Assessing Wastewater Emissions of Greenhouse Gases and Air Pollutants and Their Impacts

2019 Faculty Research Award

Award Period: 2019-2021

Princeton faculty Mark Zondlo and Z. Jason Ren will conduct a pilot field study to measure emissions of methane and nitrous oxide — both potent greenhouse gases — from wastewater treatment plants. They will then assess the broader environmental impacts of these emissions and explore potential mitigation strategies. Wastewater treatment accounts for 5% of global non-carbon dioxide greenhouse gas emissions, but these emissions are difficult to gauge due to chemical cycling, weather exposure, and the locations of treatment plants. This project will use an electric vehicle outfitted with air-quality monitoring equipment — known as the Princeton Atmospheric Chemistry Experiment mobile lab — to gather methane and nitrous oxide data from the areas surrounding 12 treatment plants in the Northeast of various capacities and treatment types. The plants will be sampled every three months to better understand the effect of seasons and weather on emissions. If successful, the project will be expanded to monitor and analyze plants nationwide and shed light on the wastewater industry’s impacts on the environment.

Educational Impact

Graduate and undergraduate students — including two PEI summer interns — in the Zondlo group will work with a postdoctoral researcher in the Ren group to collect and analyze field measurements. Local fieldwork will be integrated into a new graduate course, “Special Topics in Environmental Engineering: Environmental Field Design and Sampling” in Fall 2019. Research data will be used in the undergraduate course “Global Air Pollution” to develop lessons and laboratory experiments related to emission rates and dispersion.

Future Directions

The researchers plan to submit a proposal to the Alfred P. Sloan Foundation to quantify wastewater and agricultural waste emissions. Furthermore, the project will potentially provide the basis for a larger project proposal to be submitted to the National Science Foundation.

Participating Departments


Associate Professor of Civil and Environmental Engineering
Professor of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment

Graduate Students

  • Nathan Li, CEE
  • Daniel Moore, CEE

Undergraduate Students 

  • Sierra Castaneda, Class of 2020
  • Allen Dai, Class of 2022