Sewage discharge conditions and the surveys and validity of the International Sewage Pollution Prevention Certificate (MARPOL Annex IV Regulations 2, 4, 8 and 11)

MARPOL Annex IV reads along two axes. One is the certificate. Which ships need an International Sewage Pollution Prevention Certificate (ISPP), what kinds of survey there are, and how the validity is counted. The other is discharge. The distance, speed and equipment conditions under which sewage may be discharged into the sea.

The base text is the revised Annex IV adopted by resolution MEPC.115(51), in force from 1 August 2005. Regulation 11, the discharge provision, was replaced in full by MEPC.200(62), in force from 1 January 2013. This article reads Regulation 11 as replaced.

The same resolution designated the Baltic Sea as a special area. That provision reaches only passenger ships inside the special area and is not a worldwide obligation. Every other ship follows regulation 11.1 in whichever sea it is.

The Annex applies to ships on international voyages, at 400 gross tonnage or more than 15 persons

1 The provisions of this Annex shall apply to the following ships engaged in international voyages: .1 new ships of 400 gross tonnage and above; and .2 new ships of less than 400 gross tonnage which are certified to carry more than 15 persons; and .3 existing ships of 400 gross tonnage and above, five years after the date of entry into force of this Annex; and .4 existing ships of less than 400 gross tonnage which are certified to carry more than 15 persons, five years after the date of entry into force of this Annex.

One condition comes first. The ship has to be engaged in international voyages. Regulation 1.6 defines an international voyage as one from a country to which the Convention applies to a port outside that country. Then comes 400 gross tonnage, or a certified capacity of more than 15 persons. Where the Annex V management plan reads 15 or more, this one reads more than 15. A ship certified for 15 persons is caught by the Annex V management plan and not by Annex IV.

The Person of regulation 1.7 counts crew and passengers together. The five-year grace period for existing ships ran from the 2005 entry into force and has already passed.

The certificate rests on three kinds of survey, initial, renewal and additional

.1 An initial survey before the ship is put in service or before the Certificate required under regulation 5 of this Annex is issued for the first time, which shall include a complete survey of its structure, equipment, systems, fittings, arrangements and material in so far as the ship is covered by this Annex. This survey shall be such as to ensure that the structure, equipment, systems, fittings, arrangements and material fully comply with the applicable requirements of this Annex. .2 A renewal survey at intervals specified by the Administration, but not exceeding five years, except where regulation 8.2, 8.5, 8.6 or 8.7 of this Annex is applicable. The renewal survey shall be such as to ensure that the structure, equipment, systems, fittings, arrangements and material fully comply with applicable requirements of this Annex. .3 An additional survey either general or partial, according to the circumstances, shall be made after a repair resulting from investigations prescribed in paragraph 4 of this regulation, or whenever any important repairs or renewals are made. The survey shall be such as to ensure that the necessary repairs or renewals have been effectively made, that the material and workmanship of such repairs or renewals are in all respects satisfactory and that the ship complies in all respects with the requirements of this Annex.

Unlike the IAPP Certificate under Annex VI, there is no annual survey and no intermediate survey. There are only three surveys. The initial survey before entry into service or before the first certificate, the renewal survey at the interval the Administration sets, and the additional survey after repairs or renewals. The ceiling on the renewal interval is five years.

Surveys are carried out by officers of the Administration, which may entrust them to nominated surveyors or recognized organizations (regulation 4.3). After a survey, no change may be made to the structure or equipment covered by it without the sanction of the Administration, the only exception being direct replacement (regulation 4.8). Where an accident or a defect occurs, the master or owner reports at once to those responsible for issuing the certificate (regulation 4.9).

Validity is capped at five years and the timing of the renewal survey fixes the start date

1 An International Sewage Pollution Prevention Certificate shall be issued for a period specified by the Administration which shall not exceed five years. 2.1 Notwithstanding the requirements of paragraph 1 of this regulation, when the renewal survey is completed within three months before the expiry date of the existing Certificate, the new Certificate shall be valid from the date of completion of the renewal survey to a date not exceeding five years from the date of expiry of the existing Certificate. .2 When the renewal survey is completed after the expiry date of the existing Certificate, the new Certificate shall be valid from the date of completion of the renewal survey to a date not exceeding five years from the date of expiry of the existing Certificate. .3 When the renewal survey is completed more than three months before the expiry date of the existing Certificate, the new Certificate shall be valid from the date of completion of the renewal survey to a date not exceeding five years from the date of completion of the renewal survey.

The three cases differ in where the five years of the new certificate are counted from. Complete the renewal survey within three months before expiry and the five years run from the existing expiry date. Complete it after expiry and they still run from the existing expiry date. Complete it more than three months before expiry and they run from the survey completion date, so that much validity is lost.

Renewal survey completed	New certificate valid from	Ceiling on the new expiry date
Within three months before expiry	Survey completion date	Existing expiry date plus five years
After expiry	Survey completion date	Existing expiry date plus five years
More than three months before expiry	Survey completion date	Survey completion date plus five years

Extensions come in three forms. Where the renewal survey is complete but the new certificate cannot be placed on board, the existing certificate may be endorsed and accepted for up to five months from expiry (8.4). Where the ship is not in the port where it is to be surveyed, validity may be extended for up to three months solely to let the ship reach that port, and on arrival the ship may not leave without a new certificate (8.5). A ship on short voyages may be granted a period of grace of up to one month (8.6). In every case the five years of the new certificate run from the expiry date before the extension.

8 A Certificate issued under regulation 5 or 6 of this Annex shall cease to be valid in either of the following cases: .1 if the relevant surveys are not completed within the periods specified under regulation 4.1 of this Annex; or .2 upon transfer of the ship to the flag of another State. A new Certificate shall only be issued when the Government issuing the new Certificate is fully satisfied that the ship is in compliance with the requirements of regulations 4.7 and 4.8 of this Annex. In the case of a transfer between Parties, if requested within 3 months after the transfer has taken place, the Government of the Party whose flag the ship was formerly entitled to fly shall, as soon as possible, transmit to the Administration copies of the Certificate carried by the ship before the transfer and, if available, copies of the relevant survey reports.

There are two grounds for loss of validity. Surveys not completed within their periods, and a change of flag. After a transfer of flag the new certificate is issued only once the new flag State is satisfied that regulations 4.7 and 4.8 are met. The former flag State sends copies of the old certificate and survey reports on request.

The equipment is one of a treatment plant, a comminuting and disinfecting system or a holding tank

1 Every ship which, in accordance with regulation 2, is required to comply with the provisions of this Annex shall be equipped with one of the following sewage systems: .1 a sewage treatment plant which shall be of a type approved by the Administration, taking into account the standards and test methods developed by the Organization, or .2 a sewage comminuting and disinfecting system approved by the Administration. Such system shall be fitted with facilities to the satisfaction of the Administration, for the temporary storage of sewage when the ship is less than 3 nautical miles from the nearest land, or .3 a holding tank of the capacity to the satisfaction of the Administration for the retention of all sewage, having regard to the operation of the ship, the number of persons on board and other relevant factors. The holding tank shall be constructed to the satisfaction of the Administration and shall have a means to indicate visually the amount of its contents.

Which equipment is fitted decides which line of the discharge conditions below the ship can use. A comminuting and disinfecting system is approved only with temporary storage for use inside 3 nautical miles. A holding tank has to be sized for the ship’s operation and the number of persons on board, and has to show its contents visually. Regulation 10 sets the flange dimensions of the standard discharge connection for the pipes of reception facilities.

The discharge conditions are in Regulation 11 as rewritten by MEPC.200(62)

1 Subject to the provisions of regulation 3 of this Annex, the discharge of sewage into the sea is prohibited, except when: .1 the ship is discharging comminuted and disinfected sewage using a system approved by the Administration in accordance with regulation 9.1.2 of this Annex at a distance of more than 3 nautical miles from the nearest land, or sewage which is not comminuted or disinfected at a distance of more than 12 nautical miles from the nearest land, provided that, in any case, the sewage that has been stored in holding tanks, or sewage originating 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; the rate of discharge shall be approved by the Administration based upon standards developed by the Organization; or .2 the ship has in operation an approved sewage treatment plant which has been certified by the Administration to meet the operational requirements referred to in regulation 9.1.1 of this Annex, and the effluent shall not produce visible floating solids nor cause discoloration of the surrounding water.

There are three routes. Comminuted and disinfected sewage beyond 3 nautical miles, untreated sewage beyond 12. In either case, sewage stored in holding tanks or coming from spaces with living animals may not be released all at once. It goes out at a rate the Administration has approved, with the ship en route at not less than 4 knots. With an approved treatment plant in operation there is no distance condition, but the effluent may not produce visible floating solids or discolour the surrounding water.

Set against the 2005 text, two things changed. Sewage from spaces with living animals came under the same rate condition as holding tank sewage. On the treatment plant side, the sub-item requiring the test results to be laid down in the certificate was dropped, leaving only the effluent condition. Regulation 11.2 lets a ship follow less stringent requirements a coastal State imposes in waters under its jurisdiction.

In a special area only passenger ships ride a different line

3 Subject to the provisions of regulation 3 of this Annex, the discharge of sewage from a passenger ship within a special area shall be prohibited: a) for new passenger ships on, or after 1 January 2016, subject to paragraph 2 of regulation 12bis; and b) for existing passenger ships on, or after 1 January 2018, subject to paragraph 2 of regulation 12bis, except when the following conditions are satisfied: the ship has in operation an approved sewage treatment plant which has been certified by the Administration to meet the operational requirements referred to in regulation 9.2.1 of this Annex, and the effluent shall not produce visible floating solids nor cause discoloration of the surrounding water.

MEPC.200(62) added a definition of special area (5bis) to regulation 1 and made the Baltic Sea the first one. A passenger ship is a ship carrying more than 12 passengers (7ter). A passenger ship inside a special area may not discharge sewage unless a treatment plant under regulation 9.2.1 is in operation. The routes of comminuting and disinfecting, or of discharging beyond 12 nautical miles, are closed.

The two dates in the text carry the words subject to paragraph 2 of regulation 12bis.

2 The Government of each Party concerned shall notify the Organization of the measures taken pursuant to paragraph 1 of this regulation. Upon receipt of sufficient notifications in accordance with paragraph 1 of this regulation, the Organization shall establish a date from which the requirements of regulation 11.3 in respect of the area in question shall take effect. The Organization shall notify all Parties of the date so established no less than 12 months in advance of that date. Until the date so established, ships while navigating in the special area shall comply with the requirements of regulation 11.1 of this Annex.

So the actual effective date of regulation 11.3 is set separately by the Organization after it receives the coastal Parties’ notifications on reception facilities. Until that date, ships inside the special area follow regulation 11.1. This article covers the text of resolution MEPC.200(62) only. The date actually set for the Baltic Sea has to be confirmed in the later resolutions.

Worth confirming

The exceptions in regulation 3 (securing safety, discharge resulting from damage) apply to Regulation 11 only and do not touch the certificate requirements. Regulation 11.4 requires that where sewage is mixed with wastes covered by other Annexes, the requirements of those Annexes are met as well. MEPC.200(62) also added fields to the certificate form for the type of ship and the certification standard of the treatment plant. The effluent standards for treatment plants are set by separate resolutions of the Organization and sit outside this article.

You can consult the cited source documents

These links lead to the official publishers of the documents discussed here. Match the edition and provisions cited in the article, and check subsequent amendments and flag-state implementation before applying them.

• IMO · MEPC.115(51)
• IMO · MEPC.200(62)

Continue with the related operational guidance

• IAPP Certificate survey types, endorsements and validity by renewal timing
• Garbage discharge conditions at sea and how special areas differ (MARPOL Annex V Regulations 3, 4 and 6)