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Advanced Septic System Nitrogen Sensor Challenge

Advanced Septic System Nitrogen Sensor Challenge

EPA Region 1, EPA Region 2, New York State Department of Health, Massachusetts Department of Environmental Protection, The Nature Conservancy, Barnstable County, MA, and Suffolk County, NY

Residential septic system with nitrogen sensorThe EPA will assist in the development of a prototype nitrogen sensor that will be tested and deployed in 200 residential advanced septic systems.


Nitrogen discharges from conventional residential septic systems can cause critical water quality problems, such as toxic algal blooms that threaten public health. Advanced onsite technologies that can remove 50% or more nitrogen from residential wastewater are now available and in use. There is, however, no commercially available nitrogen sensor that can work in conjunction with advanced nitrogen removal septic systems. This project involves the development of  prototype nitrogen sensors that will be tested, evaluated and, among those that are successful, deployed in 200 residential advanced septic systems.  Real-time monitoring of the performance of nitrogen removal systems will demonstrate the long term effectiveness of advanced onsite wastewater treatment technology in reducing nitrogen discharges and improving water quality, and help accelerate their widespread deployment. 

Project leads: Maggie Theroux (, Kristina Heinemann ( and Ian Dombroski (