Wambo Coal AEMR 2010-2011 - Peabody Energy

2010-2011 AEMRGain advice on most suitable trimming height forhedges to south of Main Homestead building.4. Main Homestead building:Assess stability of pylons on southern and northernverandas and requirement for additional propping tomaintain water shedding function of gutteringsystem and arrange for temporary proppingsupports.5. Main building:Assess water shedding function of existingguttering/roofing to identify areas forrepair/improvement, including repairs to existingguttering/roofing and the installation of temporarydown pipes.Continued routine maintenance and conservationworks on the WHC are planned for the nextreporting period. The revision of the CMP for theWHC is a major activity planned for the upcomingreporting year.Blast Vibration StudyWambo currently monitors and reports on open cutblasting ground vibration, and potential impacts onthe WHC. Ground vibration is currently monitoredand assessed based on peak particle velocity (ppv),measured in mm per second.In response to concerns expressed about theaccuracy of assessing blast vibration impacts basedonly on ppv, WCPL engaged a specialist engineer(Bill Jordan & Associates) to investigate whetherblast ground wave frequency, as well as ppv, is amore accurate indicator of potential vibrationimpacts. It has been previously been shown thatmovement of the building or its parts can be greatlyamplified compared with the blast wave if resonantfrequencies are excited in the building.The results of this study will allow a betterappreciation of the risks posed to the WamboHomestead buildings from blast ground vibration,and lead to more accurate setting of blast limits, andblast design, which will take the resultingfrequencies into account.The study was ongoing at the completion of thereporting period. Outcomes of the study will beincorporated into the Wambo Blast MonitoringProgram, and reported in the next AEMR.Blast AssessmentWCPL forwards all blast monitoring results for shotsfired within 2km of WHC to an independent engineerfor assessment. In April 2011, two shots in thenearby Homestead pit resulted in ground vibrationresults of 13.6 & 11.9 mm/s at the HomesteadMonitor. As well as the site based investigation, anindependent engineer was engaged to conduct astructural inspection of the Homestead to identifyany impacts from these blasts. The inspectionidentified superficial cracking in the New Houseceiling plaster, but no impacts to the structuralintegrity of the WHC buildings. A copy of this reportwas provided to DOPI.3.14 Spontaneous Combustion3.14.1 UndergroundThere were no spontaneous combustion incidents atthe Underground during the reporting period.Inspections for spontaneous combustion form partof the Underground inspection system. WCPL willcontinue to monitor for signs of spontaneouscombustion in the next reporting period.The Underground mine atmosphere is monitoredcontinuously in the main fan return. Monitoringresults and trends are displayed in the control room.Any abnormal readings trigger an audible and visualalarm. All monitoring equipment is tested andcalibrated regularly.3.14.2 Open CutAs reported in previous AEMR’s, spontaneouscombustion (spon comb activity within the Open Cutoperations is limited to one location. The spon combis located on the north western side of the HunterPit. This incident is considered minor and is beingmonitored by WCPL operations. Inspections forspontaneous combustion form part of the Open Cutinspection program.3.14.3 CHPPThere were no spontaneous combustion incidents atthe CHPP during the reporting period. Inspectionsfor spontaneous combustion form part of the CHPPinspection program.3.15 Bushfire Management3.15.1 Environmental ManagementThe Bushfire Management Plan (BFMP) wasoriginally approved by the NSW Rural Fire Service(NSWRFS) and SSC in 2005. This planincorporates both an identification of likely bushfirePage 73