33 CFR 155.400: Machinery space drainage on oceangoing platforms

Last reviewed: October 14, 2026

This section covers oily drainage from machinery spaces on oceangoing fixed and floating drilling rigs and other platforms. No person may operate one unless it meets one of three equipment options. Extra limits apply in a special area, when not proceeding en route, or within 12 nautical miles of the nearest land.

Applies toOceangoing fixed or floating drilling rigs and other platforms.

What it says

  1. No person may operate an oceangoing fixed or floating drilling rig or other platform unless it meets one of the three options in paragraph (a).

    33 CFR 155.400(a)“No person may operate an oceangoing fixed or floating drilling rig or other platform unless it either—”

  2. One option is to comply with the oily-water separating equipment requirements of a valid NPDES permit issued under section 402 of the Clean Water Act and 40 CFR Chapter I.

    33 CFR 155.400(a)(1)“Complies with the oily-water separating equipment requirements of a valid National Pollutant Discharge Elimination System (NPDES) permit”

  3. A second option is to comply with the oily-water separating equipment requirements for oceangoing ships of 400 gross tons and above set out in § 155.360 or § 155.370.

    33 CFR 155.400(a)(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”

  4. A third option is to have no installed bilge pumping system for discharging oily mixtures from machinery spaces into the sea, to be able to retain all of these mixtures on board, and to be equipped to discharge them for transport to a reception facility.

    33 CFR 155.400(a)(3)“Is not equipped with an installed bilge pumping system for discharge of oily mixtures from platform machinery spaces into the sea”

  5. In a special area, when not proceeding en route, or within 12 nautical miles of the nearest land, the platform must meet paragraph (b)(1) or (b)(2).

    33 CFR 155.400(b)“is in a special area, is not proceeding en route, or is within 12 nautical miles of the nearest land; it must either—”

  6. One choice is to be able to retain all machinery space oily mixtures on board and be equipped to discharge them for transport to a reception facility.

    33 CFR 155.400(b)(1)“Have the capacity to retain on board all machinery space oily mixtures from platform machinery space drainage”

  7. The other choice is to discharge in accordance with § 151.10 (b)(3), (b)(4), and (b)(5) of this chapter, but only if the platform is not within a special area.

    33 CFR 155.400(b)(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.”

  8. Paragraph (b) does not apply to a fixed or floating drilling rig or other platform operating under an NPDES permit.

    33 CFR 155.400(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.”

Common questions

Does 33 CFR 155.400 apply to platforms operating under an NPDES permit?

Paragraph (b), the special area, en route and 12 nautical mile rule, does not apply to a platform operating under an NPDES permit. Paragraph (a) still sets the options for operating.

“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.”

Can a platform discharge machinery space oily mixtures in a special area?

Not under paragraph (b)(2). That discharge option is allowed only if the platform is not within a special area. In a special area, the platform must retain the mixtures under paragraph (b)(1).

“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.”

What are the options for a platform with no bilge pumping system?

It must be able to retain all of these oily mixtures on board and be equipped to discharge them for transport to a reception facility.

“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.”

The text of 33 CFR 155.400

Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR

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.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.