An Exploration of the Impacts of Compulsory Source-Separated Policy in Improving Household Solid Waste-Sorting in Pilot Megacities, China: A Case Study of Nanjing

Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future.