Relevant water quality standards

Sanitary Standard for Drinking Water GB

Surface water environmental quality standard GB

Urban sewage treatment plant pollutant discharge standard GB

Fishery Water Quality Standard GB

Primary standard

Secondary standard

Third level standard

Class I

Class II

Class III

Class IV

Class V

A standard

B standard

Total coliforms / (MPN / 100mL or CFU / 100mL)

Not checked out

Not more than 5000 / L (the shellfish culture water quality does not exceed 500 / L)

Fecal coliforms (units/L)

200

2000

10000

20000

40000

10^3

10^4

10^4

Chroma (platinum cobalt color unit)

15

30

30

40

50

Turbidity / NTU)

1

pH

6.5~8.5

6~9

6~9

Fresh water 6.5~8.5, sea water 7.0~8.5

Dissolved oxygen / (mg / L)

Saturation rate 90% (or 7.5)

6

5

3

2

For 24 hours in a row, the above 16h must be greater than 5, and the rest must not be lower than 3 at any time. For any other period of the frozen waters of the salmonids, it must be no less than 4 at any time.

Permanganate index / (mg / L)

3 (water source limit, when the raw water oxygen consumption>6mg/L is 5)

2

4

6

10

15

Chemical oxygen demand (COD) / (mg / L)

15

15

20

30

40

50

60

100

100

Five-day biochemical oxygen demand (BOD ₅ ) / (mg / L)

3

3

4

6

10

10

20

30

60

No more than 5, the ice age is no more than 3

Petroleum / (mg / L)

0.05

0.05

0.05

0.1

0.1

1

3

5

15

0.05