§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 >50%

Moderate, facultative and tolerant usually present < 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 < 50% but >10%

Moderate, facultative and tolerant usually present > 50%

 

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

 

Intolerant present >10%

Moderate, facultative and tolerant usually present > 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.