3. A step-dose tracer test was conducted on the clear well of a water treatment plant. A constant dosage of 2.0mg/L was added at the inlet starting at time zero, and the residual concentrations in the outflow were measured as shown. a. Calculate the C/Covalues. val b. Plot C/C0 versust. c. Determine t10. 4. What are the requirements specified by the EPA Surface Water Treatment Rule for: a. The inactivation of Giardia and viruses? b. The turbidity of the filtered water? c. Chlorine residual in the water entering the distribution system