Many cities in Indonesia are under pressure to reduce solid waste and dispose of it properly. In response to this pressure, the Japan International Cooperation Agency and the Indonesian Government have implemented a solid waste separation and collection project to reduce solid waste in the target area (810 households) of Balikpapan City. We used a cluster randomised controlled trial method to measure the impact of awareness-raising activities that were introduced by the project on residents' organic solid waste separation behaviour. The level of properly separated organic solid waste increased by 6.0% in areas that conducted awareness-raising activities. Meanwhile, the level decreased by 3.6% in areas that did not conduct similar activities. Therefore, in relative comparison, awareness-raising increased the level by 9.6%. A comparison among small communities in the target area confirmed that awareness-raising activities had a significant impact on organic solid waste separation. High frequencies of monitoring at waste stations and door-to-door visits by community members had a positive impact on organic solid waste separation. A correlation between the proximity of environmental volunteers' houses to waste stations and a high level of separation was also confirmed. The awareness-raising activities introduced by the project led to a significant increase in the separation of organic solid waste.
Keywords: Balikpapan City; Indonesia; Waste separation; awareness-raising activities; cluster randomised controlled trial; waste station.