TITLE 35: ENVIRONMENTAL PROTECTION
SUBTITLE C: WATER POLLUTION
CHAPTER I: POLLUTION CONTROL BOARD
PART 302 WATER QUALITY STANDARDS
SECTION 302.658 STREAM FLOW FOR APPLICATION OF HUMAN NONTHRESHOLD CRITERION
SUBTITLE C: WATER POLLUTION
CHAPTER I: POLLUTION CONTROL BOARD
PART 302 WATER QUALITY STANDARDS
SECTION 302.658 STREAM FLOW FOR APPLICATION OF HUMAN NONTHRESHOLD CRITERION
Section 302.658 Stream Flow for Application of Human Nonthreshold Criterion
The HNC applies at all times except during periods when flows are less than the harmonic mean flow (Qhm), as determined by:
Qhm = N / SUM(1/Qi)
Where:
|
Qhm |
= |
harmonic mean flow, |
|
N |
= |
number of daily values for streamflows, and |
|
Qi |
= |
daily streamflow value on day i. |
(Source: Amended at 47 Ill. Reg. 4437, effective March 23, 2023)