Spontaneous Combustion Management Plan - Peabody Energy

WILPINJONGCOALPROJECTSPONTANEOUSCOMBUSTIONMANAGEMENT PLANMay 2006

Wilpinjong Coal Project – Spontaneous Combustion Management PlanWILPINJONG COAL PROJECTSPONTANEOUS COMBUSTION MANAGEMENT PLANJULY 2006Document No.: TCN0820-ENV-MP003/A0

Wilpinjong Coal Project – Spontaneous Combustion Management PlanTABLE OF CONTENTSSectionPage1 INTRODUCTION 21.1 OBJECTIVES AND SCOPE 22 DEFINITIONS 33 STATUTORY REQUIREMENTS 33.1 MINING OPERATIONS PLAN APPROVAL 33.2 WILPINJONG PROJECT APPROVAL 34 OBJECTIVES 35 ROLES & RESPONSIBILITIES 46 MANAGEMENT STRATEGIES 56.1 SPONTANEOUS COMBUSTION MECHANISM 56.2 MATERIAL CLASSIFICATIONS 66.2.1 Assessment of Carbonaceous Material 66.2.2 Identification of Inert Material 66.3 PREVENTION AND MANAGEMENT OF SPONTANEOUS COMBUSTION 66.3.1 Monitoring for Spontaneous Combustion 66.3.2 Preventing Spontaneous Combustion 76.3.3 Management of Spontaneous Combustion Outbreaks 87 REPORTING 98 AUDITING AND REVIEW 99 REFERENCES 9LIST OF TABLESTable 1DefinitionsLIST OF ATTACHMENTSAttachment 1Propensity for Spontaneous Combustion Laboratory ResultsTCN0820-ENV-MP003/A0i

Wilpinjong Coal Project – Spontaneous Combustion Management Plan1 INTRODUCTIONThe Wilpinjong Coal Project (the Project) is located approximately 40 kilometres (km) north-east ofMudgee near the village of Wollar in central New South Wales (NSW). The Project is owned byWilpinjong Coal Pty Limited (WCPL), a wholly owned subsidiary of Excel Coal Limited and is operatedby Thiess Pty Ltd.This Spontaneous Combustion Management Plan has been prepared in accordance with:• Condition 4 of the Mining Operation Plan approval issued by the Department of PrimaryIndustries- Mineral Resources (DPI-MR) on 7 March 2006, as follows:4. A Spontaneous Combustion Management Plan is to be presented to the Department’s satisfaction andimplemented prior to coal extraction taking place.• Schedule 3 Condition 22 (c) of the Project Approval 05-0021 issued by the Department ofPlanning (DoP) on 1 February 2006, as follows:22. The Proponent shall… (c) implement all practicable measures to minimise the off-site odour and fumeemissions generated by any spontaneous combustion at the project, to the satisfaction of the Director-General.This SCMP has been prepared to detail the management measures WCPL and Thiess will incorporateto ensure compliance with all licences and approvals and to prevent or reduce any adverse impacts tothe safety of all personnel and the environment.WCPL has total commitment to managing the safety of personnel and environmental impacts from theWilpinjong Coal Project. The practices to be undertaken to manage spontaneous combustion arecontained in this SCMP and will be revised regularly as required.1.1 OBJECTIVES AND SCOPEThe purpose of this SCMP is to describe the controls to be implemented for the management ofspontaneous combustion as part of the continued operations at the Project. This SCMP will recognisethat some coal seams have the propensity to spontaneously combust when exposed to air, willestablish measures to mitigate the potential for such an event to occur and will ensure that effectivemanagement plans are in place should such an event actually occur.This SCMP has been prepared to ensure that appropriate management measures are implementedduring the development and operation of the Project. Where there is any conflict between theprovisions of this SCMP and any Contractors’ obligations under their respective Contracts, includingthe various statutory requirements (i.e. licences, permits, Project Approval conditions and relevantlaws), the Contract and statutory requirements are to take precedence. In the case of any real orperceived ambiguity between elements of this SCMP and the above statutory requirements theContractor shall first gain clarification from WCPL prior to implementing that element of this SCMPover which the ambiguity is identified.The remainder of this SCMP is structured as follows:Section 2:Section 3:Section 4:Section 5:Section 6:Provides definitions of terminology used in the SCMP.Outlines statutory requirements of the SCMP.Outlines the objectives of the SCMP.Details the roles and responsibilities of personnel for implementing the SCMP.Provides details of the specific management strategies.TCN0820-ENV-MP003/A0 2

Wilpinjong Coal Project – Spontaneous Combustion Management PlanSection 7:Section 8:Describes the reporting requirements.Describes the mechanism of review of the SCMP.2 DEFINITIONSCarbonaceous materialInert materialsOxidationPitTable 1 – DefinitionsRock material with a carbon content sufficient to colour the rock dark grey to black andwhere a risk of self heating may be presentMaterial free of carbonaceous content and low chemical reactivity. Generally highlyweathered materials such as clays.Change in a substance due to a chemical reaction in the presence of oxygenRefers to the active mining areas directly related to the extraction of coal and wasteproducts3 STATUTORY REQUIREMENTSSpontaneous Combustion at the Project will be managed in accordance with:• The approval conditions of the Mining Operations Plan administered by the Department ofPrimary Industries – Mineral Resources, where the plan was prepared in accordance with MiningLease 1573 issued under the Mining Act 1992• Environmental Planning and Assessment Act, 1979 (EP&A Act) administered by the Departmentof Planning (DoP).3.1 MINING OPERATIONS PLAN APPROVALThe Mining Operations Plan Approval requires a Spontaneous Combustion Management Plan to bepresented to the Department of Primary Industries- Mineral Resources’ (DPI-MR) satisfaction andimplemented prior to coal mining taking place.3.2 WILPINJONG PROJECT APPROVALThe Wilpinjong Project Approval (05-0021) requires the implementation of all practicable measures tominimise the off-site odour and fume emissions generated by spontaneous combustion at the project.4 OBJECTIVESThe objectives of this SCMP are to:• Minimise the risk of spontaneous combustion occurring on the project;• Manage any occurrence of spontaneous combustion at the project effectively and efficiently; and• Minimise off-site impacts generated by spontaneous combustion;• Minimise the impacts generated by spontaneous combustion to any personnel on site.TCN0820-ENV-MP003/A0 3

Wilpinjong Coal Project – Spontaneous Combustion Management Plan5 ROLES & RESPONSIBILITIESSpecific responsibilities under this SCMP are as follows. Titles shown may vary from that shown onthe current organisation chart, particularly during the construction stage, and reflect positiondescriptions.WCPL General Manager• From time to time audit the implementation and operation of this plan.Mine Manager• Ensure that all persons that have responsibilities under this plan are aware of thoseresponsibilities.• Ensure resources are available to implement the requirements of this plan• Advise WCPL General Manager and the DPI-MR of any spontaneous combustion events.Mining Superintendent• Responsible for the implementation of this plan• Shall ensure the OCE/Mining Engineer conducts inspections competently• Consult with the OCE/Mining Engineer about appropriate management of spontaneouscombustion• Shall ensure key planning information is forwarded at appropriate times to the personnelresponsible for managing spontaneous combustion in the field• Shall be responsible for the coordination of remedial actions as required. Remedial ctions areidentified in Section 6 of this plan.• Manage any outbreaks or potential outbreaks as required• Will assist the Mine Manager and OCE/Mining Engineer in the collection of any relevantinformation associated with a spontaneous combustion outbreakOCE / Mining Engineer• Shall consider spontaneous combustion in the design of mining operations and spoilemplacement areas;• Shall ensure appropriate assessment of coal is conducted to identify possible risks ofspontaneous combustion occurring• Shall assist in the development of a strategy to manage spontaneous combustion for areasidentified as requiring attention in consultation with the Mining Superintendent andEnvironmental Advisor• Shall identify areas where spontaneous combustion is more likely to occur• Shall be responsible for considering spontaneous combustion in the planning of the finallandform• Shall ensure all materials are correctly disposed of and have responsibility of planning thetipping locations of carbonaceous materials• Shall conduct regular inspections of the coal seams and coal stockpiles to monitor for signs ofspontaneous combustion to be managed appropriately• Shall maintain all records on the age and location of stockpiles• Shall ensure all inert materials are correctly placed and not unduly wasted in areas where nospontaneous combustion exists• Will assist the Mine Manager and Mining Superintendent in the collection of any relevantinformation associated with a spontaneous combustion outbreakThiess Environmental AdvisorTCN0820-ENV-MP003/A0 4

Wilpinjong Coal Project – Spontaneous Combustion Management Plan• Consult with the Mining Superintendent and OCE/Mining Engineer about appropriatemanagement of spontaneous combustion• Ensure compliance with approval and statutory requirements for environmental managementof spontaneous combustion• Maintain a series of plans indicating areas where spontaneous combustion is known to haveoccurred.• Notify the Mine Manager, Mining Superintendent and OCE/Mining Engineer of communityissues associated with management of spontaneous combustionMine Surveyor• Shall verify that plans for final rehabilitation and spontaneous combustion managementcomply with details pertaining to the current Mining Operations Plan• Shall calculate the amount of inert materials mined each month by survey to enablereconciliation against usage for spontaneous combustion control• Shall measure and record the type and depth of cover of materials applied as inert capping onfinal landform surfaces• Maintain records associated with management of spontaneous combustionHSE Manager• Ensure management of spontaneous combustion is conducted in a safe and competentmanner• Ensure management of spontaneous combustion complies with all statutory safety obligationsAll Other Personnel• Shall notify the Mining Superintendent of any potential or actual outbreaks of spontaneouscombustion6 MANAGEMENT STRATEGIES6.1 SPONTANEOUS COMBUSTION MECHANISMSpontaneous combustion is the process of self heating of coal (carbonaceous material) by oxidation.In order for spontaneous combustion to occur the following three conditions must exist:• A fuel source in the form of coal (carbonaceous material);• Oxygen and moisture (water) must be present in the spoil spaces; and• Heat generated by oxidation processes in the coal (carbonaceous material).On exposure to air, in the presence of water to aid the exothermic reaction, coal undergoes acontinuous oxidising reaction. The hazard of spontaneous combustion exists when the rate of heatproduction exceeds the rate of cooling. The coal can then increase in temperature until combustiontakes place.The mining process begins the cycle by disturbing the coal (carbonaceous material). On exposure toair the coal commences oxidation. The oxidation reaction produces heat which can then potentiallycause spontaneous combustion if the self heating continues undisturbed. The actual spontaneouscombustion process is complex and subject to a number of influencing factors including gas content,oxygen supply, water content, particle size, secondary mineralization, geological structures andattendant leakage paths, and the rate of oxygen exposure of the coal to oxygen and convectioncooling.TCN0820-ENV-MP003/A0 5

Wilpinjong Coal Project – Spontaneous Combustion Management PlanUnshaped spoil dumps appear more susceptible to spontaneous combustion, since the batters havenot been reshaped. Based on spontaneous combustion occurring at other mines it has been foundthat reshaping batters allows the movement of air over the surface rather than penetrating through theunshaped steep batters into rock voids, and lowers the likelihood of spontaneous combustionoutbreaks.Additionally, based on previous spontaneous combustion of other coal mines it has been found thatareas that have experienced higher compaction (such as roads) exhibit less spontaneous combustionthan batter areas. This indicates that compaction is a method of controlling and managingspontaneous combustion.6.2 MATERIAL CLASSIFICATIONS6.2.1 Assessment of Carbonaceous MaterialA laboratory conducted an Acirl Adiabatic Self-Heating Test on a sample of coal. The results showedthat the average rate of self-heating from 40 o C to 70 o C (R 70 ) was 0 o C/hr. This laboratory result showsthat spontaneous combustion of the carbonaceous material is unlikely. The laboratory results areincluded in Attachment 1.However, based on experience of a nearby coal mine that is currently mining the same coal seam,spontaneous combustion is a likely occurrence. For this reason there will be ongoing assessments ofcarbonaceous materials on the Project. The assessments will include the ongoing collection ofcarbonaceous material samples to be analysed for its propensity to spontaneously combust. In-situtemperature probes may also be used on reject stockpiles and overburden dumps to analyse the longterm propensity of the carbonaceous material to spontaneously combust.6.2.2 Identification of Inert MaterialThe OCE/Mining Engineer and the Mining Superintendent will be responsible for identifying inertmaterials that are suitable for use as capping materials of oxidised/combustible material. Overburdenwill be examined by the Mining Superintendent and OCE/Mining Engineer when it is first removed.The material will then be classified as suitable or unsuitable inert material. A register of suitable inertmaterial will then be maintained by the Mine Surveyor and considered when building the finallandforms.6.3 PREVENTION AND MANAGEMENT OF SPONTANEOUS COMBUSTIONEfforts for managing spontaneous combustion will be focussed on prevention of outbreaks rather thanmanagement of outbreaks. The focus of spontaneous combustion management will be on reducingthe risk of an outbreak. All employees will be educated in the basic identification of smoke and heatassociated with spontaneous combustion and all employees will effectively be responsible fordetecting spontaneous combustion and reporting any visible signs of smoke to the MiningSuperintendent or OCE/Mining Engineer immediately.6.3.1 Monitoring for Spontaneous CombustionAll coal stockpiles will undergo regular visual inspections for the presence of spontaneous combustion.The OCE/Mining will conduct a visual inspection of the coal stockpiles for evidence of the presence ofspontaneous combustion every eight hours. The inspection will involve observing the stockpiles forany visible signs of smoke or any other obvious signs of heat production within the stockpiles.TCN0820-ENV-MP003/A0 6

Wilpinjong Coal Project – Spontaneous Combustion Management PlanThe high wall and the pit will be visually inspected once a day for evidence of spontaneouscombustion within the exposed coal seams. The OCE/Mining Engineer will observe the exposed coalseams for smoke or evidence of heat generation.Spoil dumps will be inspected by the OCE/Mining Engineer every day for visual evidence ofspontaneous combustion. The OCE/Mining and the Environmental Advisor will also conduct regularvisual inspections of the rehabilitated landforms for evidence of spontaneous combustion.Heat probes will be used to monitor long term coal stockpiles as required. The probes will be managedby the OCE/Mining Engineer. The monitoring stockpiles will be compacted to minimise the potential ofoxygen and moisture infiltration into the stockpiles and the results will be used to verify or predict thelikelihood of spontaneous combustion occurring in long term dumps.6.3.2 Preventing Spontaneous CombustionThe risk of spontaneous combustion occurring in the spoil and rejects emplacements and coalstockpiles will be quantified during the early stages of mining and coal preparation using anexperienced consulting body (eg Simtar). Appropriate control practices will be implemented to reducethe risk where necessary. The strategy will involve:• Inspection of Pit stratigraphy for likely spontaneous combustion potential horizons and suitableinert material• Designing sampling and testing programs• Providing guidelines for in-pit identification of high risk materials• Developing recommendations for capping depth and compaction requirements• Conducting annual review and inspection of the process and emplacement areas.A spoil balance of material of high spontaneous combustion propensity, and suitable inert material, willbe maintained and an appropriate dumping strategy implemented. This will be progressively reviewedbased on guidelines developed.Pending the development of the strategy, the Mining Superintendent or the OCE/Mining Engineer willinspect excavation areas for evidence of oxidation. Oxidised coal or carbonaceous shale will bedistributed toward the bottom of the overburden dump in such a manner as to minimise an outbreak ofspontaneous combustion. Oxidised coal will be placed in overburden dumps that are track rolled toform low angle batters and covered with inert material as soon as practicable. Low angle batters andcompacted oxidised coal has been shown to reduce airflow through the batters and accelerate the airover the top of the batters. The final approved landform is at or near current surface levels and doesnot include extensive exposed batters.Spoil identified as oxidised coal or carbonaceous shale will also be handled in a way that will maintaina larger particle size, with aggressive blasting avoided where practical. Smaller particle sizes increasethe surface area of the oxidised coal which leads to increased reactivity and a greater risk of aspontaneous combustion outbreak.Where carbonaceous material is placed in overburden dumps the Mining Engineer will ensure throughappropriate planning that there is sufficient inert material available to use as a capping material andthat this material is managed to maximise its benefits. This will minimise the risk of future spontaneouscombustion outbreaks in the final landforms. Inert material will be identified on the basis of propertiesthat inhibit ingress of air and moisture to the carbonaceous material. Carbonaceous material will alsobe confined to discrete cells confined by inert material so any outbreak cannot progress unchecked.TCN0820-ENV-MP003/A0 7

Wilpinjong Coal Project – Spontaneous Combustion Management PlanIn the pit, carbonaceous material will not be placed against the high wall unless shown to not pose arisk of future spontaneous combustion. Carbonaceous material in the low wall will be exposed for theminimum period practical, and where exposed will be visually monitored daily.Coal stockpiles will be managed to ensure that they are stockpiled for the minimum period possible.Records of the age of the coal stockpiles will be maintained by the OCE/Mining Engineer/CHPPmanager to ensure that the first coal produced is the first coal to leave the site, as reasonablypracticable. By reducing the age of the product coal stockpiles the potential for the heating rate toexceed the cooling rate is reduced. A Stockpile Management Procedure, including management forspontaneous combustion control, will be developed and implemented. This procedure will cover bothprevention and control practices.An objective of the operation of the CHPP is to minimise the amount of carbonaceous material, inparticular coal, in the coarse reject and tailings streams. Regular testing of both streams for carboncontent and spontaneous combustion propensity will be carried out as part of the coal qualityassurance program.Coarse reject from the Coal Preparation Plant (CHPP) will be placed below the rooting zone of therehabilitated landform within the waste rock/overburden, unless shown not to represent a spontaneouscombustion risk. A placement depth will be determined by expert advice and confirmed through aprocess of site monitoring. As a general rule overburden will be blended with the coarse reject at aratio of 2:1 to reduce the potential of spontaneous combustion. The waste material will then be trackrolled for compaction which will reduce the rate of oxygen and moisture infiltrating the reject. Thereject will then be capped with a layer of inert material. The capped material will be visually monitoredon a regular basis for signs of spontaneous combustion.Tailings will be placed in an approved emplacement area. The risk of spontaneous combustion onactive tailings emplacements is negligible but increases following decommissioning and desiccation.When the emplacement area is decommissioned the surface of the tailings will be compacted, if safeto do so, and capped with inert material to a nominal depth of 2m. The actual depth will be determinedbased on the properties of the tailings. The capped material will then be monitored on a regular basisfor signs of spontaneous combustion for the life of the Mine. The spontaneous combustion propensityof the tailings will not be clear until the CHPP is fully operational and has processed an adequatesample from the seams represented. Carbon content and spontaneous combustion propensity, alongwith other properties, will be identified as soon as practical and this information will be used to developthe decommissioning plan for the emplacement.Deep rooting vegetation will not be planted on areas capped to minimise the potential for breaching ofthe cap and thereby reducing the risk of spontaneous combustion.A rigorous inspection program of stockpiles and emplacement areas will be implemented as soon asspoil emplacements and coal stockpiles are developed. While this will initially be based on visual andodour assessment, targeting cool moist periods when signs will be most visible, it could includetemperature probes or heat sensing in the future. The need for a more sophisticated program will bedetermined on the basis of the detailed assessment program.6.3.3 Management of Spontaneous Combustion OutbreaksWhen smoke or other visible evidence of spontaneous combustion is identified in coal stockpiles (withthe exception of flames), the stockpiles will be reshaped using a fleet of dozers. During the process ofreshaping the stockpiles, heated coal will be exposed to air and cooled more readily. In addition thereshaping process may also aid in the track rolling the coal which will also reduce the risk of potentialspontaneous combustion outbreaks through the slight compaction. Shaped stockpiles have less of atendency to spontaneously combust as the penetration of oxygen into the stockpiles is reduced.TCN0820-ENV-MP003/A0 8

Wilpinjong Coal Project – Spontaneous Combustion Management PlanIn the overburden dumps, when smoke or other visible evidence of spontaneous combustion isidentified (with the exception of flames) the angle of the batters will be reduced and the batters trackrolled to accelerate airflow over the top of the compacted batters. Additionally, appropriate inertmaterial will be placed over the top of the oxidised coal.The use of water to prevent an outbreak of spontaneous combustion actually aides and acceleratesthe process of spontaneous combustion. Water will only be used on open flames. Where there is anoutbreak of spontaneous combustion and open flames are identified the area will be saturated in waterto put out the flames and cool the combustible material. The Emergency Response Procedure will beinitiated in the event of the identification of any open flames.7 REPORTINGSpontaneous combustion is a reportable incident to the DPI-MR. the Mine Manager will be responsiblefor reporting any outbreaks of spontaneous combustion to the DPI-MR and to WCPL as soon aspracticable. The Mining Superintendent and OCE/Mining Engineer will assist the Mine Manager in thecollection of any relevant information associated with the spontaneous combustion outbreak.Spontaneous combustion events will be reported in the Annual Environmental Management Report(AEMR) on an annual basis.8 AUDITING AND REVIEWThe SCMP is to be reviewed at least every three years or as otherwise directed by the Director-General of DPI-MR. The review process is to reflect changes in environmental legislation andguidelines, and changes in technology or operational procedures.9 REFERENCESThiess Pty Ltd (October 2005). Work Procedure 39 for Spontaneous Combustion – Collinsville CoalOperations Project.Hunter Valley Earthmoving Company Pty Ltd (February 2004). Liddell Open Cut SpontaneousCombustion Management Plan.TCN0820-ENV-MP003/A0 9

Wilpinjong Coal Project – Spontaneous Combustion Management PlanATTACHMENT 1PROPENSITY FOR SPONTANEOUS COMBUSTION LABORATORY RESULTSTCN0820-ENV-MP003/A0 10