Beyond essentials: Leveraging enhanced water refill stations to advance campus sustainability

Plastic beverage bottles are a significant contributor to marine plastic waste. Water refill stations (WRSs) and refillable water bottles are sustainable alternatives increasingly being adopted worldwide. This study explores how enhanced WRS functions and services can drive campus sustainability by examining university students' preferences, willingness to pay (WTP), and barriers to WRS adoption. Surveys (N = 322) were conducted at a Japanese university equipped with basic WRSs (providing room temperature and cold water). We analyzed preferences and WTP for enhanced WRS features using the best-worst scaling and contingent valuation method to estimate the WTP for each WRS feature. A behavioral barrier-based framework was employed to comprehensively identify barriers to adoption. We found that the enhanced WRSs save students money, contribute to campus sustainability, and are economically viable. 79.6 % were willing to pay for them for economic reasons. 99.2% of WRS users reported substituting their use of plastic-bottled beverages. However, 49.1% were non-WRS users, indicating a potential for broader adoption. Among the seven proposed enhancements, adding more WRSs was the highest priority, followed by bottle-cleaning features and hot water availability, aligning with the popularity of tea as the second most consumed beverage after water. The aggregated WTP and cost estimates suggest that enhanced WRSs with prioritized features are economically viable. Barriers to WRS adoption varied between WRS users and non-users, underscoring the need for complementary behavioral interventions and technical enhancements. Interventions, such as habit modification, may engage non-WRS users. • Enhanced water refill stations (WRSs) can promote sustainable campuses • Only 50.9% of the students used WRSs on campus, implying the need for improvement • Key desired features in WRSs include more WRSs, bottle cleaners, and hot water • Aggregated WTP estimates confirm the economic viability of enhanced WRSs • Complementary measures are critical for engaging non-RWB users