Floods

Under the pump

In the lead-up to the 2010-11 Queensland floods that overwhelmed that State’s mining industry, only one mine operator conducted an audit, upgraded infrastructure and installed new pumps, writes Tracey Mackay.

While Queensland experienced a record-breaking and unprecedented level of rain from December 2010 to January 2011, it seems many mines were simply underprepared for anything above moderate flooding. This was despite the fact the Bureau of Meteorology had forecast the high possibility of a significant wet weather event that season. Many mine operators claimed to be unaware of the scale and severity of the Bureau’s forecast, despite the information being readily available.

With severe and unpredictable weather events on the rise, the importance of having adequate water infrastructure and pumping equipment in place in the lead up to the wet season was highlighted in the Queensland Floods Commission of Inquiry.

Following is how the Queensland Floods Commission of Inquiry summarised events:

Prolonged rainfall over Queensland’s mining regions during the 2010/2011 wet season severely affected the industry. Huge volumes of water poured into pits and leaked into underground areas. Following years of drought, some mines had been designed to catch as much runoff as possible.1 Storage facilities and dams became so full that operators were forced to pump excess water into pits.2 Access to equipment, storage facilities and monitoring sites was cut.3 Gigantic mining equipment was swamped by floodwaters.

Eighty-five per cent of Queensland coal mines had to either restrict production or close entirely.4 In May 2011, Queensland’s coal mining sector had recovered to only 75 per cent of its pre-flood output.5 The economic repercussions of these events were a loss of $5.7 billion 6 (2.2 per cent)7 in Queensland’s gross state product for the financial year ending June 2011, and a reduction in royalties received by the Queensland Government.

The Commission received many submissions from mining companies and the Queensland Resources Council concerning the actions, and in-actions, of the Queensland Department of Environment and Resource Management (DERM). The complaints ranged from “delays, impossible conditions and an agency hesitant to take an expansive view of its powers to assist their recovery.”10

Environmental groups were concerned that the State’s waterway ecosystems were harmed due to DERM’s poor decision-making. In its own defence DERM claimed it had “struck an appropriate balance between the competing interests by allowing the release of water from mines under strict conditions.” 12

Following is the Commission’s response to the submissions:

Those submissions were the impetus for a confined examination of DERM’s response to flooding at mine sites and the use of its legislative powers under the Environmental Protection Act. The Commission has not conducted a comprehensive investigation into the mining industry in Queensland. The fact that only a limited number of recommendations are directed at mining companies should not, therefore, be interpreted as an endorsement of existing flood preparedness and response activities within that industry.

In order to examine DERM’s response, the Commission selected seven case examples:

  • Hail Creek mine, operated by Rio Tinto Australia, an open cut coal mine situated near Mackay13
  • Rolleston mine, operated by Xstrata Coal Queensland, an open cut thermal coal mine located 275 kilometres due west of Gladstone, approximately 16 kilometres from the town of Rolleston14
  • the Ensham mine, an open cut coal mine approximately 40 kilometres east of Emerald in Central Queensland15
  • the Moranbah North mine, operated by Anglo American Metallurgical Coal Pty Ltd, an underground coal mine 15 kilometres north of Moranbah16
  • the Dawson mining project, also operated by Anglo American Metallurgical Coal Pty Ltd, a collection of three open cut coal mines (Dawson South, Dawson Central and Dawson North) located near Moura17
  • the Moranbah Gas Project, operated by Arrow Energy, a site used for the extraction and processing of coal seam gas, situated on the Isaac River 2.5 kilometres from Moranbah18
  • the Century mine, operated by MMG Century, 250 kilometres north-west of Mt Isa, which produces lead and zinc concentrates.19

“(the Commission) also pointed to a range of simple measures, such as checking and installing new pumps, that could be done easily and quickly without a wet weather crystal ball”.

Preparation for the 2010/2011 wet season

The Commission spent many months investigating how each of these case study mines prepared for, and reacted to, the 2010-2011 floods:

Preparation for flooding at a mine site begins well before the wet season. Mine operators are required to produce water management plans for DERM’s approval. Mines are able to deal with excess water in a range of ways, including building infrastructure such as water storage and tailings dams, desalination and treatment plants and diversion channels. Emergency action plans and flood procedures may be developed. A mine operator’s preparation for flood may include audits of the operator’s capacity to respond quickly to flood and checks to ensure equipment, such as pumps, are functional. There has been no attempt to consider whether all such measures were appropriately adopted at each mine site – that would be a formidable task.

The Commission has focussed on the two aspects of preparation that were squarely raised on the material before it: the response to the Bureau of Meteorology’s forecast in October 2010 that above median rainfall was expected for much of Queensland, and DERM’s pre-wet season inspections.

Response to Bureau of Meteorology seasonal forecast

Surprisingly, not all of the operators of case study mines were aware that the Bureau of Meteorology had forecast that the 2010/2011 wet season was likely to involve above median rainfall. None was provided with the seasonal forecast by DERM, or the Bureau itself.27 The forecast was available on the Bureau’s website. It is not DERM policy to provide forecast information to operators.28

It was not until December 2010 that Rio Tinto, for example, realised that a significant wet season might be approaching.29 The operators of Century mine were aware of the general thrust of the Bureau’s forecast in the second half of 2010, but had no specific advice about the Gulf region in which that mine is located.30 Others did obtain and use forecast information: from March 2010, Xstrata had a staff member reviewing and distributing to employees publicly available weather forecast information for the Rolleston coal mine, including seasonal, weekly and daily forecasts.31

Very few specific actions were taken by the operators of the case study mines in response to the Bureau forecast.

One operator which did react was Anglo American; it undertook a pre-wet season review at its Capcoal mine which identified risks and recommended infrastructure upgrades,32 in consequence of which Anglo purchased additional pumping equipment.33

Most companies took at least some action to implement their water management plans and deal with issues arising from previous wet seasons. Ensham, which had experienced significant inundation in 2008, constructed levees to protect it from a flood with an average recurrence interval of 1000 years in the Nogoa River.34 It had also installed additional pipe infrastructure.35 Arrow Energy was building additional dams and planned to build a water treatment plant.36 Xstrata implemented a system of levees and diversion channels to move water away from mine pits,37 and responded to shortterm forecasts of rainfall of over 50 millimetres by checking diversion channels and pumps and blocking off ramps that might allow water to enter operational pits.38

Water in mining

The Commission examined the role water plays in mining and how it may affect the environment if not properly managed:

Water is required to undertake most mining activities. Coal miners use it to process and wash coal and suppress dust.20 At coal seam gas projects, saline water is extracted from coal seams in the process of obtaining the gas.21 If the gas is not exiting the coal seam quickly enough, water is used in ‘fracking’, a process in which water is inserted into coal seams at high pressure to fracture the rock, allowing the gas to escape.22 Other types of operations, such as the Century lead and zinc mine, use water to separate minerals from a slurry of mined ore.23

Whatever role it plays, water used in, or resulting from, mining operations is likely to come into contact with contaminants, such as salts and metals.24 As a result, it will often be of lower quality than fresh water in rivers and creeks. In light of water’s status as a tool used in mining operations and a product of such activities, most mines have facilities to store both fresh water and contaminated, or mine-affected,25 water.

While the Commission accepted that many mines owners felt they had no time to prepare for such high levels of flooding, it also pointed to a range of simple measures, such as checking and installing new pumps, that could be done easily and quickly without a wet weather crystal ball:

  • Representatives from MMG Century and Anglo American indicated that seasonal forecasts did not provide enough lead time to build infrastructure to cope with flooding.39 That is true for long term solutions to the threat of flood.
  • Other measures, such as checking pumps and drainage channels or auditing response capability, do not require such lead times.
  • Knowledge of forecasts can help operators to prepare for the wet season ahead, for example by preparing applications for transitional environmental programs and opening lines of communication with DERM.
  • Mine operators should take primary responsibility for obtaining and reviewing the best forecast information available. It would be sensible for operators of sites at high risk of flood to obtain region specific forecast information (both seasonal and short-term) directly from the Bureau of Meteorology. The Bureau does provide such a service for some mines currently.40

Flooding at mine sites

Following is the Commission’s report on how each of the case study mines was affected by flooding and how they addressed the situation at the time.

Hail Creek Mine

At the end of December 2010 at Hail Creek mine, water storages were calculated to be approximately 98 per cent full; by the end of January 2011, the storage facilities were at 105 per cent capacity.49 The mine was storing approximately seven gigalitres of water onsite in dams and pits.50 Water was continually pumped from high priority areas into low priority areas around the site in an effort to maintain some operations.51 Rio Tinto sought, and was granted, authorisation by DERM to release water into surrounding watercourses in January 2011.52 All sale contracts were suspended by reason of the wet weather from 24 December 2010.53 Pits used for the purpose of storing water were unable to be mined until dewatering activities had begun; supplies of explosives were delayed; and resources were being deployed to address the water located in the pits.54 The sales suspension was lifted on 12 May 2011.55 As at September 2011, the mine was still not operating at full production on a sustained basis.56

Dawson-River-Enters-Cockatoo-Coal-Open-Pit-AfterRolleston Mine

The Rolleston mine experienced record rainfall: 250 millimetres fell in September 2010, with a further 366 millimetres falling in December 2010.57 Production was also affected by flooding of the Dawson highway and rail lines.58 The site was able to discharge excess water regularly during the wet season under its environmental authority,59 but did require two relaxations of it to prevent uncontrolled discharges from water storages.60 Xstrata Coal estimated a reduction in production forecast for 2011 by approximately 1.1 million tonnes as a result of the 2010/2011 wet season.61

Ensham Mine

Thanks to its levee banks, the Ensham mine did not suffer any flooding of its mine pits from the nearby Nogoa River or its tributaries during the 2010/2011 wet season.62 Heavy rainfall over the site itself increased the amount of surface water at the site.63 From 2 to 5 December 2010, the site received approximately 200 millimetres of rainfall. This flooded active mine pits and resulted in the cessation of mining activities.64 An authorisation to release water into the Nogoa River was sought and granted by DERM. The mine was, at November 2011, still holding water from the 2007/2008 and 2010/2011 wet seasons.65

Dawson Mine

By 28 December 2010, Anglo American advised DERM that heavy rainfall meant that it was no longer able to comply with the conditions of its environmental authority at Dawson mine relating to the management of mine affected water.69 Authorisations to release water were given in December, January and February. Following the 2010/2011 wet season, 4.5 gigalitres of water remained in a pit at Dawson North.70 The pit was to be mined in May 2011, but because of the large volume of water still inside it, mining had not commenced by November 2011.71

Moranbah North Mine

At Moranbah North, heavy rainfall occurred at Anglo American’s site in December 2010, with 80 millimetres falling the night before 20 December.66 The excess water being retained led to concerns about the safety of a dam on site; as a result, emergency authorisations were sought on 19 and 20 December to release water to prevent the dam from collapsing. DERM granted those authorisations.67 A longer term authorisation was granted on 24 December 2010, allowing continued releases from the water storage facilities.68

Moranbah Gas Project

By 13 December 2010, the water storage facilities at Arrow Energy’s Moranbah coal seam gas project were reaching capacity. Arrow Energy was concerned about the structural integrity of one of its dams.72 Between 13 and 14 December 2010, 2.6 megalitres of coal seam gas water was released in breach of Arrow’s environmental authority to prevent any failure of the dam.73 Further rainfall over the site necessitated the release of more water between 20 December 2010 and 6 January 2011: in total, another 34 megalitres of coal seam gas water was released in breach of the applicable environmental authority.74

Century Mine

At Century mine, the rainfall received during the 2010/2011 wet season was estimated to represent an event with an average recurrence interval of 150 years.75 Between 1 November 2010 and 1 April 2011, 1114.8 millimetres of rain fell in the area around the mine site.76 This figure represents more than double the annual average rainfall for the area.77 The heavy rainfall overwhelmed the water management system in place at the site.78

To maintain compliance with the terms of the site’s environmental authority, 1850 megalitres of mine-affected water was transferred to the open pit for interim storage.79 Storage of the excess water in an open pit resulted in significant operational and business risks for the operators of Century mine.80 Despite efforts to avoid it, including transferring water to pits and impairing production,81 one non-compliant discharge of contaminated water occurred on 15 March 2011.82

“One operator which did react was Anglo American; it undertook a pre-wet season review at its Capcoal mine which identified risks and recommended infrastructure upgrades, in consequence of which Anglo purchased additional pumping equipment.”

References

Source: Queensland Floods Commission of Inquiry 2012 – Final report. www.floodcommission.qld.gov.au

1: Transcript, Andrew Brier, 8 November 2011, Brisbane [p4766: line 2].
2: For example, see Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p7: para 32-34], Annexure SJR6; Transcript, Stuart Ritchie, 22 September 2011, Brisbane [p3073: line 26]; Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p2: para 8]; Exhibit 746, Statement of Pier Westerhuis, 26 September 2011 [p5: para 9(c)]; Exhibit 606, Statement of Mark Heaton, 6 September 2011 [p2: para 5].
3: For example, see Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p10: para 56(a)]; Exhibit 746, Statement of Pier Westerhuis, 26 September 2011 [p7: para 24].
4: State Budget 2010-2011 Mid Year Fiscal and Economic Review [p7].
5: Budget Paper 2 – Budget Strategy and Outlook 2011-2012 [p59].
6: Budget Paper 2 – Budget Strategy and Outlook 2011-2012 [p60].
7 Percentage calculated from $257.707 billion gross state product – Qld State Accounts for the June Quarter 2011 [p17].
10: Submission of the Queensland Resources Council, 11 March 2011; Submission of Rio Tinto Coal Australia Pty Ltd, 11 March 2011; Submission of Anglo American Metallurgical Coal Pty Ltd, 1 April 2011.
12: Submission of the State of Queensland, DERM-06 [p15-16]. 13: Submission of Rio Tinto Coal Australia Pty Ltd, 11 March 2011 [p3]; Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p2: para 10(c); p6: para 25, 27].
14: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p2: para 11].
15: Exhibit 1018, First Statement of Pier Westerhuis, 12 May 2011 [p1: para 3].
16 & 17: Submission of Anglo American Metallurgical Coal [p1].
18: Exhibit 924, Statement of Andrew Brier (Moranbah CSG), 27 September 2011 [p2: para 6, 7].
19: Exhibit 738, Statement of Robert Lawrence, 27 September 2011 [p2: para 4].
27: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p5: para 28]; Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p5: para 22]; Exhibit 746, Statement of Pier Westerhuis, 26 September 2011 [p6: para 15]; Transcript, Karl Spaleck, 5 October 2011, Brisbane [p3731: line 16]; Transcript, Stuart Ritchie, 22 November 2011, Brisbane [p3091: line 26]; Transcript, Robert Lawrence, 8 November 2011, Brisbane [p4790: line 1].
28: Transcript, Andrew Brier, 8 November 2011, Brisbane [p4770: line 15].
29: Transcript, Stuart Ritchie, 22 September 2011, Brisbane [p3091: line 19].
30: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p5: para 22]. 31: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p5: para 29-31].
32: Exhibit 606, Second Statement of Mark Heaton, 15 September 2011 [p1: para 1].
33: Exhibit 606, Second Statement of Mark Heaton, 15 September 2011 [p1: para 1].
34: Exhibit 746, Second Statement of Pier Westerhuis, 26 September 2011 [p5: para 12(a)].
35: Exhibit 748, Statement of Andrew Brier (Ensham Mine), 27 September 2011 [p2: para 9].
36: Exhibit 923, Statement of Graham Cordingley, 26 September 2011 [p4: para 17; p5: para 23].
37: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p6: para 42]; Exhibit 933, Statement of Andrew Brier (Rolleston), 27 September 2011 [p2: para 10].
38: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p5: para 34].
39: Transcript, Karl Spaleck, 5 October 2011, Brisbane [p3731: line 23]; Exhibit 606, Second Statement of Mark Heaton, 15 September 2011 [p1: para 1].
40: Correspondence from Commonwealth of Australia, 1 December 2011, Request for information- Bureau of Meteorology – Forecasting relevant to the mining industry [p2: para 2] 49: Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p7: para 33]. Water storages at mine sites are required to have a limited safety margin (or ‘freeboard’) that can be temporarily consumed if needed. This is generally how the storages are able to be above 100 per cent capacity. See Transcript, Stuart Ritchie, 22 September 2011, Brisbane [p3072: line 14].
50: Submission of Rio Tinto Coal Australia Pty Ltd [p3].
51: Submission of Rio Tinto Coal Australia Pty Ltd [p3]; Transcript, Stuart Ritchie, 22 September 2011, Brisbane [p3074: line 1].
52: Exhibit 934, Statement of Andrew Brier (Hail Creek), 27 September 2011 [p4: para 19].
53: Submission of Rio Tinto Coal Australia Pty Ltd [p3]; Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p11: para 64].
54: Submission of Rio Tinto Coal Australia Pty Ltd, 11 March 2011 [p3]. 55: Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p11: para 64]. 56: Exhibit 604, Statement of Stuart Ritchie, 14 September 2011 [p12: para 64].
57: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p8: para 57].
58: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p3: para 21-25].
59: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p8: para 60].
60: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p8: para 56].
61: Exhibit 938, Statement of Glenn Burlinson, 19 October 2011 [p3: para 20].
62: Exhibit 1018, First Statement of Pier Westerhuis, 12 May 2011 [p1: para 6].
63: Exhibit 1018, First Statement of Pier Westerhuis, 12 May 2011 [p1: para 6].
64: Exhibit 746, Second Statement of Pier Westerhuis, 26 September 2011 [p7: para 24].
65: Exhibit 941, Third Statement of Pier Westerhuis, 2 November 2011 [p7: para 19].
66: Exhibit 606, Second Statement of Mark Heaton, 15 September 2011 [p2: para 3].
67: See section 13.6.1 The Moranbah North Emergency Direction.
68: Exhibit 936, Statement of Andrew Brier (Moranbah North), 27 September 2011 [p5: para 25]; Annexure ASB-MN03-15.
69: Exhibit 937, Statement of Andrew Brier (Dawson Mine), 27 September 2011 [p3: para 14] 70: Exhibit 606, Statement of Mark Heaton, 6 September 2011 [p2: para 5].
71: Statement of Carl Grant, 1 November 2011 [p6: para 10].
72: Exhibit 924, Statement of Andrew Brier (Moranbah CSG), 27 September 2011 [p4: para 25].
73 Exhibit 924, Statement of Andrew Brier (Moranbah CSG), 27 September 2011 [p4: para 28].
74: Exhibit 924, Statement of Andrew Brier (Moranbah CSG), 27 September 2011 [p4: para 29]; Annexure ASB-MCSG02-09. 75: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p1: para 4].
76: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p1: para 3].
77: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p1: para 3].
78: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p2: para 6].
79: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p2: para 8].
80: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p3: para 9(c)(ii)].
81: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p2: para 8].
82: Exhibit 737, Statement of Karl Spaleck, 30 September 2011 [p2: para 7]; Exhibit 738, Statement of Robert Lawrence, 27

If you enjoyed this post, please consider leaving a comment or subscribing to our FREE eNewsletter to have future articles delivered directly to your inbox.

Related Products:




There are no comments

Add yours