Interventions for effective waste management and segregation: evidence from a randomised controlled trial in the Changzamtog district of Thimphu, Bhutan

Abstract

To address waste segregation challenges in the Changzamtog district of Thimphu, Bhutan, we conducted a randomised controlled trial (RCT) to test the effectiveness of interventions to improve the quality of household waste segregation. The RCT randomly assigned households a control group and one of two treatment groups. Treatment 1 saw households receive dedicated bins for collection, plus information on correct segregation practices, whilst treatment 2 added weekly feedback messages on top of treatment 1. The trial measured the impact of interventions by collecting waste over a period of three weeks. Both treatments significantly improved the proportion of correctly segregated dry waste, but had no effect on the proportion of correctly segregated wet waste. However, both treatments significantly reduced the amount of hazardous waste incorrectly disposed of. There also appeared to be a slight increase in hazardous waste disposal.