[Mainland China] GB 47946—2026 Implementation: China's First National Standard-Form Basin-Type Water Pollutant Emission Control Standard, Safeguarding the Water Source Area of the South-to-North Water Diversion Middle Route

Key Highlights: GB 47946—2026 "Emission Control Standard for Major Water Pollutants (Total Antimony, Total Molybdenum, etc.) in the Danjiangkou Reservoir Area and Upstream (Trial)" has been implemented since 2026年9月1日, with new enterprises required to comply immediately and existing enterprises transitioning until 2028年1月1日. This is China's first watershed-type water pollutant emission control standard issued in the form of a national standard, setting emission limits for characteristic pollutants such as total antimony and total molybdenum for the first time for the water source area of the Middle Route of the South-to-North Water Diversion Project, and establishing a comprehensive control framework covering "point sources—non-point sources, conventional—characteristic pollutants, traditional—new emission sources."

I. From "Industry-General" to "One River, One Standard"

For a long time, China's water pollutant emission standard system has been dominated by industry-specific standards (such as textiles, electroplating, pharmaceuticals) and comprehensive standards (such as the "Integrated Wastewater Discharge Standard" GB 8978). This system addressed the common issue of "what to discharge and how much," but struggled to respond to a reality: the same compliant discharge occurring in a large river with abundant flow versus upstream of a reservoir area that supplies drinking water for hundreds of millions of people produces completely different environmental consequences.

The issuance of GB 47946—2026 marks a structural supplement to the standard system. It no longer divides by industry, but by watershed unit—taking the Danjiangkou Reservoir Area and upstream as the control boundary, specifying the emission control requirements, monitoring requirements, and supervision and management requirements for major water pollutants within the region. This is the first issuance of its kind.

The significance of this "watershed-type national standard" lies in the fact that it recognizes that different water bodies have different environmental capacities and protection needs, allowing differentiated management and control to be implemented within the same territory. Alongside it, GB 47945—2026 "Water Pollutant Emission Standard for the Chishui River Basin" (the first watershed national standard for the core production area of Jiang-flavor baijiu, dividing three types of control zones and improving the benchmark water discharge per unit product for the fermented alcohol and baijiu manufacturing industries) was also implemented. Together, they constitute the first systematic implementation of "one river, one policy" at the national standard level.

II. Characteristic Pollutants: Bringing Antimony and Molybdenum into Mandatory Control

The most substantive breakthrough of the standard lies in advancing total antimony and total molybdenum from "research indicators" to "emission limits."

Antimony and molybdenum are not conventional pollutants in the traditional sense. They are mainly generated alongside mining and ore dressing, non-ferrous smelting, and certain chemical processes, and have long lacked targeted limits in conventional emission standards, often only being addressed on a case-by-case basis through "characteristic pollutants" in environmental impact assessments or pollutant discharge permits. The result is that even if enterprises meet all conventional indicators, characteristic pollutants may still continuously enter water bodies, while regulators lack a unified basis for determination.

GB 47946—2026 fills this gap. For mining, smelting, and chemical enterprises upstream of the Danjiangkou Reservoir Area, the impact is direct:

• Identify pollution generation and discharge nodes—sort out the sources and fates of antimony and molybdenum in raw materials, processes, and wastewater treatment stages
• Conduct self-monitoring—establish monitoring capabilities for characteristic pollutants in accordance with standard requirements, forming traceable data records
• Develop retrofit plans—complete compliance retrofits before the 2028年1月1日 transition period deadline
• Incorporate into pollutant discharge permits—local ecological and environmental departments will include characteristic pollutants in pollutant discharge permits, forming normalized constraints

III. Triple Coverage of "Point Sources—Non-Point Sources, Conventional—Characteristic, Traditional—New"

The control framework established by the standard can be understood through three sets of contrasting relationships:

• Equal emphasis on point sources and non-point sources—not only controlling identifiable and measurable point sources such as industrial enterprise discharge outlets, but also imposing control requirements on non-point sources such as agricultural runoff and dispersed discharges upstream of the reservoir area
• Equal emphasis on conventional and characteristic pollutants—in addition to conventional indicators such as COD and ammonia nitrogen, regional characteristic pollutants such as antimony and molybdenum are simultaneously included
• Equal emphasis on traditional and new sources—the scope of control is not limited to existing emission sources, but also reserves applicable space for new types of emission sources

This framework design, together with a batch of new standards that took effect collectively on 2026年9月, exhibits a common methodological shift. Also implemented during the same period are HJ 945.4—2026 "Technical Guideline for the Formulation of Water Pollutant Emission Standards for Centralized Wastewater Treatment Facilities in Industrial Parks" (China's first guideline for formulating park wastewater standards) and HJ 1467—2026 "Technical Guideline for the Formulation of Watershed Water Ecological Environment Quality Standards." Both guidelines are also directly implemented from 2026年9月1日 with no transition period. Their common feature is that standards no longer only provide "end-of-pipe limits," but provide the methodology for "how to formulate standards."

IV. Comprehensive Toxicity: Meeting Physicochemical Standards Does Not Mean Wastewater Is Compliant

Among this batch of 9月 new regulations, there is another signal worthy of close industry attention—"comprehensive toxicity" is becoming a new regulatory red line.

GB 4287—2026 "Discharge Standard of Water Pollutants for Textile Industry" has newly added a zebrafish embryo acute toxicity pollutant item and its discharge limits; Amendment No. 1 to GB 18466—2005 "Discharge Standard of Water Pollutants for Medical Institutions" (GB 18466-2005/XG1-2026, pursuant to Announcement No. 28 of the Ministry of Ecology and Environment 2026年, with mandatory enforcement effect) has also newly added a zebrafish embryo acute toxicity indicator for medical institutions engaged in direct discharge, used to control the risks of emerging pollutants such as antibiotics.

The essence of this change is: past compliance determinations were built on the assumption that "every indicator is within its limit," but when multiple pollutants coexist, synergistic toxicity may occur, which single-indicator compliance cannot reflect. Biological toxicity indicators directly answer from the outcome end "whether this stream of water is actually toxic or not," upgrading the regulatory logic from "item-by-item comparison" to "overall effect evaluation." For enterprises adopting advanced treatment and reuse processes, this means the dimensions for evaluating effluent have increased, and process validation needs to simultaneously cover biological toxicity testing.

This amendment also includes several adjustments with broad impact: newly added wastewater control for "dual-use for peacetime and emergency" public infrastructure; small medical institutions with fewer than 20 beds must meet quantitative limits for fecal coliforms, total residual chlorine, etc. (previously only required discharge after disinfection, with no quantitative indicators); clarified mandatory requirements for diversion and pre-disinfection of wastewater from infectious disease areas; sludge from medical wastewater treatment is no longer classified as hazardous waste, but must be transferred for disposal after disinfection. Newly built, reconstructed, and expanded institutions shall implement from 2026年9月1日, and existing institutions transition until 2028年9月1日.

V. Three Implications for the Water Treatment Industry

First, basin differentiation will give rise to demand for customized processes. General-purpose process packages can hardly simultaneously meet the removal requirements for characteristic pollutants such as antimony and molybdenum; the market space for targeted advanced treatment units such as adsorption, coagulation-sedimentation, and membrane separation will be opened up, especially for centralized treatment facilities serving mines, smelting, and industrial parks.

Second, monitoring capability is a prerequisite investment for compliance. The premise of characteristic pollutant control is "accurate measurement and affordable measurement." Online monitoring equipment, third-party testing services, and consulting for pollutant discharge permit filing will usher in a round of demand release.

Third, the transition period is the window period. New enterprises 2026年9月1日, existing enterprises 2028年1月1日—for incumbent enterprises, there are still about two years to complete process diagnosis and transformation. Whoever completes the technical reserve first will be able to seize the initiative in the regional standard-raising market.

From "one ruler measuring everything the same way" to "one key opening one lock," China's water pollutant discharge standard system is completing a silent but profound restructuring. GB 47946—2026 is the most iconic piece of this round of restructuring.

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