China water quality standards

National Standard of the People’s Republic of China: Environmental Quality Standards for Surface Water

This Standard is drawn up for the implementation of the Environmental Protection Law of the Peoples' Republic of China and the Law of Prevention and Control of Water Contamination of the Peoples' Republic of China for controlling water contamination, protecting water resources, ensuring human health and maintaining ecological equilibrium.

In this Standard, the standard items are divided to basic items and specific items. Basic items are suitable for surface water area including rivers, lakes, canals, channels and reservoirs with utilization function in the whole country. These are the basic water quality requirements so as to meet the stipulated utilization function and ecological environment quality. The specific items are suitable for control of the specific contaminants in the specific surface water areas. These items will be selected as the supplementary index for basic items by administrative departments in charge of environmental protection in peoples' government above county - level according to the demand of local environmental management.

There are 109 items in this Standard, among which, 24 are basic items of environment quality standard of surface water, 5 items for supplementary items of centralized potable water source and 80 items for the specific items of centralized potable water source. Comparing with GHZB 1-1999, added total nitrogen item into basic items of environment quality standard of surface water, deleted three indexes such as basic requirements, nitrite and TKN, adjusted the sulfate, chloride, nitrate, Fe and Mn to supplementary items of centralized potable water source, revised the standard value of seven items such as PH, DO, ammonia nitrogen, total phosphorus, permanganate index, lead and fecal coliforms, added 40 items specific items of centralized potable water source; Deleted the standard value of specific item of lake and reservoir in this Standard.

This Standard is to be supervised and implemented coordinately by the department of environmental protection administration of governments above the county level and the related department.

Scope

- This Standard specifies the water quality items, standard values, water quality evaluation and analysis method of water quality items as well as implementation and supervision of standard based on the environmental functions classification of surface water and protection target-related.

- This Standard is application to surface water area with utilizable functions of national rivers, lakes, canals, channels and reservoirs in People's Republic of China. For the water area with specific functions, shall be in accordance with related specialty water quality standards.

Classification for WaterArea Functions

Surface water is divided into five classes according to its purpose for use and protection target.

Class 1: mainly for source of water and national nature protection areas;

Class II: mainly for class one protection areas for centralized potable water source, protection areas for rare fishes, spawn ground for fishes and shrimps, etc.

Class III: mainly for class two protection areas for centralized potable water source, protection areas for general fishes and swimming areas.

Class IV: mainly for general industrial water areas and entertainment water areas not directly touched by body.

Class V: mainly for farmland water areas and water areas for general landscape requirement.

Corresponding to above five functions in water areas of surface water, divided the standard value of basic items of environment quality standard of surface water into five classes, different function will be taken for corresponding standard value respectively. The standard value with high class water area function is stricter than the lower. If there are several classes of function in the same water areas, the highest class of function will be taken for classification. To implement water area functions and reaches classification of the function is same system.

The standard values for basic items of environmental quality standards of surface water will follow Table 1.

Table 1: The standard values for basic items of environmental quality standards of surface water

		Classification/ Standard value	Classification/ Standard value	Classification/ Standard value	Classification/ Standard value	Classification/ Standard value
item No.	Items	Class I	Class II	Class III	Class IV	Class V
1	Water temperature (℃)	Ambient water temperature change caused by man-made reasons shall be limited at: Maximum weekly average temperature rise ≤ 1 Maximum weekly average temperature drop ≤ 2
2	pH (Dimensionless)	6 ～ 9
3	Dissolved oxygen ≥	Saturation rate 90% (or 7.5)	6	5	3	2
4	Permanganate index ≤	2	4	6	10	15
5	Chemical oxygen demand (COD) ≤	15	15	20	30	40
6	Biochemical oxygen demand in five days (BOD₅) ≤	3	3	4	6	10
7	Ammonia & nitrogen (NH3-N) ≤	0.15	0.5	1.0	1.5	2.0
8	Total phosphorus（as P） ≤	0.02 (lake & Reservoir 0.01)	0.1 (lake & Reservoir 0.025)	0.2 (lake & Reservoir 0.05)	0.3( lake & Reservoir 0.1)	0.4 (lake & reservoir 0.2)
9	Nitrate (lake & reservoir, as N） ≤	0.2	0.5	1.0	1.5	2.0
10	Copper ≤	0.01	1.0	1.0	1.0	1.0
11	Zinc ≤	0.05	1.0	1.0	2.0	2.0
12	Fluoride （as F- ） ≤	1.0	1.0	1.0	1.5	1.5
13	Selenium ≤	0.01	0.01	0.01	0.02	0.02
14	Arsenic ≤	0.05	0.05	0.05	0.1	0.1
15	Hg ≤	0.00005	0.00005	0.0001	0.001	0.001
16	Cadmium ≤	0.001	0.005	0.005	0.005	0.01
17	Chromium （hexad） ≤	0.01	0.05	0.05	0.05	0.1
18	Lead ≤	0.01	0.01	0.05	0.05	0.1
19	Cyanide ≤	0.005	0.05	0.2	0.2	0.2
20	Volatilization Hydroxybenzene ≤	0.002	0.002	0.005	0.01	0.1
21	Petroleum ≤	0.05	0.05	0.05	0.5	1.0
22	Anionic surfactant ≤	0.2	0.2	0.2	0.3	0.3
23	Sulphide ≤	0.05	0.1	0.2	0.5	1.0
24	Dung large intestine bacterium group (numbers/L) ≤	200	2000	10000	20000	40000