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Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2016 Annual Reclamation Report were repeated in 2016. In general, flow from some springs and seeps increased for a brief period after the adit plug installation and have declined to a steady state since the spring of 1997. Small variances noted since 1997, are believed to be attributable to a variety of conditions including precipitation, depth of snow pack,timing of snowmelt,and the potential for infiltration with respect to frozen ground. The"active"spring and seep locations are shown in Figure 4. Springs and seeps currently designated as"inactive" (no flow or seepage observed over the past five years) are not shown, but can be found on maps issued with past reports. Table 1 shows spring and seep data, including flow measurements, from 1995 to the present. Typically, the springs flow in the until the early summer months and then decrease rapidly to a point where there is little to no flow in the fall. 4.3.2 2015 Piezometer Completion In August 2015,two new piezometers(P-1land P-12)were installed within the underground mine workings in the South Mine area, as shown in Figure 3,to provide injection and/or extraction locations for the in-situ source treatability testing in the underground workings and to facilitate water level and water quality monitoring.The piezometers were designed in accordance with Colorado Office of the State Engineer Rules for Water Well Construction Rule 14 "Minimum Construction Standards for Monitoring and Observation Wells/Holes and Test Holes". A Colorado licensed well driller was used to advance boreholes and to conduct well installation, development, and sampling. HMC completed drilling pad construction prior to drilling as summarized in the TR-6 supporting information. Well construction logs are provided on the CD attached to 2015 report. 4.3.3 Groundwater Levels There are currently eight active piezometers installed in the area of the underground mine workings (P-4 through P-12).These piezometers are used to monitor water levels behind the adit plug and throughout the underground mine workings. Piezometers located within and/or in immediate hydraulic connection of the underground mine workings include P-4, P-5, P-11, and P-12,whereas P-7, P-8, P-9,and P-10 are located outside of the underground mine workings, with P-7 located immediately upgradient of the adit plug. Piezometer P-7 was installed as a replacement for P-6,which was monitored until about one year after plug grouting/construction. Piezometer P-8 lies just to the north of the underground mine workings and was also constructed to monitor bedrock water levels upgradient of the Pinnacle adit plug. This is also the closest piezometer to the Chester Fault Zone. P-8 was converted to a dual-purpose inclinometer in 1999 by installing inclinometer casing inside the piezometer casing. As described above, the newest of these piezometers, P-11 and P-12, were installed in 2015 as recirculation/monitoring wells for use in phosphate injections for uranium treatment as part of the LPL development(see Section 4.7). The locations of these piezometers are provided in Figure 4. Water levels in each of the eight piezometers fluctuates seasonally,with the highest levels observed in late May or early June, coinciding with snowmelt (Figure 5). Spring and summertime water levels vary from year to year due to the magnitude and timing of snowmelt and heavy summer precipitation events;however, water levels under low-flow or"baseflow" conditions can be used to assess long-term trends. Overall, the baseflow water levels indicate a groundwater gradient to the north/northwest. This gradient is steepest on the southern end of the North Pit, as demonstrated by the decrease in water levels moving from P-4/P-11 toward P-7, and further to P-8. The complex geology and hydrogeology at the mine site make it difficult to estimate water flow directions based on potentiometric surface alone. Groundwater is compartmentalized, as documented in early hydrogeology reports by Dr. David Snow(Leeds, Hill, and Jewett, Inc. 1979),which is a result of cross cutting faults, as well as the underground mine workings which add another level of compartmentalization. Regardless, the northward groundwater gradient is consistent with the hypothesis that groundwater present in the underground mine workings and Chester Fault moves northward and discharges into the North Pit Lake. Although comparison with P-10 also suggests a westward gradient, note that comparison of P-4/P-11 with P-9 further to the west suggests that this gradient is minimal following transition from the Granite/Precambrian east of the Chester Fault (P-10), into the Belden and Leadville Formations west of the fault(Figure 5). 20