Wambo Coal AEMR 2010-2011 - Peabody Energy

2010-2011 AEMRWollombi Brook recorded average EC values of731S/cm, 1076S/cm, 1243S/cm and 566S/cmat surface water monitoring sites SW01, SW02,SW03 and SW40 respectively. All annual averageEC concentrations for Wollombi Brook during the2010-2011 AEMR reporting period were lowercompared to the average EC concentrationsrecorded in the previous 2009-2010 AEMR. Allmonthly recorded EC values during 2010-2011 werewithin the SWMP surface water quality criteria, incontrast with the results from SW03 during the2009-2010 AEMR. During the last reporting periodthere were five occasions at SW05 where the ECcriteria was not achieved due to low flows in thebrook. However, the Wollombi Brook sustainedgood flows during this reporting period, resulting inlower EC concentrations.South Wambo Creek and Stony Creek recordedaverage EC values of 500S/cm, 554S/cm and325mg/L at surface water monitoring sites SW06,SW07 and SW08 respectively. All annual averageEC concentrations for South Wambo Creek andStony Creek during the 2010-2011 AEMR reportingperiod were lower when compared to the averageEC concentrations recorded in the previous 2009-2010 AEMR.All monthly recorded EC values during 2010-2011were within the SWMP surface water quality criteriafor SW08. Although the monthly EC criterion wasnot achieved on several occasions at SW06 andSW07. Both sites are upstream of WCPL miningoperation and therefore considered outside theinfluence of mining.Regular water samples were taken from SW05 andSW27 within North Wambo Creek during thereporting period and only one sample was taken atSW32 due to the creek being mostly dry at thislocation. EC results at SW05 did not meet the ECcriteria of 2140S/cm on several occasions. InAugust 2010 and September 2010 EC results of2,250S/cm and 2310S/cm were recordedrespectively. However the average ECconcentration at SW05 of 1390S/cm wasconsiderably lower than the previous year. Asexpected the EC criteria was achieved at SW05after good rainfall in November 2010 and June2011, where the measured EC was 281S/cm and405S/cm respectively.EC concentrations at SW39 exceeded the surfacewater quality criteria on two occasions. SW39 is tothe north west of the operations where grazingactivities occur on WCPL land under a private leasearrangement and therefore considered outside theinfluences from mining.Results from the WRD water monitoring programshow that EC in the Wollombi Brook achieved theEC criteria.As discussed above, surface water sites at LongfordCreek (SW43 and SW44) are adjacent to theGolden Highway and considered outside theinfluence of any WCPL activities. Additionallysurface water sites at Doctors Creek (SW46 andSW45) are immediately downstream from nonWCPL agricultural and mining activities, includingcattle grazing and coal stockpiling.Doctors Creek also provides for the passage ofmine water discharged from a neighbouring mine tothe Hunter River. During the reporting period therewere a number of visual confirmations that severaldischarges to Doctors Creek were beingundertaken. The high EC periodically recorded atDoctors Creek is consistent with these events.3.4.2.5 Oil and GreaseOil and grease results recorded during the reportingperiod concluded that oil and grease concentrationsin the surrounding waters were generally incompliance with the criteria set out in the WRDSWMP. Oil and grease results recorded during the2010-2011 reporting period are tabulated inAppendix 2C.3.4.2.6 Flow MonitoringIn consultation with NOW, WCPL completed aprogram to re-install all nine surface water flow sitesdestroyed during the June 2007 floods. Thereplacement program involved the installation ofhydrographic stations in North Wambo Creek, SouthWambo Creek and Stony Creek, the locations ofeach flow monitoring site are illustrated in Figure3.1NWC Flow monitor site FM1 – April 2009Page 51