HELLYER MINE PROJECT (Fossey Zone) - EPA Tasmaniaepa.tas.gov.au/documents/bass_metals_hellyer_mine... · Acute Toxicity of a Mine Wastewater and Reference Toxicants to the Tasmanian

BASS METALS LTD HELLYER MINE PROJECT (Fossey Zone)

DEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLAN Volume 4 – Appendix 3 October 2009

HMP - DPEMP BSM September 2009

Appendix H – Aquatic Science – Acute Toxicity of a Mine Wastewater and Reference Toxicants to the Tasmanian Cladoceran Ceriodaphnia spinata

Acute Toxicity of a Mine Wastewater and Reference Toxicants to the Tasmanian Cladoceran Ceriodaphnia spinata

Aquatic Scienceon behalf Bass Metals

Test Report

January 2008

Acute Toxicity of a Mine Wastewater and Reference Toxicants to the Tasmanian Cladoceran Ceriodaphniaspinata

Aquatic Science on behalf Bass Metals

Test Report

April 2009

Toxicity Test Report: TR0427/1 (page 1 of 2)

Client: Aquatic Science Pty Ltd ESA Job #: PR0427 122 Karratha Drive Date Sampled: 6 November 2008 Sandford TAS 7020 Date Received: 9 December 2009 Attention: Daniel Ray Sampled By: Client Client Ref: Quote #: PL0427_q01

Lab ID No.: Sample Name: Sample Description:3193 ‘Bulgobac 7-11-08 @ 8:00’ Surface Water, pH 7.8, conductivity 56 μS/cm

Test Performed: 48-hr acute (survival) toxicity test using the freshwater cladoceran Ceriodaphnia spinata sourced from the west coast of Tasmania

Test Protocol: ESA SOP 101, based on USEPA (2002) Deviations from Protocol: Cladocerans were cultured in surface water collected from Lake

Pieman, Tasmania, and then over 4 weeks prior to testing, in Bulgobac water (sample 3193). Cultures were maintained at 18±1oC and fed a combination of unicellular algae (Selenastrum capricornutum) and a mixture of yeast, cerophyll, and trout chow. Otherwise culture techniques same as for Ceriodaphnia dubia.Test concentrations were prepared in Bulgobac water (sample 3193).

Source of Test Organisms: ESA Laboratory culture, sourced from the west coast of Tasmania, subsequently identified by the client as Ceriodaphnia spinata

Test Initiated: 13 January 2009 at 1900 h.

Sample 3193 spiked with AR grade zinc chloride

Vacant Vacant

Nominal Zn Concentration

(�g Zn/L)

% Survival (at 48 hr)

0 (control) 100 � 0.0125 100 � 0.0250 100 � 0.0500 85.0 � 10.0

1000 0.0 � 0.02000 0.0 � 0.0

48 hr EC50 = 637.3 (570.5-711.9) �g/L (TSK trim value = 0.0%) NOEC = 500�g/LL LOEC = 1000�g/L


QA/QC Parameter Criterion This Test Criterion met?Control % survival >90 % 100% Yes Test Temperature limits 18.0 � 1 oC 18.0ºC Yes

Test Report Authorised by: Dr Rick Krassoi Director, on 15 April 2009

Results are based on the samples in the condition as received by ESA



Lab ID No.: Sample Name: Sample Description:3193 ‘Bulgobac 7-11-08 @ 8:00’ Surface Water, pH 7.8, conductivity 56 μS/cm 3194 ‘Jeds Spring water (treated) sampled 6-

11-08 @ 17:30’ Treated Ground Water, pH 7.1, conductivity 2670 μS/cm



Pieman, Tasmania, and then over 4 weeks prior to testing, in Bulgobac water (sample 3193). Cultures were maintained at 18±1oC and fed a combination of unicellular algae (Selenastrum capricornutum) and a mixture of yeast, cerophyll, and trout chow. Otherwise culture techniques same as for Ceriodaphnia dubia.Test concentrations of Jeds Spring water (sample 3194) were prepared by serially diluting with Bulgobac water (sample 3193). Given the high conductivity of the Jeds Spring sample compared with the Bulgobac culture water, conductivity controls were prepared by the addition of GP-2 artificial salts to Bulgobac water using a magnetic stirrer. A sub-sample of undiluted Bulogobac and Jeds Spring water were collected and sent to Advanced Analytical Australia for a range of chemical analyses (refer to report A09/1074-A, A09/1074-B attached)


Test Initiated: 30 March 2009 at 1900 h.

Sample 3194 (Jeds Spring) diluted with sample 3193 (Bulgobac)

Conductivity Controls (prepared in sample 3193 Bulgobac water)

Concentration (%) % Survival (at 48 hr)

Treatment % Survival (at 48 hr)

0 (control) 100 � 0.0 Bulgobac (56 μS/cm) 100 � 0.06.25 100 � 0.0 Bulgobac (1500 μS/cm) 100 � 0.012.5 100 � 0.0 Bulgobac (2670 μS/cm) 0.0 � 0.025 100 � 0.050 100 � 0.0

100 0.0 � 0.0

48 hr IC50 = 70.8 (70.8-70.8) % (non-linear interpolation) NOEC = 50% LOEC = 100%







Lab ID No.: Sample Name: Sample Description:3193 ‘Bulgobac 7-11-08 @ 8:00’ Surface Water, pH 7.8, conductivity 56 μS/cm



Pieman, Tasmania, and then over 4 weeks prior to testing, in Bulgobac water (sample 3193). Cultures were maintained at 18±1oC and fed a combination of unicellular algae (Selenastrum capricornutum) and a mixture of yeast, cerophyll, and trout chow. Otherwise culture techniques same as for Ceriodaphnia dubia.Test concentrations were prepared in Bulgobac water (sample 3193). Sub-samples of each test treatment were collected and shipped to Advanced Analytical Australia for analysis of dissolved zinc concentrations. The concentrations of zinc are reported as measured.


Test Initiated: 1 April 2009 at 1900 h.

Sample 3193 spiked with AR grade zinc chloride

Vacant Vacant

Measured Zn Concentration*

(mg Zn/L)

% Survival (at 48 hr)

0 (control) 100 � 0.01.2 35.0 � 19.2**2.4 0.0 � 0.04.9 0.0 � 0.09.8 0.0 � 0.019 0.0 � 0.0

48 hr IC50 = 1.1 (0.9-1.3) mg Zn/L (non-linear interpolation) NOEC = <1.2mg Zn/L LOEC = 1.2mg Zn/L * Refer to Advanced Analytical Australia test report A09/1074-A attached. ** Significantly fewer surviving neonates compared with Bulgobac water control (heteroscedastic t-test, 1-tail, P=0.05)





Chain-of-Custody Documentation

Statistical Analyses of Toxicity Test Data

Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 13/01/2009 19:00 Test ID: PR427/1 Sample ID: ZINC IN BUEnd Date: 15/01/2009 19:00 Lab ID: 3193 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Zinc chloride spiked into Bulgobac water- Nominal concentrations

Conc-ug/L 1 2 3 4ulgobac Control 1.0000 1.0000 1.0000 1.0000

125 1.0000 1.0000 1.0000 1.0000250 1.0000 1.0000 1.0000 1.0000500 0.8000 0.8000 1.0000 0.8000

1000 0.0000 0.0000 0.0000 0.00002000 0.0000 0.0000 0.0000 0.0000

Transform: Arcsin Square Root Rank 1-Tailed NumberConc-ug/L Mean N-Mean Mean Min Max CV% N Sum Critical Resp

ulgobac Control 1.0000 1.0000 1.3453 1.3453 1.3453 0.000 4 0125 1.0000 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 0250 1.0000 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 0500 0.8500 0.8500 1.1667 1.1071 1.3453 10.206 4 12.00 10.00 3

1000 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 202000 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 20

Auxiliary Tests Statistic Critical SkewShapiro-Wilk's Test indicates non-normal distribution (p <= 0.01) 0.564851 0.844 2.555506Equality of variance cannot be confirmedHypothesis Test (1-tail, 0.05) NOEC LOEC ChV TUSteel's Many-One Rank Test 500 1000 707.1068

Trimmed Spearman-KarberTrim Level EC50 95% CL

0.0% 637.28 570.51 711.875.0% 651.24 572.08 741.36

10.0% 661.21 558.88 782.2920.0% 665.16 616.11 718.11

Auto-0.0% 637.28 570.51 711.87

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Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 13/01/2009 19:00 Test ID: PR427/1 Sample ID: ZINC IN BUEnd Date: 15/01/2009 19:00 Lab ID: 3193 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Zinc chloride spiked into Bulgobac water- Nominal concentrations

Auxiliary Data SummaryConc-ug/L Parameter Mean Min Max SD CV% N

ulgobac Control % survival 100.00 100.00 100.00 0.00 0.00 4125 100.00 100.00 100.00 0.00 0.00 4250 100.00 100.00 100.00 0.00 0.00 4500 85.00 80.00 100.00 10.00 3.72 4

1000 0.00 0.00 0.00 0.00 42000 0.00 0.00 0.00 0.00 4

ulgobac Control Temp C 18.00 18.00 18.00 0.00 0.00 1125 18.00 18.00 18.00 0.00 0.00 1250 18.00 18.00 18.00 0.00 0.00 1500 18.00 18.00 18.00 0.00 0.00 1

1000 18.00 18.00 18.00 0.00 0.00 12000 18.00 18.00 18.00 0.00 0.00 1

ulgobac Control pH 7.70 7.70 7.70 0.00 0.00 1125 0.00 0.00 0.00 0.00 0250 0.00 0.00 0.00 0.00 0500 0.00 0.00 0.00 0.00 0

1000 0.00 0.00 0.00 0.00 02000 0.00 0.00 0.00 0.00 0

ulgobac Control Cond uS/cm 56.00 56.00 56.00 0.00 0.00 1125 0.00 0.00 0.00 0.00 0250 0.00 0.00 0.00 0.00 0500 0.00 0.00 0.00 0.00 0

1000 0.00 0.00 0.00 0.00 02000 0.00 0.00 0.00 0.00 0

ulgobac Control DO %sat 91.60 91.60 91.60 0.00 0.00 1125 0.00 0.00 0.00 0.00 0250 0.00 0.00 0.00 0.00 0500 0.00 0.00 0.00 0.00 0

1000 0.00 0.00 0.00 0.00 02000 0.00 0.00 0.00 0.00 0


Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 30/03/2009 19:00 Test ID: PR427/3 Sample ID: JEDS SPRINEnd Date: 1/04/2009 19:00 Lab ID: 3194 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Diluted with Bulgobac water

Conc-% 1 2 3 4ulgobac Control 1.0000 1.0000 1.0000 1.0000ond2670-control 0.0000 0.0000 0.0000 0.0000

6.25 1.0000 1.0000 1.0000 1.000012.5 1.0000 1.0000 1.0000 1.0000

25 1.0000 1.0000 1.0000 1.000050 1.0000 1.0000 1.0000 1.0000

100 0.0000 0.0000 0.0000 0.0000

Transform: Arcsin Square Root Rank 1-Tailed IsotoConc-% Mean N-Mean Mean Min Max CV% N Sum Critical Mean

ulgobac Control 1.0000 1.3453 1.3453 1.3453 0.000 4 1.0000ond2670-control 0.0000 0.2255 0.2255 0.2255 0.000 4

6.25 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 1.000012.5 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 1.0000

25 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 1.000050 1.0000 1.3453 1.3453 1.3453 0.000 4 18.00 10.00 1.0000

100 0.0000 0.2255 0.2255 0.2255 0.000 4 0.0000

Auxiliary Tests Statistic Critical SkewShapiro-Wilk's Test indicates normal distribution (p > 0.01) 1 0.868Equality of variance cannot be confirmedThe control means are significantly different (p = 3.42E-59) 1.12E+10 2.446912Hypothesis Test (1-tail, 0.05) NOEC LOEC ChV TUSteel's Many-One Rank Test 50 100 70.71068 2

Log-Logit Interpolation (200 Resamples)Point % SD 95% CL(Exp) SkewIC05 63.344 0.000 63.344 63.344 1.0076IC10 65.153 0.000 65.153 65.153 1.0076IC15 66.298 0.000 66.298 66.298 1.0076IC20 67.173 0.000 67.173 67.173 -1.0076IC25 67.904 0.000 67.904 67.904 -1.0076IC40 69.699 0.000 69.699 69.699 -1.0076IC50 70.770 0.000 70.770 70.770 -1.0076

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Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 30/03/2009 19:00 Test ID: PR427/3 Sample ID: JEDS SPRINEnd Date: 1/04/2009 19:00 Lab ID: 3194 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Diluted with Bulgobac water

Auxiliary Data SummaryConc-% Parameter Mean Min Max SD CV% N

ulgobac Control % survival 100.00 100.00 100.00 0.00 0.00 4ond2670-control 0.00 0.00 0.00 0.00 4

6.25 100.00 100.00 100.00 0.00 0.00 412.5 100.00 100.00 100.00 0.00 0.00 4

25 100.00 100.00 100.00 0.00 0.00 450 100.00 100.00 100.00 0.00 0.00 4

100 0.00 0.00 0.00 0.00 4ulgobac Control Temp C 18.00 18.00 18.00 0.00 0.00 1ond2670-control 18.00 18.00 18.00 0.00 0.00 1

6.25 18.00 18.00 18.00 0.00 0.00 112.5 18.00 18.00 18.00 0.00 0.00 1

25 18.00 18.00 18.00 0.00 0.00 150 18.00 18.00 18.00 0.00 0.00 1

100 18.00 18.00 18.00 0.00 0.00 1ulgobac Control pH 7.90 7.90 7.90 0.00 0.00 1ond2670-control 7.60 7.60 7.60 0.00 0.00 1

6.25 7.80 7.80 7.80 0.00 0.00 112.5 7.60 7.60 7.60 0.00 0.00 1

25 7.30 7.30 7.30 0.00 0.00 150 7.40 7.40 7.40 0.00 0.00 1

100 7.40 7.40 7.40 0.00 0.00 1ulgobac Control Cond uS/cm 59.00 59.00 59.00 0.00 0.00 1ond2670-control 2670.00 2670.00 2670.00 0.00 0.00 1

6.25 353.00 353.00 353.00 0.00 0.00 112.5 547.00 547.00 547.00 0.00 0.00 1

25 862.00 862.00 862.00 0.00 0.00 150 1567.00 1567.00 1567.00 0.00 0.00 1

100 2670.00 2670.00 2670.00 0.00 0.00 1ulgobac Control DO %sat 93.50 93.50 93.50 0.00 0.00 1ond2670-control 92.60 92.60 92.60 0.00 0.00 1

6.25 95.80 95.80 95.80 0.00 0.00 112.5 91.90 91.90 91.90 0.00 0.00 1

25 95.20 95.20 95.20 0.00 0.00 150 96.30 96.30 96.30 0.00 0.00 1

100 95.10 95.10 95.10 0.00 0.00 1


Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 1/04/2009 19:00 Test ID: PR427/2 Sample ID: Zinc in Bulgobac waterEnd Date: 3/04/2009 19:00 Lab ID: 3193 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Zinc chloride spiked into Bulgobac water- measured concentrations

Conc-mg/L 1 2 3 4ulgobac Control 1.0000 1.0000 1.0000 1.0000

1.2 0.4000 0.6000 0.2000 0.20002.4 0.0000 0.0000 0.0000 0.00004.9 0.0000 0.0000 0.0000 0.00009.8 0.0000 0.0000 0.0000 0.000019 0.0000 0.0000 0.0000 0.0000

Transform: Arcsin Square Root 1-Tailed IsotoConc-mg/L Mean N-Mean Mean Min Max CV% N t-Stat Critical MSD Mean

ulgobac Control 1.0000 1.0000 1.3453 1.3453 1.3453 0.000 4 1.0000*1.2 0.3500 0.3500 0.6245 0.4636 0.8861 32.527 4 7.096 2.353 0.2390 0.35002.4 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 0.00004.9 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 0.00009.8 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 0.000019 0.0000 0.0000 0.2255 0.2255 0.2255 0.000 4 0.0000

Auxiliary Tests Statistic Critical SkewShapiro-Wilk's Test indicates normal distribution (p > 0.01) 0.856379 0.749 0.792403Equality of variance cannot be confirmedHypothesis Test (1-tail, 0.05) MSDu MSDp MSB MSE F-ProbHeteroscedastic t Test indicates significant differences 0.150717 0.158649 1.03899 0.020633 3.9E-04

Log-Logit Interpolation (200 Resamples)Point mg/L SD 95% CL(Exp) SkewIC05* 0.6530 0.0305 0.5585 0.7439 -0.0806IC10* 0.7551 0.0363 0.6431 0.8634 -0.0758IC15* 0.8215 0.0401 0.6977 0.9414 -0.0728IC20* 0.8731 0.0432 0.7400 1.0022 -0.0706IC25* 0.9168 0.0458 0.7757 1.0539 -0.0688IC40* 1.0264 0.0525 0.8648 1.1841 -0.0644IC50* 1.0934 0.0566 0.9190 1.2639 -0.0860* indicates IC estimate less than the lowest concentration

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Ceriodaphnia Survival and Reproduction Test-48 Hr SurvivalStart Date: 1/04/2009 19:00 Test ID: PR427/2 Sample ID: Zinc in Bulgobac waterEnd Date: 3/04/2009 19:00 Lab ID: 3193 Sample Type: AMB1-Ambient waterSample Date: Protocol: 101-ESA SOP101 Test Species: CA-Ceriodaphnia spinataComments: Zinc chloride spiked into Bulgobac water- measured concentrations

Auxiliary Data SummaryConc-mg/L Parameter Mean Min Max SD CV% N

ulgobac Control % survival 100.00 100.00 100.00 0.00 0.00 41.2 35.00 20.00 60.00 19.15 12.50 42.4 0.00 0.00 0.00 0.00 44.9 0.00 0.00 0.00 0.00 49.8 0.00 0.00 0.00 0.00 419 0.00 0.00 0.00 0.00 4

ulgobac Control Temp C 18.00 18.00 18.00 0.00 0.00 11.2 18.00 18.00 18.00 0.00 0.00 12.4 18.00 18.00 18.00 0.00 0.00 14.9 18.00 18.00 18.00 0.00 0.00 19.8 18.00 18.00 18.00 0.00 0.00 119 18.00 18.00 18.00 0.00 0.00 1

ulgobac Control pH 7.80 7.80 7.80 0.00 0.00 11.2 7.80 7.80 7.80 0.00 0.00 12.4 7.80 7.80 7.80 0.00 0.00 14.9 7.80 7.80 7.80 0.00 0.00 19.8 7.80 7.80 7.80 0.00 0.00 119 7.80 7.80 7.80 0.00 0.00 1

ulgobac Control Cond uS/cm 59.00 59.00 59.00 0.00 0.00 11.2 60.00 60.00 60.00 0.00 0.00 12.4 61.00 61.00 61.00 0.00 0.00 14.9 59.00 59.00 59.00 0.00 0.00 19.8 59.00 59.00 59.00 0.00 0.00 119 56.00 56.00 56.00 0.00 0.00 1

ulgobac Control DO %sat 91.40 91.40 91.40 0.00 0.00 11.2 92.60 92.60 92.60 0.00 0.00 12.4 95.10 95.10 95.10 0.00 0.00 14.9 94.30 94.30 94.30 0.00 0.00 19.8 92.70 92.70 92.70 0.00 0.00 119 95.10 95.10 95.10 0.00 0.00 1


Report of Chemical Analyses

REPORT OF ANALYSISREPORT OF ANALYSIS

Laboratory Reference:Laboratory Reference: A09/1074-AA09/1074-A

Order No:Order No:Client:Client: Ecotox Services Australasia Pty LtdEcotox Services Australasia Pty LtdUnit 27/2 Chaplin DriveUnit 27/2 Chaplin Drive Project:Project: Water Analysis Proj No. PR0427Water Analysis Proj No. PR0427Lane Cove NSW 2066Lane Cove NSW 2066 Sample Type:Sample Type: WaterWater

No. of Samples:No. of Samples: 77Contact:Contact: Rick KrassoiRick Krassoi Date Received:Date Received: 3/04/20093/04/2009

Date Completed:Date Completed: 7/04/20097/04/2009

Laboratory Contact Details:Laboratory Contact Details:

Client Services Manager:Client Services Manager: Attila TottszerAttila TottszerTechnical Enquiries:Technical Enquiries: Ian EckhardIan EckhardTelephone:Telephone: +61 2 9888 9077+61 2 9888 9077Fax:Fax: +61 2 9888 9577+61 2 9888 9577Email:Email: [email protected]@advancedanalytical.com.au

Attached Results Approved By:Attached Results Approved By:

Comments:Comments:All samples tested as submitted by client. All attached results have been checked and approved for release.All samples tested as submitted by client. All attached results have been checked and approved for release.This is the Final Report and supersedes any reports previously issued with this batch number.This is the Final Report and supersedes any reports previously issued with this batch number.This document is issued in accordance with NATA's accreditation requirements. Accredited for complianceThis document is issued in accordance with NATA's accreditation requirements. Accredited for compliancewith ISO/IEC 17025. This document shall not be reproduced, except in full.with ISO/IEC 17025. This document shall not be reproduced, except in full.

Page 1 of 4Page 1 of 48 April 20098 April 2009Issue Date:Issue Date:Advanced Analytical Australia Pty ltdAdvanced Analytical Australia Pty ltd Ph: + 61 2 9888 9077Ph: + 61 2 9888 9077ABN 20 105 644 979ABN 20 105 644 979 Fax: + 61 2 9888 9577Fax: + 61 2 9888 957711 Julius Avenue,11 Julius Avenue, [email protected]@advancedanalytical.com.auNorth Ryde NSW 2113 AustraliaNorth Ryde NSW 2113 Australia www.advancedanalytical.com.auwww.advancedanalytical.com.au

A09/1074-AA09/1074-A Project:Project: Water Analysis Proj No. PR0427Water Analysis Proj No. PR0427Batch Number:Batch Number:

Laboratory Reference: - - /1 /2 /3 /4Client Reference: - - Zinc 125µg/L Zinc 250µg/L Zinc 500µg/L Zinc

1000µg/LDate Sampled: - - 03/04/2009 03/04/2009 03/04/2009 03/04/2009Analysis Description Method Units

Zinc - Dissolved 04-003 mg/L 1.2 2.4 4.9 9.8

Laboratory Reference: - - /5 /6 /7Client Reference: - - Zinc

2000µg/LJeds Spring

Water(treated)

Bulgobac

Date Sampled: - - 03/04/2009 03/04/2009 03/04/2009Analysis Description Method Units

Aluminium - Dissolved 04-003 mg/L [NA] <0.03 0.14Arsenic - Dissolved 04-003 mg/L [NA] <0.020 <0.020Cobalt - Dissolved 04-003 mg/L [NA] 0.13 <0.004Copper - Dissolved 04-003 mg/L [NA] <0.002 <0.002Iron - Dissolved 04-003 mg/L [NA] <0.020 0.15Manganese - Dissolved 04-003 mg/L [NA] 10 0.002Nickel - Dissolved 04-003 mg/L [NA] 0.33 <0.003Lead - Dissolved 04-003 mg/L [NA] <0.006 <0.006Zinc - Dissolved 04-003 mg/L 19 2.3 0.009

Method Method Description

04-003 Metals by ICP-OES, mg/L

Result CommentsResult Comments[<][<] Less thanLess than[INS][INS] Insufficient sample for this testInsufficient sample for this test[NA][NA] Test not requiredTest not requiredThis report supersedes Interim Report A09-1074-A-[R00].pdf. This report supersedes Interim Report A09-1074-A-[R00].pdf.



QUALITY ASSURANCE REPORTQUALITY ASSURANCE REPORT

TEST UNITS Blank Duplicate Sm# Duplicate Results Spike Sm# SpikeResults

Aluminium - Dissolved mg/L <0.03 A09/1074-A-6 <0.03 || <0.03 A09/1074-A-6 86%Arsenic - Dissolved mg/L <0.020 A09/1074-A-6 <0.020 || <0.020 A09/1074-A-6 90%Cobalt - Dissolved mg/L <0.004 A09/1074-A-6 0.13 || 0.13 || RPD: 0 A09/1074-A-6 84%Copper - Dissolved mg/L <0.002 A09/1074-A-6 <0.002 || <0.002 A09/1074-A-6 87%Iron - Dissolved mg/L <0.020 A09/1074-A-6 <0.020 || <0.020 A09/1074-A-6 80%Manganese - Dissolved mg/L <0.002 A09/1074-A-6 10 || 11 || RPD: 10 A09/1074-A-6 100%Nickel - Dissolved mg/L <0.003 A09/1074-A-6 0.33 || 0.34 || RPD: 3 A09/1074-A-6 85%Lead - Dissolved mg/L <0.006 A09/1074-A-6 <0.006 || <0.006 A09/1074-A-6 84%Zinc - Dissolved mg/L <0.003 A09/1074-A-6 2.3 || 2.4 || RPD: 4 A09/1074-A-6 89%



Comments:Comments:RPDRPD = Relative Percent Deviation= Relative Percent Deviation[NT][NT] = Not Tested= Not Tested[N/A][N/A] = Not Applicable= Not Applicable'#''#' = Spike recovery data could not be calculated due to high levels of contaminants= Spike recovery data could not be calculated due to high levels of contaminantsAcceptable replicate reproducibility limit or RPD:Acceptable replicate reproducibility limit or RPD: Results < 10 times LOR: no limits.Results < 10 times LOR: no limits.

Results >10 times LOR: 0% - 50%.Results >10 times LOR: 0% - 50%.Acceptable matrix spike & LCS recovery limits:Acceptable matrix spike & LCS recovery limits: Trace elements 70-130%Trace elements 70-130%

Organic analyses 50-150%Organic analyses 50-150%SVOC & speciated phenols 10-140%SVOC & speciated phenols 10-140%Surrogates 10-140%Surrogates 10-140%

When levels outside these limits are obtained, an investigation into the cause of the deviationWhen levels outside these limits are obtained, an investigation into the cause of the deviationis performed before the batch is accepted or rejected, and results are released.is performed before the batch is accepted or rejected, and results are released.


REPORT OF ANALYSISREPORT OF ANALYSIS

Laboratory Reference:Laboratory Reference: A09/1074-BA09/1074-B

Order No:Order No:Client:Client: Ecotox Services Australasia Pty LtdEcotox Services Australasia Pty LtdUnit 27/2 Chaplin DriveUnit 27/2 Chaplin Drive Project:Project: Water Analysis Proj No. PR0427Water Analysis Proj No. PR0427Lane Cove NSW 2066Lane Cove NSW 2066 Sample Type:Sample Type: WaterWater

No. of Samples:No. of Samples: 77Contact:Contact: Rick KrassoiRick Krassoi Date Received:Date Received: 3/04/20093/04/2009

Date Completed:Date Completed:

Laboratory Contact Details:Laboratory Contact Details:

Client Services Manager:Client Services Manager: Attila TottszerAttila TottszerTechnical Enquiries:Technical Enquiries: Ian EckhardIan EckhardTelephone:Telephone: +61 2 9888 9077+61 2 9888 9077Fax:Fax: +61 2 9888 9577+61 2 9888 9577Email:Email: [email protected]@advancedanalytical.com.au

Attached Results Approved By:Attached Results Approved By:

Comments:Comments:All samples tested as submitted by client. All attached results have been checked and approved for release.All samples tested as submitted by client. All attached results have been checked and approved for release.This is the Final Report and supersedes any reports previously issued with this batch number.This is the Final Report and supersedes any reports previously issued with this batch number.This document is issued in accordance with NATA's accreditation requirements. Accredited for complianceThis document is issued in accordance with NATA's accreditation requirements. Accredited for compliancewith ISO/IEC 17025. This document shall not be reproduced, except in full.with ISO/IEC 17025. This document shall not be reproduced, except in full.

Page 1 of 4Page 1 of 47 April 2009 {Interim Report Date}7 April 2009 {Interim Report Date}Issue Date:Issue Date:Advanced Analytical Australia Pty ltdAdvanced Analytical Australia Pty ltd Ph: + 61 2 9888 9077Ph: + 61 2 9888 9077ABN 20 105 644 979ABN 20 105 644 979 Fax: + 61 2 9888 9577Fax: + 61 2 9888 957711 Julius Avenue,11 Julius Avenue, [email protected]@advancedanalytical.com.auNorth Ryde NSW 2113 AustraliaNorth Ryde NSW 2113 Australia www.advancedanalytical.com.auwww.advancedanalytical.com.au

A09/1074-BA09/1074-B Project:Project: Water Analysis Proj No. PR0427Water Analysis Proj No. PR0427Batch Number:Batch Number:

Laboratory Reference: - - /6 /7Client Reference: - - Jeds Spring

Water(treated)

Bulgobac

Date Sampled: - - 03/04/2009 03/04/2009Analysis Description Method Units

Aluminium - Total 04-003 mg/L <0.03 0.19Arsenic - Total 04-003 mg/L <0.020 <0.020Cobalt - Total 04-003 mg/L 0.15 <0.004Copper - Total 04-003 mg/L <0.002 <0.002Iron - Total 04-003 mg/L 0.02 0.22Manganese - Total 04-003 mg/L 12 0.003Nickel - Total 04-003 mg/L 0.38 <0.003Lead - Total 04-003 mg/L <0.006 <0.006Zinc - Total 04-003 mg/L 2.6 0.014Calcium - Total SUB mg/LMagnesium - Total SUB mg/LSodium - Total SUB mg/LPotassium - Total SUB mg/LDissolved Organic Carbon SUB mg/LTotal Alkalinity SUB mg/LHardness SUB mg/LSulphate SUB mg/L

Method Method Description

04-003 Metals by ICP-OES, mg/L SUB Subcontracted Analyses

Result CommentsResult Comments[<][<] Less thanLess than[INS][INS] Insufficient sample for this testInsufficient sample for this test[NA][NA] Test not requiredTest not required



QUALITY ASSURANCE REPORTQUALITY ASSURANCE REPORT

TEST UNITS Blank Duplicate Sm# Duplicate Results Spike Sm# SpikeResults

Aluminium - Total mg/L <0.03 A09/1074-B-6 <0.03 || <0.03 A09/1074-B-6 86%Arsenic - Total mg/L <0.020 A09/1074-B-6 <0.020 || <0.020 A09/1074-B-6 90%Cobalt - Total mg/L <0.004 A09/1074-B-6 0.15 || 0.15 || RPD: 0 A09/1074-B-6 84%Copper - Total mg/L <0.002 A09/1074-B-6 <0.002 || <0.002 A09/1074-B-6 89%Iron - Total mg/L <0.02 A09/1074-B-6 0.02 || <0.02 A09/1074-B-6 87%Manganese - Total mg/L <0.002 A09/1074-B-6 12 || 12 || RPD: 0 A09/1074-B-6 97%Nickel - Total mg/L <0.003 A09/1074-B-6 0.38 || 0.38 || RPD: 0 A09/1074-B-6 85%Lead - Total mg/L <0.006 A09/1074-B-6 <0.006 || <0.006 A09/1074-B-6 83%Zinc - Total mg/L <0.003 A09/1074-B-6 2.6 || 2.5 || RPD: 4 A09/1074-B-6 88%

TEST UNITS Blank

Sulphate mg/L

Page 3 of 4Page 3 of 47 April 2009 {Interim Report Date}7 April 2009 {Interim Report Date}Issue Date:Issue Date:

Advanced Analytical Australia Pty ltdAdvanced Analytical Australia Pty ltd Ph: + 61 2 9888 9077Ph: + 61 2 9888 9077ABN 20 105 644 979ABN 20 105 644 979 Fax: + 61 2 9888 9577Fax: + 61 2 9888 957711 Julius Avenue,11 Julius Avenue, [email protected]@advancedanalytical.com.auNorth Ryde NSW 2113 AustraliaNorth Ryde NSW 2113 Australia www.advancedanalytical.com.auwww.advancedanalytical.com.au


Comments:Comments:RPDRPD = Relative Percent Deviation= Relative Percent Deviation[NT][NT] = Not Tested= Not Tested[N/A][N/A] = Not Applicable= Not Applicable'#''#' = Spike recovery data could not be calculated due to high levels of contaminants= Spike recovery data could not be calculated due to high levels of contaminantsAcceptable replicate reproducibility limit or RPD:Acceptable replicate reproducibility limit or RPD: Results < 10 times LOR: no limits.Results < 10 times LOR: no limits.

Results >10 times LOR: 0% - 50%.Results >10 times LOR: 0% - 50%.Acceptable matrix spike & LCS recovery limits:Acceptable matrix spike & LCS recovery limits: Trace elements 70-130%Trace elements 70-130%

Organic analyses 50-150%Organic analyses 50-150%SVOC & speciated phenols 10-140%SVOC & speciated phenols 10-140%Surrogates 10-140%Surrogates 10-140%

When levels outside these limits are obtained, an investigation into the cause of the deviationWhen levels outside these limits are obtained, an investigation into the cause of the deviationis performed before the batch is accepted or rejected, and results are released.is performed before the batch is accepted or rejected, and results are released.



Appendix I – Kevin Rosengren & Associates Pty Ltd Fossey Zinc-Lead Deposit. Geotechnical Review 2009.

Kevin Rosengren & Associates Pty. Ltd.CONSULTING MINING ENGINEERS

Principal: ACN 010 348 571

K.J. Rosengren, BCE, BME, MEngSc, PhD, FAusIMM, FIMM, MMICA ABN 17 727 665 740 Registered Professional Engineer, Queensland.

July18, 200928039

Bass Metals LimitedPO Box 1330

WEST PERTH WA 6872

Attention: Mr Tim Akerman Project Manager

Dear Sirs,

FOSSEY ZINC-LEAD DEPOSIT

GEOTECHNICAL REVIEW

This report presents a review of specific geological aspects of the Fossey zinc-lead deposit in

Tasmania. The review is based on information provided by Bass Metals Limited.

1. BACKGROUND INFORMATION

The Fossey deposit is effectively the southern extension of the larger Hellyer deposit. However,

it is not continuous with the Hellyer deposit and is displaced to the west by the Easy Street Fault.

The relationship between the two deposits is shown in plan on Fig. 1.

As would be expected, the geology of the deposit is very similar to that of the Hellyer deposit. (Ref.

1). The deposit is of volcanogenic origin and of Cambrian age and occurs within an alteration zone

(SEZ at Hellyer) within Feldspar Phyric Andesite (FPS at Hellyer). This unit is overlain by the

Hangingwall Dacite Breccia (HVS at Hellyer) and the Hellyer Basalt (PLS at Hellyer). The

distribution of these units is shown on a series of cross-sections in Figs. 3 to 10.

The massive sulphide (BMS) is a flat lying body with a strike length of 160m, a maximum width of

around 40m and a maximum height of around 70m. The BMS zone is overlain by a significant

thickness (up to 50m) of massive barite which contains low grade zinc-lead mineralisation. Small

BMS zones occur within the barite and as discrete bodies outside the main BMS zone.

The published ore resource (Ref. 2) is 830,000t @ 9.1%Zn, 4.6%Pb, 120g/tAg, 2.5g/tAu.

P.O. BOX 361, ASHGROVE, QLD. 40605 HARRY STREET, ASHGROVE, QLD. 4060, AUSTRALIA

TEL: (07) 3366 5088, A/H (07) 3300 4302, FAX: (07) 3366 6146

July 18, 2009 -2- 28039

It is proposed that the deposit will be extracted by a method of open stoping with filling, as was used

successfully at the Hellyer mine. The stopes will extract the full ore profile at each section and both

primary and secondary (pillar) stopes will have a strike length of 20m (as at Hellyer). Primary

stopes will be filled with cemented aggregate fill (CAF), introduced directly to the stope voids via

boreholes from surface. Secondary stopes will be filled with uncemented rockfill or may be left

unfilled.

The mine will have an access independent of the Hellyer mine, via a 900m long, 1.8 gradient

decline, collared from the upper part of the Hellyer haul road, at RL540. This decline will reach the

ore zone at RL435 and the main extraction level for the mine will be established at this level. A

subsidiary decline will be developed down to RL415 for the extraction of 12B Pillar, below 12A stope

at the south end (Fig. 2). An incline system will be developed to access drilling levels at RL485,

RL495, RL510, RL515, RL535.

The mine will be ventilated by two vent shafts, plus the decline (intake) as follows:

• North Vent Shaft (exhaust) - vertical, 3.1m diameter

• South Vent Shaft (intake and escapeway) - inclined, 1.5m diameter

The proposal development layout is shown in plan on Fig. 1, in longitudinal projection on Fig. 2 and

on the series of cross-sections in Figs. 3 to 10.

It should be noted that, as at Hellyer, the HEC 220kV transmission line overlies the ore zone, with

pylon 148 located directly above the eastern side of Pillar 14 (Fig.1).

2. GEOTECHNICAL ISSUES

Geotechnical assessments for the proposed main decline, and for the proposed mining, have been

carried out by Coffey Mining Pty Ltd (Refs. 3 and 4). As at Hellyer, ground conditions in and around

the ore zone are generally favourable. The unit which gave the most trouble at Hellyer was the

SEZ, primarily because of its prominent foliation. However, the Footwall Sequence (Alteration

Zone?) at Fossey is classified as good quality in Ref. 4.

The major differences between Fossey and Hellyer are as follows:

(i) At Hellyer, the Jack Fault was located within the ore zone and caused various stability

problems during stoping. At Fossey, the Jack Fault occurs 50m to 130m to the east of the

ore zone (Fig. 1, Figs. 3 to 10) and is not likely to have any influence on stoping. However,

the incline and the 435 level access crosscut will have to pass through the fault (Fig. 1).

Kevin Rosengren & Associates

July 18, 2009 -3- 28039

(ii) The massive barite zone, immediately above the ore zone is much thicker than that at

Hellyer. However, this unit appears to be massive and competent and is not likely to present

any stability problems for stoping. In fact, conditions are likely to be better than those at

Hellyer where most stopes abutted the HVS unit.

(iii) Major transverse faulting, such as the Easy Street Fault, was not present at Hellyer. At

Fossey, stoping is planned to terminate south of the Easy Street Fault (Fig. 2) and this is not

likely to be a significant issue, with current information. However, the incline access

development must penetrate the fault in several locations (Fig. 1) and the North Vent Shaft

must also penetrate the fault (Figs. 1 and 2).

3. CEMENTED FILL

It is planned that the primary stopes will be filled with cemented aggregate fill (CAF). This CAF

must have sufficient strength to support itself while the intermediate pillar is being extracted. If the

pillar void is not filled, the fill walls must have sufficient strength to be stable in the long term.

Cement fill requirements for the Hellyer mine were investigated in detail in 1994 (Ref. 5). The

results of this work were applied successfully at Hellyer and this experience can be transferred

directly to Fossey. Basically, the strength requirement for a vertical wall of cemented fill is

dependent on the height and width of the exposure. For a given wall height, the required strength

of the fill increases as the exposure width increases because of the reduced influence of arching

in the wider exposures.

For a rectangular exposure, the required compressive strength (Q) of the fill is given by (Ref. 5):

Q = ãH/(1+H/2B) (1)

where ã = bulk density of fill

H = height of exposure

B = width of exposure

At Hellyer and at Fossey, the wall exposures were/are not rectangular and equation (1) was

re-stated in terms of exposure height and hydraulic radius (area/perimeter), as follows:

Q = 4 ãRH/(2R+H) (2)

where ã = fill bulk density

H = height of exposure

R = hydraulic radius (=area/perimeter) of exposure


July 18, 2009 -4- 28039

This equation is plotted graphically on Fig. 11, using ã=24kN/m (2.4t/m )and a factor of safety of3 3

1.5 (Ref. 5). The required fill strength varies from around 1MPa for modest exposures to over 3MPa

for large exposures.

The wall exposures for primary stopes S12A, S16, S20 and S24 are shown on Figs. 12 to 15,

including data on:

• area of exposure

• perimeter of exposure

• height of exposure

• hydraulic radius of exposure.

Results of preliminary strength testing of Hellyer CAF were included in Ref. 5. A linear regression

analysis of the test results yielded the following relation for compressive strength of the fill:

UCS = 0.33 + 0.029C2.5

C = cement content of fill

Additional testing was carried out at Hellyer, but we do not have a record of these results. In any

event, it will be essential that a program of testing be carried out on Fossey fill, using the aggregate

and the cement which will be used for manufacture of the fill.

Required fill strength and indicative cement contents for these exposures are summarised as

follows:

Fill Wall Height (m) HR (m) Strength

(MPa)

Cement

Content (%)

S12A (N) 54 7.3 0.8 3.0

S16 (S) 54 9.8 1.1 3.8

S16 (N) 72 10.5 1.2 3.9

S20 (S) 72 9.5 1.0 3.6

S20 (N) 72 7.9 0.9 3.3

S24 (S) 23 3.0 0.4 1.5

S24 (N) 23 5.0 0.5 2.1

It must be stressed that the quoted cement contents are indicative only, based on Hellyer

preliminary data. Specific testing of Fossey fill samples is essential. For feasibility purposes, it is

suggested that the following cement contents be assumed:


July 18, 2009 -5- 28039

• Pillar stopes to be filled 4% cement

• Pillar stopes to be left open 5% cement.

The required strength results are superimposed on Fig. 10. By comparison, the large exposures

at Hellyer had heights of 100-150m and hydraulic radii of around 20m, requiring fill strength of 2.0-

2.5MPa and cement contents of around 6%.

4. CAVING AND SUBSIDENCE

The north end of the Hellyer deposit was extracted by methods of open stoping with pillar mass

blasting and by sublevel caving, which caused fairly extensive surface subsidence. This issue was

studied in some detail because the surface subsidence was immediately north of transmission pylon

146 and this pylon had to be re-levelled on at least one occasion.

A separate issue was the long term stability of unfilled open stope voids and a detailed study of this

issue was also undertaken at the time of mine closure (Ref. 6). At that time, it was planned to leave

a number of the final voids unfilled, primarily as underground disposal sites for retreated tailings.

In the event, this did not occur and the main adit was plugged. The Hellyer mine workings are now

flooded.

In relation to the collapse of underground voids and caving through to surface, there are two basic

mechanisms, as follows:

• plug caving

• chimney caving

In plug caving, the material above the void unravels and caves towards surface, with area of the

cave approximating the plan area of the void. Block caving is an artificially induced type of plug

caving.

In chimney caving, the area of caving is much less than the plan area of the void. In practice,

chimney caving can only occur if there is a zone of weakness, for example, a fault zone, intersecting

or close to the void. Chimney caving was a real possibility at Hellyer because most of the stopes

had a wall along the Jack Fault. However, this situation does not apply at Fossey and the risk for

chimney caving to occur at Fossey is extremely small.

Even if plug caving does initiate, caving will not advance through to surface unless there is

adequate total void to accept the caved material. If this void is not available, the caving will choke

itself off and will not break through to surface.


July 18, 2009 -6- 28039

For plug caving to just break through to surface, the following volume balance must be satisfied.

Vv+Vp = Vp(1+B) (3)

where Vv = volume of void

Vp = in-situ volume of pillar above void

B = bulking factor

Rearranging, equation (3) gives:

B = [(Vv + Vp)/Vp] - 1 (4)

The value of B obtained from this analysis is interpreted as follows:

B Effect on Surface

<0.15 no influence - will choke off before reaching surface

0.15-0.20 low possibility of subsidence - will probably choke off before reaching surface

>0.20 high possibility if subsidence - will not choke off before reaching surface.

It should be noted that plug caving has already occurred at Hellyer, in the form of 28P pillar at the

south end of the workings (Fig. 1, Plate 1). Analysis of the 28B/30P void yielded a value of B = 0.24

and the void was recognised as having a high risk of plug caving (Ref. 6). This risk was increased

by the small distance of the void beneath the base of weathering and the fact that it was straddled

by two limbs of the Jack Fault.

It should also be noted that the 50P void, which is a large open void directly beneath the southern

access road, yielded a value of B = 0.31. The east wall of this stope abuts the Jack Fault and

unravelling up the fault had occurred even before the mine closure. This void therefore has a

significant risk of plug caving to surface, and the southern access road had been closed over the

stope void. If access through this area needs to be re-opened, it will be necessary to either partially

fill the void, or establish a deviation of the road, which does not traverse the void (Ref. 7).

It is considered that the risk of plug caving over the Fossey stopes and pillars is small because the

rock above the orebody, including the massive barite, is generally competent. Since the primary

stope voids will be open for only a short time before they are filled, they are extremely unlikely

candidates for plug caving. If the pillar voids are not filled, there is a small risk that plug caving

could occur over an extended period of time.

Should plug caving develop over any of the pillar voids, a volume balance analysis yielded the

following results:


July 18, 2009 -7- 28039

Pillar Vv(m ) Vp(m ) B Comment3 3

P14 28,000 215,000 0.13 cannot reach surface

P18 39,000 170,000 0.23 can reach surface

P22A 5,500 98,000 0.06 cannot reach surface

P22B 12,400 88,000 0.14 cannot reach surface

P22A/B(a) 17,900 186,000 0.10 cannot reach surface

P22A/B(b) 17,900 88,000 0.20 may reach surface

P26 6,300 72,000 0.09 cannot reach surface

These results show that, with the possible exception of Pillar 18, and possibly the combined

P22A/22B, with caving above P22B only, the risk of surface disturbance above unfilled pillar stopes

will be small. This risk could be reduced further by partially filling the P18 and P22B voids.

The minimum volumes of fill which need to be placed in P18 and P22A/22B stopes to prevent

breakthrough to surface (B = 0.15) are as follows:

• P18 stope 13,500m3

• P22A/22B stope 5,000m3

In practice, volumes at least 50% greater than those quoted above would be placed, to ensure that

breakthrough to surface did not occur.

Even though the analysis shows that subsidence cannot occur above P14 Pillar, it is highly

recommended that this void be filled to give absolute security to Pylon 148 which is located directly

above the pillar, on the eastern side (Fig. 1).

5. INTERACTION WITH HELLYER

As shown on Fig. 1, the proposed Fossey incline development will be located within 38m of the

Hellyer South Incline at around RL525. The Hellyer workings are flooded and the constant standing

water level (around RL680) in the 28B sinkhole (Plate 1), which must be fully connected to the

workings, suggests that this is the standing water level in the mine workings. This represents a

water head of 155m above the Fossey development.

It is possible that the Easy Street fault forms an impermeable boundary between Hellyer and

Fossey. However, the proposed development penetrates the fault in several locations (Fig. 1) and

any barrier effect of the fault will be negated.


July 18, 2009 -8- 28039

Caution will therefore be required in developing close to the Hellyer workings, unless the water level

in the workings is lowered beforehand. Probe drilling should be carried out to check whether any

water sources are present within 20m of the development. These probe holes must be drilled

through collar valves, to control any unexpected water inflow, and the holes should be grouted on

completion.

6. CLOSURE

We trust that this report is adequate for your immediate requirements. Please contact us should

you require any further information or clarification.

Yours faithfully

KEVIN ROSENGREN & ASSOCIATES PTY LTD

per: K J ROSENGREN


July 18, 2009 -9- 28039

REFERENCES

1. McARTHUR, G.J.DRONSEIKA, E.V.

Que River and Hellyer Zinc-Lead-Silver Deposits,Geology of the Mineral Deposits of Australia and NewZealand (Ed F.E. Hughes), AusIMM, 1990, pp1229-1239.

2. BASS METALS LIMITED

March Quarterly Report of Activities And Cashflow,Report to Australian Stock Exchange,April 21, 2009.

3. COFFEY MINING PTY. LTD

Fossey Decline Geotechnical Assessment,Report No. MINEHOBA0260AA (draft)May 19, 2009.

4. COFFEY MINING PTY. LTD

Geotechnical Assessment Fossey Zone,Report No. MINEHOBA00249AA (draft)May 25, 2009.

5. KEVIN ROSENGRENASSOCIATES PTY LTD

Review of Stope Filling and Surface Subsidence,Report No. 94022, to Aberfoyle Limited,November 14, 1994.


Review of Stability of Final Stope Voids,Report No. 99024, to Western Metals Resources Limited,April 17, 2000.


Hellyer Mine Site, Southern Access Road,Report No. 280122, to Intec LimitedAugust 6, 2008.


Plate1:SINKHOLE

DEVELOPEDABOVE

28BSTOPE

VOID

(LOOKINGWEST)

JACKFAULT

38m

S12A

P14

P18

P22B

P26

S16

S24

S20

STREET

NORTHVENTSHAFT

SOUTHVENTSHAFT

PYLON148

MAINDECLINE

435/L

TO415/L

485/L

495/L

510/L

515/L

535/L

EASY

FAULT

JACK

HEC220kVTRANSMISSIONLINE

FAULTNOTE: ONLY UPPER

DEVELOPMENT SHOWN

INCLINE

28B

30P

42PUW

42PUE

28BSINKHOLE

Kevin Rosengren & Associates Pty LtdCONSULTING MINING ENGINEERS Job No: 28039 Scale 1:1000 Date: Jul 09

BASS METALS LIMITED

REFERENCE: Information provided byBass Metals Limited

10100N

10200N

10300N

10400N

5500E

5600E

10100N

10200N

10300N

10400N

Fig.1

LOCATION PLAN

5700E

HELLYEROPEN VOID

HELLYERFILLED STOPE

EXISTINGDEVELOPMENT

PROPOSEDDEVELOPMENT

P18

S16 PRIMARYSTOPE

SECONDARYSTOPE

LEGEND

HELLYER

SOUTH

INCLINE

KevinRosengren&AssociatesPtyLtd

CONSULTINGMININGENGINEERS

JobNo:28039

Scale1:1000

Date:Jul09

BASSMETALSLIMITED

REFERENCE:

InformationprovidedbyBassMetalsLimited

600

600

10000N

10200N

400

400

Fig. 2

LONGITUDINAL

PROJECTION

10300N

SOUTH

NORTH

500

10100N

500

S12A

P14

P18

P22B

P26

S16

S24

S20

P12B

NORTHVENTSHAFT(EXHAUST)

SOUTHVEN

TSHAFT(I

NTAKE/ES

CAPE)

MAIN

DECLINE

INCLINE

510/L

535/L

435/L

EASYSTRE

ETFAUL

T

?

S12A

P12B

HELLYER BASALT

JACKFAULT

MASSIVEBARITE

HANGINGWALLVOLCANICLASTIC

SEQUENCE

BOX

FELDSPARPHYRICANDESITE


Fig.3

CROSS-SECTION 10120NKevin Rosengren & Associates Pty Ltd

CONSULTING MINING ENGINEERS Job No: 28039 Scale 1:1000 Date: Jul 09

BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

WEATHERED ZONE

Fig.4

CROSS-SECTION 10140N

?

HELLYER BASALT

JACKFAULT

HANGINGWALLVOLCANICLASTIC

SEQUENCE

BOX

FELDSPARPHYRICANDESITE P14



BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

WEATHERED ZONE

Fig.5


HELLYER BASALT

JACKFAULT

BOX


MASSIVEBARITE

?

HVS

S20


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

WEATHERED ZONE

Fig.6


HVS

HELLYER BASALT

JACKFAULT

BOX


MASSIVEBARITE

?

P18


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700


WEATHERED ZONE


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

Fig.7


EASYSTREETFAULT

HELLYER BASALT

JACKFAULT

BOX


MASSIVEBARITE

?

HVS

S20


WEATHERED ZONE


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

Fig.8

CROSS-SECTION 1022 0N

EASYSTREETFAULT

MASSIVEBARITE

HELLYER BASALT

JACKFAULT


?

BOX

P22A

P22B

WEATHERED ZONE


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

Fig.9


EASYSTREETFAULT

HELLYER BASALT

JACKFAULT


MASSIVEBARITE

BOX

S24

? HVS


WEATHERED ZONE

Fig.10


EASYSTREETFAULT


BASS METALS LIMITED


400

500

600

700

WEST EAST

5500E

5600E

400

500

600

700

HELLYER BASALT

JACKFAULT


MASSIVEBARITE

?

BOX

HVS

P26

WEATHERED ZONE

Kevin Rosengren & Associates Pty LtdCONSULTING MINING ENGINEERS Job No: 28039 Scale NTS Date: Jul 09

BASS METALS LIMITED Fig.11

CAF STABILITY CHARTNON-RECTANGULAR EXPOSURES

B=2H

H=200m

H=150m

H=100m

H=75m

H=50m

H=25m

3.5

3.0

2.5

2.0

1.5

1.0

0.5

00 5 10 20 3015 25

REQUIRED

COMPRESSIVE

STRENGTH

(MPa)

HYDRAULIC RADIUS (m)

B=H/2

LARGEHELLYERSTOPES

STOPE 12A

STOPE 16

STOPE 20

STOPE 24

LEGEND


BASS METALS LIMITED

REFERENCE: Information provided by Bass Metals Limited

500

5550E

450

500

450

WEST EAST

STOPE 12AWALL EXPOSURES

485

435

415

A=1200m2P=165mR=7.3mH=54m

NORTH WALL

Fig.12

A=2200m2

P=210m

R=10.5m

H=72m



JobNo:28039

Scale1:500

Date:Jul09

BASSMETALSLIMITED

REFERENCE:


500

500

5500E

5550E

450

450

5500E

5550E

500

450

500

450

STOPE

16WALLEXPOSURES

WEST

EAST

WEST

EAST Fig. 13

485

435

510 43

5

A=1770m2

P=180m

R=9.8m

H=54m

(a)SOUTH

WALL

(b)NORTH

WALL



JobNo:28039

Scale1:500

Date:Jul09

BASSMETALSLIMITED

REFERENCE:


500

500

5500E

5550E

450

450

Fig. 14

STOPE

20WALLEXPOSURES

5500E

5550E

500

450

500

450

WEST

EAST

WEST

EAST

A=1850m2

P=195m

R=9.5m

H=72m

435

510

435

(a)SOUTH

WALL

(b)NORTH

WALL

510

A=1650m2

P=210m

R=7.9m

H=72m



JobNo:28039

Scale1:500

Date:Jul09

BASSMETALSLIMITED

REFERENCE:


500

500

5500E

5550E

450

450

Fig. 15

STOPE

24WALLEXPOSURES

5500E

500

450

500

450

WEST

EAST

WEST

EAST

435

510

435

(a)SOUTH

WALL

(b)NORTH

WALL

510

A=525m

2

P=105m

R=5.0m

H=23m

500

500

500

500

A=300m

2

P=100m

R=3.0m

H=23m

495


Appendix J – GHD Shale Quarry Tailings Dam Closure Memorandum.

32/14673/47029

16 March 2009

To Bass Metals Pty Ltd

Copy to Terry Burns, Tony Thomas

From Rob Longey Tel 03 6210 0692

Subject Shale Quarry Tailings Dam Closure Job no. 32/14673

1 Background InformationThe old Shale Quarry at Bass Metals, Hellyer operation has previously been used as a tailings storagefacility (TSF) as part of the tailings reclamation and reprocessing project by previous operators Intec-Polymetals Ltd. The capacity was increased by construction of a water-retaining dam around the lowside of the pit, with the intention to inundate tailings stored in the quarry with 1m of water on closure.

Since closure it has been noted that the quarry does not maintain sufficient water cover, resulting inexposure of tailings leading to oxidisation and formation of Acid Mine Drainage (AMD). GHD werepreviously engaged by Intec Ltd to investigate the potential causes for the water loss and to provideclosure options for the shale quarry. The investigation included an assessment of the acid producingcharacteristics of the tailings by means of column leach testing. The column leach testing involvesexposure of the tailings to a wetting and drying cycle to simulating conditions in the quarry. The testingfound the tailings are Potentially Acid Forming (PAF) and result in oxidisation and formation of Acid MineDrainage within a period of as little as 4 weeks of exposure to the cycle. Some options for closure wereput forward to Intec Ltd including increasing the catchment, decreasing permeability of the tailings usingbentonite, full capping of the tailings and partial capping combined with a water cover.

The findings of the initial report identified the permeability of the tailings as a potential issue.Subsequently Intec Ltd handed over the ownership of the site to Bass Metals who effectively took on theresponsibility for the closure of the shale quarry. Following handover of the site ownership, Bass Metalsengaged GHD to further investigate the tailings permeability and the effect of the bentonite slurry on thetailings permeability by means a field-testing. This document details the findings of the field investigationand recommendations on closure options.

2 Scope of WorkThe scope of works requested by Bass Metals is as follows;

� A trial comparing tailings permeability with different applications of bentonite (including no dose).

� Review and modify field monitoring to ensure that adequate data is collected in the coming months.

� Generate a more detailed review of closure options. It would be expected that the data would beused to estimate a range of expected water losses via the tailings and the shale pit walls underdifferent closure options including different bentonite doses.

The outcome of the field investigation following 4 weeks of consistent monitoring of the field permeabilitywas to review the closure options to a +/-30% cost estimate and provide a recommended closure option.

232/14673/47029

3 Field InvestigationA field investigation of the Shale Quarry TSF was undertaken by GHD on the 17th February 2009. Thepurpose of the investigation was to test the insitu tailings permeability and determine the effect onpermeability following the addition of bentonite slurry to the tailings surface. The investigation involvedthe falling head tests on the tailings surface at three locations. Two falling head test apparatus wereused, comprising modified 44-gallon drums and 140mm diameter perspex cylinders. It was thought the44-gallon drums would give the most accurate results as a large area of tailings was utilised in the test.However due to the dense nature of the tailings surface achieving sufficient penetration of the drumsinto the tailings surface to allow a head difference to be placed on the drum proved difficult and thismethod was abandoned. Three smaller 140mm diameter Perspex cylinders were installed in place of thedrums and these achieved sufficient penetration to cater for the head difference in the cylinder.

It was noted that the tailings surface had been recently exposed for a prolonged period, as the surfaceshowed evidence of cracking and shrinkage due to drying (desiccation). This formed a thick, hard crustthat proved difficult during the installation of the piezometers. Figure 1 below shows the tailings surface.

Figure 1 Tailings surface showing evidence of shrinkage and cracking due to drying

Figure 2 shows the Perspex permeameter cylinder set-up.

332/14673/47029

Figure 2 Falling head test installation

Once an appropriate penetration depth into the tailings was achieved (minimum 300mm) the cylinderswere filled with water and an initial water height measurement and time was recorded. The water heightof the cylinders was then recorded at intervals over next 24 hours. Following the recording of this data, abentonite powder was added to the cylinder to determine the affects on the permeability of the tailings.Monitoring after the bentonite addition was continued by Bass Metals operators for a period of 6 daysafter which high winds blew the cylinders over stopping the falling head test. Figure 3 shows the fallinghead test in progress.

432/14673/47029

Figure 3 Permeability Testing Cylinder

4 Data AnalysisThe falling head monitoring was untaken to determine the permeability of tailings and if the addition ofbentonite decreases the permeability of the tailings. The Top Water Level (TWL) and rainfall data for theperiod of the test was also recorded. This was to note the affect of rising or falling water levels in thedam on the test data. The permeability of the tailings was calculated for each cylinder location. Asampling plan attached in Appendix A shows approximate test locations.

A graphical representation of the available monitoring data is shown in Figure 4. This shows a plot of therate of fall in the three test cylinders plotted against the rate of fall in the shale quarry pond water levelover the 8 days of monitoring undertaken.

From this plot the following is observed;

� The rate of change in the shale quarry pond TWL is reasonably constant throughout the monitoringperiod giving confidence in monitored data.

� Prior to the addition of the bentonite the tailings in cylinders 1 & 2 appear to be of similar permeabilitywhile cylinder 3 appears to be more permeable. Cylinder 3 was located near an exposed mound oftailings near a high point. This may have been located on or near the position of the tailings dischargepipe, which results in coarser tailings settling closer to the discharge point and consequently a higherpermeability.

� The rate of change in the shale quarry pond TWL is greater than the rate of change within thecylinders, with the exception of cylinder 3.

532/14673/47029

Shale Quarry TWL & Cylinder Water Levels vs Time

680.200

680.400

680.600

680.800

681.000

681.200

681.400

681.600

0 100000 200000 300000 400000 500000 600000 700000 800000

Cumulative Time (sec)

Wat

er L

evel

(m)

Shale Quarry TWL(m)Water Level In Cylinder 1Water Level In Cylinder 2Water Level In Cylinder 3

BENTONITEADDITION

BENTONITESETTLES

� In 46hrs following the bentonite addition, the test cylinders showed little change in the rate of fall.After 46hrs the cylinders show a gradual decrease in the rate of fall, which appears to tail out, orfurther decrease towards the end of the monitoring.

Figure 4 Field Monitoring Results

Figure 5 shows a plot of permeability versus time for the three test cylinders. The results are effected bythe rate of fall in the pond TWL shown in Figure 4 related to the fall in the cylinders against time.Permeability is calculated using the equation;

k=V/i=VL/A.Δh.Δt, where;

k=coefficient of permeability (m/s) L=length of tailings sample tested (m)

i=hydraulic gradient Δh =change in head (m)

V=volume (m3) Δt=change in time (s)

A=cylinder area (m2)

32/14673/47029

Shale Quarry TWL & Cylinder Water Levels vs Time

0.0E+00

5.0E-07

1.0E-06

1.5E-06

2.0E-06

2.5E-06

3.0E-06

0 100000 200000 300000 400000 500000 600000 700000 800000

Cumulative Time (sec)

Perm

eabi

lity

(m/s

)

Permeability Cylinder 1Permeability Cylinder 2Permeability Cylinder 3

BENTONITEADDITION

BENTONITESETTLING

DOWNWARDPERMEABILITYTREND

Figure 5 Permeability Results on Monitoring Data

Whilst the permeabilities of the cylinders in Figure 5 appear to vary greatly, the range of permeabilitymeasured is 1x10-6 m/s to 1x10-7 m/s, with the exception of a single reading taken on cylinders 1 & 3after 3.5 days of monitoring (320,000 seconds into testing). This small anomaly appears to be an error inthe reading the gauge. The average permeability of the cylinders initially and after the downward trendappears shown on the graph after on day 6 of testing (515,000 seconds) is shown below in Table 1.

732/14673/47029

Table 1 Average Tailings Permeability

Average Permeability k (m/s)Cylinder

Tailings Only

(0-150,000 sec)

Bentonite Settling Period

(150,000-315,000 sec)

Following DownwardTrend

(315,000 –688,000 sec)

1 5.4x10-7 8.0x10-7 2.7x10-7

2 8.8x10-7 6.0x10-8 2.7x10-8

3 4.3x10-7 8.7x10-7 3.5x10-7

From the above table it can be seen that the permeability in each cylinder reduces from the original valueonce the bentonite settles out and begins to seal the tailings surface. The permeability during the settlingperiod varies showing that the time for the bentonite to take effect is approximately 3.5days - 8days.Further monitoring may have shown a greater decrease however this was not possible after the testcylinders were knocked over in high winds after the 8th day.

5 Opinions and Recommendations

5.1 Shale Quarry Investigations

Given the rate of fall inside the cylinders prior to the addition of bentonite was shown to be slower thanthe rate of fall outside the cylinders this leave two scenarios;

� The individual tailings in the test locations were less permeable than the overall body of the tailings,or

� The shale quarry wall is more permeable than the tailings body.

The latter of the two options is considered more likely as the average calculated permeability is typical fortailings.

5.2 Shale Quarry Closure Options

As discussed above it appears the shale quarry wall is more permeable than the tailings, resulting insignificant loss of water. Therefore the preferred closure option is to remove the effect of the shale quarrywalls. This can be done by means of an engineered clay cap placed 3m wide, running from the east sideof the spillway entrance to the west abutment of the dam wall. To do this the quarry water level wouldneed to be dropped and clay placed and compacted on top of the tailings and against the shale quarrywall. To allow for constructability, a nominal 4m wide working platform would be constructed from shalerock to allow for a 20t excavator to place clay around the outer perimeter of the shale quarry. A typicalsection of the clay cap and associated works is included in Appendix B.

Additionally, there are some low points where the tails are more than 1m below the surface of the water,meaning more than the 1m of clay will need to be placed in these areas. It is suggested that forbudgeting purposes allowance be made for up to 2m of clay to be used, however it may be feasible toinstead use tails excavated from high points in the storage.

832/14673/47029

To prevent erosion of the clay cap and to rehabilitate the shale quarry for closure it is suggested anorganic layer of topsoil/peat is spread over the cap, nominally 0.2m thick. This revegetated cap wouldthen perform two functions, firstly keeping water from the permeable shale quarry wall and secondly,reducing the area of tailings to be covered by water, resulting in more water being available to theremaining pond due to the reduced surface area.

The tailings surface is reasonably hard and can be walked on, so it is assumed the tailings have been leftexposed and the surface has crusted and become more dense. This will help in the construction of thecap as it is likely to be able to take traffic once the initial layer of clay has been placed. However, cautionwill be required during construction as underlying softer layers may mobilise under traffic causing ‘bow’waves from the advancing work area.

A further option to enhance the performance of the closure system would be to add bentonite to theshale quarry pond by pumping it in a slurry or dry distribution from a shallow draft boat. It is envisaged a2mm layer as used in the trials may be sufficient however the requirement for this should be assessedonce the cap has been in place during a summer season to determine its performance in worstconditions.

A sketch of the proposed closure of the shale quarry is shown in Appendix B.

5.3 Closure Cost Estimation

A cost estimate to +/-30% for the preferred shale quarry closure plan is shown in Table 2 below;

Table 2 Shale Quarry Cost Estimate

ITEMNo.

DESCRIPTION QUANTITY UNIT RATE AMOUNT

1.01 Site establishment anddisestablishment

1 Item $5,000 $5,000

1.02 Survey & As Constructed Drawings 1 Item $2,000 $2,000

1.03 Produce clay borrow developmentplan

1 Item $250 $250

1.04 Trimming of batter slopes, grading andrevegetation of rock borrow

1 Item $3,000 $3,000

1.05 Supply 2mm thick engineering gradebentonite over shale quarry pond

130 tonne $544.00 $70,720

1.06 Place 2mm thick engineering gradebentonite over shale quarry pond

130 tonne $100.00 $13,000

1.07 Win from borrow, cart, place andcompact Clay fill

13,000 m3 $6 $78,000

1.08 Win from borrow, cart, place andcompact Clay fill (Provisional Sum fortailings low points)

1,950 m3 $6 $11,700

932/14673/47029

ITEMNo.

DESCRIPTION QUANTITY UNIT RATE AMOUNT

1.09 Win, cart, place and compact rockfillworking platform

5,200 m3 $3 $15,600

1.10 Win from stockpile, cart and placetopsoil 0.2m thick to revegetate overclay layer

1,040 m3 $4 $4,160

Sub Total $203,430

Engineering (5%) $10,172

Contingency(20%)

$40,686

TOTAL $254,288

From the above table it can be seen the estimated closure costs of the shale quarry are $254,288 exGST. However, it should be noted that the bentonite may not be necessary and this would reduceoverall closure costs by $84,000 ex GST. The above estimate covers the capital works associated withprevention of acid mine drainage, the effect of the acid mine drainage emanating from the shale on thequarry wall or ongoing environmental monitoring and water analysis testing has not been included.

In order for Bass Metals to determine the effect of the bentonite a further monitoring program should beinitiated following completion of the edge capping.

Regards

Rob LongeyCivil Engineer6210 0687

1032/14673/47029

Appendix A

Test Location Plan

1132/14673/47029

Appendix B

Preferred Closure Option

REVEGETATEDCAP AREA

POND TWL MIN1m COVER

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