[2018] FCA 1502
Verde Terra Pty Ltd v Central Coast Council
Judgment (132 paragraphs)
[1]
Introduction
The Environment Protection Authority (the EPA) (the prosecutor) has charged Maules Creek Coal Pty Ltd ACN 140 533 875 (the defendant) with four offences under the Protection of the Environment Operations Act 1997 (NSW) (POEO Act). The alleged offences relate to the Maules Creek open cut coal mine (the mine) located at Therribi Road, Boggabri in north-west NSW (the premises), and concern blast HRN_08_39_OB (the blast), carried out at the mine on 20 August 2020 in the course of mining for coal. The blast had originally been scheduled to be carried out on 19 August 2020 at 3:30pm.
The mine is an open cut coal mine approximately 45km to the southeast of Narrabri and approximately 16km to the north-northeast of Boggabri. The mine is approximately 1.3km to the north of the Boggabri coal mine, and 5.2km to the north of the Tarrawonga coal mine. Mining operations commenced at the mine in 2014.
At all relevant times, the defendant held environment protection licence number 20221 (the EPL) issued under s 55 of the POEO Act on 2 May 2013.
At all relevant times, Whitehaven Coal Limited (ACN 124 425 396) (Whitehaven Coal) was the ultimate holding company for the defendant.
The proceedings were heard before me between 30 January and 3 February 2023, 6 and 10 February 2023, 18 and 21 September 2023, and 13 and 16 November 2023.
The procedural history is summarised in the Court's interlocutory judgment in Environment Protection Authority v Maules Creek Coal Pty Ltd [1] (Maules Creek (No 1)) at [2]-[28]. On 15 September 2023, in Maules Creek (No 1), the Court made the following order at [94]: "The defendant's application that Pritchard J recuse herself from hearing these proceedings is dismissed."
The defendant sought leave to appeal against that interlocutory order pursuant to s 5F(3)(a) of the Criminal Appeal Act 1912 (NSW) (Criminal Appeal Act). On 3 November 2023, in Maules Creek Coal Pty Ltd v Environment Protection Authority, [2] the Court of Criminal Appeal (CCA) (Leeming, Payne and Kirk JJA, Wilson and Fagan JJ), granted the defendant leave to appeal and dismissed the appeal from the Court's decision in Maules Creek (No 1).
[2]
The timing charge: proceeding 2021/234554
By amended summons filed on 13 December 2021 in proceeding 2021/234554, the prosecutor alleges that between about 4 August 2020 and 20 August 2020, at or near the mine, the defendant committed an offence against s 64(1) of the POEO Act in that it was the holder of an environment protection licence, a condition of which was contravened by a person (the timing charge).
The particulars of the timing charge are as follows:
a. Licence
Environment Protection Licence Number 20221 (EPL).
b. Licence condition contravened
Condition O1.1 of the EPL, which states: "Licensed activities must be carried out in a competent manner. This includes:
(a) the processing, handling, movement and storage of materials and substances used to carry out the activity; and
(b) the treatment, storage, processing, reprocessing, transport and disposal of waste generated by the activity."
c. The licenced activities
The licenced activities that were carried out by Defendant at the Licenced Premises were blast HRN_08_39_OB (the Blast) in the course of mining for coal.
d. Manner of contravention
The Defendant did not carry out the licensed activities in a competent manner it programmed the electronic initiation system for the Blast with a burden relief time of 0.8 - 1.5 ms/m, which did not provide good progressive release of burden as required under section 3.3.5 of the Defendant's Blast Management Plan.
[3]
The stemming length charge: proceeding 2021/234556
By summons filed on 16 August 2021 in proceeding 2021/234556, the prosecutor alleges that between about 4 August 2020 and 20 August 2020, at or near the mine, the defendant committed an offence against s 64(1) of the POEO Act in that it was the holder of an environment protection licence, a condition of which was contravened by a person (the stemming length charge).
The particulars of the stemming length charge are as follows:
a. Licence
Environment Protection Licence Number 20221 (EPL).
b. Licence condition contravened
Condition O1.1 of the EPL, which states: "Licensed activities must be carried out in a competent manner This includes:
(a) the processing, handling, movement and storage of materials and substances used to carry out the activity; and
(b) the treatment, storage, processing, reprocessing, transport and disposal of waste generated by the activity"
c. The licenced activities
The licenced activities that were carried out by the Defendant at the Licenced Premises was the carrying out of blast HRN_08_39_OB (the Blast) in the course of mining for coal.
d. Manner of contravention
The Defendant did not carry out licensed activities in a competent manner because it designed the Blast with a stemming length for the blast holes of 3.0m, which deviated from the Defendant's Approved Design Standard ST_HRN_229_OB_D_1.
[4]
The overloading charge: proceeding 2021/234557
By summons filed on 16 August 2021 in proceeding 2021/234557, the prosecutor alleges that between about 4 August 2020 and 20 August 2020, at or near the mine, the defendant committed an offence against s 64(1) of the POEO Act in that it was the holder of an environment protection licence, a condition of which was contravened by a person (the overloading charge).
The particulars of the overloading charge are as follows:
a. Licence
Environment Protection Licence Number 20221 (EPL).
b. Licence condition contravened
Condition O1.1 of the EPL, which states: "Licensed activities must be carried out in a competent manner. This includes:
(a) the processing, handling, movement and storage of materials and substances used to carry out the activity; and
(b) the treatment, storage, processing, reprocessing, transport and disposal of waste generated by the activity."
c. The licenced activities
The licenced activities that were carried out by the Defendant at the Licenced Premises was the carrying out of blast HRN_08_39_OB (the Blast) in the course of mining for coal.
d. Manner of contravention
The Defendant did not carry out the licensed activities in a competent manner because it overloaded approximately 19% of blast holes for the Blast with more than 10% of the amount of explosives prescribed in the design for the Blast, which was in contravention of the Defendant's procedure for loading and stemming blast holes (WHC-PRO-OC-LOADING AND STEMMING).
[5]
The emission of noise charge: proceeding 2021/234558
By summons filed on 16 August 2021 in proceeding 2021/234558, the prosecutor alleges that between about 4 August 2020 and 20 August 2020, at or near the mine, the defendant committed an offence against s 140(1) of the POEO Act in that as the occupier of the licensed premises, it dealt with materials in or on the premises in such a manner as to cause the emission of noise from the licensed premises, and the noise so caused (or any part of it) was caused by its failure to deal with those materials in a proper and efficient manner (the emission of noise charge).
The particulars of the emission of noise charge are as follows:
a. Materials:
896,256kg of explosives, consisting of primarily:
a) XL60-100; and
b) XLOAD70-110.
(the Explosives)
b. Manner of dealing:
The Explosives were dealt with at the Premises during blast HRN_08_39_OB (the Blast) by:
i. stemming blast holes loaded with the Explosives to 3m; and
ii. detonating the Explosives using excessively fast timing of the electronic initiation system to detonate the explosives.
c. The manner of dealing was not proper and efficient
The manner of dealing with the Explosives was not proper and efficient as it resulted in the dispersion of excessive explosive energy upwards into the atmosphere, thereby reducing the explosive energy of the Blast directed towards the breaking of cap rock or overburden that was the intended purpose of dealing with the Explosives.
d. Emission of noise from the Premises:
The manner of dealing with the Explosives resulted in an explosion that caused the emission of noise from the Premises in the form of sound and vibrations resulting from airblast overpressure.
[6]
Issues
The key issues which arise for determination in relation to the four charges include:
1. the construction of s 64(1) of the POEO Act in relation to the contravention of any condition of a licence;
2. the construction of condition O1.1 of the EPL, and in particular the requirement that licensed activities must be carried out in "a competent manner";
3. whether, as particularised in the timing charge, the defendant did not carry out the blast in a competent manner when it allegedly programmed the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m;
4. whether, as particularised in the stemming length charge, the defendant did not carry out the blast in a competent manner when it allegedly designed the blast with a stemming length for the blast holes of 3.0m;
5. whether, as particularised in the overloading charge, the defendant did not carry out the blast in a competent manner when it allegedly overloaded approximately 19% of blast holes for the blast with more than 10% of the amount of explosives prescribed in the design for the blast;
6. the construction of s 140(1) of the POEO Act in relation to dealing with materials in or on premises in such a manner as to cause the emission of noise, and the question of the occupier's failure to deal with those materials in "a proper and efficient manner";
7. whether, as particularised in the emission of noise charge, the manner of dealing with the explosives resulted in an explosion that caused the emission of noise from the premises in the form of sound vibrations resulting from airblast overpressure; and
8. whether, as particularised in the emission of noise charge, the defendant's dealing with the explosives was not proper and efficient as it resulted in the dispersion of "excessive explosive energy upwards into the atmosphere, thereby reducing explosive energy of the blast directed towards the breaking of cap rock or overburden that was the intended purpose of dealing with the [e]xplosives".
[7]
Outcome
For the reasons below, I have decided as follows:
1. in relation to the timing charge, the prosecutor has established beyond reasonable doubt that the defendant is guilty of an offence against s 64(1) of the POEO Act of contravening condition O1.1 of the EPL in not carrying out licensed activities in a competent manner;
2. in relation to the stemming length charge, the prosecutor has established beyond reasonable doubt that the defendant is guilty of an offence against s 64(1) of the POEO Act of contravening condition O1.1 of the EPL in not carrying out licensed activities in a competent manner;
3. in relation to the overloading charge, the prosecutor has established beyond reasonable doubt that the defendant is guilty of an offence against s 64(1) of the POEO Act of contravening condition O1.1 of the EPL in not carrying out licensed activities in a competent manner; and
4. in relation to the emission of noise charge, the prosecutor has established beyond reasonable doubt that the defendant is guilty of an offence against s 140(1) of the POEO Act of causing the emission of noise and the noise was caused by its failure to deal with materials in a proper and efficient manner.
As the prosecutor has requested that no final orders be made today, 4 October 2024, in order to allow it to consider its position in relation to any application pursuant to s 5AE of the Criminal Appeal Act, I will stand each summons over until 31 October 2024 at 4pm for the entry of final orders.
[8]
Factual background
The following factual background is derived in part from the brief statement of agreed facts filed on 2 December 2022 (the SOAF), largely from the Court's consideration of the documents attached to the SOAF and otherwise tendered by the parties, and also from the evidence of witnesses which was not the subject of objection or in relation to which objections were overruled. In their written submissions, each of the parties identified facts which they submitted the Court should find. Numerous of the "facts" so identified were in the nature of submissions.
[9]
The defendant
At all relevant times, the defendant operated the mine.
In carrying out mining operations at the mine, the defendant carried out activities which were "scheduled activities" within the meaning of the POEO Act.
[10]
The EPL
On 2 May 2013, Mr Robert O'Hern (a delegate of the EPA) granted the defendant's application pursuant to s 55 of the POEO Act for the issue of the EPL, subject to conditions, in relation to the scheduled activities carried out at the mine. As at 2 December 2022, the EPL had been last varied by the EPA on 27 November 2019. The EPL authorised and regulated the carrying out of the scheduled activities and specifically regulated aspects of mine blasting.
The administrative conditions in the EPL are as follows:
1 Administrative Conditions
A1 What the licence authorises and regulates
A1.1 This licence authorises the carrying out of the scheduled development work listed below at the premises listed in A2:
Construction of mine related infrastructure.
A1.2 This licence authorises the carrying out of the scheduled activities listed below at the premises specified in A2. …
Unless otherwise further restricted by a condition of this licence, the scale at which the activity is carried out must not exceed the maximum scale specified in this condition.
…
A3 Other activities
A3.1 This licence applies to all other activities carried on at the premises, including:
Ancillary Activity
Chemical storage
Concrete works
Crushing, grinding and separating of rock for construction activities
Railway systems activities
Sewerage treatment system
A4 Information supplied to EPA
A4.1 Works and activities must be carried out in accordance with the proposal contained in the licence application, except as expressly provided by a condition of this licence.
…
The conditions concerning discharges to air and water and applications to land include, relevantly, the following:
2 Discharges to Air and Water and Applications to Land
…
P1.4 The following points referred to in the table below are identified in this licence for the purposes of weather and/or noise monitoring and/or setting limits for the emission of noise from the premises.
…
The limit conditions (the limit conditions) in relation to blasting are, relevantly, as follows:
3 Limit Conditions
…
L3 Noise limits
…
L4 Blasting
L4.1 The airblast overpressure level from blasting operations in or on the premises must not exceed 120dB (Lin Peak) at any time at monitoring points 31, 32, 33, or 34 as defined in Condition P1.4 of this licence.
L4.2 The airblast overpressure level from blasting operations in or on the premises must not exceed 115dB (Lin Peak) for more than five per cent of the total number of blasts over each reporting period at any time and at monitoring points 31, 32, 33, or 34 as defined in Condition P1.4 of this licence.
L4.3 The ground vibration peak particle velocity from the blasting operations carried out in or on the premises must not exceed 10mm/sec at any time at monitoring points 31, 32, 33, or 34 as defined in Condition P1.4 of this licence.
L4.4 The ground vibration peak particle velocity from the blasting operations carried out in or on the premises must not exceed 5mm/sec for more than five per cent of the total number of blasts over each reporting period at monitoring points 31, 32, 33, or 34 as defined in Condition P1.4 of this licence.
…
L4.7 Blasting at the premises is limited to 1 blast on each day on which blasting is permitted.
…
L4.8 Condition L4.7 does not apply to blasts that generate ground vibration of 0.5mm/s or less at any residence on privately-owned land, or to blasts required to ensure the safety of the mine or its workers.
Note: For the purposes of this condition, a blast refers to a single blast event, which may involve a number of individual blasts fired in quick succession in a discrete area of the mine.
[11]
The EPA Act approval
On 23 October 2012, as delegate of the Minister for Planning and Infrastructure, the Planning Assessment Commission of NSW approved the mine, subject to conditions, pursuant to the now repealed s 75J of the Environmental Planning and Assessment Act (NSW) (EPA Act) (application number 10_0138) (the EPA Act approval).
Condition 18 of the EPA Act approval provides as follows in relation to blasting criteria:
BLASTING
Blasting Criteria
18. The Proponent shall ensure that the blasting on the site does not cause exceedances of the criteria in Table 7.
Table 7: Blasting criteria
However, these criteria do not apply if the Proponent has a written agreement with the relevant owner or infrastructure provider/owner, and the Proponent has advised the Department in writing of the terms of this agreement.
Condition 25 of the EPA Act approval provides as follows in relation to the preparation and implementation of a blast management plan:
Blast Management Plan
25. The Proponent shall prepare and implement a Blast Management Plan for the project to the satisfaction of the Director-General. This plan must:
(a) be submitted to the Director-General for approval prior to undertaking any blasting activities on the site;
(b) be prepared in consultation with the EPA and interested members of the local community potentially affected by blasting operations;
(c) propose and justify any alternative ground vibration limits for public infrastructure in the vicinity of the site;
(d) describe the measures that would be implemented to ensure:
• best management practice is being employed; and
• compliance with the relevant conditions of this approval;
(e) include a road closure management plan for blasting within 500 metres of a public road, that has been prepared in consultation with Council;
(f) include a specific blast fume management protocol to demonstrate how emissions will be minimised including risk management strategies if blast fumes are generated;
(g) include a monitoring program for evaluating the performance of the project including:
• compliance with the applicable criteria; and
• minimising fume emissions from the site; and
(h) include a Leard Forest Mining Precinct Blast Management Strategy that has been prepared in consultation with the other mines within the Leard Forest Mining Precinct to minimise the cumulative blasting impacts of all the mines within the precinct.
[12]
Problems in achieving adequate fragmentation in the Velyama seam in November 2019
In November 2019, the defendant experienced problems in achieving adequate fragmentation in the upper parts of the Velyama seam at the mine. This prompted Mr Jorge Moraga, the mine's general manager, to contact Dr Cameron McKenzie, an expert in relation to matters concerning mine blasting. Dr McKenzie attended the mine over 3 days, and produced a report dated December 2019, titled "Review of Blasting Practices at Maules Creek Coal Mine" (Dr McKenzie's 2019 report).
Dr McKenzie's 2019 report included options of reducing stemming length and adopting fast initiation timing to address the fragmentation problems. One measure for improvement of fragmentation identified was a reduction in the stemming length for each of the blast holes (emphasis added):
[t]o maximise the vertical distribution of the explosive and improve fragmentation in the stem zone, stemming lengths must be minimized consistent with maintaining fly rock safety.
…
[f]or best fragmentation in the hard cap area, stemming length is recommended to be in the range of 3 to 3.5 metres, and blast clearance distances in the range 600 to 500 metres respectively.
Stemming is the amount of inert material which sits in the blast hole above the explosive blast material. "Stemming length" is the distance between the top of the explosive charge and the surface of the blast that is usually filled with stemming material (that is, inert material loaded on top of or between the explosive charges). The defendant's Whitehaven Coal Drill and Blast Design Standard Fixed Pattern also known as "ST_HRN_229_OB_D_1" (the design standard) dated 16 October 2019 specified a stemming length of 3.5m under the heading "Loading Parameters".
The defendant submitted, and I find, that the fragmentation problems then being experienced by the defendant were in the coarse upper flitch of the interburden of the Velyama seam, as opposed to the coarse fragmentation of the overburden on the Herndale seam which was the issue which gave rise to the subsequent retainer of Dr McKenzie in August 2020. Interburden is waste rock between coal seams, whilst overburden is the waste rock sitting above the upper most coal seam.
Another improvement measure identified by Dr McKenzie in his 2019 report was using fast timing conducted with electronic initiation.
[13]
The Herndale seam and the previous blast on 7 August 2020
The blast on 20 August 2020 was carried out on the Herndale seam, one of the coal seams at the mine.
On 7 August 2020, the defendant carried out an overburden blast in a location adjacent to the location of the blast which was carried out on 20 August 2020 on the "relevant part of the Herndale seam (HRN 08_40_OB)" (the previous blast). The previous blast was carried out after blasting and excavation in the Herndale area had restarted for the first time in 2 years. The previous blast used a stemming length of 4.0m.
Between 7 and 13 August 2020, in the period after the previous blast was fired, it became evident when mine workers were digging and loading the "muck pile" that the previous blast had not achieved adequate fragmentation of the caprock which resulted in poor digging conditions and safety risks to workers during loading activities. Muck pile is a reference to broken rock. Caprock is the name given to the rock or rock-like conglomerate material forming part of the overburden that lies at or near the ground surface within the same stratum as the stemming that sits in the blast holes above the explosive charge. Mr Ryan Gomez, technical services superintendent at the mine at all relevant times, testified that in lay person's terms, caprock is "large boulders".
The defendant contended, and I find, that achieving adequate fragmentation of rock is recognised as a "key objective of mine blasting", it being an objective directed to both the safety of workers and the efficient commercial operation of the mine by enabling an efficient dig rate. If caprock is not adequately fragmented, a consequence is that "workers operating certain plant, including the trucks into which the overburden is loaded, are exposed to a risk of back and neck and body-jarring injuries that may be caused when large heavy pieces of rock are dug up and loaded into the trucks". Another consequence is that "the mining operations involving the digging and removal of the overburden become more time consuming and less cost efficient, because it takes more time for the diggers to dig up larger rocks when the cap rock is not adequately fragmented".
[14]
Preparation for the blast scheduled for 19 August 2020
On around 4 August 2020, the design of the blast originally scheduled for 19 August 2020 commenced.
Mr Matthew Williams, the defendant's senior drill and blast engineer and principal designer of the drill pattern for the blast on 20 August 2020, reported to Mr Gomez, the technical services superintendent. Mr Williams designed the drill pattern for the blast with the assistance of Mr Lee Butler, graduate mining engineer.
On or about 6 August 2020, the drilling of blast holes for the blast originally scheduled for 19 August 2020 began. On or about 16 August 2020, the drilling of blast holes for that blast ended.
The defendant contended, and I find, that it designed and implemented the blast to address difficulties it had experienced in achieving adequate fragmentation of capping rock in the previous overburden mine blast carried out on the Herndale seam on 7 August 2020.
On around 10 August 2020, Mr Lachlan May (the defendant's coal quality engineer/geologist) identified vertical cracking in the northern low wall of the Herndale area. Mr May reported his findings to Mr Williams, Mr Butler and Mr Gomez, and recommended a number of actions be taken. Mr May stated that a geotechnical inspection of the Herndale shot had been completed and made recommendations for actions to be completed before proceeding. At the time, Mr Gomez reported to Mr Moraga, the mine's general manager.
On Thursday, 13 August 2020, the inadequate fragmentation achieved by the previous blast on 7 August 2020, and the work health and safety risks it posed, were brought to the attention of Mr Gomez at a superintendent's meeting. By this time, the drilling of the blast holes for the blast was partially or substantially completed. Mr Gomez, when asked in examination in chief, guessed that "30-50% of the drill holes for the blast had already been drilled" and recollected that the blast was "half drilled".
Also on around 13 August 2020, Mr Gomez advised Dr McKenzie that "the pattern is already drilled or almost completed so there is no room to make any adjustments". As a result of the rather "late stage" of his engagement, there were limited adjustments Dr McKenzie could make to mitigate the caprock fragmentation issue. Consequently, the only design aspects that could be controlled to change the fragmentation outcome for the blast were the stemming length and timing of the charge. Dr McKenzie said that there were "not many options available any more".
[15]
Dr McKenzie gave evidence that the blast "deviated from what would be a normal standard, but the whole blast was being done differently".
Between 15 and 19 August 2020, HMS Australia Operations Pty Limited (Hanwha) mobile manufacturing units (MMUs) numbers 36, 37, 39, 42, 45, 46, 48 and 49 loaded the blast holes for the blast which was then scheduled for 19 August 2020 pursuant to load sheets which provided that 1,135 blast holes were to be loaded with explosive product. At this time, Hanwha had a supply contract with Whitehaven Coal Mining Limited (ABN 65 086 426 253), a different entity to Whitehaven Coal. Pursuant to the supply contract, the services provided by Hanwha included "Production of Explosive Products and loading down the hole [and] Providing a package including load sheets and delivery records at the completion of each blast".
Mr David Welch and Mr Bruce Willey were the shotfirers who were responsible for tying up and loading ONV_08_38_PS (shot A) and HRN_08_39_OB (shot B) respectively. Shot B is the blast the subject of the four charges in these proceedings.
According to the drill and blast design checklist, "[p]lanning pressure resulted in the need for mid-split since there was no time for a stand alone pre-split blast". Both shots A and B were tied in together so that a single initiation sequence from the centre of the pattern would detonate the shots at timed intervals. Rather than firing shot A as a standalone "pre-split blast", shot A was detonated slightly before shot B making this a "mid-split" blast.
The MMU driver loaded explosive product into the blast holes pursuant to the details on the load sheet and the identification (ID) of the blast hole. A tape with a weight on its end and knots at various lengths was used to "bob the hole"; that is, to ensure that the hole was loaded to the stem height marked on the load sheet (being 3.0m for the blast). In his record of interview dated 27 April 2021, Mr Willey explained that to record the amount of explosive product inserted into each blast hole, the MMU driver writes the number of kilograms (kg) of explosives loaded on the load sheet next to the hole ID.
An email sent from Ms Emma Bulkeley, environmental superintendent, Whitehaven Coal, to Mr Simon Lund, EPA senior investigator, dated 31 August 2020, stated that the defendant's blast design provided for 854,852kg to be loaded, that the "total dockets summary" was 896,256kg, and that there was a variance of 41,404kg (896,256kg minus 854,952kg) from the blast design.
[16]
The rescheduling of the blast scheduled for 19 August 2020 to 20 August 2020
Due to high winds, the blast originally scheduled to be carried out on 19 August 2020 at 3:30pm was rescheduled to 20 August 2020 at 10:30am, when low winds were predicted.
The Boggabri coal mine was notified in advance of the blast scheduled to take place on 20 August 2020.
[17]
"Discrepancies" noted by the shotfirer, Mr Welch
Mr Welch gave evidence that as the blast crew was tying up the shot on 19 August 2020, he noticed "discrepancies" with the timing, in that "a lot of the holes were going off very quickly, close together". He said that what one looks for in a shot is timing: "you want things to go off sequentially". He recalled that he "hadn't seen timing like that one before", and that it was "all too close". This made "[a]larm bells ring in [his] head" as "there was a lot of holes going off really close together which, when we're trained, that's not what we're trained to do". Mr Welch was "specifically concerned about "poor fragmentation" as a result of the fast timing and "environmental impact" in the form of "noise vibration" by which he meant "how loud it is and what sort of rumble it gives".
As a result, Mr Welch pulled the shot and told everyone to stop work and contacted the engineers to discuss the shot. Mr Welch recalled that he was advised by "drill and blast engineers" that "they'd done their modelling and that everything was within their boundaries", and that he responded that he "didn't quite agree" but was "open to trying new things". He further recalled that he "wasn't happy with their [the engineers'] response". After expressing his concerns to the engineers, Mr Welch recommenced tying in the shot ready to fire.
Mr Gomez ultimately decided to use 3.0m stemming and fast timing. He gave evidence that "he would have made a final decision to use fast timing after receiving the results of further modelling from Dr McKenzie in his email of 4:43pm on 18 August 2020". Mr Gomez could not recall precisely when he decided to use 3.0m stemming, although "he thought the decision would have been made about two days prior to the firing date".
[18]
The blast clearance plan
The blast clearance plan dated 20 August 2020 for blast location "HRN08-39-OB" (the blast clearance plan) shows the location of the blast rescheduled for 20 August 2020 at 10:30am relative to the exclusion zones for personnel in red (700m) and plant in yellow (500m), and blast sentries 1 to 6 in place at the time of the blast. That plan is reproduced below:
[19]
Blast monitor records for the blast on 20 August 2020
On 20 August 2020 at 10:22am, shots A and B were initiated and fired. The blast took place along part of the Herndale seam which runs through the upper benches of the mine.
In accordance with condition M7.1 of the EPL, using Ecotech Dynamaster (Ecotech) blast monitors, the defendant monitored the vibration (millimetres per second) (mm/s) levels and airblast overpressure (dBL) at the EPL monitoring points; namely, BM1 (8.3km north of the blast), BM2 (7.8km north, slightly west of the blast), BM3 (7.5km north-west of the blast) and BM4 (8.7km west, slightly south of the blast). There were also three additional dam monitors RWD, RWD2 and MWD2 located on dam walls to the northwest of the mine. This blast monitor records are summarised in the two tables below:
Vibration (mm/s)
Blast monitor Internal Model External Model Actuals
BM1 3.86 1.077 1.40
BM2 4.25 1.18 2.04
BM3 4.54 1.38 4.07
BM4 3.67 1.8 3.27
RWD - - 4.11
RWD2 - - 10.61
MWD2 - - 17.58
It was uncontroversial that the actual results of overpressure and vibration recorded at BM1, BM2, BM3 and BM4 were within the limits required under conditions L4.1 and L4.3 of the EPL.
A map depicting the approximate locations of EPL monitoring points, blast monitors at the Boggabri coal mine and at the Tarrawonga coal mine, excluding RWD, RWD2 and MWD2, and marked BM1, BM2, BM3, BM4, and TB1 (which I will refer to as the Tarrawonga monitor), TB2 (which I will refer to as the Coomalagah monitor), and on private property at Goonbri East and Wiberoi East, is reproduced below:
[22]
Mr Gomez' experience of the blast
Mr Gomez testified that because the vibration was more than he would have anticipated, he thought that the defendant had exceeded its noise limit and "was uncomfortable after that". He said that the blast "was most certainly not an ordinary blast", and that "it deviated from the standard".
[23]
Other key documents
In addition to the EPL, the EPA Act approval and the blast clearance plan, the following other key documents which were in evidence are relevant to the four charges.
[24]
The blast management plan (BLMP)
Condition 25 of the EPA Act approval required the defendant to prepare a blast management plan. WHC_PLN_MC_BLAST MANAGEMENT PLAN (the BLMP) was first prepared in May 2013, and was last updated to "Issue 2.2" in "2018" by the defendant. The prosecutor relied on the BLMP as relevant to all charges. For the timing charge, stemming length charge and overloading charge, the prosecutor alleges that the blast was not designed in a competent manner in part because it did not conform to the BLMP, in particular cl 3.3.5, resulting in a high level of noise and airblast overpressure.
The BLMP contained, inter alia, the following provisions:
Clause 1.1:
…
Land-use in the local area is dominated by agricultural operations and open cut mining with rural residential holdings mainly located to the north and west of the Project. … Various coal mines exist within close proximity to the project including Boggabri Coal Mine, Tarrawonga Coal Mine and Goonbri Exploration Lease located to the southeast of the project boundary …
Clause 1.4:
The objectives of this BMLP are to:
• Ensure that operational blast vibration and overpressure from activities associated with the MCCM are minimised;
• Maintain compliance with those conditions of the Project Approval, Environment Protection Licence 20221 (EPL 20221) and relevant legislation relating to blasting …
Clause 2.0:
2.0 STATUTORY REQUIREMENTS AND COMMITMENTS
This BLMP has been prepared to fulfil the requirements of relevant legislation, approval conditions, EPL conditions, EA commitments, and, relevant standards and guidelines.
Clause 2.3:
2.3 Environment Protection Licence
MCC is the licence holder of EPL 20221 …. The EPL 20221 conditions relevant to blasting are presented below:
L4 Blasting
…
Pursuant to cl 2.4 of the BLMP, the following guidelines and standards applied to blasting at the mine at all relevant times:
1. Australian and New Zealand Environment Council, (1990) "Technical Basis for Guidelines to Minimise Annoyance due to Blasting Overpressure and Ground Vibration" (ANZEC guidelines);
2. Australian Standard AS 2187.2-2006 "Explosives - Storage and use Part 2: Use of explosives" (the Australian Standard); and
3. the Boggabri Coal, Tarrawonga Coal and Maules Creek Coal (BTM Complex) blast management strategy.
Clause 3.1 of the BLMP provided as follows in relation to blast design:
3.1 Blast Design
Blasts will be designed to meet best management practices to ensure the blasting requirements in Schedule 3, Condition 18 and 23 of PA 10_0138 are met.
…
To ensure compliance with regulatory limits, and to minimise the likelihood of significant blast impacts to neighbouring receivers, all blast designs will consider:
…
• Expected offsite vibration levels calculated based on conservative assumptions, which will be reviewed with blast history;
…
• The adequacy of stemming and suitability of material used;
• Appropriate initiation delays and detonation systems;
…
• Blast hole loading procedures …
[25]
Australian Standard AS 2187.2-2006 "Explosives - Storage and use: Use of explosives"
Section 1.5 of the Australian Standard provided at all relevant times as follows in relation to regulatory authorities:
Explosives in each State and Territory are governed by appropriate regulatory authorities. Persons planning blasting operations should ensure compliance with the legislative requirements applicable to the activity to be undertaken …
Section 4 provided relevantly in relation to plannin":
SECTION 4 PLANNING
4.1 GENERAL PROVISIONS
All blasts whether surface, underground or submarine, shall be planned and designed to achieve the required outcome with first considerations being the protection of persons, property and the environment.
Before the commencement of any blasting operation an investigation of the site and its environs, or the item to be blasted shall be carried out identifying any potential hazards/risks. On the basis of the investigation, a blast management plan incorporating a risk assessment and control of measures shall be prepared.
4.2 BLAST MANAGEMENT PLAN
There shall be an overall blast management plan in accordance with Appendix A. Records should be maintained. No blasting shall commence until a competent person has authorized the blast management plan.
…
4.8 ENVIRONMENTAL IMPACTS
The area surrounding the blast site should be inspected and assessed to determine appropriate means of minimizing environmental impacts. Regulatory limits may apply.
In conducting the risk management, foreseeable factors should be considered, including, but not limited to the following:
(a) Distances to buildings, structures, and other environmental effects.
Note: See Appendix J for guidance.
…
(c) Ground vibration and airblast overpressure.
…
(e) Effects of dust, fume, sediment run-off, noise.
…
4.10 SPECIAL PRECAUTIONS
Due to the many environments in which blasting takes place, not all hazards can be identified and raised in this document.
The onus is on the entities undertaking blasting activities to use this document, and specialist experience within the blasting operation they are undertaking, to manage risks associated with the blasting activity. It is foreseeable that every blasting operation will have specific and special precautions that need to be implemented for the safety and health of persons, property and environment.
4.11 BLAST DESIGN
…
The blast management plan shall outline the objective of the blast. The objectives may including the following:
(a) Fragmentation.
(b) Movement.
(c) Environmental considerations.
(d) Preservation of the stability of adjacent rock.
(e) Minimization of back-break/over-break.
…
[26]
*A sensitive site includes houses and low rise buildings, theatres, schools, and other similar buildings occupied by people.
NOTE: The recommendations in Table J4.5(A) are intended to be informative and do not override statutory requirements with respect to human comfort limits set by various authorities. They should be read in conjunction with any such statutory requirements and with regard to their respective jurisdictions.
Section J5.1 of Appendix J to the Australian Standard provides relevantly in relation to airblast levels:
Airblast can cause discomfort to persons and, at high levels, damages to structures and architectural elements, and a very high levels, injury to persons. …
Section J5.4 of Appendix J to the Australian Standard provides in relation to recommended airblast limits:
Airblast limits for human comfort chosen by some regulatory authorities are provided in Table J5.4(A). Recommended damage control limits are given in Table 5.4(B). All the limits are expressed as peak linear sound pressure levels. …
Table J5.4(A) provides in relation to airblast limits for human comfort chosen by some regulatory authorities:
AIRBLAST LIMITS FOR HUMAN COMFORT CHOSEN BY SOME REGULATORY AGENCIES (See Note to Table J5.4(B))
Category Type of blasting operations Peak sound pressure level (dBL)
Human comfort levels
Sensitive site* Operations lasting longer than 12 months or more than 20 blasts 115dBL for 95% blast per year. 120dBL maximum unless agreement is reached with occupier …
Sensitive site* Operations lasting for less than 12 months or less than 20 blasts 120dBL mm/s for 95% blasts. 125dBL maximum unless agreement is reached with occupier …
Occupied non-sensitive sites, such as factories and commercial premises All blasting 125dBL maximum …
[27]
*A sensitive site includes houses and low rise residential buildings, hospitals, schools, etc., occupied by people.
Table J5.4(B) provides relevantly in relation to recommended airblast limits for damage control:
RECOMMENDED AIRBLAST LIMITS FOR DAMAGE CONTROL (see Note)
…
NOTE: Tables J5.4(A) and J5.4(B) are intended to be informative and do not override statutory requirements, particularly with respect to human comfort levels set by various authorities. They should be read in conjunction with any such statutory requirements and with regard to their respective jurisdiction.
[28]
Whitehaven Coal procedures
The prosecutor submitted, and I find established beyond reasonable doubt, that at all relevant times the following Whitehaven Coal procedures applied to blasting activities at the mine:
1. WHC-PRO-OC-Planning, Design and Record Keeping (the planning, design and record keeping procedure); and
2. WHC-PRO-OC-Loading and Stemming Blast Holes (the loading and stemming blast holes procedure).
[29]
The planning, design and record keeping procedure
Prior to the period of the alleged offences, the planning, design and record keeping procedure was last revised on 10 April 2018. The prosecutor submitted that the planning, design and record keeping procedure refers to a design standard which prescribes the parameters for a standard fixed pattern for blasting. The prosecutor submitted, and I find, that at all relevant times the design standard applied to blasting at the mine.
Section 1 of the planning, design and record keeping procedure states that the "objective of controlled blast design is to enable safe blasting of overburden and coal, while ensuring suitable fragmentation and muckpile profile to match the chosen digging equipment whilst remaining within the environmental limits set for the mine". Section 3.2.2 provided as follows in relation to the design standard:
○ Once the Design Inputs have been documented and reviewed the drill and blast engineer shall select an appropriate Approved Design Standard.
APPROVED DESIGN STANDARD
○ Once an appropriate Approved Design Standard .pdf has been selected it is to be used to complete the drill pattern being designed.
…
■ The design objective is to deliver a drill pattern design within 10% of the target design parameters.
[30]
The loading and stemming blast holes procedure
The loading and stemming blast holes procedure was last revised on 15 May 2018 prior to the period of the alleged offences. The scope was to "control blast hole charging and stemming operations, and related activities". It applied "to all loading and stemming operations including dewatering, priming blast holes, loading of bulk explosives, the placement of any non-explosive blast hole products such as stemming and gas bags, and the removal of stemming and/or explosives with the vacuum truck".
Section 3.2 provided in relation to blast hole layout:
It is essential that blast holes are primed and charged in accordance with design standards, and to suit any variation in site conditions (depth, water content etc).
A blast hole shall only be charged if it has been checked for adequate burden, depth, inclination, cracks and obstructions and it is not knowingly within 1m of a drill hole butt.
Holes will be identified on the ground (and on the plan) to record special conditions and requirements including ... [o]verloaded holes …
Section 3.5 provided in relation to bulk charging and stemming:
Load sheets specify the design kg and the maximum kg. The maximum kg may only be exceeded by direction instruction from the shotfirer.
[31]
The design standard
The prosecutor also relied on the design standard. The design standard identified the loading parameters, stemming as 3.5m, the relevant seam at the mine as "HRN", meaning Herndale, and the type as "Overburden".
[32]
The drill and blast design checklist
The two page drill and blast design checklist, dated 4 August 2020, is extracted below:
The drill and blast design checklist identifies the pattern name for the blast as "HRN_08_39_OB", and the design as by "Matt Williams". The authorised design standard is identified as "ST_HRN_229_OB_D_V1". The seam is "Herndale", and the type is "Overburden".
In the drill and blast design checklist, the question "have the design parameters as specified in the Approved Design Standard been modified" is answered "Yes", and "Stemming reduced to 3m". The Timing Path is identified as "CentreLift", and "Timing designed in consultation with blasting consultant".
[33]
Blast hazard analysis
The WHC_CHK_OC_MC_Environmental Blast Hazard Analysis (the blast hazard analysis) for the blast is reproduced below (with highlights in the original document):
[34]
International Society of Explosives Engineers Blasters' Handbook
Dr Cameron (the expert called by the prosecutor) annexed to his further supplementary opinion dated 9 December 2022 extracts from the International Society of Explosives Engineers Blasters' Handbook (ISEE Blasters' Handbook), [3] relevantly sections of chapter 9 "Fragmentation and Heave Process", chapter 11 "Explosives Properties and Performance Characteristics", and chapter 33 "Surface Blasting". In his report dated 4 November 2021, Dr Cameron referred to the following "rule of thumb" in the ISEE Blasters' Handbook in relation to stemming length:
A Rule of Thumb commonly used for calculating stemming length from ISEE Blaster's Handbook (18th edition) and Orica's Pocket Blast Guide is stemming length = 20-30 times blasthole diameter. Applying this Rule of Thumb, 20 times the blasthole diameter of 0.229m for blast HRN_08_39_OB is approximately 4.6m. This indicates that the Approved Standard Design stemming length of 3.5m (15.3 x blasthole diameter) is already less than that normally used and, therefore, a further reduction of this length by 14% is a significant amount.
In summary, the rule of thumb is that the stemming length should be between 20 and 30 times the blast hole diameter (referred to herein after as the blast ratio).
Dr Aimone-Martin (the expert called by the defendant) also referred to the ISEE Blasters' Handbook in her report dated 10 October 2022 in relation to the overloading charge, saying that the ISEE Blasters' Handbook "does not provide a clear definition of overloaded blast holes but rather describes the consequences of overloading holes …". This includes "excessive flyrock, or rock that is propelling laterally beyond the blast area as defined by the lead blaster, and high ground vibrations". Dr Aimone-Martin referred to chapter 9 and the following paragraph on "Rock Movement":
A distinct but short time delay occurs between detonation of the borehole and the initial detectable movement of the bench face or top surface … However, if the blast is designed with too little burden or stemming and/or too high of a powder factor, premature movement of the rock can release explosive energy in the form of jetting gases …
[35]
Lewandowski reports
Mr Thomas Lewandowski of Enviro Strata Consulting Pty Ltd prepared a report titled "Assessment of Blasting Impacts for the Blasts Fired on 20.08.20" dated 29 August 2020 (the first Lewandowski report), and a report titled "Review of Meteorological Constraints Relative to the Overpressure Hazard When Blasting at Maules Creek Coal" dated 21 January 2021 (the second Lewandowski report) (the Lewandowski reports). The reports were prepared for the defendant in response to an inquiry by the NSW Department of Planning, Industry and Environment following complaints lodged with the Department by local residents. Both reports discussed wind speeds and directions as at the date of the blast. The reports analysed airblast overpressure and ground vibration results such as wavetrace records from BM1, BM2, BM3, BM4, RWD2 and MWD2, the blast design details and video records. The reports also reviewed wavetrace records from the Tarrawonga monitor (located to the south of the mine) and the Coomalagah monitor (located to the south-east of the mine, approximately 12.5km from the blast).
The first Lewandowski report included the following figure, figure 2A, in relation to wind speed at the Maules Creek weather station before, during and after the blast:
The defendant raised the issue of weight to be given to the Lewandowski reports in relation to the emission of noise charge as they were untested. The prosecutor's response was as follows:
HER HONOUR: … the defendant makes a valid point in relation to the weight that the Court would attach to untested evidence contained in the Lewandowski reports, notwithstanding they are documents of the defendant in circumstances where there was no opportunity for that material to be tested in any way by the defendant or - and the prosecutor didn't put on any of its own evidence in relation to those matters. What do you say about that?
LEGGAT: It's a good point. It's not determinative your Honour may be satisfied that where there was an agreement between Dr Aimone-Martin and Mr Lewandowski about the underlying assumptions, the wind speeds and the directions and matters like that, coupled with Dr Aimone-Martin's concession that the blast management plan deals with an under six kilometres an hour wind as being in a green category. That is a category where one can fire without having to think about whether at all and where this wind is agreed to be well and truly in the green category that the impact of site is an impact that is not explained or defended by there being unusual weather patterns because the speed and direction of the wind was in the under six kilometres an hour green category which was the expectation.
… There are two propositions there. The first is that even if the wind speed was such as to explain the contravention at the sensitive site at Coomalagah that was an event that ought to have caused the defendant to not fire the charge if there was likely to be that consequence because of the wind, then that means that the blast should have been postponed for another day.
You'll recall that it was originally scheduled for the 19th and the weather conditions, or the atmospheric conditions were such that the blast couldn't proceed on that day. They waited until the conditions were better and Dr Aimone-Martin would contend that whilst they may have been better, they were still unusual and provide an explanation as to why there was the non-compliance of that sensitive location. So our proposition is that if the weather conditions were unusual, then the blast should have been called off. And that's in answer to Dr Aimone-Martin's logics.
I'm not seeking to go outside of the particulars in the summons. I am simply taking the opportunity to respond to your Honour's observation that Dr Aimone-Martin has called in aid as part of her reasoning process the unusual reading, the non-compliant reading. And the other point is that you wouldn't be satisfied that the weather was unusual because Dr Aimone-Martin's acceptance of the relevant wind speed and direction put both of those factors into the green category where no precautions were needed to be taken. And in such circumstances, it borders on self-evident that one's not dealing with unusual atmospheric conditions when the atmospheric conditions are within the green category …
[36]
Relevant statutory provisions
Section 3 of the POEO Act identifies the objects of the Act as including relevantly those in (a) and (d)(i), (ii) and (iv):
3 Objects of Act
The objects of this Act are as follows -
(a) to protect, restore and enhance the quality of the environment in New South Wales, having regard to the need to maintain ecologically sustainable development,
…
(d) to reduce risks to human health and prevent the degradation of the environment by the use of mechanisms that promote the following -
(i) pollution prevention and cleaner production,
(ii) the reduction to harmless levels of the discharge of substances likely to cause harm to the environment,
…
(iv) the making of progressive environmental improvements, including the reduction of pollution at source,
…
Each of the timing charge, the stemming length charge and the overloading charge alleges a breach of s 64(1) of the POEO Act. As at the date of the alleged offences, s 64 of the POEO Act provided relevantly as follows:
64 Failure to comply with condition
(1) Offence If any condition of a licence is contravened by any person, each holder of the licence is guilty of an offence.
Maximum penalty -
(a) in the case of a corporation - $1,000,000 and, in the case of a continuing offence, a further penalty of $120,000 for each day the offence continues, or
(b) in the case of an individual - $250,000 and, in the case of a continuing offence, a further penalty of $60,000 for each day the offence continues.
Note -
An offence against subsection (1) committed by a corporation is an offence attracting special executive liability for a director or other person involved in the management of the corporation - see section 169.
(2) Defence The holder of a licence is not guilty of an offence against this section if the holder establishes that -
(a) the contravention of the condition was caused by another person, and
(b) that other person was not associated with the holder at the time the condition was contravened, and
(c) the holder took all reasonable steps to prevent the contravention of the condition.
A person is associated with the holder for the purposes of paragraph (b) (but without limiting any other circumstances of association) if the person is an employee, agent, licensee, contractor or sub-contractor of the holder.
…
The emission of noise charge alleges a breach of s 140(1) of the POEO Act. As at the date of the alleged offence, s 140 of the POEO Act provided as follows:
140 Dealing with materials
(1) The occupier of any premises who deals with materials in or on premises in such a manner as to cause the emission of noise from those premises is guilty of an offence if the noise so caused, or any part of it, is caused by the occupier's failure to deal with those materials in a proper and efficient manner.
(2) In this section -
deal with materials means process, handle, move, store or dispose of the materials.
materials includes raw materials, materials in the process of manufacture, manufactured materials, by-products, or waste materials.
[37]
Separate consideration of the four charges
Although the four charges were heard together, the Court must consider the charges separately. In Environment Protection Authority v O'Brien (EPA v O'Brien), [4] Robson J said at [110] that "it would be impermissible to reason that if the prosecutor provided that [the defendant] committed one offence, he must necessarily have committed another, or the others", citing R v Filiopovic; R v Gelevski [5] at [127] (Curtain AJA). Robson J said at [110]: "in circumstances where the prosecutor has relied upon one body of evidence in respect of the charges, I may nevertheless, in reaching my verdict(s), consider the totality of the evidence in the case as relevant to each charge", referring to Sutton v R (Brennan J). [6]
[38]
Burden and standard of proof
For each charge, the prosecutor bears the onus of proof to establish the guilt of the defendant beyond reasonable doubt. As Robson J said in EPA v O'Brien at [111]: "the prosecutor is not, however, required to prove the truth and reliability of every disputed fact, or to answer every question that might be posed concerning the evidence of the case".
[39]
Strict liability
Section 64(1) of the POEO Act creates a strict liability offence: Environment Protection Authority v Sydney Water Corporation [7] (EPA v Sydney Water (Pain J)) at [2] (Pain J).
In closing submissions, the defendant agreed that s 64(1) is a "strict liability offence in its terms", however submitted that this "doesn't end the enquiry as to whether there's a mental element or … fault element required to be proved in proof of the subject charges". The defendant contended that the inquiry "must also be directed to the elements of condition O1.1 [of the EPL]", and that condition O1.1 "does include a mental or fault element, namely incompetence or a lack of competence in the manner of carrying out a licensed activity". The defendant submitted that the prosecutor "missed" this point as it did not address the question of competence as a mental element of the offence. This issue is further ventilated below at [349]-[354].
Likewise, s 140(1) of the POEO Act creates a strict liability offence.
[40]
Witnesses and fact finding
As Robson J said in EPA v O'Brien at [129], I am entitled to accept part of a witness's evidence and reject other parts. In Fox v Percy, [8] Gleeson CJ, Gummow and Kirby JJ at [31] observed as follows:
… in recent years, judges have become more aware of scientific research that has cast doubt on the ability of judges (or anyone else) to tell truth from falsehood accurately on the basis of such appearances. Considerations such as these have encouraged judges … to limit their reliance on the appearances of witnesses and to reason to their conclusions, as far as possible, on the basis of contemporary materials, objectively established facts and the apparent logic of events. This does not eliminate the established principles about witness credibility; but it tends to reduce the occasions where those principles are seen as critical.
[41]
Prosecutor's evidence
The prosecutor read the following affidavits (parts of which were subject to objections by the defendant and rulings):
1. Ms Lynette Eileen Louis, local resident, dated 6 July 2021;
2. Ms Roselyn Druce, local resident, dated 8 July 2021;
3. Mr Ross Winton Kereopa, local resident and also operator at the Boggabri coal mine, dated 15 July 2021;
4. Ms Christine Jane Westlake, operator at the Boggabri coal mine, dated 15 July 2021;
5. Mr Jonathon James Byrnes, operator at the Boggabri coal mine, dated 27 July 2021;
6. Ms Rebecca Severin, operator at the Boggabri coal mine, dated 2 August 2021;
7. Mr Simon Kenneth Lund, EPA senior investigator, dated 13 August 2021, (and exhibit SL-1);
8. three affidavits of Dr Alan Cameron, the prosecutor's expert witness:
1. dated 4 November 2021 annexing his report titled "Investigation of Blast at Maules Creek Coal Mine" dated 4 November 2021 (Dr Cameron's report dated 4 November 2021);
2. dated 9 December 2022 annexing his supplementary report titled "Supplementary Expert Report of Alan Cameron" dated 24 May 2022 (Dr Cameron's supplementary report dated 24 May 2022); and
3. dated 9 December 2022 annexing his further supplementary opinion dated 9 December 2022 (Dr Cameron's supplementary opinion dated 9 December 2022).
1. Ms Jasmine Rose Walden, EPA investigator and authorised officer, dated 25 May 2022.
In addition, the prosecutor's evidence which was not the subject of objection or which I determined to admit over objections of the defendant was the following:
1. the SOAF filed on 2 December 2022;
2. two files of video recording the record of interview conducted on 24 May 2021 between the EPA and Dr McKenzie (the blasting consultant engaged by the defendant) and exhibits referred to in the record of interview;
3. transcripts of records of interview, including:
1. the interview between the EPA and Dr McKenzie conducted on 24 May 2021; and
2. supplementary record of interview transcripts and index of documents shown to Dr McKenzie, Mr Jorge Moraga (general manager employed by the defendant at the mine at all relevant times), Ms Bulkeley, Mr Bruce Willey (shotfirer at the mine at all relevant times) and Mr Lee Butler (graduate mining engineer employed at the mine at all relevant times);
1. documents shown to witnesses during examination in chief or cross-examination during the course of the hearing between 30 January and 3 February, 6 and 10 February, 18 and 21 September, and 13 and 16 November 2023, including:
1. specific pages of the transcript of the Microsoft Teams recording identified in the schedule in response to "item 9" of the call attended by Mr Byrnes, Ms Walden and Mr Lund dated 12 January 2021, and relevant pages of Mr Lund's EPA investigation notebook;
2. the index of documents shown to Mr Gomez by the prosecutor during examination in chief;
3. the index of documents shown to Mr Williams by the prosecutor during examination in chief;
4. the index of documents shown to Mr Welch by the prosecutor during examination in chief, the documents titled "Shotfirers Daily Report #8860" and "Load Sheet "BP0267"", and the videos titled "Video of the Shot/Blast" and "Video of the Shot Taken by Drone";
5. a letter from Mr Andrew J O'Halloran of R J O'Halloran & Co to Ms Ellie Chapman of the EPA dated 23 July 2021, shown to Mr Byrnes by the defendant in cross-examination; and
6. a hypothetical - overloaded / unloaded holes diagram shown to Dr Aimone-Martin by the prosecutor in cross-examination (extracted below at [236]);
1. pressed sections of the supplementary report of the prosecutor's expert Dr Cameron dated 24 May 2022;
2. the annexure to the email from Mr Williams to Dr McKenzie sent 14 August 2020 at 11:34am, being the "drill map and design csv [comma-separated values file] for the HRN_08_39_OB shot as currently sits";
3. a screen capture from the program used to design the blasts which shows the design blast holes and triangulation representing the face scan that Mr Williams showed EPA investigator Mr Lund in his record of interview on 27 April 2021;
4. the go-line and crib hut at the Boggabri coal mine marked up by Mr Byrnes in cross-examination on 18 September 2023;
5. two tabs of exhibit JW-1 to the affidavit of Ms Walden, dated 25 May 2022;
6. pages from exhibit SL-1 to the affidavit of Mr Lund, dated 13 August 2021; and
7. the ASIC extract of the defendant dated 17 August 2021, the notice of modification of the EPA Act approval under s 75W of the EPA Act dated 10 March 2014, the ANZEC guidelines, and the Australian Standard.
[42]
Defendant's evidence
The defendant relied on the report of Dr Aimone-Martin annexed to her affidavit dated 31 October 2022 and titled "Responses to five charges made against Maules Creek Coal Pty Limited (MCC) relating to EPA v Maules Creek Coal Pty Limited Proceedings 2021/234554-234558 Proceedings arising from Blast Event on 20 August 2020" dated 10 October 2022 (Dr Aimone-Martin's report dated 10 October 2022).
The defendant also tendered the "Blast Management Strategy for Boggabri -Tarrawonga - Maules Creek Complex" dated April 2020 (the blast management strategy).
[43]
Evidence of lay witnesses
Dr McKenzie, Mr Gomez, Mr Williams, Mr Welch, Mr Moraga, Ms Druce, Mr Byrnes, Ms Severin, Ms Walden and Mr Lund provided oral evidence pursuant to subpoenas to attend, and were examined by the prosecutor.
[44]
Dr Cameron McKenzie
Dr McKenzie was the blasting consultant engaged by the defendant at all relevant times. Dr McKenzie's examination in chief consisted of his record of interview dated 24 May 2021 with Mr Lund, Ms Walden and Ms Samantha Daly (lawyer). In closing oral submissions, the Court asked the defendant how it should deal with Dr McKenzie's evidence given that he had not been qualified as an expert in the proceedings. Mr Howard SC for the defendant said as follows:
I'm not asking your Honour to accept his evidence as expert evidence, what I'm asking your Honour to consider is his expertise in relation to the matters at the time. He hasn't been qualified as an expert in the proceedings and he's not put forward as such, but he is called as a witness because he was the expert who designed the blast. That's why he was interviewed by the Environment Protection Authority, that's why he was retained by Maules Creek Coal, and of course your Honour, with respect, would certainly take into account on the question of whether Maules Creek Coal carried out the blast in a competent manner. The fact that it engaged a highly accredited expert to deal with the very matter that's the subject of the complaint, and was guided by his advice.
In his record of interview dated 24 May 2021, Dr McKenzie said as follows in relation to his initial engagement by the mine's general manager, Mr Moraga:
A … Jorge mentioned to me in the telephone conversation [on 18 November 2019], and for that matter again when I was on site that he was very concerned about the effect of the poor, or the very coarse fragmentation which was occurring in the uppermost section of their benches on the safety of the shovel operators, in that when they attempt to handle large rock blocks, if that block moves in the bucket, then it severely jolts the operator and can lead to back injuries. So, he was concerned that the fragmentation was placing the health and wellbeing of his operators at risk.
In relation to the late stage at which he was involved with the design of the blast, Dr McKenzie said as follows in re-examination (emphasis added):
Q. Did you discuss with someone that this was a rather late stage for you to be involved?
A. I probably did, that - yes, that there were not many options available anymore, yeah.
Q. Do you know whether that concept of this "rather late stage" was introduced by yourself or was that introduced by someone from the mine?
A. Look, it could have been either way or it could have been both ways. I mean I … recall asking them if they had implemented any of the recommendations in my first report [dated December 2019] and my response to that was, "No", but when you think about it, there was - other than the satellite or the stamp hole drilling, there wasn't anything they could have done, except six and 12 months beforehand, by pre-drilling or pre-conditioning that scene.
[45]
Mr Ryan Gomez
In relation to the superintendent's meeting he attended on or around 13 or 14 August 2020 at about 8:30am (which I have previously found to have occurred on Thursday, 13 August 2020), Mr Gomez (the technical services supervisor at the mine) gave the following evidence in examination in chief concerning discussion of the issue of caprock:
A. … I clearly remember that meeting. So it was a morning superintendent's meeting where we discuss performance of the previous 24 hours and any issues in the next 24 hours. … there was the issue of cap rock for the adjacent Herndale blast … he said that, "Look, they're having some issues with loading those big rocks, the cap rock, under the back of the trucks and, you know, obviously hurting people. So we need to do something different so that that doesn't happen in the adjacent blast and we do not hurt anyone."
…
A. … I was aware of the cap rock at that meeting. I have no recollection of cap rock prior to that meeting.
Mr Gomez gave evidence (in examination in chief) that he authorised Mr Williams to send an email to Dr McKenzie after the superintendent's meeting on 13 August 2020. In relation to what he discussed with Dr McKenzie in the phone call at 5:08pm on 14 August 2020, Mr Gomez' evidence in examination in chief was as follows:
A. … it was around varying the stemming length, reducing the stemming length and probably increasing the, increase the timing or do something different to our traditional timing for us to kind of address that caprock issue …
A. … the main intent of us to do that modelling was to make sure we don't hurt anyone and be in an environmental compliant …
In relation to the instructions he gave Dr McKenzie to be conservative in his modelling, Mr Gomez said in examination in chief (emphasis added):
A. … my recollection is that we got the results of the modelling initially and we're modelling to, from memory, it was 119 decibel. Looking at those results and the wording that [Dr McKenzie] … spent some time, you know, depressing and thinking about the, the results at 119 decibel being reliable, we landed on making that cut-off limit more conservative.
… rather than modelling to 119 decibel, we said, look, let's go and model to 114 decibel. I think it was 114 from memory. …
A. … in that last paragraph in the email, so after he sent the initial email, which we modelled [119] decibel, we said we need to go back and model to a more conservative number, 115 decibel, and then what Cameron actually asked for was an old - an old shot, an old blast and what the readings were for that blast. So somewhere in between what we got Cameron to do, to check if this modelling is actually accurate, simulate another blast and see what the readings were for that blast and the outcome from his modelling was that his modelling was 2 decibel over the actuals, from memory.
So there was two layers of conservatism. One is we dropped the 119 decibel to 115 decibel and the second control was we looked … at this modelling because he says his modelling, you know, the distances aren't reliable. So we looked at another blast and … his results against the actuals and his results were higher than the actuals. So we - the thinking there was, whatever his modelling now, it is going to be 2 decibels higher than what you would expect. …
Q. I just want to clarify one thing. You identified a level of 114 dB as being a more conservative level and then you also identified a level of 115 dB as being a more conservative level. Can you recall, from your best recollection, as to whether it was 114 or 115 discussed, or perhaps it may have even been both of them, with Dr McKenzie?
A. Look, I think it was 114, but I can't put my hand on my heart and say that was the number, it's been that long ago, but I think it was 114.
[46]
Mr Matthew Williams
Mr Williams, the defendant's senior drill and blast expert, gave the following evidence in examination in chief in relation to the previous blast on 7 August 2020 and his email to Dr McKenzie, copied to Mr Gomez, at 9:40am on 14 August 2020:
A. It would've been with discussions from probably Ryan [Gomez], maybe others. Just making it aware and conveying, sort of, the importance that we've had the issue with caprock in the previous blast and that we needed to try to change something or rectify that for the next blast and that I should reach out to Cameron [McKenzie] for help with that.
[47]
Mr David Welch
Mr Welch, one of the shotfirers responsible for loading and tying up shots A and B, testified as follows (in examination in chief) in relation to his concerns about timing (emphasis added):
… what we look for in a shot is timing. … you want things to go off sequentially and it, it looked like it was all too close, you know. Alarm bells ring in your head if you've got two holes going off at the same time, let alone close together. So, yeah, I hadn't seen timing like that one before.
Q. In terms of the timing being all too close, can you provide a little bit more information as to what you mean by "All too close"?
A. If I remember correctly, again, I think there was, like, one to three milliseconds between holes going off across the shot. There was two initiation points, if I remember correctly again, centre diamond lift and the, yeah, there was a lot of holes going off really close together which, when we're trained, that's not what we're trained to do.
In relation to his concerns as at Wednesday, 19 August 2020 concerning noise vibration, the evidence of Mr Welch was:
Q. As at 19 August [2020], what consequences were you concerned about because the timing was, in your view, way too quick?
A. I was concerned about poor fragmentation. … I was also concerned about, you know, environmental impact.
Q. When you say "environmental impact", what do you mean by that?
A. Noise vibration.
Q. When you say "noise vibration", what do you mean by that?
A. How loud it is and what sort of rumble it gives, I suppose.
In relation to the events of 19 August 2020, Mr Welch testified (emphasis added):
A. Okay, that was a really long time ago for me. I think we went down to tie in the shot and I think we started tying it in; we came up at a few discrepancies that was talked with the engineers I believe about timing.
Q. When you say "we", as at the Wednesday 19 who do you mean by "we"?
A. That'd be the blast crew.
Q. You use the word "discrepancies"; can you provide a bit more information about what you mean by discrepancies, please?
A. If I remember correctly, what, what we're trained as shotfirers to do is make sure that the timing is all sequential. So while we were tying it in, I think we discovered that a lot of the holes were going off very quickly, close together. So I believe we raised concerns and then ran it up the chain to see whether, you know, it's all true and accurate and that's what they wanted us to do.
If remember correctly, I think may have pulled the shot up and told everyone to stop work cause I wasn't entirely happy with the timing, and I think, I think I went and had discussions with the engineers. I think I drove off the shot and went and had discussions.
…
A. I, I really can't remember exactly what I said or who, or who exactly I spoke to. It was the engineers, I do remember that cause I remember going up cause I wasn't happy with their response; I went up and had a conversation with them.
…
A. If I remember correctly, I raised concerns about the quickness of the timing of the entire shot. I said holes were going off together. I believe they said they'd done their modelling and that everything was within their boundaries, something along those terms, and I think I said I didn't quite agree but I'm open to trying new things; they said they'd tried it in other countries on another mine site. So, you know, if you, if you don't live and learn, you don't live, so I gave it a crack after that I think.
…
Q. After you expressed your concerns, what happened next?
A. … they ran me through everything and they said it was within the parameters, I think I went back and continued tying it in.
…
A. … I went back down and opened the shot back up, got the crew running and tied it in ready to fire.
[48]
Mr Jorge Moraga
In his record of interview, Mr Moraga, the mine's general manager, provided the following evidence in relation to the previous blast and the drill and blast design process at the mine:
A. But you know, we have all the processes and procedures, our plans. So, the people have already predefined some areas with different, how you, standards to apply.
…
A. … One week, we have in that particular place was a big layer of conglomerate. We couldn't blast better than in the previous shot. So, we had big boulders, bigger than this room that was causing so much damage to our equipment, and also potential injuries to our people.
...
A. So that was one of the triggers to review that particular blast. To improve that particular fragmentation and to have a safe place to mine really …
In relation to the number of workers at the mine on 20 August 2020 and their location, Mr Moraga testified that there were "approx. (as said) 450, 420 people", and that the closest distance that any of the workers at the mine were to the blast was 700m, and that the furthest person at the mine was "1.5 maybe, approx, kilometre".
Mr Moraga testified that none of the mine's workers reported discomfort on 20 August 2020 following the blast.
[49]
Mr Jonathon Byrnes
In his affidavit dated 27 July 2021, Mr Byrnes, an operator at the Boggabri coal mine at the date of the blast, deposed that "at about 1020 hours on Thursday 20 August 2020, I was present at the go line at Boggabri Coal Mine … As I was walking across the go-line I pulled my ear plugs out and I heard this almighty pop, like a gun shot going off right next to my head". Mr Byrnes said that he "felt a shake in the ground … looked over and …. saw a blast had gone off at [the mine]". Mr Byrnes said: "[i]mmediately after the blast, I felt pressure in my ear. This lasted for 3 or 4 seconds. After that I had ringing in my ears". Mr Byrnes said he "went to see the First Aid Staff … [Ms Severin] and I were then taken into Boggabri Hospital for assessment". Mr Byrnes deposed that at Boggabri Hospital he "did not have a burst ear drum". Mr Byrnes said that on 29 September 2020, he completed a worker's injury claim form with "Coal Mines Insurance".
Mr Byrnes deposed that on 9 December 2020, he attended Boggabri Medical Centre. He was experiencing difficulty sleeping and was placed on sleeping tablets as a consequence of the constant ringing in his ears. Mr Byrnes said: "I have been left constant ringing in both my left and right ears … I have been advised that the high-pitched ringing is known as tinnitus … I have had three terrible ear infections since August 2020". Mr Byrnes deposed that "[p]rior to the ringing … I was sleeping on average 7-8 hours per night. I am now … probably getting 3-4 hours of sleep … My moods also fluctuate and I continue to have the odd nightmare about the explosion".
In cross-examination, Mr Byrnes accepted that he had filed a statement of claim against the defendant arising out of the blast on 20 August 2020.
[50]
Ms Rebecca Severin
Ms Rebecca Severin, also an operator at the Boggabri coal mine at the date of the blast deposed in her affidavit dated 2 August 2021 that on 20 August 2020, she was working at the Boggabri coal mine, and was sitting outside the crib hut when she heard the first explosion: "A second later I heard a second blast". Ms Severin deposed that "[t]he pain was immediate, and I instantly grabbed my ear". Ms Severin said that "the blast I heard on 20 August 2020 was different to anything I had experienced before. This one was so loud and shook the ground" (emphasis added).
Ms Severin deposed that she went to the Emergency Response Team and said that "I was worried about my ear drum as it felt like fluid was leaking out of the right ear … I then went to Boggabri Hospital for a check of my ears". Ms Severin said that she was "advised by hospital medical staff to see a hearing specialist to make sure there was no permanent damage". Ms Severin attended the hearing specialist and was told that her hearing was fine, "but that did not exclude me suffering damage later on and to keep an eye on it".
In cross-examination, Ms Severin gave the following evidence about the number of people working at the Boggabri coal mine on 20 August 2020:
A. … there's about a hundred, at least a hundred. I would say in the whole mine, maybe 150, 160.
Q. If a figure of around 400 was suggested to you, would agree to that?
A. I suppose including all the staff and that weren't actually down in the pit?
In relation to the first contact she had with anyone from the EPA in relation to the blast, Ms Severin testified that this was after she had the hearing test done, and that "it wasn't that long after … September, October maybe". She said that the hearing test was done "in a hearing specialist in Tamworth".
In relation to her communications with Mr Byrnes before she signed her affidavit, Ms Severin said:
Q. … before you signed your affidavit, did you speak to Mr [Byrnes] about what his recollection was about what happened at the blast?
A. … It was pretty much what I thought, the same thing, it was very loud, and extremely different to the normal blasts and I said my ear was hurting and he had stated his was, too.
…
Q. Was one of the reasons for speaking to Mr [Byrnes], to make sure your recollections were the same about what happened at the time of the blasts, before either of you did a statement?
A. No, that's not correct. I didn't speak to him just to confirm my recollection. I knew what mine was.
[51]
Ms Roselyn Druce
On 20 August 2020, Ms Druce, a local resident, made a complaint to the environment line of the EPA about the blast that had occurred that morning. She deposed that she lives "approximately 7 kilometres from the [mine]" and that at about 10:20am on 20 August 2020 she was at her property, and the "lounge chair [she] was sitting in started shaking from side to side". Her "first thought was that there had been an earthquake". Ms Druce deposed that "I've never felt that much vibration from underground from a blast before. This time, it was a real ground vibration".
Ms Druce gave the following evidence in relation to her opposition to the mine:
Q. In December 2013, were you one of the group of protestors who sought to stop work on the Maules Creek Mine, blockading three entrances to the site?
A. I was one of the conservationists, yes.
Q. Did you write an opinion piece in January 2014 about the Maules Creek Mine?
A. You are stretching my memory now, but possibly.
Q. Do you remember writing an article online for The Northern Daily Leader in January 2014 about the Maules Creek Mine?
A. Unless I read it, I, I couldn't tell you.
Q. Do you remember saying words to the following effect, publishing them in an online article, "It's about time people understand why all this activist action has been taking place in and around the Leard State Forest"?
A. Yes. I remember doing that.
…
Q. It is fair to say, isn't it, that in period 2013 to 2014 you were a member of the local community vehemently opposed to the Maules Creek Mine? Is that true?
A. Well, I'm a Maules Creek community member that, that grew up and lived there, yes, and, yes, they were destroying the Leard State Forest, so I was very concerned about the conservation value of the, the fauna and flora that was being destroyed, yes.
Q. … ever since 2014 before the mine was actually constructed you have been opposed to its construction and operation in its location? Is that fair?
A. Yes.
…
Q. I want to suggest to you that given your longstanding opposition to the Maules Creek mine as at 20 August 2020, and given the effluxion of time before you swore your affidavit, that the actual words you chose could contain some subjective element about your perception that did not necessarily accord with what you felt at the time, is that possible?
A. … I find that quite offensive. No, I, I don't believe that's correct.
[52]
Ms Christine Westlake
In her affidavit dated 15 July 2021, Ms Westlake, operator at the Boggabri coal mine, deposed that her "property is located approximately 12 kilometres [e]ast of the [mine]", and that "[a]t about mid-morning on 20 August 2020 … I heard a really loud almighty terrifying noise that sounded as if it was coming from right next to where I was standing" (emphasis added).
Ms Westlake deposed that "[t]he blast noise was out of the ordinary … the dust started to move quickly over the hill toward my property", and that "[i]n my 17 years working in mines … I have never experienced a blast with as much noise and vibration impact as the blast that occurred on 20 August 2020" (emphasis added).
Ms Westlake was not required for cross-examination.
[53]
Mr Ross Kereopa
In his affidavit dated 15 July 2021, Mr Kereopa, operator at the Boggabri coal mine, deposed that he lives on the same property as Ms Westlake. He deposed that "the vibration was intense, it was like going to a concert with the speakers shaking everything" and that "[w]hen the blast went off it sounded like it was just across the paddock. It gave me a fright …" (emphasis added).
Mr Kereopa was not required for cross-examination.
[54]
Ms Lynette Louis
In her affidavit dated 6 July 2021, Ms Louis, local resident, deposed that she lives at a property known as "Merrilong" located approximately 30km northeast of the mine. She deposed that "[a]t about 10.00 to 10.30AM on 20 August 2020, I was at home … I heard an almighty bang crash. The whole house shook … The noise was as if something had crashed into the house or the roof had fallen in". Further, that: "[i]n the past, I have felt vibrations from the other blasts … Other blasts I have experienced were nothing compared to the noise and vibration of the blast on 20 August 2020. The noise was much louder and the vibration much stronger on that day". On 24 August 2020, Ms Louis says she made a complaint to the EPA about the noise and vibration from the blast (emphasis added).
Ms Louis was not required for cross-examination.
[55]
Mr Simon Lund
In his affidavit dated 13 August 2021, Mr Lund, senior EPA investigator, deposed that on 20 August 2020 at about 11:19am, he received a complaint from the EPA's environment line in relation to a blast fired at around 10:30am hours at the mine "that the complainant reported as being the loudest blast ever heard".
In relation to the EPA's investigation of the impact of the blast at the mine, Mr Lund testified:
Q. Is this the reality, though, Mr Lund; you just didn't take any steps to get any version of events from any of the persons who were in the Boggabri Mine crib hut as to their experience of the blast, other than getting an account from Mr Byrnes and Ms Severin?
A. No, I believe we did take steps, in the notices and in the records of interviews.
…
Q. The reality is, isn't it, that you had no interest in making any inquiry of any person who perceived the blast other than the two persons, out of hundreds present there who had, to your knowledge, a complaint about affectation?
A. That's not the case. I, I made inquiries about it and came up with no names, and there weren't hundreds present in the crib hut at the time. My understanding is there was only a handful of people and some, most of those were contractors.
In relation to the reluctance of the defendant's employees to engage with the EPA, Mr Lund said as follows in cross-examination:
Q. Come on, Mr Lund, you're perfectly capable of finding out who was there and asking them questions about it, aren't you?
A. It's my experience that the miners themselves do not want to talk to us because they are fearful of losing their jobs and it takes direction to pull them in to talk to us.
[56]
Ms Jasmine Walden
In cross-examination, Ms Walden, EPA investigator, recalled that in relation to the EPA's interview with Mr Byrnes, Mr Byrnes informed her that he had a solicitor acting for him named Mr Andrew O'Halloran. However, Mr Byrnes did not explain to Ms Walden prior to affirming his affidavit on 27 July 2021 why he had retained Mr O'Halloran.
In relation to the EPA's interaction with Ms Druce, Ms Walden testified that she did not know Ms Druce, and was involved in the taking of a witness statement from her with Mr Lund. To her recollection, that was the extent of her dealings with Ms Druce.
[57]
Dr Alan Cameron (prosecutor's expert)
Dr Cameron holds a Bachelor of Science, Master of Science and a Doctor of Philosophy (PhD) all in mining engineering. He worked as a lecturer at the Western Australia School of Mines between 1984 and 1986, a project manager, senior research officer and consultant at the University of Queensland between 1986 and 1992, and as an office manager, principal and senior mining consultant at Golder Associates between 1993 and 2006. He worked at Rio Tinto as principal advisor, drill and blast between 2006 and 2014, and as manager, mining between 2014 and 2015. Between 2015 and 2021, Dr Cameron was the director and principal consultant at Aramac Consulting and provided consulting and contract services to the mining industry in explosives safety, wall control blasting, mine development studies, corporate standards for explosives, as well as review and supervision of drill and blast operations. Dr Cameron is the author or co-author of approximately 20 publications, has been involved in over 40 blasting related projects and worked in countries including Thailand, the United States, Guyana, Canada, Australia, France, Brazil, Indonesia, Mexico, England, Tanzania, Peru and Mongolia.
In his report dated 4 November 2021 (to which there were numerous objections and which were the subject of rulings), Dr Cameron sought to identify in relation to each of the timing charge, the stemming charge and the overloading charge, why he considered that the requirement of competence within the meaning of condition O1.1 of the EPL was not met by the defendant. Dr Cameron opined as follows (emphasis added):
Executive Summary
…
2.1.4 Two personnel, from Boggabri Coal Mine, impacted by noise from the blast were located approximately 2,892m south-east of the blast. Complaints of noise were received from other persons, including Roslyn Druce, approximately 7,230m northwest of the blast, and from Christine Westlake, approximately 11,942m northeast of the blast
…
2.1.7 In my opinion, [the blast] was not designed in a competent manner because:
2.1.7.1 the impact of airblast overpressure on personnel at Boggabri Coal Mine was not considered; …
…
2.4.3 … MIC [maximum instantaneous charge] is a primary contributor to vibration and airblast levels and given the MIC for [the blast] was approximately 10 times that of the previous blast … it is reasonable to expect a large increase in noise/airblast overpressure.
…
2.4.5 … large increase in noise/airblast overpressure, as compared to previous blasts, was likely to occur and foreseeable due to the reduction in stemming length and a very large increase in MIC. This was recognised by the shotfirer on the day.
…
a) Was the blast designed in a competent manner? And was the manner in which the blast was carried out done so competently? …
…
Stemming length
1.10 A Rule of Thumb commonly used for calculating stemming length from ISEE Blaster's Handbook (18th edition) and Orica's Pocket Blast Guide is stemming length = 20 - 30 times blasthole diameter. Applying this … 20 times the blasthole diameter of 0.229m for [the blast] is approximately 4.6m. This indicated that the Approved Designed Standard stemming length of 3.5m … is already less than that normally used and, therefore a further reduction of this length by 14% is a significant amount.
Fast timing
1.11 Progressive release of burden occurs when earlier firing blastholes have moved the rock in front of them (their burden) sufficiently to create a void that the holes behind (later firing) can break and move their burden rock into … When the timing of initiation of the blastholes is faster than the time it takes a hole to move the rock in front of it, explosive energy is confined laterally and is then directed upwards to the surface … This results in the explosive energy, in the form of high-pressure gases, prematurely bursting through the stemming length and venting to the atmosphere …. When the high-pressure gases are suddenly released into the air, they cause noise/airblast overpressure …
1.12 [The blast] was designed based on the utilization of electronic initiation (compared to non-electric specified in the Approved Design Standard) and a burden relief time of 0.8 - 1.5 ms/m. This initiation … does not provide good progressive release of burden …
Maximum Instantaneous Charge (MIC)
1.13 The blast design … resulted in a MIC or, quantity of explosive indicated within an 8ms time period, of 56,925Kg … The … [blast hazard analysis] shows an elevated Hazard Score (trigger value when exceeded additional controls should be considered) for overpressure when the MIC is greater than 5,000Kg. The blast … was more than 10 times this threshold level and therefore is not conservative and proven level as required under section 3.3.5 of the BMP …
Opinion
1.17 In my opinion, [the blast] was not designed in a competent manner because:
• it did not consider the potential impact on employees or facilities at the adjacent Boggabri Coal Mine or Tarrawonga Coal Mine. Two employees at Boggabri Coal Mine were injured by the noise/airblast overpressure from the blast and they were much closer to the blast than the residences where the blast monitors (BM1, BM2, BM3 & BM4) were located and the modelling was focused on.
• The decisions to reduce stemming length to 3.0m and change the initiation to fast timing did not conform to one of the objectives and associated control measures in the [BLMP], in particular, Section 3.3.5 … resulting in a high level of noise/airblast overpressure; and
• A hazard or risk assessment, with senior management approval, was not conducted for the blast design though significant changes were made to the stemming length and initiation timing compared to the Approved Design Standard …
…
Minimum Requirements
2.1 The minimum standard of competence … is to achieve designed parameters within +/- 10% tolerance …
Loading Data
2.7 … The blast design contained 1197 holes. The load sheets showed a few holes were not drilled and there were missing loading sheets such that there is an actual quantity of explosives loaded … for 1,000 holes …
2.8 … Of the 1,000 blastholes with loading data, 191 holes or 19% contained at least 10% more explosives than designed and 33 holes contained in excess of 20% more than the designed amount.
[58]
Dr Aimone-Martin (defendant's expert)
The expert called by the defendant, Dr Aimone-Martin, holds a Bachelor of Science in geological engineering, with a minor in mining engineering and a PhD in civil engineering from Northwestern University in the United States. In her curriculum vitae, she lists the following areas of specialisation: blasting consultant since 1988, a monitoring specialist since 1978; underwater blast permit applications; blast and monitoring plans since 2009; pre and post blast/construction structure surveys since 1984; community relations specialist since 1984; geotechnical engineering since 1975; contract specifications and regulatory since 2009; and education and training courses since 1980. Dr Aimone-Martin is an emeritus professor at the New Mexico Institute of Mining and Technology.
In her curriculum vitae, Dr Aimone-Martin refers to 124 selected current or recent consulting projects (2009-2020), and 96 presentations and publications. The 124 selected current or recent consulting projects identified by Dr Aimone-Martin demonstrate that she has primarily worked in the United States, and that she has worked on only one project in Australia (at Hazelwood power station in 2020-2021).
Dr Aimone-Martin's report dated 10 October 2022 was subject to numerous objections, a number of which were upheld, and numerous statements in her report were admitted as assumptions. Dr Aimone-Martin opined as follows in relation to the timing charge, referred to by her as charge 1 (footnotes omitted, emphasis added and correction made by witness in relation to the number of the relevant objective in cl 3.3.5 of the BLMP):
4.1 Charge 1: MCC carried out blast HRN_08_39_OB in a competent manner by programming the delay timing to create a "lifting" blast rather than a bench blast. Delay timing in milliseconds per meter of burden dimension (ms/m) to achieve progressive burden release is a design concept that only applies to bench blasting. It does not apply to the lifting blast HRN_08_39_OB, designed to promote fast uplifting of the caprock to improve overall rock fragmentation. In my opinion, the concept of burden relief timing is irrelevant to the design of the lifting blast. The timing design was appropriate to achieve the blast design objectives of improved fragmentation and worker safety in a competent manner.
…
5.1.1 Did MCC fail to carry out the blast in a competent manner by reason of it programming the electronic initiation system for the subject blast with a burden relief time of 0.8-1.5ms/m?
5.1.2 Response
In my opinion MCC carried out the blast in a competent manner and the blast design provided good progressive relief of the confined rock as it was planned. Six of the seven objectives outlined in section 3.3.5 of the Blast Management Plan were met by MCC. However, the sixth fifth objective that reads
"Charges detonate in the correct sequence and with inter-row delays that provide good progressive release of burden;"
is irrelevant to blast HRN_08_39_OB in that the blast was not designed as a bench blast in which time delayed blast holes progressively initiate laterally (e.g., horizontally) in the drilled burden direction. Rather, blast HRN_08_39_OB was designed as a vertically "lifting" (often referred to as a "sinking" blast) blast to achieve good fragmentation of the surface hard caprock. Hence, the allegation in Charge 1 that a delay timing of 0.8-1.5ms per meter (ms/m) of burden did not provide good progressive burden … relief time is based on the false premise the blast HRN_08_39_OB was a bench blast which it was not. In my opinion, the concept of progressive release of burden to form the basis of an incompetent blast is inappropriate. MCC indeed utilized an appropriate fast delay timing designed to achieve good progressive vertical release required for the lifting blast. Modifying bench blasting to create a lifting cut starting in the centre of the drill pattern is not precluded in the Drill and Blast Design Standard Fixed Pattern.
5.1.3 Supporting facts
5.1.3.1 The subject blast was not designed as a typical bench blast where horizontal burden relief timing may range from 3 to 20ms/m designed to promote lateral movement of rock free faces forming the bench while restricting vertical movement. Rather, blast HRN_08_39_OB was designed with two "sinking" or drop cuts (also referred to in the industry as a lifting cut), that started initiation in the confined center of the planned blasting area working outward toward free faces and required fast, accurate initiation timing to achieve fragmentation and vertical rock displacement.
…
5.1.3.3 …
i. Figure 5 shows aerial photograph comparisons of bench blast HRN_08_40_OB, with coarse, "blocky'' rock sizes, and lifting blast HRN_08_39_OB, with finer overall rock sizes. It is my understanding that the unexpected hard caprock layer present in bench blast HRN_08_ 40_OB (found during drilling for blast HRN_08_39_OB) caused shovel digging rates to decline, removal equipment to be damaged, and with the potential for injury to workers. … the decision to use a lifting shot with fast timing to achieve the objective of producing finer fragmentation and safer rock removal demonstrates that the blast was designed in a competent manner.
…
Figure 5. Comparison of blasts HRN_08_40_OB and HRN_08-39_OB indicating coarser, "blocky" fragmentation in the lower right foreground of photo(a) resulting from an unexpected hard caprock with the finer fragmentation shown in photo (b). Similar features found along the two remaining high walls are noted in each photo.
[59]
Findings of fact contended for by the prosecutor in relation to the timing charge
The prosecutor contended that the Court should make the following findings of fact in relation to the timing charge (some of which were also relevant to other charges):
1. a decision was made on behalf of the defendant to use fast timing for the blast which was a departure from the standard blasting practice at the mine;
2. no modelling was conducted to the south of the mine, notwithstanding that the Boggabri coal mine is located less than 3km to the south;
3. concerns were held by employees of the defendant about the use of fast timing; and
4. the use of fast timing did not provide for good progressive release of burden and led to high levels of noise and airblast overpressure.
The prosecutor contended that the blast had a burden relief time of 0.8-1.5ms/m. The prosecutor submitted that the evidence of this fact was not subject to a limitation under s 136 of the Evidence Act. I accept that submission, and I find established beyond reasonable doubt that the blast had a burden relief time of 0.8-1.5ms/m. The defendant's expert Dr Aimone-Martin calculated a burden relief time of 0.92ms/m. Even if that be correct, it would be within the range alleged in the timing charge.
[60]
Findings of fact contended for by the prosecutor in relation to the stemming length charge
The facts contended for by the prosecutor in respect of the stemming length charge are substantially the same as those relating to the timing charge set out above at [242]-[243]. The prosecutor contended that the Court should make the following findings of fact in relation to the stemming length charge:
1. as with the timing charge, a decision was made on behalf of the defendant to use reduced stemming for the blast which was a departure from the standard blasting practice at the mine;
2. no modelling was conducted to the south of the mine, notwithstanding that the Boggabri coal mine is located less than 3km to the south; and
3. the use of reduced stemming did not provide for good progressive release of burden and led to high levels of noise and airblast overpressure.
[61]
Findings of fact contended for by the prosecutor in relation to the overloading charge
The facts contended for by the prosecutor in relation to the overloading charge are substantially the same as those in relation to the timing charge set out above at [242]-[243].
[62]
Findings of fact contended for by the prosecutor in relation to the emission of noise charge
The facts contended for by the prosecutor in relation to the emission of noise charge are substantially the same as those in relation to the timing charge set out above at [242]-[243].
[63]
Findings of fact contended for by the defendant in relation to all charges
The defendant contended for the following finding of fact in relation to all four charges:
1. At "some stage" between 14 and 18 August 2020, Mr Gomez requested that Dr McKenzie carry out modelling on a conservative basis to meet the EPL 95 percentile limits, not merely the EPL absolute limits. Mr Gomez described the approach as having "two layers of conservatism".
I find that fact established on the balance of probabilities (and, if necessary, beyond reasonable doubt).
[64]
Prosecutor's submissions in relation to all charges
[65]
Prosecutor's submissions in relation to the blast monitor records
The prosecutor referred to the airblast overpressure and vibration levels recorded after the blast at the EPL monitoring points and dam monitors set out in the tables extracted above at [83]. The prosecutor acknowledged that the recorded airblast overpressure and vibration levels were within the limits of conditions L4.1 and L4.3 of the EPL, however submitted that that provided no answer to the alleged failure of the defendant to consider personnel at the Boggabri coal mine who on 20 August 2020 were located approximately 2.9km from the blast.
The prosecutor submitted that compliance with the EPL at BM1 located 8.3km north of the blast "says nothing" in answer to the defendant's failure to consider personnel at the Boggabri coal mine. Dr Cameron's evidence was that such failure meant that the design of the blast did not meet an overriding provision of the Australian Standard (the first paragraph of section 4.1) in relation to the use of explosives because no consideration was given to the impact on personnel at the Boggabri coal mine. That standard is partly extracted at [96]-[105] above.
[66]
Prosecutor's submissions in relation to the impact of the blast on lay witnesses
The prosecutor made the following submissions in relation to the evidence of witnesses as to the impact on them of the blast on 20 August 2020.
[67]
Mr Ryan Gomez
Mr Gomez, who was in the office at the mine at the time of the blast, described feeling "uncomfortable" after the blast because "the vibration was more than I would have anticipated", and he "thought the [d]efendant had exceeded its noise limit". He said that "after the blast and feeling the impact ... I most certainly thought we had exceeded the modelling that we did". Mr Gomez described the blast as "most certainly not an ordinary blast", and "not your every day blast", and explained that this was because it deviated from the defendant's "set of standards". He said that the "timing [was] quicker than the timing that we normally would use", and agreed that there was "a deviation from the standards … in relation to different loading rules". Mr Gomez also said that "the stemming length was slightly less than the design standard".
[68]
Mr Jonathon Byrnes
Mr Byrnes, a mine operator at the Boggabri coal mine, was at the "go line" at the time of the blast, which was located 2.9km from the blast. His evidence was that just prior to the blast, he "had pulled out his earplugs" and that he:
heard this almighty pop, like a gun shot going off right next to my head. This scared the crap out of me. About two or three seconds later I felt the overpressure blast. This felt like a forceful wind. I felt a shake in the ground. I looked over and I saw a blast had gone off at Maules Creek Coal Mine. I saw a mushroom cloud of dust.
The prosecutor referred to Mr Byrnes' evidence that he felt "pressure in both of his ears immediately after the Blast, which then became a ringing". He reported this to his supervisor who directed him to attend first aid. After seeing first aid, Mr Byrnes was taken to Boggabri Hospital. On assessment, Mr Byrnes was found not to have a burst eardrum and was referred for a hearing test.
The prosecutor also referred to Mr Byrnes' evidence that as "a result of his exposure to airblast overpressure and noise caused by the Blast", he experienced "constant ringing in both my left and right ears", that he found the ringing "to be annoying" and to affect his "ability to concentrate and focus". He also "noticed a distinct problem with my hearing especially when there is background noise". The prosecutor referred to Mr Byrnes' evidence concerning "ongoing pain", "three terrible ear infections", and difficulties in sleeping for which he has been prescribed sleeping tablets. Mr Byrnes also reported that the disruption to his sleep "caused by injuries arising from the Blast had caused him to suffer fatigue, stress and mood fluctuations, which had in turn caused him problems carrying out his employment and earning income".
The prosecutor referred to questions directed towards Mr Byrnes' credibility in cross-examination, "particularly in light of inconsistencies in the various versions he provided" and concerning the fact that he had subsequently lodged a workers compensation claim in respect of the injury to his hearing arising from the blast. The prosecutor submitted that any criticism of Mr Byrnes' credibility did not bear on the fundamental conclusions to be drawn from his evidence; namely, that he experienced a ringing in his ears immediately after hearing the blast which had endured, and that there was an ongoing detrimental impact on his physical wellbeing.
[69]
Ms Rebecca Severin
Ms Severin, an operator at the Boggabri coal mine who was outside the crib hut at the "go line" at the time of the blast, gave evidence that she heard two blasts, the second of which was "very loud and shook the ground and crib hut". Ms Severin's evidence was that "it was like the sound bounced off the de-mountable and then hurt [her] right ear as [she] turned [her] head". She felt "immediate" pain and "instantly grabbed [her] ear". After the blast, Ms Severin went to see first aid. She then went to Boggabri Hospital to have her ears checked, but no physical injury was identified. Ms Severin later attended a hearing specialist who did not identify any hearing impairment.
[70]
Other witnesses who experienced the blast
The prosecutor also referred to evidence, which it submitted ought be accepted, given by Ms Druce, Ms Westlake, Mr Kereopa and Ms Louis as to how they experienced the blast at their private residences. That evidence is summarised above at [181]-[189].
[71]
Prosecutor's conclusion in relation to the impact of the blast on lay witnesses
The prosecutor submitted that the Court should find that the blast on 20 August 2020 caused actual harm to human health, demonstrating the relevance and importance of Dr Cameron's approach that the likely presence of such persons ought to have been considered in order for the blast to have been carried out in a competent manner. Specifically, the prosecutor submitted, Mr Byrnes and Ms Severin experienced physical harm immediately after the blast such that they sought medical attention, with Mr Byrnes experiencing a ringing in his ears and Ms Severin experiencing pain in her right ear. Mr Byrnes' evidence was that the physical harm he sustained in the blast has had an ongoing detrimental impact on his physical wellbeing, with the ringing in his ears having endured, and him having issues with his hearing, ongoing pain and difficulties sleeping.
[72]
Prosecutor's submissions in relation to the evidence of Dr McKenzie
Referring to the first paragraph of Dr McKenzie's email sent on 14 August 2020 at 10:02pm (extracted above at [54]), the prosecutor submitted that Dr McKenzie's "doubts" about the ability to "reliably" model the impacts of 3.0m stemming and fast timing under the third option must be read in the context of the issues he had identified in the first paragraph of the email, including that "even with 3 metres, we may be pushing our luck in combination with fast timing", that his "modelling says that if we go to the fast timing, then we probably should be looking at 3.5 metres of stemming", and that he was "not sure how much confidence to have in the modelling". With the words "some depressing time", Dr McKenzie meant that he was "somewhat disappointed" with the results of the modelling as he was unable to come up with the answer he wanted despite "such a lengthy period of modelling".
The prosecutor submitted that notwithstanding the modelling conducted between 14 and 18 August 2020, Dr McKenzie could not resolve all uncertainties about the impact of the blast in circumstances where the blast was a departure from standard blasting practice at the mine.
[73]
Prosecutor's submissions in relation to the demeanour of Dr Aimone-Martin
In closing submissions, the prosecutor raised, in particular, the following aspects of Dr Aimone-Martin's evidence in cross-examination. First, Mr Leggat SC drew attention to the transcript extracted above at [227] in relation to the question of whether the MIC was conservative or not.
Mr Leggat also referred to Mr Lee's interjection in the cross-examination of Dr Aimone-Martin which is recorded below:
LEE: I think the witness has assumed that the blast is happening in America, that's why she continues to ask what distance.
HER HONOUR: That's not my understanding, Mr Lee, but Mr Leggat can put the question again.
LEGGAT
Q. I just want you to be aware that I'm going to make a submission to her Honour, based on the answers that you've given, that you are intentionally being not cooperative, do you understand that?
A. (No verbal reply)
Mr Leggat submitted that the Court will need to form a view as to whether Dr Aimone-Martin was choosing to answer questions where adjectives were used and as to whether she was, at times, intentionally non-cooperative.
Mr Leggat also submitted that where the defendant chose to go into evidence by calling Dr Aimone-Martin, and where Dr Aimone-Martin supported her reasoning process by referring to matters outside the particulars in the summonses, such approach did not have the effect of amending the particulars which remained within the metes and bounds of the prosecutor's case. However, the prosecutor was entitled and obliged, [10] to engage with the reasoning process of Dr Aimone-Martin within the metes and bounds chosen by her in the process of her reasoning; that is, the prosecutor's cross-examination of Dr Aimone-Martin was not intended to and could not amend the particulars of the summonses. Mr Leggat drew attention in particular to the cross-examination of Dr Aimone-Martin in relation to the contravention of the blast noise limit imposed by condition 18 of the EPA Act approval at the Coomalagah monitor:
HOWARD: It may be covered by your Honour's previous rulings, but once again, these are questions that do not find any basis in the charges that our client faces.
HER HONOUR: They find a basis though in the evidence that your expert has provided, Mr Howard. I allow the question, Mr Leggat.
…
LEGGAT: The difficulty with the objection, Is that the witness's reasoning process is set out on page 37 at (iv) where the witness says in effect what happened at Coomalagah "cannot be considered a basis for dealing with explosives in an improper and inefficient manner" but what I'm challenging is the witness's view, her reasoning process that "The contravention of the blast noise limit at the non-MCC monitoring site cannot be considered a basis for dealing with explosives in an improper and inefficient manner". What I'm suggesting to her is that the contravention of the blast noise can be considered. That is, that her reasoning process there is wrong. Then if I get an agreement with that, I'll put to her the point that therefore her view about the conclusion for charge 5 is also wrong.
HER HONOUR: Yes, I understand. I allow it, Mr Howard. The expert has introduced this evidence herself. It's being explored in order to understand her reasoning process more generally and the methodology that she's applied. …
…
Q. Let's look at what [the second Lewandowski report] … says about Tarrawonga weather station in the last paragraph: "In summary, based on the undertaken assessment, it is unlikely that atmospheric conditions on 20 August 2020 played a role in the increase in air vibration levels, especially from BM1 to BM4 stations." You agree with that conclusion, don't you?
A. BM1 to BM4 belongs to MCC. Are you asking me about that increase in air vibration at BM1 and BM4? How does that come into play here?
Q. The question I asked you is that
A. I don't understand.
Q. --you agree with the sentence which states "In summary, based on the undertaken assessment, it is unlikely that atmospheric conditions on 20 August 2020 played a role in the increase in air vibration levels, especially for BM1 to BM4 stations." … don't you?
A. We haven't completely
OBJECTION
WITNESS: I'm sorry.
HER HONOUR: Why? Mr Howard, I think it's an entirely unobjectionable question.
HOWARD: You can see what's happening here … the prosecutor, who hasn't called a witness, is not cross examining this witness about this witness' evidence but seeking to put opinion evidence that wasn't put by its own expert.
HER HONOUR: Mr Leggat?
LEGGAT: These two [Lewandowski] reports are in for all purposes. There was no ruling made as to any limited use. They directly contradict this witness' approach. As a question of fairness, I am giving her an opportunity to point out why it is that she disagrees with something that is--
HER HONOUR: I allow these questions.
[74]
Defendant's submissions in relation to the evidence of the lay witnesses
The defendant submitted that the Court should find that the evidence of the two workers at the Boggabri coal mine, Mr Byrnes and Ms Severin, and that of the occupants of the private residences in the general vicinity of the mine, namely Ms Druce, Ms Louis, Ms Westlake, and Mr Kereopa, had no probative value in the resolution of the questions for determination, and that the Court should place no weight on their evidence. Two bases were put for finding that their evidence was "bereft of probative value".
First, there was no "sensible basis" upon which a lay person's subjective perception of the noise and vibration generated from the blast could inform the question of whether the blast was designed or carried out in a competent manner, a fortiori, when the levels of the airblast overpressure and vibration complied with the limits under the EPL. In particular, the subjective perceptions of those persons could not inform the questions raised by the elements of the emission of noise charge under s 140(1) of the POEO Act. To contend that this evidence was relevant and could "rationally inform" the Court of fact as to the elements of the offences charged involved impermissible reasoning, working backwards from subjective perceptions about the effect of the blast in the face of "objective evidence that operating in a highly regulated industry, in which complaints from members of the public are common, the defendant was bound to comply with the airblast overpressure and vibration limits stipulated in the EPL, and that it complied with those limits". This would "all the more so be an exercise in impermissible reasoning" which would necessarily result in a "skewed and distorted conclusion", inevitably placing a disproportionate weight on the evidence of the subjective perception of a small subset of persons selectively chosen by the prosecutor to give evidence. There was no basis to conclude that the perceptions of this "small subset of persons" were "in any way representative of the perception of a far greater number of persons who experienced the blast, which clearly numbered at least in the hundreds". The prosecutor had made no attempt to adduce any evidence from the multitude of other persons who did not complain about the blast. Nor had the prosecutor made any attempt to establish that such perceptions were "statistically representative, or in any way representative".
[75]
Defendant's submissions in relation to work health and safety, and the evidence of Dr McKenzie and Mr Welch
The defendant submitted that having identified inadequate fragmentation as a work health and safety issue arising from the previous blast conducted on 7 August 2020, it was bound to discharge the duty of care owed to its employees by addressing the issue, both at common law and in accordance with s 19 of the Work Health and Safety Act. As Dr Cameron agreed, it would have been "remiss of a person in the position of the defendant, where there was a work health and safety problem concerning fragmentation, not to deal with it". It was the need to address the work health and safety issue posed by inadequate fragmentation, and a recognition of the need to remain compliant with environmental constraints, that prompted the defendant to retain Dr McKenzie. In oral submissions, Mr Howard referred the Court to ss 13 to 34A of the Work Health and Safety Act, and submitted that this "was an extremely important circumstance in this case that's been largely, almost completely glossed over by the prosecutor".
Again, the defendant submitted that as the operator of a coal mine, it operates in a highly regulated environment. In so far as noise (airblast overpressure) and vibration caused by mine blasting is concerned, the EPL set clear limits as to what levels were to be achieved, both as absolute limits and as 95 percentile limits, referable to certain sites nominated in the EPL and selected on the basis that they are representative of residential receivers. Dr McKenzie was instructed to carry out modelling to predict the levels of vibration and airblast overpressure at the four monitoring locations nominated in the EPL (and also to predict flyrock in order to be confident of the clearance zone as a safety measure). The modelling was based upon a number of scenarios involving various stemming length and timing parameters. The defendant, through Mr Gomez, had requested that such modelling be carried out by Dr McKenzie with the main intent "not to hurt anyone and be in [sic] environmental [compliance]".
The defendant submitted that in the design and implementation of the blast, guided by the modelling and advice of Dr McKenzie, it achieved both objectives the final design was intended to achieve; that is, the objective of achieving better fragmentation and, at the same time, the objective of complying with the EPL limit conditions pertaining to airblast overpressure and vibration. In light of the "satisfaction of those objectives", Dr Cameron "conceded that those circumstances alone were indications of competence on the part of [the defendant]". In relation to the evidence of the shotfirer Mr Welch, the defendant submitted that although he had concerns regarding the timing of the blast, he raised those concerns up the chain to the engineering team, and following discussions, directed the crew working on the blast to recommence work.
[76]
Defendant's submissions in relation to the evidence of Dr Aimone-Martin and the allegations particularised in the charges
The defendant submitted that the prosecutor must be held to the specific allegations particularised in the summonses, and had repeatedly during the course of the trial "strayed impermissibly from the charges it brings" by seeking to adduce evidence, whether through its own witnesses or by putting propositions in cross-examination to Dr Aimone-Martin which, "while seemingly intended to establish that the conduct of the defendant was in some way deficient", were not probative of the specific allegations particularised in the charges. The proceedings were "not some sort of broad inquiry" into the blast, and each of the allegations particularised was required to be proved beyond reasonable doubt.
If the Court preferred the evidence of Dr Cameron to that of Dr Aimone-Martin in one or more respects, it did not follow that verdicts of guilty should be entered. Rather, the Court must weigh in its assessment of the ultimate question of guilt the evidence of Dr Cameron, and then determine whether the prosecutor has discharged its burden or not.
[77]
General findings in relation to all charges
I am satisfied beyond reasonable doubt and make the following findings of fact in relation to all charges. Further, I make specific findings of fact in relation to each of the charges in the Court's consideration below.
As I have previously found, an issue of inadequate fragmentation had arisen in relation to the overburden mine blast carried out on 7 August 2020 on the Herndale seam in a location adjacent to the blast the subject of these proceedings. There was poor or very coarse fragmentation in the upper areas of that blast which was the first blast to be carried out in the area of the Herndale seam in two years. Achieving adequate fragmentation of rock is recognised as a key objective of mine blasting, directed to both the safety of workers and the efficient commercial operation of the mine by enabling an efficient dig rate.
Inadequate fragmentation of the caprock in the Herndale seam had resulted in poor digging conditions and safety risks to workers during the loading of overburden into trucks, including neck and body-jarring injuries. A related consequence was that the digging and removal of overburden became more time consuming and less efficient, and detracted from the commercial operation of the mine.
The issue of inadequate fragmentation was raised at a meeting of mine operators on Thursday, 13 August 2020 prior to the blast originally scheduled for 19 August 2020. Also on around 13 August 2020, Mr Gomez advised Dr McKenzie that "the pattern is already drilled or almost completed so there is no room to make any adjustments". As a result of the "late stage" of his engagement, there were limited adjustments Dr McKenzie could make to mitigate the caprock fragmentation issue. Consequently, the only design aspects that could be controlled to change the fragmentation outcome for the blast were to the stemming length and the timing.
As I have previously found, on 14 August 2020, Dr McKenzie was engaged to provide advice in relation to what the defendant could do in the time available before the scheduled blast, with an estimated 30-50% of the blast holes already drilled, in order to achieve better fragmentation of the caprock. Specifically, Dr McKenzie was engaged to provide advice on timing and stemming length for the blast to minimise caprock and improve fragmentation. In relation to what he discussed with Dr McKenzie in the phone call at 5:08pm on 14 August 2020, Mr Gomez' evidence in examination in chief was that "it was around … reducing the stemming length and probably increasing the, increase the timing or do something different to our traditional timing for us to kind of address that caprock issue".
[78]
The blast monitor records
In relation to the blast monitor records, it was common ground that the airblast overpressure and vibration levels were within the limits of conditions L4.1 and L4.3 of the EPL. However, I find as submitted by the prosecutor, that that provides no answer to the alleged failure of the defendant to consider personnel at the Boggabri coal mine who, on 20 August 2020, were approximately 2.9km from the blast. I also find it relevant to consider the airblast overpressure and vibration levels recorded by the two blast monitors at the Tarrawonga coal mine, the Coomalagah monitor (located approximately 12.5km south-east of the blast) and the Tarrawonga monitor (located approximately 9.7km south of the blast), by the blast monitors at two private residences Wilberoi East (located south of the blast) and Goonbri East (located east of the blast), and at the Boggabri trigger unit (located south of the blast) which recorded airblast overpressure and vibration levels after the blast on 20 August 2020.
The results recorded by the Coomalagah and Tarrawonga monitors are set out below in an email from Ecotech to Mr Sebastien Moreno of Whitehaven Coal dated 20 August 2020 at 10:28am:
Station Name Peak Air Blast (dB) Peak Resultant (mm/s)
Coomalagah 125.4 0.10
Tarrawonga 118.8 0.12
[79]
The results at Wilberoi East, Goonbri East and at the Boggabri trigger unit are summarised in the table reproduced below attached to an email dated 8 October 2020 from Mr Peter Forbes, health safety and environment manager at the Boggabri coal mine, to EPA investigator Mr Lund:
Vibration (mm/s) Overpressure (dBL)
7374 Wilberoi East 0.83 109.0
7391 Goonbri East 0.52 100.1
I find established, beyond reasonable doubt, that the defendant failed to consider personnel at the Boggabri coal mine, located approximately 2.9km from the blast. In that respect, Dr Cameron's evidence, which I accept, is that such failure meant that the design of the blast did not meet an overriding provision of the Australian Standard (the first paragraph of section 4.1) in relation to the use of explosives because no consideration was given to the impact on personnel at the Boggabri coal mine.
[82]
The impact of the blast on lay witnesses
I find established, beyond reasonable doubt, that the blast had considerable impact on lay witnesses, in particular Mr Byrnes and Ms Severin, each of whom presented to Boggabri Hospital after the blast. Each presented as a credible witness, notwithstanding the defendant's attempts to undermine their credibility, in particular because of a workers' compensation claim or personal injury claim in the case of Mr Byrnes.
Mr Gomez, the defendant's technical services supervisor at the time, was uncomfortable about the blast, described it as "most certainly not an ordinary blast", and that after feeling the impact of the blast, he "most certainly thought we had exceeded the modelling that we did".
Ms Druce, Ms Westlake, Mr Kereopa and Ms Louis also gave evidence in relation to their experience of the blast at their homes. Ms Westlake, Mr Kereopa and Ms Louis were not required for cross-examination. Ms Druce was cross-examined in relation to her long history of opposition to the mine. I find her to have been a truthful witness, and accept her evidence that she first thought there had been an earthquake, and that she had never felt that much vibration from a blast before.
I accept the evidence of these witnesses in relation to their experiences of the blast. I find that it was not an ordinary blast and that, as Ms Westlake testified, the blast noise was out of the ordinary, she having never experienced in her 17 years working in mines a blast with as much noise and vibration impact, that as Mr Kereopa testified, the vibration was intense, and that as Ms Louis testified, having felt vibrations from other blasts in the past, those blasts were nothing compared to the noise and vibration of the blast on 20 August 2020.
[83]
The evidence of Mr Welch
As I have found above, established beyond reasonable doubt, Mr Welch, one of the shotfirers responsible for loading and tying up the shot on 20 August 2020, held real concerns that the shot was "all too close", and that alarm bells rang in his head in relation to two holes "going off at the same time let alone close together". Mr Welch had not seen timing like that previously. Mr Welch's concern was that there were a lot of holes going off really close together which the shotfirers were not trained to do.
As at 19 August 2020, in relation to noise vibration, Mr Welch was concerned about the timing being "way too quick", and also about related poor fragmentation and environmental impact in terms of noise and vibration. When tying the shot up on 19 August 2020, the blast crew discovered that a lot of holes were going off very quickly, close together. Mr Welch pulled the shot on 19 August 2020 because he was not entirely happy with the timing, and went and had discussions with the engineers. In those discussions, he raised concerns about the quickness of the timing of the entire shot, and said that holes were going off together.
His recollection of the blast on 20 August 2020 was that it was the most impressive shot he had ever seen. It was very quick and went off together. He said it was visually spectacular. If one looked at the shot fired prior to that fired on 20 August 2020, one could see it firing "nice and sequentially". One could see it "peeling away" and "timing across the shot in orderly fashion". The blast on 20 August 2020 just went "bang".
[84]
The evidence of Dr McKenzie, and the work health and safety risks posed by inadequate fragmentation
I find established beyond reasonable doubt that as at 10:02pm on 14 August 2020, Dr McKenzie had expressed considerable concern that after a lengthy period of modelling he could not come up with the answer he wanted, and was "a little disappointed, depressed". Dr McKenzie accepted that he was involved with the design of the blast at a "rather late stage", and that there were not many options available to address the issue of course fragmentation. He asked the defendant whether any of the recommendations in his first report had been implemented, and the answer was no. At the time of his engagement, an estimated 30-50% of the blast holes had been drilled.
I find that the defendant had engaged a highly accredited expert to deal with the issue of inadequate or very coarse fragmentation occurring in the uppermost section of the benches. I accept that a genuine concern was held by the defendant in relation to inadequate fragmentation placing the health and wellbeing of shovel operators at risk, as well as a concern in relation to the efficient commercial operation of the mine by enabling an efficient dig rate. However, I also find that Dr McKenzie had provided a report to the defendant in December 2019, and that as at August 2020 none of his recommendations had been implemented.
Dr McKenzie said that the stemming length for the blast holes of 3.0m deviated from the defendant's approved design standard and from what a normal standard would be, and that the whole blast was being done differently. As at 10:02pm on 14 August 2020, Dr McKenzie considered that even with 3.0m "we may be pushing our luck in connection with blast timing", that his modelling said that if one went to the fast timing "then we probably should be looking at 3.5m stemming", and that he was not sure "how much confidence to have in the modelling".
The prosecutor submitted, and I find, that notwithstanding the modelling conducted between 14 and 18 August 2020, Dr McKenzie could not resolve all the uncertainties about the impact of the blast in circumstances where the blast was a departure from standard blasting practice at the mine and that he had expressed doubt about how much confidence could be had in the modelling.
[85]
The evidence of Dr Aimone-Martin
In closing submissions, the prosecutor drew attention to particular aspects of Dr Aimone-Martin's evidence in cross-examination. Those aspects are set out above at [262]-[266].
I find that Dr Aimone-Martin was frequently not responsive to the prosecutor's questions, in particular in relation to the overloading charge, requiring the Court to direct her to answer questions. At times, Dr Aimone-Martin either misunderstood or preferred not to answer the questions put to her. In terms of relevant expertise, Dr Aimone-Martin has primarily worked in the United States, and only on one project in Australia at Hazelwood power station in 2020-2021. That project did not raise issues similar to those raised in these proceedings. Since 2009, she has experience in relation to only two projects involving open cut coal mines.
Dr Cameron had significantly greater experience of mining in Australia and of blasts of the kind conducted at the mine on 20 August 2020, made concessions where appropriate, was a generally non-combative witness disposed to assisting the Court where he could, and gave all of his evidence in good faith. That is not to suggest that Dr Aimone-Martin was not a witness of good faith, however her general demeanour and very limited experience in Australia and in relation to open cut coal mines has led me to prefer the evidence of Dr Cameron.
[86]
Construction of s 64(1) of the POEO Act and condition O1.1 of the EPL
Each of the timing charge, the stemming length charge and the overloading charge raises the proper construction of s 64(1) of the POEO Act, and condition O1.1 of the EPL.
The elements of an offence against s 64(1) of the POEO Act are:
1. holding an EPL; and
2. contravening any condition of that EPL. [11]
As previously noted, s 64(1) of the POEO Act is a strict liability offence: EPA v Sydney Water (Pain J) at [2]. [12]
It was not in controversy that the defendant at all relevant times held an EPL. Accordingly, the issues which arise in relation to the alleged offences against s 64(1) are the proper construction of a condition of an EPL, the proper construction of condition O1.1 including the expression "licensed activities", and whether condition O1.1 was contravened in the circumstances particularised.
[87]
Proper construction of a condition of an environment protection licence
Each of the timing charge, the stemming length charge and the overloading charge alleges a breach of condition O1.1 of the EPL which provides that "[l]icensed activities must be carried out in a competent manner".
I am satisfied that the EPL is an instrument within the meaning of s 3(1) of the Interpretation Act 1987 (NSW) (Interpretation Act) being an instrument made under the POEO Act. Section 3(1) of the Interpretation Act provides as follows:
instrument means an instrument (including a statutory rule or an environmental planning instrument) made under an Act, and includes an instrument made under any such instrument.
In Verde Terra Pty Ltd v Central Coast Council; Central Coast Council v Environment Protection Authority (No 9) [13] Pepper J at [519] said:
… EPL 11395 is an "instrument" for the purposes of the Interpretation Act (see the definition of that term in s 3(1) of that Act and, by analogy, authorities such as Caroona Coal Action Group Inc v Coal Mines Australia Pty Ltd (No 2) (2010) 172 LGERA 25; [2010] NSWLEC 1 (authorisation under the Mining Act 1992) and Chief Environmental Regulator of the Environment Protection Authority v The Forestry Corporation of New South Wales [2018] NSWLEC 10 (licence issued under Pt 6 of the Threatened Species Conservation Act 1995)).
It is true that unlike a development consent which operates in rem, [14] a licence operates in personam, [15] and that an EPL "may be varied unilaterally by the EPA". [16] However, there appears to be no reason why, by analogy, a licence would not, like a development consent, be construed according to the ordinary principles of statutory construction. In Herzfeld and Prince, [17] the learned authors refer to the decision of Colvin J in Sandalwood Properties Ltd v Hantley Management Ltd [18] as follows:
Three kinds of instrument given force by statute have been the subject of considerable case law: patents, industrial awards and agreements, and development consents … The principles developed in these contexts may also be useful by analogy in other contexts. For instance, the principles relating to the construction of development consents have been applied to the construction of an Australian Financial Services Licence.
In Weston Aluminium, Pain J at [31] said as follows in relation to the interpretation of a licence:
… A licence also gives rise to significant legal obligations and criminal offences if breached. It is important that it be certain and readily definable from a limited range of documents. …
[88]
The proper construction of condition O1.1 of the EPL, and the phrase "in a competent manner"
[89]
Prosecutor's submissions in relation to the proper construction of condition O1.1 of the EPL
In relation to the proper construction of condition O1.1, the prosecutor submitted that the "proper enquiry" is whether the impugned conduct falls short of the standard required to meet the threshold of competence: were the licensed activities carried out in a less than competent manner? The prosecutor submitted that firstly the ordinary meaning of "competent" is to "undertake a task with the necessary and satisfactory level of skill", and that a condition that activities be carried out in a "competent manner" is a condition requiring those activities to be carried out with necessary and satisfactory levels of skill. In the context of an EPL, it must be coloured with the need to consider environmental risk and the nature of the activities themselves.
Secondly, the prosecutor submitted that it is necessary for the Court to consider whether, if the EPL is construed as a whole, compliance with condition L4 which relates to blasting and in particular L4.1 (which relates to airblast overpressure level from blasting operations at the EPL monitoring points) means that a charge for breach of other conditions related to blasting cannot be sustained. The prosecutor submitted that the Court should not adopt a construction of the EPL such that compliance with condition L4 is a complete answer to the three charges for the following four reasons:
1. Condition O1.1 directs attention to the way in which licensed activities are carried out. It is, to use the words of Craig J at [65] in Environment Protection Authority v Huntsman Corporation Australia Pty Ltd (Huntsman), [23] "fundamental in the control of the regulated activity". It is a condition that seeks to regulate activities by reference to a standard of satisfactory skill, and the answer that the outcome of actions should only be evaluated by reference to whether the outcomes of the actions otherwise comply with the licence does not give sufficient weight to the words and purpose of the condition.
2. Condition O1.1 must be given work to do. If all that the EPL sought to regulate in relation to the carrying out of blasting activities at the mine was the airblast overpressure at four monitoring locations and not the manner in which the activities are carried out, there would be no need for the condition to be included (or it could have been the subject of an express exemption in relation to airblast overpressure).
3. It may be that in some circumstances the carrying out of licensed activities in a competent manner requires the holder of a licence to give consideration to factors that are not otherwise directly addressed by the terms of the EPL, which may be general because the licence does not address a particular issue, or may be required by the particular circumstances in place at the time. Accordingly, what was permitted under the EPL is prescribed by the EPA to be a "general standard of competence, at all times and adapted to the prevailing circumstances".
4. Condition O1.1 should be given work to do in relation to the management of risk. It may be that activities are not carried out competently because they expose a "huge risk of environmental harm: and it may be that harm does not actually materialise".
[90]
Defendant's submissions in relation to the proper construction of condition O1.1 of the EPL
The defendant submitted that the EPL "needs to be considered as a whole", and that it contains a subset of conditions expressly directed to the regulation of mine blasting: conditions L4.1 to L4.8, the only conditions of the EPL identified in cl 2.3 of the BLMP as relevant to blasting. Conditions L4.1 to L4.4 impose numerical limits on the levels of vibration and airblast overpressure permitted from blasting operations as recorded at the four EPL monitoring points. The limit conditions for airblast overpressure and vibration were submitted to be wholly consistent, in purpose and effect, with the limits for the same parameters imposed by condition 18 of the EPA Act approval, except that the EPL imposes those limits with respect to the four nominated monitoring points, BM1 to BM4, chosen as representative of residences on privately owned land. The defendant submitted that the four EPL monitoring points were "chosen by the regulator, on the basis that they're representative of the residential receivers" and that "the obligation in relation to airblast overpressure certainly [did] not extend to other points of the compass". The defendant did not submit that condition O1.1 has no work to do, but that in relation to blasting "blasting is a particular part of the mining activity which are the subject of express provisions in the licence".
Further, the defendant submitted that there has been no published decision involving a contested allegation of a contravention of a licence condition in the form of condition O1.1. The decision of the CCA in Genkem Pty Ltd v Environment Protection Authority [24] (Genkem) was "not such a decision". That case concerned whether a condition of a licence issued under the repealed Pollution Control Act 1970 (NSW) which provided that "matter and substances on the premises shall be processed, handled, moved and stored in a proper and efficient manner" was within power, and whether it was too general in its terms and thus, in effect, void for uncertainty. It was in that context that its meaning was considered by Gleeson CJ at 39B-44E (Powell JA and Dunford J agreeing).
In Environment Protection Authority v Collex Pty Ltd (Collex), [25] Bignold J published sentencing remarks in proceedings for an offence against s 64 of the POEO Act for an admitted contravention of a condition "in the form of condition O1.1". Bignold J at [23] cited part of the judgment of Gleeson CJ in Genkem, and at [24] remarked that he "would respectfully apply [that] understanding of the true nature of the obligation imposed by the Licence Condition [that has been] contravened in [Collex]" (being in the form of condition O1.1).
[91]
Competence and incompetence
The defendant submitted that the allegation in each of the timing charge, the stemming length charge and the overloading charge that "[t]he defendant did not carry out the licensed activities in a competent manner" was "logically synonymous" with an allegation that it carried out the particularised licensed activities in an incompetent manner. [31]
[92]
The mental (or fault) element of incompetence
In relation to the prosecutor's characterisation of s 64(1) of the POEO Act as a strict liability offence, the defendant submitted that that proposition is established and correct in so far as it is directed to the elements of that section itself. However, that did not end the inquiry as to whether there is a mental element or fault element required to be proved. The inquiry must also be directed to the elements of condition O1.1, which in its terms does include a mental (or fault) element, namely incompetence in the manner of carrying out the licensed activity. The defendant submitted that this mental or fault element must be proved beyond reasonable doubt and that it has long been established in the context of charges of criminal negligence that establishing the mental element of negligence to a criminal standard requires more than establishing negligence in the civil law. The principle is that in order to amount to criminal negligence, what must be established is such a serious departure from a reasonable standard as to warrant criminal punishment. [32]
Whilst in this case the Court does not have before it any charge of criminal negligence, and the defendant does not contend that the concept of negligence is the same as or should be conflated with the concept of incompetence, an allegation of a contravention of condition O1.1 "which could be made in either a civil or criminal context" is made by way of a criminal charge. Applying by analogy the principles applied in consideration of criminal negligence, the defendant submitted that in a criminal proceeding involving an allegation that a licensed activity was not carried out in a competent manner, it is necessary to prove, on an objective assessment, a sufficiently serious departure from a reasonable standard of competence in the manner of carrying out the particularised licensed activity as to warrant criminal punishment.
[93]
Consideration of, and conclusions in relation to the proper construction of condition O1.1 of the EPL
In Huntsman, Craig J at [65] said as follows in relation to conditions imposed by an environment protection licence (emphasis added):
Conditions imposed upon an environment protection licence traverse a spectrum of obligations. Some may be seen to be merely procedural, the consequences of non-observance of which are not necessarily adverse to the environment. Others may be regarded as more fundamental in the control of the regulated activity. A condition requiring that the activity be carried out in a competent manner is a condition of the latter kind.
Plainly, condition O1.1 of the EPL is of the latter kind referred to by Craig J in Huntsman, namely a condition more fundamental in the control of the regulated activity.
Genkem concerned a condition of a licence granted under the now repealed Pollution Control Act 1970 (NSW) which provided: "L6 Matter and substances on the premises shall be processed, handled, moved and stored in a proper and efficient manner." Gleeson CJ said at 41 (emphasis added): [33]
When regard is had to the legislative power pursuant to which condition L6 was imposed, and to the preamble to the licence conditions quoted above, as well as to the immediate context of the condition, it becomes reasonably apparent that the reference to matter and substances is a reference to matter and substances capable of polluting the environment. I would reject the submission, advanced on behalf of the appellant, that there would be a contravention of condition L6 if the appellant failed to store office stationery and paper clips in an efficient manner. For the same reason, an issue as to whether there had been failure to deal with matter and substances in a proper and efficient manner would fall to be considered according to the possible environmental consequences of the acts or omissions in question. Conduct which had no possible environmental consequences, but was related solely to the profitability of the appellant's business, would be outside the purview of the condition.
In Collex, Bignold J at [21] applied "this understanding of the true nature of the obligation" imposed by the licence condition contravened in that case, being a condition in the following terms: "All activities carried out on the premises must be carried out in a competent manner" (a condition in relevantly identical terms to condition O1.1 of the EPL here). According to his Honour (emphasis added): "[t]his means that it is the possible environmental consequences of the contravention that give content and colour both to the obligation and to the consequences of breach of that obligation."
[94]
The timing charge: alleged offence against s 64(1) of the POEO Act
In the timing charge, the prosecutor alleges that the defendant designed and carried out the blast otherwise than in a competent manner in contravention of condition O1.1 of the EPL. The prosecutor alleges that between 4 and 20 August 2020, the defendant breached s 64(1) of the POEO Act in contravening condition O1.1 by failing to carry out the blast in a competent manner; specifically, that the defendant programmed the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m which did not provide good progressive release of burden as required under cl 3.3.5 of the BLMP. The prosecutor alleges that by programming the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m, the defendant initiated the blast with "fast timing" which did not provide good progressive release of burden.
[95]
Prosecutor's submissions in relation to the timing charge
[96]
The prosecutor's reliance on Dr Cameron's evidence concerning the timing charge
The prosecutor referred to Dr Cameron's evidence that noise and airblast overpressure are created when the timing of initiation of blast holes does not result in the progressive release of burden. Dr Cameron explained that "burden release" is the distance to a free face at the time an explosive charge is detonating. Progressive release of burden occurs when earlier firing blast holes have moved the rock in front of them, the burden, sufficiently to create a void into which the holes behind can move their burden of rock into. When the timing of the initiation of blast holes is faster than the time it takes a blast hole to move the rock in front of it, the explosive energy is confined laterally, and is directed upwards towards the surface and the explosive energy, in the form of high-pressure gases, prematurely bursts through the stemming length and vents into the atmosphere, causing noise and airblast overpressure.
The prosecutor referred to Dr Cameron's opinion that the non-electronic initiation timing specified in the design standard corresponded to a burden relief time of 10-15ms/m which is accepted in the industry as providing for a progressive release of burden. However, the timing used in the blast through the electronic initiator resulted in a burden relief time of 0.8-1.5ms/m. Dr Cameron's opinion was that this did not provide "good progressive release of burden" because "there [was] not enough time for an earlier firing hole to move its rock so that a later firing hole has a void to move its rock into".
In his report dated 4 November 2021, Dr Cameron explained that the "fast timing" used in the blast resulted in a MIC of 56,925kg, approximately 10 times greater than the 5,000kg MIC of blasts designed using the initiation timing based on the design standard that applied to the blast. The MIC is the maximum amount of explosive charge that is initiated within an 8ms time window. Dr Cameron's opinion was that as the MIC is a primary contributor to vibrations and airblast levels and given that the MIC for the blast was approximately 10 times that of the previous blast, it was reasonable to expect a large increase in noise and airblast overpressure. Dr Cameron opined that "a large increase in noise/airblast overpressure, as compared to previous blasts, was likely to occur and foreseeable due to the reduction in stemming length and very large increase in MIC".
[97]
The prosecutor's submissions in relation to Dr Aimone-Martin's evidence concerning the timing charge
In relation to the evidence of the defendant's expert, Dr Aimone-Martin, the prosecutor submitted that her evidence must be considered "in light of her concessions in cross-examination that she did not have experience related to open-cut coal mining in Australia and that she had only been involved in two projects involving open-cut coal mines since 2009". Dr Aimone-Martin also accepted that the one project listed in her curriculum vitae which related to Australia did not consider any of the issues the subject of the charges in these proceedings.
The prosecutor referred to Dr Aimone-Martin's opinion that the blast was "carried out in a competent manner" by programming the electronic initiation system for the blast with a burden relief time of 0.92ms/m, which is between 0.8 and 1.5ms/m. This conclusion was premised on Dr Aimone-Martin's view that the design of the blast was properly characterised as a "lifting blast", and that the objective of "good progressive [release] of burden" in cl 3.3.5 of the BLMP was irrelevant. The prosecutor submitted that that position should not be accepted for the reasons given by Dr Cameron. As explained by Dr Cameron, cl 3.3.5 of the BLMP applies to all blasts conducted at the mine. Lifting blasts are not excluded or otherwise exempt. Dr Aimone-Martin was "re-writing" cl 3.3.5 by deleting the requirement that "[c]harges detonate in the correct sequence and with inter-row delays that provide good progressive release of burden". The prosecutor submitted that Dr Aimone-Martin was "therefore wrong in concluding that the blast did not need to be designed with good progressive burden relief". In any event, as Dr Cameron explained, even accepting Dr Aimone-Martin's premise that what was required was good vertical release, rather than good progressive burden release, the fast timing that was adopted did not provide for this.
The prosecutor submitted that, as explained by Dr Cameron, the failure to meet the blast design objectives in cl 3.3.5 of the BLMP directly contributed to the high levels of airblast overpressure from the blast. In cross-examination, Dr Aimone-Martin was prepared to "absolutely" agree that if slower timing had been used in the blast, the consequence would have been "enough time for the earlier firing hole to move its rock into the latter firing hole so that there was a void that the rock could be moved into and that the explosive energy then could move laterally rather than vertically". The prosecutor submitted that it followed from that concession that if the Court accepts that cl 3.3.5 applied to the blast, the timing that was applied meant that there was not a good progressive release of burden. Further, having been prepared to agree with that premise as a matter of logic, the Court should not accept as credible Dr Aimone-Martin's refusal to accept, in line with the ISEE Blasters' Handbook, that as the blast vented into the atmosphere, a large portion of the energy of the blast was lost in air overpressure.
[98]
Defendant's submissions in relation to the timing charge
The defendant referred to conditions L4.1 to L4.4 of the EPL, and submitted that these EPL limit conditions pertaining to airblast overpressure and vibration are also consistent with, and to be "inferred and derived from", the recommended limits for the preservation of human comfort at sensitive receiver sites identified in Appendix J to the Australian Standard (which is partly extracted above at [101] and [104]). The defendant submitted that Appendix J to the Australian Standard is identified as "informative, as distinct from normative", and that it was "significant to understand that distinction". Equally, it was "significant to understand" that the Australian Standard, in addressing recommended levels of vibration and overpressure from blasts, recognises that it is a matter for the regulators in each jurisdiction to determine which recommendations to apply and what limits to set.
It was "quite evident on any reasonable view" of the EPA Act approval and the EPL that in so far as airblast overpressure caused by mine blasting is concerned, these primary regulatory instruments have only adopted the recommended limits in the Australian Standard for the preservation of human comfort at residential receivers. This was submitted to be consistent with the regulatory approach reflected in the Boggabri-Tarrawonga-Maules Creek mining precinct (the BTM complex). The blast management strategy was "prepared jointly by the operators of the three adjacent mines" in the BTM complex. Each of the three mines was independently required under its EPA Act approval to engage in the joint preparation of the strategy, and it was reflected in the terms of the blast management strategy that each of the mines was required to comply with airblast overpressure limits at specified monitoring points representative of residential receivers. In the case of vibration, there was a further limit imposed, namely, the protection of structures.
The defendant referred to the aerial image extracted above at [85] which shows a ring of monitoring points representative of the residential receivers around the collective perimeter of the BTM complex, and submitted that the aerial image "graphically shows" that no regulatory intention could be discerned to meet human comfort levels for airblast within the BTM complex. In so far as there are monitoring points within the BTM complex, these are the respective mine's internal monitors for the protection of structures, and trigger monitors that activate those monitors. It was "not only contrary to the EPL, but the regulatory strategy applying to the BTM Complex to approach the issue of airblast overpressure as if there were required monitoring and human comfort levels within the mines themselves".
[99]
The defendant's competence in carrying out the blast
The defendant submitted that there was no departure by the defendant from the standard of competence reasonably to have been expected of someone in its position in designing and carrying out the blast. The manner in which the blast was designed and implemented was submitted to be "suitable and sufficient" for the purpose for which the blast was to be carried out, including in recognition of the environmental constraints imposed on the defendant. The blast was designed so that the defendant "could properly observe both its duty to ensure the health and safety of its workers and its duty to comply with its environmental obligations", including those imposed under the EPL. The defendant considered, planned and modelled the blast and its potential impact, and followed the processes and procedures developed for safe operations at the mine.
[100]
Alleged failure to put allegations of incompetent design of the blast to the designer, Dr McKenzie
In relation to Dr McKenzie's evidence, the defendant submitted that Dr McKenzie was "well chosen" for the role of designing the blast given his expertise, his previous inspection of the mine, the preparation of his December 2019 report, and his familiarity with the fragmentation problem and how it might be addressed. The defendant submitted that Dr McKenzie addressed the stemming length options first, because of the safety implications concerning flyrock which he modelled to ensure there would be an appropriate clearance radius; he subsequently carried out modelling scenarios involving various timing and stemming scenarios to predict the levels of vibration and airblast overpressure from the blast at the four EPL monitoring points. A primary purpose of the predictive modelling was to give the defendant confidence that the vibration and airblast overpressure levels would not exceed or breach the EPL limits. Dr McKenzie was not asked to use the model to predict vibration or overpressure levels at any other points. As at 14 August 2020, the modelling undertaken by Dr McKenzie was in order to identify scenarios predicted to achieve an airblast overpressure level at the four EPL monitoring points of 119dBL. Subsequently, closer to 17 August 2020, Mr Gomez directed Dr McKenzie to model to a limit of 114dBL to take a "more conservative approach".
As found above at [54], at 10:02pm on 14 August 2020, Dr McKenzie sent an email to Mr Williams, copied to Mr Gomez and Mr Butler, in which he presented 3 options for the defendant's consideration. The defendant submitted that it was "important to understand that this expression of doubt by Dr McKenzie in the third option of his email concerning the ability to reliably model the impacts on the then-available data was a doubt he expressed before he subsequently calibrated his model based upon monitoring data obtained from a [p]revious [b]last".
Likewise, as found above at [64], at 10:47am on 18 August 2020, Dr McKenzie received an email from Mr Butler attaching timing contours. Dr McKenzie responded as follows: "Lee, that looks fine to me ... I have no issues with it." The defendant submitted that Dr McKenzie's email to Mr Butler in response to Mr Butler's email demonstrated that Dr McKenzie was satisfied with the timing based on the modelling and data, that no contrary suggestion was put to him, and that the prosecutor's address which sought to leave open the possibility that Dr McKenzie "meant something more limited invite[d] a reversal of the onus of proof and should be disregarded given this was not put to [Dr] McKenzie".
[101]
Assessment of risk of airblast overpressure at the Boggabri coal mine
In relation to the assessment of risk of airblast overpressure at the Boggabri coal mine, the defendant submitted that interspersed throughout the prosecutor's closing submissions on the timing charge and stemming length charge were submissions relating to the defendant's omission to conduct modelling to predict the airblast overpressure of the blast at the Boggabri coal mine. What was "missing" was "any clear articulation" of what the prosecutor's case was in this regard. The closest the prosecutor's submissions came to putting a clear legal proposition was in recitations of the opinion of Dr Cameron that the blast was not designed in a competent manner because the impact of the airblast overpressure on personnel at the Boggabri coal mine was not considered. If the Court adopts this opinion of Dr Cameron as a submission to the Court as to the legal position in relation to the timing charge and the stemming length charge, the defendant would ask the Court to expressly indicate that position, in which case the defendant submitted as follows:
1. The proposition that the blast was not designed in a competent manner because the impact of the airblast overpressure on personnel at the Boggabri coal mine was not considered must be rejected in relation to both the timing charge and stemming length charge because it was not an allegation made in the timing charge summons or stemming length charge summons.
2. The proposition that in order to achieve a standard of competence in carrying out the blast, the defendant had an obligation to first carry out modelling of the airblast overpressure on an adjoining mine was a "novel and far-reaching proposition, which is not supported by any precedent".
3. The proposition was "unsound in principle" as, if it were true, it would mean that every mine blast carried out by the defendant (and the other two mines in the BTM complex) would have to be the subject of modelling, not just at the modelling points identified in their EPLs, but around the points of the compass, and not just for adjoining mine workers, but also for its own mine workers. The defendant as a licence holder was entitled to certainty as to what monitoring it was required to carry out for airblast overpressure under its licence. It was not required to have monitors for airblast overpressure either on the mine or on adjoining mines. The proposition that in order to achieve a standard of competence in carrying out the blast, the defendant had an obligation to first to carry out modelling of the airblast overpressure on an adjoining mine was "completely contrary to the scheme of the EPL", and condition O1.1 should not be so construed.
4. Even if it were to be assumed that the defendant should have modelled for airblast overpressure at the Boggabri coal mine prior to carrying out the blast, this was "conceptually distinct" and did not bear upon whether the licensed activity was carried out competently.
[102]
Defendant's further submissions in relation to the timing charge
The defendant further referred to the prosecutor's allegation that it did not carry out the blast in a competent manner because it programmed the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m, which allegedly did not provide "good progressive release of burden". In relation to the allegation of failing to "abide" by the requirement in the 5th dot point in cl 3.3.5 of the BLMP, the defendant submitted that it was not alleged that the charges did not detonate in the correct sequence. Given the reliance placed by the prosecutor on the proposition that the blast was a bench blast and not a lifting blast, and the prosecutor's attack on the credibility of Dr Aimone-Martin, the defendant submitted that the Court "will have to make an express finding as to whether or not the subject blast was a bench blast or a lifting blast". The "entirety of the weight of the evidence" upon the issue, save for that of Dr Cameron, supported the finding that it was a lifting blast. [46]
Further, the defendant submitted that "delay timing" allowed progressive release of burden by firing blast holes in staggered timing to allow earlier firing blast holes to move rock so that later firing blast holes can then move the burden rock they release into the holes created by the earlier firing blast holes. There was no dispute that the inter-row timing chosen for the blast was fast. However, as Dr McKenzie pointed out, the blast design did include inter-row delays, and did provide progressive release of burden, leaving only the question of whether the progressive release of burden satisfied the loose concept of being "good". The prosecutor's assertion that the timing design was in contravention of the requirement in the fifth dot point in cl 3.3.5 of the BLMP not only involved a "myopic focus" on those words without a proper consideration of their immediate or broader context, but also "a fundamental misreading" of cl 3.3.5. All of the dot points including the fifth dot point were connected back to the opening words of the clause, namely: "This objective will be met by ensuring…". The objective referred to is the objective of meeting the relevant overpressure and ground vibration criteria. That objective was achieved. It was "nonsensical" to suggest a breach of this clause of the BLMP referable to one of the dot-point measures identified as intended to serve an objective that was met.
[103]
Consideration of, and conclusions in relation to the timing charge
In relation to the timing charge, the alleged manner of contravention of condition O1.1 of the EPL was that the defendant "did not carry out the licensed activities in a competent manner in that it programmed the electronic initiation system for the Blast with a burden relief time of 0.8 - 1.5 ms/m, which did not provide good progressive release of burden as required under section 3.3.5 of the Defendant's Blast Management Plan".
In summary, in relation to the timing charge, I find established beyond reasonable doubt as follows:
1. a decision was made on behalf of the defendant to use fast timing for the blast which was a departure from the standard blasting practice at the mine;
2. the timing used in the blast through electronic initiation resulted in a burden relief time of 0.8-1.5ms/m. The prosecutor submitted, and I find, that the evidence of this fact was not subject to a limitation under s 136 of the Evidence Act. The defendant's expert Dr Aimone-Martin calculated a burden relief time of 0.92ms/m. This was also within the range alleged in the summons;
3. the use of fast timing resulted in a MIC approximately ten times more than conservative and proven levels;
4. no modelling was conducted to the south of the mine, the Boggabri coal mine being located less than 3km to the south and the closest blast monitor (BM3) approximately 7.5km from the blast, contrary to cl 3.1 of the BLMP which specified requirements in relation to the minimisation of the likelihood of significant blast impacts to neighbouring receivers, including by considering appropriate initiation delays and detonation systems. I so find notwithstanding the defendant's argument in closing submissions that it considered the Boggabri coal mine by having a 700m personnel exclusion zone which required that mine (which was notified of the blast) to move any contractors in the northern part of the Boggabri coal mine;
5. concerns were raised by the shotfirer, Mr Welch, about the use of fast timing when tying up the shot on 19 August 2020;
6. cl 3.3.5 of the BLMP concerning air vibrations (overpressure) management applies to all blasts conducted at the mine;
7. irrespective of whether the blast is properly characterised as a lifting blast so that what was required was good vertical release, rather than good progressive burden release, the fast timing used did not provide for this;
8. the use of fast timing did not provide for good progressive release of burden and resulted in a MIC approximately ten times more than conservative and proven levels and in high levels of noise and airblast overpressure;
9. Dr Aimone-Martin accepted that in expressing her opinions in relation to the timing charge, she gave no consideration as to whether there were likely to be workers present at the Boggabri coal mine at the time of the blast, and that "Yes, of course" the likely distance of persons from the blast was a relevant matter to be taken into consideration; and
10. in relation to the third option identified by Dr McKenzie of "3 m stemming and fast timing, and use the result as a learning opportunity, since I have doubt about the ability to reliably model the impacts on the data I have available", Dr Aimone-Martin accepted that, as at 10:02pm on 14 August 2020, the third option involved a learning opportunity.
[104]
The stemming length charge: alleged offence against s 64(1) of the POEO Act
As with the timing charge, the stemming length charge alleges that between 4 and 20 August 2020, the defendant committed an offence against s 64(1) of the POEO Act by contravening condition O1.1 of the EPL. In relation to the stemming length charge, the alleged manner of contravention of condition O1.1 of the EPL was that the defendant "did not carry out licensed activities in a competent manner because it designed the Blast with a stemming length for the blast holes of 3.0m, which deviated from the [design standard]". In other words, the prosecutor alleges that the defendant contravened condition O1.1 of the EPL by failing to carry out the blast in a competent manner; specifically, that the defendant's utilisation of a 3.0m stemming length for the blast holes deviated from the defendant's design standard which specified a stemming length for the blast holes of 3.5m.
Dr Aimone-Martin's opinion was that there was no failure to carry out the blast in a competent manner by shortening the stemming length to 3.0m because the change in stemming length was properly planned and documented. In her view, it was appropriate to address the caprock problem the mine had been facing, and the change from 3.5m to 3.0m stemming was appropriate in that it was selected "to improve rock fragmentation and the productivity and safety of equipment and mine workers in the removal of blasted rock".
[105]
Prosecutor's submissions in relation to the stemming length charge
The prosecutor referred to Dr Cameron's evidence that the blast was not designed in a competent manner because the changes made to the stemming length did not comply with the BLMP for managing airblast overpressure. Specifically, Dr Cameron's evidence was that "the minimum requirements for a blast to be designed in a competent manner are, firstly, to consider the hazards/risks for all persons potentially impacted by the blast, and secondly, follow the processes and procedures developed for safe operations at the mine".
The prosecutor also referred to Dr Cameron's evidence that the stemming length of 3.0m utilised in the blast involved a 14% reduction in stemming length compared to the design standard of 3.5m, and therefore 14% less material confining the top of the explosives, and to his reliance on the rule of thumb commonly used for calculating stemming length in the ISEE Blasters' Handbook and Orica's Pocket Blast Guide that stemming length equals 20 to 30 times blast hole diameter. Applying this rule of thumb, 20 times the blast hole diameter of 0.229m for the blast was approximately 4.6m, indicating that the design standard stemming length of 3.5m (15.3 x blast hole diameter) was already less than that normally used and, therefore, a further reduction of this length by 14% was a significant amount.
Dr Cameron's opinion was that the blast was not designed in a competent manner also because the impact of airblast overpressure on personnel at the Boggabri coal mine was not considered, consistent with his conclusions in relation to the timing charge.
The prosecutor submitted that Dr Aimone-Martin's opinion that the change from 3.5m to 3.0m stemming was appropriate was premised on the fact that the deviation in the stemming length from the design standard was "properly documented". However, it was apparent from the documentary evidence that the change in stemming length was not properly documented. In particular, there was a failure to complete the drill and blast design checklist (see [113] above). In cross-examination, Dr Aimone-Martin accepted that if the change in stemming length was not properly documented, this would change her opinion. Dr Aimone-Martin was asked a series of questions in relation to the documentation of the stemming length charge, and agreed that the fact the drill and blast design checklist was not completed means the drill and blast design procedure had not been "managed completely" (see [230]-[231] above).
[106]
Defendant's submissions in relation to the stemming length charge
It was not in contest that the 3.0m stemming length for the blast deviated from the design standard. However, that did "not bespeak of any lack of competence in making a considered and deliberate decision to vary this parameter referable to the standard stemming height". The defendant referred to the evidence of Dr Cameron where he accepted that if there was a particular problem which the defendant wished to address in design, it might sensibly make a decision to alter a parameter compared to a design standard. Further, Dr Cameron gave evidence in response to a proposition that deviation from a standard is not in and of itself indicative of competence or incompetence, that: "it depends, I guess, on what the basis for the deviation was. This was their procedure".
The defendant also referred to Dr McKenzie's evidence that the design standard can be departed from when the "whole blast is being done differently". In this case, the basis for the deviation was the work health and safety concern which had been "brought to the fore" on the Herndale seam which Dr McKenzie had been retained to address. Not only was the blast carefully designed with a 3.0m stemming height, but the variation from the standard was documented to record the change in this design parameter. Mr Williams prepared documentation recording the alteration of the stemming length from 3.5m to 3.0m. The change to 3.0m stemming was appropriate in line with the recommendation of Dr McKenzie to fragment the hard caprock along the Herndale seam.
Further, the defendant submitted, the concept of reducing stemming height (or length) to address fragmentation was not a new concept. In his 2019 report, Dr McKenzie had recommended stemming length in the range of 3.0m to 3.5m for hard caprock areas. When he first recommended the reduction in stemming length, he stated that "stemming lengths must be minimised, consistent with maintaining flyrock safety". According to Dr Aimone-Martin, this modification was appropriate to improve fragmentation based on the geological conditions of the Herndale seam, and to facilitate improved productivity and safety. Dr McKenzie modelled the blast based on the 3.0m stemming length and communicated these results which were within the defendant's regulatory and EPL parameters (see [66] above). The stemming length of 3.0m was a considered variation from the 3.5m standard, recorded as such on the drill and blast design checklist.
[107]
Consideration of, and conclusions in relation to the stemming length charge
I find established beyond reasonable doubt as follows in relation to the stemming length charge:
1. a decision was made on behalf of the defendant to use reduced stemming for the blast which was a departure from the design standard which specified a stemming length of 3.5m and from standard blasting practice at the mine;
2. the utilisation of a stemming length of 3.0m involved a reduction in the stemming length of 3.5m specified in the design standard, and hence a 14% reduction in stemming length and 14% less material containing the top of the explosives;
3. as opined by Dr Cameron, the approved stemming length of 3.5m was already less than that normally used, and a further reduction of this length by 14% was a significant amount;
4. the utilisation of a stemming length of 3.0m involved a reduction in stemming length from the 4.0m used in the previous blast on 7 August 2020, and hence a 25% reduction in stemming which, Dr Aimone-Martin agreed, was a "significant change";
5. as agreed by Dr Aimone-Martin, the blast ratio was significantly less than that recommended in the ISEE Blasters' Handbook (and Orica's Pocket Blast Guide), namely, 13.1 compared to the recommended blast ratio of between 20 and 30;
6. as in relation to the timing charge, no modelling was conducted to the south of the mine, the Boggabri coal mine being located less than 3km to the south, and the closest blast monitor (BM3) being located approximately 7.5km from the blast, contrary to cl 3.1 of the BLMP which specified requirements in relation to the minimisation of the likelihood of significant blast impacts to neighbouring receivers, including by considering the adequacy of stemming; and
7. the change in stemming length was not properly documented, the drill and blast design checklist (extracted above at [113]) not having been completed contrary to section 3.1 of the planning, design and record keeping procedure.
In particular, in relation to the stemming length charge, Dr Aimone-Martin's evidence was that if the stemming length design change to 3.0m was in fact not properly documented, that would change her opinion, and that in order for the blast design to be described as "competent", it was necessary for the drill and blast design checklist to be signed off appropriately. She accepted that the date in the drill and blast design checklist was blank, and that the date was important in relation to each of the matters of geology, mine planning, and blast engineering because of the iterations that the design was going through with Dr McKenzie. Further, she agreed that in the absence of sign off by the geology mine planning and blast engineer, the stemming length charge was not properly documented, "if this was required". She ultimately agreed that the drill and blast design checklist was not completed, demonstrating that the drill and blast design procedure was not "formally managed".
[108]
The overloading charge: alleged offence against s 64(1) of the POEO Act
In relation to the overloading charge, the alleged manner of contravention of condition O1.1 of the EPL was that the defendant "did not carry out the licensed activities in a competent manner because it overloaded approximately 19% of blast holes for the Blast with more than 10% of the amount of explosives prescribed in the design for the Blast, which was in contravention of the Defendant's procedure for loading and stemming blast holes (WHC-PRO-OC-LOADING AND STEMMING)".
As with the timing charge and stemming length charge, the overloading charge alleges that between 4 and 20 August 2020, the defendant breached s 64(1) of the POEO Act by contravening condition O1.1 of the EPL. Specifically, the prosecutor alleges that the defendant did not carry out the licensed activities in a competent manner, thereby failing to comply with condition O1.1 of the EPL, because it overloaded approximately 19% of the blast holes with more than 10% of the amount of explosives prescribed in Dr McKenzie's design for the blast, in contravention of the loading and stemming blast holes procedure.
The defendant's planning, design and record keeping procedure provided at section 3.2.2 that "[t]he design objective is to deliver a drill pattern design within 10% of the target design parameters". Section 3.5 of the loading and stemming blast holes procedure, and section 3.4.2 of the planning, design and record keeping procedure, provided that the loading sheets should contain a maximum kg of explosives per hole. It was common ground that the amount of explosives loaded for the blast was more than 10% of the amount prescribed in the loading and stemming blast holes procedure, and that 19% of the holes were loaded with at least 10% more explosives than in Dr McKenzie's blast design.
Dr Aimone-Martin carried out the same calculations as Dr Cameron based on the loading sheets and came to the same conclusion that "19% of the holes with loading data were loaded with more explosive charge weight than shown in [Dr] McKenzie's loading plans".
[109]
Prosecutor's submissions in relation to the overloading charge
[110]
Dr Cameron's evidence in relation to the overloading charge
The prosecutor relied on the analysis undertaken by Dr Cameron of the load sheet data from the blast in which he compared the designed amount of explosives to be loaded into a blast hole with the actual amount loaded into the individual blast holes. Of the 1,000 blast holes with loading data, Dr Cameron found that 191 holes, or 19%, contained at least 10% more explosives than designed, and of those 191 holes, 33 holes contained more than 20% of the designed amount.
Dr Cameron explained why, on a "proper and fair construction" of section 3.5 of the loading and stemming blast holes procedure, there was not to be more than a 10% variation in the amount of explosives loaded into each blast hole. Dr Cameron rejected the proposition that the charge weight loaded into the blast holes was not a design parameter because the explosive charge weight for each hole in a blast pattern was calculated based on the measured hole depth, explosive parameters, stemming length and hole diameter, then entered into charge sheets by the drill and blast engineers. That was because an overloaded hole creates a safety issue.
The prosecutor referred to Dr Cameron's evidence in cross-examination, where he said:
A. … there are various reasons it could be not coming out and if you get extra explosives in the hole, it's, it's a safety issue. So, you're adding extra explosives and you then have the potential you don't know where the explosive is going, you have the potential of causing more fly rock or noise or things like that.
Q. Well, the issue of fly rock was quite carefully modelled, wasn't it, by Dr McKenzie before the subject blast, you accept that, don't you?
A. Assuming ideal conditions, yes. What we are getting is, is non-ideal conditions so if there happened to be a [cavern] or something there that was getting full of explosives, then that is something that, that has potential for a safety issue.
The prosecutor also referred to Dr Cameron's evidence in re-examination, reproduced above at [153] in relation to the hypothetical example he was given. Dr Cameron explained:
… the discussion was about the hole not coming up to the correct level and explosives - the quantity of explosives had been loaded into it, and then if too much explosive goes into the hole, or extra goes into the hole, then the possibility of the surface breaking up because there is extra explosive, excessively breaking up, and that adds to the - that's a safety issue in terms of the flyrock and air blasting.
[111]
Dr Aimone-Martin's evidence in relation to the overloading charge
The prosecutor referred to Dr Aimone-Martin's acceptance, in cross-examination, that there were three steps in the logic of her opinion as to whether the blast was carried out in a competent manner by reason of the alleged overloading of 19% of the blast holes with more than 10% of the explosives prescribed by the blast design; namely (1) that the 10% variance did not apply to the loaded charge weights of each individual hole; (2) that the 10% variance applied to the design of the whole of the blast (and not he design of each hole); and (3) that the variations in the weight of each hole arose from matters such as normal wear and tear of equipment and the presence of "caverns".
The prosecutor also referred to Dr Aimone-Martin's acceptance in cross-examination that the potential danger arising from overloading a hole can be a danger to the environment. When taken to the ISEE Blasters' Handbook, Dr Aimone-Martin accepted that in any blast there is a conflicting requirement between, on the one hand, the benefit to the mine of providing large quantities of well-fragmented rock that can be excavated and processed and, on the other hand, minimising damage to the environment. Dr Aimone-Martin accepted that a blast needs to deal with that conflicting requirement in order for the blast to be carried out in a competent manner. She also accepted that the loading and stemming blast holes procedure should be approached in a manner that would promote the paragraphs in section 4.1 of the Australian Standard.
In relation to the first two steps in Dr Aimone-Martin's logic concerning the overloading charge, her written evidence was that it is only variations in design parameters and most importantly, powder factor, that must remain within the 10% variance. Her view was that in this case, the powder factor remained well below the 10% allowance. In this respect, Dr Aimone-Martin and Dr Cameron fundamentally disagreed on whether the concept of "overloaded blastholes", referring to the charge weight loaded into the blast holes, was a design parameter subject to the 10% variation as required in the mine's documentation.
In order to explore the approach taken by Dr Aimone-Martin, the prosecutor provided her with a hypothetical example in the form reproduced above at [236]. Dr Aimone-Martin's answers in cross-examination by reference to this hypothetical are reproduced above at [237]. The prosecutor submitted, and I find, that in the course of cross-examination by reference to the hypothetical example, it became apparent that the difference in approaches between the experts was that Dr Cameron's approach was to look at each hole and to draw a conclusion based on each hole, whereas Dr Aimone-Martin, having calculated a percentage variance in explosive loaded, averaged that variance across all of the holes in the blast. The prosecutor submitted that having admitted that there can be overloading of a single hole and that overloading of a single hole can cause damage to the environment, the approach taken by Dr Aimone-Martin in averaging the variance across all the holes did not take account of these facts. The prosecutor submitted that it "cannot be that is how the defendant's own procedures were intended to be interpreted".
[112]
Defendant's submissions in relation to the overloading charge
The defendant submitted that the point of distinction between the experts in relation to the overloading charge related to the meaning of overloading, including whether the concept is "amenable to a single meaning". Dr Cameron, the defendant submitted, accepted that his view was unsupported by any literature, and opined that overloading relates to individual holes, rather than the blast as a whole. To convict on this charge, the Court must be satisfied beyond reasonable doubt that Dr Cameron's "theory or view" as to the meaning of overloading is correct. In the absence of any supportive literature or other evidence, that was not open to the Court. Put another way, Dr Cameron failed "to consider the realities of geological conditions in preparing and filling blast holes, or the appropriate criteria which the defendant were required to comply in filling the blast holes and carrying out the blast".
Dr Cameron accepted that he had not included information in his report which pointed out that holes were underloaded, as opposed to overloaded. If he had included the calculations he says he carried out in his report, the reader would have been aware of that fact. Dr Cameron "meekly accepted" that it is possible that a reader of the report would be left with an "incomplete or inaccurate impression".
The defendant referred to section 3.8.1 of the planning, design and record keeping procedure which provides in relation to the charge design of a blast that: The allowable variance between design and actual powder factor should be indicated on the relevant Charge Design. Variance greater than 10% should be reviewed by D&B Engineer and D&B Manager. The defendant noted that the loading and stemming blast holes procedure does not refer to a 10% variance in actual powder factor or design parameters although, it submitted, the prosecutor relied on this procedure in support of the overloading charge. The defendant submitted that Dr Cameron "reluctantly, ultimately accepted" that there was no design powder factor in relation to each individual hole, as opposed to the entirety of the blast. In any event, the blast holes for the blast were loaded in accordance with the loading and stemming holes procedure.
Here, the defendant submitted, the aggregate quantity of explosive for all holes combined conformed to the blast design, and therefore the blast design was appropriately implemented, accepting that explosives loaded into blast holes can vary on a hole-by-hole basis. This view was supported by Mr Tapan Goswami of Blast Outcome Services in his September 2020 investigation into the blast prepared for Whitehaven Coal. In his report, Mr Goswami concluded that there was some variation between the design and actual kg of explosives in many blast holes, however that this was "not uncommon". This view was submitted to be consistent with that of Mr Welch who shot the subject blast, as well as that of Mr Gomez. (Mr Goswami was not called as a witness, and his conclusions were not tested).
[113]
Consideration of, and conclusions in relation to the overloading charge
In relation to the overloading charge, I find that the prosecutor has established beyond reasonable doubt that the defendant did not carry out the licensed activities in a competent manner and thereby breached s 64(1) of the POEO Act by contravening condition O1.1 of the EPL. I find established beyond reasonable doubt that in overloading approximately 19% of the blast holes with more than 10% of the amount of explosives prescribed in the design for the blast, contrary to the loading and stemming blast holes procedure, the defendant did not carry out the licensed activities in a competent manner. Such overloading was not "fitting, suitable or sufficient for the purpose" having regard to the possible environmental consequences.
In particular, I find established beyond reasonable doubt as follows:
1. the defendant's planning, design and record keeping procedure provided for the design objective "to define a drill pattern design within 10% of the target design parameters";
2. the amount of explosives loaded for the blast was more than 10% of the amount prescribed in the defendant's loading and stemming blast holes procedure;
3. as Dr Aimone-Martin accepted, the loading and stemming blast holes procedure should be approached in a manner that would promote the paragraphs in section 4.1 of the Australian Standard. I find that it did not;
4. 19% of the holes were loaded with at least more than 10% of explosives than provided in the blast design;
5. of the 191 holes which contained at least 10% more explosives than designed, 33 holes contained more than 20% of the amount provided in the blast design;
6. as opined by Dr Cameron, an overloaded hole creates a safety issue in terms of flyrock and "air blasting" and, as opined by Dr Cameron, and accepted by Dr Aimone-Martin, a potential danger to the environment;
7. practical steps can be taken to ensure that the weight of explosives in a particular hole is kept consistent with the design weight for the hole, it being achievable and common practice because the bulk explosives delivery trucks have measurement systems that track and control the amount of explosives loaded in each hole, and have load sheets with the design weight to be loaded in each hole;
8. whilst there can, as opined by Dr Aimone-Martin, be variations in loading values, that does not address the practical steps available to be taken to track and control the amount of explosives loaded in each hole;
9. as in relation to the timing charge and stemming length charge, no modelling was conducted to the south of the mine, the Boggabri coal mine being located less than 3km to the south, and the closest blast monitor (BM3) approximately 7.5km from the blast, contrary to cl 3.1 of the BLMP which specified requirements in relation to the minimisation of the likelihood of significant blast impacts to neighbouring receivers, including by considering blast hole loading procedures;
10. whilst as submitted by the defendant, it is relevant to consider geological conditions, variations in ground surface elevation and drilling rig performance in preparing and filling blast holes, however again that does not address the practical steps available to be taken to track and control the amount of explosives loaded in each hole; and
11. it was available to the blast crew to consider the quantities specified in the loading sheets, and they did not.
[114]
The emission of noise charge: alleged offence against s 140(1) of the POEO Act
The particulars of the emission of noise charge which alleges a contravention of s 140(1) of the POEO Act are set out above at [15]. The particulars specify the "materials" as 896,256kg of explosives, consisting of XL60-100 and XLOAD70-110 (the explosives). The alleged manner of dealing is that the explosives were dealt with at the premises during the blast by (1) stemming blast holes loaded with explosives to 3.0m; and (2) detonating the explosives using fast timing of the electronic initiation system. The manner of dealing with the explosives is alleged not to have been proper and efficient as it resulted in the dispersion of excessive explosive energy upwards into the atmosphere, thereby reducing the explosive energy of the blast directed towards the breakup of caprock or overburden that was the intended purpose of the dealing with the explosives. The particulars allege that the manner of dealing with the explosives resulted in an explosion that caused the emission of noise from the premises in the form of sound and vibration resulting from airblast overpressure.
In relation to the emission of noise charge, the offence against s 140(1) of the POEO Act requires proof of the following elements:
1. the occupier of the premises (element one);
2. deals with materials in or on the premises (element two);
3. the dealing with the materials caused the emission of noise from the premises (element three); and
4. the noise so caused, or any part of it, being caused by the occupier's failure to deal with the materials in a proper and efficient manner (element four).
Plainly, a charge under s 140(1) of the POEO Act is not a charge in relation to a breach of a condition of an EPL. Nor does s 140 include a statutory defence of an authority conferred by an EPL, nor does any other section in Part 5.5 of the POEO Act titled "Noise pollution" provide a defence to an offence against s 140(1). This is in contrast to s 120 (offence of water pollution) for which a statutory defence in s 122(1) provides that it is a defence to proceedings if "(a) the pollution was regulated by an environment protection licence held by the person or another person, and (b) the conditions to which that licence was subject relating to the pollution of waters were not contravened".
[115]
The proper construction of s 140(1) of the POEO Act, and the phrase "proper and efficient manner"
Neither of the parties nor the Court's research identified any prosecution in relation to an offence against s 140(1). The provision was referred to by Pepper J in civil enforcement proceedings in McCallum v Sandercock (McCallum v Sandercock), [48] although her Honour did not consider the construction of the expression.
[116]
Prosecutor's submissions in relation to the proper construction of s 140(1)
The prosecutor, noting that there is no definition in the POEO Act of the expression "proper and efficient manner", submitted that it must be construed using the ordinary principles of statutory interpretation. The prosecutor submitted that there is an "interconnectivity" between each of the elements of s 140(1): it is an offence if materials are dealt with in a way that is not proper and efficient, and those dealings caused the emission of noise from the premises. The phrase "proper and efficient" in the context of s 140(1) should be best considered as a hendiadys, expressing a single idea in the one phrase: McCallum v Sandercock at [157] (Pepper J). Further, the prosecutor submitted that the expression "proper and efficient" must be considered in the context of the statutory provision; that is, in the context of "deal[ing]" with "materials" which are both terms defined in s 140(2). What it means to deal with materials in a proper and efficient manner depends on the materials that are being used, how they are being dealt with, and the facts and circumstances in which they are being dealt with.
The prosecutor further submitted that the construction of s 140(1) must occur against the background of the objects of the POEO Act which include "to protect, restore and enhance the quality of the environment in New South Wales" (s 3(a)), and to "reduce risks to human health and prevent the degradation of the environment by the use of mechanisms that promote", inter alia, "pollution prevention and cleaner production" (s 3(d)(i)), "the reduction to harmless levels of the discharge of substances likely to cause harm to the environment" (s 3(d)(ii)), and "the making of progressive environmental improvements, including the reduction of pollution at source" (s 3(d)(iv)).
The prosecutor referred to Bartter (No 3) where Duggan J considered the construction of a condition in an EPL which was in the following terms: "O2.1 All plant and equipment installed at the premises or used in connection with the licensed activity: (a) must be maintained in a proper and efficient condition; and (b) must be operated in a proper and efficient manner." Duggan J construed the phrase "a proper and efficient condition" as "to keep something in existence in a state which enables it to serve the purpose for which it exists" at [45].
[117]
Defendant's submissions in relation to the proper construction of s 140(1)
The defendant submitted that the question of whether the defendant dealt with the explosives in a proper and efficient manner is to be determined by reference to the text of s 140(1) and the context of the POEO Act. Whether the explosives were dealt with in a proper and efficient manner is not to be determined at large, "but rather by considering whether the defendant failed to deal with the explosives in a proper and efficient manner according to the possible environmental consequences of the act or omission in question".
[118]
Conclusion in relation to the proper construction of s 140(1) of the POEO Act
As submitted by the defendant, the question of whether the defendant dealt with the explosives in a proper and efficient manner is to be determined by reference to the text of s 140(1) and the context of the POEO Act, and by considering the possible environmental consequences of the act or omission in question: Genkem at 41C-E (Gleeson CJ); cited with approval in Bartter CCA at [21] (Basten JA) (Davies and Dhanji JJ agreeing).
I find, guided by Genkem and Bartter CCA (both cases dealing with the construction of conditions of licences and not a statutory provision such as s 140(1)), that the phrase "proper and efficient" in s 140(1) must be understood as referring to dealing with materials in or on premises in such a manner as to cause the emission of noise from the premises where the noise so caused, or any part of it, is caused by the occupier's failure to deal with those materials in a proper and efficient manner, having regard to the possible environmental consequences arising from a failure to deal with the materials in such a way as to minimise or avoid those risks.
I do not interpret s 140(1) as having "any sort of implied exception or defence that is based upon what is allowed under the conditions of the EPL". I find, as submitted by the prosecutor, that the limits placed upon s 140(1), by its terms, are that there be an emission of noise from the premises, and that the emission of noise must be caused by the failure to deal with the materials in a proper and efficient manner. It is no defence to an offence against s 140(1) that the emission of noise was in accordance with the airblast overpressure and vibration limits set out in the EPL.
[119]
Element one: was the defendant the occupier of the premises
In the Dictionary to the POEO Act, "occupier of premises" is defined as the person who has the management or control of the premises. It was uncontroversial that the defendant was the occupier of the mine at all relevant times. I find established beyond reasonable doubt that the defendant was the occupier of the premises at all relevant times.
[120]
Element two: did the defendant deal with materials in or on the premises
The defendant accepted that the explosives nominated in the emission of noise charge summons as the "materials" are "materials" within the meaning of s 140(1). However, it submitted that there were no particulars concerning any other "materials", and that the stemming materials were not particularised as part of the charge. The "manner of dealing" with those materials was submitted to be "expressly" a complaint about the utilisation of 3.0m stemming and fast timing with electronic initiation, the prosecutor alleging that this manner of dealing with the explosives resulted in the dispersion of excessive explosive energy upwards into the atmosphere, "thereby reducing the explosive energy of the blast directed towards the breaking of caprock or overburden that was the intended purpose of dealing with the [e]xplosives". Accordingly, the defendant submitted, the complaint the subject of the emission of noise charge was a complaint about the design of the blast in relation to stemming and timing, and that once "it is understood that this complaint about 3.0m stemming and fast timing is a complaint about the design of the blast, it may be discerned that the elements of s 140(1) of the POEO Act are inapposite for the complaint".
The defendant also relied on its submissions in relation to the timing charge and the stemming length charge in answer to the emission of noise charge, and submitted that designing a blast to incorporate 3.0m stemming and fast timing cannot amount to "dealing" with materials. To "deal" with materials is to process, handle, move, store or dispose of the materials. The prosecutor had "manifestly failed" to articulate which manner of "dealing" with the explosives the emission of noise charge concerns. The complaint about the use of the 3.0m stemming length and fast timing could not "sensibly be said" to be about the processing of the explosives. Rather, it was a complaint about the design parameters of the blast concerning stemming height and timing.
I find established beyond reasonable doubt that the explosives nominated in the emission of noise charge are "materials" within the meaning of s 140(1), and that in stemming the blast holes with the materials nominated in the emission of noise charge using a stemming length of 3.0m, and in detonating those materials using fast timing, the defendant was "dealing" with materials within the meaning of s 140(1). I find established beyond reasonable doubt that the defendant dealt with the materials in or on the premises, and that as with the defendant's submission in relation to the blast design being separate from the licensed activity (see my finding above at [348(6)]), it is likewise contrived and unrealistic to suggest that "to deal with" materials is separate from and excludes the blast design process.
[121]
Element three: did the dealing with the materials cause the emission of noise from the premises?
The Dictionary to the POEO Act defines "noise" to include "sound and vibration". I am satisfied, as submitted by the prosecutor, that the "sound and vibration" resulting from the airblast overpressure and vibration that was recorded following the blast was "noise" for the purposes of the POEO Act.
In relation to element three of the emission of noise charge, the defendant submitted that an "insurmountable problem" for the prosecutor was that it could only be the firing of the blast that could be said to have created (or caused) the emission of noise. Again, the complaint the subject of the emission of noise charge was said to be a complaint about the design of the blast, and the design of the blast did not cause the emission of noise. I have addressed what I consider be the artificiality of that submission above at [467].
I find established beyond reasonable doubt that the vibration and airblast overpressure caused by the blast was "noise" within the meaning of the POEO Act, and that there was an emission of noise from the premises in that the measurements of sound and vibration were recorded outside the mine. I find established beyond reasonable doubt that the emission of noise was caused by the defendant's dealing with the explosives in stemming the blast holes with the explosives and in detonating the explosives.
[122]
Element four: Whether the noise so caused, or any part of it, was caused by the defendant's failure to deal with the materials in a proper and efficient manner
In relation to the offence against s 140(1), as submitted by the prosecutor, "the real question" is whether the prosecutor can prove that the emission of noise was caused by the occupier's failure to deal with the materials in a "proper and efficient manner".
[123]
Prosecutor's submissions in relation to whether the noise so caused, or any part of it, was caused by the defendant's failure to deal with the materials in a proper and efficient manner
The prosecutor relied on Dr Cameron's evidence in which he explained that the combination of short stemming and fast timing resulted in a release of explosive energy in the form of airblast overpressure which caused the emission of noise. Dr Cameron's evidence was that when explosives are detonated, they release energy in the form of a shock pulse and very high-pressure gases, stemming material holding the high-pressure gases in the rock mass for a period of time allowing the gas to break the rock. Dr Cameron opined that the 14% reduction in the stemming length that occurred when the stemming was reduced from 3.5m to 3.0m meant that there was less material confining the top of the explosives resulting in less time for the high-pressure gases to do work on the rock prior to venting into the air. When combined with the fast timing, there was a premature release in explosive energy into the atmosphere causing a large airblast to radiate outwards. It also gave rise to a large waste of explosive energy. That is why, Dr Cameron opined, the emission of noise was caused by the defendant's failure to deal with the materials in a proper and efficient manner.
The prosecutor referred to Dr Aimone-Martin's opinion that the explosive materials were handled in a "proper and efficient manner" because "the blast was designed with a 3.0m stem length and fast delay timing achieved the stated objectives of improved fragmentation, efficient and safe digging without damaging equipment and by protecting workers, and without exceeding airblast overpressure and vibration limits at the monitoring locations established in [the EPL]". The prosecutor referred to and relied on Dr Cameron's three reasons for rejecting Dr Aimone-Martin's opinion, namely that:
1. the design did not meet an overriding provision of the Australian Standard (the first paragraph of section 4.1) because no consideration was given to the impact on personnel at the Boggabri coal mine;
2. the design resulted in high levels of airblast overpressure due to the sudden movement of the surface of the blast and the release of high-pressure gases, demonstrating that the design did not conform to the objective in the BLMP to "[e]nsure that operational blast vibration and overpressure from activities associated with the [mine] are minimised"; and
3. the early release of high-pressure gases is a waste of explosive energy because it is not moving and fragmenting the rock mass.
[124]
Defendant's submissions in relation to whether the noise so caused, or any part of it, was caused by the defendant's failure to deal with the materials in a proper and efficient manner
The defendant submitted that the prosecutor's submission that Dr Aimone-Martin asked herself and answered the wrong question should be rejected because the question forms an element of the offence charged (namely "Did [the defendant] deal with materials (the Explosives as defined in the Summons 2021/234558 at paragraph a of the Particulars) in a proper and efficient manner?").
The defendant submitted that the emission of noise charge, as particularised, recognises that the purpose of the blast was to break the caprock or overburden, and that proof of the charge is dependent on the proposition that this fragmentation purpose was not achieved. However, the "uncontroverted" evidence, accepted by Dr Cameron, was that the blast achieved the objective or breaking the caprock. In designing the blast, the defendant, in consultation with Dr McKenzie, had regard to:
1. the expected vibration and overpressure impact of the blast at the blast monitoring sites, recorded in the drill and blast design checklist as having been completed;
2. the presence of a biodiversity corridor near the mine which led to the inclusion of an additional delay for the last five rows of shot to avoid any material being thrown into the biodiversity zone (referring to Dr McKenzie's record of interview);
3. maximising fragmentation of the caprock to ensure that it could be safely handled and removed from the mine by equipment and personnel; and
4. ensuring compliance with "the EPA operation and regulating conditions" (again referring to Dr McKenzie's record of interview).
Between 14 and 18 August 2020, Dr McKenzie modelled the overpressure for the blast at each of the EPL monitoring points BM1 to BM4 using Paradigm Optimization Software to establish the optimal timing solution to minimise overpressure and vibrations, while optimising fragmentation. The modelling of ground vibrations at the monitoring locations used "a traditional linear regression model and power curve fit to data from past blasts".
The defendant submitted that if opting for the design elements of 3.0m stemming and fast timing with electronic initiation constitutes "dealing" with the explosives, then the planning, and modelling undertaken by the defendant and Dr McKenzie demonstrated, as opined by Dr Aimone-Martin, that the defendant dealt with the explosives in a proper and efficient manner.
[125]
Consideration of, and conclusions in relation to the emission of noise charge
In relation to the emission of noise charge, it is true that Dr Cameron agreed that the objectives of the improvement of fragmentation and compliance within the limits for noise at the monitoring locations were achieved. Dr Cameron also accepted that he did not have or profess to have any medical qualifications or qualifications as an acoustic engineer, and that he has no expertise in relation to the assessment of the level at which it might be expected that humans would be discomforted by noise.
However, I find established beyond reasonable doubt each of the elements of the emission of noise charge.
1. I have found that the defendant was the occupier of the premises at all relevant times.
2. I have found that the explosives particularised in the emission of noise charge are materials within the meaning of s 140(1) of the POEO Act, and that those materials were dealt with in or on the premises.
3. I have found that the dealing with the materials caused the emission of noise from the premises. The noise so emitted was registered or heard at the EPL monitoring points, as well as at the Coomalagah monitor, the Tarrawonga monitor, the Boggabri trigger unit, Wilberoi East, Goonbri East, by Mr Byrnes and Ms Severin at the Boggabri coal mine, and by Mr Kereopa, Ms Louis, Ms Druce and Ms Westlake at their respective private residences.
4. I find established beyond reasonable doubt that the emission of noise so caused was caused by the defendant's failure to deal with the materials in a proper and efficient manner for the following reasons:
1. The manner of dealing with the explosives did not meet section 4.1 of the Australian Standard which requires that all blasts shall be planned and designed to achieve the required outcome with first consideration by the defendant being the protection of persons, property and the environment, and that before the commencement of any blasting operation an investigation of the site and its environs shall be carried out, identifying any potential hazards/risks. There was no consideration of the safety of persons at the Boggabri coal mine where personnel were less than 3000m from the blast and where an airblast overpressure level of 135.6dBL was recorded at the Boggabri trigger unit, or at the Tarrawonga monitor or at the Coomalagah monitor, a sensitive site located approximately 12.5km from the blast, at which an exceedance of the blast noise limit of 120dBL provided for in condition 18 of the EPA Act approval (namely, 125.4dBL) was recorded (see Dr Aimone-Martin's graph reproduced at [219] above and the table at [288]).
2. As I have found in relation to the timing charge, stemming length charge and overloading charge, no modelling was conducted to the south of the mine, the Boggabri coal mine being located less than 3km to the south, and the closest blast monitor (BM3) being located approximately 7.5km from the blast, contrary to cl 3.1 of the BLMP which specified requirements in relation to the minimisation of the likelihood of significant blast impacts to neighbouring receivers including by considering expected offsite vibration levels.
3. Contrary to the defendant's submission, I do not accept that the complaint the subject of the emission of noise charge ought be characterised as a complaint about the design of the blast. The complaint concerns the manner of dealing with the materials in or on the premises, here relevantly by handling the explosives in utilising 3.0m stemming and fast timing.
4. Further, I find that the manner of dealing with the materials resulted in high levels of airblast overpressure due to the sudden movement of the surface of the blast and the release of high-pressure gases. This does not conform with the objective in cl 1.4 of the BLMP to ensure that operational blast vibration and overpressure from activities associated with the mine are minimised.
5. The defendant's expert Dr Aimone-Martin was not directed to the language of s 140(1) of the POEO Act. Further, her evidence generally in relation to the emission of noise charge was unforthcoming and unhelpful. In particular, her evidence in relation to the weather conditions at the time of the blast was contradictory and unclear. I do not accept the atmospheric conditions which prevailed on 20 August 2020 as relevant to the emission of noise charge. Logically, as the prosecutor submitted, as the blast was called off on 19 August 2020 due to poor atmospheric conditions, it also ought to have been called off on 20 August 2020 if Dr Aimone-Martin's opinion in relation to the significance of atmospheric conditions on 20 August 2020 were to be accepted.
6. That breaking the caprock or overburden was achieved on 20 August 2020 is no defence to the allegation that the defendant dealt with the explosives in such a manner as to cause the emission of noise from the premises and that the noise so caused or any part of it was caused by the occupier's failure to deal with the explosives in a proper and efficient manner. There is a myriad of ways in which the breaking of caprock or overburden can be achieved in such a manner as to cause the emission of noise, other than in a proper and efficient manner.
7. Nor do I accept as sensible the defendant's submission that the prosecutor could not prove that the noise in the form of sound and vibrations resulting from airblast overpressure was caused by the 3.0m stemming and the fast timing. I have found above at [484(3)] that dealing with the explosives caused the emission of noise from the premises and that emission of noise was registered or heard at the EPL monitoring points, as well as at the Coomalagah monitor, the Tarrawonga monitor, the Boggabri trigger unit, Wilberoi East, Goonbri East, by Mr Byrnes and Ms Severin at the Boggabri coal mine, and by Mr Kereopa, Ms Louis, Ms Druce and Ms Westlake at their respective private residences. For the purposes of deciding whether the prosecutor has established beyond reasonable doubt the fourth element of the s 140(1) offence, it is unnecessary to be satisfied that actual harm was caused to human health.
[126]
Addendum 31 October 2024
On 3 October 2024, the prosecutor requested that no final orders be made at the delivery of judgment in these proceedings on 4 October 2024, in order to allow it to consider its position in relation to any application pursuant to s 5AE of the Criminal Appeal Act. Accordingly, I stood each summons over until today, 31 October 2024 for the entry of final orders. I now make the following final orders.
[127]
The timing charge
In proceedings 2021/234554, the Court makes the following orders:
1. Maules Creek Coal Pty Ltd ACN 140 533 875 is guilty of an offence against section 64(1) of the Protection of the Environment Operations Act 1997 (NSW).
2. The proceedings are listed before the list judge to obtain a date for the sentence hearing and to make appropriate directions in preparation for the sentence hearing.
[128]
The stemming length charge
In proceedings 2021/234556, the Court makes the following orders:
1. Maules Creek Coal Pty Ltd ACN 140 533 875 is guilty of an offence against section 64(1) of the Protection of the Environment Operations Act 1997 (NSW).
2. The proceedings are listed before the list judge to obtain a date for the sentence hearing and to make appropriate directions in preparation for the sentence hearing.
[129]
The overloading charge
In proceedings 2021/234557, the Court makes the following orders:
1. Maules Creek Coal Pty Ltd ACN 140 533 875 is guilty of an offence against section 64(1) of the Protection of the Environment Operations Act 1997 (NSW).
2. The proceedings are listed before the list judge to obtain a date for the sentence hearing and to make appropriate directions in preparation for the sentence hearing.
[130]
The emission of noise charge
In proceedings 2021/234558, the Court makes the following orders:
1. Maules Creek Coal Pty Ltd ACN 140 533 875 is guilty of an offence against section 140(1) of the Protection of the Environment Operations Act 1997 (NSW).
2. The proceedings are listed before the list judge to obtain a date for the sentence hearing and to make appropriate directions in preparation for the sentence hearing.
[131]
Endnotes
[2023] NSWLEC 94 at [2]-[28] (Pritchard J).
(2023) 112 NSWLR 507; (2023) 258 LGERA 168; [2023] NSWCCA 275 at [118] (Leeming, Payne and Kirk JJA, Wilson and Fagan JJ).
Stiehr, ISEE Blasters' Handbook (International Society of Explosives Engineers, 18th ed, 2011).
[2023] NSWLEC 118 at [110] (Robson J).
(2008) 181 A Crim R 83 at [127] (Curtain AJA).
(1984) 152 CLR 528; [1984] HCA 5 (Brennan J).
[2020] NSWLEC 153 at [2] (Pain J).
(2003) 214 CLR 118; [2003] HCA 22 at [31] (Gleeson CJ, Gummow and Kirby JJ).
See condition 18 of the EPA Act approval set out at [31] above, and section 5.5.3.3(iv) of Dr Aimone-Martin's report dated 10 October 2022, partly extracted above at [218].
Browne v Dunn (1894) 6 R 67.
Environment Protection Authority v Truegain Pty Ltd (2013) 85 NSWLR 125; [2013] NSWCCA 204 at [53] (Leeming JA).
[2020] NSWLEC 153 at [2] (Pain J).
[2022] NSWLEC 29 at [519] (Pepper J).
Westfield Management Limited v Perpetual Trustee Company [2006] NSWCA 245 at [41] (Hodgson JA) (Tobias and Basten JJA agreeing), cited in Baulkham Hills Shire Council v Ko-veda Holiday Park Estate Ltd (2009) 167 LGERA 395; [2009] NSWCA 160 at [100] (Tobias JA) (Young JA and Bergin CJ in Eq agreeing).
Weston Aluminium Pty Limited v Environment Protection Authority & Another (No 2) (2005) 144 LGERA 7; [2005] NSWLEC 698 (Weston Aluminium) at [31] (Pain J). See also Commissioner of Police v Thayli Pty Ltd [2020] WASC 43 at [118(b)] (Smith J); Hill v O'Brien (1938) 61 CLR 96 at 113; [1938] HCA 48 (McTiernan J); R v Toohey; Ex parte Meneling Station Pty Ltd (1982) 158 CLR 327 at 344; [1982] HCA 69 (Mason J).
Weston Aluminium at [31] (Pain J).
Herzfeld and Prince, Interpretation (2nd ed, 2020, Thomson Reuters (Professional) Australia Limited) at [16.10].
(2018) 131 ACSR 215; [2018] FCA 1502 (Colvin J).
(2019) 101 NSWLR 245; (2019) 238 LGERA 147; [2019] NSWCCA 174 at [257] (Preston CJ of LEC) (Davies and Adamson JJ agreeing).
(2017) 95 NSWLR 361; (2017) 224 LGERA 301; [2017] NSWCA 191 at [45] (Basten JA) (Beazley P and Leeming JA agreeing).
[132]
Amendments
01 November 2024 - Paragraph [485] amended and entitled "Addendum 31 October 2024".
Paragraph [490] deleted "The summonses are stood over until 31 October 2024 at 4pm for the entry of final orders."
DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.
Decision last updated: 01 November 2024
Chief Executive, Office of Environment and Heritage v Orica Pty Ltd; Environment Protection Authority v Orica Pty Ltd [2015] NSWLEC 109
Commissioner of Police v Thayli Pty Ltd [2020] WASC 43
Environment Protection Authority v Bartter Enterprises Pty Ltd (No 3) [2020] NSWLEC 114
Environment Protection Authority v Buchanan (No 2) (2009) 165 LGERA 383; [2009] NSWLEC 31
Environment Protection Authority v Collex Pty Ltd (2001) 115 LGERA 337; [2001] NSWLEC 177
Environment Protection Authority v Grafil Pty Ltd; Environment Protection Authority v Mackenzie (2019) 101 NSWLR 245; (2019) 238 LGERA 147; [2019] NSWCCA 174
Environment Protection Authority v Huntsman Corporation Australia Pty Ltd [2011] NSWLEC 39
Environment Protection Authority v Maules Creek Coal Pty Ltd [2023] NSWLEC 94
Environment Protection Authority v O'Brien [2023] NSWLEC 118
Environment Protection Authority v Rethmann Australia Environmental Services Pty Ltd (2003) 131 LGERA 422; [2003] NSWLEC 351
Environment Protection Authority v Sydney Water Corporation [2020] NSWLEC 153
Environment Protection Authority v Sydney Water [2022] NSWLEC 100
Environment Protection Authority v Sydney Water Corporation [2019] NSWLEC 100
Environment Protection Authority v Truegain Pty Ltd (2013) 85 NSWLR 125; [2013] NSWCCA 204
Fox v Percy (2003) 214 CLR 118; [2003] HCA 22
Genkem Pty Ltd v Environment Protection Authority (1994) 35 NSWLR 33; (1994) 85 LGERA 197
Hill v O'Brien (1938) 61 CLR 96; [1938] HCA 48
House of Peace Pty Ltd v Bankstown City Council (2000) 48 NSWLR 498; (2000) 106 LGERA 440; [2000] NSWCA 44
Maules Creek Coal Pty Ltd v Environment Protection Authority (2023) 112 NSWLR 507; (2023) 258 LGERA 168; [2023] NSWCCA 275
McCallum v Sandercock (2011) 183 LGERA 399; [2011] NSWLEC 175
Nydam v The Queen [1977] VR 430
Perpetual Executors and Trustees Association of Australia Ltd v Federal Commissioner of Taxation (1948) 77 CLR 1; [1948] HCA 24
Plath of Department of Environment and Climate Change v Fish; Plath of Department of Environment and Climate Change v Orogen Pty Ltd (2010) 179 LGERA 386; [2010] NSWLEC 144
Polgara Pty Ltd v Vision Wise Holdings Pty Ltd (1996) NSW ConvR 55-781; [1996] ANZ ConvR 471
Prefabricated Buildings Pty Ltd v Bathurst Regional Council [2017] NSWLEC 44
R v Filiopovic; R v Gelevski (2008) 181 A Crim R 83
R v Toohey; Ex parte Meneling Station Pty Ltd (1982) 158 CLR 327; [1982] HCA 69
Sandalwood Properties Ltd v Huntley Management Ltd (2018) 131 ACSR 215; [2018] FCA 1502
Verde Terra Pty Ltd v Central Coast Council; Central Coast Council v Environment Protection Authority (No 9) [2022] NSWLEC 29
Westfield Management Limited v Perpetual Trustee Company [2006] NSWCA 245
Weston Aluminium Pty Limited v Environment Protection Authority [2021] NSWLEC 131
Weston Aluminium Pty Ltd v Environment Protection Authority and Another (No 2) (2005) 144 LGERA 7; [2005] NSWLEC 698
Texts Cited: Bronitt and McSherry, Principles of Criminal Law (4th ed, 2017, Thomson Reuters)
Herzfeld and Prince, Interpretation (2nd ed, 2020, Thomson Reuters (Professional) Australia Limited)
Macquarie Dictionary (2019, Pan Macmillan Australian Pty Ltd)
Macquarie Dictionary, online ed
Stiehr, ISEE Blasters' Handbook (18th ed, 2011, International Society of Explosives Engineers)
Category: Principal judgment
Parties: Environment Protection Authority (Prosecutor)
Maules Creek Coal Pty Ltd (Defendant)
Representation: Counsel:
C Leggat SC, A Garsia and G Marsden (Prosecutor)
T Howard SC and J Lee (Defendant)
The monitoring points 31, 32, 33 and 34 referred to in the limit conditions are named BM1, BM2, BM3 and BM4 in condition P1.4 (the EPL monitoring points).
The operating conditions (the operating conditions) in the EPL are, relevantly, as follows:
4 Operating Conditions
O1 Activities must be carried out in a competent manner
O1.1 Licensed activities must be carried out in a competent manner.
This includes:
a) the processing, handling, movement and storage of materials and substances used to carry out the activity; and
b) the treatment, storage, processing, reprocessing, transport and disposal of waste generated by the activity.
O2 Maintenance of plan and equipment
O2.1 All plant and equipment installed at the premises or used in connection with the licensed activity:
a) must be maintained in a proper and efficient condition; and
b) must be operated in a proper and efficient manner.
…
The monitoring and recording conditions include, relevantly, the following:
5 Monitoring and Recording Conditions
…
M7 Blasting
M7.1 To determine compliance with conditions L4.1 to L4.4 inclusive:
a) Airblast overpressure and ground vibration levels must be measured and electronically recorded for monitoring points 31, 32, 33 and 34 for the parameters specified in Column 1 of the table below and
b) The licensee must use the units of measure, sampling method and sample at the frequency specified opposite in the other columns.
The Dictionary in the EPL provides the following definition of activity:
activity [m]eans a scheduled or non-scheduled activity within the meaning of the Protection of the Environment Operations Act 1997
Sometime between Thursday, 13 August and Friday, 14 August 2020, Mr Gomez, Mr Williams and Mr Butler discussed the issue of fragmentation in relation to the caprock, and how it could be addressed in the final stages of design of the blast. One of the outcomes of that discussion was the engagement of Dr McKenzie on 14 August 2020 to provide advice on what the defendant could do in the time available before the scheduled blast, and with an estimated 30-50% of the drill holes already having been drilled in order to achieve better fragmentation of the caprock from the blast. Specifically, Dr McKenzie was engaged to provide advice on timing and stemming length for the blast to minimise caprock and improve fragmentation.
On Friday, 14 August 2020 at 9:40am, Mr Williams emailed Dr McKenzie, at Mr Gomez' direction, seeking his views on managing caprock fragmentation for the blast to achieve an improvement on the shot. Mr Williams said in his email that "[w]e are looking at reducing stem height from 4m to 3m and using electronic timing to help".
On Friday, 14 August 2020 at about 10:40am, Mr Williams sent an email to Mr Michael Clarke, the defendant's drill and blast superintendent, copying Mr Gomez and Mr Butler, saying "we are trying a couple new things to try and get a better result for the cap zone fragmentation in the next HRN shot".
On 14 August 2020, at about 11:30am, Mr Williams emailed Dr McKenzie a copy of the drill map and design for the blast. This was sufficient for Dr McKenzie to put the input into his predictive model, or as Dr McKenzie said in cross-examination: "... that's all I needed to do to recreate their planned blast". By this time, Dr McKenzie "was aware that the only two options for dealing with the difficulties experienced in fragmenting the capping rock, were to adjust the initiation timing and to adjust the length of stemming for the [b]last". Having received input data from Mr Williams, Dr McKenzie commenced his predictive modelling of flyrock, airblast overpressure and vibration, that the blast would generate at each of the four EPL monitoring points against a number of parameters concerning initiation timing and stemming lengths.
During the course of 14 August 2020, Mr Gomez and Dr McKenzie spoke by phone in the morning for more than 15 minutes, and again in the late afternoon for almost 26 minutes.
On 14 August 2020 at 10:02pm, Dr McKenzie emailed Mr Williams (copying Mr Gomez and Mr Butler), and said as follows in relation to his modelling of the shot:
I have spent some depressing time on the modelling of this shot. Depressing, because it tells me that the overpressure impacts may be excessive with just 2.5 metres of stemming, which is what I'd like to recommend. In fact, it says that even with 3 metres, we may be pushing our luck in combination with fast timing. Vibration is no issue. My modelling says that if we go to the fast timing, then we probably should be looking at 3.5 metres of stemming. Having said that, I would also say that modelling at distances of 8 to 9 km is a bit tricky, and can be heavily influenced by cloud cover and inversion layers which my model does not take into consideration. The inversion layers we can probably handle by not firing before mid-day, but the cloud cover may be a more difficult problem to manage. All in all, I have never had to model impacts at such extreme distances before, so I am not sure how much confidence to have in the modelling.
As I see it, there are three options:
1. We can use fast timing and more conventional stemming lengths
2. We can use 3 m stemming lengths and conventional timing
3. We can try 3 m stemming and fast timing, and use the result as a learning opportunity, since I have doubts about the ability to reliably model the impacts on the data I have available.
In cross-examination, Dr Catherine Aimone-Martin (the defendant's expert) agreed with Dr McKenzie's characterisation of the third option as a "learning opportunity" as at 10:02pm on 14 August 2020.
Between 14 and 18 August 2020, Dr McKenzie undertook modelling to minimise overpressure and vibration resulting from the blast at the monitoring locations in the north-east of the mine. In order to do so, he was supplied with the coordinates of the EPL monitoring points, BM1, BM2, BM3 and BM4.
On the morning of Monday, 17 August 2020, Mr Butler took over the role of finalising the charge design for the blast from Mr Williams who was then on leave. Mr Butler had been involved in the design of the blast under the supervision of Mr Williams in the previous weeks and proceeded to work under the supervision of Mr Gomez. Mr Gomez' evidence was that "[Mr Butler] and me discussed everything".
On 17 August 2020 at 8:21am, Mr Butler emailed Dr McKenzie informing him that Mr Williams was on leave and asking for clarification about how to import the timing data provided by Dr McKenzie for use in the defendant's software. Later that morning at 10:12am, Dr McKenzie replied to Mr Butler's email (copying Mr Gomez) with the timing details, and advised Mr Butler as follows:
[i]t's all very fast, deliberately. But happy to discuss any concerns you may have.
At about 11:00am on 17 August 2020, Mr Gomez and Dr McKenzie had a phone call of about 16 minutes duration during which, according to Mr Gomez, they discussed adding "a layer of conservatism to the airblast overpressure by directing the modelling to achieve the EPL 95 percentile limits (114 or 115 dBL)".
At 11:34am on 17 August 2020, Dr McKenzie emailed Mr Butler regarding the appropriate clearance distance for the blast, taking into account both fast timing and reduced stemming. Dr McKenzie suggested a 700m personnel clearance distance, and noted that "this blast is a departure from standard blasting practice at Maules Creek".
It was not in dispute that Dr McKenzie was not asked to consider the potential impact of the blast on personnel at the adjacent Boggabri coal mine located less than 3km to the south of the mine, with its crib hut and go line located approximately 2.9km from the proposed blast location. The location of personnel at the Boggabri coal mine (Ms Rebecca Severin and Mr Jonathon Byrnes), as well as residents at neighbouring properties, namely Ms Roselyn Druce, Ms Christine Westlake, Mr Kereopa and Ms Lynette Louis at the time of the blast, is marked on the aerial photograph extracted from a report of the prosecutor's expert, Dr Alan Cameron, below:
In his record of interview dated 24 May 2021, Dr McKenzie explained that he did not do any modelling to the south of the mine because it was outside his scope of work, that he was approached to provide advice about impacts, and that he was given information about the EPL monitoring points. Dr McKenzie agreed that he was not given any information in relation to any other sensitive areas around the mine.
On 18 August 2020, there were seven telephone conversations between Mr Gomez and Dr McKenzie with a total duration of about 55 minutes.
On 18 August 2020 at 10:47am, Mr Butler emailed Dr McKenzie the timing contours he had devised for the blast. Dr McKenzie replied at 10:57am, and noted "that looks fine to me … I have no issues with it". Later, on 18 August 2020 at 2:39pm, Mr Gomez emailed Dr McKenzie vibration and overpressure readings from the previous blast at the mine.
In preparing the updated modelling, Dr McKenzie used data from the previous blast on 7 August 2020 to calibrate the model and make predictions for the blast. Using the previous blast's data, Dr McKenzie highlighted that the airblast overpressure level predictions were about 2 decibels (Lin Peak) (dBL) "higher than what was recorded at the [four EPL] monitors", and made the following comments in an email sent to Mr Gomez on 18 August 2020 at 4:43pm:
[t]he model takes into account the fast timing presented in the attached pdf file, but has not accounted for the delayed section of the blast near to the final highwall. That should only tend to reduce the levels, so I consider the estimates to be conservative from that point of view
In relation to the scenario of fast timing and 3.0m stemming, Dr McKenzie's model predicted airblast overpressure levels at each of the four EPL monitoring points as shown in the second column of the table below:
EPL Monitoring Points Airblast overpressure predicted by the McKenzie Model (dBL) Actual overpressure of blast (dBL)
BM1 112.7 110.8
BM2 111.5 115.1
BM3 114.1 116.5
BM4 114.8 107.6
Based on Hanwha's records, the MMUs recorded delivered to the mine were:
1. 5,871kg of XLOAD 60-100 of explosive product for shot A; and
2. 877,773kg of XLOAD 60-100 explosive product and 15,483kg of XLOAD 70-110 explosive product, totalling 893,256kg of explosive product for shot B.
According to the Maules Creek Coal Jobpack Blast Checklist for the blast on 20 August 2020, there were 1,197 "pegs"; that is, 62 more blast holes than the 1,135 blast holes recorded on the load sheets. Further, the checklist recorded the total used explosives as 893,246kg, and the "Blast Comments" as "2 Initiation Points, Very quick timing. Good Frag".
I find established beyond reasonable doubt that the total amount of explosives loaded in the blast on 20 August 2020 was 896,256kg as stated in Ms Bulkeley's email to Mr Lund on 31 August 2021.
Clause 3.3.1 provided in relation to unfavourable weather conditions such as wind speed and wind direction:
The following outlines unfavourable/adverse weather conditions and the site response to those conditions.
When the site automatic weather station (AWS) records wind direction from the north (270° through to 90°) and wind speed greater than 8m/s over successive readings, blasting will not occur unless required for safety reasons. Blasting will not occur when the AWS records wind direction from the south (90° through to 270°) and wind speed is greater than 6m/s over successive readings …
Clause 3.3.5 provided in relation to air vibrations (overpressure) management:
3.3.5 Air Vibrations (Overpressure) Management
Noise (the audible part of the air vibration spectrum) and airblast (the remaining sub-audible part of the air vibration spectrum) generation can be controlled by ensuring that all, or nearly all, of the explosion energy is consumed in fragmenting and displacing the overburden by the time the gases vent (via the broken burden rock and/or ejected stemming material) into the atmosphere. Blast events are designed to meet the relevant overpressure and ground vibration criteria.
and that (emphasis added):
This objective will be met by ensuring that:
• Where practicable, the blast face is orientated away from or at an oblique angle to nearby residences;
• Blast hole spacing is implemented in accordance with blast design;
• The burden distance and stemming length are carefully selected and then implemented precisely;
• Appropriate materials (e.g. 20 mm aggregates) are used for stemming;
• Charges detonate in the correct sequence and with inter-row delays that provide good progressive release of burden; [the fifth dot point in cl 3.3.5 of the BLMP]
• The maximum weight of explosive detonated in a given delay period (the Maximum Instantaneous Charge - MIC) is limited to conservative and proven levels; [the sixth dot point in cl 3.3.5 of the BLMP]
• Conducting blasting during suitable meteorological conditions as described in Sections 3.2 and 3.3 [together, the seven dot points in cl 3.3.5 of the BLMP].
Clause 4.1 provided in relation to monitoring of blast vibration and overpressure:
Blasting generates noise (i.e overpressure or airblast) and vibration, which can be detectable at residential receptor locations. …
…
In accordance with Schedule 3, Condition 18 of [the EPA Act approval], blasting must not exceed the relevant criteria for airblast overpressure (dB (Lin Peak) and Ground Vibration (mm/s) at any residence on privately owned land. The monitoring locations above are representative of residences on privately owned land and as such, will be used to assess compliance with blasting criteria …
In Appendix J to the Australian Standard, titled "Ground Vibration and Airblast Overpressure (Informative)" (Appendix J to the Australian Standard), section J1 provides relevantly:
The contents of this Appendix are designed to be informative and are not intended to over-ride existing statutory requirements, particularly with respect to human comfort limits set by various authorities.
…
Blasts should be designed according to the prevailing regulatory controls from both a human comfort and damage perspective.
…
Section J2.2 provides relevantly in relation to airblast:
Airblast is the pressure wave (sound) produced by the blast and transmitted through the air. Unlike ground vibration there is only one airblast phase but it too is a complex wave-train consisting of various peaks and with a range of frequencies. The sources of airblast include a usually small air pressure pulse generated by the ground vibration, a direct air pressure pulse generated by the rock movement during blasting and an air pressure pulse caused by direct venting of gases from the region of the blast. It is important to recognise that airblast may be reflected by layers within the atmosphere and that the airblast may be refocused at distances remote from the blast.
…
Section J4.5 provides relevantly in relation to recommended ground vibration limits:
…
The maximum levels for ground vibration for human comfort, which some authorities have chosen, are provided in Table J4.5(A). Recommended limits for ground vibration for control of damages to structures are provided in Table J4.5(B).
…
Table J4.5(A) provides in relation to ground vibration limits for human comfort chosen by some regulatory authorities:
GROUND VIBRATION LIMTIS FOR HUMAN COMFORT CHOSEN BY SOME REGULATORY AUTHORITIES (see Note to Table J4.5(B))
Category Type of blasting operations Peak component particle velocity (mm/s)
Sensitive site* Operations lasting longer than 12 months or more than 20 blasts 5 mm/s for 95% blasts per year 10 mm/s maximum unless agreement is reached with the occupier that a higher limit may apply
Sensitive site* Operations lasting for less than 12 months or less than 20 blasts 10 mm/s maximum unless agreement is reached with occupier that a higher limit may apply
Occupied non-sensitive sites, such as factories and commercial premises … …
The Dictionary to the POEO Act provided (at all relevant times) relevantly:
activity means an industrial, agricultural or commercial activity or an activity of any other nature whatever (including the keeping of a substance or an animal).
…
noise includes sound and vibration.
…
non-scheduled activity means an activity that is not a scheduled activity and is not scheduled development work.
occupier of premises means the person who has management or control of the premises.
…
scheduled activity means an activity listed in Schedule 1.
Parts 1 and 2 of Schedule 1 titled "Scheduled activities" list the activities that are scheduled activities for the purposes of the POEO Act. Part 1 (at all relevant times) provided:
Part 1 Premises-based activities
…
10 Coal works
…
16 Crushing, grinding or separating
…
28 Mining for coal
…
The defendant relied on provisions of the Work Health and Safety Act 2011 (NSW) (Work Health and Safety Act), in particular s 18 which provided as follows:
18 What is "reasonably practicable" in ensuring health and safety
In this Act, reasonably practicable, in relation to a duty to ensure health and safety, means that which is, or was at a particular time, reasonably able to be done in relation to ensuring health and safety, taking into account and weighing up all relevant matters including -
(a) the likelihood of the hazard or the risk concerned occurring, and
(b) the degree of harm that might result from the hazard or the risk, and
(c) what the person concerned knows, or ought reasonably to know, about -
(i) the hazard or the risk, and
(ii) ways of eliminating or minimising the risk, and
(d) the availability and suitability of ways to eliminate or minimise the risk, and
(e) after assessing the extent of the risk and the available ways of eliminating or minimising the risk, the cost associated with available ways of eliminating or minimising the risk, including whether the cost is grossly disproportionate to the risk.
and s 19(1) which provided:
19 Primary duty of care
(1) A person conducting a business or undertaking must ensure, so far as is reasonably practicable, the health and safety of -
(a) workers engaged, or caused to be engaged by the person, and
(b) workers whose activities in carrying out work are influenced or directed by the person,
while the workers are at work in the business or undertaking.
In relation to the Court's general discretion to limit the use of evidence, s 136 of Evidence Act provides:
136 General discretion to limit use of evidence
The court may limit the use to be made of evidence if there is a danger that a particular use of the evidence might -
(a) be unfairly prejudicial to a party, or
(b) be misleading or confusing.
In relation to what he was asked to model for the blast scheduled for 19 August 2020, Dr McKenzie said in cross-examination:
A. … they needed help with - to improve the fragmentation because of a concern about operator safety and what could I do to improve the fragmentation, what could be done with the design at this rather late stage and was then, during that discussion, that it became clear that the blast had already - the blast holes had already been drilled. So there's a pattern lying on the ground now, so we would have talked about what options are available at this stage.
In relation to the design aspects that could be controlled to change the fragmentation outcome for the blast, Dr McKenzie said in cross-examination:
A. … we looked at different stemming lengths and we looked at different timing, because we identified early on they were our only two options at the late stage of what we could change. So, that was just one of the combinations that I studied that I shared the results with them and there were many others that I looked at as well.
In relation to the modelling exercise he undertook in the period prior to the blast on 20 August 2020, Dr McKenzie said in cross-examination:
A. … The mine did not give me scenarios to model. The mine is asking for assistance and relying on my experience and capabilities. So you may have inferred from the emails that I originally wanted to consider 2 and a half metres of stemming, which is a very short stemming that diameter hole. So I would have - my modelling then means that I have to approach the blast hole pattern for which I have blast hold co-ordinates.
So I have in front of me on my screen a visualisation of what that pattern looks like on the ground and now I can be the loading truck and I can come along and I can load so much explosive into all of those holes and adjust the stemming length and then I go and do the modelling, which takes into account the individual loading characteristics of every single hole. So it does the analysis hole by hole and I then I look at, first of all, what is going to be the flyrock risk. Is it feasible to do that and to request a larger evacuation radius and then I go and look at what will be the effect of that pattern and that timing on the vibration and the overpressure levels and, as I said, the models that I use consider each hole on its own merits and its - each hole's contribution to the final outcome.
In relation to his email sent at 10:02pm on Friday, 14 August 2020 to Mr Williams, copied to Mr Gomez, in which he said "I have spent some depressing time on the modelling of this shot", Dr McKenzie gave the following evidence in re-examination:
A. … when I undertook my modelling I was hoping that I would be able to show the mine that they could use the fastest possible timing, minimal amount of stemming and, therefore, the greatest possibility of getting acceptable or good results and minimising oversight. So after such a lengthy period of modelling, if I can't come up with the answer I wanted, then I'm a little disappointed, depressed.
In relation to a biodiversity corridor, Dr McKenzie said as follows in examination in chief:
Q 206. … Ryan [Gomez] never mentioned to you anything about a biodiversity corridor?
A. Sorry, yes he did … it's not written anywhere but he did mention that in the telephone discussion … He never sent me a file or any information which identified exactly where that was but you will note in an email from Lee Butler that he said that in implementing the recommended timing solution he included an additional very large delay for the last five rows of the shot. And that was specifically to address any material being thrown back onto the biodiversity zone …
In relation to the timing charge and the concepts of burden relief and burden release, Dr McKenzie said in cross-examination:
A. Burden relief, … if we refer back to the blast of August 20, there were almost 1,200 blast holes. Now when you initiate 1,200 blast holes, they go basically one by one … there's this delay between them. Now typically, if we look at the conventional methodology associated with timing of a large blast, you could - you arrange it so that the rock, when it - when the explosive detonates, it moves the rock forward like a wave, and then there's a bit of a brief pause and then the next row of holes moves forward. And that whole concept of burden relief relates to how long you have between those waves of rock moving. And that really is only useful to us when we want to think about the ease with which the material will be excavated, okay?
… there is no model in the world that says that you need to have a particular burden relief in order to control overpressure or vibration or fragmentation. It's all about onsite experience and what gives the loosest - a muck pile which is loose, nice and loose for an excavator to dig.
…
Q. … What about the concept of burden release …
A. … it's not terribly different from burden relief.
Q. …Then what can you tell her Honour, if anything, about the concept of progressive release of burden?
A. Well we always have progressive relief of burden. Unless you were to fire all of those holes instantaneously, then, then you have a hole here and a hole there and hole behind it, and it's recurring. And that process is providing a progressive movement of the detonation and of the fragmentation progress through the volume of the rock. …
In relation to the timing charge, in particular in relation to the concept of electronic timing, Dr McKenzie gave the following evidence in cross-examination:
A. … electronic timing is, is a relatively new concept … it was designed to give precision. So, if I step back now and look at its, its alternative, the non electric initiation, this is an odd system really whereby we lower a, a detonator with, with what's called a booster, which is the high explosives. …
In relation to the stemming length charge and the issue of whether the defendant carried out licensed activities in a competent manner, Dr McKenzie gave the following evidence in cross-examination (emphasis added):
Q. … The proposition is put this way:
"The defendant did not carry out licensed activities in a competent manner because it designed the blast with a stemming length for the blast holes of 3.0 metres, which deviated from the defendant's approved design standard ST_HRN_229_OB_D_1."
Are you in a position to respond to that proposition to her Honour?
A. Well, I don't see anything in there that would support any, any claim of a lack of competence. Yes, it has deviated from what would be a normal standard, but the whole blast was being done differently. If the blast had been designed for 5 metres of stemming, but was implement[ed] with 3 that would be incompetent. As far as I can see, it was designed for a stemming length of 3 and that's what was implemented following a process of assessment and best possible means of evaluating outcomes. So I can't see how what they did could be called incompetent.
In relation to the overloading charge, Dr McKenzie gave the following evidence in cross-examination:
Q. Let's take a particular hole in this drilling pattern. If the design weight of explosive plus 10% did not bring the explosive column up to the bottom of the stemming stratum, that would mean, wouldn't it, by your logic, that the loader would face a choice of either exceeding the 10% limit or not loading up to the design stemming height?
A. That's correct.
Q. Faced with that choice, then I suggest to you that it's certainly not a failure to carry out that activity in a competent manner to take the explosive up to the designed stemming height?
A. … there are various reasons it could be not coming out and if you get extra explosives in the hole, it's, it's a safety issue. So, you're adding extra explosives and you then have the potential you don't know where the explosive is going, you have the potential of causing more fly rock or noise or things like that.
Q. Well, the issue of fly rock was quite carefully modelled, wasn't it, by Dr McKenzie before the subject blast, you accept that, don't you?
A. Assuming ideal conditions, yes. What we are getting is, is non-ideal conditions so if there happened to be a [cavern] or something there that was getting full of explosives, then that is something that, that has potential for a safety issue.
In relation to the overloading charge, Dr McKenzie also gave the following evidence in re-examination:
Q. My learned friend … gave a hypothetical example, which started with the words, "Let's take a particular hole", and then referred to the loading of that particular hole. In the course of your answer you said, "It is a safety issue" or "that gives rise to a safety issue", the hypothetical that Mr Howard was identifying. What do you mean by that?
A. I believe when we were talking about - was that when the discussion was about the hole not coming up to the correct level and explosives - the quantity of explosives had been loaded into it, and then if too much explosive goes into the hole, or extra goes into the hole, then the possibility of the surface breaking up because there is extra explosive, excessively breaking up, and that adds to the - that's a safety issue in terms of the flyrock and air blasting.
Mr Gomez testified that at the time of Dr McKenzie's engagement in August 2020, the drilling of the pattern for the blast was partially completed:
A. …we found out that there was the blast adjacent to the current blast that had some caprock or, or large boulders in layman's terms. So, the current blast had already been partially drilled, from memory. … the only things we could control after the blast had already been partially drilled was the stemming and the timing to change the outcome of the blast.
…
Q. … Let's assume that the [superintendent's] meeting was Thursday, 13 August 2020. What's your best recollection of whether any of the holes for the blast had been drilled by the time of that meeting?
A. Yeah, my recollection is that the blast was half drilled or definitely had holes in it. It was already partially drilled.
…
A. Yeah, that's correct, yeah, 50% of the number of holes. That's me just taking a guess. I don't exactly know how many.
In relation to the decision to use a 3.0m stemming length and fast timing, Mr Gomez testified:
A. … So, after extensive modelling, yeah, after a lot of modelling and looking at the results of that model, we landed or I made the decision of landing with a stemming length of 3 metres, yes.
…
Q. The best recollection of events in August 2020, does that include that it was your decision in relation to timing as well as stemming?
A. That's accurate. Yes.
Mr Gomez' evidence in relation to when he decided to use 3.0m stemming and fast timing was as follows:
Q. To the best of your recollection, approximately when on what day did you make the decision about the stemming length?
A. The stemming length decision could've been earlier than - well, much earlier than the firing date. Maybe two days earlier, but the actual timing decision would've been made, looking at this email, based on the results from Tuesday 18 August, so the stemming would've been before that. I don't know exactly when, but the decision of stemming would've been before that.
In relation to his experience of the blast, Mr Gomez testified (emphasis added):
A. … after the blast, because of the vibration, I thought we had exceeded our noise limit. So I was uncomfortable after that. The thought at the back of my mind was had we exceeded all the extensive modelling that we'd done, so uncomfortable after.
Q. Why was it that you felt uncomfortable after experiencing the blast?
A. It was the vibration was more than I would have anticipated. This is the perception of it. Results of the vibration were as per the model, as close to what we modelled, but just after the blast and feeling the impact, like I said, I most certainly thought we had exceeded the modelling that we did.
Q. Did you form a view as to whether the blast was in or out of the ordinary?
A. Look, the blast was most certainly not an ordinary blast. When I say not an ordinary blast, in my view it was - we have a set of standards. It deviated from that standard. So if something deviates from the standard, the way I'd like to put it, it's not your every day blast.
In relation to overloading, Mr Gomez' evidence was that, as at August 2020, his view was:
A. … what overloading meant from a holistic blast point of view was that if the total kilos of the whole blast exceeded the design … by, exceeded the blast by 10 per cent, then you could say the shot's overloaded. So if there was 1,000 kilos in the whole blast and you had over 11 hundred for the whole blast, my view was you could say the blast was overloaded.
In relation to his recollection of the blast on 20 August 2020, Mr Welch testified:
Q. Was there anything about the shot on 20 August 2020 that stands out in your recollection?
A. The most impressive shot I've ever seen.
…
Q. What do you mean by that?
A. It was very quick. It all went off - like, usually, you watch a shot and you can see it peel away in little segmentations. This basically went bang. I think it was .6 of a second, something like that.
Q. Were there any other features of the shot that you fired on 20 August 2020 which caused you to form the view that it was the most impressive shot you've ever seen?
A. No, just, it just all went off together. It was visually spectacular.
Q. When you say it was visually spectacular, what do you mean by that?
A. If you have a look at the shot that we fired prior to that, you can see that it's firing nice and sequentially. You can see it peeling away and you can see it timing across the shot in an orderly fashion and then if you have a look at this one, you can see it just goes, "bang".
During Mr Welch's examination in chief, over the defendant's objection, the prosecutor played two videos titled "Video of the Shot/Blast" and "Video of the Shot Taken by Drone" which both record the blast on 20 August 2020. I allowed the videos to be played for the purpose of confined questions being directed to Mr Welch about them.
The following images are screenshots from the videos played to the Court:
After the two videos were played, Mr Welch confirmed that his voice could be heard in the first video.
In the glossary section of his report of 4 November 2021, Dr Cameron defined powder factor as "a ratio between the amount of explosives loaded and the amount of rock broken". He defined airblast (overpressure) as "[a]n airborne shock wave (sound) resulting from the detonation of explosives"; and maximum instantaneous charge (MIC) as "the maximum amount of explosive that is initiated within an 8ms time window".
In his supplementary report dated 24 May 2022 (to which there were also numerous objections and which were also the subject of rulings), Dr Cameron responded to a correction notice from the defendant.
On 31 January 2023, the Court admitted Dr Cameron's supplementary opinion dated 9 December 2022 subject to a decision by the defendant to call Dr Aimone-Martin and to rely on her report of 10 October 2022. Dr Aimone-Martin was subsequently called by the defendant, and I therefore admitted the supplementary opinion of Dr Cameron dated 9 December 2022.
In his supplementary opinion of 9 December 2022 (to which there were numerous objections and which were also the subject of rulings) in response to Dr Aimone-Martin's report of 10 October 2022, Dr Cameron opined (emphasis added):
2.3 "Dr Cameron cannot possibly verify that "large volumes of high-pressure gases" were released into the atmosphere without sampling the gases immediately after blast detonation …
24. I disagree with this statement because the large volumes of high-pressure gases are visible in videos of the blast …This is also supported by the ISEE Blasters' Handbook …
25. [which at p 184] describes the energy from detonation of explosives as "Upon detonation all explosives react chemically to produce shock, heat (exothermic reaction and mostly gaseous reaction products".
26. From Page 145 of the ISEE Blasters' Handbook "However, if the blast is designed with too little burden or stemming and/or too high of a powder factor, premature movement of the rock can release explosive energy in the form of jetting gases …
29. It is obvious from the videos of [the blast] … that a large amount of high pressure gas (steam), rock and dust was ejected from the surface and side of the blast (see Figures 4a, 4b, 5 & 6). This was done by the high-pressure gasses generated by the detonation of the explosives …
Figure 4a. Image from video of [the blast] (DJI_0638.MP4 @ 00:00:12.06). Plumes of steam ejecting from the blast can be seen as well as rock and dust being thrown from the upper surface and side. (I removed the haze and sharpened the image using Photoshop Elements to improve clarity)
Figure 4b. Image from video of [the blast] (DJI_0638.MP4 @ 00:00:13:03). Plumes of steam ejecting from the blast can be seen as well as rock and dust being thrown from the upper surface and side. (I removed the haze and sharpened the image using Photoshop Elements to improve clarity)
Figure 5. Image from video of [the blast] (20200820_102241.MP4 @ 00:11:12). Plumes of steam ejecting from the blast can be seen as well as rock and dust being thrown from the upper surface and side. (I removed the haze and sharpened the image using Photoshop Elements to improve clarity)
Figure 6. Image from video of [the blast] (DJI_0638.MP4 @ 03:57:09). Plume of dust drifting from the blast site. (I removed the haze and sharpened the image using Photoshop Elements to improve clarity)
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3.1 "Six of the seven objectives outlined in section 3.3.5 of the [BLMP] were met by [the defendant]"
41. This statement is not correct. Only five of the seven design criteria were followed …
3.3 "[The defendant] indeed utilized an appropriate fast delay timing designed to achieve good progressive vertical release required for the lifting blast." (Dr Aimone-Martin Report Section 5.1.2 ...)
43. I do not agree … because with the fast timing the adjacent and dependent holes do not have enough time to move their rock before the subsequent holes are initiated. This is confirmed by the ISEE Blaster's Handbook 18th edition … The fast timing used for [the blast] resulted in less than 10ms of burden release time therefore progressive vertical release was not achieved.
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3.6 "Loaded explosives charge weights are not a design parameter" (Dr Aimone-Martin Report Section 5.4.2 …)
48. I disagree with this statement because the explosive charge weight for each hole in the blast is calculated based on the measured hole depth, explosive parameters, stemming length and hole diameter then entered into Charge Sheets by the drill and blast engineers …This is confirmed by Section 3.5 of the [loading and stemming blast holes procedure]" …
3.7 "The + 10% variance alluded to herein does not apply to explosives weights loaded into the holes …" (Dr Aimone-Martin Report Section 5.4.2 …)
49. I disagree with this statement because it is clear in the [loading and stemming blast holes procedure] that "Load sheets specify the design kg and the maximum kg) … The maximum kg shown … is +10% of the Design Kg …
In relation to the emission of noise charge and in response to section 5.5.2 of Dr Aimone-Martin's report of 10 October 2022, Dr Cameron opined as follows (emphasis added):
3.12 "MCC did not deal with explosive materials in an improper and inefficient manner. The dealing of explosive materials and the manner in which the blast was designed with a 3m stem length and fast delay timing for the intended purpose of improving rock fragmentation was appropriate and achieved the objective of improved fragmentation without exceeding air overpressure and vibration limits at the monitoring locations …"
55. I disagree with these statements because:
55.1 The design did not meet an over-riding provision of [the Australian Standard] Section 4.1 … because no consideration was given to impact on personnel at Boggabri Mine … personnel were less than 3,000m from the blast site …
55.2 The design resulted in high levels of air blast overpressure due to the sudden movement of the surface of the blast and the release of high-pressure gases …
55.3 The early release of high-pressure gases is a waste of explosive energy …
3.13 "Post-blast analysis of the fragmentation and digging rates for this blast indicated improvements as expected. Therefore the explosive energy was efficiently designed and utilized to fragment the rock as modelled by Mr. McKenzie."
56. I disagree … because a significant amount of explosive energy was released … and therefore wasted ….
3.14 "It is standard practice in the mining industry to make such blast design modifications to improve safety and efficiency"
57. I disagree … because … when blasting in a sensitive environment such as Maules (for example private residences and commercial operations nearby) a change is made only to one design parameter at a time and limited trial is made …
In cross-examination, Dr Cameron agreed with the proposition that one way of dealing with the work health and safety issue that can arise when rocks that are too large to go into the back of a truck in a muck pile is increasing the fragmentation. In relation to the previous blast, work health and safety issues, and the objective of the design, Dr Cameron testified as to his belief that there had been coarse fragmentation in the "upper areas" of the previous blast, and accepted that sometimes there is a work health and safety problem, but that there are "operational ways" that can be minimised. He also said:
Q. Dr Cameron, you agreed with the propositions I put to you that the [defendant], faced with a known issue of inadequate fragmentation, had engaged an eminent consultant, that is, Dr Cameron McKenzie, for the dual objectives of attempting to deal firstly with the fragmentation problem. … You accept … that the objective of the design changes recommended by Dr McKenzie included the objective of improving the fragmentation of the capping rock and the Herndale seam?
...
Q. Just dealing with Cameron McKenzie's objectives, did he achieve them?
A. … based on what he was given and asked to do, he achieved them.
And further, in relation to the achievement of the objective of dealing with work health and safety and the issue of inadequate fragmentation which was raised at the superintendent's meeting on Thursday, 13 August 2020, Dr Cameron agreed that the objective was achieved, and that it would have been remiss not to deal with it. Dr Cameron agreed that these circumstances were "indications" of competence.
In relation to the timing charge, Dr Cameron agreed that the activity of blast design and the activity of carrying out the blast are separate activities.
In relation to the stemming length charge, Dr Cameron maintained that the reduction of the stemming height to 3.0m by itself posed a difficulty, and that the design should not have moved from the drill and blast design standard fixed pattern stemming of 3.5m (emphasis added):
Q. But that's just a standard, isn't it?
A. The previous design that had caused the fragmentation was at 4 metre stemming, right, which was more than even the limit of the design standard. So, to move that then to 3 metres stemming, in my opinion, was a significant change, and was a concern.
Q. Why would you compare the 3-metre stemming to the 4-metre stemming that had been used in the previous blast rather than the 3.5 that's in the standard?
A. Because the previous blast was the one that produced the courser fragmentation and that it was a concern, and so the next step generally would have been to move to a 3.5 metre stemming.
…
Q. But there's nothing wrong per se with having a stemming height that's not the same as the standard, is there?
A. The standards were developed based on Maules Creek experience and had been established for their safe operation. That's what they were using, yes.
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Q. A moment ago you gave evidence that the 4-metre stemming in the previous blast was not incompetent. Do you agree that you gave that evidence?
A. Yes.
Q. That deviated from the stemming height by half a metre, that is, the standard stemming height by half a metre, didn't it?
A. Yes.
Q. So did the subject blast deviate by exactly the same amount? Do you agree?
A. Yes. It got less by that amount, but if you look at normal stemming heights, a range as a percentage or as a - in relation to the whole diameter, and to go to that short a stemming has potential to cause issues. Any increases are a potential to cause issues.
And further in relation to the stemming length charge (emphasis added):
Q. Well, it follows from the evidence you've already given, doesn't it, where you said that a 4-metre stemming would be not incompetent, that you can deviate from the standard without being incompetent. That follows, doesn't it?
A. In reducing the stemming to that level, I would suggest, in my opinion, it's not competent.
In relation to the overloading charge, Dr Cameron gave the following evidence in relation to the loading and stemming blast holes procedure:
Q. You agree that the procedure does not state, make any statement that a plus or minus 10% tolerance applies to individual holes?
A. That procedure does not say 10 - plus minus 10% no.
Q. It simply extracts an example of a load sheet, doesn't it?
A. Yes.
Q. Coming back to then your report at … section 2.3 the proposition you put there in the first sentence doesn't derive from the loading and stemming blast holes procedure, does it?
…
Q. What you say at paragraph 2.3, that is the proposition that the maximum is 10% more than the designed amount does not derive from the Whitehaven Coal loading and stemming blast holes procedure, does it?
A. No it's just indicated on that table but no.
And further in relation to the overloading charge, it was put to Dr Cameron that he had not cited any evidence which supported the proposition that there is an overloading of a hole if it is more than 10% above the design weight. Dr Cameron said that was based on his experience. Dr Cameron did not accept that only referring to the blast holes with more explosive product than designed and not referring to the holes with less explosive product than designed represented a distorted picture. Dr Cameron accepted that there is no design powder factor for individual holes nominated in the loading and stemming blast holes procedure, and agreed that in his experience, there is never a design powder factor for individual holes in mine blasting.
Dr Cameron accepted that if a person on the ground involved in loading the subject charge loaded a hole to the point where it came to the bottom of the 3.0m stemming stratum and that the explosive product subsequently settled, then the person, if they wished to implement Dr McKenzie's recommendation, would top up the explosive so that it came back up to the 3.0m point. He accepted that that would have the consequence that there would be a greater weight in the hole than what was originally put in it. He also accepted, assuming that what was originally put in the hole, as designed, and came up to the 3.0m stemming height, but then settled, and then more product was placed in it to bring it back up to the 3.0m stemming height, that would have the consequence that there was a greater weight of explosive in the hole than the design. Dr Cameron also accepted that the defendant had experienced some difficulty with the particular explosive products in settling, and that this was one possible reason why some of the holes had more explosive weight in them than the design.
In relation to the emission of noise charge, Dr Cameron agreed that the objectives of the improvement of fragmentation and compliance with the limits for noise at the monitoring locations were both achieved. He also accepted that he did not have or profess to have any medical qualifications, or qualifications as an acoustic engineer. When it was put to him that the topic of noise or airblast pressure levels at which it might be expected that humans might be discomforted was a matter outside his expertise, he responded: "[t]hat is something that's documented in the blasting literature". When pressed, he agreed that he has no expertise in relation to assessment of the level at which it might be expected that humans would be discomforted by noise.
In relation to the EPL, Dr Cameron (who did not have his briefing material with him when he gave evidence) was unsure whether there was a regulatory instrument in the form of an environment protection licence separate to the approval.
Dr Aimone-Martin's comments in relation to the stemming length charge, referred to by her as charge 3, were as follows (footnotes omitted, emphasis added):
4.3 Charge 3: MCC carried out blast HRN_08_39_OB in a competent manner by carefully considering a reduction in stem length from 3.5m to 3.0m to improve blast performance in terms of reduce blasted rock fragmentation sizes and dig rates based on unfavorable site overburden (caprock) geology. The design change was consistent with the Blast Management Plan and properly documented using the required blast design checklist WHCCHK-OC-Drill and Blast Design and approved by MCC management personnel in August 2020, prior to conducting blast HRN_08_39_OB. … In my opinion, the selection of 3m stemming by MCC personnel was appropriate to address cap rock problems and demonstrated an efficient and competent use of blasting materials.
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5.3.1 Did MCC fail to carry out the subject blast in a competent manner by reason of the circumstance that it designed the blast with a stemming length for the blast holes of 3.0m, which deviated from MCC's Approved Design Standard?
Response
I do not agree that the 3m stem length caused blast HRN_08_39_OB to be carried out in an incompetent manner in that it deviated from the Approved Design Standard. In fact, the change in stem length from 3.5m to 3m was properly planned and documented using the required document form indicating a change in design parameters. Therefore, the stem length change was properly documented in advance of blast HRN_08_39_OB planning and included modelling of fragmentation, ground vibrations and air overpressures by blast consultant Cameron McKenzie and MCC personnel. In my opinion, MCC carried out the blast in a competent manner.
Mr. Williams … prepared the appropriate paperwork to change the stem height noted in the Fixed Pattern as 3.5m to 3m on the required Drill & Blast Design Checklist form … This form was initiated and signed on 4 August 2020 in advance of final planning of the subject blast. Thus, Mr. Williams performed his due … diligence and adhered to MCC Management of Change policy by correctly modifying the Approved Standard Design. In my opinion, the notion that the stem length change from 3.5 to 3m for blast HRN_08_39_OB represented a deviation from the Approved Design Standard in unfounded because the 3m stem was indeed approved with appropriate paperwork. This action clearly represented competency in carrying out required paper work and planning for the blast.
The change from 3.5 to 3m stemming was appropriate in that it was selected to improve rock fragmentation and the productivity and safety of equipment and mine workers in the removal of blasted rock. The reduction of stemming length was necessary to fracture the hard caprock that persisted in this area of blast HRN_08_39_OB and represents normal blast design modifications to improve fragmentation.
… the manner in which MCC personnel and blast consultant Mr. Cameron McKenzie collaborated on the stemming length design change demonstrated a high level of competency to achieve productivity and worker safety in rock blasting when confronted with a hard caprock. I agree with the stem length change to 3m as it was appropriate given the objective it was trying to achieve.
Dr Aimone-Martin's comments in relation to the overloading charge, referred to by her as charge 4, were as follows (footnotes omitted, emphasis added):
4.4 Charge 4: MCC carried out blast HRN_08_39_OB in a competent manner by maintaining the drill pattern and loading parameters outlined in the approved Drill and Blast Design Standard Fixed Pattern well within the 10% variance allowance for each parameter. … The concept of overloaded blast holes, referring to the charge weight loaded into the blast holes, is not a design parameter subject to the 10% allowance. The EPA implies that explosive overloading occurs when the loading of charge weight exceeds that which was planned. In reality, it is only the variations in design parameters and most importantly, powder factor, that must remain within the 10% variance and powder factor indeed remained well below the 10% allowance. The 10% variance does not apply to loaded charge weights. … It is my opinion, variations in explosives charge weights loaded in drilled blast holes should be measured in the aggregate over all blast holes. …
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5.4.1 Did MCC fail to carry out the subject blast in a competent manner by reason of the alleged circumstance that MCC overloaded approximately 19% of blast holes for the blast with more than 10% of the amount of explosives prescribed in the design for the blast - this being allegedly in contravention of MCC' s procedure for loading and stemming blast holes (Document No. WHC-PRO-OC-Loading and Stemming of Blast Holes)?
5.4.2 Response
MCC did not fail to carry out the subject blast in a competent manner by reason of overloading 19% of the blast holes by 10% of the planned explosives charge weight. I find that the negative connotation of the phrase "overloading explosives in blast holes" to be a misrepresentation of facts that actually control explosive charge weights loaded into drilled holes by inferring the quantities of explosives loaded into blast holes were over and above that which was deemed appropriate, planned, or in accordance with MCC loading and stemming policy. This was not the case for blast HRN_08_39_OB. I therefore reject the concept of "overloading" blast holes that is misapplied to this blast as the basis for incompetent blasting.
Furthermore, the 10% variance applies only to drill pattern and loading parameters and not to charge weights loaded into blast holes. The quantities of explosives loaded into blast holes relate directly to, or are a calculated quantity of, drill pattern (drilled burden, spacing, drill holes diameter and hole depth) and loading parameters (stem length and powder factor) set forth in the Standard Fixed Patten. In the case of blast HRN_08_39_OB, the approved modified stem length of 3m was a design parameter that did not deviate and was set as a constant. Loaded explosives charge weights are not a design parameter.
I contend that MCC personnel followed procedures for loading and stemming holes in a competent manner according to written policies. The [+/-]10% variance alluded to herein does not apply to explosives weights loaded into the holes .... Rather, the variance applies to design parameters defining the drilled hole volume tempered by unforeseen and often adverse geological conditions, variations in ground surface elevation, and drilling rig performance that can enlarge holes beyond that which was planned ... explosive quantities loaded into blast holes can vary on a hole by holes basis while in the aggregate (for all holes combined) somewhat conform to the design powder factor.
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5.4.3.3 The most relevant factors not considered by the EPA in evaluating MCC's alleged noncompliance with or violation of standards or procedures are associated with the overriding non-ideal blast holes loading conditions that persist in a high percentage of blast hole in all blasting operations. Many of these conditions remain unforeseen prior to loading ... This is normal and expected in the blasting industry.
As highlighted by Mr. Willey … these conditions include variations in drill hole diameter from drill bit wear, leading to drill steel vibrations and drill bit "wobble", and variations in rock quality (voids, cavities and open factures) with depth that tend to enlarge the hole greater than the design 229mm diameter. This fact was supported by shotfirer Mr. Welch in his interview, noting hole diameters can be as much as 240mm and rarely 229mm … or 4.8% greater and can lead to loading more explosives weight than planned. …
Geology with extensive fracturing and/or containing open vugs or cavities naturally enlarge the volume inside the drilled hole. Such conditions expand hole diameters and often lead to loading more explosives than planned. Welch indicated engineers are consulted when this is evident and often air bags (air deck) are placed at the top of the explosives column and used to bring the total loaded height plus bag to the bottom elevation of the planned stem height.
Other factors that tend to change loading include the following:
• drill cuttings falling into the holes prior to or during loading,
• ground swell during rainfall reducing diameters,
• interior holes sloughing of material 1-3 days after drilling and before loading, and
• variations in explosives density available for loading especially on uneven or steep ground where bulk pump trucks cannot travel to the holes thereby being forced to load product of a different density by hose.
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5.4.3 Supporting facts
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iv. It appears that the EPA defined overloaded holes as those holes that are loaded with a higher charge weight than planned by Mr. McKenzie and submitted to MCC based on a constant 3m stem length. Planned loading well ahead of final drilling was based on estimated variable drill depth to coal, density of explosives to be loaded and a "perfect" drilled hole diameter of 229mm constant over the hole depth, along with the design stem height of 3m. Actual loading weights were written in the loading sheets by Hanwha and the weights widely varied from planned quantities as expected due to unforeseen field conditions. The only design parameter under the control of shotfirers was the stem height (3m in this case) …
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5.4.3.5 I performed a detailed statistical analysis of all available loading sheets … to verify how "19% of Blast holes for the Blast with more than 10% of the amount of explosives prescribed in the design" was determined …
i. Of the 1197 blast holes designed by Mr. McKenzie, reliable loading information available from Hanwha was obtained for 574 holes. Six holes were loaded as planned while 183 and 385 holes were loaded less than and more than planned explosive quantities, respectively.
ii. The percentage change of actual loading in kilograms (kg) relative to the design kg was computed for each hole using the following relation:
Percent change= (actual- design)/design * 100% (Equation 3)
The total number of holes loaded within and outside the +10% variance were determined and shown in Table 2. Of the 574 holes with available loading information, 72.3% were loaded within the ± 10% variance while keeping a constant 3m stem length and 109 holes (or 19%) were loaded with greater than 10% of the planned weight (+10%).
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5.4.4 Comments on Dr. Alan Cameron's opinion
Based on my independent assessments of blast hole loading as indicated on available loading sheets in comparison with planned hole loading provided by Mr. McKenzie, I agree with Dr. Cameron's opinion in section 2.2.6 that 19% of the holes with loading data were loaded with more explosive charge weight than shown in Mr. McKenzie's loading plans for an ideal drill hole diameter of 229mm and powder factor of 0.726kg/m3.
…
In my opinion, it is powder factor, along with drill pattern and hole diameter, that are the overriding design parameters for the successful, competent application of explosives. In addition to the stated design objective of a 3m stem length for blast HRN_08_39_OB, these parameters must meet the 10% allowance variance and not solely the loaded charge weights as indicated by Dr. Cameron. In my judgement MCC met the 10% allowance that applies to design parameters based on available Hanwha loading sheets by virtue that the powder factor, on which blast design parameters are based, was 2.8% higher than planned and remained well within the 10% allowed.
Dr Aimone-Martin's comments in relation to the emission of noise charge, referred to by her as charge 5, were as follows (footnotes omitted):
4.5 Charge 5: MCC carried out blast HRN_08_39_OB in a proper and efficient manner. The dealing of explosive materials and the manner in which the blast was designed with a 3m stem length and fast delay timing achieved the stated objectives of improved fragmentation, efficient and safe digging without damaging equipment and by protecting workers, and without exceeding air overpressure and vibration limits at the monitoring locations established in [the EPL]. …
Documented post-blast improved fragmentation is in direct contradiction to the EPA' s charge that explosive energy was deemed excessive and what was intended to fragment the rock was transferred into the air in the form of noise. The emission of noise from blasting is normal and expected and noise in and of itself is not an indication of improper dealing with explosives. The unusually high air overpressure measured at two seismograph locations to the southeast of the blast site resulted from unfavourable wind that focused noise in that direction. These seismographs are licensed to other mines. It is my opinion MCC did not fail to deal with explosive materials in an improper manner.
…
5.5.4 Comments on Dr. Alan Cameron's opinion
Dr. Cameron's opinion on noise emission in his November 2021 report in answer to the question as follows:
"Was the emission of noise caused by the blast the result of any failure, or failures, to deal with materials, such as explosives, in a proper and efficient manner?"
His answer was …
" ... the high level of noise/airblast overpressure from blast HRN_08_39_ OB was the result of a failure to deal with explosives in a proper and efficient manner. The combination of reduced stemming length and fast timing resulted in the premature release of a large amount of explosive energy, in the form of high-pressure gases, into the atmosphere as well as fast movement of the surface of the blast causing a large airblast to radiate out from the blast area and a large waste of explosive energy because it is not moving and fragmenting the rock mass."
I do not agree … the radiation of noise was heavily skewed by weather conditions at the time of the blast and noise did not radiate outward in a uniform and equal pattern as open-air blast wave theory predicts in the absence of preferential wind speed and direction. Dr. Cameron did not perform an assessment of wind speed and direction to explain the unusual downwind air overpressure focusing nor why uniform amplitudes of noise were not recorded at similar distances from the blast as theory would suggest. …
In her report dated 10 October 2022, Dr Aimone-Martin also referred to the results recorded at the Coomalagah monitor, and said:
5.5.3.3 In my opinion, the contravention of noise limits does not apply to monitoring locations licensed to other mines and to non-residential locations. The Tarrawonga Mine Coomalagah unit is not a seismograph licensed by MCC and therefore not subject to limits … for MCC blasts.
…
iv. The Coomalagah location is a residence considered a sensitive site but is not a noise monitoring site licenced to MCC. As such, contravention of the blast noise limit at non-MCC monitoring site cannot be considered a basis for dealing with explosives in an improper and inefficient manner when the EPL sites identified in the licence were in compliance as required in section L4 Blasting. …
Dr Aimone-Martin set out the following graph showing the sound pressure levels (dBL) against cube-root scaled distance for measurements recorded at BM1, BM2, BM3, BM4, the Coomalagah monitor, the Tarrawonga monitor and the trigger unit at the Boggabri coal mine (the Boggabri trigger unit), noting the exceedances at the Boggabri trigger unit and at the Coomalagah monitor:
Dr Aimone-Martin's graph depicted a sound pressure level greater than the 120dBL airblast overpressure limit at residences on privately owned land provided for in condition 18 of the EPA Act approval, which is based on the ANZEC guidelines, at the Coomalagah monitor (namely, 125.4dBL) and at the Boggabri trigger unit (namely, 135.6dBL).
Dr Aimone-Martin also included a summary of the weather conditions recorded by the defendant near the time of the blast which shows the average wind speed at 10:20:05am on 20 August 2020 as 19.5 kilometres per hour (km/hr) and the vector wind speed at 10:20:05am on 20 August 2020 as 19.72km/hr.
Dr Aimone-Martin said as follows in relation to weather conditions and their impact on the blast (emphasis added):
5.5.3.6 An investigation into the weather conditions at the time of the blast ... revealed unforeseeable wind direction and velocity caused focusing of noise downwind to the southeast directly in line with the Boggabri Mine Trigger unit and Tarrawonga Mine Coomalagah unit that caused unexpected noise overage …
vii. Improper use of explosives cannot explain this isolated downwind directional effect. In my opinion, the claim that improper and inefficient use of explosives materials caused isolated high overpressure is unfounded and cannot be substantiated. The exceedances at the Tarrawonga and Coomalagah units can be explained based on the local weather conditions at the time of the subject blast.
When questioned by the prosecutor about her work experience, Dr Aimone-Martin accepted that the only local mine project in which she had been involved in the period 2009 to 2020 was the "Hazelwood Project", and that that project did not involve consideration of burden relief timing in an open cut coal mine, consideration of good progressive release of burden in an open cut coal mine in Australia, consideration of stemming length of blast holes in an open cut coal mine, consideration of overloading blast holes in an open cut coal mine in Australia, or consideration of the emission of noise from an open cut coal mine in Australia. Dr Aimone-Martin accepted that of the 124 projects listed in her curriculum vitae, of those starting in 2009, only two were in relation to surface coal mines.
Dr Aimone-Martin was cross-examined as to whether she accepted that the blast vented into the atmosphere and that a large portion of the energy of the blast was lost in overpressure as follows:
Q. In the [ISEE] blaster's handbook … there's a sentence which says:
… "Energy released until products vent in the atmosphere is used in heaving the rock and probably enlarging radical fractures. Once products vent in the atmosphere, a large portion of the energy is lost in overpressure".
…
Q. You agree with those two sentences, don't you?
A. Certainly, I do.
Q. Let's look at your sentence … the "Further, the explosive energy utilised towards rock, surface rock movement and fracture was intended to be directed upward and by design into the atmosphere" …
Q. Reading your sentence, … in light of the two sentences with which you've agreed in the [ISEE] blaster's handbook, you agree that once the blast vented into the atmosphere, a large portion of the energy of the blast was lost in air over pressure? That's right, isn't it?
A. Again, we're using words like large or small. I have difficulty with that. I think in the instance of the [ISEE] blaster's handbook, we're talking about a bench blast. And on page 14 we're talking about a lifting cut. So I think the mechanism of air over pressure and its driving the fragmentation and movement of the rock is very much different between the two scenarios. So I don't agree that there was lost into the atmosphere, or the fragmentation or the movement of the rock was lost in any way.
Q. … You would agree that there would have been less overpressure if the explosive energy in the blast had been directed laterally?
A. I don't know that.
In relation to her conclusion that the fast timing was consistent with the blast being carried out in a competent manner, Dr Aimone-Martin said:
Q. Do you agree … that an … important step in your reasoning process about charge 1, that the blast was carried out in a competent manner, is your assumption that six out of the seven dot points in clause 3.3.5 [of the BLMP] were met by [the defendant]? …
A. Yes.
Q. Do you agree with me that if you're wrong about one of the six objectives that you think have been met, if that was in fact wrong, then that would affect adversely the conclusion that you've reached, do you accept that?
A. If I was wrong?
Q. Yes?
A. I would think so yes.
Dr Aimone-Martin agreed that the MIC was 56,925kg, and that that was more than ten times greater than the 5,000kg MIC that was needed in order for the blast to be in the green category of the blast hazard analysis. She agreed that the fast timing that was used for the blast and the use of two points of initiation were the cause of the high MIC and contributed to the charge weight.
In relation to the MIC, Dr Aimone-Martin's evidence was as follows:
Q. … What I'm giving you the opportunity to deal with is my proposition that a MIC of 56,925 cannot be described as conservative, you'd agree with that, don't you?
A. It's, it's - I'm not sure how I can answer that because -
HER HONOUR
Q. Well you've got to try and answer the question.
A. Yes, okay.
Q. Some of your answers have not been grappling with what's been put to you.
A. Right. You know when you say conservative, it's got to be within some metric and it's, it's certainly a charge weight that, that is, is not necessarily minimised or I could say conservative, but it is what it is for the blast intended.
LEGGAT
Q. To say it is what it is says nothing in contradiction to the proposition that it was not conservative, agreed?
A. Agree.
Q. Do you agree that the MIC was not conservative?
A. Again, what is the definition of "conservative"? I, I don't know
HER HONOUR
Q. You didn't have a problem answering question 1 in the brief of evidence to you which contains adjectives but you are having a great deal of trouble accepting other adjectives which are being put to you in cross-examination?
A. In - what was the answer to - I don't recall.
Q. "It is what it is," is what you said?
A. It is what it is, yeah, that's right.
Q. And you don't really understand the meaning of "conservative"?
A. Conservative, yes. Conservative could be a low number or it could be a high number. Conservative, to, to perform the blast the way it was intended, no, it was not conservative. For a lift and cut, it was as it should be.
Q. An MIC of more than ten times that which would put the MIC in the green column ought not to be described as conservative, do you agree with that?
A. Of ten times more would not be considered conservative?
Q. Correct?
A. Again, I, I have a hard time with that word. "Conservative" is something that's minimised, it's small. Certainly that amount of explosives is, is not small but it's, it was appropriate for that blast.
Dr Aimone-Martin accepted that in expressing her opinions in relation to the timing charge, she gave no consideration as to whether there were likely to be workers present at the Boggabri coal mine at the time of the blast, and that "Yes, of course" the likely distance of persons from the blast was a relevant matter to be taken into consideration.
In relation to the third option identified by Dr McKenzie of "3 m stemming and fast timing, and use the result as a learning opportunity, since I have doubt about the ability to reliably model the impacts on the data I have available", Dr Aimone-Martin accepted that, as at 10:02pm on 14 August 2020, the third option involved a learning opportunity.
In relation to the stemming length charge, Dr Aimone-Martin's evidence was that if the stemming length design change was not properly documented, that would change her opinion, and that in order for the blast design to be described as "competent", it was necessary for the drill and blast design checklist to be signed off appropriately. She accepted that the date was also blank, and that the date was important in relation to the matters of geology, mine planning, and blast engineering because of the iterations that the design was going through with Dr McKenzie. She also agreed that, if required, the absence of sign off by geology, mine planning and blast engineer meant that the stemming length charge was not properly documented, and that the drill and blast design checklist was not completed and that the drill and blast procedure was not "formally managed".
She also agreed that the fact that the drill and blast design checklist was not completed meant that the drill and blast design procedure had not been managed completely.
Finally, she agreed that to have a blast ratio of 13.1 compared to the ISEE Blasters' Handbook suggested ratio of between 20 and 30 demonstrated that the blast ratio was significantly less than that recommended in the ISEE Blasters' Handbook and recommended by Dr Cameron. She agreed that in that circumstance, moving from the 4.0m stemming length used in the previous blast to 3.0m was a "significant change".
In relation to the overloading charge, Dr Aimone-Martin accepted that the first step in her process of reasoning was that the 10% variance did not apply to the loaded charge weights of each individual hole; that the second step in her process of reasoning was that the 10% variance applied to the total weight of all the explosives; that is, to the design of the whole of the blast, as opposed to the design of each hole. The third step in her reasoning was that variations in the weight of explosives in each hole arose from matters such as normal wear and tear of equipment and also the presence of caverns which she described as "geological discontinuities".
Further, in relation to the overloading charge, Dr Aimone-Martin accepted that the potential danger arising from overloading a hole "can be" danger to the environment. She did not agree that the potential danger included potential danger to workers at the Boggabri coal mine.
In relation to the requirement for the blast to be carried out in a competent manner, Dr Aimone-Martin was taken to the ISEE Blasters' Handbook, and the passage at p 743 which provides that: "[i]n surface mining, the blasting engineer is faced with conflicting requirements of providing large quantities of well-fragmented muckpile that can be effectively excavated and processed and of minimizing damage to the environment". Dr Aimone-Martin agreed that what was being described there was, on the one hand, the benefit to the mine of providing large quantities of well-fragmented rock that can be excavated and processed, and on the other hand the "conflicting requirement" of minimising damage to the environment. She agreed that the blast needed to deal with that conflicting requirement in order for the blast to be carried out in a competent manner.
The prosecutor took Dr Aimone-Martin to the following hypothetical example of overloaded / underloaded holes:
In response to the hypothetical, Dr Aimone-Martin testified as follows:
Q ... Your approach to the design that you see in yellow would result in the conclusion that overloading has not occurred. Agreed?
A. That is not true. Overloading has occurred in the, in the, as by your definition, in the red holes.
Q. … Let's take it a little bit more precisely. Rather than just the red holes, do you accept that one red hole overloaded demonstrates that there is an overloading of the design?
A. For the red hole, yes.
Q. Yes. So do you accept that the blast had one or more holes overloaded?
A. Yes.
Dr Aimone-Martin was also referred to Dr Cameron's evidence in relation to the overloading of holes, including the proposition that it is possible and achievable as a matter of practicality to weigh the explosives per hole in order to achieve the integrity of the design; that is, Dr Cameron's opinion that practical steps can be taken to weigh the quantity of explosives in one hole. Dr Aimone-Martin accepted that the "weight that you put in the hole can be metered from the truck, yes. So you know how much goes in, yes", and that "if a design says "X kilos in hole 27", it's practical for that to be achieved for the reason that you've indicated".
In relation to the emission of noise charge, Dr Aimone-Martin accepted that the question she was asked to answer in her report "did not ask whether the emission of noise from Maules Creek was caused by the failure of Maules Creek to deal with the materials in a proper and efficient manner". She agreed that in answering the specific question that she had been asked, she had regard to whether improved fragmentation would result in the proper, efficient and safe mining of coal by the defendant. Also, concerning the emission of noise charge, Dr Aimone-Martin said in relation to the Coomalagah location, a residence which she accepted was a sensitive site, albeit not a noise monitoring site licensed to the defendant, and at which she appeared to accept that there was a contravention of the blast noise limit in condition 18 of the EPA Act approval, [9] notwithstanding that contravention, she was not going to take it into consideration because the Coomalagah monitor was not "licensed" to the defendant.
In relation to the Lewandowski reports and her calculations of wind speed and conclusions concerning the impact of the weather, Dr Aimone-Martin accepted that figure 2A in the first Lewandowski report (extracted above at [121]) recorded that the Maules Creek weather station showed a maximum wind speed of 5.4m/s, similar to the figures of 19.72km/hr for average wind speed and 19.5km/hr for vector wind speed used in her report. Dr Aimone-Martin said as follows in relation to the wind speed and the green, orange and red categories in the blast hazard analysis (extracted above at [116]) (emphasis added):
Q. You see … there's a reference to trigger levels green, orange and red based on the environmental blast hazard analysis … and Mr Lewandowski's point is that wind speed in the north wind conditions 270 through to 90 degrees of less than 6 metres per second is in the green category where blasting is permitted. Do you agree with that?
A. I agree.
Q. Six metres a second, you'd agree with me, is 21.6 kilometres an hour?
A. Yes.
Q. The wind was well under 21.6 kilometres an hour, wasn't it?
A. It was under, yes.
Q. The south wind conditions, 90 to 270 degrees, under 4 metres a second, which is 14.4 kilometres an hour, agreed?
A. I agree.
However, she "absolutely" did not agree with the conclusion in the second Lewandowski report that: "[o]f note is that the significant elevation in the analysed air blast overpressure levels was triggered by factors other than atmospheric conditions, pointing to other blast control measures (for example, blast design, geology, et cetera)". She testified as follows:
Based on what this kind of wind direction, which is the northwest, not the north or the south, would do at these elevated wind conditions and based on my 15, 16, 20 years' experience in modelling and monitoring air overpressure with wind conditions and my knowledge and experience.
Thirdly, the prosecutor submitted that in relation to the emission of noise charge, Dr Aimone-Martin asked herself questions different from the form of the charge. Mr Leggat said:
… Dr Cameron didn't suffer from the matters that I have put to your Honour about Dr Aimone-Martin. There appeared to be a frankness in answering questions even where the answer was helpful to the defendant. There appeared to be more objectivity in the manner that Dr Cameron answered the questions in cross-examination. Dr Cameron did not ask himself the wrong questions …
Secondly, addressing the evidence of Mr Byrnes and Ms Severin who reported ear affects following the blast to management at the Boggabri coal mine, and were taken to hospital for precautionary assessment, the defendant submitted that the Boggabri coal mine was not a sensitive receiver as defined in the Australian Standard. As such, the perceptions of two individuals in that area were "irrelevant", "even so more" in circumstances where the evidence revealed that there were 400 or more persons at the Boggabri coal mine on 20 August 2020, and only two were put before the Court, and no person at the defendant itself suffered any discomfort as a consequence of the blast.
In any event, the evidence given by Mr Byrnes and Ms Druce was "highly problematic", and any evidence given adverse to the interests of the defendant should be rejected unless supported by objective evidence. Mr Byrnes, the defendant submitted, actively sought to mislead the Court by not disclosing that he had retained solicitors to investigate a personal injury claim against the defendant, and that proceedings against the defendant had commenced. The Court would recognise that Mr Byrnes had a vested interest in giving the evidence he gave. In light of this not having been disclosed, the Court could have no confidence in the reliability of his evidence favouring his position in his common law proceedings against the defendant. Further, there was no medical evidence supporting a finding of injury, as opposed to discomfort, caused by the blast; and the documentary evidence demonstrated that Mr Byrnes had a pre-existing hearing problem, including moderate right high tone deafness likely due to exposure to gunfire as a teenager.
In relation to the evidence of Ms Druce, the defendant submitted that she is a long-term advocate against the defendant and its mining operations, and that it was "difficult to conceive of a more partisan witness". Her evidence, to the extent it had any relevance to the issues in dispute, should be viewed with "considerable circumspection".
Further, there was a more fundamental problem with the proposition advanced by the prosecutor that "actual human harm" was relevant to the question of guilt or innocence. That was because no evidence was adduced by the prosecutor which would permit the Court to find what would have occurred had some unidentified "risk assessment" or "hazard assessment" been carried out by the defendant in relation to persons at the Boggabri coal mine. Without the prosecutor having identified what any risk assessment or hazard assessment would have required the defendant to assess, and what the outcome of any such risk assessment or hazard assessment would have been, it was not possible or permissible for the Court to make a finding about whether or not the outcome would have been different.
As I have previously found, at 10:02pm on 14 August 2020, Dr McKenzie emailed Mr Williams (copying Mr Gomez and Mr Butler) in relation to his modelling of the shot, referring to "some depressing time [spent] on the modelling of this shot". In his email, Dr McKenzie referred to three options: "1. We can use fast timing and more conventional stemming lengths" 2. We can use 3 m stemming lengths and conventional timing [and] 3. We can try 3 m stemming and fast timing, and use the result as a learning opportunity, since I have doubts about the ability to reliably model the impacts on the data I have available." In relation to him having spent some depressing time on the modelling of the shot, Dr McKenzie said he was "a little disappointed, depressed" after "such a lengthy period of modelling", not having been able to come up with the answer he wanted.
As I have previously found, between 14 and 18 August 2020, Dr McKenzie undertook modelling to minimise airblast overpressure and vibration resulting from the blast at the EPL monitoring points in the north-east of the mine. In order to do so, he was supplied with the coordinates of EPL monitoring points, BM1, BM2, BM3 and BM4. At "some stage" between 14 and 18 August 2020, Mr Gomez asked Dr McKenzie to carry out modelling on a conservative basis to meet the EPL 95 percentile limits, not merely the EPL absolute limits. Mr Gomez described the approach as having "two layers of conservatism". At 11:34am on 17 August 2020, Dr McKenzie emailed Mr Butler regarding the appropriate clearance distance for the blast, taking into account both fast timing and reduced stemming. As previously found, Dr McKenzie suggested a 700m personnel clearance distance, and noted that "this blast is a departure from standard blasting practice at Maules Creek". It was not in dispute that Dr McKenzie was not asked to consider the potential impact of the blast on personnel at the adjacent the Boggabri coal mine located less than 3km to the south of the mine, with its crib hut and go line located approximately 2.9km from the proposed blast location.
In preparing the updated modelling, Dr McKenzie used data from the previous blast on 7 August 2020 to calibrate the model and make predictions for the blast. Using the previous blast's data, Dr McKenzie highlighted that the airblast overpressure level predictions were about 2dBL "higher than what was recorded at the [four EPL] monitors", and made the following comments in an email sent to Mr Gomez on 18 August 2020 at 4:43pm: "[t]he model takes into account the fast timing presented in the attached pdf file, but has not accounted for the delayed section of the blast near to the final highwall. That should only tend to reduce the levels, so I consider the estimates to be conservative from that point of view".
I find that on Thursday, 20 August 2020, at 10:22am, the defendant fired the blast which involved the loading of 1,197 blast holes with a total of 896,256kg of explosives in circumstances in which the defendant's blast design provided for the loading of a total of 854,825kg of explosives. The difference between the amount of explosives loaded and the amount of explosives provided for in the blast design was 41,404kg. This was confirmed by Ms Bulkeley's email to Mr Lund dated 31 August 2020.
In Environment Protection Authority v Grafil Pty Ltd; Environment Protection Authority v Mackenzie, [19] Preston CJ of LEC (Davies and Adamson JJ agreeing) said at [257]:
At the outset, the trial judge was in error to hold that the ordinary principles of statutory construction do not apply to construction of statutory instruments made under legislation or delegated legislation. There are not different principles for construing statutory instruments to the principles for construing legislation or delegated legislation and practical considerations do not permit a rewriting of the statutory instrument to meet what the court thinks is a sensible and practical outcome.
And in 4nature Incorporated v Centennial Springvale Pty Ltd [20] Basten JA (with whom Beazley P and Leeming JA agreed) said at [45]:
In Tovir the Court was required to construe the definition of "backpackers' accommodation", which required one to "navigate a sea of verbiage." It does not follow that there is some general principle requiring laxity or flexibility in construing delegated legislation, or statutory instruments generally. What is more, the language required to be construed in the present case was taken directly from the Planning Act, s 34B(2); it could not be said that it was "drafted less carefully than primary legislation".
Leeming JA added at [107]:
It is a general proposition that if legal language has been used less than carefully, it may be appropriate to give rather less weight to precise textual considerations. That was the point intended to be conveyed by what I said in Tovir Investments Pty Ltd v Waverley Council [2014] NSWCA 379 at [54]-[55], which commenced with an observation that "the drafter has been less than fastidiously precise in his or her choice of language" and concluded with reference to the "somewhat casually drafted internal definition". There are reasons to think that delegated legislation, or, at least, some classes of delegated legislation, may be less carefully drafted than primary legislation.
In Environment Protection Authority v Bartter Enterprises Pty Ltd (No 3) [21] (Bartter No 3) Duggan J said at [30]:
It was common ground that the EPL as a statutory instrument (s 3(1) of the Interpretation Act 1987) should be construed according to the ordinary principles of statutory construction: Environment Protection Authority v Grafil Pty Ltd (2019) 238 LGERA 147 at [257]. Thereby, requiring the provisions of the EPL and the POEO Act are to be construed according to the text, context and purpose of the relevant provisions.
In Bartter No 3, the defendant was charged with an offence against s 64(1) of failure to comply with a condition of a licence. The condition in that case provided relevantly in relation to the maintenance of plant and equipment:
O2.1 All plant and equipment installed at the premises or used in connection with the licensed activity:
a) must be maintained in a proper and efficient condition; and
b) must be operated in a proper and efficient manner. [22]
Accordingly, I proceed on the basis that an environment protection licence is a statutory instrument within the meaning of s 3(1) of the Interpretation Act and, like a development consent, must be construed in accordance with ordinary principles of statutory construction. Condition O1.1 is to be construed having regard to text, context and purpose.
The defendant submitted that some caution should be exercised in "uncritically applying" the remarks of Gleeson CJ in Genkem to the meaning of condition O1.1 here because the CCA in Genkem was considering a differently worded condition under a different statutory regime and, in the task of construction, expressly identified the significance of the statutory power pursuant to which the condition was imposed (s 17D(4) of the Pollution Control Act 1970 (NSW)), and the particular preamble included in that licence (at p 39B). In this case, condition O1.1 was imposed under the different statutory regime in Pt 3 of the POEO Act, and the EPL did not include an equivalent preamble.
However, the defendant accepted that the remarks made by the CCA in Genkem provide "some assistance at a level of generality" in approaching the construction of a condition of the general type such as condition O1.1, being a condition of a type which sets a general standard (similar in that respect to the differently worded condition considered in Genkem). The CCA's remarks in Genkem indicate that as one indicium of construction, a condition of this general type should be construed having regard to the possible environmental consequences of the acts or omissions in question.
Further, in so far as the remarks in Genkem are of general assistance, the defendant submitted that they do not support the prosecution case in relation to the charges of incompetence. The central complaint of the prosecutor was that the airblast overpressure was excessive. Consistent with the CCA's remarks in Genkem, the question of whether the blast was carried out otherwise than in a competent manner because of its noise must sensibly fall to be considered having regard to the EPL which contains specific limit conditions for noise (airblast overpressure and vibration).
The defendant submitted that the "thrust of the remarks" of Gleeson CJ in Genkem was that a condition expressed "in such general terms as would characterise [c]ondition O1.1" is within power because it is intended to deal with matters not the subject of specific provision otherwise in the licence instrument. In this case, the complaint is about the noise levels of the blast, and there are specific provisions in the EPL which address that very matter, and which were complied with, thus leaving "no sensible room" to find a contravention of the far more general terms of condition O1.1 of the EPL. [26]
Coming back to "first principles", the defendant submitted that the text of condition O1.1 is the starting point in determining its meaning. [27] The text concerns "licensed activities". The phrase "licensed activity" is not defined in the POEO Act. The word "activity" is defined in the Dictionary to the POEO Act to mean "an industrial, agricultural or commercial activity or an activity of any other nature whatever (including the keeping of a substance or an animal)". The expression "scheduled activity" is defined in the Dictionary to mean "an activity listed in Schedule 1", and "non-scheduled activity" as "an activity that is not a scheduled activity and is not scheduled development work". In the EPL, "activity" is defined to mean "a scheduled or non-scheduled activity within the meaning of the [POEO] Act". Condition A1.2 of the EPL provides that the EPL authorises the carrying out of the scheduled activities of "coal works" and "crushing, grinding or separating"; and "mining for coal", each of which activities is included in the list in Schedule 1.
On a proper interpretation of the EPL, the activities involved in carrying out a blast "may properly be said to be licensed activities". Consequently, conditions such as O1.1 and O2.1 would properly apply to the manner in which those activities are carried out and to the maintenance of plant and equipment utilised in the carrying out of those activities. On the other hand, the design of a blast, which is a separate activity to the carrying out of a blast, does not fall within the ambit of regulation under the EPL and is not a "licensed activity within the meaning of [c]ondition O1.1".
The defendant submitted that "sensibly construed", a licensed activity within the meaning of condition O1.1 is an activity (scheduled or non-scheduled) that is regulated by the EPL. Whether any particular activity is a licensed activity is a matter of construction of the licence having regard to the nature of the activity. Condition A3.1 (concerning "Other Activities") "cannot have any ambit beyond clarifying that the particular activities in the table to that condition are intended to fall within the ambit of the EPL. To the extent that condition A3.1 might be said to expand the licence so that it applies to all activities carried out on the mine, this would be legally ineffective because the "ambit of the activities that fall within the ambit of an EPL is determined by the relevant provisions of the POEO Act".
Further, the expression "competent manner," not being defined in the EPL, is to be given its ordinary meaning, informed by the text and context of the EPL and the POEO Act. [28] In construing the expression "competent manner", the defendant submitted that one should be "both cognisant of the legitimate recourse to dictionary definitions and also of the need to be careful in the adoption of them". [29] The Macquarie Dictionary defines "competence" as (i) properly qualified; capable; and (ii) fitting, suitable or sufficient for the purpose. [30]
The defendant submitted that the prosecutor's expert Dr Cameron imported "his own interpretation of competence" to condition O1.1 in asserting that the minimum requirements for a blast to be designed in a competent manner are for the designer of the blast to consider the hazards/risks for all persons potentially impacted by the blast, and to follow the processes and procedures developed for safe operations at the mine. It was that interpretation would be rejected, it not being for Dr Cameron "to import his own gloss" on the meaning of competence.
In Environment Protection Authority v Rethmann Australia Environmental Services Pty Ltd, [34] in proceedings in which pleas of guilty to contraventions of licence conditions had been entered, Talbot J considered a condition in an EPL issued by the EPA which provided as follows: "Licensed activities must be carried out in a competent manner". Talbot J at [42] held that this condition was "no more than a statement of a very general commonsense rule or duty to conduct a hazardous task in a competent manner". It was "an overarching requirement without being specific". [35] However, his Honour does not appear to have referred to either Genkem or Collex.
I find, as held in Genkem and Collex, that whether there has been a contravention of a condition in the form of the conditions considered in those cases, and condition O1.1 here, falls to be considered according to the possible environmental consequences of the acts or omissions in question. That will involve consideration of the nature of the activities and the environmental risks.
The proper construction of condition O1.1 and conditions L4.1 to L4.4 of the EPL raises, in particular, the maxims generalibus specialia derogant and generalia specialibus non derogant. Herzfeld and Prince say at 150: "[t]he maxims generalibus specialia derogant (specific provisions override general ones) and generalia specialibus non derogant (general provisions do not override specific ones) both express the primacy of specific provisions over general ones". And at 507-8:
Where a document contains general and specific provisions concerning the same subject matter, the specific provisions will prevail over general provisions to the extent of the inconsistency. This proposition is reflected in the Latin maxims generalia specialibus non derogant and generalibus specialia derogant. It is a product of construing one provision of a document with reference to the others, "based on sound common sense and appeals to everyone, layman or lawyer". It is closely related to the maxim expressum facit cessare tacitum and the principle that written or typed special clauses will be given greater weight than standard printed terms. The identification of what is general and what is specific is not determined in purely linguistic terms, but has regard to the purpose and the object of the provisions.
It is beyond controversy that where there is conflict between a general and specific provision, the specific provision prevails. [36] In Prefabricated Buildings Pty Ltd v Bathurst Regional Council (Prefabricated Buildings), [37] Robson J said at [29]:
It is important to note that where an act contains two inconsistent provisions, the general provision is to give way to the specific provision; see e.g. Perpetual Executors and Trustees Association of Australia Ltd v Federal Commissioner of Taxation (1948) 77 CLR 1 at 29; [1948] HCA 24. However, this only applies where the 'contrariety is manifest' as between the provisions; Reseck v Federal Commissioner of Taxation (1975) 133 CLR 45 at 53; [1975] HCA 38. Importantly, this rule does not apply where the specific provision adds additional powers to those contained in the general provision: Australian Securities and Investments Commission (ASIC) v Administrative Appeals Tribunal (2009) 181 FCR 130; [2009] FCAFC 185 at [78].
Here, the question is the relationship between the general provision in condition O1.1 concerning the carrying out of licensed activities in a competent manner, and the specific conditions in L4.1 to L4.4 imposing numerical limits on the levels of vibration and airblast overpressure at the four monitoring points, BM1 to BM4. It was uncontroversial that the actual results of airblast overpressure and vibration recorded at BM1, BM2, BM3 and BM4 were within the limits required under conditions L4.1 to L4.4 of the EPL.
In Weston Aluminium Pty Limited v Environment Protection Authority, [38] Pepper J in construing an EPL said at [76]: "condition O1.1, a generic condition … must be contrasted with the specific conditions". Pepper J also noted at [89] that "condition O1.1, "generic" or otherwise, is of central importance to the operation of EPL 6423". However, in her reasons, her Honour did not extract the wording of condition O1.1 there under consideration.
I accept that it is arguable that the specific conditions in L4.1 to L4.4 concerning the levels of vibration and airblast overpressure permitted from blasting operations as recorded at the EPL monitoring points are capable of overriding the general provision in condition O1.1 concerning the carrying out of licensed activities in a competent manner. However, that gives rise to the question whether conditions L4.1 to L4.4 are, in effect, a proxy for condition O1.1 in relation to the subject matter of blasting.
I am not satisfied as a matter of construction of the EPL as a whole that conditions L4.1 to L4.4 are, in effect, a proxy for condition O1.1 in relation to the subject matter of blasting, or that compliance with the limits at the four monitoring points provides a complete answer to the three s 64(1) charges. This is because:
1. Condition O1.1 directs attention to the manner in which licensed activities are carried out, and not to whether at specific locations operations otherwise achieve compliance with specific limits imposed by specific limit conditions.
2. Condition O1.1 is in Part 4 of the EPL which contains operating conditions. Conditions O1.1 is one such operating condition. Conditions L4.1 to 4.4 are in Part 3 of the EPL which contains limit conditions specifying limits not to be exceeded at particular monitoring/discharge points or utilisation areas (in the case of L2 concentration limits), at monitoring points and private residences (in the case of L3 noise limits), and at monitoring points (in the case of L4 blasting). The two parts of the EPL are concerned with distinct subject matters. I am not persuaded that contrariety is manifest as between the conditions so as to engage the maxim generalibus specialia derogant: see Prefabricated Buildings at [29] (Robson J) citing Perpetual Executors.
3. Condition O1.1 must be given work to do beyond ensuring that there is only compliance with specific limit conditions. Carrying out licensed activities in a competent manner may require the licence holder to consider matters not the subject of specific limit conditions, or in relation to which, in the particular circumstances, the specific limit conditions may not address the possible environmental consequences of carrying out the licensed activity.
4. As Prince and Herzfeld say at 507-508, the identification of what is general and what is specific is not determined in purely linguistic terms, but has regard to the purpose and object of the provisions.
5. I accept, as submitted by the prosecutor, that condition O1.1 properly construed is concerned with the general management of risk is carrying out a licensed activity having regard to the possible risk of environmental harm. The defendant accepted that the remarks of the CCA in Genkem provide "some assistance at a level of generality" in construing a condition such as condition O1.1, being a condition of a type which sets a general standard, and that the remarks indicate that a condition of this general type should be construed having regard to the possible environmental consequences of the acts or omissions in question.
6. I do not accept the defendant's submission that the design of the blast was a separate activity to the carrying out of the blast and not a licensed activity within the meaning of condition O1.1, and hence "does not fall within the ambit of regulation under the EPL". The three relevant summonses nowhere fix upon the design of the blast as an entirely separate activity to that of carrying out of the blast. Rather, each summons recognises that the design of the blast was an integral part of carrying out the blast in the course of mining for coal. It is, with respect, somewhat contrived and unrealistic to suggest that a blast of the magnitude here would be carried out, or would be sought to be carried out, in the course of mining for coal other than in accordance with a documented design and, as here, in accordance with the drill and blast design checklist.
In relation to the question of competence and incompetence, I accept the defendant's submission that the allegation in each of the timing charge, the stemming length charge and the overloading charge that "[t]he defendant did not carry out the licensed activities in a competent manner" is "logically synonymous" with an allegation that it carried out the particularised licensed activities in an incompetent manner".
However, I am not persuaded by the defendant's submission that there is a mental element or fault element required to be proved or that the principles that apply in the context of charges of criminal negligence are by analogy applicable. The test for criminal negligence involves a different inquiry, namely whether there has been such a great falling short of the standard of care which a reasonable person would have exercised.
In Principles of Criminal Law, [39] Bronitt and McSherry discuss the leading case on criminal negligence, Nydam v The Queen [40] (Nydam). In Nydam, the accused threw petrol over two women and ignited it. He claimed that he only intended to take his own life. The trial judge directed the jury as to murder and also manslaughter by criminal negligence. The accused was convicted of murder. On appeal, the Supreme Court of Victoria considered the trial judge's direction on the meaning of criminal negligence for manslaughter. The Court said at [445] that for manslaughter by negligence to be made out, it must be proved that the accused's behaviour involved:
… such a great falling short of the standard of care which a reasonable [person] would have exercised and which involved such a high degree of risk that death or grievous bodily harm would follow that the doing of the act merit[s] punishment.
In Plath of Department of Environment and Climate Change v Fish; Plath of Department of Environment and Climate Change v Orogen Pty Ltd, [41] Pain J articulated the test for criminal negligence as follows at [81]: [42]
The defendants submitted that the relevant principles (accepted by the prosecutor) as to whether they were negligent in relation to their advice was that, in the criminal context, negligence means more than a breach of a duty of care. To amount to criminal negligence, the degree of carelessness must be such as to show such a disregard for the objects of the statute as to amount to a crime against the state (R v Bateman [1925] All ER Rep 45; see also Andrews v Director of Public Prosecutions (UK) [1937] AC 576 at 583 per Lord Atkin; applied in Cittadini v The Queen [2009] NSWCCA 302 at [38]-[40]). For there to be negligence, there must have been an indifference to an obvious risk (R v Taktak (1988) 14 NSWLR 226 at 247, applied in Cittadini).
In EPA v Sydney Water (Pepper J), [43] her Honour at [169]-[191] reviewed the authorities in relation to criminal negligence (in particular, resulting in death and for manslaughter). At [188]-[189] Pepper J identified the preferable recitation of the test for criminal negligence in the context of environmental crime as follows:
188. In my view, a preferable recitation of the test for criminal negligence in the context of environmental crime is to ask whether there has been such a great falling short of the standard of care which a reasonable person would have exercised and which involved such a high risk that harm would follow that the doing of the act or the omission merits criminal punishment.
189. But irrespective of the formulation of the test in the circumstances of the present case, the evidence does not establish that Sydney Water had the necessary degree of carelessness, indifference to an obvious risk, or great falling short of the standard of care which a reasonable person would have exercised, such that criminal negligence can be established. As Sydney Water correctly submitted, just because the consequences of its actions were foreseeable this does not give rise to criminal negligence.
I do not consider that the authorities in relation to criminal negligence which have developed in a different context assist in the construction of condition O1.1 of the EPL and the words "in a competent manner". Accordingly, I do not accept the defendant's submission that there is a mental or fault element to be proved, or that the principles which apply in the context of criminal negligence are by analogy applicable.
In relation to the meaning of "competent", the Macquarie Dictionary Online [44] defines "competent" as "properly qualified; capable" and "fitting, suitable, or sufficient for the purpose".
In relation to the meaning of "manner", the Macquarie Dictionary Online defines "manner" as "way of doing, being done, or happening; mode of action, occurrence, etc". In Polgara Pty Ltd v Vision Wise Holdings Pty Ltd [45] (Polgara), Young J made the following remarks about the words "in the manner":
The words "in the manner" must be given semantic significance. Although the word "manner" may have a narrower or wider meaning depending on its context, it tends to denote the method by which a matter is handled rather than the result achieved or even the time at which it is to be achieved. It would seem that "manner" derives from the latin "manus" a hand and so denotes handling rather than producing a result.
It is sometimes difficult to draw the distinction between the procedure and the result. So in State of Alabama v Adams (1829) 2 Stewart's Alabama Reports 231 at 242, the manner of electing a sheriff did not include the provision of an official having a casting vote, which was specified in the relevant election law …
Although one must look at each use of the word in its context, the general flavour of the word "manner" is method and procedure in general, that is the nature of the procedure and the word does not necessarily connote every aspect of the procedure; Commissioner of Inland Revenue v Scott [1892] 2 QB 152, 162.
I find that the adjective "competent" in the composite phrase "competent manner" falls to be considered according to the possible environmental consequences of the acts or omissions in question. In the context of a licence authorising and regulating the carrying out of coal works, crushing, grinding or separating, and mining for coal, the nature of those activities and the possible environmental consequences of a breach of the condition of the EPL authorising and regulating their carrying out give colour and context to the meaning of "competent" in condition O1.1.
Plainly, the acts or omissions of the defendant, as holder of the EPL in question, give rise to possible environmental consequences which are, possibly, extremely serious and indeed catastrophic. The contraventions of condition O1.1 of the EPL here alleged are in no way akin to the example posited by Gleeson CJ in Genkem of a failure to store office stationery and paper clips in an efficient manner. Nor does the alleged conduct relate purely to the profitability of the defendant's business so as to be outside the purview of the condition.
Otherwise, the Macquarie Dictionary Online definition of "competent" as "properly qualified, capable" and "fitting, suitable, or sufficient for the purpose" is apposite. Likewise, in relation to the noun "manner" is the competent phrase "composite manner", I find, as opined by Young J in Polgara, that it tends to denote the method by which a matter is handled, rather than the result achieved. That approach to the meaning of manner is inconsistent with the definition in the Macquarie Dictionary Online set out above.
Further, Dr Cameron opined that "the minimum requirements for a blast to be designed in a competent manner are, firstly, to consider the hazards/risks for all persons potentially impacted by the blast, and secondly, follow the processes and procedures developed for safe operations at the mine". It was Dr Cameron's opinion that the blast was not designed in a competent manner in part because the decision to change the initiation to fast timing did not conform to one of the objectives and associated control measures in the BLMP, in particular cl 3.3.5, resulting in a high level of noise and airblast overpressure. In particular, the blast was designed based on "fast timing" which did not provide good progressive release of burden and resulted in a MIC approximately 10 times more than conservative and proven levels which was not consistent with the requirements of cl 3.3.5 of the BLMP for managing airblast overpressure.
The prosecutor further referred to Dr Cameron's opinion that the blast was not designed in a competent manner because "[i]t did not consider the potential impact on employees or facilities at the adjacent Boggabri coal mine or Tarrawonga Coal Mine". In his evidence, Dr Cameron referred to two employees at the Boggabri coal mine being injured by the noise and airblast overpressure from the blast, and that they were much closer to the blast than the residences where the blast monitors were located and the modelling was focussed. Indeed, they were approximately 2.9km from the blast, whereas the closest blast monitor (BM3) was approximately 7.5km from the blast.
In drawing her conclusion that the fast timing was consistent with the blast being carried out in a competent manner, Dr Aimone-Martin agreed that an important step in her reasoning process in relation to the timing charge was her assumption that six of the seven dot points in cl 3.3.5 of the BLMP were met by the defendant, and that if she was wrong about one of the six objectives having been met, that would adversely affect her conclusion. One of the six objectives that in Dr Aimone-Martin's view had been complied with was the objective that the MIC "is limited to conservative and proven levels". Dr Aimone-Martin accepted (based on her own calculations) that the actual MIC was 56,925kg which was more than 10 times greater than the 5,000kg MIC "trigger value" on the blast hazard analysis (extracted above at [116]). Importantly, Dr Aimone-Martin accepted that the fast timing and two points of initiation in the body of the blast were the cause of the high MIC in this case. However, in the course of answering questions about the MIC, Dr Aimone-Martin had difficulty answering questions which were premised on the use of adjectives which were not otherwise defined, such as "conservative". The prosecutor also referred to Dr Aimone-Martin's refusal to accept that a MIC more than 10 times the trigger value used in the defendant's own internal documentation, and submitted that that position could not be sustained given the other answers given by her in cross-examination.
The prosecutor also referred to Dr Aimone-Martin's acceptance that in drawing her conclusions in relation to the timing charge, she gave no consideration to whether or not there were likely to be workers present at the Boggabri coal mine at the time of the blast. Ultimately, she accepted that consideration needed to be given to the distance that persons were likely to be located from the blast.
Finally, "it was telling" that Dr Aimone-Martin's evidence was not that there was in fact "progressive [release of] burden", rather only that this criterion did not apply to the blast. If the Court accepts Dr Cameron's position that good progressive release of burden was required, then Dr Aimone-Martin's evidence did not refute the "core premise" that this was not what was provided for by the use of the fast timing in this case.
The defendant submitted that it was reasonably to be inferred that the limits imposed by condition 18 of the EPA Act approval (which requires the proponent to ensure that blasting on the site does not cause exceedances of the criteria in Table 7) derive from the recommended limits for the preservation of human comfort at sensitive receiver sites (including houses, low-rise, residential buildings, theatres, schools and other similar buildings occupied by people) as identified in the Australian Standard and as "mirrored" by effectively identical limit conditions under the EPL.
In relation to the email sent by Dr McKenzie at about 4:43pm on 18 August 2020 to Mr Gomez (addressed to "Ryan and Lee") attaching a "pdf file with modified timing suggesting levels of 113, 112, 114, and 114.8 at BM1, BM2, BM3 and BM4", the defendant submitted that it was evident from the terms of the email that by this time, Dr McKenzie had calibrated his model, Dr McKenzie stating that against the results of a previous blast, he had ascertained that his modelled predictions were about 2dB higher than the actual recorded levels.
The defendant submitted that it "emerged" from Dr McKenzie's record of interview conducted on 25 May 2021 that Mr Gomez had mentioned the biodiversity corridor to Dr McKenzie, and that to address the possibility of any material being thrown back onto the biodiversity corridor, "provision was made for the inclusion of a very large delay for the last five rows of the blast". Further, the defendant submitted, it was after Mr Gomez received Dr McKenzie's email of 18 August 2020 that he "made the final decision to opt for the fast timing option". It was "not unusual" to make a decision on the timing as proximate as this to a scheduled blast. Mr Gomez had made the decision to opt for the 3.0m stemming "possibly" two days before receiving the 18 August 2020 email from Dr McKenzie. On the "strength of Dr McKenzie's modelling and advice", the blast design was finalised to involve: electronic initiation, fast initiation timing with two centre lifts moving outward, and reduced 3.0m stemming length.
The defendant submitted that the timing charge and the stemming length charge involve allegations of incompetent design of the blast referable to timing and stemming length, and notwithstanding that Dr McKenzie was the principal architect of the timing and stemming length of the blast, the prosecutor failed to put to Dr McKenzie the allegations of incompetent design. The prosecutor had ample opportunity to cross-examine Dr McKenzie about these matters under s 38 of the Evidence Act (which concerns unfavourable witnesses) but did not do so. This diminished the weight that should be given to the prosecutor's submissions concerning the asserted incompetence the subject of the timing charge and the stemming length charge.
In any event, the defendant submitted, even if the Court were to take the view that the blast did not accord with the fifth dot point in cl 3.3.5, that would not result in a conclusion that the design of the timing of the blast failed to reach a standard of competence. The blast achieved the sole objective of the planning, design and record keeping procedure which provided that "[t]he objective of controlled blast design is to enable safe blasting of overburden and coal, while ensuring suitable fragmentation and muckpile profile to match the chosen digging equipment whilst remaining within the environmental limits set for the mine." The blast was also designed in keeping with cl 2.4 of the BLMP which provided that "[b]est practice blast management procedures will be implemented at [the mine] to achieve acceptable outcomes (in terms of rock fragmentation, ground vibration, overpressure, fly rock, dust and blast fume) ...".
The defendant submitted that to suggest that the timing was not competent by adjudging it against a standard bench blast (as Dr Cameron did) was to "miss the point", the burden relief time of 0.8-1.5ms/m having been intentionally designed to give effect to a vertical "lifting" or "centre lift" blast, the purpose of which was to achieve good fragmentation to the surface of the caprock. A design incorporating fast delay timing was necessary to achieve progressive vertical release through two lifting cuts so that internal free faces were created quickly within the centre of the blast pattern, with such upward release being required to fragment and lift the bedded caprock along the Herndale seam.
According to Dr Aimone-Martin, delay timing for bench blasting of the kind referred to by Dr Cameron is designed to achieve forward throw in the direction of the open face of the rock, with little or no uplifting of rock, instead moving rock laterally. In contrast, vertical lifting blasts, like the blast here, are designed to prevent lateral movement, instead ejecting material upward to fragment horizontally bedded caprock. Lifting blasts are designed when only one horizontal free face of relief is available to which broken rock initially moves, allowing subsequently fired holes space to move. In designing the blast, it was intended that the explosive energy move upward to direct the fracture of the caprock upwards, and as such the fast timing of the blast was necessary to achieve this. The movement of the caprock from the initial holes upward allows subsequent holes to fire as internal free faces are formed within the seam.
Further, the defendant submitted, as the blast was a lifting blast, the progressive release of burden towards a free face was not an applicable design metric. This is because the movement of caprock for a vertical lifting blast is not carried out through a progressive lateral release, as with a bench blast. As a result, the timing required for a vertically lifting blast is by necessity much faster than the progressive release timing necessary for a bench blast. The desired outcome was achieved by the blast demonstrated through the photos at figure 5 of Dr Aimone-Martin's report dated 10 October 2022 which show the large rock fragments created by the previous blast, and the fine rock fragments which resulted from the subject blast. [47]
In relation to the fifth dot point of cl 3.3.5 of the BLMP, I find established beyond reasonable doubt that the use of fast timing was such that the objective of good progressive release of burden was not met. As opined by Dr Cameron, there was not enough time for an earlier firing hole to move its rock so that a later firing hole had a void into which to move the rock. I find, as opined by Dr Cameron, that a large increase in noise/ airblast overpressure was likely to occur and foreseeable due to the very large increase in MIC and the reduction in stemming length. Fast timing resulting in a MIC of 56,925kg, 10 times greater than conservative and proven levels, was not consistent with the requirements of cl 3.3.5 of the BLMP for managing airblast overpressure. I accept Dr Cameron's opinion that the MIC is a primary contributor to vibrations and airblast levels. I reject the defendant's submission that the prosecutor's reliance on the fifth dot point in cl 3.3.5 of the BLMP somehow involved a "myopic focus" or a "fundamental misreading" of the clause, leaving only the question of whether the progressive release of burden satisfied the "loose concept of being "good"".
In relation to the sixth dot point in cl 3.3.5 of the BLMP, I find established beyond reasonable doubt that the MIC was not limited to conservative and proven levels, being more than 10 times greater than the 5,000kg MIC trigger value in the green category of the blast hazard analysis. Dr Aimone-Martin accepted that the actual MIC was 56,925kg and that the fast timing and two points of initiation were the cause of the high MIC and contributed to the charge weight. It was not to Dr Aimone-Martin's credit that she refused to answer the prosecutor's questions concerning whether the MIC of 56,925kg was conservative.
As to whether the design of the blast was a licensed activity, for the reasons set out above at [348(6)], I have found that the design of the blast is not separate from and to be distinguished from the carrying out of the blast, and is a licensed activity.
As to whether the design of the blast is properly characterised as a lifting blast or a bench blast, I have recorded above the defendant's submission that the Court will have to make an express finding as to whether or not the subject blast was a bench blast or a lifting blast, and that the entirety of the weight of the evidence upon the issue save for that of Dr Cameron supports a finding that it was a lifting blast. I cannot make a finding beyond reasonable doubt as to whether the blast is properly characterised as a lifting blast or a bench blast. However, I accept the submission of the prosecutor and find established beyond reasonable doubt that the timing used in the blast through the electronic initiation resulted in a burden relief time of 0.8-1.5ms/m. There was no dispute that the inter-row timing chosen for the blast was fast. I do not accept the defendant's submission that to suggest that the timing was not competent by judging it against a standard bench blast, as Dr Cameron did, was "to miss the point". It may be, as the defendant submitted, that the burden relief time of 0.8-1.5ms/m was intentionally designed to give effect to a vertical "lifting" or "centre lift" blast, the purpose of which was to achieve good fragmentation to the surface of the caprock. And whilst the design of a blast incorporating fast delay timing may well have been intended to achieve progressive vertical release through two lifting cuts so that internal free faces were created quickly within the centre of the blast pattern, I do not find, contrary to the submission of the defendant, that the fast timing used achieved good progressive release of burden.
Even if, accepting Dr Aimone-Martin's premise that what was required was good vertical release, rather than good progressive burden release, the fast timing that was adopted did not provide for this.
Dr Aimone-Martin accepted that if slower timing had been used in the blast, "absolutely" there would have been enough time for the earlier firing hole to move its rock into the latter firing hole so that there was a void that the rock could be moved into, and that the explosive energy then could move laterally, rather than vertically. It was not to Dr Aimone-Martin's credit that she refused to accept that as the blast vented into the atmosphere, a large portion of the blast was lost in air overpressure.
I find established beyond reasonable doubt that in programming the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m, the defendant failed to carry out the blast in a competent manner in contravention of condition O1.1 of the EPL. The programming of the electronic initiation system for the blast was not "fitting, suitable or sufficient for the purpose". That the blast otherwise complied with the limit conditions in L4.1 to L4.4 of the EPL for airblast overpressure and vibration does not detract from this finding. As I have set out above at [348], I do not consider the limit conditions in L4.1 to L4.4 to be, in effect, a proxy for condition O1.1 in relation to the subject matter of blasting. It does not follow that I find that Dr McKenzie fell short in the modelling he was tasked to perform, namely to predict vibration or overpressure levels at the four EPL monitoring points. I find, as submitted by the defendant, that Dr McKenzie's email to Mr Butler in response to Mr Butler's email sent at 10:47am on 18 August 2020 demonstrated that Dr McKenzie was then satisfied with the timing based on the modelling, and that the prosecutor put no contrary submission to him. However, it is evident that Dr McKenzie himself harboured doubt as at 10:02pm on 14 August 2020 as to whether he could reliably model the impacts of the blast at the four EPL monitoring points.
I also find, as opined by Dr Cameron, that the blast design did not meet the first paragraph of section 4.1 of the Australian Standard which requires that all blasts shall be planned and designed to achieve the required outcome with first consideration being the protection of persons, property and the environment. Nor, I find, did the blast design meet the second paragraph of section 4.1 that before the commencement of any blasting operation an investigation of the site and its environs shall be carried out, identifying any potential hazards/risks. Whilst I accept the defendant's concern in relation to damage from inadequate fragmentation and the risk of injury, I find that in failing to consider the hazards/risks for all persons potentially impacted by the blast, in particular employees at the Boggabri coal mine significantly closer to the blast than where the defendant's EPL monitoring points were located, as well as at the Tarrawonga and Coomalagah monitors, the defendant failed to carry out the blast in a competent manner in contravention of condition O1.1 of the EPL.
The prosecutor has established, beyond reasonable doubt, that the defendant committed an offence against s 64(1) of the POEO Act by contravening condition O1.1 of the EPL in programming the electronic initiation system for the blast with a burden relief time of 0.8-1.5ms/m which did not provide for good progressive release of burden.
As to Dr Cameron's analysis of the blast ratio (set out above at [404]), in cross-examination, Dr Aimone-Martin agreed that to have a blast ratio of 13.1 compared to the ISEE Blasters' Handbook suggested blast ratio of 20 to 30 indicated that the blast ratio was significantly less than that recommended in the ISEE Blasters' Handbook and by Dr Cameron. Dr Aimone-Martin further agreed with Dr Cameron's characterisation of the movement from a 4.0m to a 3.0m stem as a "significant change". Dr Cameron noted that the reduction in stemming length of 4.0m utilised in the previous blast to 3.0m was 25%, and this meant that the "confinement on the explosive charge" during the blast was also reduced by 25%.
The defendant also referred to Dr Cameron's report in which he opined that the reduced stemming length coupled with the fast timing used by the defendant "resulted in the premature release of a large amount of explosive energy, in the form of high-pressure gases, into the atmosphere as well as fast movement of the surface of the blast causing a large airblast to radiate out from the blast area and a large waste of explosive energy". The defendant submitted that Dr Cameron's "allegations" in this regard were not supported by analysis and calculations. In addition, there was no evidence of any waste of explosive energy. The blast effectively improved fragmentation along the Herndale seam "in direct contradiction to the assertion that explosive energy was deemed excessive". The defendant submitted that the prosecution could not establish beyond reasonable doubt that the defendant was not competent in its performance of the blast based on the use of a 3.0m stemming length which deviated from the standard. On the contrary, there was evidence that the defendant "carefully planned and designed the blast", including the 3.0m stemming height (or length), in consultation with Dr McKenzie and "through conducting appropriate predictions and modelling".
Additionally, the stemming length charge was a complaint about the design of the blast. For the reasons previously recorded at [385]-[386] above, the defendant submitted that the blast design was not a "licensed activity" within the meaning of condition O1.1 of the EPL, and that the charge must also fail on that basis.
I find established beyond reasonable doubt that in utilising a 3.0m stemming length for the blast holes which deviated from the design standard which specified a stemming length of 3.5m, the defendant contravened condition O1.1 of the EPL. The changes to the stemming length did not comply with the BLMP in relation to the management of airblast overpressure.
The stemming length utilised in the blast involved a 14% reduction in stemming length compared to the design standard of 3.5m. It was not in contest that the 3.0m stemming length for the blast deviated from the design standard. As opined by Dr Cameron, by reference to the ISEE Blasters' Handbook, the reduction from the design standard of 3.5m was a "significant change" and a "concern". As Dr Cameron opined, the stemming length in the design standard was developed based on the mine's experience and its safe operation and the stemming length reduction did not comply with the BLMP in relation to the management of overblast pressure, and was not "fitting, suitable or sufficient for the purpose", having regard to the possible environmental consequences.
Again, as in relation to the timing charge, I find that utilising a stemming length of 3.0m for the blast holes and in failing to consider the hazards/risks for all persons impacted by the blast on particular employees at the Boggabri coal mine significantly closer to the blast than the residences where the defendant's EPL monitoring points were located, as well as at the Tarrawonga and Coomalagah monitors, the defendant failed to carry out the blast in a competent manner in contravention of condition O1.1 of the EPL.
It is true that around the time of the blast the concept of reducing stemming length to address fragmentation was not a new concept. In his December 2019 report, Dr McKenzie had recommended stemming length in the range of 3.0m to 3.5m for hard rock areas. However, as Dr McKenzie accepted, the recommendations in his December 2019 report had not been adopted by the defendant.
I have addressed the defendant's submission that the design of the blast was not a "licensed activity" within the meaning of condition O1.1 of the EPL above at [348(6)].
The prosecutor has established beyond reasonable doubt that the defendant committed an offence against s 64(1) of the POEO Act by contravening condition O1.1 of the EPL by utilising a stemming length of 3.0m for the blast holes which deviated from the defendant's design standard which specified a stemming length for the blast holes of 3.5m.
The prosecutor submitted that Dr Cameron's evidence was that practical steps can be taken to ensure that the weight of explosives in a particular hole is kept consistent with the design weight for that hole. In his report dated 4 November 2021, Dr Cameron explained that this is "achievable and common practice because the bulk explosives delivery trucks have measurement systems that accurately track and control the amount of explosives loaded in each hole and the truck operators have the load sheets with the designed weight to be loaded in each hole".
In relation to the third step in Dr Aimone-Martin's logic concerning the overloading charge, in her written evidence Dr Aimone-Martin suggested that the variations in the loading values were by reason of unavoidable hole diameter enlargement resulting from the normal and expected drill positioning and alignment on uneven surfaces, bit wear, drill rod vibrations and unforeseen geological discontinuities, voids and vertical variations in rock strength. The prosecutor submitted that Dr Aimone-Martin's evidence on this topic "misse[d] the point" that the variations might explain why the volumes of any blast hole might deviate from the design, there remaining the step as to how the hole should be loaded and a requirement to keep that loading within the 10% variance; that is, the prosecutor submitted, the question of how much explosive should be loaded into any blast hole, particularly where, as here, an overloaded hole creates a safety issue. Further, Dr Aimone-Martin accepted Dr Cameron's opinion that practical steps can be taken to weigh the quantity of explosives in one hole; that is, the weight that can be put in the hole can be "metered" from the truck and the amount delivered known so that it is possible to conform with what is required by the blast design.
Finally, the prosecutor submitted, in assessing Dr Aimone-Martin's evidence in relation to the overloading charge, the Court should take note of the fact that at various points during cross-examination, she did not engage with and had to be directed to answer questions.
The defendant submitted that the individual holes the blast were designed to be 3.0m in stemming length with a hole diameter of 229mm. While there was some variation in the quantity of explosives in individual blast holes, this was, according to Dr Aimone-Martin, normal and influenced by field conditions such as unforeseen and often adverse geological conditions, variations in ground surface elevation, and drilling rig performance that can enlarge holes beyond that which was planned. The defendant submitted that the quantity of explosives in individual holes "can and often does vary because the holes cannot possibly be entirely uniform based on geological conditions".
The defendant also referred to the evidence given by the shotfirer, Mr Willey, as demonstrating that the loading of the holes was dictated by the planned stem length of 3.0m and diameter of 229mm, and not by the weight of the explosives in each hole. The planned loading quantities were based on "a perfectly dug hole 3.0m deep and 229mm in uniform diameter", however in practice, the holes were dug subject to geological conditions, equipment accuracy, ground swell from rain, amongst others. The defendant submitted that the total quantity of explosives used in the blast was designed by Dr McKenzie to achieve a 0.726kg/m3 powder factor. Calculations performed in Dr Aimone-Martin's report dated 10 October 2022 were based on an analysis of the loading information for the holes making up the blast and demonstrated that the actual loading for all holes in the aggregate resulted in an as built powder factor of 0.744kg/m3. This was a 2.5% increase in powder factor than that set out in the blast design, and well within the 10% allowance calculated across the aggregate holes for the blast set out in the blast planning, design and record keeping procedure.
It was "not correct", the defendant submitted, as was contended by Dr Cameron, that each drill hole must represent less than a 10% variance from the blast design in terms of actual weight of explosives in each hole. This failed to consider the realities of drilling conditions and the design parameters of the blast which were stemming height, hole diameter and powder factor, rather than quantity of explosives per hole. Further, as there was no metric in the design of the blast based on the quantity of explosives loaded into each hole, failure to adhere to such a metric could not be used to establish a lack of competence on the defendant's part in failing to meet that design parameter. The defendant's procedures did not require compliance with such a metric. The blast holes for the blast were not overloaded beyond what can be considered to be a "reasonable and expected tolerance based on variances which pertain to specific blast sites". The prosecutor could not establish beyond reasonable doubt that the defendant was not competent in performing the blast in that it overloaded the blast holes beyond the 10% allowance within the defendant's procedures.
In oral submissions, Mr Howard for the defendant referred to the hypothetical example that was put to Dr Aimone-Martin as "puzzling", and said as follows:
That hypothetical didn't demonstrate anything. If we're looking at the substance of Dr Cameron's theorem, … there's no suggestion that there was any geographical pattern to the overloaded holes. None whatsoever. So the Court can only conclude that the 19% of holes overloaded - putting to one side the percentage underloaded - according to Dr Cameron's theorem are somehow interspersed across that bench that you've seen in the photos. What possible consequences is that alleged to have had? Nothing. Nothing. Would your Honour find, then, that to ground a criminal charge of incompetence? We submit not.
We submit that if there'd been overloading of the type that I described as the hole shot to the point that really played materially with the powder factor, maybe. If there was a geographical pattern that meant there was going to be a risk of flyrock going into a Garden of Eden of the green type in the hypothetical next to the holes. There's nothing like that. So what you're left with, when your Honour looks at the substance of it and is not distracted by a competition as to what is the best definition of "overloading", your Honour will be … bereft of any rational basis to ground a finding that this is incompetent.
Mr Howard also submitted that the particulars of the overloading charge had not been made out:
… you'll recall that Dr Cameron's evidence was that this was in contravention of two procedures. But he subsequently accepted in cross-examination that neither of the procedures to which he referred in fact imposed any requirement of the type he had suggested in relation to restricting the load to 10% - no more than 10% more than the charge weight.
Mr Gomez' view as at August 2020 was that if the total kg of the blast exceeded the design by 10% "you could say the shot's overloaded". Mr Gomez said "if there was 1,000 kilos in the whole blast and you had over 11 hundred for the whole blast, my view was you could say the blast was overloaded".
Again, as in relation to the timing charge and stemming length charge, I find that in overloading the blast holes and in failing to consider the hazards/risks for all persons potentially impacted by the blast, in particular, employees at the Boggabri coal mine located significantly closer to the blast than the private residences where the defendant's EPL monitoring points were located, as well as at the Tarrawonga and Coomalagah monitors, the defendant failed to carry out the blast in a competent manner in contravention of condition O1.1 of the EPL.
I have addressed the defendant's submission that the design of the blast was not a "licensed activity" within the meaning of condition O1.1 of the EPL above at [348(6)].
The prosecutor has established beyond reasonable doubt that the defendant committed an offence against s 64(1) of the POEO Act by contravening condition O1.1 of the EPL by failing to carry out the licensed activity in a competent manner by overloading approximately 19% of the blast holes with more than 10% of the amount of explosives prescribed in the design for the blast in contravention of the defendant's loading and stemming blast holes procedure.
On appeal, in Bartter Enterprises Ply Ltd v Environment Protection Authority [49] (Bartter CCA), Basten JA considered the history of the phrase "proper and efficient" in the context of environmental legislation as follows (footnotes omitted):
[20] It is convenient to start by identifying the scope of the qualifying phrase "proper and efficient", which appears in both paragraphs. It is a phrase which has a history, as used in environmental control legislation. The trial judge referred in her reasons to Genkem Pty Ltd v Environment Protection Authority, a judgment of this Court in 1994 dealing with offences under the Clean Waters Act 1970 (NSW), the Clean Air Act 1961 (NSW) and the Pollution Control Act 1970 (NSW). ln particular, Genkem held a licence under the Pollution Control Act which stated:
CONDITIONS For the purpose of preventing, controlling or mitigating the pollution of the environment, this licence is granted subject to the following conditions:
…
L6 Matter and substances on the premises shall be processed, handled, moved and stored in a proper and efficient manner.
Section 14(3) of the Clean Air Act created an offence committed by an occupier of certain kinds of premises who caused air pollution "by reason of his failure to process, handle, move or store those materials in a proper and efficient manner."
[21] In dealing with the licence condition, Gleeson CJ stated:
When regard is had to the legislative power pursuant to which condition L6 was imposed, and to the preamble to the licence conditions quoted above, as well as to the immediate context of the condition, it becomes reasonably apparent that the reference to ' matter and substances' is a reference to matter and substances capable of polluting the environment. ... For the same reasons, an issue as to whether there had been failure to deal with matter and substances in a proper and efficient manner would fall to be considered according to the possible environmental consequences of the acts or omissions in question. Conduct which had no possible environmental consequences, but was related solely to the profitability of the appellant's business, would be outside the purview of the condition.
[22] There was challenge in Genkem to the validity of the licence condition on the basis of its uncertain operation. In rejecting that challenge, Powell JA stated:
"[W]hile the words 'efficient manner' and 'proper and efficient manner' may, when standing alone, be of uncertain content, they are capable of taking colour from the context in which they are used, it following, in my view, that when used in the context or statutes such as those with which we are now concerned, they carry with them the flavour or 'use in such a manner as to prevent or to minimise pollution or the risk or pollution' .
…
[24] Consistently with Genkem, the phrase "proper and efficient" in condition O2.1 must be understood as referring to the maintaining of plant and equipment and the use of plant and equipment having regard to possible environmental consequences arising from failure to maintain or use the plant and equipment in such a way as to minimise or avoid those risks. It was not in dispute that release of ammonia into the atmosphere was a relevant environmental consequence which was to be avoided.
[25] It is evident that there is no bright line to be drawn between the circumstances in which par (a) [of the standard condition: i.e. "must be maintained in a proper and efficient manner"] may be engaged and those in which par (b) [of the standard condition: i.e. "must be operated in a proper and efficient manner"] may be engaged. That is, the manner of operation of the plant must be assessed in relation to its condition, which may, in turn, be dependent upon the way in which the plant is expected to be operated. Further, par (a) refers to maintaining the plant in a particular condition, rather than carrying out maintenance work on the plant. That is consistent with the purpose of the licence which is to protect the environment from harm. Risks may inhere in plant and equipment whether or not it is in active operation. Faulty electrical wiring, for example, may pose a risk of fire even if the plant is not in use. If a fire breaks out during the operation of the plant, for example when a switch is operated, it may be possible to characterise the cause of the fire as an act undertaken in the operation of the plant, but the cause is also the faulty condition of the electrical system.
The prosecutor also referred to s 120 of the POEO Act (offence of water pollution) to which s 122(1) provides a statutory defence, and also to s 142A (offence of pollution of land) which is also subject to a statutory defence in s 142C (that the conditions of an EPL were not contravened), and submitted that Parliament's decision not to provide for a similar statutory defence for noise pollution offences is a strong reason why the Court should not interpret s 140(1) as having "any sort of implied exception or defence that is based upon what is allowed under the conditions of an EPL". Accordingly, it is not a defence "to prove the charge to otherwise be in accordance with any limits of vibration or overpressure that are set out in an EPL". The prosecutor identified two limits placed upon the operation of s 140(1) by its terms:
1. there is an emission from the premises; that is, the noise occurs outside the premises; and
2. there is a causation requirement in the terms of the provision, that is the emission of noise must be caused by the failure to deal with the materials in a proper and efficient manner.
The prosecutor submitted that the third reason (the inefficient use or waste of explosive energy) also supported Dr Cameron's conclusion that it was not correct to conclude, as Dr Aimone-Martin did, that the approach adopted achieved both compliance with the EPL and improved rock fragmentation. Dr Cameron opined that there were other options available to the defendant to achieve EPL compliance and to increase rock fragmentation, particularly where the defendant knew and was advised of the risks inherent in the course that was adopted, and did not seek advice from Dr McKenzie in relation to the risks to personnel at the Boggabri coal mine. Dr Aimone-Martin's attention was drawn to the fact that the question she had been asked was whether the materials were dealt with in a proper and efficient manner generally, and that she was not directed towards the language of s 140(1) of the POEO Act, the relevant statutory provision. Dr Aimone-Martin accepted that she was not asked whether the emission of noise from the mine, or any part of it, was caused by the failure of the defendant to deal with the materials in a proper and efficient manner.
The prosecutor also referred to Dr Aimone-Martin's acceptance that when she opined that the materials had been dealt with for the purpose of achieving rock fragmentation and "the safety of equipment and equipment operators", her consideration of the safety of the equipment operators was limited to operators at the mine. She also appeared to accept that although the Coomalagah location is a sensitive site and there was a contravention of the blast noise limit in condition 18 of the EPA Act approval at that sensitive site, she did not consider it necessary to take this into account in forming her view that the materials were dealt with in a proper and efficient manner.
Further, the prosecutor referred to one of the other reasons given by Dr Aimone-Martin in concluding that the materials were dealt with in a proper and efficient manner, namely that the radiation of noise out from the blast was heavily skewed by the weather conditions at the time of the blast. The "conclusions to the contrary" in the Lewandowski reports were put to her in cross-examination, and although she accepted that she had made the same calculations as to the wind speed (which placed the meteorological conditions in the green category in the blast hazard analysis), she had come to the opposite conclusion as to the impact of the weather at the time of the blast. The prosecutor submitted that Dr Aimone-Martin "gave no explanation for coming to the opposite conclusion and her evidence on this point should not be accepted".
In oral submissions, the prosecutor referred to the fact that the blast was originally scheduled for 19 August 2020, but was called off, and submitted that if the atmospheric conditions on 20 August 2020 were also such that the blast could not proceed, the blast should also have been called off. Further, the prosecutor submitted that the "atmospheric conditions relate to dispersion of the noise whereas importantly the charge relates to [emission] from the premises, so all the noise for the purpose of the s 140 charge is required to do is to pass the boundary of the premises in order for that element of the s 140 charge to be established". Whether the noise is dispersed by atmospheric conditions or not was not relevant to the charge.
The defendant submitted that the prosecutor had failed to establish a causal connection between the noise caused by the blast and the alleged failure on the part of the defendant to deal with the explosives in a proper and efficient manner. The charge as particularised was submitted not to be a charge that the explosion was louder than it might otherwise have been by reason of the defendant opting for 3.0m stemming and the fast timing, rather it was an allegation that this manner of dealing with the explosives caused "all of the noise of the explosion".
[2020] NSWLEC 114 at [30] (Duggan J).
See Bartter No 3 at [40]-[48] (Duggan J), cited with approval in Environment Protection Authority v Charlotte Pass Snow Resort Pty Ltd [2021] NSWLEC 37 at [121] (Pepper J). See also Environment Protection Authority v Sydney Water [2022] NSWLEC 100 at [82] (Moore J).
[2011] NSWLEC 39 at [65] (Craig J).
(1994) 85 NSWLR 33; (1994) 85 LGERA 197 (Gleeson CJ) (Dunford J and Powell JA agreeing).
Apart from Collex, the defendant referred to other sentencing decisions of this Court following pleas of guilty for s 64 POEO Act offences for admitted contraventions in the form of condition O1.1 and submitted that "little, if any, assistance for present purposes is to be derived from any of the sentencing remarks" in those cases. See Environment Protection Authority v Hardman Chemicals Pty Ltd [2020] NSWLEC 8 (Robson J); Environment Protection Authority v GrainCorp Operations Limited [2019] NSWLEC 143 (Pepper J); Environment Protection Authority v Sydney Water Corporation [2019] NSWLEC 100 (EPA v Sydney Water (Pepper J)) (Pepper J); Environment Protection Authority v Whitehaven Coal Mining Ltd (2019) 239 LGERA 31; [2019] NSWLEC 27 (Pepper J); Environment Protection Authority v Signium Pty Ltd (2018) 239 LGERA 1; [2018] NSWLEC 126 (Moore J); Environment Protection Authority v Wambo Coal Pty Ltd [2017] NSWLEC 152 (Pain J); Environment Protection Authority v Warkworth Mining Ltd (2017) 227 LGERA 145; [2017] NSWLEC 107 (Moore J); Environment Protection Authority v Dyno Nobel Asia Pacific Pty Ltd [2017] NSWLEC 64 (Moore J); Dyno Nobel Asia Pacific Pty Ltd v Environment Protection Authority (2017) 228 LGERA 55; [2017] NSWCCA 302 (Simpson JA, R A Hulme and Wilson JJ); Environment Protection Authority v Hawkesbury City Council [2017] NSWLEC 39 (Pain J); Environment Protection Authority v Elf Farm Supplies Pty Ltd [2017] NSWLEC 60 (Sheahan J); Environment Protection Authority v Environmental Treatment Solutions Pty Ltd [2015] NSWLEC 160 (Pepper J).
Environment Protection Authority v Bartter Enterprises Pty Ltd (No 3) (Bartter (No 3)) [2020] NSWLEC 114 at [40] (Duggan J).
Bartter (No 3) at [40] (Duggan J).
As discussed in House of Peace Pty Ltd v Bankstown City Council (2000) 48 NSWLR 498; (2000) 106 LGERA 440; [2000] NSWCA 44 at [28]-[33] (Mason P).
Macquarie Dictionary (2019, Pan Macmillan Australian Pty Ltd).
On day 13 of the trial, senior counsel for the prosecutor said that "[t]here is a continuum where incompetence is at one end, at the other end is a competent manner, and lying between is a failure to carry out in a competent manner" (the continuum proposition), however the continuum proposition was not pressed by the prosecutor in final address.
Citing EPA v Sydney Water (Pepper J) at [169]-[191] (Pepper J).
(1994) 35 NSWLR 33 at 41; (1994) 85 LGERA 197 (Gleeson CJ) (Powell JA and Dunford J agreeing).
Cited in Environment Protection Authority v Buchanan (No 2) (2009) 165 LGERA 383; [2009] NSWLEC 31 at [76] (Pain J).
Perpetual Executors and Trustees Association of Australia Ltd v Federal Commissioner of Taxation (1948) 77 CLR 1 at 29; [1948] HCA 24 (Perpetual Executors) (Dixon J).
[2017] NSWLEC 44 at [29] (Robson J).
[2021] NSWLEC 131 at [76] (Pepper J), appealed but on a different point.
Bronitt and McSherry, Principles of Criminal Law (4th ed, 2017, Thomson Reuters).
[1977] VR 430 (Young CJ, McInerney and Crockett JJ).
See also EPA v Sydney Water (Pepper J) at [170] (Pepper J); Chief Executive, Office of Environment and Heritage v Orica Pty Ltd; Environment Protection Authority v Orica Pty Ltd [2015] NSWLEC 109 at [114] (Preston CJ of LEC).