Investigation Using Advanced On-Line Instrumentation of Industrial Loading on a Wastewater Treatment Plant in Glen Cove, New York Lance K. Mason * , Dan Ryan * , John Watts ** , Marc Bingley *** , Andrew Shaw, John Upton *** * Severn Trent Services ** Capital Controls Limited *** Process Technology, Severn Trent Water Limited ABSTRACT The regulatory requirements at the wastewater treatment plant at the City of Glen Cove, New York will soon include a standard for total nitrogen in the effluent of 9.0 mg/L. There is a need to make the necessary arrangements to ensure compliance with the new discharge permit such as a need for a conversion to a BNR process. To achieve this standard the wastewater plant needed to be researched not only in terms of biochemical oxygen demand and ammonia-nitrogen removal, but also in terms of the changes that needed to be made to accomplish denitrification. With this in mind, a research project using advanced online monitoring techniques was initiated and the results would be compared to conventional laboratory methods and calculations, as well as mathematical modeling to ensure the future changes to the facility would maintain compliance. The study results revealed concerns pertaining to the lack of a readily biodegradable carbon source for denitrification in the influent. Respirometric results demonstrated episodes of nitrification inhibition related to an industrial source. The conclusions and plant characterizations would not have been possible with traditional laboratory sampling and analysis. KEYWORDS respirometer, denitrification, nitrification, nitrate, BNR, online BACKGROUND The City of Glen Cove, New York Wastewater Plant is located in the Northeast portion of Long Island and serves a population of approximately 29,000. It is proposed that the Long Island Sound area will soon have limits placed on total nitrogen of 9 mg/L. The permitted flow for the facility is 8.0 MGD with about 40% of the flow being contributed by surrounding industry. The facility is a plug flow design with eight parallel rectangular lanes (only six are in operation), which are fed from the primary clarifier. The aeration effluent flows to secondary clarification and then is disinfected with chlorine. The RAS to influent flow ratio is approximately 1:1 during the day and during low flow periods at night and early in the morning, the ratio can be as different as 2:1 respectively. WEFTEC 2000 Copyright (c) 2000 Water Environment Federation. All Rights Reserved.