40 CFR § 418.60
Applicability; description of the ammonium sulfate production subcategory
June 9, 2020
The provisions of this subpart apply to discharges resulting from the production of ammonium sulfate by the synthetic process and by coke oven by-product recovery. The provisions of this subpart do not apply to ammonium sulfate produced as a by-product of caprolactam production.