Beijing’s ambitious targets to collect, treat and reuse water is prompted by the city’s water scarcity and water pollution problem. The city government has expanded its water reuse capacity through the “hybrid system,” considered to be robust, sustainable and efficient.
The hybrid system combines large-scale treatment infrastructure, collection and supply backbones with small-scale distributed infrastructure and local networks. Beijing operates a small number of large plants, mainly in the central urban area, and numerous smaller plants in the suburbs and rural areas of the municipality.
However, China’s approach to water reuse has its shortcomings. For instance, Beijing’s investments in treatment capacity surpass the investments in constructing distribution networks, which are important to manage reclaimed water more efficiently. Another problem is the low tariffs imposed on recycled water to stimulate demand leaving the government with a massive subsidy bill.
Lastly, standards lack consistency and completeness. At present, only the standards for water quality of reclaimed water is set, and none exist for the storage and distribution of reclaimed water.
For the analysis of this paper, plant-level data for more than 100 medium- and large-scale water reuse projects in Beijing currently operational or under development were collected. The research offers suggestions on how to improve Beijing’s hybrid water reuse system.
The findings show that Beijing’s water plants are prone to various interruptions stemming from inconsistent quantity and quality of infrastructure and a disparity in skills for the operator. If these issues are not addressed, many water plants may no longer be functional in the long run.
To further enhance the effectiveness of Beijing’s hybrid water reuse system, standards have to be harmonised, and quality monitoring has to be strengthened. Such measures will increase consumer confidence in the recycled water.
The financial sustainability of the system has to be secured as well. Presently, the large water plants are being financed by the municipal government, while the distributed plants are being financed by district governments. Due to financial constraints, district governments have turned to the private sector.
However, to provide the private investors with adequate returns, the municipal government has had to subsidise the private operators to compensate for the suppressed tariffs. Therefore, the participation of private firms appears to be an effective solution in the short run, but the long-run sustainability of this partnership is questionable.
Improving the financial sustainability of water reuse projects should be a priority. This could be achieved by raising the standard tariff for tap water, as well as the recycled water tariff.
Lastly, there is a need to increase the value of recycled water. China should aim to expand the proportion of reused water being utilised for productive purposes or to replace regular piped supplies. The government needs to improve the use and the production of reclaimed water. Such measures need to be dealt with some urgency given the severity of water scarcity in the municipality, aggravated by increasing population and economic growth.
Beijing’s water reuse system is undergoing a period of rapid development, not just regarding infrastructure but also regarding the institutional and regulatory environment. Once the planning, pricing and regulatory issues discussed are addressed, Beijing will be able to benefit from the full potential of water reuse.
This summary is based on the paper Wastewater reuse in Beijing: an evolving hybrid system.