The recycled water use policy in China: Evidence from 114 cities

The recycled water has been promoted throughout China to deal with municipal water pollution and water supply problems for a long time, however, its applications are not as expected by policy designers, suffering afflictions of unrealized targets, spare capacity, and low utilization ratio. Limited understanding of the influencing factors in recycled water utilization and their underlying mechanism makes managers difficult to figure out the crux of these problems so as to apply the remedies. In this study, the recycled water utilization status and the influencing factors in 114 cities of China are analyzed by adopting methods of Conditional Inference Tree, Random Forest, and Partial Dependence analysis. Results show that these cities can be divided into three groups by GDP and wastewater discharge, with decreased recycled water consumption in order. For the first group with high wastewater discharge, recycled water is promoted better from stringent recycled water utilization ratio target and large industrial demand, while remains in short supply from less production capacity; the production capacity expansion is necessary. In the second group with low pollution and high economic development, recycled water consumption is driven by the target, while is limited by less demand, inadequate production capacity and pipeline; the facility construction, pipeline network improvement, and diversified recycled water use are required. In the third group with low pollution and low economic development, recycled water consumption in one-third cities gears up by price advantage, while suffers under-supply from less investment and production capacity. Initiating more recycled water projects and increasing required investment should be prioritized in these cities. In the other two-thirds cities, the consumption is depressed by improper pricing policy, while remains under-demand from competitive disadvantage in municipal and environmental sectors. The demand-stimulating in industrial sector and pricing policy adjustment are the priority.