Classes

Parameters

1

2

3

4

5

6

DBO₅ (mg_O2/L)

<1

1 - 3

3 - 6

6 - 15

>15

Ammonium ( ${\text{NH}}_4^{+}$ ) (mg/L)

<0.1

0.1 - 0.5

0.5 - 2

2 - 8

>8

Phosphate ( ${\text{PO}}_4^{3-}$ ) (mg/L)

<10

10 - 50

50 - 150

150 - 300

300 - 500

>500

Nitrate ( ${\text{NO}}_3^{-}$ ) (mg/L)

<1

1 - 3

3 - 5

5 - 10

10 - 15

>15