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5. Since there was no quantitative information available on which to base an estimate of the amount of grout which would be required, the estimate of the amount of grout required was conservatively made. GTOut takes typically average 1 to 2 sacks per foot when grouting consolidated formations. The above cost estimate is based on an assumed grouting rate of 2 sacks per foot. However, the actual takes must be expected to vary considerably from this presumptive estimate. 6. Without the benefit ofgeoteclmical information, including field permeability tests, it is impossible to predict with any confidence the extent of seepage zones which will require grouting. You suggested that the length of dam along the crest that would require grouting would be about 100 feet. Because of the limited information available, we doubled that in our estimate for the sake of conservatism. Obviously, if the amount of grouting required is decreased, the costs will be reduced roughly proportionally. For example, if the length of grout curtain is only 100 feet, the costs would be cut approximately in half. 7. We anticipate that the grouting process will consist of the following: a. Drill primary grout holes spaced 20 feet apart using hollow stem auger methods in the embankment and coring in the sandstone. b. Pe1form permeability testing in the sandstone with packers. c. Pump grout in 5 to 10 foot stages at appropriate pressures using packers. d. If the stage takes significant grout, continue injecting low viscosity grout until it is estimated that the travel distance has reached at least 10 to 20 feet. Slowly increase the grout viscosity until grout takes stop. e. Drill and grout secondary holes intermediate between the primary holes if pervious zones are indicated by the primary hole grout takes. f. If there are indications that the surface dril1ing and grouting may not have intercepted the seepage aquifer permeable zones, drill and grout short holes along the grout curtain alignment from inside the outlet tunnel to close the grout curtain. 8. Because of the potential for wide variations in the actual fina\ scope of work as discussed above we have included a 25 percent contingency factor in the cost estimate. 9. Grouting should be performed during maximum reservoir drawdown for safety considerations and to minimize the potential for grout to be carried away by seepage flows. 10. Western Engineers has grouting capabilities. The above cost estimate is based on the costs we would expect to incur if we performed the scope of work described above.