The world is facing an unprecedented water crossroads: by 2030, global water demand will exceed availability by 40%, and China, with 20% of the world’s population but barely 7% of its water resources, is at the epicenter of this tension. Beijing, one of the most populated megacities on the planet, depends on distant water transfers and suffers growing pressure on aquifers and urban rivers. In this context, every cubic meter of reclaimed water is not just an additional resource: it is a decisive factor for urban resilience, industrial competitiveness, and ecological security.
The Taihu Water Reuse Project, in Yizhuang New City, led by China State Construction Engineering Corporation (CSCEC) together with strategic partners, responds to this challenge in a visionary way. With a treatment capacity of 500,000 m³/day and a fully underground design, it is the largest water reclamation plant under construction in China, adopting state-of-the-art processes: AAO + MBR + ozone + advanced disinfection, capable of producing effluents that meet the strict Beijing Standard B (equivalent to Class IV surface water).
What was once an environmental liability, wastewater with a high industrial load, becomes a strategic resource. The project will supply more than 60,000 tons/year of high-quality recycled water to semiconductor, display, and smart vehicle industries, reduce freshwater withdrawals, restore the ecological flow of the Liangshui River, and allow the decommissioning of 12 scattered, inefficient plants. At the urban level, it will free more than 150 acres of land for social uses and generate more than 200 green jobs, consolidating Yizhuang as a hub of innovation and sustainability.
The project complies with the principles of additionality, traceability, and intentionality of VWBA 2.0, ensuring verifiable benefits (A-2: avoided consumption; A-6: safe onsite reuse) through physical monitoring with flow and quality sensors, and georeferenced digital traceability. In addition, it incorporates a net-zero carbon office building, becoming a global benchmark for integration between water infrastructure, climate neutrality, and resilient urbanism.
On an increasingly thirsty planet, this intervention is not a pilot: it is a new standard. It sets the course toward a Water Positive model, where every drop recovered multiplies economic, social, and environmental value.
The Yizhuang area, south of Beijing, faces three simultaneous and complex pressures: first, insufficient treatment capacity, with plants operating at the limit of their design and, during high-load episodes, causing emergency discharges that worsen the ecological deterioration of the Liangshui River; second, industrial pollution risks, since about 35% of wastewater originates from advanced manufacturing sectors (electronics, semiconductors, automotive) with the presence of heavy metals, solvents, and persistent organic compounds that are difficult to remove; and finally, the structural scarcity of water resources, given that reuse rates remain low, creating strong dependence on external transfers and compromising regional water security.
In the face of this situation, the technical and strategic opportunity lies in establishing a circular water system within the development zone itself, capable of supplying high-quality recycled water to high-tech industries, ensuring ecological flows that improve the resilience of the Liangshui River, and reducing pressure on aquifers and transfers. This project does not represent merely a one-off technological innovation but a structural change in governance and the very conception of urban water management.
The projected impact will be immediate and scalable: the new plant will contribute 80% of the treatment capacity of the area, generating tangible economic benefits (reduced production costs, lower dependence on imported water, energy optimization), reputational benefits (leadership in sustainability, regulatory compliance, and ESG accreditation), and environmental benefits (emission reduction, water and urban regeneration, biodiversity improvement). In the medium and long term, the consolidation of a water innovation hub in Yizhuang is expected, along with replication of the model in other Chinese and international cities facing similar challenges of accelerated urbanization, industrial pressure, and water stress. In this way, CSCEC and its strategic allies position themselves as catalysts of a water transition that is not only inevitable but also a decisive opportunity to redefine urban sustainability in the 21st century.
The project is based on an integrated and robust technological solution that combines conventional and advanced processes: physico-chemical pretreatment, AAO biological system, membrane bioreactors (MBR), advanced oxidation with ozone, and ultraviolet disinfection. This treatment train not only complies with Beijing Standard B (equivalent to Class IV surface water) but also ensures quality suitable for safe reuse in sensitive industrial processes, such as semiconductor production and the automotive industry.
The technology selection was based on several strategic criteria: (i) the ability to remove complex pollutants, including nutrients, heavy metals, and persistent organic compounds; (ii) operational reliability under variable load scenarios; (iii) energy efficiency and emissions reduction; and (iv) compatibility with climate and urban sustainability goals. Complementarily, an innovative sludge management system using low-temperature vacuum drying was incorporated, reducing final volume, minimizing odors, and harnessing by-products as a potential source of energy or raw material.
Quantifiable benefits include: recovery of more than 60,000 tons of high-quality water per year, reduction of more than 35% in local freshwater withdrawals, decrease of pollutant loads into the Liangshui River, and generation of operational savings through energy optimization and chemical reduction. Likewise, reclaimed water quality is verified under WQBA methodology parameters, ensuring that the positive impact on the basin is tangible and measurable.
Foreseen operational or environmental risks include membrane failures, sludge surpluses, or energy inefficiencies; all of these are mitigated through a preventive and predictive maintenance scheme, redundancy in critical processes, real-time digital monitoring, and contingency protocols that include automatic alarms, VWBA reporting, and external audits.
The project follows a phased and controlled approach, with detailed measurements, controls, technologies employed, and monitoring timelines in each stage:
The Taihu Water Reuse Project, in Yizhuang New City (Beijing), represents one of the most ambitious urban water infrastructure interventions in Asia. Led by CSCEC under a BOOT (Build-Own-Operate-Transfer) model, its design responds to a critical problem: the structural scarcity of water in a highly industrialized megacity, where demand exceeds availability and aquifers are under growing pressure. The underground plant, with a capacity of 500,000 m³/day, is the largest reuse facility under construction in China, with an AAO + MBR + ozone + UV treatment scheme that ensures Class IV effluent quality, suitable for high-precision industrial processes.
The relevance of this solution is based on three key transformations: (i) it converts complex industrial wastewater into high-quality water for semiconductor, automotive, and biotechnology industries, reducing freshwater withdrawals by more than 35%; (ii) it restores the ecological flow of the Liangshui River, mitigating decades of environmental deterioration and recovering biodiversity; and (iii) it reorganizes urban water infrastructure, enabling the decommissioning of 12 obsolete plants and freeing 150 acres of land for social and environmental uses. These actions translate into concrete benefits: reduced water and carbon footprints, creation of more than 200 green jobs, and provision of a reliable supply that ensures the competitiveness of one of China’s most important technology clusters.
From a strategic perspective, the project aligns with the Water Positive roadmap by meeting the principles of additionality, traceability, and intentionality defined in VWBA 2.0. The water benefit is quantified through methods A-2 (avoided consumption) and A-6 (safe onsite reuse), complemented by quality indicators under the WQBA framework. Physical traceability is guaranteed with flow sensors, multiparameter analyzers, and advanced spectrometry, while digital traceability is ensured with a georeferenced platform that integrates operational data, VWBA reports, and external audits.
The strategic value of this project transcends the technical: it inaugurates a new governance model in China based on public-private collaboration, reinforces CSCEC’s leadership in sustainable infrastructure, and projects a replicable innovation narrative at the global level. Its scalability potential is evident: any industrial zone under water stress can adopt this large-scale underground plant model, integrating reuse, energy efficiency, and ecological regeneration. Furthermore, the components of environmental education (SDG 4) and international partnerships (SDG 17) ensure that the project’s lessons transcend the borders of Yizhuang, generating knowledge, cooperation, and trust around resilient water solutions.
The final impact on the region’s water resources will be profound: each year, 60,000 tons of high-quality reclaimed water are added to the system, pollutant discharges decrease, the resilience of the Liangshui River improves, and Beijing’s water security is strengthened. At the same time, public health is reinforced by reducing exposure risks to pollutants, and the capital is positioned as a global benchmark in urban sustainability. This project is not just a plant: it is a statement of the future, an example of how cities can learn to live with water, regenerating its cycle and multiplying social, environmental, and economic benefits in a model fully aligned with the SDGs and the global Water Positive vision.
