40 CFR §1700.14

1. (a)For the purposes of this section, regulated aqueous film-forming foam (AFFF) refers only to firefighting foam and seawater mixture discharged during training, testing, or maintenance operations.
2. (b)For all vessels that sail seaward of waters subject to UNDS at least once per month, the discharge of AFFF is prohibited.
3. (c)For all vessels that do not sail seaward of waters subject to UNDS at least once per month:
   1. (1)The discharge of fluorinated AFFF is prohibited; and
   2. (2)The discharges of non-fluorinated or alternative foaming agent are prohibited in port or in or near federally-protected waters, and must occur as far from shore as possible.