2021-04-14_PERMIT FILE - C1996084 (8)

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Rule 2: Permits • Lorencito Canyon Mine — Water Monitoring Plan The monitoring plan for the LCM is established to verify the projections of the Probable Hydrologic Consequences. To verify these projections, the plan designates sites that may be potentially impacted during the permit period, along with the water quality constituents that potentially may also be impacted. The sites will be monitored during the initial five -year and future permit terms. Locations of all wells, stations, springs and seeps, windmills and ponds are depicted on Map 2.04.7 -1. The mine is now in final reclamation with full Phase I bond release granted effective March 11, 2005. As predicted and demonstrated by baseline and subsequent monitoring, the impacts of mining on the Hydrologic Balance have been minim and monitoring frequency was reduced to semi -annual field data and annual analytical data for all alluvial well and surface water monitoring sites in 2007. The brevity of the active mining operation has minimi mine related impacts to water resources. No aquifers were intercepted as a result of mining; therefore, there have been no direct impacts to groundwater due to mining. Groundwater monitoring has detected changes in water quality outside the range determined by pre -mine water monitoring. But these impacts are likely to be due to the dewatering of groundwater aquifers resulting from Coal Bed Methane (CBM) wells and the establishment of an extensive road system to service and access these wells. Surface water drainage patterns were not impacted by mining operations. All run -off from areas disturbed by mining is diverted through sedimentation ponds. Discharge from these ponds is infrequent with no quantifiable impact on surface water quality. Based on the above factors, approval to terminate the water monitoring program was granted in 2009. Individual sites are addressed more specifically within the text to follow. Surface Water Surface water sites designated for monitoring are listed in Table 2.05.6 -9. Monitoring of site PC -1 was terminated in 2007 as mining related impacts never occurred within the area of influence affecting site PC -1. TABLE 2.05.6 -9 LORENCITO CANYON MINE SURFACE WATER MONITORING SITES Site Reason for Monitoring Status JC -1 Surface Mine Terminated LC -1 Surface Mine/Loadout Terminated LC -2 Surface Mine Terminated PC -1 Surface Mine Terminated PRGTY -1 Permit Area Terminated PRGTY -2 Permit Area Terminated I - I tmrel Page 2.05 -102 (Revised 10/27/09)