Section 155.400 - Platform machinery space drainage on oceangoing fixed and floating drilling rigs and other platforms(a) No person may operate an oceangoing fixed or floating drilling rig or other platform unless it either-(1) Complies with the oily-water separating equipment requirements of a valid National Pollutant Discharge Elimination System (NPDES) permit issued in accordance with section 402 of the Clean Water Act and 40 CFR Chapter I;(2) Complies with the oily-water separating equipment requirements for oceangoing ships of 400 gross tons and above as set forth in either § 155.360 or § 155.370 ; or(3) Is not equipped with an installed bilge pumping system for discharge of oily mixtures from platform machinery spaces into the sea and has the capacity to retain on board all of these oily mixtures and is equipped to discharge these mixtures for transport to a reception facility.(b) When an oceangoing fixed or floating drilling rig or other platform is in a special area, is not proceeding en route, or is within 12 nautical miles of the nearest land; it must either-(1) Have the capacity to retain on board all machinery space oily mixtures from platform machinery space drainage and be equipped to discharge these mixtures for transport to a reception facility; or(2) Discharge in accordance with § 151.10 (b)(3), (b)(4), and (b)(5) of this chapter, provided the drilling rig or platform is not within a special area.(c) Paragraph (b) of this section does not apply to a fixed or floating drilling rig or other platform that is operating under an NPDES permit.CGD 75-124a, 48 FR 45715, Oct. 6, 1983, as amended by CGD 88-002, 54 FR 18407, Apr. 28, 1989; CGD 94-056, 60 FR 43378, Aug. 21, 1995; USCG-1998-3799, 63 FR 35531, June 30, 1998