Laserfiche WebLink
• 1. Survey Monuments -The survey information consists of quarterly surveys of the nine <br />monuments accompanied with corresponding diagrams to provide an analysis of the results. The <br />surveys indicate the fill has settled from .08 feet to 3.36 feet with a corresponding lateral movement <br />of .01 feet to 2.06 feet. The data suggests nothing more than the anticipated amount of settling and <br />consolidation of the Fill. <br />2. Piezometer Well -The piezometer well was established in June 1996. The well was drilled <br />through the spoil and underdrain and penetrated the underlying strata. A water level had been <br />detected at the 79-foot depth which corresponded to the level at which the drill penetrated <br />consolidated material underlying the rock underdrain. We interpreted the water level to be located <br />at the interface of the bottom of the rock drain and the underlying strata. During 1998 the water <br />level was detected at the 78 to 80.0 depth range which suggests there is no formation of a perched <br />water zone in the base of the fill. <br />3. No springs or seeps have been noted on the face of the Fill or associated with construction <br />of the Fill. Prior to construction of the rock underdrain, during clay and soil removal, a minor <br />perched zone of water was encountered adjacent to the canyon bottom. A lateral drain connected <br />to the main underdrain was constructed to ensure that the water is routed efficiently away from the <br />base of the Fill. Flow from the azea remains less than five gallons per minute and is routed to the <br />West Pit Pond . The lateral drain is located down gradient from the piezometer well and, as such, <br />has no apparent effect on the piezometer well. <br />• During the spring of 1998 it became appazent that the second drainage bench (neaz the 7050 level) <br />had settled in the azea that corresponds to the original valley bottom. As such the bench was too <br />flat and was not performing according to the design. The north end of the bench neaz the <br />confluence with the rock surface drain was lowered about 12 feet and tapered to the south to <br />reestablish the correct grade. The azea was graded, retopsoiled and seeded during the fall. During <br />1999 no further problems with the drainage bench were encountered and revegetation was taking <br />place. <br />In summary, during 1999 the construction of the West Pit fill proceeded according to the plan. In <br />addition, the monitoring suggests that the Fill is performing as designed. <br />i <br /> <br />