Elucidating Sensor Application in Wastewater Treatment Plants and the Associated Environmental Impacts through Interview-Based Surveys in the New England Region of the United States

This innovative interview-based survey, conducted across 12 wastewater treatment plants (WWTPs) in the New England Region (US), aimed to determine the status and challenges of sensor technology applications in WWTPs. The primary objective of the study was to obtain stakeholder and users’ viewpoints regarding technology adoption for reducing energy consumption, enhancing treatment efficiency, and minimizing environmental impacts in this region. Previous studies in WWTPs mainly focused on crises and treatment issues, often overlooking operators’ perspectives and the integration of sensors and digitization in operations. Additionally, ineffective question design, misinterpretation of operator responses and lack of attention to region-specific needs have hindered meaningful insights. To address these knowledge gaps, this survey concentrated on the application and demand for diverse types of sensors in WWTPs located in the New England Region with a wide range of treatment capacities and processes. The uniqueness of this study lies in its concise, predetermined questions, the integration of quantitative and qualitative elements for deeper insights, assessment of reliability and correlation among survey responses, and a comparative analysis of region-specific demand. Survey reliability was supported by Fleiss’ Kappa (0.58) and Cronbach’s alpha (≥0.85), ensuring consistency across each thematic domain. The survey results revealed that 78% of the common process control sensors (e.g., flow meters, pressure) are currently used by the WWTPs interviewed, and 73% of these WWTPs identified frequent maintenance and sensor replacement as major barriers. While 47% of facilities recognized the importance of greenhouse gas (GHG) reduction, only 27% had implemented biogas or hazardous gas capture. Notably, 83% expressed interest in adopting GHG monitoring sensors (e.g., CO2, CH4, N2O) if they contribute to energy savings and process resilience. This study’s findings provide guidance for future sensor development, GHG emission reduction, energy saving, and treatment improvements in WWTPs.