Class name

Igeo value range

Classification

0

I_geo ≤ 0

Practically uncontaminated

1

0 < I_geo ≤ 1

Uncontaminated to moderately contaminated

2

1 < I_geo ≤ 2

Moderately contaminated

3

0 < I_geo ≤ 3

Moderately to heavily contaminated

4

0 < I_geo ≤ 4

Heavily contaminate

5

0 < I_geo ≤ 5

Heavily to extremely contaminated

6

0 < I_geo ≤ 6

Extremely contaminated