The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium nitrate. Discharges attributable to shipping losses, precipitation runoff from outside the battery limits of the ammonium nitrate manufacturing operations, cooling tower blowdown, and discharges from plants which totally condense their neutralizer overheads are excluded.
40 C.F.R. §418.40
Sec. 306(b), Federal Water Pollution Control Act, as amended (33 U.S.C. 1316(c)