C153349 Feasibility Study - Laserfiche WebLink

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I I I NOTES FOR TABLE-12: I (1) Static pressure created by Tank No. I (tank assumed to be empty), dynamic pressure from Well No. I pumping, surge pressure by Well No. 1 valve closure. I (2) Static pressure created by Tank No.2 (tank assumed to be empty), dynamic pressure from Well No. 4 pumping, surge pressure by Well No.4 valve closure or Wham booster pump station valve closure. I I (3). Static pressure created by Tank No.3, (tank assumed to be empty), dynamic pressure from Well ~. 2 pumping, surge pressure by Well No. 2 valve closure. I I Pressures at intermediate points in the mains can be approximated using the nearest given pressure in Table-12and adding 0.43 psi for each foot of drop in elevation or subtracting Q.43 psi for each foot of rise in elevation. I Due to the large differences in elevation in each zone, the pressures also vary over a wide range. Mains near the storage tanks have low pressures and mains at the lower end of each zone have excessively high pressures. High pressures contribute to water losses and broken lines. The information in Table-12was used to determine desirable locations for pressure reducing valves. However, pressure reducing valves can be added to the mains only if force mains are constructed which connect the wells directly to the storage tanks. I I I I 3. Pumping and Flow Rates - Typical flow rates in the distribution system depend on pump characteristics, elevation differences, and line friction losses. Table-13 lists the average pumping and flow rates between various points in. the system. The actual rates fluctuate somewhat based on water levels in stor- age tanks, ground-water levels in wells, and demands on the system. I I Transerring water under certain circumstances causes pressure increases that are considerably higher than the static pressures that a zone would normally I I I -4~