Problem 4 (25 pts): A factory has purchased the lower reservoir depicted in the problem above, and requires that the discharge rate to the reservoir be increased to 10Ls1. The utility is considering two options to meet the modified demand. The first option is to replace the old sewer pipe with structural steel pipe. The second option is to raise the elevation of the upper cistern to increase the pressure head. a) (10 pts.) What diameter structural steel pipe will be required to meet the discharge demand with the current storage tank height? Structural steel pipe is available in diameters of 0.05,0.10,0.15,0.20, or 0.25m b) (10 pts.) What elevation would the cistern tank need to be raised to in order to meet the modified demand with the existing sewer pipe? c) (5 pts.) The cost of structural steel pipe is $100+$2000 Diameter (m) per m of pipe. The price to raise the height of the water tower is $2500 per m elevation gain. Which is the most cost effective option to meet customer demand