Extraction Plan - Peabody Energy

Extraction Plan – North Wambo Underground Mine Longwalls 7 and 8Table 12Water Performance Measures, Performance Indicators and Contingency Measures for Longwalls 7 and 8Performance Measure Performance Indicator(s) Relevant Management and Contingency MeasuresNegligible impact toWollombi Brook.• The performance indicators will be considered to have beenexceeded if pumping of water from the North WamboUnderground Mine roadways requires regular pumping atrates higher than normal.• The performance indicators will be considered to have beenexceeded if the groundwater levels in alluvial bores exceedthe groundwater level criteria listed in Table 4 of the GWMP.• The performance indicators will be considered to have beenexceeded if the groundwater quality in alluvial bores exceedsthe groundwater quality criteria listed in Table 4 of theGWMP.• The performance indicators will be considered to have beenexceeded if the surface water quality in Wollombi Brookexceeds the surface water quality criteria listed in Table 11of the SWMP.• Consider whether the performance measure has beenexceeded based on subsidence, groundwater andsurface water monitoring data and hydrological and/orhydrogeological analysis.• If the performance measure has been exceeded,implement a Contingency Plan, which may include:- Implementation of stream flow loss remediationtechniques (e.g. injection grouting or installation ofa geomembrane).- Provision of offsets (i.e. retirement of an equivalentvolume of water licence).- Implementation of erosion and sediment controlmeasures and stabilisation techniques.- Additional monitoring (e.g. increase in monitoringfrequency).- Consideration of changes to longwall extractiongeometry in consultation with relevant regulatoryauthorities.EP/SMP LW7-8 Rev B December 2012 Page 34