Problem: The operator of the biological phosphorus removal treatment plant is experiencing elevated amounts of phosphate (P) in the plant effluent. The luxury uptake process appears to be working optimally. The problem seems to be intermittent and occurs mostly on days the sludge dewatering equipment is operating. What is the most likely cause of the plant problem? O There is too much phosphorus uptake in the sludge dewatering equipment There is excess phosphate returning in the dewatering sidestream O The polymer dosage to the dewatering equipment is too high O An outside industry is discharging excess phosphorus into sewers the same day as dewatering occurs