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Advanced Septic System Nitrogen Sensor Challenge Phase II: Prototype Testing


Conventional septic systems are not designed to remove nitrogen, which can lead to problems like excess nitrogen loading to waterways. This issue is especially important to coastal communities, where excess nitrogen causes eutrophication, hypoxia and toxic algal blooms leading to beach closures and other issues that negatively affect coastal communities. EPA estimates that over 2.6 million existing systems could be good candidates for advanced septic systems that treat the nitrogen due to their location in nitrogen-sensitive watersheds. Adding nitrogen sensors to these advanced septic systems will help manufacturers, homeowners, local and state governments know that these systems are performing as intended and protecting valuable coastal resources.

In January 2017, EPA partnered with The Nature Conservancy, USGS and others to launch Phase I of the Advanced Septic System Nitrogen Sensor Challenge.  Phase I challenged entrants to design a nitrogen sensor for use in advanced nitrogen-removal onsite wastewater treatment systems, also known as advanced septic systems, to monitor their long-term performance.  Phase I was open until mid-March 2017, and written proposals were judged by an external panel of experts.  EPA hosted the Sensor Showcase Day on June 29, 2017 and awarded the prizes. 

Phase II, Prototype Testing, was launched in December 2017 and is open to any sensor technology developer with a nitrogen sensor for advanced septic systems. EPA selected Battelle Memorial Institute (Battelle) to support the Prototype Testing Program by developing a Test/Quality Assurance Plan (T/QAP) and Verification Plan and overseeing the testing of the sensors. The T/QAP is based on the International Organization for Standardization Environmental Technology Verification (ETV) Standard - ISO 14034. Funding for the testing program is from the US EPA Office of Research and Development and the Office of Water/Wastewater Management.


The Challenge

Sensor testing will be conducted at the Massachusetts Alternative Septic System Test Center (MASSTC), a National Sanitation Foundation (NSF) certified test facility in Barnstable, Massachusetts in 2018-19. Under the new schedule, sensor developers will have the opportunity to test their sensor twice during the one-month tests, which will be held in October 2018 and January 2019. Each one-month test will include the one-week screening test during the first 7 days.

Developers whose sensors are judged to be capable of meeting minimum performance goals based on their one-week screening results will be invited to participate in an extensive 6-month field performance test. Battelle will verify the results of the field performance tests based on the VerifiGlobal Performance Verification Protocol and the requirements of the ISO 14034 ETV standard.

Informational Webinar 

An informational webinar was held on Monday, July 16, 2018. The Challenge is open to all who wish to enter! Page

Visit the posting here.

Timeline for Phase II

  • July 16, 2018 – Webinar on the T/QAP, the testing process and the application
  • August 31, 2018 – Deadline for submission of testing applications for the October 2018 one-month test.  Instructions to submit can be found on the cover page of the application.
  • October 1, 2018 – One-month test at MASSTC
  • December 7, 2018 - Deadline for submission of testing applications for the January 2019 one-month test.  Instructions to submit can be found on the cover page of the application. 
  • January 7, 2019 - One-month test at MASSTC
  • March 4, 2019- Notification of acceptance for the six-month test
  • Mid-May – Mid-November 2019 – Six-month field performance testing at MASSTC for the selected sensors
  • Late February 2020 – ISO ETV 14034 verification reports and statements completed

Sensor Performance Goals

Prize: Verification Report and 2020 Market Stimulation Opportunity

Following the release of the verification reports in early 2020, an external technical panel and The Nature Conservancy (TNC) will review the results. TNC and others are seeking funding for an order of 200 units, not to exceed a total cost of $300,000. The order would be presented in the summer of 2020 to the best performing sensor/s that completes the 6-month field performance test and meets or exceeds the performance goals.