35 Ill. Adm. Code 373.304
Stream Assimilative Capacity
Section 373
Section 373.304 Stream
Assimilative Capacity
a) Unless conditions as described in Appendix D indicate
otherwise, the applicant shall use the Modified Streeter-Phelps Equation
contained in Appendix B to predict the influence of the treated wastewater
discharge on the dissolved oxygen profile of the receiving stream.
b) The critical conditions for estimating the stream assimilative
capacity shall include:
1) the 7-day 10-year low flow value,
2) ambient BOD
5,
3) ambient total ammonia nitrogen concentration,
4) ambient dissolved oxygen concentration,
5) the lagoon system discharge at its design average flow rate
and design effluent quality,
6) expected maximum stream temperature, and
7) other hydraulic parameters as described in Appendix C.