【Mainland China】Implementation of GB 47946—2026, the Discharge Standard for Major Water Pollutants in the Danjiangkou Reservoir Area and Its Upstream Region: China's First Basin-Specific Water Pollutant Discharge Standard Takes Effect, Introducing "Custom

Introduction: China's first watershed-based water pollutant discharge control standard issued in the form of a national standard, the "Emission Control Standards for Major Water Pollutants (Total Antimony, Total Molybdenum, etc.) in the Danjiangkou Reservoir Area and Its Upstream (Trial)" (GB 47946—2026), has been implemented for new, expanded, and renovated projects since 2026 年 9 月 1 日. Targeting the core water source area of the South-to-North Water Diversion Middle Route Project, the standard implements watershed-customized control over characteristic pollutants such as total antimony and total molybdenum, marking China's water environment discharge regulation officially entering a new stage of refined governance characterized by "one zone, one policy; one water body, one standard."

I. The First Watershed-Based Emission Standard: From "Universal Limits" to "Tailored Solutions"

For a long time, China's industrial and municipal water pollutant discharge control has relied primarily on the "Integrated Wastewater Discharge Standard" and various industry-specific general standards, with local and watershed differences often compensated for through local standards or local "upgraded standards." The issuance of GB 47946—2026 marks the first time that "watershed" has been incorporated as an independent control unit into a national standard, representing a landmark innovation in China's water pollution control system.

• Tailored standard-setting — In response to the specific water body functions and water environmental capacity of the Danjiangkou Reservoir area and its upstream, generic limit values are no longer applied. Instead, targeted control requirements are established around the major risk pollutants in this watershed, highlighting a "problem-oriented, risk-oriented" approach;
• Two-phase transition — New enterprises are required to comply from 2026 年 9 月 1 日, while existing enterprises must comply from 2028 年 1 月 1 日, providing incumbent enterprises with approximately one and a half years for upgrading and retrofitting, reflecting a "steady progress with differentiated measures" approach;
• Full-chain coverage — The controlled subjects include not only point-source discharge units but also extend to non-point sources and emerging discharge sources, establishing a comprehensive framework covering "point sources to non-point sources, conventional to characteristic pollutants, and traditional to emerging discharge sources."

II. Why "Antimony and Molybdenum": Safeguarding the Security Bottom Line of the South-to-North Water Diversion "Large Water Reservoir"

The Danjiangkou Reservoir is the water source of the South-to-North Water Diversion Middle Route Project, serving hundreds of millions of people along its route, and its water quality safety is directly related to the national water security strategy. Non-ferrous metal, mineral mining, and smelting industries are distributed in the upstream areas and surrounding regions of the reservoir area. Once characteristic heavy metal pollutants such as total antimony and total molybdenum enter the water body, they are difficult to effectively remove through conventional treatment processes and pose risks of accumulation and health hazards, making them the "critical minority" in water source protection.

• Source prevention and control — The standard sets limit values for indicators such as total antimony and total molybdenum at the discharge end, compelling antimony- and molybdenum-related enterprises to upgrade their pretreatment processes and promoting source reduction and resource recovery;
• Monitoring constraints — Monitoring methods and supervision and management requirements are simultaneously clarified, providing a unified "yardstick" for environmental law enforcement and water quality early warning;
• Demonstration significance — As the first watershed-based national standard, its technical approach and control paradigm will provide a reference for the development of similar standards for key watersheds such as the Yangtze River and the Yellow River.

III. Resonance with the New National Standard System: 2026 Industry Signals in the "Standard Year"

Entering 2026 年 9 月, a batch of water pollutant discharge and prevention standards have taken effect concurrently, constituting the "upgrade season" for China's water environment standards: in addition to the watershed-based exploration of this standard, the "Technical Guidelines for the Formulation of Water Pollutant Discharge Standards for Centralized Wastewater Treatment Facilities in Industrial Parks" (HJ 945.4—2026), the "Discharge Standards for Water Pollutants from Textile Industry" (GB 4287—2026), and the "Discharge Standards for Water Pollutants in the Chishui River Basin" (GB 47945—2026) have also been implemented simultaneously.

• More refined regulation — From industry standards to watershed standards, from park guidelines to local classification, discharge control is moving from a "one-size-fits-all" approach toward refined management by "zone, industry, and source";
• Toxicity becoming a red line — Multiple new standards have generally introduced the concept of "integrated toxicity," with acute toxicity to zebrafish embryos becoming a new regulatory focus, and the concept that "meeting physicochemical standards does not equate to compliant wastewater" is gradually being put into practice;
• Genuine market release for upgrading — Stricter standards directly drive demand for standard-upgrading retrofits, advanced treatment, and online monitoring among water-related enterprises, creating definitive market space for wastewater treatment and resource recovery equipment.

IV. Impact on the Industry and Enterprises: From Compliance Pressure to Value Opportunities

For key antimony- and molybdenum-related enterprises located in the reservoir area and upstream regions, the 2028 年 1 月 "compliance deadline" means that they need to make advance arrangements in three aspects: process upgrading, monitoring capacity, and risk management. For environmental protection equipment and technical service enterprises, the implementation of watershed standards releases incremental opportunities in niche sectors such as advanced treatment, heavy metal removal, and smart monitoring.

For enterprises with long-term expertise in wastewater treatment and reclaimed water reuse, such "standard-driven" projects typically feature stronger policy rigidity, clearer discharge boundaries, and more sustainable operation and maintenance demands, making them a business direction worthy of focused attention. Under the trend of watershed-customized regulation, the comprehensive service capability of "understanding standards, ensuring compliance, and enabling resource recovery" is becoming the core competitiveness of water utilities facing the "15th Five-Year Plan" period.

About TIANYI TECH: TIANYI LIMITED has long been tracking global frontier developments in water environment governance and water resource recycling, with in-depth expertise in technical information and industrial services for wastewater treatment and reclaimed water reuse, committed to providing clients and industry partners with timely, professional industry insights and solution references.