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the 6700 bench has settled an average of 2.69 feet. <br />• Extra surve <br />s were cond <br />ted <br />the l <br />we <br />th <br />e b <br />he <br />fte <br />it <br />d <br />t <br />i <br />d <br />A <br /> y <br />r <br />enc <br />r <br />was <br />uc <br />on <br />o <br />re <br />s a <br />e <br />erm <br />ne <br />on <br />ugust <br /> 12, 1997 that the piezometer well was indicating a raised water level. No abnormalities were <br /> noted in these additional surveys. <br />~ 2. ~urv~ Monuments -Lateral Movement -Similar to settling, lateral movement remains <br /> stabilized. Lateral movement has stabilized at generally less than two feet overall and, with <br /> the exception of the 6700' level, in an easterly direction. <br /> 3. Borings and Seeos - No springs or seeps have been noted associated with the Fill. <br /> 4. Piezometer Well - On June 25, 1997 Colowyo tested [he Streeter piezometer well (the "north <br /> well") and found no abnormalities. On August 12, 1997 Colowyo tested the north well and <br /> was surprised to find a sound of cascading water and a first indication of water at a depth of <br /> 118 foot level. The depth to a consistent water level was at 175 feet. Colowyo immediately <br /> notified the Division by telephone on August l3, 1997 and followed with a letter dated <br /> August 14, 1997 describing the situation. A copy of the letter is included with the Inspection <br /> Reports found in Exhibit 6. A camera was lowered into the north well on September 9, 1997 <br /> and observed a casing perforation at 114.3 feet. Water was cascading into the north well at <br />• that location through a hole the size of a quarter. Apparently the perched water zone noted <br /> by CTLfThompson in 1981 located at the original 6800 level spoil dump during Fill <br /> construction (I I 1 foot depth) had caused the north well casing to fail and subsequently leak. <br /> The south well was also probed and the water level found at essentially the same depth as in <br /> 1981 suggesting that there was no additional flow of water into the zone during the previous <br /> 16 years. <br /> Colowyo has continued to monitor the situation by monitoring the water level fluctuation in <br /> both wells. The most recent monitoring data (January 9, 1998) shows the depth to water in <br /> the north well has continued to drop to 234.4 feet. At the same time the south well has also <br /> continued to drop to 129.7 feet. A copy of the well sampling summary can be found in <br /> Exhibit 6. <br /> The data suggests that I) since the south well is continuing to indicate that the perched water <br /> zone is dewatering, we anticipate that the flow into the north well may eventually stop; 2) the <br /> north well water depth continues to drop which means the perforations are functioning and <br /> allowing the inFlow to be routed into the rock underdrain; 3) the rock underdrain appears to <br /> be functioning properly; 4) assuming the perched water zone stops flowing into the north <br />• <br /> 4 <br />