Monitoring and Control of the Nitrification Process Marine Park Water Reclamation Facility City of Vancouver, WA. Owen Boe1, Brad Stahlberger1, Xin Yang2. 1. US Filter EOS, MPWRF of Vancouver, WA.; 2. BioChem Technology, Inc., King of Prussia, PA. Abstract Removal of nitrogenous nutrient such as ammonia and nitrate from the wastewater stream is one primary goal of wastewater treatment plants in the protection of our inherited water environment. Without discharge permit limits on ammonia and nitrate, the operation team at Marine Park Water Reclamation Facility (MPWRF) of Vancouver, WA. has been voluntarily implementing the nitrification process and achieving total nitrification in the wastewater treatment process.In the past six months, the plant has been using the Biological Activity Meter (BAM-NT) for monitoring, evaluating and controlling the nitrification process. The on-line real time measured nitrification time (NT) by the BAM unit has been well correlated with the ammonia removal in the aeration basin. Diurnal variations in the ammonia loading and nitrification activity in the aeration basin are reflected in the NT measurement. A short period of ammonia breakthrough was observed in the aeration basin during the 24-hour sampling and measured by the BAM unit. Currently, the plant is trying to use the NT measurement to regulate the DO set-point control to achieve even better nitrification efficiency and save energy.