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<br />the new fill to bey about 15 to 20 feet wide. As discussed later in the report, it is this <br />fill material that: is the focus of PSCO's concern from an engineering standpoint. <br />11. Surveys conducted in 1998-99 by personnel of PSCO indicate the pipe settled and <br />translated laterally. <br />12. Representatives of PSCO stated the area of standing water and marsh plants uphill <br />from the original embankment appears to have increased in size since placement <br />of the new embankment by Pathfinder in 1998-99. <br />13. Heavy truck tratfiic from Pathfinder's operations is reported to have substantially <br />increased in 1999-2000. <br />14. During the period between 1998-2000, the new fill embankment exhibited signs of <br />instability as evidenced by slumps, mudflows and springs. <br />15. In Pathfinder's 'technical Revision No. 3 to their Mining Permit, Pathfinder states <br />the new road is buik to San Miguel County Standards. We found two deficiencies <br />compared to County Standards which likely affect stability. The fill slopes are <br />steeperthan the required 2H:1V, and the embankment does not include drainage <br />such as a culvert where it crosses a natural drainage, such as the subject area of <br />concern. <br />Site Observations <br />On August 18, 2000 our Mr. Glater visited the Ames Hydro Plant to observe <br />sections of the fiberglass pipe in the storage yard (Fig. 6). The pipe was manufactured <br />by Ershigs and has an internal diameter of 30 inches, a wall thickness of 13/32 inch or <br />about 0.41 inch, consisting of 8 layers of fiberglass and resin. We obtained a design <br />manual from Ershigs. The current design manual contains reference to the pipe <br />configuration we observed. <br />We observed the embankment area about 4,100 feet south of the plant and made <br />measurements of the length, upstream and downstream slope inclination and height, <br />seepage quantities from a spring on the downstream slope, and obtained samples of the <br />typical materials exposed in the embankment. <br />The embankment is about 400 feet long, about 35 to 50 feet wide at the top, and <br />crosses a natural drainage course that has been modified by construction of Colorado <br />145. The uphill embankment height consistently averages about 13 feet above the natural <br />grade and has a slope of about 1.3:1 (Horizontal:Vertical). The uphill embankment slope <br />appears to have been constructed of sand and gravel and we believe it closely represents <br />the uphill slope of the original embankment, judging from the age of vegetation (aspens <br />PUBLIC SERVICE COMPANY OP COLORADO <br />AMEB HYDRO PENSTOCK <br />CTLIT 37,868 <br />