Beijing Daily | Recycled water has become the "second water source" in Beijing! A record high of 1.277 billion cubic meters per year

March 22-28 is the 37th China Water Week, and the theme of this year's commemorative event in China is "Use water resources carefully, manage water resources strictly and meticulously".

As a mega city, water scarcity has always been the basic water situation in Beijing. Wastewater recycling and utilization is an effective way for Beijing to solve the problem of water resource shortage through meticulous planning. In 2023, the amount of recycled water used in Beijing has reached 1.277 billion cubic meters, reaching a historic high. Recycled water has become a stable and reliable "second water source" for Beijing.

How can recycled water become the "second water source" in Beijing?

81 recycled water plants meet the Class IV surface water standard for their effluent indicators

A jade belt river winds through Jingshui Middle Road in Liyuan Town, Tongzhou District. Although the small river is not wide, the water quality is good. Standing on the bank, you can see the floating water and grass at the bottom of the river. Not far along the river, clear incoming water flows continuously into the channel through huge drainage pipes, causing large white waves.

Not far from here is the Bishui Reclaimed Water Plant, which replenishes the river with recycled water generated by the plant's daily sewage treatment. According to Lv Jing, the process manager of Bishui Regenerated Water Plant, the current treatment capacity of Bishui Regenerated Water Plant is 180000 tons/day, undertaking 84% of the domestic sewage treatment tasks in the built-up area of Tongzhou District and serving more than 700000 people. The sewage treatment facilities of the water plant are all located underground. After a series of processes such as pre-treatment, biochemical treatment, and deep treatment, the sewage finally becomes high-quality recycled water. These reclaimed water can be used for landscape water, municipal greening, road sprinkling, cooling water of Sanhe Power Plant and ecological water supplement of Yudai River in Tongzhou District in Universal Studios, which can achieve 100% utilization and save about 65 million tons of tap water for Beijing every year.

Recycledwater is water that is purified and treated from the sewage pipeline network to meet specific water quality standards and can be recycled. "The earliest form of recycled water was actually a sewage treatment plant that adopted a deeper treatment method, which treated the sewage deeply and then put it into production and construction to achieve recycling," said Meng Yang, the relevant person in charge of the Sewage Treatment and Recycled Water Management Department of the Beijing Municipal Water Bureau. With the implementation of four "three-year pollution control actions", Beijing continues to promote the construction of recycled water plants and the upgrading and renovation of sewage treatment plants. Since 2012, all newly built recycled water plants and upgraded sewage treatment plants in the city have achieved the Class IV standard for surface water in one go (mainly applicable to general industrial water use areas and entertainment water use areas that are not directly in contact with humans), laying a solid foundation for the resource utilization of recycled water.

The water system landscape created by using recycled water within the Bishui Reclaimed Water Plant. Diagram provided by Bishui Reclaimed Water Plant

According to statistics, as of the end of 2023, a total of 81 large-scale (with a daily sewage treatment capacity of 10000 cubic meters or more) recycled water plants (sewage treatment plants) have been built in the city, with a total length of 2274 kilometers of recycled water pipelines. According to the three-year action plan for Beijing to comprehensively win the battle against urban and rural water environment governance (2023-2025), by 2025, the city will also build (expand) 10 recycled water plants and build 170 kilometers of recycled water pipelines.

The usage of recycled water accounts for over 30% of the total water consumption

Only by fully utilizing the water from the recycled water plant can we achieve efficient water conservation through careful planning. In recent years, our city has continued to promote the use of recycled water as a substitute for tap water in industrial production, urban sanitation, landscaping, service industry utilization, and ecological replenishment of rivers and lakes. While the overall urban water consumption remains unchanged, the amount of recycled water is gradually increasing.

In March, entering the campus of Communication University of China, vitality abounds everywhere.

A scenic water system on campus, Mingde Lake, with microwaves rippling on the lake surface, koi swimming freely in the water, willow branches blooming green and spring flowers blooming by the lake, making people feel relaxed and happy. On the bank of the embankment, a water pipe hidden under a fake stone extends underwater and is replenishing water into the lake.

"At the end of October last year, we completed the pipeline renovation and introduced recycled water into the campus. Now, the water sources for two water system landscapes on campus - Mingde Lake and Piano Lake - are both using recycled water." Yang Leilei, Deputy Director of the Logistics Support Department of Communication University of China, introduced that after the introduction of recycled water into the campus, it is mainly used for landscape water, green irrigation water, and other purposes. At present, the north campus of the school has completed the replacement of water sources. "This year, we plan to use summer vacation time to renovate the internal pipelines and facilities of the south campus, expand the use of recycled water to all campuses, and achieve the use of recycled water for green irrigation, landscape replenishment, toilet flushing, and other purposes," said Yang Leilei. By then, the campus is expected to save 120000 to 150000 tons of tap water annually.

The reporter learned from the Beijing Municipal Water Bureau that in the past year, the city has added 3 million square meters of recycled water for landscaping and greening, and the proportion of recycled water for environmental sanitation and greening has increased to 29.71%. The proportion of industrial recycled water has increased to 31.36%. The annual utilization of recycled water reached 1.277 billion cubic meters, reaching a historic high. At present, the proportion of recycled water usage in Beijing to the total water consumption has exceeded 30%, making it a stable and reliable "second water source".

Each recycled water plant will conduct joint debugging and control to ensure the supply of water sources

Regenerated water needs to be used well.

"Next, we will continue to optimize the planning and layout of renewable water use, expand the field and scale of renewable water use." Meng Yang said, on the one hand, based on the overall urban planning, we will further improve the laying of renewable water pipe lines in industrial construction clusters or areas where renewable water use is more frequent. At the same time, strengthen the pipeline connection between various recycled water plants, achieve joint debugging and control of recycled water sources among water plants, and ensure the supply of recycled water from multiple points and sources.

At present, the Municipal Water Affairs Bureau has organized Beijing Drainage Group to investigate the use of reclaimed water in the surrounding buildings, businesses, residential quarters and landscaping. In principle, the reclaimed water in the buildings, businesses, residential quarters and landscaping covered by the reclaimed water pipeline should be fully connected and used, and the allocation and utilization of reclaimed water should be continuously expanded. In addition, the Municipal Water Bureau will continue to increase the use of recycled water to supplement the ecological water of rivers and lakes, and enhance their ecological functions. Continuously strengthen supervision and management, enhance the diversification, cascading, and safe utilization of recycled water, and further leverage the comprehensive benefits of recycled water utilization.