Section 304.122  Total Ammonia Nitrogen

a)         Effluent from any source that discharges into the Illinois River, the Des Plaines River downstream of its confluence with the Chicago River System, or the Calumet River System, and whose untreated waste load is 50,000 or more population equivalents must not contain more than 2.5 mg/L of total ammonia nitrogen as N during the months of April through October, or 4 mg/L at other times.

b)         Sources discharging to any of the above waters and whose untreated waste load cannot be computed on a population equivalent basis comparable to that used for municipal waste treatment plants and whose total ammonia nitrogen as N discharge exceeds 45.4 kg/day (100 pounds per day) must not discharge an effluent of more than 3.0 mg/L of total ammonia nitrogen as N.

c)         In addition to the effluent standards in subsections (a) and (b), all sources are subject to Section 304.105

(Source:  Amended at 47 Ill. Reg. 4601, effective March 23, 2023)