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108 provide graphical representations of water levels and selected water quality parameters recorded at site 29. <br />2006 Water quality parameters for these sites are typically within previously established ranges. <br />3.4 Saoil Spring Monitoring <br />Generally, groundwater migrates along bedding planes, faults, joints, or fracture zones. Given adequate head <br />pressure, if these zones of water migration intercept the surface, a spring or seep results. The TCC spoil spring <br />monitoring program was initiated in 1986 and is conducted annually. In accordance with the approved plan, the <br />annual mine wide survey is conducted during May, with springs measured for flow and field parameters. If a <br />spring is discharging at or above 35 gallons per minute, it is monitored for the next year in accordance with the <br />monitoring plan. Two spoil spring sites, 7 and Che 303 series (303-1 through 303-3), 2quire monitoring under <br />Exhibit 14-10. In addition to the spoil spring monitoring requirements, Spring 7 is monitored quarterly for field <br />parameters, and sampled on asemi-annual basis for water quality (if flowing). In 2006 site 7 did not flow. The <br />303 Spring series is monitored/sampled semi-annually for field parameters and water quality. <br />Tables 50 through 52 provide summaries of the 2005 Water Year data collected at each 303 series (303-1 through <br />303-3) spoils spring. Table SOa and Sla provide a period of record statistical summary of collected data at sites <br />303-1, and 303-2, respectively. Figure 109 provides a graphical representation of period of record field <br />conductivity for spoil spring 303-1. 2006 water quality parameters for series 303-1 are typically within <br />previously established ranges. <br />r~ <br />LJ <br />3.5 Natural Spring Monitoring <br />Two natural springs, SWl and SW2, located over previously mined areas in the Southwest Mining District <br />required semiannual monitoring during 2006. Prior [o mining, SW2 typically flowed throughout the year, while <br />S W 1 flows were sporadic. In recent years flows at SW2 have been minor, and in the case of S W 1, non-existent. <br />Minor flows was observed in SW2, in May of 2006. Analytical values were within historic limits. No flow was <br />observed in SW-1 in 2006. <br />In May 2006, a spring and seep survey was also conducted in the notthern mining district to identify potential <br />discharges to Fish Creek. No new or significant springs were identified in 2006. The northern mining district is <br />located within the Twentymile Park Syncline. The predominant lithologic unit nearest the surface and occupying <br />most of the basin is the Lewis Shale, which can be upwards of 700 feet thick. The lack of significant bedding <br />planes, faulting, or fracture zones in this area may account for the lack of springs in the central portion of this <br />basin. The few seeps observed in the basin may be the result from surface weathering of the Lewis Shale, which <br />may allow some accumulation of water beneath overburden. This may result in a short period of seepage <br />immediately following spring runoff. <br /> <br />11 <br />