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Leonora Operations

Annual Environmental Report

1 September 2016- 31 August 2017

Prepared by: Dan Pintea, Environmental Superintendent Daniel Gibbons, Senior Environmental Advisor Jon Mountford, Environmental Advisor

Authorised by: Kous Kirsten, General Manager Leonora Operations

St Barbara Limited - Leonora Operations: Kane Street, Leonora, WA 6438

Telephone: (08) 9037 2000

Facsimile: (08) 9037 6988

Email: [email protected]

Leonora Operations: Annual Environmental Report 2016-2017 | St Barbara Limited ii

Table of Contents 1.. INTRODUCTION 1

2.. PRESCRIBED PREMISES CATEGORY ACTIVITY SUMMARY 1

3.. PRESCRIBED PREMISES LICENCE L8337/2009/2 REQUIREMENTS 2

3.1 Environmental incidents and failures/malfunctions of pollution control equipment 2

3.2 Environmental Monitoring 8

3.2.1 Lake Raeside – Table 3.2.1 and provision 3.4.2: Monitoring observations 9

3.2.2 Tower Hill – Table 3.3.1: Monitoring observations 10

3.2.3 Gwalia TSF2 – Table 3.4.1: Monitoring observations 14



3.3 Compliance Report 21

3.4 Complaints Summary 22

3.5 Monitoring equipment calibration data 22

3.6 Construction and compliance documentation relating to Gwalia TSF4 24

APPENDIX A - ANNUAL AUDIT COMPLIANCE REPORT

APPENDIX B – MONITORING DATA: TOWER HILL MONITORING RESULTS

APPENDIX C - MONITORING DATA: GWALIA TSF2 MONITORING RESULTS

APPENDIX D - MONITORING DATA: GWALIA TSF3 MONITORING RESULTS

Leonora Operations: Annual Environmental Report 2016-2017 | St Barbara Limited 1

1 Introduction

This AER has been prepared for the Department of Water and Environmental Regulation

(DEWR), to address all annual reporting requirements outlined within Prescribed

Premises Licence L8337/2009/2; the subject of this licence is the Gwalia Mine site

(Figure 1-1). In particular, this report provides details relevant information stipulated in

the licence under section ‘4.2 - Reporting’.

License Condition 4.2.1 states:

“4.2.1. The Licensee shall submit to the CEO an Annual Environmental Report

within 60 calendar days after the end of the annual period. The report shall contain

the information listed in Table 4.2.1 in the format or form specified in that table.”

Table 4.2.1 has been included below as


Table 1-1.

License Conditions 4.2.2 states:

“4.2.2. The Licensee shall ensure that the Annual Environmental Report also

contains:

(a) any relevant process, production or operational data recorded under

condition 3.1.3; and

(b) an assessment of the information contained within the report against

previous monitoring results and License limits.”

The Annual Audit Compliance Report (AACR) required by the Licence under condition

4.1.2 was submitted to the Department of Water and Environment Regulation (DWER)

separately in October 2017, and has been included as Appendix A - Annual Audit

Compliance Report.

Conditions 4.2.3 and 4.2.4 refer to compliance obligations for landform works which were

not constructed within the 2016 – 2017 reporting period.


Table 1-1: Requirements of the Annual Environment Report as described within L8337/2009/2 Table 4.2.1 and their location within this report.

Table 4.2.1: Annual Environmental Report

Condition or

table (if relevant) Parameter

Format or form/location

within AER

- Summary of any failure or malfunction of

any pollution control equipment and any

environmental incidents that have

occurred during the annual period and

any action taken

None Specified/s3.1; pg.2

Table 3.2.1 Volumetric flow, pH TSS, TDS, WAD-CN,

Na, K, Ca, Mg, As, Pb, Ni, Fe, Cd, Cr, Cu,

Hg, Se, Zn, Cl, CO3, HCO3, SO4, and NO3

None Specified/s3.2.1; pg.9




None Specified/s3.2.2;

pg.10, Appendix B –

Monitoring Data: Tower Hill

Monitoring Results




None Specified/s3.2.3;

pg.14, Appendix C -

Monitoring Data: Gwalia

TSF2 Monitoring Results,

s3.2.4; pp.17; Appendix D

3.4.2 Dewatering discharge report for

discharges to Lake Raeside

None Specified/s3.2.1; pp.9

4.1.2 Compliance Compliance Report/s3.3;

pg.22, Appendix A - Annual

Audit Compliance Report

4.1.3 Complaints summary None Specified/s3.4; pg.23


Figure 1-1: Layout of Gwalia mine site, showing location of key infrastructure.


2 Prescribed Premises Category Activity Summary

Prescribed category activities conducted on the premises during the reporting period

were undertaken at levels consistent with capacities detailed in Prescribed Premises

Licence L8337/2009/2. A summary of these prescribed activities and the intensity of

these activities is summarised in Table 2-1.

Table 2-1: Summary of L8337/2009/2 prescribed categories, capacities and activity levels

Licenced Activity Level Period Activity Level

Category

Number Category Description

Category

Production

or Design

Capacity

Premises

Production

or Design

Capacity

Activity Description Activity Level

5 Processing or beneficiation of

metallic or non-metallic ore

< 1,500,000 tonnes per

annum Gold ore processing 827,534 t

6 Mine Dewatering < 2,500,000 tonnes per

annum

Mine workings

dewatering discharge

to Tower Hill

673,327 kL

(688,960

tonnes)

52

Electric power generation:

premises (other than premises

within category 53 or an

emergency or standby power

generating plant on which

electrical power is generated

using a fuel

10 MW or more in aggregate

(using a fuel other than

natural gas)

Power generation:

4x600 kW dual fuel

generators (diesel

and gas) and 7 x

1200 MW gas

generators

12 MW

73 Bulk storage of chemicals

1,000 m3 in aggregate

(contain at least one carbon

to carbon bond)

Fuel and lubricant

hydrocarbons

374 m3 fixed

bulk <500 m3

aggregate

89 Class II putrescible landfill site More than 20 but less than

5 000 tonnes per year Onsite landfill ~1,600 tonnes


3 Prescribed Premises Licence L8337/2009/2 Requirements

3.1 Environmental incidents and failures/malfunctions of pollution control equipment

Table 3-1: Failure of pollution control device and incident reporting requirement for L8337/2009/2 (Table 4.2.1).


Condition or table

(if relevant) Parameter

Format or

form

-

Summary of any failure or malfunction of any pollution

control equipment and any environmental incidents that

have occurred during the annual period and any action

taken

None

Specified

A list of all the environmental incidents and instances of failure/malfunctions of pollution

control equipment for the reporting period at Leonora Operations is presented below in

Table 3-2.


Table 3-2: Summary of Environmental Incidents and failures/malfunctions of pollution control equipment for the 2016 -2017 reporting period.

Date St Barbara Reference

Description Action taken

18/07/2017 107404 Spillage of hydraulic oil on ROM from a loader following a hydraulic leak. The spill was cleaned up using spill fixer. The contaminated material was disposed of in the hydrocarbon contaminated material skip bins.

24/06/2017 106507 A 10 litre diesel spill was found on the concrete pad at the fuel bay. The spill was cleaned up using spill fixer. The contaminated material was disposed of in the hydrocarbon contaminated material skip bins.

3/06/2017 105849 A contractor disposed of drill sump material at the Gwalia landfill.

The material was recovered and relocated to the bioremediation area.

Education sessions were held to ensure contractors and employees are aware of waste management requirements.

22/05/2017 105395 The electrolyte bund in the processing plant area was identified to be degraded and needs maintenance.

The bund was repaired.

16/05/2017 105171 The chemical storage bund at the batching plant was damaged by the IT forks. The lip on the bund was repaired

13/04/2017 103976 Eastern bore fields low salinity water leaked through a broken off air valve along the road access way. As the water is benign, no adverse impact was observed.

The pipeline was repaired.

A three monthly maintenance order to inspect all air vent valves and rise adaptors was implemented.

10/04/2017 103873 Dust was observed at the crusher area. The water pump feeding the dust suppression sprays was identified as faulty. No dust was observed to leave the area adjacent to the crusher.

Raw water was redirected to the dust suppression sprays

The pump was repaired

24/03/2017 103220 External Reportable - During a period of heavy rainfall (180 mm in 2 days), the TSF 3 toe drain bund was overtopped by water from the toe drain and then water from Lake Raeside breached the TSF 3 toe drain bund.

This incident was reported to the DWER on the 26.03.17.

The initial breach was blocked using a loader. Once the Lake Raeside water rose and started flowing into the toe drain, access to the area was flooded and an excavator was used to block the breach through the West embankment of Grants Patch TSF.

Samples were taken from the toe drain and Lake Raeside and results showing WAD Concentrations of 0.058 mg/l in the toe drain area immediately adjacent to the breach and undetectable levels in Lake Raeside downstream of the breach.




23/04/2017 103170

Rain water overtopped the oily water separator tanks causing these tanks to overflow on the ground into a temporarily formed rain water pond. The water in the tanks had low levels of hydrocarbon contamination, but the receiving water body had very low levels, close to the detectable limit, with no impact expected.

An investigation identified multiple infrastructure issues that were addressed:

Eliminate roof rain water collection tank overflow from entering through the oily water tanks overflow causing overtopping (main cause for tank overflowing)

Lift the hydrocarbon contaminated tanks overflow

Perform maintenance and ensure the oily water separator is operational and connected to the correct tanks.

Ensure discharge from the separator is pumped into clean containers

9/03/2017 102578 While unloading a 1000L pod of Masterock SA 160 underground, the IT punctured the container with the tynes causing the chemical to spill.

As the chemical is a cement accelerant, the material was scraped and mixed in with the concrete paste that fills underground stopes.

6/02/2017 101467 Quick Spill – Following a rain event, a temporary bund was overtopping with oily water

All the contaminated material was removed to the bioremediation area.

The bund was emptied of the oily water and the liquid was disposed of at the oily water storage tank to be removed off site.

The temporary bund was stored to avoid water ingress

31/01/2017 101313 Quick Spill – Approximately 20 l of salt bath solution was spilled on the ground next to the storage container

Spill fixer was used to absorb the spill. All the contaminated material was recovered and removed off site.

30/01/2017 101296

During a high intensity rainfall event (15 mm in 30 min, 70 mm in one day and 143 mm in 3 days) part of the sedimentation pond at the paste plant tailings stockpile was washed out and sediments mixed with tailings were mobilized and discharged into the drainage line downstream

Sedimentation pond was repaired and reinforced to withstand similar events

Sediments and tailings were recovered and the drainage line cleaned up.

29/01/2017 101277

During a high intensity rainfall event (15 mm in 30 min, 70 mm in one day and 143 mm in 3 days), sediments were mobilized from the embankments of TSF 3, flowing down the West ramp. The sediments were deposited on the road and the area between TSF 3 and TSF 2 as a thin layer.

Material was recovered and the area cleaned up.

The west ramp was reshaped to ensure any future erosion material is directed in the TSF toe drain.

28/01/2017 101221

Following a high rainfall event rainfall (15 mm in 30 min, 70 mm in one day), the main wash bay oil separator was overtopped by storm water and the evaporation pond associated with the oily water separator overflowed. Water samples taken from the storm water drain showed very low TRH concentrations, close to the detection limit.(0.016 mg/l)

A contractor was engaged to remove sediments deposited in the separator sumps and the separator was re-started

The area was reshaped to ensure water does not flow towards the oil separator and wash bay.




6/01/2017 100367 Oil separator clogged and not working properly allowing oil through to the storage pond.

Equipment was fixed and inspected

A contractor was engaged to remove the hydrocarbons from the evaporation pond.

29/12/2016 100046 Quick Spill - Spillage of ANE within the ANE facility (less than 5 litres) ANE was cleaned up and disposed of in the waste ANE bins.

27/12/2016 100019 Quick Spill- A hydraulic oil hose ruptured on a Heavy vehicle on the ROM pad The spill has been cleaned up and the contaminated material disposed of at the bioremediation area

22/12/2016 99845 Quick Spill - Spillage of ANE emulsion observed at the emulsion facility (less than 5 litres)

ANE was cleaned up and disposed of in the waste ANE bins.

19/12/2016 99779 Quick Spill - Fuel spillage at the fuel farm within the bunded area (<5 L) Spill fixer was used to clean up the spill and it was disposed of in the hydrocarbon contaminated material skip bins

2/12/2016 99138 Quick Spill – A poly pipe split and was spraying saline water next to the processing plant water cart stand pipe on a hard stand area

Pipeline was isolated and repaired.

5/11/2016 98158 Quick Spill - Gwalia ANE storage facility emulsion spillage on the concrete pad Spillage was cleaned up

31/10/2016 98005

During an inspection a saline spill was noticed at the Eastern Bore fields. The spill was confined to the access road and no impact was observed. The cause was not determined as apparently came from a valve that an unidentified person opened.

Investigation into where the water came from and then who opened the valve with no success.

28/10/2016 98004 Quick spill: Hazard - 60 L diesel fuel spill during refueling of an underground truck on the concrete pad at the fuel farm.

The spill has been cleaned up using spill fixer and disposed of in the hydrocarbon contaminated material skip bins.

The truck was repaired

22/10/2016 97572

While transferring cement from the main silo to the working silo the flexible coupling on the working silo (between the silo and the rotary valve) split causing release of the cement from the silo (approx 20t). The rupture occurred at the end of the transfer cycle which resulted in the release of around 85% of the silo capacity. The wind direction at the time was from the east which caused the majority of the cement to fall around the lower control room, car park and towards the western stockpile. As the cement was contained to the paste plant and tailings stockpile premises there was no environmental impact observed on the surrounding areas.

Transfer was stopped and the paste plant was shut down

The supervisor was alerted and

The cement was cleaned up.

Identified an issue with the stock description in the accounting software that lead to the fitting of the wrong seal and rectified the issue.

22/10/2016 97572 Quickspill - Unattended spill found next to the waste oil tank (<5l). Spill fixer was applied, but not enough and not over the whole spill

The spill was cleaned-up and the contaminated material disposed of in the hydrocarbon contaminated material skip bins.




10/10/2016 97153 Quickspill - Unattended spill found at contractor workshop on the concrete pad

The supervisor was contacted and education was provided to the work group regarding hydrocarbon and chemical spill management

The spill was cleaned up using spill fixer and the material was disposed of in the hydrocarbon contaminated material skip bins

10/10/2016 97151 Quickspill - Unattended spill found at the Projects workshop on the concrete pad (<2L)

The supervisor was contacted and education was provided to the work group regarding hydrocarbon and chemical spill management

The spill was cleaned up using spill fixer and the material was disposed of in the hydrocarbon contaminated material skip bins

1/10/2016 96887 Spill left unattended at contractor workshop on the concrete pad. Spill fixer was dispersed over the spill

Discussion was held with the supervisor and the spill has been cleaned up

29/09/2016 96789 During refueling activities of an underground truck, fuel spilled through the trucks breather hose. The operator placed spill fixer on the spill.

The spill was cleaned up and the spill fixer was disposed of in the hydrocarbon contaminated material skip bins

The breather valve on the truck was fixed

29/09/2016 97598 The Carbon Regeneration Kiln was replaced with a different unit without the work being referred to the DWER.

Once the Environmental Superintendent became aware he notified the DWER licensing branch and this was included in the Gwalia Mine Site EP Act License.

A new step was introduced in the technical services department’s project management to include referral for approvals to the Environmental Department

The Environmental department was introduced in the management of Change consultation step and in the Capital expense approval list to ensure they are aware of new projects.

28/09/2016 96982 A small diameter saline pipeline feeding water to the drill sites has ruptured and the saline water spill was retained within the purposely built V drain.

The line was repaired and inspected

27/09/2016 96734 A 2-5 liter fuel spill was found on the concrete pad at the fuel bay. The spill was cleaned up using spill fixer and the contaminated material was disposed of in the hydrocarbon contaminated material skip bins.

24/09/2016 96661

During an inspection at the Eastern Bore field it was observed that Bore 17 breather valve has a small saline water leak with the saline water confined to the bore area.

Maintenance actioned and leak was repaired.




28/08/2016 96767 15 litres of diesel into the concrete driveway at fuel farm during maintenance work

The spill was cleaned up using spill fixer and the contaminated material was disposed of in the hydrocarbon contaminated material skip bins.

The valve that allowed the spill was padlocked

4/09/2016 95879 Quick spill - Hydrocarbon spills at contractor workshop and laydown yard

The spills were cleaned up using spill fixer and the contaminated material was disposed of in the hydrocarbon contaminated material skip bins.

Discussed spill clean-up requirements with the contractor supervisor


3.2 Environmental Monitoring

At the commencement of the 2016-2017 reporting period, Prescribed Premises Licence

L8337/2009/2 as issued on the 9th of February 2014 was inforce; however, on the 7th of

December 2016, an amended version of the licence was issued. Due to the timing of this

licence amendment, environmental monitoring conducted during the first half of the

reporting period was undertaken in accordance with the provisions of the previous version

of the licence, while environmental monitoring conducted during the second half of the

reporting period was undertaken in accordance with the provisions of the 2016 amended

licence.

The Licence stipulates the following environmental monitoring and reporting:

Lake Raeside: Licence Table 3.2.1 and provision 3.4.2 (Table 3-3);

Tower Hill and Harbour Lights: Licence Table 3.3.1 (Table 3-4); and

Gwalia Tailings Storage Facilities 2, 3 and 4: Licence Table 3.4.1 (Table 3-6, Table 3-8 and Table 3-10).

Section 4.2.2 of the licence also requires that the AER includes an assessment of

monitoring results against previous monitoring results and Licence limits; this provision of

the Licence is met through the analyses of results detailed throughout this section of the

report. In the context of the current reporting period, results have also been assessed in

respect to the significant rainfall experienced in the region throughout the previous twelve

months.

The average annual rainfall of the Leonora region is ~236 mm; as compared to the 603.2

mm of rainfall observed during the reporting period (Figure 3-1). Much of this greater than

average rainfall took place during discrete extreme weather events; consequently,

localised flooding, infrastructure damage and pronounced groundwater table responses

occurred during the reporting period.


Figure 3-1: Leonora Rainfall observations September 2012 to September 2017

The monitoring data required to be reported under the Licence, along with an assessment

of these results is presented in the following subsections of this AER.

3.2.1 Lake Raeside – Table 3.2.1 and provision 3.4.2: Monitoring observations

Table 3-3: Monitoring requirements for Lake Raeside as per L8337/2009/2 (Table 2.2.1).

Table 3.2.1: Monitoring of emissions to groundwater

Emission point reference

Parameter Units Frequency

Lake Raeside Volumetric Flow M3 Cumulative monthly

pH - Monthly During Discharge

TSS, TDS, WAD-CN, Na,

K, Ca, Mg, As, Pb, Ni, Fe,

Cd, Cr, Cu, Hg, Se, Zn, Cl,

CO3, HCO3, SO4, and NO3

Mg/L

During the 2016-2017 reporting period, no mine dewatering discharge from the Gwalia

operation to Lake Raeside occurred; St Barbara has not disposed of water into Lake

Raeside from underground dewatering since 2006. Consequently, no monitoring

observations were made of discharge to Lake Raeside during the reporting period.

Provision 3.4.2 of the licence states:

“For annual periods where a dewatering discharge into Lake Raeside has

occurred, the Licensee shall prepare a dewatering discharge report that

assesses environmental impacts associated with the mine dewater

discharge…”.


As no dewatering discharge to Lake Raeside occurred during the reporting period, no

dewatering discharge report was prepared for the period.

3.2.2 Tower Hill – Table 3.3.1: Monitoring observations

Table 3-4: Monitoring requirements for Tower Hill as per L8337/2009/2 (Table 3.3.1).

Table 3.3.1: monitoring of emissions to groundwater

Emission point reference

Parameter Units Frequency

Tower Hill Pit;

Harbour Lights Pit

Volumetric Flow M3 Cumulative monthly

pH - Six Monthly During

Discharge pH TSS, TDS, WAD-CN,

Na, K, Ca, Mg, As, Pb, Ni,

Fe, Cd, Cr, Cu, Hg, Se, Zn,

Cl, CO3, HCO3, SO4, and

NO3

Mg/L

As per monitoring requirements stipulated in Table 3.3.1 of Prescribed Premises Licence

L8337/2009/2, monitoring observations made during the reporting period for the Tower Hill

Pit are presented below and in Appendix B. During the 2016-2017 reporting period, no

discharge to the Harbour Lights Pit by St Barbara occurred.

During the 2016-2017 reporting period, approximately 673,327 m3 of water was discharged

to the Tower Hill Pit (Figure 3-2). This dewatering discharge rate is higher than that

undertaken during previous years of operation, reflecting the higher rainfall received by the

mine during the reporting period.

Figure 3-2: Tower Hill Pit discharge volumes (m3).


During the reporting period and across recent years of operation, pH observations of the

Tower Hill Pit lake have displayed a relatively stable trend at a pH level of ~8 (Figure 3-3).

Figure 3-3: Tower Hill Pit field and laboratory pH values.

In respect to Total Dissolved Solids (TDS) concentrations observed at the Tower Hill Pit,

the minimum value observed was 19,500 mg/L, the maximum 63,200 mg/L, with a mean

of 33,925 mg/L (Table 3-5). Tower Hill TDS observations throughout the reporting period

displayed a wide degree of variability, negatively associated with rainfall patterns which

produce dilution of the pit lake waters (Figure 3-4).

Figure 3-4: Tower Hill Pit Total Dissolved Solids concentrations (mg/L).

In respect to Total Suspended Solids (TSS) concentrations observed at the Tower Hill Pit,

the minimum value observed was 5 mg/L, the maximum 28 mg/L, with a mean of 12.5


mg/L (Table 3-5). Tower Hill TSS observations throughout the reporting period displayed

a wide degree of variability, positively associated with high intensity rainfall events which

transport sediments into the pit lake (Figure 3-4).

Figure 3-5: Tower Hill Pit Total Suspended Solids concentrations (mg/L).

Observations of WAD CN concentration during the reporting period have been under or

near the lower level of detection (Figure 3-6). The requirement to monitor WAD CN

concentrations in the Tower Hill Pit was added to Prescribed Premises Licence

L8337/2009/2 during the 2016 licence amendment; consequently WAN CN data was not

gathered during the entirety of the reporting period, and historical trending data is not

available.

Figure 3-6: Tower Hill Pit Weak Acid Dissociable cyanide (WAD CN) observations.


In respect to observations of analytes Na, K, Ca, Mg, As, Pb, Ni, Fe, Cd, Cr, Cu, Hg, Se,

Zn, Cl, CO3, HCO3, NO3, and SO4, results were reviewed in the context of previous years’

monitoring data (Appendix B – Monitoring Data: Tower Hill Monitoring Results), and (as

no licence trigger levels have been set) the Australian Drinking Water Guidelines (2011),

ANZ Guidelines for Fresh and Marine Water Quality (2000), and upstream control samples

taken on Lake Raeside. All analyte concentrations fell within acceptability criteria drawn

from these sources. The trending of analyte concentrations displayed variation consistent

with dilution by rainfall events.

Table 3-5: Tower Hill Pit Amalgamated Observations for the 2016 - 2017 reporting period showing Minima, Mean and Maxima values.

Tower Hill Pit - Amalgamated Observations

Analyte Unit Minimum Observation Mean Observation Maximum Observation

Field pH (blank) 7.69 7.91 8.22 pH (blank) 7.85 7.93 7.99 As mg/L 0.017 0.021 0.026

HCO3 mg/L 52.0 76.3 90.0 Ca mg/L 332.0 417.0 546.0

CO3 mg/L 1.000 1.000 1.000 Cd mg/L 0.000 0.000 0.001 Cl mg/L 10800.0 13966.7 18200.0 Cr mg/L 0.002 0.007 0.011 Cu mg/L 0.002 0.004 0.005

Fe (Total) mg/L 0.100 0.230 0.340 Hg mg/L 0.000 0.000 0.000 K mg/L 135.0 209.3 307.0

Mg mg/L 618.0 829.7 1110.0 Na mg/L 5700.0 7640.0 10200.0 Ni mg/L 0.027 0.036 0.048

NO3 mg/L 10.4 12.4 13.9 Pb mg/L 0.002 0.004 0.005 Se mg/L 0.020 0.040 0.050

SO4 mg/L 1430.0 1946.7 2880.0 TSS mg/L 5.000 12.500 28.000 TDS mg/L 19500.0 33925.0 63200.0

WAD CN mg/L 0.004 0.005 0.006 Zn mg/L 0.010 0.020 0.025


3.2.3 Gwalia TSF2 – Table 3.4.1: Monitoring observations

Table 3-6: Monitoring requirements for Gwalia TSF2 as per L8337/2009/2 (Table 3.4.1).

Table 3.4.1: Monitoring of ambient groundwater quality

Monitoring point reference and location

Parameter Units Averaging Period

Frequency

TSF 2/1 to TSF

2/12 Monitoring

Bores

SWL Metres

AHD

Spot Sample Six monthly

pH - Six Monthly During

Discharge TSD Mg/L

WAD-CN


L8337/2009/2, monitoring observations made during the reporting period in relation to

TSF2 groundwater bores are presented below and in Appendix C.

During the reporting period, Standing Water Levels observed at TSF2 monitoring bores

displayed a notable positive response to the extreme rainfall events experienced

throughout the period. Groundwater levels were beginning to decline towards the end of

the reporting period, but remain higher than those historically observed (Table 3-7).

Figure 3-7: Gwalia TSF2 monitoring bore standing water levels (mAHD).

In respect to field pH observed at the TSF2 monitoring bores, the minimum observation

was 6.28 (at TSF2/10), the maximum 7.55 (at TSF2/08), with a mean of 6.82 (Table 3-7).

All TSF2 bore pH observations were within the relatively neutral range (Figure 3-8).


Figure 3-8: Gwalia TSF2 monitoring bore field pH observations.

In respect to TDS concentrations observed at the TSF2 monitoring bores, the minimum

value observed was 632 mg/L (at TSF2/01), the maximum 153,000 mg/L (at TSF2/09),

with a mean of 80,173 mg/L (Table 3-7). TSF2 TDS observations displayed a degree of

variability consistent with historical data, with pronounced dips in TDS levels perhaps

associated with recharge driven by high intensity rain events (Figure 3-9).

Figure 3-9: Gwalia TSF2 monitoring bore total dissolved solids (TDS) observations.

In respect to WAD CN concentrations observed at the TSF2 monitoring bores, all values

were under the standard lower detection level of <0.04 mg/L (Figure 3-10; Table 3-7). One round of assays was conducted against a lower detection level of <0.004 mg/L,

with all results returning values above the standard lower detection level of <0.04 mg/L

(Figure 3-10; Table 3-7). The raw data for these bores are included in Appendix C.


Figure 3-10: Gwalia TSF2 monitoring bore weak acid dissociable cyanide (WAD CN) observations.

Table 3-7: Gwalia TSF2 bores 1-12 amalgamated observations for the 2016 - 2017 reporting period showing Minima, Mean and Maxima values.

Gwalia TSF2 Bores 1-12 - Amalgamated Observations


Field pH (blank) 6.28 6.84 7.55

pH (blank) 6.70 7.34 7.67

SWL mAHD 256.66 355.44 359.31

TDS mg/L 632 80174 153000

WAD_CN mg/L 0.004 0.031 0.040







Frequency

TSF 3/1 to TSF

3/7 Monitoring

Bores

SWL Metres

AHD

Spot Sample Monthly, while the plant is

operating;

quarterly while in care and

maintenance

TSF 3/1 to TSF

3/8 Monitoring

Bores

pH - Spot Sample Quarterly while the plant

is operating;

six monthly while in care

and maintenance

pH TSS, TDS,

WAD-CN, Na,

K, Ca, Mg, As,

Pb, Ni, Fe, Cd,

Cr, Cu, Hg,

Se, Zn, Cl,

CO3, HCO3,

SO4, and NO3

mg/L


L8337/2009/2, monitoring observations made during the reporting period in relation to

TSF3 groundwater bores are presented below and in Appendix D.

During the reporting period, Standing Water Levels observed at TSF3 monitoring bores

displayed a notable positive response to the high intensity rainfall events experienced

throughout the period; in the latter half of the reporting period, groundwater levels were

observed to decline towards pre-rain event levels (Figure 3-11). The groundwater level

rise and subsequent fall was observed to be of greater magnitude at bores spatially

associated with the site stormwater pit and adjacent to Lake Raeside.

The Standing Water Level monitoring requirement for groundwater bore TSF3/08 was

removed from Prescribed Premises Licence L8337/2009/2 following the first monitoring

instance of the reporting period. This licence amendment was made due to the casing

overtopping with groundwater, and observation that corrosion of the casing was resulting

in leakage from the well. These issues were referred to a hydrogeologist and Tailings

Storage Facility geotechnical engineer who concluded that the the Standing Water Level

at this bore was not reflective of groundwater head pressure, but of elevated pore

pressures produced by the weight of the Tailings Storage Facility compressing localised

water bearing material. On the basis of these conclusions, it was recommended that


Standing Water Level observations no longer be recorded at this well (Figure 3-11), but

that water sampling continue as previously required under the licence.

Figure 3-11: Gwalia TSF3 monitoring bore standing water levels (mAHD).

In respect to field pH observed at the TSF3 monitoring bores, the minimum observation

was 6.4 (at TSF3/01), the maximum 7.31 (at TSF3/06), while the mean field pH was 6.64

(Table 3-9). All TSF3 bore pH observations were within the relatively neutral range (Figure 3-12).

Figure 3-12: Gwalia TSF3 monitoring bore field pH observations.

In respect to TDS concentrations observed at the TSF3 monitoring bores, the minimum

value observed was 50,800 mg/L (at TSF3/04), the maximum 146,000 mg/L (at TSF3/07),

with a mean of 79,648 mg/L (Table 3-9). TSF3 TDS observations displayed a degree of

variability consistent with historical data (Figure 3-13).


Figure 3-13: Gwalia TSF3 monitoring bore TDS observations.

In respect to WAD CN concentrations observed at the TSF3 monitoring bores, all values were under or

very near to the standard lower detection level of <0.044 mg/L (Table 3-9; Figure 3-14). One round of

assays was conducted against a lower detection level of <0.004 mg/L.

Figure 3-14: Gwalia TSF3 monitoring bore weak acid dissociable cyanide (WAD CN)

observations.

In respect to observations of analytes Na, K, Ca, Mg, As, Pb, Ni, Fe, Cd, Cr, Cu, Hg, Se,

Zn, Cl, CO3, HCO3, NO3, and SO4, results were reviewed in the context of previous years’

monitoring data (

Appendix D - Monitoring Data: Gwalia TSF3 Monitoring Results), and (as no licence trigger

levels have been set) the Australian Drinking Water Guidelines (2011), ANZ Guidelines for

Fresh and Marine Water Quality (2000), and upstream control samples taken on Lake

Raeside. All analyte concentrations fell within acceptability criteria drawn from these

sources. All analyte concentrations displayed relatively stable levels across time.


Table 3-9: Gwalia TSF3 bores 1-8 amalgamated observations for the 2016 - 2017 reporting period showing Minima, Mean and Maxima values.

Gwalia TSF3 Bores 1-8 - Amalgamated Observations


Field pH (blank) 6.40 6.64 7.31

pH (blank) 6.95 7.27 7.57

As mg/L 0.01 0.01 0.02

HCO3 mg/L 78.00 136.30 214.00

Ca mg/L 531.00 1213.00 2550.00

CO3 mg/L 1 1 1

Cd mg/L 0.00 0.00 0.00

Cl mg/L 27000.00 41875.76 82200.00

Cr mg/L 0.01 0.06 0.23

Cu mg/L 0.01 0.02 0.07

Fe (Total) mg/L 0.25 1.25 13.40

Hg mg/L 0.0001 0.0002 0.0010

K mg/L 300.00 528.15 945.00

Mg mg/L 1540.00 2960.30 5590.00

Na mg/L 14300.00 24000.00 46100.00

Ni mg/L 0.01 0.03 0.19

NO3 mg/L 0.48 6.81 13.90

Pb mg/L 0.01 0.01 0.02

Se mg/L 0.05 0.14 0.20

SO4 mg/L 1220.00 6376.67 13000.00

TDS mg/L 50800.00 79648.48 146000.00

WAD CN mg/L 0.00 0.03 0.04

Zn mg/L 0.05 0.08 0.15







Frequency

TSF 4/1 to TSF

4/6 Monitoring

Bores

SWL Metres

AHD

Spot Sample Monthly, while the plant is

operating; quarterly while in

care and maintenance

pH - Spot Sample Quarterly while the plant is

operating; six monthly while

in care and maintenance

pH TSS, TDS,

WAD-CN, Na,

K, Ca, Mg, As,

Pb, Ni, Fe, Cd,

Cr, Cu, Hg,

Se, Zn, Cl,

CO3, HCO3,

SO4, and NO3

mg/L

Construction of TSF4 was not undertaken during the 2016-2017 reporting period and

therefore no compliance monitoring was conducted.

3.3 Compliance Report Table 3-11: Annual compliance reporting requirement for L8337/2009/2 (Table 4.2.1).


Condition or table

(if relevant)

Parameter Format or form

4.1.2 Compliance Compliance Report

The Annual Audit Compliance report for L8337/2009/2 has been submitted to the DWER

as of October 2017. This AACR has been included with this Annual Environmental Report

as Appendix A - Annual Audit Compliance Report.


3.4 Complaints Summary Table 3-12: Annual complaint reporting requirement for L8337/2009/2 (Table 4.2.1).


Condition or table

(if relevant)

Parameter Format or form

4.1.3 Complaints summary None Specified

During the 2016 – 2017 reporting period, no complaints were communicated to the

premises covered under L8337/2009/2.

3.5 Monitoring equipment calibration data

Provision 3.1.3 of Prescribed Premises Licence L8337/2009/2 states:

“The Licensee shall ensure that all monitoring equipment used on the Premises

to comply with the conditions of this Licence is calibrated in accordance with the

manufacturer's specifications.”

Provision 4.2.2.a of the Licence further also states:

“The Licensee shall ensure that the Annual Environmental Report also contains:

(a) any relevant process, production or operational data recorded under

Condition”

As per these Licence provisions, the calibration records for the Gwalia field EC/TDS meter

has been included below (Figure 3-15, Table 3-13).


Figure 3-15: Calibration sheet for the first, second and third monitoring period.

Table 3-13: Transcription of the calibration records for the fourth monitoring period.

Field Calibration Record

Batch # 16/2604 16/2604 15/1706 SLOPE RANGE 85 105

Expiry Date: Apr-18 Apr-18 Jun-18

Date pH 4 Slope pH 7 Slope EC Temp

14/09/2017 4 91.3 7 91.2 58 22.5

16/09/2017 4 95.3 7 87 58 19.8

17/09/2017 4 88.4 7 87 58 18.6


3.6 Construction and compliance documentation relating to Gwalia TSF4

Provision 4.2.3 of Prescribed Premises Licence L8337/2009/2 states:

“For each stage of the TSF4 works described in Table 1.2.3 and Table 1.2.4,

and following completion of construction of the landfill described in Table 1.2.4,

the Licensee shall submit a compliance document to the CEO.”

Provision 4.2.4 of the Licence states:

“The compliance document shall:

(a) certify that the works were constructed in accordance with the conditions of

this Licence;

(b) be signed by a person authorised to represent the Licensee and contain the

printed name and position of that person within the company.”

As construction of TSF4 was not undertaken during the 2016-2017 reporting period, the

requirements of conditions 4.2.3 and 4.2.4 have not been detailed within this AER.

Appendix A - Annual Audit Compliance Report

Department of Water and Environmental Regulation

1

Annual Audit Compliance Report Form

Annual Audit Compliance Report Form Environmental Protection Act 1986, Part V

Section A – Licence Details Licence number: L8337/2009/2 Licence file number: 2012/0006861

Licence holder: St Barbara Limited

Trading as: St Barbara Ltd

ACN: 009 165 066

Registered address: Level 10, 432 St Kilda Road, Melbourne VIC 3004

Reporting period: 01/09/2016 to 31/08/2017

Section B – Statement of Compliance with Licence Conditions Did you comply with all of your licence conditions during the reporting period? (please tick the appropriate box) ☐Yes – please complete:

section C; section D if required; and sign the declaration in Section F.

☒No – please complete:

section C; section D if required; section E; and sign the declaration at Section F.

Section C – Statement of Actual Production Provide the actual production quantity for this reporting period. Supporting documentation is to be attached.

Prescribed Premises Category Actual Production Quantity 5 - Processing or beneficiation of metallic or non-metallic ore 827,534 t

73 - Bulk storage of chemicals 374 m3 fixed bulk; <500 m3 aggregate

Section D – Statement of Actual Part 2 Waste Discharge Quantity Provide the actual Part 2 waste discharge quantity for this reporting period. Supporting documentation is to be attached.

Prescribed Premises Category Actual Part 2 Waste Discharge Quantity 6 – Mine Dewatering 673,327 kL 52 - Electric power generation: premises (other than premises within category 53 or an emergency or standby power generating plant on which electrical power is generated using a fuel

12 MW

89 - Class II putrescible landfill site ~1,600 tonnes


2


Section E – Details of Non-Compliance with Licence Condition Please use a separate page for each condition with which the licence holder was non-compliant at a time during the reporting period.

Condition no: 1.2.4 Date(s) of non-compliance: 25th March 2017

Details of non-compliance:

During the period of 22nd to 25th of March, the Gwalia mine site experienced approximately 180 mm of rainfall, the majority occurring on the night of the 24th. The morning of the 25th at 11:30 AM, the Processing Superintendent was inspecting the TSF3 toe drain and noted it had been filled with significant amounts of rainwater from the TSF3 embankments. At the terminal section of the TSF3 toe drain (Figure 1), a 20 cm wide breach was observed where water had started to flow from the TSF toe drain into the flooded Lake Raeside. A loader was immediately organised to repair the breach. In the intervening 20 minutes the gap created by the flow widened to 1.5 - 2 m with water exiting at a slow pace. The loader sealed the breach stopping the immediate discharge. On the night of the 25th, the level in Lake Raeside rose due to further rains and the morning of the 26th at approximately 7:00 AM the repaired bund was inundated and flood waters started to flow into the TSF3 toe drain (Plate 3). At this stage the water levels reached equilibrium. At approximately 11:30 AM, the lake level began to recede and the flow from the toe drain to the lake was re-established (Plate 4). What was the actual (or suspected) environmental impact of the non-compliance? NOTE – please attach maps or diagrams to provide insight into the precise location of where the non-compliance took place. Analytical samples taken from the toe drain water on the 5th of February showed a WAD CN concentration of 0.056 mg/l. Samples from the toe drain and receiving environment (Figure 1) were taken to determine potential impacts and are summarised below in Table 1: Table 1: Summary of WAD CN analysis post-incident.

Location: CN WAD (mg/L) ITBD1 (28/3/17) <0.040 ITBD2 (28/3/17) <0.040 ITBC1 (28/3/17) <0.040 ITB1 (28/3/17) 0.058 ITBI2 (28/3/17) <0.040

Toe drain (5/2/17) 0.056 The analytical results indicated that only the water within the toe drain contained any detectable WAD CN. The surrounding sampling points did not contain WAD CN at any detectable level. The full Analytical report has been included as Appendix A. Cause (or suspected cause) of non-compliance: Due to the very significant amount of rain in a short period of time of 180 mm in a 96 hour period (mean annual rainfall of Leonora is 236 mm) the water level in Lake Raeside (an ephemeral Salt Lake) rose dramatically. In addition to this, the increased runoff from TSF3 into the toe drain caused the internal water level of the drain to rise in parallel. The toe drain bund in the terminal section was unable to cope with this dramatic rise in internal and external water levels and a breach formed.


3


Action taken to mitigate any adverse effects of non-compliance and prevent recurrence of the non-compliance: The initial breach was blocked using a loader on the 25/7/17 (Plate 2). Access to the area was very difficult due to flood and wet conditions and as the water level continued to rise the site was deemed not safe to conduct the repairs and the works halted. After the second breach occurred on the night of the 25th, St Barbara mobilised equipment to build up and stabilize the breached section of the toe drain (Plate 5). These works were finalised and the bund terminal height for the toe drain bund increased by approximately 1 m (Plate 6 and Plate 7). Was this non-compliance previously reported to DWER?

Yes, and

Reported to DWER verbally Date: / /

Reported to DWER in writing Date: 26/03/2017


4


Figure 1: Table incident (25/3/17) TSF3 Toe-drain breach and post breach sampling points.


5


Plate 1: Photograph (P2) showing the water levels and spatial relationship between the TSF toe drain (left of frame) and Lake Raeside (Right of Frame).

Plate 2: Photograph (P1) facing west showing the immediate repair works on the TSF toe drain.


6


Plate 3: Photograph (P4) showing the reversal of flows with water from Lake Raeside flowing into the TSF toe drain.

Plate 4: Photograph (P3) showing the flow of water from the TSF toe drain to Lake Raeside


7


Plate 5: Photograph of excavator work conducted to repair the toe drain breach and build up immediate area (27/3/17).

Plate 6: Photograph showing the repairs to TSF3 toe drain bund (27/3/17).


8


Plate 7: Photograph showing the finalised repair works to the TSF3 toe drain bund.


9


Section E – Details of Non-Compliance with Licence Condition Please use a separate page for each condition with which the licence holder was non-compliant at a time during the reporting period.

Condition no: 1.2.1 Date(s) of non-compliance: 9th December 2016

Details of non-compliance:

License condition 1.2.1 requires that all pipelines containing tailings slurry, decant water, mine dewater or effluent are either:

(a) equipped with telemetry systems or pressure sensors along pipelines to allow the detection of leaks and failures:

(b) equipped with automatic cut-outs in the event of a pipe failure: or (c) provided with secondary containment sufficient to contain any spill for a period equal to

the time between routine inspections. Condition 1.2.1 was introduced in the newly issued license on the 9th of December 2016. The previous license issued on the 7th of February 2014 required under condition W2(a) “The licensee shall ensure that all pipelines containing saline, alkaline or cyanide constituents are either buried or sited within appropriately bunded facilities. This includes but it is not limited to tailings delivery lines, return water lines and saline water lines.” St Barbara was compliant with condition W2 (a) of the license by having most of the pipelines buried and the rest bunded. Once the new license was issued, St Barbara was unable to comply with condition 1.2.1 automatically. This potential non-compliance was notified to the DWER after St Barbara received the draft license on the 16th of November and before the License was issued. What was the actual (or suspected) environmental impact of the non-compliance? NOTE – please attach maps or diagrams to provide insight into the precise location of where the non-compliance took place. No environmental impact

Cause (or suspected cause) of non-compliance: Change in license conditions

Action taken to mitigate any adverse effects of non-compliance and prevent recurrence of the non-compliance: A flowmeter calibration instrument was purchased and all flow meters were tested. The Site electricians were trained in using the calibration instrument, installing and

maintaining telemetry systems. New flow meters were ordered and installed on the bore field pipelines and telemetry is

operational with a few bores still requiring a flow meter before the IT telemetry system can be set up.

Telemetry system was set up and is operational on the slurry discharge into TSF 3. The decant return pipeline telemetry was ordered but due to the TSF 3 lift works, the


10


installation could not be undertaken. This is estimated to be operational early next year. The old telemetry system on the mine dewatering pipeline including the flow meters had to

be replaced. One of the required flow meters was replaced with a new mag flow system and is operational with the second one being replaced and the telemetry system set up and operational before the end of the year.

Was this non-compliance previously reported to DWER?

Yes, and

Reported to DWER verbally Date: / /

Reported to DWER in writing Date: 06/11/2016


12


Appendix A – Analytical report for samples taken following the breach in TSF toe drain bund incident.


1



2



3



4


1 It is an offence under section 112 of the Environmental Protection Act 1986 for a person to give information on this form that to their knowledge is false or misleading in a material particular. 2 AACRs can only be signed by the licence holder or an authorised person with the legal authority to sign on behalf of the licence holder.

Appendix B – Monitoring Data: Tower Hill Monitoring Results

Tower Hill Pit Monitoring Parameters Date Nov-16 Feb-17 Jun-17 Sep-17

Field pH (blank) 7.69 7.85 7.89 8.22 pH (blank) 7.91 7.85 7.99 7.95 As mg/L - 0.026 0.017 0.021

HCO3 mg/L - 90 52 87 Ca mg/L - 546 332 373

CO3 mg/L - 1 1 1 Cd mg/L - 0.0005 0.0004 0.0005 Cl mg/L - 18200 10800 12900 Cr mg/L - 0.011 0.002 0.008 Cu mg/L - 0.005 0.002 0.005

Fe (Total) mg/L - 0.34 0.1 0.25 Hg mg/L - 0.0001 0.0001 0.0001 K mg/L - 307 135 186

Mg mg/L - 1110 618 761 Na mg/L - 10200 5700 7020 Ni mg/L - 0.048 0.027 0.032

NO3 mg/L - 13.9 10.4 12.9 Pb mg/L - 0.005 0.002 0.005 Se mg/L - 0.05 0.02 0.05

SO4 mg/L - 2880 1530 1430 TSS mg/L 5 28 9 8 TDS mg/L 63200 31200 19500 21800

WAD CN mg/L - 0.004 0.005 0.006 Zn mg/L - 0.025 0.01 0.025

Appendix C - Monitoring Data: Gwalia TSF2 Monitoring Results

Field pH pH SWL TDS WAD_CN

(blank) (blank) mAHD mg/L mg/L

Nov-16 6.96 7.29 357.36 64100 0.04

Feb-17 7.48 7.61 359.31 632 0.004

Jun-17 7.08 7.5 357.98 70300 0.04

Sep-17 7.17 7.59 357.79 73200 0.04

Nov-16 7 7.28 357.42 56300 0.04

Feb-17 6.81 7.21 358.05 60800 0.004

Jun-17 7.03 7.46 359.02 55500 0.04

Sep-17 7.01 7.56 357.89 57600 0.04

Nov-16 6.51 7.01 356.22 112000 0.04

Feb-17 6.58 7.07 256.66 115000 0.004

Jun-17 6.89 7.19 356.55 124000 0.04

Sep-17 6.63 7.32 356.48 120000 0.04

Nov-16 6.74 7.09 355.97 124000 0.04

Feb-17 6.93 7.22 356.27 128000 0.004

Jun-17 7 7.51 356.83 49600 0.04

Sep-17 6.87 7.36 356.69 121000 0.04

Nov-16 6.88 7.35 356.94 47400 0.04

Feb-17 6.5 7.39 357.25 51400 0.004

Jun-17 6.84 7.45 357.19 47500 0.04

Sep-17 6.79 7.61 357.18 47900 0.04

Nov-16 6.7 7.19 356.58 68600 0.04

Feb-17 6.7 7.2 357.12 95100 0.004

Jun-17 6.95 7.42 356.99 92200 0.04

Sep-17 6.78 7.49 356.92 80900 0.04

Sample Point Date

Gwalia TSF2 Bores Table 1 of 2

GW TSF2/01

GW TSF2/02

GW TSF2/03

GW TSF2/04

GW TSF2/05

GW TSF2/06

Field pH pH SWL TDS WAD_CN

(blank) (blank) mAHD mg/L mg/L

Nov-16 6.9 7.36 357.51 32500 0.04

Feb-17 6.73 7.38 358.03 41300 0.004

Jun-17 6.96 7.6 358.11 33400 0.04

Sep-17 7.04 7.63 358.03 32600 0.04

Nov-16 7.55 7.67 357.78 38000 0.04

Feb-17 6.83 7.4 357.85 33800 0.005

Jun-17 7 7.61 358.53 35800 0.04

Sep-17 6.97 7.65 358.48 36900 0.04

Nov-16 6.3 6.86 357.05 132000 0.04

Feb-17 6.44 6.7 357.47 89500 0.004

Jun-17 6.46 7.09 357.45 146000 0.04

Sep-17 6.83 7.2 357.39 153000 0.04

Nov-16 6.53 6.99 356.14 133000 0.04

Feb-17 6.32 6.98 356.44 144000 0.004

Jun-17 6.48 7.05 356.55 139000 0.04

Sep-17 6.28 7.16 356.5 142000 0.04

Nov-16 7.47 7.5 358.38 78700 0.04

Feb-17 7.02 7.45 358.82 72800 0.004

Jun-17 6.91 7.44 359.17 93100 0.04

Sep-17 7.13 7.54 359.03 104000 0.04

Nov-16 7.34 7.61 357.97 50400 0.04

Feb-17 6.74 7.27 358.09 81800 0.01

Jun-17 6.5 7.44 358.84 67100 0.04

Sep-17 6.73 7.48 358.75 74600 0.04

Gwalia TSF2 Bores Table 2 of 2

Sample Point Date

GW TSF2/12

GW TSF2/07

GW TSF2/08

GW TSF2/09

GW TSF2/10

GW TSF2/11

Appendix D - Monitoring Data: Gwalia TSF3 Monitoring Results

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