5. (20 points) A groundwater at 5C and pH 7 is used as a source for drinking water. The water receives no treatment other than disinfection by free chlorine at a concentration of 2 mg/L. Assume that the disinfection process must be capable of inactivating 99.9% Giardia cysts. (a) Using the EPA Ct tables in Appendix D of our textbook, determine the required values for Ct and to. You can assume the free chlorine stays constant at 2 mg/L. (b) For a design flow rate of 0.5 m/s, determine the length, width and sidewater depth needed (increments of 0.7 m) for a longitudinal-serpentine chlorine contact chamber. The sidewater depth will be three times the width of the chamber. For the length-to- width ratio, assume that the design criterion will be tid/te=0.8 and that Figure 13-12 in our textbook applies. Again, assume the free chlorine stays constant at 2 mg/L. (c) If the land available to build the contact chamber is 40 m by 15 m, provide a simple sketch showing the chamber from above (i.c., plan view). In your sketch, use arrows to show the direction of water flow and include appropriate devices to minimize dead spots and flow separation