35 Ill. Adm. Code 364.301
Formula for the Segment Ranking Index
Section 364
Section 364.301 Formula for
the Segment Ranking Index
a) The Segment Ranking Index (SRI) is an objective determination
of the priority of segments through the use of four factors which are expressed
as numerical factors and combined to establish a ranking index for each of the
basin segments.
b) The SRI is calculated as follows
SRI = Water
Quality Index (WQI) x High Quality Water Factor x Population Factor x National
Priorities Factor