Regulation 13 - Control of discharges of residues of Noxious Liquid Substances
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Statutory Documents - IMO Publications and Documents - International Conventions - MARPOL - International Convention for the Prevention of Pollution from Ships - Annex II of MARPOL 73/78Regulations for the Control of Pollution by Noxious Liquid Substances in Bulk - Chapter 5 - Operational Discharges of Residues of Noxious Liquid Substances - Regulation 13 - Control of discharges of residues of Noxious Liquid Substances

Regulation 13 - Control of discharges of residues of Noxious Liquid Substances

 Subject to the provisions of regulation 3 of this Annex the control of discharges of residues of Noxious Liquid Substances or ballast water, tank washings or other mixtures containing such substances shall be in compliance with the following requirements.

  1 Discharge provisions

  • 1.1 The discharge into the sea of residues of substances assigned to Category X, Y or Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances shall be prohibited unless such discharges are made in full compliance with the applicable operational requirements contained in this Annex.

  • 1.2 Before any prewash or discharge procedure is carried out in accordance with this regulation, the relevant tank shall be emptied to the maximum extent in accordance with the procedures prescribed in the Manual.

  • 1.3 The carriage of substances which have not been categorized, provisionally assessed or evaluated as referred to in regulation 6 of this Annex or of ballast water, tank washings or other mixtures containing such residues shall be prohibited along with any consequential discharge of such substances into the sea.

  2 Discharge standards

  • 2.1 Where the provisions in this regulation allow the discharge into the sea of residues of substances in Category X, Y or Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances the following discharge standards shall apply:

    • .1 the ship is proceeding en route at a speed of at least 7 knots in the case of self-propelled ships or at least 4 knots in the case of ships which are not self-propelled;

    • .2 the discharge is made below the waterline through the underwater discharge outlet(s) not exceeding the maximum rate for which the underwater discharge outlet(s) is (are) designed; and

    • .3 the discharge is made at a distance of not less than 12 nautical miles from the nearest land in a depth of water of not less than 25 metres.

  • 2.2 For ships constructed before 1 January 2007 the discharge into the sea of residues of substances in Category Z or of those provisionally assessed as such or ballast water, tank washings or other mixtures containing such substances below the waterline is not mandatory.

  • 2.3 The Administration may waive the requirements of paragraph 2.1.3 for substances in Category Z, regarding the distance of not less than 12 nautical miles from the nearest land for ships solely engaged in voyages within waters subject to the sovereignty or jurisdiction of the State the flag, of which, the ship is entitled to fly. In addition, the Administration may waive the same requirement regarding the discharge distance of not less than 12 nautical miles from the nearest land for a particular ship entitled to fly the flag of their State, when engaged in voyages within waters subject to the sovereignty or jurisdiction of one adjacent state after the establishment of an agreement, in writing, of a waiver between the two coastal States involved provided that no third party will be affected. Information on such agreement shall be communicated to the Organization within 30 days for further circulation to the Parties to the Convention for their information and appropriate action if any.

  3 Ventilation of cargo residues

Ventilation procedures approved by the Administration may be used to remove cargo residues from a tank. Such procedures shall be in accordance with appendix 7 of this Annex. Any water subsequently introduced into the tank shall be regarded as clean and shall not be subject to the discharge requirements in this Annex.

  4 Exemption for a prewash

On request of the ship’s master an exemption for a prewash may be granted by the Government of the receiving Party, where it is satisfied that:

  • .1 the unloaded tank is to be reloaded with the same substance or another substance compatible with the previous one and that the tank will not be washed or ballasted prior to loading; or

  • .2 the unloaded tank is neither washed nor ballasted at sea. The prewash in accordance with the applicable paragraph of this regulation shall be carried out at another port provided that it has been confirmed in writing that a reception facility at that port is available and is adequate for such a purpose; or

  • .3 the cargo residues will be removed by a ventilation procedure approved by the Administration in accordance with appendix 7 of this Annex.

  5 The use of cleaning agents or additives

  • 5.1 When a washing medium other than water, such as mineral oil or chlorinated solvent, is used instead of water to wash a tank, its discharge shall be governed by the provisions of either Annex I or Annex II, which would apply to the medium had it been carried as cargo. Tank washing procedures involving the use of such a medium shall be set out in the Manual and be approved by the Administration.

  • 5.2 When small amounts of cleaning additives (detergent products) are added to water in order to facilitate tank washing, no additives containing Pollution Category X components shall be used except those components that are readily biodegradable and present in a total concentration of less than 10% of the cleaning additive. No restrictions additional to those applicable to the tank due to the previous cargo shall apply.

  6 Discharge of residues of Category X

  • 6.1 Subject to the provision of paragraph 1, the following provisions shall apply:

    • .1 A tank from which a substance in Category X has been unloaded, shall be prewashed before the ship leaves the port of unloading. The resulting residues shall be discharged to a reception facility until the concentration of the substance in the effluent to such facility, as indicated by analyses of samples of the effluent taken by the surveyor, is at or below 0.1% by weight. When the required concentration level has been achieved, remaining tank washings shall continue to be discharged to the reception facility until the tank is empty. Appropriate entries of these operations shall be made in the Cargo Record Book and endorsed by the surveyor referred to in regulation 16.1.

    • .2 Any water subsequently introduced into the tank may be discharged into the sea in accordance with the discharge standards in regulation 13.2.

    • .3 Where the Government of the receiving party is satisfied that it is impracticable to measure the concentration of the substance in the effluent without causing undue delay to the ship, that Party may accept an alternative procedure as being equivalent to obtain the required concentration in regulation 13.6.1.1 provided that:

      • .1 the tank is prewashed in accordance with a procedure approved by the Administration in compliance with appendix 6 of this Annex; and

      • .2 appropriate entries shall be made in the Cargo Record Book and endorsed by the surveyor referred to in regulation 16.1.

  7 Discharge of residues of Category Y and Z

  • 7.1 Subject to the provision of paragraph 1, the following provisions shall apply:

    • .1 With respect to the residue discharge procedures for substances in Category Y or Z the discharge standards in regulation 13.2 shall apply.

    • .2 If the unloading of a substance of Category Y or Z is not carried out in accordance with the Manual, a prewash shall be carried out before the ship leaves the port of unloading, unless alternative measures are taken to the satisfaction of the surveyor referred to in regulation 16. 1 of this Annex to remove the cargo residues from the ship to quantities specified in this Annex. The resulting tank washings of the prewash shall be discharged to a reception facility at the port of unloading or another port with a suitable reception facility provided that it has been confirmed in writing that a reception facility at that port is available and is adequate for such a purpose.

    • .3 For High-Viscosity or Solidifying Substances in Category Y the following shall apply:

      • .3.1 a prewash procedure as specified in appendix 6 shall be applied;

      • .3.2 the residue/water mixture generated during the prewash shall be discharged to a reception facility until the tank is empty; and

      • .3.3 any water subsequently introduced into the tank may be discharged into the sea in accordance with the discharge standards in regulation 13.2.

    • .4 For substances assigned to category Y that are persistent floaters with a viscosity equal to or greater than 50 mPa·s at 20ºC and/or with a melting point equal to or greater than 0ºC, as identified by '16.2.7' in column 'o' of chapter 17 of the IBC Code, the following shall apply in the areas in paragraph 9:

      • .1 a prewash procedure as specified in appendix VI to this annex shall be applied;

      • .2 the residue/water mixture generated during the prewash shall be discharged to a reception facility at the port of unloading until the tank is empty; and

      • .3 any water subsequently introduced into the tank may be discharged into the sea in accordance with the discharge standards in regulation 13.2.

  • 7.2 Operational requirements for ballasting and deballasting

    • 7.2.1 After unloading, and, if required, after a prewash, a cargo tank may be ballasted. Procedures for the discharge of such ballast are set out in regulation 13.2.

    • 7.2.2 Ballast introduced into a cargo tank which has been washed to such an extent that the ballast contains less than 1 ppm of the substance previously carried, may be discharged into the sea without regard to the discharge rate, ship’s speed and discharge outlet location, provided that the ship is not less than 12 miles from the nearest land and in water that is not less than 25 metres deep. The required degree of cleanliness has been achieved when a prewash as specified in appendix 6 has been carried out and the tank has been subsequently washed with a complete cycle of the cleaning machine for ships built before 1 July 1994 or with a water quantity not less than that calculated with k=1.0.

    • 7.2.3 The discharge into the sea of clean or segregated ballast shall not be subject to the requirements of this Annex.

  8 Discharges in the Antarctic Area

  • 8.1 Antarctic Area means the sea area south of latitude 60°S.

  • 8.2 In the Antarctic area any discharge into the sea of Noxious Liquid Substances or mixtures containing such substances is prohibited.

  9 Areas to which regulation 13.7.1.4 applies

9.1 the North West European waters include the North Sea and its approaches, the Irish Sea and its approaches, the Celtic Sea, the English Channel and its approaches and part of the North East Atlantic immediately to the west of Ireland. The area is bounded by lines joining the following points:

  • 48°27' N on the French coast

    48°27' N; 006°25' W

    49°52' N; 007°44' W

    50°30' N; 012° W

    56°30' N; 012° W

    62° N; 003° W

    62° N on the Norwegian coast

    57°44.8' N on the Danish and Swedish coasts

9.2 the Baltic Sea area means the Baltic Sea proper with the Gulf of Bothnia, the Gulf of Finland and the entrance to the Baltic Sea bounded by the parallel of the Skaw in the Skagerrak at 57°44.8' N;

9.3 the Western European waters is an area that covers the United Kingdom, Ireland, Belgium, France, Spain and Portugal, from the Shetland Islands in the North to Cape S. Vicente in the South, and the English Channel and its approaches. The area is bounded by lines joining the following points:

  • 58°30' N on the UK coast

    58°30' N; 000° W

    62° N; 000° W

    62° N; 003° W

    56°30' N; 012° W

    54°40'40.9'' N; 015° W

    50°56'45.3'' N; 015° W

    48°27' N; 006°25' W

    48°27' N; 008° W

    44°52' N; 003°10' W

    44°52' N; 010° W

    44°14' N; 011°34' W

    42°55' N; 012°18' W

    41°50' N; 011°34' W

    37°00' N; 009°49' W

    36°20' N; 009°00' W

    36°20' N; 007°47' W

    37°10' N; 007°25' W

    51°22'25" N; 003°21'52.5" E

    52°12' N; on the UK east coast

    52°10.3' N; 006°21.8' W

    52°01.52' N; 005°04.18' W

    54°51.43' N; 005°08.47' W

    54°40.39' N; 005°34.34' W

9.4 the Norwegian Sea is bounded by lines joining the following points:

  • 69°47.6904' N; 030°49.059' E

    69°58.758' N; 031°6.2598' E

    70°8.625' N; 031°35.1354' E

    70°16.4826' N; 032°4.3836' E

    73°23.0652' N; 036°28.5732' E

    73°35.6586' N; 035°27.3378' E

    74°2.9748' N; 033°17.8596' E

    74°20.7084' N; 030°33.5052' E

    74°29.7972' N; 026°28.1808' E

    74°24.2448' N; 022°55.0272' E

    74°13.7226' N; 020°15.9762' E

    73°35.439' N; 016°36.4974' E

    73°14.8254' N; 014°9.4266' E

    72°42.54' N; 011°42.1392' E

    71°58.2' N; 009°54.96' E

    71°37.5612' N; 008°43.8222' E

    70°43.161' N; 006°36.0672' E

    69°36.624' N; 004°47.322' E

    68°58.3164' N; 003°51.2154' E

    68°14.9892' N; 003°17.0322' E

    67°25.7982' N; 003°10.2078' E

    66°49.7292' N; 003°25.1304' E

    66°25.9344' N; 003°17.1102' E

    65°22.7214' N; 001°24.5928' E

    64°25.9692' N; 000°29.3214' W

    63°53.2242' N; 000°29.442' W

    62°53.4654' N; 000°38.355' E

    62° N; 001°22.2498' E

    62° N; 004°52.3464' E


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