Chain-Dependent Barriers to Source-Based Management of Post-Ritual Materials in Urban Bali

Urban waste-governance programs rely on household source segregation, yet often assume that discards can be classified through stable technical categories. In culturally governed settings, post-use materials may also be classified through ritual status, propriety, edibility, and social obligation. This focused ethnography examined why source-based management of post-ritual offering materials, locally referred to as sisa upakara , remains difficult to sustain in urban Denpasar, Bali. Data were collected between January and March 2026 through 18 semi-structured interviews, four focus group discussions with 30 participants, six directed observation episodes totalling approximately 21 h, and document review across four anonymized urban sites. A hybrid deductive–inductive thematic analysis produced 2183 selectively coded segments. Five interdependent mechanisms explained practice formation and breakdown: post-ritual classification and legitimacy, domestic routinization, material-infrastructure fit, local-to-downstream verification, and system absorptive capacity. Management weakened when households could not distinguish edible remnants, ritually sensitive materials, and ordinary discards; when ceremonial peaks overloaded domestic routines; when fibrous, wet, bulky, or contaminated materials exceeded available infrastructure; and when downstream systems failed to preserve separated materials. The findings show that sisa upakara constitutes a hidden ritual-urban material sub-stream embedded within household waste. Culturally responsive waste governance requires alignment between classification guidance, household routines, material design, collection reliability, downstream verification, and decentralized processing capacity.