2010-12-17_REVISION - C1981019 (104)

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RULE 2 PERMITS forks of Jubb Creek, respectively (Map l OB). During the pre - feasibility study, no surface water flow was observed at either location. To monitor surface water quality downstream of the proposed mine, Jubb Creek sampling location CJC, located at the confluence of East and West Jubb Creeks adjacent to valley fill monitoring well MJ- 95 -03, was used. Samples were collected from all three locations by KEC in 1996 and 1997. Surface Water Quantity — Baseline monitoring was conducted from December 2004 through May 2006 in the Collom Gulch, Little Collom Gulch, and Jubb Creek drainages. Field flow measurements were taken monthly at stream flow sampling locations, unless prevented by frozen or non - existent flow. Field flow measurements were attempted twice a year at springs and seeps. Based on the flow monitoring in 2004 through 2006, conditions in Little Collom Gulch, and within the upper Jubb Creek watershed were typical of intermittent or ephemeral streams, while the monitored sections of Collom Gulch can be characterized as intermittent or perennial. Baseline surface water monitoring data are presented in Tables 2.04.7 -46 and 2.04.7 -48. Streamflow hydrographs for representative surface water monitoring locations in these drainages are presented in figures 2.04.7 -40 to 2.04.7 -43. Surface water quality as measured by total dissolved solids (TDS) is also illustrated to show seasonal variability with respect to stream flows. Each drainage basin is discussed individually below. Collom Gulch — Colowyo measured flows at two locations in Collom Gulch (UCG and LCG) that ranged from 0.004 cfs to 3.5 cfs. Winter base flows ranged from 0.004 to 0.04 cfs. Maximum flows occurred in June, corresponding to snowmelt, spring runoff and/or precipitation events. Summer base flows (July through September) in Collom Gulch ranged from 0.01 to 0.03 cfs. Both Upper Collom Gulch and Lower Collom Gulch exhibit intermittent or perennial characteristics, with spring high flows the apparent result of snowmelt. Both are likely to be intermittent in dry years. Hydrographs for Collom Gulch sample locations can be found in Figures 2.04.7 -40 and 2.04.7 -41. From the hydrographs, it can also be seen that water quality, as represented by Total Dissolved Solids (TDS), varies seasonally in response to dilution from spring runoff. Little Collom Gulch — Little Collom Gulch was dry for all attempted monthly sampling events. Little Collom Gulch can be considered ephemeral at sampling point LLCG. Jubb Creek — Jubb Creek, at monitoring point CJC at the confluence of the East and West Forks, produced a maximum flow of 0.25 cfs in February 2005, and declined to 0.01 cfs in October and November, before freezing in December through January, and going dry in February 2006. The West Fork of Jubb Creek (monitoring point WFJC) produced flow from May through August, peaking in June at 0.30 cfs, and remaining dry throughout late summer, fall, and winter. Based on the available monitoring data, both streams can be characterized as intermittent, with spring high flows apparently the result of snowmelt. The East Fork of Jubb Creek was dry for all attempted monthly sampling events throughout the monitoring period, and can be characterized as ephemeral. Hydrographs for Jubb Creek sample locations can be found in Figures 2.04.7 -42 and 2.04.7 -43. From the hydrographs, it can also be seen that water quality, as represented by Total Dissolved Solids (TDS), varies seasonally in response to dilution from spring runoff. Springs and Seeps — A total of 33 seeps and springs fall within the Collom, Little Collom, or Jubb Creek drainages that will be affected by the proposed mining. Springs and seeps were monitored semi - annually, except when prevented by dry or frozen conditions. Those springs and seeps are identified in Table 2.04.7 -47, and monitoring results are summarized in Table 2.04.7 -49. Spring and seep monitoring locations are depicted on Map 10B. The monitoring data illustrates that springs individually contribute up to 0.30 cfs to stream flows during spring runoff, but often run dry or contribute far less than 0.01 cfs during summer and fall baseflow periods. Numerous springs identified during vegetation surveys proved Collom — Rule 2, Page 44 Revision Date: 1/23/09 Revision No.: PR -03