TEMPORAL ANALYSIS OF WASTE-SORTING BEHAVIORS OF UNIVERSITY STUDENTS: MEASURING THE IMPACT OF INTERVENTION EFFORTS

Cultivating effective waste-sorting habits will reduce waste stream contamination, extend the lifetimes of landfills, and nurture sustainably-minded communities. This study examines the impacts of various sustainability intervention campaigns on the lunchtime waste-sorting habits of students at a regional public liberal arts university in the Midwest. Multiple interventions, such as information sheets in napkin holders, waste bin modification and subsequent replacement, updating of waste-sorting instructions, waste-sorting demonstrations, and the display of informative banners, were implemented over the four-year period of 2016 to 2019. To investigate the impact of these interventions, waste audits were conducted at one set of landfill, recycling, and compost bins in the student center during two-hour lunch periods on three Tuesdays each fall semester between 2016 and 2019. Our results show that students’ waste-sorting habits did not significantly change over the 4-year period. Food was the largest contributor to the weight of lunchtime waste, and most food (by volume) was incorrectly placed in the landfill bin 64% (±8%), with 23% (±7%) going into the compost, and 13% (±2%) put in the recycling bin. Beyond wasting food and discarding most food waste in the landfill bin, two other critical issues are the disposal of mixed-waste “combos” (i.e., containers with different categories of waste), and too many well-known recyclables, such as Al cans and plastic bottles, going into the landfill bin (25% and 23%, respectively). The data indicate four barriers to effective waste sorting: 1) a lack of basic recycling and composting knowledge; 2) complicated products, including frequently changing product streams and the sale of mixed-waste items; 3) combining waste into one, convenient container at the table and then discarding the container without sorting into appropriate bins; and, 4) the need for a more comprehensive sustainability ethos across the campus. Based on these findings, we recommend that the campus coordinate with the food service provider to minimize mixed-waste products; and, encourage a sustainability ethos by more widely promoting sustainable actions via on-campus marketing campaigns and instituting a mandatory sustainability training activity for incoming first-year students.