Heavy metals

Maximum allowable in irrigation water

Values for water at sampling site (mg/I)

Values for soil at various depth

0 - 15 cm

15 - 30 cm

Pb

-

0.05

0.8

0.3

Cu

0.2

0.05

0.1

0.2

Zn

Up to 5.0

0.04

1.8

1.0

Mn

0.2

0.08

2.4

1.7

Ni

0.2

0.07

2.1

1.1

As

0.1

0.05

1.6

0.8

Cr

0.1

0.09

1.0

0.5

Fe

0.01

0.2

0.8

0.6