The Setup: Your plant has been running smooth as silk. Turbidity is low, customers are happy, and your quarterly TTHM results have been well within limits. You're feeling pretty good about life. Then your latest sample results come back from the lab, and your TTHMs at the entry point to the distribution system (EDPS) are dancing dangerously close to the 80 ppb limit. Your supervisor mentions something about "enhanced coagulation" and suddenly everyone's looking at you like you should know what that means.