MARPOL Annex IV Reg 14: Port State Control on Sewage

MARPOL Annex IV Regulation 14, “Port State control on operational requirements”, is the rule that lets a port State inspect how a foreign ship actually runs its sewage system, not only whether it holds a sewage certificate. It applies where there are clear grounds for believing that the master or crew are not familiar with essential shipboard procedures for preventing pollution by sewage, and it obliges the port State to stop the ship sailing until the situation is brought to order. It is the single regulation of Chapter 5 of the revised MARPOL Annex IV , and IMO Resolution A.1206(34), the Procedures for Port State Control, 2025, lists it in paragraph 1.4 as “regulation 14 of Annex IV”.

The regulation was inserted in 2006 as Regulation 13 and became Regulation 14 when the special-area amendments of Resolution MEPC.200(62) entered into force on 1 January 2013. Older manuals, company checklists and some training material still cite Regulation 13, which today is the reception-facility rule for passenger ships in special areas.

A valid International Sewage Pollution Prevention Certificate proves that a ship passed a survey. Regulation 14 tests the period since: whether the sewage treatment plant runs, whether the crew can start it and explain it, and whether discharges respected the distance and speed conditions of Regulation 11 . That makes it the enforcement end of the Annex, and the reason a ship with clean papers can still be detained over sewage.

Regulation 14 text and its four paragraphs

Regulation 14 has four paragraphs, unchanged in substance since Resolution MEPC.143(54) inserted them on 24 March 2006 with effect from 1 August 2007. The text, as adopted, reads:

1. A ship when in a port or an offshore terminal of another Party is subject to inspection by officers duly authorized by such Party concerning operational requirements under this Annex, where there are clear grounds for believing that the master or crew are not familiar with essential shipboard procedures relating to the prevention of pollution by sewage.

2. In the circumstances given in paragraph (1) of this regulation, the Party shall take such steps as will ensure that the ship shall not sail until the situation has been brought to order in accordance with the requirements of this Annex.

3. Procedures relating to the port State control prescribed in article 5 of the present Convention shall apply to this regulation.

4. Nothing in this regulation shall be construed to limit the rights and obligations of a Party carrying out control over operational requirements specifically provided for in the present Convention.

(MEPC.143(54), Annex, new Chapter 5.)

Paragraph 1 sets the trigger and the place. The ship must be in a port or offshore terminal of a Party other than its flag State, and the officer must be duly authorized by that Party. The ground named is crew unfamiliarity with sewage procedures, which is narrower than the general Article 5 ground about the ship’s condition.

Paragraph 2 is the obligation, and it is written as a duty, not a discretion: the Party shall take steps so that the ship does not sail until the situation is brought to order. Paragraph 3 imports the Article 5 procedures of the Convention, including the repair-yard release and the duty to inform the flag State. Paragraph 4 is a savings clause. It keeps the control powers that other parts of MARPOL give a Party, so Regulation 14 adds to Articles 5 and 6 rather than replacing them.

The regulation does not set any sewage standard: equipment is Regulation 9 , the shore connection is Regulation 10 , and discharge is Regulation 11. Nor does it mention the IMO Procedures for Port State Control. The link to A.1206(34) runs through the Assembly’s invitation to Governments, not through the regulation text.

Why older sources cite Regulation 13

The port State control regulation was numbered 13 from 1 August 2007 to 31 December 2012 and has been Regulation 14 since 1 January 2013. The change came from the Baltic Sea special-area amendments, not from any change to the control provision itself.

The sequence, from the IMO resolution texts, runs as follows:

The correction of 27 June 2014 corrects the certified text of amendments that had already entered into force on 1 January 2013, so the renumbering takes effect from that date rather than from 2014. MEPC.246(66), adopted a year after the amendments entered into force, numbers its new Annex IV regulations 15 and 16, which only works if 13 and 14 are taken.

The Assembly’s Procedures followed the same change. Resolution A.1052(27), adopted 30 November 2011, before the amendments entered into force, still listed “regulation 13 of Annex IV”. Resolutions A.1138(31) of 4 December 2019, A.1155(32) of 15 December 2021, A.1185(33) of 6 December 2023 and A.1206(34) of 3 December 2025 all list “regulation 14 of Annex IV”. A.1206(34) Appendix 7 repeats it twice, at paragraph 5.2.2 Note 1 and paragraph 8.2.5.

Regulation 13 today is “Reception facilities for passenger ships in Special Areas”. Resolution MEPC.275(69), adopted 22 April 2016, refers to “regulation 13.2 of MARPOL Annex IV” as the reception-facility notification that fixed the Baltic dates. A Paris MoU or Tokyo MoU deficiency recorded against “Annex IV Regulation 13” today refers to reception facilities, so an operator reading an older internal procedure should correct the reference before relying on it. The reception-facility rule is covered in Annex IV Regulation 13 for passenger ships in special areas .

The treaty basis: MARPOL Articles 4 to 7 and UNCLOS

Regulation 14 rests on four articles of the 1973 Convention, done at London on 2 November 1973. Each does a separate job, and an inspection report that cites the wrong one invites challenge.

Article 5, certificates and inspection. Article 5(1) requires every Party to accept a certificate issued under the authority of another Party. Article 5(2) then makes a ship required to hold a certificate subject, in the ports or offshore terminals of a Party, to inspection by officers duly authorized by that Party. That inspection is “limited to verifying that there is on board a valid certificate”, unless there are clear grounds for believing that the condition of the ship or its equipment does not correspond substantially with the particulars of the certificate. In that case the Party shall take steps so that the ship does not sail “until it can proceed to sea without presenting an unreasonable threat of harm to the marine environment”, and may permit it to leave for “the nearest appropriate repair yard available”. Article 5(3) requires the Party to inform the consul or diplomatic representative of the flag State, or the Administration, when it denies a ship entry or takes action under the article.

Article 5(4), no more favourable treatment. Parties apply the Convention’s requirements to ships of non-Parties as necessary to ensure that no more favourable treatment is given to those ships. That is why a ship flagged in a State that has not accepted Annex IV is still inspected against it in the port of a Party. The principle and its counterparts in SOLAS, STCW, AFS and BWM are covered at no more favourable treatment .

Article 6, detection and evidence. Article 6 lets a Party inspect a ship in its ports or offshore terminals to verify whether it has discharged harmful substances in violation of the regulations, and requires a report of an indicated violation to be forwarded to the flag Administration. Article 6(4) has the Administration investigate on receipt of the evidence. This is the article that governs a suspected discharge, for example a report of untreated sewage released inside 12 nautical miles.

Article 4, the violation itself. Article 4(2) deals with a violation committed within the jurisdiction of a Party: that Party either causes proceedings to be taken under its own law or furnishes the flag Administration with the information and evidence it has. The proceedings-or-evidence choice belongs to Article 4(2), not to Article 6.

Article 7, undue delay. Article 7(1) requires all possible efforts to avoid a ship being unduly detained or delayed under Articles 4, 5 or 6, and Article 7(2) entitles a ship unduly detained or delayed to compensation for any loss or damage suffered. Undue detention compensation covers how that claim is pursued.

UNCLOS frames the same powers from the law of the sea side. Article 226(1)(a) of the United Nations Convention on the Law of the Sea limits physical inspection of a foreign ship to its certificates and records unless there are clear grounds, the documents are insufficient, or the ship carries no valid certificates. Article 218 gives a port State enforcement jurisdiction over discharges beyond its own waters when the ship is voluntarily in its port, and Article 219 covers ships in breach of seaworthiness rules that threaten damage to the marine environment. The wider doctrine is at port State jurisdiction .

Clear grounds for a sewage inspection

Clear grounds are the evidence that lets an officer go past the certificate into the operation of the sewage system. Without them, MARPOL Article 5(2) confines the inspection to the certificate; with them, Regulation 14 and Article 5 open the equipment, the records and the crew.

The A.1206(34) definition and the nine categories

A.1206(34) paragraph 1.7.2 defines clear grounds as evidence that the ship, its equipment or its crew does not correspond substantially with the requirements of the relevant conventions, or that the master or crew members are not familiar with essential shipboard procedures relating to the safety of ships or the prevention of pollution. Paragraph 2.4.2 then lists nine categories. Those that bear on sewage are:

• invalid certificates, which includes an expired ISPP Certificate or one issued for another ship;
• serious deficiencies in pollution-prevention equipment, such as a treatment plant tripped out with its bypass open;
• evidence that the crew is not familiar with essential shipboard operations relating to pollution prevention;
• documents required by Appendix 12 part A missing or falsely maintained;
• a report or complaint containing information that the ship appears to be substandard.

The other four categories, covering principal equipment, hull deterioration, crew communication and uncancelled false distress alerts, can bring an officer into the engine room for a different reason, after which a sewage finding is recorded in the usual way. The full list is analysed at clear grounds in port State control .

For sewage, the most frequent practical trigger is a mismatch between the certificate and the engine room. The ISPP Certificate records which of the three Regulation 9 options the ship relies on: an approved sewage treatment plant, a comminuting and disinfecting system with temporary storage, or a holding tank. An officer who finds a holding tank where the certificate records a treatment plant, or a plant with a different type-approval reference, has the Article 5(2) ground directly.

Complaints and reports

A.1206(34) paragraph 2.1.2 lists the ways an inspection can start: the port State’s own initiative, a request from another Party, or information from a crew member, a professional body, an association, a trade union or any other individual. Paragraph 2.3.4 requires the officer not to disclose the source of a complaint to the master or the shipowner.

Sewage complaints can come from harbor authorities that see discoloured water or floating solids near a berth, crew members who are told to open an overboard valve alongside, or reception-facility operators who note that a ship arriving from a long passage delivered nothing. Any of them can give clear grounds. A report of a discharge rather than a familiarity problem also engages Article 6, so the officer records the evidence in a form the flag Administration can use. A.1206(34) paragraph 4.3.1 asks for MARPOL violation reports to reach the flag State preferably no later than 60 days after the inspection.

What the officer checks

An operational sewage inspection under Regulation 14 has five strands: the certificate, the equipment, the discharge arrangements, the records the ship keeps, and the crew’s familiarity. A.1206(34) gives the officer explicit authority on the equipment and the crew. Its Annex IV guidance says the officer may determine whether the sewage treatment plant, comminuting and disinfecting system or holding tank “has been used”, and whether the crew is familiar with its operation and with the discharge requirements of Regulation 11.

ISPP Certificate, paper or electronic

The ISPP Certificate is item 14 on the A.1206(34) list of certificates and documents, referenced to “MARPOL Annex IV regulation 5.1 and MEPC.1/Circ.408”. It is issued under Regulation 5 after the initial or renewal survey under Regulation 4, in the form set by Regulation 7, for a period not exceeding five years under Regulation 8. The officer checks that the certificate is on board, is in date, matches the ship’s name, IMO number and port of registry, and records the equipment actually fitted.

A.1206(34) paragraph 1.7.12 defines valid certificates as issued “electronically or on paper”, and paragraph 2.2.3 accepts electronic certificates that follow the IMO Guidelines for the use of electronic certificates in FAL.5/Circ.39/Rev.2. A certificate viewed on a computer on board meets the carriage requirement. The officer can still ask to verify it against the issuing Administration’s database, which is where a forged or superseded certificate usually shows. Practice on electronic certificates across all conventions is covered at electronic certificates in port State control .

Sewage treatment plant, comminuting system and holding tank

A sewage treatment plant must be of a type approved by the Administration against the IMO effluent standard that applied at its installation date:

MEPC.227(64) is the standard for all plants installed on or after 1 January 2016, not only for Baltic passenger ships; section 4.2 is the extra nutrient layer for passenger ships discharging in a special area. MEPC.284(70) defines “installed on or after 1 January 2016” and aligns the nutrient dates with the Baltic dates of 2019, 2021 and 2023.

In the engine room the officer looks for the type-approval plate and certificate, the plant running or able to be started, the disinfection unit charged, and no bypass line open around the plant to the overboard valve. A comminuting and disinfecting system is checked for working comminutor and disinfectant dosing and for storage enough to hold sewage until the ship reaches 3 nautical miles from land. A holding tank is checked against the capacity the certificate records and for a means of showing its contents; sewage holding tank sizing explains how that capacity is set.

Discharge arrangements and the standard connection

The officer reads the discharge arrangement against Regulation 11. Under Regulation 11.1.1, comminuted and disinfected sewage from an approved system may be discharged “at a distance of more than 3 nautical miles from the nearest land”, and sewage that is not comminuted or disinfected at “more than 12 nautical miles”. Sewage stored in holding tanks, or from spaces containing living animals, “shall not be discharged instantaneously but at a moderate rate when the ship is en route and proceeding at not less than 4 knots”, with the rate approved by the Administration on the basis of the IMO standard in MEPC.157(55). Under Regulation 11.1.2, effluent from an approved plant in operation may be discharged at any distance, except by a passenger ship inside a special area under Regulation 11.3, provided it “shall not produce visible floating solids nor cause discoloration of the surrounding water”.

The physical checks follow from that. The officer traces the piping from plant or tank to the overboard valve and asks how the valve is secured in port. The shore discharge flange is checked against the dimensions in Regulation 10, so that any reception facility can take the ship’s sewage. A missing or wrong flange is recorded under Paris MoU code 14404.

In the Baltic Sea special area , the only special area under Annex IV, Regulation 11.3 prohibits passenger ships from discharging sewage unless they use an approved plant meeting the MEPC.227(64) section 4.2 nutrient limits. The dates set by MEPC.275(69) are 1 June 2019 for new passenger ships, 1 June 2021 for existing ones, and 1 June 2023 for existing passenger ships en route directly to or from a port outside the special area and a port east of longitude 28°10’ E with no other special-area call. An officer in a Baltic port checks a passenger ship’s plant certificate for the section 4.2 endorsement, or for evidence that sewage went ashore.

Records: what exists and what does not

MARPOL Annex IV does not require a Sewage Record Book. That separates it from Annex I, which has the Oil Record Book , and Annex V, which has the Garbage Record Book . An officer therefore cannot record the absence of a sewage log as a breach of Annex IV.

Records still matter as evidence. Many companies keep a sewage discharge log under their safety management system, and a plant log, reception-facility receipts, and the engine-room and deck logbooks all carry positions and times. An officer comparing a logged discharge position with the chart can establish a Regulation 11 breach from those records. A full holding tank on arrival with no receipt from the last port is a question the chief engineer should be ready to answer. A draft Regulation 11A on a Sewage Record Book is in progress at the IMO, discussed under pending changes below; if adopted, it would bring sewage into the electronic record book framework the other annexes use.

Crew familiarity

Familiarity is the ground Regulation 14 names, so it is the strand most often tested by conversation rather than paperwork. The officer asks the engineer responsible to describe the system, start the plant or show how the tank level is read, state the discharge distances, explain the overboard valve’s port setting, and point to the last discharge entry. A crew that can do this in English, or through an interpreter where needed, meets the test. A.1206(34) paragraph 2.4.2 counts key crew who cannot communicate with each other as clear grounds in its own right.

A familiarity failure under Regulation 14 is often also a safety-management failure. Section 6 of the ISM Code deals with resources and personnel, including familiarization of new personnel with duties relating to protection of the environment, and SOLAS regulation IX/6.2 is the ISM control provision listed alongside Regulation 14 in A.1206(34) paragraph 1.4. Where the officer finds that the company’s procedures do not cover sewage at all, the deficiency may be recorded under ISM as well as Annex IV. The certification side of crew competence sits with the STCW Convention .

Detainable sewage deficiencies under A.1206(34)

A.1206(34) Appendix 2, the guidelines for the detention of ships, lists four detainable areas under MARPOL Annex IV:

1. absence of a valid ISPP Certificate;
2. a sewage treatment plant not approved and certified by the Administration;
3. failure of the sewage treatment plant;
4. ship’s personnel not familiar with the disposal or discharge requirements of sewage.

The list is illustrative. Appendix 2 paragraph 5 says the lists are not exhaustive, and paragraph 3.5 allows a combination of less serious deficiencies to justify detention. The officer applies the MARPOL Article 5(2) test of whether the ship can proceed to sea without presenting an unreasonable threat of harm to the marine environment, with the “timing” and “re-inspection criterion” in Appendix 2 paragraph 3.1: whether the deficiency can be put right before departure, and whether the ship would need to be re-inspected before sailing.

In practice the four items behave differently. An absent certificate on a Party ship is detainable on its face. Appendix 2 paragraph 4, however, says the absence of a convention certificate on a ship of a non-Party is not by itself a ground for detention, so there the officer judges the ship’s condition directly. A failed plant on a ship that relies on it, and has no holding capacity, cannot legally discharge anywhere within 12 nautical miles of land, which puts a passenger ship on a coastal schedule in an immediate problem. A crew-familiarity finding usually travels with one of the others.

Deficiency codes

The Paris MoU Overview of Deficiency Codes dated 1 July 2024 records the ISPP Certificate as code 01119 in the certificates group. The MARPOL Annex IV group, 144, has four codes:

A finding of crew unfamiliarity is recorded against the code the officer judges closest, often with an ISM deficiency alongside it. The code structure and how deficiencies feed targeting are covered at PSC deficiency codes .

After a detention: rectification, release, appeal and compensation

A detention under Regulation 14.2 and Article 5(2) holds the ship until the deficiencies are rectified or the port State accepts a plan that lets it sail without unreasonable threat of harm to the marine environment. A.1206(34) paragraph 1.7.4 defines detention, and Appendix 2 carries the guidelines an officer applies before ordering one.

Rectification. For a failed plant, the usual routes are repair and a functional test witnessed by the officer, or a temporary arrangement accepted by the port State and the flag State. One such arrangement is holding all sewage and delivering it ashore until the plant is repaired. The recognized organization that issued the ISPP Certificate on behalf of the flag may be called to attend, and A.1206(34) paragraph 4.1.3 requires the port State to notify it of a detention where it is responsible for the relevant certificate.

Repair-yard release. Article 5(2) lets the port State permit the ship to sail to the nearest appropriate repair yard available. A.1206(34) paragraph 3.7.3 sets out the conditions agreed with the flag State for that passage. A ship that fails to call at the agreed yard is exposed to refusal of access under the Paris MoU banning rules.

Notification. A.1206(34) paragraph 3.5.2 requires the port State to notify the flag Administration in writing, and paragraph 4.1.5 requires detention reports to the IMO under MARPOL Article 11. The flag State then reports its remedial action, through GISIS or the Appendix 17 form, under paragraph 4.2.1.

Appeal. A.1206(34) paragraph 2.3.11 recognizes the owner’s or operator’s right of appeal under the port State’s national law and says “The appeal should not cause the detention to be suspended.” Regional regimes add their own review routes; the Paris and Tokyo arrangements are described at PSC detention review .

Compensation. MARPOL Article 7(2) gives a ship unduly detained or delayed a right to compensation for loss or damage suffered. A.1206(34) paragraph 2.1.4 states the same principle in recommendatory language. Neither text sets a procedure, so the claim runs under the port State’s law.

The Procedures for Port State Control, A.1206(34)

Resolution A.1206(34), “Procedures for Port State Control, 2025”, adopted by the IMO Assembly on 3 December 2025, is the current edition of the IMO’s harmonized guidance and revokes A.1185(33). It is a recommendation: operative paragraph 2 invites Governments to apply it, and the resolution states no date of application. The binding powers it describes are in the conventions it lists in paragraph 1.4.

For sewage, the Procedures supply four things Regulation 14 lacks:

• definitions that make “clear grounds”, “detention”, “more detailed inspection” and “valid certificates” mean the same in every port (paragraph 1.7);
• officer qualifications, including the paragraph 1.9.5 requirement that an officer carrying out operational inspections be a master or chief engineer with seagoing experience, hold a recognized maritime qualification with specialized training, or be an equivalent Administration officer;
• the detention guidelines in Appendix 2, with the four Annex IV items;
• the operational-control guidance in Appendix 7, which names Regulation 14 at paragraphs 5.2.2 and 8.2.5.

Paragraph 1.8.3 adds an independence rule: port State control officers may not be employed by, or work on behalf of, recognized organizations or classification societies. The conduct expected of officers is the Code of good practice in MSC-MEPC.4/Circ.2, reproduced as Appendix 1. The 2025 edition also introduced Appendix 20, guidance on security aspects.

The lineage matters when reading an older detention record. The editions most often cited are A.1052(27) of 30 November 2011, A.1119(30), A.1138(31) of 4 December 2019, A.1155(32) of 15 December 2021, A.1185(33) of 6 December 2023, and A.1206(34). A.1052(27) still calls the sewage control provision Regulation 13; A.1138(31) and every later edition call it Regulation 14. The resolution’s structure is analysed in IMO Procedures for Port State Control .

Regional regimes: Paris MoU, Tokyo MoU and others

MARPOL gives each Party the power to inspect but does not coordinate which ships are inspected or share results. The IMO lists nine port State control regimes, eight regional memoranda of understanding and one agreement, with the United States Coast Guard running its own national regime. The regimes are described at regional port State control MoUs and in the general port State control article.

Paris MoU

The Paris MoU has 28 signatory maritime Authorities. The Russian Federation’s membership was suspended on 20 May 2022, so 27 are active. EU members also apply Directive 2009/16/EC , which gives the regime statutory force in EU ports and the EMSA-hosted THETIS information system.

The Paris MoU has targeted ships through its New Inspection Regime since 1 January 2011. Each ship carries a Ship Risk Profile built from ship type, age, flag performance, recognized-organization performance, company performance, whether the flag State has completed an IMO audit, and its own deficiency and detention history. Age is a single band: a ship over 12 years old scores one point.

The Paris MoU Annual Report 2025 records 16,474 inspections, 668 detentions and a detention rate of 4.18%. The 2025 White, Grey and Black List , built on 2023 to 2025 inspection data and valid from 1 July 2026, ranks 69 flags: 40 White, 19 Grey and 10 Black, with Cameroon last on an excess factor of 7.14. The regime issued 15 refusals of access in 2024 and 19 in 2025.

Tokyo MoU

The Tokyo MoU has 22 member Authorities across the Asia-Pacific and records inspections in APCIS . Its 2025 Annual Report records 35,546 inspections and 1,255 detentions, a detention rate of 3.53%. The most frequently recorded deficiency categories were fire safety, life-saving appliances, working and living conditions, and safety of navigation.

The Tokyo MoU no longer publishes a White, Grey and Black List. Its flag performance list valid from 1 July 2026 to 30 June 2027 ranks 66 flags as Low, Medium or High performance.

Both regimes run concentrated inspection campaigns on a single topic. The 2024 joint campaign was on crew wages and seafarers’ employment agreements; in the Paris MoU region it covered 3,863 ships. The 2026 joint campaign is on cargo securing.

Other regimes, the EU delivery duty and the United States

The other memoranda apply the same A.1206(34) baseline with their own targeting and databases. The Mediterranean MoU recorded 5,993 inspections and 196 detentions in 2024, and several Mediterranean Authorities are also Paris MoU members. Whether a given Authority enforces Annex IV depends on that State having accepted the Annex, since A.1206(34) paragraph 1.2.4 confines control to provisions in force and accepted by the port State.

The EU adds a delivery duty that operates alongside Regulation 14. Directive (EU) 2019/883 Article 7(1) requires the master of a ship calling at an EU port to deliver all waste on board to a port reception facility before leaving, in accordance with the MARPOL discharge norms. Article 2(3) includes waste covered by Annex IV in the definition of waste from ships, and Member States had to transpose the Directive by 28 June 2021. An inspector in an EU port can therefore ask about sewage delivery under national law even where Annex IV itself is satisfied. The Directive is covered at EU Port Reception Facilities Directive 2019/883 .

The United States is the main exception. The US Environmental Protection Agency states that “The United States is not a party to MARPOL Annex IV”. Sewage from vessels in US waters is regulated under section 312 of the Clean Water Act and the marine sanitation device rules in 33 CFR Part 159 , which the Coast Guard applies to foreign ships as US law. A foreign ship’s ISPP Certificate is not the document a US Coast Guard port State control examination turns on for sewage.

Survey regime and port State control compared

Annex IV runs two compliance mechanisms, and Regulation 14 is only one of them. The survey and certificate scheme in Regulations 4 to 8 is flag-State led, scheduled and condition based. Regulation 14 is port-State led, unscheduled and operation based.

The two answer different questions, which is why a ship can pass its renewal survey and be detained a month later. The surveyor checked the plant on a day it was maintained and running; the port State officer found it bypassed. The classification society acting as recognized organization sees the result in the regional databases, and recognized-organization performance is one input to the Paris MoU Ship Risk Profile. That gives class a direct interest in how its certified ships fare at port State control.

Annex IV has a third mechanism, aimed at the State rather than the ship. MEPC.246(66), in force 1 January 2016, added Chapter 6, Regulations 15 and 16, which make the III Code mandatory and subject each Party to audit under the IMO Member State Audit Scheme . An audit can examine how a State discharges its port State duties, including Regulation 14, but it never inspects a ship.

Port State control in the other MARPOL annexes

Each MARPOL annex carries its own operational control provision, with nearly identical wording and a different number. A.1206(34) paragraph 1.4 lists them all:

Both Annex III and Annex IV renumbered their control provision after first adoption, which is why older cross-annex tables carry two wrong numbers. Annex III moved from 8 to 9 when MEPC.246(66) inserted definitions as a new Regulation 1. Annex IV moved from 13 to 14 when the reception-facility rule was inserted. Annex VI control carries the largest set of detainable items in Appendix 2, covering IAPP and EIAPP certificates, the EEXI Technical File, the SEEMP, the carbon intensity Statement of Compliance and fuel sulphur.

Pending Annex IV changes: Sewage Record Book and Sewage Management Plan

The IMO is revising Annex IV, and the draft would give port State control officers a record to read. At PPR 13, held 9 to 13 February 2026, the Sub-Committee on Pollution Prevention and Response agreed in principle a draft Regulation 11A on a Sewage Record Book , with its form in a new appendix, and a draft Regulation 11B on a Sewage Management Plan. The correspondence group continues the work.

Nothing has been approved by the Marine Environment Protection Committee or adopted, so no entry-into-force date exists. Amendments to an annex enter into force through the tacit acceptance procedure in MARPOL Article 16, which runs a minimum period between adoption and entry into force. Until then Regulation 14 inspections run against the current Annex IV, with no mandatory sewage record. Operators who already keep a log under their SMS will find the transition simpler, because the officer’s familiarity questions already draw on the information a record book would hold.

An illustrative inspection sequence

The following sequence is a composite built from the A.1206(34) procedure, not a report of a specific inspection. It shows how the steps connect.

A cruise ship of 60,000 GT calls at a Paris MoU port. Its Ship Risk Profile puts it in the window for a periodic inspection. The officer checks the certificates first. The ISPP Certificate is valid, issued by a recognized organization on behalf of the flag, and records an approved sewage treatment plant installed in 2017, which places it under MEPC.227(64).

In the engine room the officer asks the second engineer to show the plant running. The plant is stopped, and a spool piece connects the raw-sewage collecting tank to the overboard line. The engineer says the plant has been off since a blower failed on the previous passage, and cannot state the distance from land at which untreated sewage may be discharged. Those are two of the A.1206(34) paragraph 2.4.2 categories, a serious deficiency in pollution-prevention equipment and crew unfamiliarity, so the officer moves to a more detailed inspection.

The ship’s own sewage log, kept under its SMS, shows two discharges on the last coastal leg. Plotted on the chart, one sits about 8 nautical miles from land, which is inside the 12-mile limit for untreated sewage under Regulation 11.1.1. The officer records:

• 14402 for the treatment plant out of service;
• a familiarity deficiency;
• an ISM deficiency, because the company’s procedures had no instruction for a plant failure.

The officer marks 14402 and the familiarity finding as detainable under the Appendix 2 Annex IV items. The suspected discharge is separately reported to the flag Administration under Article 6.

Release depends on rectification. The blower is replaced, the spool piece removed and blanked, and the plant run under the officer’s observation. The company issues an instruction to hold sewage and deliver it ashore if the plant fails again. The detention is reported to the flag Administration and the recognized organization, entered in THETIS and reported to the IMO, and it raises the ship’s risk profile for its next calls in the region.

Preparing for an Annex IV inspection

A master and chief engineer can close most Regulation 14 exposures before the officer boards. The checks follow the A.1206(34) Appendix 2 items and the familiarity test:

1. ISPP Certificate on board, in date, matching the fitted system, and, if electronic, verifiable under FAL.5/Circ.39/Rev.2.
2. Type-approval certificate for the treatment plant available, showing MEPC.2(VI), MEPC.159(55) or MEPC.227(64) as applicable, and the section 4.2 endorsement for a passenger ship trading in the Baltic.
3. Plant running, disinfection charged, no bypass or spool piece fitted around the plant.
4. Overboard valve secured in port by a method the engineers can demonstrate.
5. Standard discharge flange matching Regulation 10, with a blank and gasket.
6. Holding tank level known, with receipts for the last delivery ashore.
7. A sewage log, if the company keeps one, consistent with the deck log positions.
8. At least the engineer in charge able to state the 3-mile, 12-mile and 4-knot conditions and the Baltic rule if relevant.
9. SMS instructions covering plant failure, tank-full situations and discharge prohibitions.

A ship trading regularly to EU ports should also hold its waste delivery receipts under Directive 2019/883, and a ship trading to the United States should treat its marine sanitation device certification under 33 CFR Part 159 as a separate compliance file. Passenger ships carry the highest sewage volumes and the Baltic nutrient rule, so the cruise and passenger operations article covers how lines organize sewage handling across itineraries.

Limitations

This article covers the enforcement mechanism in Regulation 14. The equipment, connection and discharge standards it enforces are covered in the Regulation 9, Regulation 10 and Regulation 11 articles, and the survey scheme in the ISPP Certificate article.

Regional figures are those published in the Paris MoU Annual Report 2025, the Paris MoU White, Grey and Black List 2025, and the Tokyo MoU Annual Report 2025. None of these publications breaks out detentions by MARPOL Annex IV item, so the article states no sewage-specific detention rate.

The Paris MoU issues its own instructions to officers on individual conventions, and its deficiency code list changes. The codes here are from the list dated 1 July 2024. The content of Paris MoU instructions specific to Annex IV is not reproduced, because those documents are not publicly available in full.

A.1206(34) is recommendatory, and a port State applies it through national law, so procedure on appeal, compensation and repair-yard release differs between States. The draft Sewage Record Book and Sewage Management Plan were agreed in principle only, and their final content may change before adoption. United States sewage rules under 33 CFR Part 159 are summarized only to mark the boundary; they are not analysed here.

Related Articles

• MARPOL Annex IV: prevention of pollution by sewage from ships
• MARPOL Annex IV Regulation 9: sewage systems
• MARPOL Annex IV Regulation 10: standard discharge connection
• MARPOL Annex IV Regulation 11: sewage discharge
• MARPOL Annex IV Regulation 13: reception facilities for passenger ships in special areas
• MARPOL Annex IV surveys and the ISPP Certificate
• MARPOL Annex IV Baltic Sea special area for passenger ships
• MARPOL special areas
• MARPOL Annex I Regulation 11: PSC on operational requirements
• MARPOL Annex II Regulation 16: measures of control
• Port State control
• Port State control officer
• HELCOM Convention 1992
• Marine sewage and grey-water treatment systems