Section 139.22 - Hulls and associated niche areas(a)Applicability. The requirements in paragraphs (b) through (d) of this section apply to the discharge of anti-fouling coatings, biofouling organisms, and other materials from vessel hull and niche areas.(b)Transport and passive discharge. The transport of attached living organisms and passive discharge of biofouling must be minimized when traveling into U.S. waters from outside the EEZ or between COTP Zones. Management measures to minimize the transport of attached living organisms and the passive discharge of biofouling are described in paragraphs (c) and (d) of this section.(c)Anti-fouling coatings.(1) Anti-fouling coatings applied to the vessel must be specific to the operational profile of the vessel and the equipment to which it is applied, including, for biocidal coatings, having appropriate biocide release rates and components that are biodegradable once separated from the vessel surface.(2) Anti-fouling coatings must be applied, maintained, and reapplied consistent with manufacturer specifications, including but not limited to the thickness, the method of application, and the lifespan of the coating.(3) Anti-fouling coatings must not contain tributyltin (TBT) or any other organotin compound used as a biocide.(i) Any vessel hull previously covered with an anti-fouling coating containing TBT (whether or not used as a biocide) or any other organotin compound (if used as a biocide) must:(A) Maintain an effective overcoat that forms a barrier so that no TBT or other organotin leaches from the underlying anti-fouling coating; or(B) Remove any TBT or other organotin compound from the vessel hull.(4) When an organotin compound other than TBT is used as a catalyst in the anti-fouling coating (e.g., dibutyltin), the anti-fouling coating must: (i) Contain less than 2,500 mg total tin per kilogram of dry paint; and(ii) Not be designed to slough or otherwise peel from the vessel hull, noting that incidental amounts of anti-fouling coating discharged by abrasion during cleaning or after contact with other hard surfaces (e.g., moorings) are acceptable.(5) Anti-fouling coatings must not contain cybutryne.(i) Any vessel that has previously applied an anti-fouling coating that contains cybutryne in the external coating layer of their hulls or external parts or surfaces must: (A) Apply and maintain an effective overcoat that forms a barrier so that no cybutryne leaches from the underlying anti-fouling coating, noting that incidental amounts of anti-fouling coating discharged by abrasion during cleaning or after contact with other hard surfaces (e.g., moorings) are acceptable; or(B) Remove any cybutryne coating.(6) As appropriate based on vessel class and operations, alternatives to copper-based anti-fouling coatings (e.g., non-biocidal anti-fouling coatings) or coating with lower biocidal release rates must be considered for vessels spending 30 or more days per year in a copper-impaired waterbody or using these waters as their home port.(d)Cleaning.(1) Cleanings should take place in drydock when practicable.(2) Hulls and niche areas must be managed to minimize biofouling such as through preventative cleaning of microfouling.(3) Hull and niche area cleanings must minimize damage to the anti-fouling coating, minimize release of biocides, and follow applicable cleaning requirements found on the coating manufacturers' instructions and any applicable FIFRA label.(4) Any discharge from in-water cleaning without capture of macrofouling is prohibited.(5) Any discharge from in-water cleaning without capture of any copper-based hull coating in a copper-impaired water body within the first 365 days after application of that coating is prohibited.(6) In-water cleaning must not be conducted on any section of an anti-fouling coating that shows excessive cleaning actions (e.g., brush marks) or blistering due to the internal failure of the paint system.(7) Any soap, cleaner, or detergent used on vessel surfaces, including but not limited to a scum line of the hull, must be minimally toxic, phosphate-free, and biodegradable.(8) Additional standards applicable to discharges from hulls and associated niche areas when a vessel is operating in federally-protected waters are contained in § 139.40(i).