The Merchant Shipping (Prevention of Oil Pollution) Regulations 1996

Retention of oil on board

15.—(1) Subject to the provisions of paragraphs (5) and (6), oil tankers of 150 GT and above shall comply with the requirements of paragraphs (2) and (3).

(2) (a) Adequate means shall be provided for cleaning the cargo tanks and transferring the dirty ballast residues and tank washings from the cargo tanks into a slop tank. In existing oil tankers, any cargo tank may be designated as a slop tank.

(b) Arrangements shall be provided to transfer the oil waste into a slop tank or combination of slop tanks in such a way that any effluent discharges into the sea will be such as to comply with regulation 13.

(c) The slop tank or combination of slop tanks provided shall have sufficient capacity to retain the slops generated by tank washings, oil residues and dirty ballast residues; and that capacity shall be not less than 3 per cent of the cargo oil carrying capacity of the ship unless—

(i) segregated ballast tanks or dedicated clean ballast tanks are provided in accordance with regulation 18, or a cargo tank cleaning system using crude oil washing, in accordance with regulation 21. In that event the total capacity of the slop tank or tanks may be reduced to 2 per cent of the oil carrying capacity of the ship;

(ii) in the case of combination carriers, the oil cargo is carried in tanks with smooth walls, when the said total capacity may be reduced to 1 per cent of the oil carrying capacity of the ship;

• Provided that, where the tank washing arrangements are such that, once the slop tank or tanks are charged with washing water, this water is sufficient for the tank washing and, where applicable, for providing the driving fluid for the pumps (including eductors) without the introdution of additional water into the system, the above figures of 3 per cent, 2 per cent and 1 per cent may be reduced to 2 per cent, 1.5 per cent and 0.8 per cent respectively.

  (d)

  Slop tanks shall be so designed, particularly as regards the position of inlets, outlets, baffles or weirs (where fitted), as to avoid excessive turbulence and entrainment of oil or emulsion with water.

  (e)

  New oil tankers of 70,000 tons deadweight and above shall be provided with at least two slop tanks.

(3) (a) An oil discharge monitoring and control system of an approved design shall be fitted. It shall be designed and installed in accordance with the Guidelines and Specification for Oil Discharge and Control Systems for Oil Tankers.

(b) Any such system shall be fitted with a recording device to provide, unless otherwise required by the Guidelines and Specifications referred to in subparagraph (a) a continuous record of the discharge of oil in litres per mile and the total quantity of oil discharged or, in lieu of the total quantity of oil discharged, the oil content and rate of discharge of the effluent. The record shall be identifiable as to the time and date and be kept for at least three years.

(c) The system shall be brought into operation when there is a discharge of effluent into the sea and shall be such as to ensure that any discharge of oily mixture is, unless otherwise permitted by the Guidelines and Specifications referred to in subparagraph (a), automatically stopped when the instantaneous rate of discharge of oil exceeds 30 litres per mile.

(d) On any failure of the system the discharge shall be stopped and the failure noted in the Oil Record Book. A manually operated alternative system shall be provided and may be used in the event of such a failure, but the defective unit shall be made operable as soon as possible. If a tanker with a defective unit is within the United Kingdom or the territorial waters thereof, the Secretary of State may allow the tanker to undertake one ballast voyage before proceeding to a repair port.

(e) Effective oil/water interface detectors, of a design approved in accordance with the Specifications for Oil/Water Interface Detectors, shall be provided for the rapid and accurate determination of the oil/water interface in slop tanks and in other tanks where the separation of oil and water is effected and from which it is intended to discharge effluent direct to the sea.

(f) Approved instruction manuals on the operation and maintenance of the various components comprising the oil discharge monitoring and control system shall be provided. These manuals shall contain information on manual as well as automatic operation and shall be so drawn up as to ensure that at no time will oil be discharged except in compliance with the conditions specified in regulation 13.

(4) Oil tankers of less than 150 GT pursuant to regulation 13 shall retain oil and all contaminated washings on board for subsequent discharge to reception facilities. The total quantity of oil and water used for washing and returned to a storage or slop tank shall be recorded in the Oil Record Book. This total quantity shall be discharged to reception facilities unless adequate arrangements are made to ensure that any effluent which is discharged into the sea is effectively monitored to ensure that the provisions of regulation 13 are complied with.

(5) (a) Paragraphs (1), (2) and (3) shall not apply to any oil tanker which is engaged exclusively on voyages of 72 hours or less in duration and within 50 miles of the nearest land, provided that—

(i) the oil tanker is engaged exclusively in trade between ports or terminals within the United Kingdom;

(ii) the oil tanker retains on board all oily-mixtures for subsequent discharge to reception facilities;

(iii) the Secretary of State has determined that adequate facilities are available to receive such oily mixtures.

(b) The requirements of paragraph (3) shall not apply to any oil tanker where—

(i) the tanker is an existing oil tanker of 40,000 deadweight tons or above, engaged in specific trades, in accordance with regulations 22(1) and complying with the conditions specified in regulation 22(2); or

(ii) subject to subparagraph (b)(iii), the tanker is engaged exclusively on voyages—

(aa) within special areas; or

(bb) within 50 miles from the nearest land outside special areas and—

(A) trading between ports and terminals within the United Kingdom; or

(B) on restricted voyages of 72 hours or less in duration;

(iii) tankers to which subparagraph (b)(ii) applies shall comply with the following requirements—

(aa) all oily mixtures are retained on board for subsequent discharge to reception facilities;

(bb) for voyages specified in subparagraph (b)(ii)(bb) adequate reception facilities are available to receive such oily mixtures in those oil loading ports or terminals the tanker calls at;

(cc) the IOPP or UKOPP Certificate is endorsed to the effect that the ship is exclusively engaged in one or more of the categories of voyages specified in subparagraphs (b)(ii)(aa) and (b)(ii)(bb) above; and

(dd) the relevant entries are recorded in the Oil Record Book.

(6) Paragraphs (1), (2) and (3) shall not apply to oil tankers carrying asphalt or other products subject to the provisions of these Regulations which, through their physical properties, inhibit effective product/water separation and monitoring: in such cases the requirements of regulation 13 shall be satisfied by the retention of residues on board and the discharge of all contaminated washings to reception facilities.