If a concentration of E. coli exceeding 200 colonies per 100 mL of water is unsafe for swimming, tubing, or rafting, on which of the following collection days and at which of the 2 sites would it have been unsafe to swim, tube, or raft?

If a concentration of E coli exceeding 200 colonies per 100 mL of water is unsafe for swimming tubing or rafting on which of the following collection days and a class=