Ill. Admin. Code tit. 35, § 364.207 - Classification of Aquatic Environments

Aquatic environments are classified according to the following:

a) Balanced environment: Intolerant organisms are many in number and species, or more in numbers than other forms present.

Intolerant present [GREATER THAN]50%

Moderate, facultative and tolerant usually present [LESS THAN] 50%

b) Unbalanced environment: Intolerant organisms are less in number than other forms combined, but combined with moderate forms, they usually outnumber tolerant forms.

Intolerant present [LESS THAN] 50% but [GREATER THAN]10%

Moderate, facultative and tolerant usually present [GREATER THAN] 50%

c) Semi-polluted environment: Intolerant organisms are few or may not be present. Moderate and/or facultative organisms present.

Intolerant present [GREATER THAN]10%

Moderate, facultative and tolerant usually present [GREATER THAN] 90%

d) Polluted environment:

1) Intolerant organisms absent, only tolerant organisms present or no organisms present.

Tolerant present = 100%

2) Organisms which are not adapted to inhabit a polluted environment are occasionally collected as a result of factors produced by the drift and are not representative.

Notes

Ill. Admin. Code tit. 35, § 364.207