Multi-Temporal Impact Assessment of Urban Wastewater

Abstract

Wastewater treatment plants (WWTPs) are responsible for approximately 1–2% of global greenhouse gas emissions, primarily releasing carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) during the treatment process. This environmental concern is particularly acute in urban areas, where dense populations generate large volumes of wastewater, often pushing treatment facilities to their capacity limits and reducing their efficiency in pollutant removal.This study demonstrates the enhanced applicability of Sentinel-2 (S2) satellite imagery, acquired during both summer and winter seasons, for mapping wastewater within urban WWTPs and monitoring their discharge into adjacent aquatic environments. The approach is based on customized algorithms adapted to process surface reflectance data, taking into account atmospheric effects. These methods have proven effective in identifying, mapping, and tracking the spatial extent and movement of wastewater, thereby offering a more accurate evaluation of its environmental impact.Such an approach is essential for assessing ecological risks and guiding sustainable water management, particularly in urban regions where WWTPs are critical infrastructure for safeguarding public health and achieving environmental sustainability aligned with the Sustainable Development Goals (SDGs).