C153321 Feasibility Study - Laserfiche WebLink

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I I I 1 1 1 1 1 1 1 1 I 1 1 I 1 1 1 I washed rock to within 10 vertical feet of the top of the ground; 3/4" diameter washed rock to within 2 vertical feet and an impervious blanket the last 2 vertical feet. In- truding under the Dallas Creek will be two perforated 30" corrugated metal pipes buried 6 vertical feet deep and ex- tended into the 3/4" diameter washed rock. No filter needs to be used in this as the washed rock will act as the filter media. Evidence of this is demonstrated by the laboratory analysis ~aken approximately three-quarters (3/4) of a mile upstream by Loghill Village Subdivision which has a similar system. The main transmission line will be 6" diameter PVC Class 200 from the pump house to the storage tank. Approximately 6,300 linear feet of this line will be under pressure from the pump house while in use and static while not. Again, the line from the storage tank to the Town's.distribution system will be 8" diameter PVC. Drawbacks to Alternate II are as follows: The system will require two (2) submersible pumps of approximately 20 HP each pumping 150 gpm against a TDH of 335.6 with 148.7 psi static head (Note Exhibit XIII j. for pump alignment and structure); an intricate electrical system in the pump house for control over supply and demand; amortization of pumps over a 10 year period; additional operation and maintenance in the form of electricity and routine check-up of the plant. However, this may be offset by easy accessibility at all times of year and closeness to Town. 19