Assuming 65-percent pump efficiency for a slurry, the required horsepower to pump 4,053 gpm 

 to overcome 424 ft of head can be calculated as follows: 



Q H 



HP = SE2 ^^-a^ = 66g Hp 



3960(0.70) (3960)(0.65) 



For 8,800 ft of pipe and one pump operating at 668 HP, total head that must be overcome (or 

 required head that pump(s) must provide) is 424 ft. If placing two pumps in series, head 

 generated is additive (that is, two pumps generating 250 ft of head can together overcome 500 ft 

 of total system head). Therefore, using the above equation for 250 ft of head (in place of the 

 424) gives required HP = 394. Therefore, two pumps generating 394 HP (similar to that used at 

 Indian River Inlet) and able to overcome 250 ft can be used to accomplish the same pumping 

 requirement. The 500-ft total head provided by the two pumps provides for 76 ft of head as a 

 safety margin. However, certain labor and maintenance costs can be expected to be incurred 

 when operating two pumps versus operating one pump. Cost comparisons between purchasing 

 and operating two smaller pumps of the same size order as at Indian River Inlet versus one larger 

 pump should be examined to identify the optimum operating scenario. 



The Punaise alternatives will also require booster pump assistance for each scenario. The 

 first Punaise scenario requires boosting for the remaining 1,400 m (4,600 ft) of discharge length. 

 From the previous calculation using the GIW approach for head loss, 221 ft of loss will be 

 expected, thus requiring one booster pump. For the second scenario, boosting will be required 

 for the remaining 600 m (1,970 ft) of pipe discharge length causing 95 ft of head loss that must 

 be overcome with a booster. All costs shown under the Punaise scenario include the cost of this 

 additional booster pump. 



F4 Appendix F Booster Pump Worksheet 



