Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 364 - PROCEDURES AND REQUIREMENTS FOR DETERMINING CONSTRUCTION GRANT PRIORITIES FOR MUNICIPAL SEWAGE TREATMENT WORKS NEEDS
Subpart B - PROCEDURE FOR CALCULATING THE MUNICIPAL DISCHARGE INDEX
Section 364.207 - Classification of Aquatic Environments
Current through Register Vol. 48, No. 38, September 20, 2024
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.
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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.
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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.
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Intolerant present >10% |
Moderate, facultative and tolerant usually present > 90% |
d) Polluted environment:
Tolerant present = 100%
