 * * * Ephemeroptera Caenidae Caenid Genus C sp. * * * * * Ephemeroptera Caenidae Tasmanocoenis * * Ephemeroptera Leptophlebiidae Atalophlebia sp. AV12 * * * * Ephemeroptera Leptophlebiidae Austrophlebioides sp. AV9 * * * * * Ephemeroptera Leptophlebiidae Jappa * * * Ephemeroptera Leptophlebiidae Nousia * * * Ephemeroptera Leptophlebiidae Ulmerophlebia sp. AV1 * * * Gastropoda Ancylidae Ferrissia petterdi * * * Gastropoda Hydrobiidae Posticobia brazieri * * * * * Gastropoda Physidae Physa acuta * * Gastropoda Planorbidae Glyptophysa * Gastropoda Planorbidae Gyraulus * * * Hemiptera Corixidae Agraptocorixa * Hemiptera Corixidae Micronecta * * * * * Hemiptera Gerridae Limnogonus * Hemiptera Hydrometridae Hydrometra strigosa *
25 Hemiptera Naucoridae Naucoris Hemiptera Notonectidae Anisops * Hemiptera Notonectidae Enithares * * Hemiptera Pleidae Plea * * Hemiptera Veliidae Microvelia * Hirudinea Erpobdellidae Undetermined * Hirudinea Glossiphoniidae Undetermined * * * Isopoda Sphaeromatidae Cymodetta * * Megaloptera Corydalidae Archichauliodes guttiferus * * * * Odonata Coenagrionidae Ischnura heterosticta * Odonata Gomphidae Austrogomphus * * * Odonata Libellulidae Diplacodes * * Odonata Libellulidae Nannophlebia * * * Oligochaete Lumbriculidae Lumbricus variegatus * * * * * Oligochaete Tubificidae Undetermined * * * Platyhelminthes Dugesiidae Undetermined * Plecoptera Grypopterygidae Illiesoperla brevicauda * * * * * Trichoptera Calamoceratidae Anisocentropus * * * Trichoptera Conoesucidae Coenoria sp. AV1 * * * Trichoptera Ecnomidae Ecnomus * * Trichoptera Helicopsychidae Helicopsyche * Trichoptera Hydrobiosidae Taschorema * * Trichoptera Hydropsychidae Asmicridea sp.AV1 * * Trichoptera Hydropsychidae Cheumatopsyche sp.AV1 * * * * Trichoptera Hydroptilidae Hydroptila scamandra * * Trichoptera Leptoceridae Oecetis * * * * Trichoptera Leptoceridae Triplectides volda * Trichoptera Philopotamidae Chimarra * * * * * 52 76 M1 M2 M3 M4 M5 DDD2 No of Families 31 32 23 26 29 23 No of Genera 38 37 29 32 34 29 SIGNAL - HU97B 5.9 6.1 6.0 6.7 6.2 5.1 EPT 11 13 11 10 13 4 EPT ratio 0.29 0.41 0.48 0.38 0.45 0.17 Shredder Ratio 0.45 0.49 0.45 0.5 0.53 0.24 Silt Tolerant Taxa 4 5 3 6 5 5 Silt Tolerant Taxa Ratio 0.11 0.14 0.1 0.19 0.15 0.17
26 Duralie Coal Project - Biological Monitoring of the Streams Adjacent to the Duralie Coal Mine Study 1, Survey 13, Feb 2008.
INVERTEBRATE IDENTIFICATION AUSTRALASIA 51 Panorama Parade, Panania, NSW 2213, Phone (02) 6771 1458 Mobile 0412 372 388 Email: [email protected] or [email protected] Table of Contents
Executive Summary ...... 3
Introduction...... 4
Study Area and Sampling Sites...... 4
General Description...... 4
Mammy Johnsons River ...... 6
Karuah River...... 6
Diversion Drain Dam No.2...... 6
February Site Images...... 6
Methodology...... 8
Macroinvertebrate Sampling...... 8
Identification ...... 9
Data analysis ...... 9
Silt Tolerant Species...... 10
Physico-Chemical Data ...... 11
Results ...... 11
Macroinvertebrate Data ...... 11
Silt Tolerant Species...... 17
Site DDD2...... 18
Physico-Chemical Data ...... 19
Site DDD2...... 22
Discussion...... 22
Acknowledgements ...... 24
References...... 24
Appendix 1...... 26
2 Executive Summary Duralie Coal Pty Ltd commenced the establishment of an open cut coalmine in 2002, adjacent to the Mammy Johnsons River, upstream from the township of Stroud Road. As part of Duralie Coal’s environmental monitoring program, Invertebrate Identification Australasia was commissioned to conduct biological monitoring of the streams near the mine including portions of the Mammy Johnsons and Karuah Rivers. This report is the thirteenth environmental assessment of the aquatic ecosystems associated with the Duralie Mine and is the twelfth since the mine became operational.
Six sites were sampled on the 29th February 2008 for aquatic macroinvertebrates and water quality using rapid assessment techniques. A total of 61 species representing 60 genera were recorded in 44 families. In addition, five biological indices were used to determine the condition of the streams in and adjacent to the Project area.
The results of the current survey indicate that there has been a substantial improvement in ecosystem condition compared with those recorded in previous years and show no evidence of any adverse effects on the aquatic macroinvertebrate community and, therefore, the river ecosystem, as a result of the mine’s operations. In addition, 17 significant rainfall events have occurred over the last six months. This regular high rainfall and resultant river flows have resulted in a change in the community composition from a low flow dependent community to one that prefers high flow conditions. This has lead to an increase in the environmental indices compared with the September 2007 survey, and some of the highest, if not the highest recorded so far. This data indicates that all sites have very healthy macroinvertebrate communities due to higher water quantity and quality conditions.
The environmental monitoring of the water quality and the aquatic ecosystem within the Diversion Drain Dam (DDD2) above the mine water storage dam (west of the mining operation) is continuing. This monitoring program has been established to monitor any impacts of potential saline run-off from the irrigation of saline mine water onto the ridges and slopes surrounding the mining area upon the water quality and/or the local macroinvertebrate community. Results from the ninth survey of the dam indicate that the electrical conductivity is still very low, and there is a diverse aquatic community established and continuing to develop consisting increasingly of disturbance sensitive taxa. Macrophytes are well established, which will add to the diversity of habitats present in the dam and will, over time, assist with an increase in diversity and community complexity.
3 Introduction Duralie Coal Pty Ltd commenced an open cut coalmine operation in 2002, adjacent to the Mammy Johnsons River, upstream of the township of Stroud Road. As part of Duralie Coal’s environmental monitoring program, Invertebrate Identification Australasia was commissioned to conduct biological monitoring of the streams near the mine. This report provides the thirteenth environmental assessment of the aquatic ecosystems of Mammy Johnsons River and the Karuah River above the junction with Mammy Johnsons River. It also reports on the ninth water quality and aquatic ecosystem survey of the Mine’s Water Diversion Drain Dam No. 2 (DDD2).
Aquatic macroinvertebrate communities have been used as a reliable and cost effective environmental indicator of stream condition for more than 20 years across Australia. These communities have long been recognised as being ideally suited for the assessment of river health and condition as they are diverse, occupy every niche within a water body including the riverbed, water column and surface, are one of the major contributors to the processing of energy through a river system and responds directly to physico-chemical changes within the aquatic environment. The composition of this community consists of a range of predators, grazers, shredders and filter feeders and reliably reflects both natural and threatening processes operating within a catchment. The ubiquitous distribution and specific habitat requirements of each component at both the species and community levels, enables the use of their diversity as an indicator of ecological disturbance within a catchment.
The environmental monitoring of the water quality and aquatic ecosystem within one of the Mine’s water dam diversion drain dam located to the west of the mining operation continues. This monitoring program has been established to monitor for any changes to the diversion drain dam water quality and/or the local macroinvertebrate community as a result of potential saline run-off from irrigation onto the ridges and slopes surrounding the mining area.
Study Area and Sampling Sites General Description The Duralie Coal Mine is situated approximately 10 km northeast of the township of Stroud Road on the western side of Mammy Johnsons River on the New South Wales central coast. The Mammy Johnsons River and the Karuah River are the two major tributaries of the Karuah River system. The Mammy Johnsons River and the Karuah River below the junction with Mammy Johnsons are the only major watercourses that would potentially be affected by operations from the Duralie mine.
Site code Site name and description Grid Reference M1 Above mine area, near gauging station. 400607N, 6430921E M2 Downstream of M1 and above the mine area 401262N, 6427007E M3 Downstream of M2 and below mine area 401463N, 5425640E Downstream of M3 and below mine area. 30m west of M4 400388N, 6422495E Johnsons Ck Rd M5 Karuah River at Stroud Road on Stroud Rd/Dungog Road 401462N, 6425639E DDD2 Diversion Drain Dam 2 above Mine Water Storage Dam 387750N, 6424400E
Table 1. Sampling sites.
The region had been experiencing a continuation of below average rainfall prior to June, 2007, which had prevailed in the region for the previous four-five years. This decrease in rainfall has provided base (low) river level conditions interspersed with some minor ‘flushes’
4 Figure 1. Map showing the location of the five monitoring Sites M1 - M5 and their position relative to the Duralie and Stratford mine sites. or flood events. In the six months prior to this survey (September, 2007 to February, 2008) there has been a significant increase in the frequency and volume of the rainfall and, therefore, river flow events. This has resulted in regular high flows over the last six months.
5 Just prior to the survey there was another large rainfall event that led to elevated river levels at the time of sampling. The higher water levels at all sites, resulted in the river being turbid, most pools having current and some areas of riffles being inaccessible (Karuah River, Site M5) due to strong currents.
Five sites were selected (Figure 1, Table 1) from amongst the sites initially included in the then proposed mine’s Environmental Impact Study (prepared by Woodward Clyde). These sites were sampled on the 29th February 2008 for aquatic macroinvertebrates and water quality using rapid assessment techniques. Four sites are located along the Mammy Johnsons River, with two are located above the mine (Sites M1 and M2) and two below the mining area (Sites M3 and M4). One site is located on the Karuah River (Site M5) at Stroud Road, upstream of the junction with Mammy Johnsons River. Site M3 has been relocated approximately 50m downstream from the original site in order to incorporate a larger, stony riffle section, a habitat that was previously absent from Site M3.
Mammy Johnsons River The Mammy Johnsons River is a small meandering coastal stream that passes through predominantly heavily wooded native forest with a smaller amount of cleared, grazing country found mainly in the lower sections. For a more complete description of each of the study sites refer to previous reports (Reports 1-11). During this survey the pools and riffles were quite turbid due to the floods and no green filamentous algae was observed at any site. There was no apparent deposition of silt as this had been extensively scoured by a number of recent flood events.
Karuah River The Karuah River joins the Mammy Johnsons River below Stroud Road and possesses similar river geomorphological characteristics and substrate composition as that of Mammy Johnsons River. The Karuah River, however, is a larger river of approximately double the water volume of the Mammy Johnsons and therefore, has higher velocities and much larger (coarser) substrate size in the riffle zones. The water appeared turbid as in the Mammy Johnsons River. No green filamentous algae was observed in the Karuah River during this survey; and the cobbles and boulders in the riffles had been obviously scoured clean of any algae, silt or detritus.
Diversion Drain Dam No.2 A sixth site was a diversion drain dam above the mine water storage dam (west of the mining operation) in order to be able to assess whether saline water runoff was occurring from the irrigation of mine water onto the ridges and slopes to the west of the mining operation. The Diversion Drain Dam No. 2 (Site DDD2) is one of four dams established several years ago to collect rainfall runoff from the slopes and hillsides surrounding the mine as well as mine irrigated water (which has moderate levels of salinity) in order to control the rate at which runoff enters the drain. The development of the foreshore riparian zone and macrophyte beds are continuing with the natural colonisation of the near shore zone by sedges and floating macrophytes. There had been no recent irrigation of the hillsides (pers com. John Trotter) due to the high rainfall levels and this has resulted in very low conductivity levels within the dam.
February Site Images The following twelve photographs (Photos 1 - 12) of Sites M1 - M5 and DDD2 were taken during the current survey and illustrate the prevailing conditions of the two rivers and dam as well as the extent of the riparian zone observed at each site. Photos 13-14 are of Site DDD2 taken during the previous September 2007 survey (Survey 12) to show the different states of development of the macrophyte community within this site. Note that the water levels are as high or higher in the river than the previous survey but consistent in the dam with the previous survey.
6 1 2
Site M1, viewed downstream (1); viewed upstream (2) (February, 2008).
3 4
Site M2, viewed downstream (3); viewed upstream (4) (Taken February, 2008).
5 6
Site M3, viewed downstream (5); viewed upstream (6) (Taken February, 2008).
7 8
Site M4, viewed downstream (7); viewed upstream (8) (Taken February).
7 9 10
Site M5, viewed downstream (9); viewed upstream (10) (Taken February, 2008).
11 12
Site DDD2, east bank in foreground (11); north bank in foreground (12) (Taken February, 2008).
13 14
Site DDD2, east bank in foreground (13); north bank in foreground (14) (Taken September, 2007).
Methodology Macroinvertebrate Sampling Each site was sampled using two standardised methods outlined in the River Bioassessment Manual (Anon. 1994) and the NSW AUSRIVAS Sampling and Processing Manual (2000). The results are presented in Table 4.
The first method involves the rapid assessment techniques employed in NSW AUSRIVAS Sampling and Processing Manual (2000). In this survey two habitats were sampled, 1) pool edge and 2) riffles.
1a) Pool edges are sampled with a macroinvertebrate kick net that is drawn through the water over the substrate starting from 1.5m off the edge and working in towards the
8 bank along the edge in a rapid motion for approximately 10m. In order to sample a larger area of a river reach, smaller samples of approximately 1-2m are taken along the length of the pool to a maximum combined length of 10 metres.
1b) Riffles are sampled with a kick net held in the riffle with the net extending downstream while the substrate directly upstream is agitated with either hands or feet. The sampling strategy is the same as for edges, where, in order to sample a larger area of the riffle zone, small samples of approximately 1-2m are taken along the length of the riffle to a maximum combined length of 10 metres. Care needs to be taken to turn over boulders and to clean boulders and cobbles with the hands to remove encrusting animals. The samples from each habitat are combined in the results to give a comprehensive species list for the whole site.
2) The second method involves targeted opportunistic sampling of macroinvertebrates from a variety of habitats and substrates, when available. Habitats sampled may include: • logs and wood from within pools, pool edges and riffles; • large rocks and boulders from within pools and riffles; • kick net sweeps through macrophyte beds and • kick net sweeps under bank overhangs.
All samples are preserved in the field with 100% ethanol and returned to the laboratory for sorting and identification.
Identification All samples were sorted under a stereomicroscope and stored in 70% alcohol. Specimens were identified to genus where possible, (except for Chironomidae, Oligochaeta and Platyhelminthes which are identified to family/subfamily), using a combination of current taxonomic works and keys and comparison with voucher specimens in the reference collections of Invertebrate Identification. Identification references included Williams (1981) and the taxonomic identification series produced by the Murray Darling Freshwater Research Centre.
Data analysis When viewing the results of this or any other ecological study it should be kept in mind that the study of organisms and ecology is not an exact science and that there are small degrees of variability with the data and therefore the analysis’s and that the results should be considered as guidelines or indicators to the changes occurring in the environment and not as numbers set in concrete. There are many factors that cause the variability of community data such as collecting techniques, the experience of the collector, climatic conditions that change the microhabitats and therefore the distributions of organisms. We endeavor to reduce the amount of variability, by having the same person conduct the survey each time, by surveying/collecting in a consistent way each survey, and by surveying as many habitats as possible to collect as wide a range of organisms as possible.
SIGNAL HU97B (Chessman et al., 1997). SIGNAL is an acronym for ‘Stream Invertebrate Grade Number - Average Level’, and is a biotic index of pollution tolerance or sensitivity (see Table 2). Each invertebrate family is awarded a pollution sensitivity rating from 1 to 10, with 10 being the most sensitive species, i.e. species only found in pristine/high water quality locations. These values are summed for all families present that have been allocated a SIGNAL value and divided by the number of families to provide an average grade for the stream. The SIGNAL values are between 1 and 10 with values equal to or greater than 6 representing clean water (good); 5.0-5.9 doubtful quality (fair), possibly mild pollution (poor) 4.9 – 4.0 and less than 4, probable severe pollution (very poor).
9 The SIGNAL HU97B is an updated version of the original SIGNAL 95 Chessman (1995) index and has been used from the beginning of the Duralie surveys for consistency. The original SIGNAL index was developed in the lower Blue Mountains whereas the 97 version was developed for the Hunter Valley and therefore is a more appropriate measure of stream environmental condition for this area.
SIGNAL -HU97B Probable water quality status
>7 Excellent 6-7 Good 5-6 Fair 4-5 Poor <4 Very poor
Table 2. Interpretation of water quality status using SIGNAL -HU97B scores (Chessman et al., 1997).
EPT Richness. The second index is based on three groups of insects that contain a majority of pollution sensitive taxa (Lenat, 1988). All species of Ephemeroptera, Plecoptera and Trichoptera are identified and then the number of distinct taxa counted (see Table 3). The EPT measure is based on the observation that the majority of taxa in these groups are particularly pollution sensitive. This feeding guild is important to the ‘health’ of an aquatic ecosystem because they break down the allochthonous material (leaves and twigs) that falls in or is washed into streams. Coarse allochthonous matter is the primary energy source for most aquatic ecosystems. By breaking down this material, energy is transferred from one feeding group to another thereby increasing the food resources for other feeding groups and in turn increasing biodiversity. An absence or low number of these groups, through increases in pollution and/or disturbance, results in decreased energy processing and biodiversity.
EPT genus richness Probable condition of macroinvertebrate community
>6 Healthy 5-6 Slightly impaired 3-4 Moderately impaired 1-2 Severely impaired 0 Grossly impaired
Table 3. Interpretation of the EPT genus richness scores (Besley et al., 1998).
Number of Families. All macroinvertebrate families are separated and counted. The number of families present generally decreases with decreasing water quality and is used as a comparative measure of community change over time.
Functional Feeding Groups. Ratio of shredder taxa to total number of taxa. As with Numbers of Families the higher the ratio of shredders the better the water quality and is used as a comparative measure of community change over time.
Silt Tolerant Species The Environmental Management Plan of the Duralie Mine states that the aquatic fauna assemblages need to be assessed for silt tolerant fauna, as the presence of such fauna can
10 provide an indication of the degree of heavy sediment pollution. The main indicator families are the Dugesiidae, Lymnaeidae, Ancylidae, Planorbidae, Psephenidae, Chironomidae, Caenidae, Pyralidae and Ecnomidae.
The silt tolerant taxa values are best examined against the total number of taxa sampled from each site i.e. the silt tolerant ratio, as the variation of values is significantly reduced compared with examining the number of taxa alone. This index is used as a comparative measure of community changes over time.
Physico-Chemical Data Physical and chemical parameters were measured at each site in situ and included temperature, dissolved oxygen, conductivity and pH. The results are presented in Table 5.
Results Macroinvertebrate Data A total of 60 genera in 44 families were recorded during the current survey. Sites M1 and M4 recorded the highest diversity with 31 and 28 genera, respectively, on the Mammy Johnsons River, while the Karuah River (Site M5) recorded 29 genera. The values are significantly lower across all sites except for Site DDD2 where they are only slightly lower but comparable with previous surveys. Site M2 recorded the lowest diversity of the river sites with 22 genera. This is considerably lower than all previous surveys except for the initial 2002 survey. Site DDD2 had the third highest recorded diversity value for this site with 28 genera, which is comparable with the September, 2007 survey and included 12 taxa not found at the other sites sampled (an increase of 3 taxa since last year’s survey).
Survey 13 - 29/02/2008 M1 M2 M3 M4 M5 DDD2 SIGNAL - HU97B 5.8 6.8 6.4 6.4 6.7 5.0 No of Families 25 18 20 20 24 23 No of Genera 31 22 26 28 29 28 EPT 12 12 11 12 14 6 EPT ratio 0.39 0.55 0.42 0.43 0.48 0.21 Shredder Ratio 0.58 0.68 0.62 0.64 0.66 0.32 Silt Tolerant Taxa 7 2 2 4 4 5 Silt Tolerant Taxa Ratio 0.23 0.09 0.08 0.14 0.14 0.18
Table 4. Summary Table of numbers of genera, families and indices. A full list of the taxa found is presented in Appendix 1.
The variation in the number of genera observed at each site since September, 2002 is illustrated in Figures 2-3. The graph of biodiversity values (= number of observed genera) recorded for the current survey shows an overall decrease for all sites compared with the March, 2007 survey. The normal pattern of diversity recorded along the river commences with Site M1 having a high diversity followed by a drop down to Sites M2 and M3 followed by a steady increase downstream to Sites M4 and M5. In this survey the pattern of variation along the river (Figure 3) shows a lowering in diversity downstream towards Site M2 on the Mammy Johnsons River, followed by a gradual increase downstream to Site M5. These values have remained relatively consistent since Survey 3 in 2003.
The condition index (SIGNAL) values differed from the biodiversity values by showing an increase or stable condition in values at all sites as opposed to a decrease in biodiversity values. Figure 4 illustrates a gradual increase in condition of the river by the graphed trend lines for Sites M3 and M4. The SIGNAL values for this survey ranged from 5.8 to 6.8 for the river sites, (Sites M1 and M2), respectively. The SIGNAL value for M2 of 6.8 is the
11 Aquatic Biodiversity
50 45 M1 40 M2 35 M3 30 M4 25 M5 20 DDD2 15 No. of Genera 10 5 0
02 03 -04 04 -05 05 06 07 ep- ar-03 ep- ar ep- ar ep- ar- ar- S M S M S M S M Sep-06M Sep-07
Figure 2. The observed variation in the number of genera recorded for all sites since September, 2002.
Aquatic Biodiversity 03/09/2002 28/03/2003
50 25/09/2003
45 19/03/2004
40 03/06/2004
35 21/09/2004 30 10/03/2005 25 15/09/2005 20 07/04/2006
No. ofGenera 15 19/09/2006 10 07/03/2007 5 12/09/2007 0 29/02/2008 M1 M2 M3 M4 M5 DDD2
Figure 3. The observed variation in the number of genera recorded for all sites since September, 2002.
highest SIGNAL value recorded from all surveys. Sites M3 and M4 had similar values of 6.4, while Site M5 recorded the second highest value of 6.7. Site M1 recorded the lowest value again for the river sites with a value of 5.8. The lowest overall value recorded was 5.0 for Site DDD2, which is the second highest value recorded for this site since sampling began. A significant feature of these results is the consistently high values recorded along the surveyed length of the Mammy Johnsons River and its comparative similarity to the Karuah River site.
12 These values indicate that Sites M1 to M5 are in fair to good condition. Even though the SIGNAL values appear to suggest a lower condition rating compared with the other indices, the high species diversity and relative number of EPT taxa compared with the silt tolerant taxa indicate that the sites are in good to excellent condition.
The variation in SIGNAL values along the river and the diversion drain since September, 2002 is illustrated in Figures 4-5. Each survey, so far, has shown the same pattern with little overall variation along the river and a similar pattern over time at all sites. The current survey’s results are the highest recorded values for Sites M2 and M3 and equal highest for Site M5 and second highest for Site DDD5. This signifies that the community composition has remained very stable over time in the number of pollution/disturbance sensitive taxa, particularly within the EPT group, even with the impact of the prolonged years of drought leading to prolonged periods of low flow. The variations of SIGNAL values and lower silt tolerant taxa values along the Mammy Johnsons River catchment reflects the slightly different geomorphology and flow rates i.e. higher flow and courser substrates, while the Karuah River had more favourable conditions for the EPT group of organisms. Even though the number of taxa is generally less compared with the Mammy Johnson’s sites the condition index values of the taxa present (higher numbers of high value EPT taxa and lower numbers of lower value silt tolerant taxa) results in higher scores. The overall results of the current survey show an increase in river condition compared with the September, 2007 survey (Survey 12). The SIGNAL index is also calculated for the dam site (Site DDD2), although it is not really appropriate for this particular site (a standing water system) as it was originally developed for flowing river systems. Nonetheless, it is still useful in mapping the changes in the community structure of the dam over time. The results indicate a very comparable level in condition compared to those observed in Survey 12 and appears to have stabilised. However, it is still an improvement on all of the previous September surveys.
SIGNAL 97
8 M1 7 M2 6 M3 5 M4 4 M5 3 DDD2 2 SIGNAL ValueSIGNAL Linear (M4) 1 0 Linear (M3)
5 7 -03 -03 04 -05 0 06 0 ep ep- ep- Sep-02Mar S Mar- Sep-04Mar S Mar- Sep-06Mar-07S
Figure 4. The observed variation in the SIGNAL-97 values for all sites since September, 2002.
The EPT index values (see Figure 6) demonstrate a significant increase in numbers of EPT taxa across all sites compared to the same period last year. This trend is different from previous annual patterns in that instead of showing a decrease in numbers from the previous spring surveys there was a continuous increase in taxa. This pattern is similar to the March, 2004 – March, 2005 surveys. These results suggest that the pronounced increase in values has occurred as a result of aseasonal climatic trends.
13 03/09/2002 SIGNAL 97 28/03/2003
8 25/09/2003 7 19/03/2004 6 03/06/2004 5 21/09/2004 4 10/03/2005 15/09/2005 3 07/04/2006
SIGNAL Value SIGNAL 2 19/09/2006 1 07/03/2007 0 12/09/2007 M1 M2 M3 M4 M5 DDD2 29/02/2008
Figure 5. The observed variation in the SIGNAL-97 values for all sites since September, 2002.
No. of EPT taxa
20 18 16 M1 14 M2 12 M3 10 M4 8 M5 6 DDD2 4
No. of taxa at each site each at No. taxa of 2 0
3 4 5 7 0 -03 -0 -04 -0 0 p-02 p p p-06 p-07 e e e S Mar- Se Mar Se Mar Sep-05 Mar-06S Mar- S
Figure 6. The observed variation in the EPT values for all sites since September, 2002.
The EPT values are best examined against the total number of taxa sampled i.e. the EPT ratio, as the variation of values is usually significantly reduced. Figure 7 illustrates the EPT ratio for all the sites across the thirteen surveys to date. The ratio also recorded a second significant increase in values for all sites compared with the two previous surveys ranging from 0.39 for Site M1 to 0.55 for Site M2. Therefore, Site M2 had the highest proportion of EPT taxa while Site M1 had the lowest. The EPT ratio values previously clearly separated the three major
14 habitats i.e. the Karuah River (Site M5 – the higher flow system) recording a relative high value, the Mammy Johnsons River (the lower flow and finer sediments and courser substrate system) sites have very similar values and Site DDD2 (the non-flowing system) recorded the lowest value. However, the recent high flow events have blurred the boundaries between Site M5 and the rest of the Mammy Johnsons River sites with Sites M3 and M2 overlapping Site M5. The significant increasing in number of EPT taxa within the Mammy Johnsons River has made the distinction between the rivers no longer clear cut. The differences between the two river systems are most noticeable during periods of low flow when average flow velocities are higher in the Karuah River with larger substrate types.
EPT Ratio
0.6
0.5 M1 M2 0.4 M3 0.3 M4 M5 0.2 DDD2 EPT Ratio Value 0.1
0
2 3 4 4 5 6 7 0 03 0 06 0 - r-0 - -0 r-07 ep-0 ar Sep- Mar S Ma Sep- Mar-05 Sep-0 M Sep Ma Sep-
Figure 7. The observed variation in the EPT ratio values for all sites since September, 2002.
The shredder ratio values are illustrated in Figure 8 and are similar to the EPT index with a significant increase in values at all sites, where all sites have recorded their highest values yet. All sites, except Site M5, were higher than the previous survey and ranged from 0.58 at Site M1 and 0.68 at Site M2 to 0.66 at Site M5.
The most significant change in the community found during this survey was the apparent increase in the number of grazer species (including the EPT group of taxa) compared with the significant lowering of silt tolerant taxa (see below). The common and consistently recorded taxa belong to the following groups: the freshwater shrimp Paratya australiensis, the coleopteran family Elmidae (beetles); the dipteran family Orthocladinae (midges); the ephemeropteran families Leptophlebiidae and Baetidae (mayflies), the plecopteran family Grypopterygidae (stone flies), the trichopteran families Hydropsychidae, Philopotamidae (caddis flies) and the molluscan families Sphaeridae (Pisidium) and Hydrobiidae (Posticobia brazieri).
The considerable reduction in the presence of dipterans at all sites including the subfamilies of the Chironomidae (particularly the Orthocladinae) are indicative of a major change to the environment leading to a decrease in numbers. The chironomid subfamily Orthocladinae formed the dominant component of all the Chironomidae recorded. This subfamily is associated with rivers in good to excellent condition with minimal silt build up and high water quality. The subfamily Chironominae, while still present in three of the four Mammy Johnson’s sites, appears to be substantially reduced in numbers and was not found as Sites M2
15 and M5. This is a role reversal on the previous autumn surveys. The absence of the Simulidae in the Mammy Johnsons River, in particular, is indicative of possible scouring by higher flows.
Shredder Ratio
0.8 0.7 0.6 M1 M2 0.5 M3 0.4 M4 0.3 M5
Ratio Value 0.2 DDD2 0.1 0
3 4 5 6 7 02 0 03 0 04 0 05 0 06 0 07 - r- - r- - r- - r- - r- - ep a ep a ep a ep a ep a ep S M S M S M S M S M S
Figure 8. The observed variation in the Shredder ratio values for all sites since September, 2002.
Some of the notably sensitive taxa that are were found in most sites and are associated with pristine or near pristine systems include: the dipteran subfamily Orthocladinae, the plecopteran Illiesoperla brevicauda (Grypopterygidae), the ephemeropteran family Leptophlebiidae, the trichopteran families Leptoceridae, Philopotamidae, Calamoceratidae, the hydrobiid Posticobia brazieri (snail) and the freshwater shrimp Australatya striolata. There were larger numbers of the plecopteran family Grypopterygidae found at most sites, which is consistent with the previous survey. The dragonfly Hemigomphus (Gomphidae) is characteristic of gravel and sandy bed streams with high water quality, was found only at SiteM2 in Mammy Johnsons River. A notable discovery from the Karuah River site (Site M5) was the first record of a relatively rare mayfly from the Family Ameletopsidae (Mirawara sp). These are very large mayfly nymphs that can get up to 30 mm long. They occur in stony streams with high water quality and apparently burrow into the cobble substrate during the day and emerge at the surface at night to feed (Campbell, 1980) thus the most likely reason why they have not been collected before. Although no SIGNAL rating is available for them they occur in streams with high water quality and are a good indicator of high stream condition.
There were also some noticeable absences or low numbers in the community composition, particularly in the upper reaches of the Mammy Johnsons River. These included many of the common larger, highly mobile and predominantly predatory insects such as the water beetles (Dystiscidae), dragonflies and damselflies (Odonata) and many of the common true bugs (Hemiptera) such as the Notonectidae and the larger Corixidae. A combination of an absence of pool macrophytes and the low light conditions produced by the closed canopy as well as the high flow levels may have contributed to the absences. These groups are visual predators that prefer still open water bodies as habitat. Of the four genera of dragonflies and damselflies recorded, three were found only at Site DDD2, while Hemigomphus was recorded from Site M2.
16 The almost completely native species composition of the aquatic macroinvertebrate community of both river systems is largely attributed to the undisturbed nature of each river system, particular the Mammy Johnsons River and the heavily forested upper sections and dense riparian zone, which often forms a closed canopy, e.g. Site M3 (see Photos 5 and 6). A noticeable absence at all sites was the introduced snail, Physa acuta. This appears to be a consistent trend from the previous survey where it was absent from all the river sites prior to 2007.
The majority of common insect taxa found at all sites are those that do not fly far or high as adults and require a natural riparian zone close to the river to complete their life cycles. The larvae also require good water quality and a constant supply of high quality allochthonous material to feed on. The insect taxa that are absent are the highly mobile (wide dispersers) predators that hunt by sight and are commonly found in more open water bodies such as Site DDD2. Therefore, the intact natural structure of the river and the riparian zone is contributing directly to the high biodiversity and overall community structure.
A notable feature of the current survey is the increase in the proportion and numbers of the shredder/grazer functional feeding group within the invertebrate community relative to the whole community. The major components of this feeding group include: the coleopteran family Elmidae, the Ephemeroptera, Plecoptera, Trichoptera and Gastropoda. The presence of this guild is significant, as they normally comprise a large proportion of healthy aquatic communities. The high consistent ratio of EPT and Shredder taxa, particularly the trichopteran and ephemeropteran families Baetidae and Leptophlebiidae, indicate that most sites have very healthy environmental conditions, although the previous low flow conditions do appear to have had an impact on the number of taxa present. The river sites recorded between 15 and 19 taxa within these groups whereas Site DDD2 recorded the lowest number with 9 taxa, which is to be expected with this non-flowing system. Another notable feature of both river systems is the high numbers of Plecoptera, represented by the species Illiesoperla brevicauda. This plecopteran was found in high numbers at most sites, except Site DDD2. Most of the EPT and shredder taxa register 8 - 10 on the SIGNAL index, as they are highly sensitive to pollution. This indicates that the Mammy Johnsons and Karuah Rivers are both in very good condition.
Silt Tolerant Species Two graphs are presented below to show the changes in silt tolerant taxa along the catchment and over time (see Figures 9-10). A large decrease in silt tolerant taxa was observed for all sites except Sites M5 and DDD2. Site M1 recorded the highest number (7) of taxa followed by 5 at Site DDD2, where as Sites M2 and M3 both recorded the lowest number of 2 taxa. All sites, except Site DDD2, experienced significantly elevated water levels and high flow velocities that substantially scoured the substrate and removed much of the accumulated silt that had been deposited during the previous low flow periods. The sites that have the least numbers probably have the highest scouring effect.
During periods of low flow, particularly during the extended dry period over the previous four years, there has been a gradual build-up of silt in the streams. Reduced flow allows the settling out of fine particles and a reduction in scouring due to low water velocities. This in turn encourages silt tolerant taxa to increase in numbers. However, under normal flow conditions these coastal cobble systems typically have regular high-energy flows that remove most of the silt within the system. This leads to relatively low numbers of silt tolerant taxa in these communities under normal flows.
Figure 10 shows the distribution and diversity of silt tolerant taxa along the catchment for since September 2002. The current pattern is similar to that observed in Survey 1 in September 2002, where the number of silt tolerant taxa was high at Site M1, lower at Site M2, and gradually increasing in numbers downstream. All sites shows evidence of scour via the
17 impacts of elevated water levels, however, during this survey the scouring was most prevalent at Sites M2 and M3, while Site M1 had the least impacted area.
Ratio of Silt tolerant taxa
0.3
0.25 M1 0.2 M2 M3 0.15 M4 0.1 M5 DDD2 0.05
0
3 3 4 7 0 -06 r-0 p- r-0 p-04 r-05 p-0 a a e a ep e Sep-02M Se M S M Sep-05Mar-06S Mar-07S
Figure 9. The observed variation in the silt tolerant taxa ratio values since September, 2002
Ratio of Silt tolerant taxa for each survey
0.3 03/09/2002 28/03/2003 0.25 25/09/2003 19/03/2004 0.2 03/06/2004 21/09/2004 0.15 10/03/2005 15/09/2005 0.1 07/04/2006 19/09/2006 0.05 07/03/2007 12/09/2007 Ratio of silt tolerant taxa tolerant silt of Ratio 0 29/02/2008 M1 M2 M3 M4 M5 DDD2 Site
Figure 10. The observed variation in the silt tolerant taxa ratio values since September, 2002.
Site DDD2 This is the ninth survey of this artificial dam and has generally been precluded from the analysis and discussion of the other sites as they represent flowing water systems and constitute a very different aquatic ecosystem. The dam substrate has changed somewhat since
18 the first survey. In the initial survey the substrate consisted mainly of a thick covering of dead or dieing vegetation made up mostly of grass, which had been submerged as the dam was filled. During the second survey all of the submerged terrestrial vegetation had died and decomposed resulting in a thick layer of organic detritus. With the current survey the organic detritus had been removed resulting in the substrate been composed of sand and gravel on the surface with thick clay/mud underneath. Macrophytes are establishing in the shallow water with sedges starting at approximately 0.5-1.0 metres from the shore followed by floating macrophytes out to approximately 10 metres. This density and variety of macrophyte species adds to the number and complexity of the habitats available within the ecosystem. The riparian zone now contains grasses growing down to the waters edge and starting to overhang the water. This riparian zone is providing good habitat for frogs and invertebrates. However, the presence of cattle has reduced the extent and cover of the grasses with many of the sedges showing signs of grazing.
As this ecosystem has only recently been formed it still largely contains the early colonising, wide-ranging species. However, a new secondary community is becoming well established and includes representatives of the EPT guide. The community is generally composed of predators such as the coleopteran family Hydrophilidae, the Odonata families Libellulidae (Nannophlebia) and Coenagrionidae (Ischnura), the large hemipteran families such as the Notonectidae and Corixidae and the chironomid midges particularly the subfamily Chironominae. All of these taxa are very tolerant of disturbance and poor water quality, although the water quality of this site is generally good. There are now also representatives of the EPT shredder guide including the mayflies (Caenidae) and caddis flies (Leptoceridae) and the filter feeder guild including the shrimp, Paratya australiensis and the bivalve Pisidium. The EPT taxa are present at this site due to the close proximity to the Mammy Johnsons River and a close riparian corridor allowing the dispersal of these taxa to this site. These taxa normally do not disperse far from a riverine environment. Although EPT taxa are generally regarded as disturbance sensitive, the species observed at this site occur over a wide range of habitats, especially those that have the appropriate food sources and relatively good water quality.
Physico-Chemical Data
Survey 13 Units M1 M2 M3 M4 M5 DDD2 Temperature °C 19.9 19.6 19.6 19.4 19.1 22.4 Dissolved Oxygen mg/l 6.9 6.8 6.8 7.3 7.7 3.8 Conductivity MS 245 246 239 233 116 218 pH ph units 8.1 8.0 8.0 8.0 8.1 8.1
Table 5. Physico-chemical data from each site sampled.
All physico-chemical parameters were again remarkably consistent along the length of the study area and all were well above the minimum requirements as set out by the ANZECC and ARMCANZ guidelines (2000). The range and variation of the physico-chemical parameters along the length of the river and over time for the Mammy Johnsons River as well as rainfall figures for the Mammy Johnsons River catchment can be seen in Figures 11-14.
Rainfall (see Figure 11) over the last six months has been more intense and frequent than the previous six months with approximately 690 mm compared with 612.4 mm for the previous six months and 325.6 mm in the previous spring period. Rainfall frequency and magnitude has been increased since the second half of 2007. Over the last six months there have been seventeen rainfall events over 10 mm, eight rainfall events over 20 mm and two events over 30 mm resulting in a lengthened period of high regular flows in the rivers. Most the rainfall occurred in the last three months.
19 2007-2008 Six Monthly Rainfall
60.0 50.0 40.0 30.0 20.0
Rainfall (mm) 10.0 0.0
7 7 7 7 8 0 0 07 07 0 0 0 08 08 0 0 0 0 0 /20 /20 /2007 /2007 /2007 /2 /2 /2 /20 /20 /2 /2 0 1 1 2 2 /09 /1 /1 /1 /12 /12 /01 /01/2008/0 /0 7 0 4 9 2 6 01 15/09 29/09 13/10 2 1 2 08 22 05 1 0 1 date
Figure 11. The observed rainfall totals for the Mammy Johnsons River Catchment, for the last six months from September, 2007 to February, 2008.
The observed temperatures for the current survey (see Figure 12) were similar to the previous March readings and ranged from 19.1°C to 19.9°C for all river sites (Sites M1 – M5) to 22.4°C for Site DDD2.
Water Temperature
35
30 M1 25 M2 20 M3 15 M4 10 M5
Degrees Celsius 5 DDD2 0
3 5 6 002 00 04 004 0 005 006 00 07 2 20 2 20 2 2 20 / / 9/ / / 4/ 9/2 / 09 03 /2 03 0 9 0 0 03 / / / / /0 / 9/ / 03 28 25/09/200319 03/06/200421 10/03 15 07 1 07 29/02/2008 12/09/2007# Sites
Figure 12. The observed variation in water temperature for all sites since September, 2002. Note # indicates data collected by James Benson, see comments in Survey 12.
Conductivity (see Figure 13) was substantially lower than previous surveys for Site DDD2 whereas they were quite comparable in the river sites to previous autumn surveys. It ranged from 115.6 µS/cm at Site M5 on the Karuah River between 232.7µS/cm - 245.4 µS/cm for the Mammy Johnsons River sites. Unlike previous surveys, there is a slight trend of decreasing conductivity downstream in the Mammy Johnsons River indicating that instead if
20 acquiring salt (normally from groundwater intrusion) as the water goes downstream, the river water is being diluted by the addition of rainwater downstream.
Conductivity
800
700 M1 600 M2 500 M3 400 300 M4 200 M5 Microsemens
100 DDD2 0
2 3 3 4 4 4 5 5 6 6 7 # 8 00 00 00 00 00 00 00 00 00 00 00 7 00 2 2 2 2 2 2 2 2 2 2 2 00 2 9/ 3/ 9/ 3/ 6/ 9/ 3/ 9/ 4/ 9/ 3/ /2 2/ /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 9 /0 3 8 5 9 3 1 0 5 7 9 7 /0 9 0 2 2 1 0 2 1 1 0 1 0 12 2 Site
Figure 13. The observed variation in conductivity values for all sites since September, 2002. Note # indicates data collected by James Benson, see comments in Survey 12. pH (see Figure 14) was essentially slightly to mildly alkaline but varied little across all sites ranging from 8.0 to 8.1. The pH has remained very constant over time varying no more than 1 pH unit throughout the monitoring program although there has been a gradual increase (towards alkaline values) since September, 2006.
pH
9 8 M1 7 6 M2 5 M3 4 M4 3 pH Units pH M5 2 1 DDD2 0
3 04 04 05 06 2002 200 2003 0 2004 0 2005 0 2007 2008 /2 /2 /2 /20 2007# 09/ 03/ 09/ 3 06/ 9 03/ 9 04 03/ 02/ /0 /0 /0 / /09/2006 09/ 03/ 28/ 25/ 19 03/ 21 10/ 15 07 19 07/ 29/ 12/ Site
Figure 14. The observed variation in pH values for all sites since September 2002. Note # indicates data collected by James Benson, see comments in Survey 12.
21 Dissolved oxygen (See Figure 15) levels were well above minimum acceptable limits for all sites, as the higher river flows naturally increase turbulence and therefore increase the dissolved oxygen content. The increase in regularity and volume of flows will also increase DO within the pools that often go anoxic during extended periods of low flow.
Dissolved Oxygen
10 9 8 M1 7 M2 6 M3 5
DO 4 M4 3 M5 2 DDD2 1 0
02 3 04 4 4 6 6 00 0 00 0 005 00 0 /20 2 2 9 3/2003 9/2 6/2 3/ 9/2005 4/ 9/20 /2007* 2/2008 /0 03/2 9 3 8/0 5/0 / /0 0/0 7/0 /0 9/0 0 2 2 19 03 21/09/201 15/0 0 19 07/03/200712/0 2 Site
Figure 15. The observed variation in dissolved oxygen values for all sites since September, 2002. Note * indicates data not collected on 12 Sept 2007, see comments in Survey 12.
Site DDD2 The physico-chemical properties of the dam site indicate the pondage has good water quality. Water levels have not changed significantly over the last few years as the dam has remained at the spill pipe level for an extended period allowing for the development of macrophytes and riparian vegetation. Photographs from the previous survey have been included (Photos 13-14) to show the change in macrophyte growth in the dam over the last 6 months. Generally, the water quality parameters of the dam have mirrored those of the rivers although values may be higher or lower. Temperature was higher compared with the other sites at 22.4°C, which is to be expected given the shallow edges and essentially no riparian zone to cover the waters edge. Conductivity has decreased significantly from the previous five surveys but is comparable to the March 2004 survey (Survey 5). The observed reading is very low compared with regional groundwater levels and is considered fresh in the ANZECC and ARMCANZ guidelines (2000). pH was slightly alkaline and lower than most previous surveys. Therefore, the site has relatively high water quality.
Discussion The results of the current survey indicate that both the Mammy Johnsons and Karuah Rivers are still in good to very good condition and possess a highly complex and diverse aquatic ecosystem.
In summary the results show an overall decrease in diversity values in all sites compared with those of the previous survey and comparable to those observed for the same period in 2006. However, the condition indices (SIGNAL, EPT Ratio and Shredder Ratio) mirrored each other and differed from the biodiversity values by showing significant increases in condition
22 values at all sites compared with the previous survey and were also comparable with the same period for the last four years. This is due to a decrease in the numbers of silt tolerant species and the large increase in disturbance sensitive species such the EPT and Shredder trophic groups. These results i.e. the high species diversity and numbers of EPT taxa indicate that the riverine ecosystem values at Sites M1 - M5 are in good to excellent condition. These results are higher than those observed for the previous autumn surveys from 2003 to 2006. This signifies that the community composition has improved in the number of pollution / disturbance sensitive taxa.
Over the last six months there has been a substantial increase in the volume and regularity of rainfall events (particularly over the last 3 months) producing higher regular flow levels in both rivers, maintaining higher water quality and providing a scouring impact on the substrate. The higher flow conditions have increased the scouring effects, which normally remove the accumulated fine sediments, algae and associated invertebrate fauna from the substrate. These increased flows have increased the amount of available habitat for the associated grazer and shredder fauna and made the allochthonous material a more readily accessible food supply by increasing the conditioning and breakdown of the material. The results have registered a substantial increase in overall ecosystem condition and an apparent increase in the proportion of EPT and grazer components in the community. However, as the number of species has remained relatively constant over the last two surveys, this apparent increase in ecosystem health is partially due to a reduction in the numbers of silt and disturbance tolerant taxa, which were removed by the scouring effects of the recent floods. There will, however, be a time lag of at least 6 to 12 months before substantial ecosystem benefits can be registered through an increase in biodiversity due to the time it takes for the lifecycles of the aquatic invertebrates to be completed. If conditions of flow and water quality remain favourable, the current season’s nymphs and larvae will be able to reproduced in numbers and replenish the community.
The seasonality of the normal lifecycle for most of the EPT taxa (as well as the majority of other aquatic insects) does impact on the apparent biodiversity of a river system. The lifecycles of aquatic invertebrates involves the development of the aquatic larvae over the winter months with mature larval emerging as adults from late spring to late summer resulting in an apparent increase in numbers of animals and species during this early spring period. This contrasts with the late summer period where many adults have left the water and larvae are young, small and highly cryptic (i.e. they live in the hyporheic zone / under the gravel substrate). This results in an apparent reduction in biodiversity and abundance and is reflected in the lower diversity of the EPT groups.
The two main factors influencing the biological diversity and water chemistry are flow and landscape condition i.e. riparian zone condition. Flow is one of the main regulatory factors that determine biological activity and diversity within rivers, particularly in high-energy coastal systems. Aquatic communities are susceptible to change, in both numbers of organisms and community composition during periods of extreme flow conditions such as the rapid changes seen during high flows or the gradual change seen during low or no flows. Each extreme flow regime will produce flow conditions favourable to particular segments of the community and these components will then increase in numbers. The second major factor that has contributed to the high biodiversity and high water quality of both the Karuah and Mammy Johnsons River systems is the intact, native riparian vegetation found along the banks of the rivers and the mature upland native forests. The lack of excessive sedimentation from erosion of the catchment and riverbanks has allowed a range of niches in the riverbed to be retained allowing the aquatic community to maintain a high diversity and efficiency in processing the nutrients and allochthonous matter that enters the system. This in turn produces higher water quality for all uses.
Overall, there has been a consistent number of taxa and a reduction in silt tolerant taxa and an apparent increase in EPT taxa resulting in a substantial increase in condition at all Mammy Johnson sites. Although there has been an overall increase in condition of the two river
23 systems there was significant variability among the sites, often with contradicting results such as the decrease in biodiversity within Site M2. There are four possible causes for this variability: i) differences in site geomorphology and river size; ii) variations in the habitat produced by the different flow regimes; iii) differences in the composition of the faunal communities associated with each particular type of river flow regime and iv) the seasonal life cycle differences of the different community components.
Therefore, the result of the current survey confirms what has previously been predicted and demonstrated, i.e. that the aquatic biodiversity is continuing to show the same or similar trends to that observed in previous years. The continued high regular flows have stimulated the numbers of EPT and shredder taxa recorded at all sites (15 - 19 taxa) indicating that all sites are very healthy and showing no signs of environmental stress.
In conclusion, the results from the current survey suggest that the overall biodiversity and river environmental conditions are very good and that there are no apparent adverse effects on the aquatic macroinvertebrate fauna as a result of any activities arising from the operations of the Duralie Mine.
Acknowledgements We are grateful to Mr. John Trotter for his continued assistance in the field and James Benson for providing background information on water quality and site history.
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24 Resh, V.H. and Jackson, J.K. 1993. Rapid assessment approaches to biomonitoring using benthic macroinvertebrates. In: Freshwater Biomonitoring and Benthic Macroinvertebrates. Eds Rosenburg, D.M. and Resh, V.H. Chapman & Hall, New York, 195-223.
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Williams, W.D. 1981. Australian Freshwater Life. The Invertebrates of Australian Inland Waters. Macmillan Education Australia Pty Ltd. Melbourne.
25 Appendix 1 A list of the macroinvertebrate species collected at the six sample sites on the Mammy Johnsons and the Karuah Rivers on the29th February 2008.
Order Family Species M1 M2 M3 M4 M5 DDD2 Acarina Hygrobatidae undetermined * Bivalvia Sphaeridae Pisidium * * * * * * Coleoptera Dystiscidae Chostonectes * * Coleoptera Dystiscidae Necterosoma * Coleoptera Elmidae Austrolimnius * * * * * Coleoptera Elmidae Kingolus * Coleoptera Elmidae Simsonia * * * * Coleoptera Gyrinidae Macrogyrus * * Coleoptera Haliplidae Haliplus * * * * Coleoptera Hydrophilidae Berosus * * * * Coleoptera Psephenidae Sclerocyphon maculatus * * * * Decapoda Atyidae Australatya striolata * Decapoda Atyidae Paratya australiensis * * * * * * Diptera Ceratopogonidae Bezzia * * Diptera Chironomidae Chironominae * * * * Diptera Chironomidae Orthocladinae * * * * * Diptera Chironomidae Tanypodinae * * * * * Diptera Dixidae Dixa * Diptera Tanyderidae Tanyderus * Diptera Tipulidae sp. * * Ephemeroptera Baetidae Bungona sp. 1 * * * * * * Ephemeroptera Baetidae Bungona sp. 2 * * * Ephemeroptera Caenidae Tasmanocoenis * * * Ephemeroptera Ameletopsidae Mirawara sp. * Ephemeroptera Leptophlebiidae Atalophlebia sp. AV12 * * * Ephemeroptera Leptophlebiidae Austrophlebioides sp. AV9 * * * * * Ephemeroptera Leptophlebiidae Jappa * * Ephemeroptera Leptophlebiidae Nousia * * * * Gastropoda Ancylidae Ferrissia petterdi * * Gastropoda Hydrobiidae Posticobia brazieri * * * * Gastropoda Planorbidae Glyptophysa * Gastropoda Planorbidae Gyraulus * * Gastropoda Planorbidae Isidorella * Hemiptera Corixidae Agraptocorixa * Hemiptera Gerridae Limnogonus * * Hemiptera Naucoridae Naucoris * Hemiptera Notonectidae Anisops * Hemiptera Notonectidae Enithares * Hemiptera Pleidae Plea * Hemiptera Veliidae Microvelia * * Hirudinea Glossiphoniidae Undetermined * Megaloptera Corydalidae Archichauliodes guttiferus * * * * * Odonata Coenagrionidae Ischnura heterosticta * Odonata Gomphidae Hemigomphus * Odonata Hemicorduliidae Hemicordulia * Odonata Libellulidae Diplacodes * Oligochaete Lumbriculidae Lumbricus variegatus * * * Oligochaete Tubificidae Undetermined * * * *
26 Plecoptera Grypopterygidae Illiesoperla brevicauda * * * * * Trichoptera Calamoceratidae Anisocentropus * * * * * Trichoptera Conoesucidae Coenoria sp. AV1 * Trichoptera Ecnomidae Ecnomus * * * Trichoptera Helicopsychidae Helicopsyche * Trichoptera Hydrobiosidae Apsilochorema * * * * * Trichoptera Hydropsychidae Cheumatopsyche sp.AV1 * * * * * Trichoptera Leptoceridae Notalina spira * * Trichoptera Leptoceridae Oecetis * * * * Trichoptera Leptoceridae Triplectides ciuskus cuiskus * * Trichoptera Leptoceridae Triplectides volda * Trichoptera Philopotamidae Chimarra * * * * Trichoptera Philopotamidae Hydrobiosella * * Acarina Hygrobatidae undetermined * Bivalvia Sphaeridae Pisidium * * * * * * Coleoptera Dystiscidae Chostonectes * * Coleoptera Dystiscidae Necterosoma * Coleoptera Elmidae Austrolimnius * * * * * Coleoptera Elmidae Kingolus * Coleoptera Elmidae Simsonia * * * * Coleoptera Gyrinidae Macrogyrus * * Coleoptera Haliplidae Haliplus * * * * Coleoptera Hydrophilidae Berosus * * * * Coleoptera Psephenidae Sclerocyphon maculatus * * * * Decapoda Atyidae Australatya striolata * Decapoda Atyidae Paratya australiensis * * * * * * Diptera Ceratopogonidae Bezzia * * Diptera Chironomidae Chironominae * * * * 44 61 M1 M2 M3 M4 M5 DDD2 No of Families 25 18 20 20 24 23 No of Genera 31 22 26 28 29 28 SIGNAL - HU97B 5.8 6.8 6.4 6.4 6.7 5.0 EPT 12 12 11 12 14 6 EPT ratio 0.39 0.55 0.42 0.43 0.48 0.21 Shredder Ratio 0.58 0.68 0.62 0.64 0.66 0.32 Silt Tolerant Taxa 7 2 2 4 4 5 Silt Tolerant Taxa Ratio 0.23 0.09 0.08 0.14 0.14 0.18
27 Duralie Coal Pty Ltd Duralie Coal Mine
DUST MONITORING
Annual Environmental Management Report September2008 Duralie Coal Pty Ltd
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Annual Environmental Management Report September 2008 Duralie Coal Pty Ltd Duralie Coal Mine
GROUNDWATER
Annual Environmental Management Report September2008 DB1W
Parameter Units 29-Nov-07 20-Mar-08 27-May-08 28-Aug-08 Min Avg Max Variance Std Dev Depth to standing WL (m) 15.66 15.67 15.58 15.72 15.58 15.66 15.72 0.00 0.06 pH 7.0 7.6 5.4 6.2 5.4 6.6 7.6 0.9 1.0 Conductivity @ 250C (µS/cm) 2400 2700 2000 4300 2000 2850 4300 1016667 1008 ORP mV 35 - 179 52 35 89 179 6192 79 Alkalinity as CaCO3 (mg/L) 77 0 1 117 0 49 117 3371 58 Acidity as CaCO3 (mg/L) 106 189 144 112 106 138 189 1446 38 Sulphate (mg/L) 290 227 212 321 212 263 321 2663 52 Chloride (mg/L) 1360 928 647 1700 647 1159 1700 216196 465 Calcium (mg/L) 269 122 57 287 57 184 287 12602 112 Magnesium (mg/L) 69 57 40 72 40 60 72 211 15 Sodium (mg/L) 327 410 599 327 445 599 19432 139 Aluminium (mg/L) 0.22 3.36 10.60 0.18 0.18 3.59 10.60 24.06 4.91 Iron (Dissolved) (mg/L) 28.1 0.5 1.6 31.3 0.5 15.4 31.3 275.4 16.6 Manganese (mg/L) 1.0 1.2 0.8 1.1 0.8 1.0 1.2 0.0 0.2 Zinc (mg/L) 0.05 0.18 0.27 0.05 0.05 0.14 0.27 0.01 0.11 DB2W
Parameter Units 29-Nov-07 20-Mar-08 27-May-08 28-Aug-08 Min Avg Max Variance Std Dev Depth to standing WL (m) 20.19 20.12 20.07 20.28 20.07 20.17 20.28 0.01 0.09 pH 8.0 8.0 6.5 6.4 6.4 7.2 8.0 0.8 0.9 Conductivity @ 250C (µS/cm) 1000 1000 1200 1110 1000 1078 1200 9358 97 ORP mV -30 - 18 20 -30 3 20 801 28 Alkalinity as CaCO3 (mg/L) 144 121 144 133 121 136 144 120 11 Acidity as CaCO3 (mg/L) 112 53 74 47 47 72 112 863 29 Sulphate (mg/L) 151 151 121 171 121 149 171 425 21 Chloride (mg/L) 156 219 236 236 156 212 236 1446 38 Calcium(mg/L)82789187788591326 Magnesium(mg/L)2121262321232662 Sodium (mg/L) 119 115 130 115 121 130 60 8 Aluminium (mg/L) <0.01 0.36 1.7 <0.01 <0.01 1.7 0.9 0.9 Iron (Dissolved) (mg/L) 3.3 <0.05 <0.05 14.7 <0.05 14.7 64.5 8.0 Manganese (mg/L) 1.0 1.0 1.5 1.1 1.0 1.1 1.5 0.0 0.2 Zinc (mg/L) 0.006 0.029 0.054 0.008 0.006 0.024 0.054 0.001 0.022 DB3W
Parameter Units 29-Nov-07 19-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 3.27 2.88 2.40 2.76 2.40 2.83 3.27 0.13 0.36 pH 7.8 8.6 6.5 6.9 6.5 7.5 8.6 0.9 0.9 Conductivity @ 250C (µS/cm) 130 130 110 130 110 125 130 100 10 ORP (mV) -140 - 142 102 -140 35 142 23281 153 Alkalinity as CaCO3(mg/L)323431363133365 2 Acidity as CaCO3 (mg/L) 18 17 32 5 5 18 32 122 11 Sulphate(mg/L)655555601 Chloride (mg/L) 20 31 12 18 12 20 31 61 8 Calcium(mg/L)112111201 Magnesium(mg/L)112111201 Sodium (mg/L) 19 16 20 16 18 20 4 2 Aluminium (mg/L) 74 43 86 174 43 94 174 3168 56 Iron (Dissolved) (mg/L) 106.0 <0.05 <0.05 3.6 <0.05 106 5239 72 Manganese (mg/L) 0.962 0.61 0.967 1.37 0.61 0.98 1.37 0.10 0.31 Zinc (mg/L) 0.343 0.152 0.356 0.568 0.152 0.355 0.220 0.010 0.100 DB4W
Parameter Units 29-Nov-07 20-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 12.00 11.74 11.73 11.54 11.54 11.75 12.00 0.04 0.19 pH 8.5 7.7 6.7 6.9 6.7 7.5 8.5 0.7 0.8 Conductivity @ 250C (µS/cm) 2100 2800 3290 3070 2100 2815 3290 267367 517 ORP mV 25 - -103 115 -103 12 115 12001 110 Alkalinity as CaCO3 (mg/L) 297 249 259 279 249 271 297 456 21 Acidity as CaCO3 (mg/L) 66 8 65 19 8 40 66 922 30 Sulphate (mg/L) 102 126 134 122 102 121 134 185 14 Aluminium (mg/L) 0.01 0.02 0.18 <0.01 <0.01 0.18 0.01 0.10 Chloride (mg/L) 929.5 938 934 1040 930 960 1040 2830 53 Calcium (mg/L) 139 128 138 129 128 134 139 34 6 Magnesium (mg/L) 53 52 58 52 52 54 58 8 3 Sodium (mg/L) 484 493 519 484 499 519 330 18 Iron (Dissolved) (mg/L) 0.12 <0.05 <0.05 0.35 <0.05 0.35 0.03 0.16 Manganese (mg/L) 1.04 1.25 1.19 0.985 0.99 1.12 1.25 0.02 0.12 Zinc (mg/L) <0.005 0.018 0.02 <0.005 <0.005 0.02 0.00 0.00 DB5W
Parameter Units 29-Nov-07 20-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 12.29 11.82 11.64 11.69 11.64 11.86 12.29 0.09 0.30 pH 8.7 8.1 5.9 5.9 5.9 7.2 8.7 2.1 1.5 Conductivity @ 250C (µS/cm) 2200 2600 2700 3440 2200 2735 3440 267567 517 ORP mV -170 - 139 86 -170 18 139 27304 165 Alkalinity as CaCO3 (mg/L) - 0 1 31 0 11 31 310 18 Acidity as CaCO3 (mg/L) 269 163 158 225 158 204 269 2821 53 Sulphate (mg/L) 375 256 219 402 219 313 402 7950 89 Chloride (mg/L) 1067 896 821 1200 821 996 1200 29094 171 Calcium(mg/L)54554850485255113 Magnesium (mg/L) 68 57 50 68 50 61 68 78 9 Sodium (mg/L) 432 414 589 414 478 589 9266 96 Aluminium (mg/L) 0.01 0.75 0.20 0.08 0.01 0.26 0.75 0.11 0.34 Iron (Dissolved) (mg/L) 20.6 3.37 8.06 88.5 3.4 30.1 88.5 1567.0 39.6 Manganese (mg/L) 2.76 2.31 1.86 2.19 1.86 2.28 2.76 0.14 0.37 Zinc (mg/L) 0.074 0.109 0.034 0.104 0.070 0.078 0.090 0.000 0.010 DB6W
Parameter 29-Nov-07 20-Mar-08 26-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL 20.64 20.48 20.62 19.97 19.97 20.43 20.64 0.10 0.31 pH 7.5 8.2 6.8 6.7 6.7 7.3 8.2 0.5 0.7 Conductivity @ 250C 2400 4600 5710 5240 2400 4488 5710 2143692 1464 ORP -865 - 136 51 -865 -226 136 308047 555 Alkalinity as CaCO3 684 596 639 666 596 646 684 1464 38 Acidity as CaCO3 109 84 112 38 38 86 112 1171 34 Sulphate 93 94 85 89 85 90 94 17 4 Chloride 1546 1709 1750 2110 1546 1779 2110 56530 238 Calcium 302 292 269 293 269 289 302 198 14 Magnesium 197 202 197 197 197 198 202 6 3 Sodium 636 636 684 636 652 684 768 28 Aluminium 0.02 0.67 0.21 0.03 0.02 0.23 0.67 0.09 0.30 Iron (Dissolved) 2.58 <0.05 <0.05 1.88 <0.05 2.58 0.24 0.49 Manganese 0.292 0.399 0.351 0.306 0.292 0.337 0.399 0.002 0.048 Zinc 0.009 0.042 0.009 0.008 0.008 0.017 0.042 0.000 0.017 DB7W
Parameter Units 29-Nov-07 19-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 10.28 9.65 9.41 10.23 9.41 9.98 10.33 0.18 0.42 pH 6.9 7.7 6.9 7.0 6.8 7.1 7.7 0.1 0.4 Conductivity @ 250C (µS/cm) 1800 2000 2930 2810 1800 2424 2930 249630 500 ORP mV 10 - -82 -68 -82 -46 10 1640 40 Alkalinity as CaCO3 (mg/L) 398 352 375 368 352 373 398 365 19 Acidity as CaCO3(mg/L)6434372828416425416 Sulphate (mg/L) 137 132 129 75 75 118 137 842 29 Chloride (mg/L) 714 792 806 860 714 793 860 3633 60 Calcium (mg/L) 167 159 132 157 132 154 167 229 15 Magnesium(mg/L)606057615760613 2 Sodium (mg/L) 392 408 436 392 412 436 496 22 Aluminium (mg/L) 64.9 14.8 28.7 22.2 14.8 32.7 64.9 494.5 22.2 Iron (Dissolved) (mg/L) 51.1 <0.05 <0.05 0.65 <0.05 51.1 1272.6 35.7 Manganese (mg/L) 1.49 1.02 0.917 0.852 0.85 1.07 1.49 0.08 0.29 Zinc (mg/L) 0.203 0.057 0.071 0.068 0.057 0.100 0.203 0.005 0.069 BH4BW
Parameter Units 29-Nov-07 19-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 4.45 4.36 4.15 4.29 4.15 4.31 4.45 0.02 0.13 pH 7.8 8.0 6.3 6.3 6.3 7.1 8.0 0.9 0.9 Conductivity @ 250C (µS/cm) 280 250 200 245 200 244 280 1090 33 ORP mV -50 - 228 107 -50 95 228 19429 139 Alkalinity as CaCO3 (mg/L) 69 101 61 82 61 78 101 305 17 Acidity as CaCO3 (mg/L) 35 51 46 14 14 37 51 270 16 Sulphate (mg/L) 21 12 13 28 12 19 28 56 8 Chloride (mg/L) 39 63 22 29 22 38 63 320 18 Calcium (mg/L) 14 9 9 12 9 11 14 6 2 Magnesium (mg/L) 10 7 6 8 6 8 10 3 2 Sodium (mg/L) 27 23 26 23 25 27 4 2 Aluminium (mg/L) 67 55 93 40 40 64 93 492 22 Iron (Dissolved) (mg/L) 97.8 0.1 <0.05 1.1 <0.05 97.8 3151.5 56.1 Manganese (mg/L) 3.5 1.9 2.3 1.4 1.4 2.2 3.5 0.8 0.9 Zinc (mg/L) 0.51 0.227 0.38 0.162 0.16 0.32 0.51 0.02 0.16 SI1W
Parameter Units 29-Nov-07 19-Mar-08 27-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 10.65 10.60 10.44 10.51 10.44 10.55 10.65 0.01 0.09 pH 7.9 7.8 7.4 7.4 7.4 7.6 7.9 0.1 0.3 Conductivity @ 250C (µS/cm) 1070 1250 1395 1357 1070 1268 1395 21193 146 ORP mV 57 - 171 148 57 125 171 3634 60 Alkalinity as CaCO3 (mg/L) 454 430 438 435 430 439 454 108 10 Acidity as CaCO3 (mg/L) 37 14 23 14 14 22 37 118 11 Sulphate (mg/L) 96 95 90 100 90 95 100 17 4 Chloride (mg/L) 205 180 183 180 189 205 186 14 Calcium(mg/L)84756379637584809 Magnesium (mg/L) 67 65 64 66 64 66 67 2 1 Sodium (mg/L) 137 134 149 134 140 149 63 8 Aluminium (mg/L) 0.01 0.5 2.6 2.09 0.0 1.3 2.6 1.5 1.2 Iron (Dissolved) (mg/L) 0.06 <0.05 <0.05 <0.05 <0.05 0.06 #DIV/0! #DIV/0! Manganese (mg/L) <0.001 0.025 0.16 0.11 <0.001 0.16 0.00 0.07 Zinc (mg/L) 0.01 0.017 0.014 0.068 0.01 0.03 0.07 0.00 0.03 SI2W
Parameter Units 29-Nov-07 20-Mar-08 26-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 25.73 25.55 25.41 25.84 25.41 25.63 25.84 0.04 0.19 pH 7.8 8.1 7.0 7.3 7.0 7.6 8.1 0.2 0.5 Conductivity @ 250C (µS/cm) 1220 1350 1000 1097 1000 1167 1350 23029 152 ORP mV -160 - 303 12 -160 52 303 54772 234 Alkalinity as CaCO3 (mg/L) 247 273 272 285 247 269 285 255 16 Acidity as CaCO3(mg/L)1914461414234623615 Sulphate (mg/L) 145 446 46 192 46 207 446 29037 170 Chloride (mg/L) 274 42 72 106 42 123 274 10754 104 Calcium (mg/L) 74 120 79 68 68 85 120 557 24 Magnesium (mg/L) 30 66 44 33 30 43 66 266 16 Sodium (mg/L) 168 115 152 115 145 168 739 27 Aluminium (mg/L) <0.01 2.98 1.49 0.90 0.90 1.79 2.98 1.15 1.07 Iron ()(Dissolved)(g) (mg/L) 0.3 0.07 <0.05 0.46 <0.05 0.5 0.0 0.2 Manganese (mg/L) 0.083 0.414 0.319 0.277 0.083 0.273 0.414 0.019 0.139 Zinc (mg/L) 0.011 0.105 0.044 0.11 <0.01 0.020 0.000 0.006 SI3W
Parameter Units 29-Nov-07 19-Mar-08 26-May-08 28-Aug-08 Min Avg Max Var Std Dev Depth to standing WL (m) 27.44 27.26 27.68 28.08 27.26 27.62 28.08 0.13 0.35 pH 8.3 7.4 7.1 no sample 7.1 7.6 8.3 0.4 0.6 Conductivity @ 250C (µS/cm) 2700 4900 6480 2700 4693 6480 3604133 1898 ORP mV -30 - 303 -30 137 303 55445 235 Alkalinity as CaCO3 (mg/L) 462 430 450 430 447 462 261 16 Acidity as CaCO3 (mg/L) 71 56 74 56 67 74 93 10 Sulphate (mg/L) 208 201 185 185 198 208 139 12 Chloride (mg/L) 1986 2157 2160 1986 2101 2160 9921 100 Calcium (mg/L) 463 459 450 450 457 463 44 7 Magnesium (mg/L) 135 142 132 132 136 142 26 5 Sodium (mg/L) 832 777 777 805 832 1513 39 Aluminium (mg/L) 6.31 5.33 12.5 5.3 8.0 12.5 15.1 3.9 Iron ()(Dissolved)(g) (mg/L) 3.6 <0.05 <0.05 <0.05 3.6 #DIV/0! #DIV/0! Manganese (mg/L) 0.636 0.509 0.933 0.509 0.693 0.933 0.047 0.218 Zinc (mg/L) 0.115 0.072 0.133 <0.01 0.150 0.004 0.064 1 R .10V``Q%JR1: V`7Q`V.#5.:J$V
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Duralie Coal Pty Ltd Duralie Coal Mine
IRRIGATION
Annual Environmental Management Report September2008 Soil Salinity and pH Monitoring
Coordinates: 399560;6425388 - Run 8 Type II irrigation area
Parameter Units 12-Aug-05 17-Aug-06 17-Aug-07 1-Sep-08 Run 8 Avg REF Avg** pH 5.5 6.5 6.5 7.0 6 6.3 Moisture % 24 21 26.4 - 24 23 Bicarb Alkalinity % 1.5 6.2 89.5 146 61 82 Sulphate mg/kg 130 370 1000 620 530 147 Chloride mg/kg 40 260 165 150 154 45 Calcium mg/kg 3407 5900 5800 120 3807 2324 Magnesium mg/kg 899 3900 3600 40 2110 2544 Sodium mg/kg 209 540 490 220 365 161
** REF Avg = average of "Reference" sampling site.
Coordinates: 399570;6426001 - Run 10 Type II irrigation area
Parameter Units 12-Aug-05 17-Aug-06 17-Aug-07 1-Sep-08 Run 10 Avg REF Avg** pH 5.5 6.5 6.5 6.5 6 6.3 Moisture % 23 33 21.6 26 23 Bicarb Alkalinity % 1.8 6.2 89.5 110 52 82 Sulphate mg/kg 500 74 700 360 409 147 Chloride mg/kg <25 25 25 50 33 45 Calcium mg/kg 3808 8000 7500 80 4847 2324 Magnesium mg/kg 705 4000 4200 20 2231 2544 Sodium mg/kg 221 530 490 130 343 161
Coordinates: 399165;6426056 - Run 16 Type II irrigation area
Parameter Units 12-Aug-05 17-Aug-06 17-Aug-07 1-Sep-08 Run 16 Avg REF Avg** pH 5 5.5 5.5 5 5 6.3 Moisture%283131 3023 Bicarb Alkalinity % <0.1 5.3 60 43 36 82 Sulphate mg/kg 180 100 830 500 403 147 Chloride mg/kg 50 100 212 100 116 45 Calcium mg/kg 501 760 940 60 565 2324 Magnesium mg/kg 374 510 540 40 366 2544 Sodium mg/kg 186 260 370 170 247 161
Coordinates: 399996;6425269 - Reference - southern side of mine access road (between N'cle Uni markers)
Parameter Units 12-Aug-05 17-Aug-06 17-Aug-07 01-Sep-08 Average pH 5.5 6.0 6.5 7.0 6 Moisture % 30 20.6 19.4 23 Bicarb Alkalinity % 1.8 6.2 89.5 232 82 Sulphate mg/kg 160 49 340 40 147 Chloride mg/kg 25 100 <25 10 45 Calcium mg/kg 3407 5100 4400 30 3234 Magnesium mg/kg 1155 4900 4100 20 2544 Sodium mg/kg 124 260 230 30 161 Soil Salinity and pH Monitoring
Coordinates: 399499;6428239 - Run 31 Type III irrigation area
Parameter Units 4-Jan-06 17-Aug-06 17-Aug-07 1-Sep-08 Run 31 Avg REF Avg** pH 5 6 5.5 6 6 6 Moisture % 29.8 22.8 26 23 Bicarb Alkalinity % 5.6 60 73 46 82 Sulphate e mg/kg 220 100 430 60 203 147 Chloride mg/kg 680 25 25 30 190 45 Calcium e mg/kg 670 1000 1200 20 723 2324 Magnesium e mg/kg 470 500 400 <10 457 2544 Sodium e mg/kg 60 210 250 50 143 161
** REF Avg = average of "Reference" sampling site.
Coordinates: 399951;6428609 - Run 32 Type III irrigation area
Parameter Units 4-Jan-06 17-Aug-06 17-Aug-07 1-Sep-08 Run 32 Avg REF Avg** pH 5 6 8 6.5 6 6 Moisture % 31.5 30.7 31 23 Bicarb Alkalinity % 5.8 209 73 96 82 Sulphate e mg/kg 140 67 660 100 242 147 Chloride mg/kg 310 37 118 20 121 45 Calcium e mg/kg 970 1070 2100 20 1040 2324 Magnesium e mg/kg 780 640 760 <10 727 2544 Sodium e mg/kg 120 270 310 80 195 161
Coordinates: 399631;6428734 - Run 35 Type III irrigation area
Parameter Units 4-Jan-06 17-Aug-06 17-Aug-07 1-Sep-08 Run 35 Avg REF Avg** pH 7 7 8 6.5 7 6 Moisture % 26.1 28.2 27 23 Bicarb Alkalinity % 6.7 149.5 61 72 82 Sulphate e mg/kg 270 140 1300 140 463 147 Chloride mg/kg 990 130 70.5 40 308 45 Calcium e mg/kg 2900 4600 7600 40 3785 2324 Magnesium e mg/kg 480 330 520 <10 443 2544 Sodium e mg/kg 170 200 330 80 195 161 Duralie Coal Pty Ltd Duralie Coal Mine
NATIONAL POLLUTANT INVENTORY
Annual Environmental Management Report September2008