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Gate Stem and Stage Marker Anchor Bolts. Anchor bolts for the gate stem <br /> assembly and stage marker were misplaced during project construction. The contractor <br /> obtained and installed stainless steel replacement bolts, rather than originally specified <br /> galvanized steel. Bent anchor bolts were installed for the stage marker, similar to the gate <br /> stem assembly bolts, rather than straight bolts with wedged shims. <br /> Outlet Trench Backfill Material. The new outlet conduit, including upper and lower <br />• concrete cradles, was constructed in a trench approximately five feet wide and four to six <br /> feet deep. The contractor requested permission to place a flow fill mixture as backfill to <br /> the top of the trench, rather than the compacted embankment fill. A modified flow fill with <br /> a cement content of 3 sacks (282 pounds) per cubic yard was proposed and approved by <br /> the Office of the State Engineer. Placement of flow fill in the trench resulted in good <br /> contact between the existing embankment and the trench backfill without use of <br /> compaction equipment which would have been required with soil fill. <br /> Filter Blanket Installation. Subsequent to resuming work after the winter shutdown, <br /> a persistently wet and seeping area of the original embankment backfill was apparent at <br /> the west end, on the north side of the conduit. Following recommendations provided by <br /> Alan Claybourn of Kumar and Associates, the contractor removed all wet material which <br /> had been disturbed by equipment traffic and placed a one foot thick filter blanket <br /> consisting of Type I filter sand in the area of concern. The filter blanket was tied into the <br /> filter sand backfill around the slotted drain pipes behind the outlet headwall to provide a <br /> flow path exiting the dam. Sheet 2 of the As-Constructed drawings shows the <br /> approximate location of the filter blanket. <br /> Bypass Conduit Abandonment. Close examination of the existing 24-inch <br /> corrugated metal bypass conduit, previously used to convey water from the interceptor <br /> canal through the dam, showed that the conduit was in good condition and adequate for <br /> grouting with the exception of an obstruction in the pipe. The obstruction was located at <br /> an elbow approximately 125 feet from the downstream end, and required removal of the <br /> elbow and all conduit below the elbow. The filter diaphragm was subsequently placed <br /> 5 <br />