The purpose of the current study is to reveal the reflections of the Köycegiz Wastewater Treatment Plant (WTP) field trip planned within the context of the unit "Domestic Waste and Recycling" and the activities carried out concerning this trip on middle school students in Turkey. This research was conducted based on the semi-mixed method using a single-group pretest-posttest quasi-experimental design. The quantified data were collected using open-ended questions about domestic waste and recycling, while the qualitative data were collected through semi-structured interviews. Twenty-seven middle school students (17 females, 10 males) participated in the study selected by convenience sampling method. According to the study's quantitative findings, the field trip to the wastewater treatment plant made the students realize the wastes produced at home, recyclable materials, the importance of recycling, and the contributions of wastewater treatment plants to the country's economy and nature. On the other hand, the quantitative findings indicate that this trip helped the students develop more eco-centric behaviors (Protection of biodiversity, Protection of nature, and Protection of resources, etc.). Moreover, the contributions made by the field trip structured within environmental education to the students could be gathered under the following headings: sustainability, personal, and cognitive.