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indicates that the wells are relatively shallow. This is important because the wells aze completed in a local
<br />sandstone (presumed to be the Fish Creek sandstone) which overlies the massive Marine shale.
<br />• SPRINGS AND SEEPS
<br />A spring and seep survey was conducted by TCC in the Fish Creek drainage during May 1986. The survey
<br />identified all significant discharges to Fish Creek and delineated the specific stratigraphic interval of bedrock
<br />discharges where possible. The locations of these discharges' are shown• on Map 37, Fish Creek Ground Water
<br />Inflow Survey. Selected locations were measured for flow, temperature, specific conductance, percent salinity,
<br />and pH. The field data collected during the survey is shown on Table 60, Fish Creek Stream and Inflow
<br />Investigation. Flows were measured using a portable 4-inch cutthroat flume or a bucket and stopwatch. Field
<br />water quality was measured using standard instnuentation.
<br />The only significant spring identified during the survey issues from the Twentymile sandstone was 20-14, located
<br />in Section 11, TSN, R86W. This spring was eliminated from the overall Hydrologic Monitoring program in May,
<br />2003 (TR 03-42). '
<br />As described above, two springs (SWl & SW2) occur within the north half of Section 36, TSN, R87W. The
<br />existing monitoring data indicates the springs are low producers, typically discharging at a rate of 5 gpm or less.
<br />The springs appear to issue from the Fish Creek Sandstone. These',two springs were added to Twentymile Coa]
<br />Company's Hydrologic Monitoring Plan, and will be monitored on a quarterly basis for quantity and quality.
<br />Exhibit 14 has been modified [o include these springs.
<br />NMD and WMD (Panels 17-Right through 23-Right and 10-Left through 14-Left, PR03-06 and PR06-07)
<br />Supplemental Spring and Seen Survey
<br />• Supplemental spring and seep surveys of the TCC pemut area were conducted by TCC during May, in 2002 and
<br />2003. The surveys included an investigation of the NMD and WMD areas to identify potential discharges to Fish
<br />Creek. The locations of these discharges and other historical discharges can be found on Map 37A, 2003 Spring
<br />Survey. Discharge locations were measured for flow, temperature, pH and conductivity when adequate pooled
<br />water was available. The field data collected during the survey is, presented on Table 60.1, Northern Mining
<br />District Spring and Seep Survey. Flows were measured using. a portable cutthroat flume or a bucket and
<br />stopwatch. Field water quality was measwed using standard instrumentation.
<br />Generally, groundwater migrates along bedding planes, faults, joints or fracture zones. Given adequate head
<br />pressure and recharge, if these zones of water migration intercept the ground surface, springs or seeps develop.
<br />The NMD and WMD are located within the Twentymile Park synclinal basin. The dominant near-surface
<br />lithologic unit, which occupies most of the basin is the Lewis Shale, which can be upwazds of 700 feet thick. The
<br />lack of significant bedding planes, faulting, or fracture zones in this area, may account for a general lack of springs
<br />or seeps in the central basin. In general, as documented by Table 60.1, any springs or seeps identified by the spring
<br />and seep survey in the central basin are characterized by seasonal, low-volume flows, that may vary significantly
<br />from year to year dependent primarily on snowfall levels and the rate of spring snowmelt. Given the survey data
<br />and field observations, essentially all of the identified springs and seeps probably result from infiltration of
<br />snowmelt, and resulting shallow ground water flows along zones of lower permeability, to the point where these
<br />zones daylight on the sides of hills or in the numerous small ephemeral drainages in the area. Flows are typically
<br />of limited duration, drying-up within 30 to 60 days of snowmelt.
<br />Fish Creek Alluvial Wells
<br />Water quality is monitored at several alluvial wells located along Fish Creek. Alluvial wells going downstream
<br />include 006AY-1, 006-AZ-3, AVF-13, 006-AW-2 (to be abandoned in 2003), AVF-14, AVF-15, 008-AU-3 and
<br />• 008-AW-3. Figures 4j through 4q present water quality data (conductivity) for these sites, respectively. Tables 8m
<br />through 8t present a summary of period of record water quality data for these sites, respectively.
<br />PR06-07 2.04-25 11/07/06
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