| (1) | Subject to the provisions of paragraphs (5) and (6) of this Regulation, oil tankers of 150 tons gross tonnage and above shall be provided with arrangements in accordance with the requirements of paragraphs (2) and (3) of this Regulation, provided that in the case of existing tankers the requirements for oil discharge monitoring and control systems and slop tank arrangements shall apply three years after the date of entry into force of the present Convention. |
(2)
| (a) | Adequate means shall be provided for cleaning the cargo tanks and transferring the dirty ballast residue and tank washings from the cargo tanks into a slop tank approved by the Administration. In existing oil tankers, any cargo tank may be designated as a slop tank. |
| (b) | In this system arrangements shall be provided to transfer the oily waste into a slop tank or combination of slop tanks in such a way that any effluent discharged into the sea will be such as to comply with the provisions of Regulation 9 of this Annex. |
| (c) | The arrangements of the slop tank or combination of slop tanks shall have a capacity necessary to retain the slop generated by tank washings, oil residues and dirty ballast residues. The total capacity of the slop tank or tanks shall not be less than 3 per cent of the oil carrying capacity of the ships, except that the Administration may accept: |
| (i) | 2 per cent for such oil tankers where the tank washing arrangements are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system; |
| (ii) | 2 per cent where segregated ballast tanks or dedicated clean ballast tanks are provided in accordance with Regulation 13 of this Annex, or where a cargo tank cleaning system using crude oil washing is fitted in accordance with Regulation 13B of this Annex. This capacity may be further reduced to 1,5 per cent for such oil tankers where the tank washing arrangements are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system; |
| (iii) | 1 per cent for combination carriers where oil cargo is only carried in tanks with smooth walls. This capacity may be further reduced to 0,8 per cent where the tank washing arrangements are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system. |
New oil tankers of 70 000 tons deadweight and above shall be provided with at least two slop tanks.
| (d) | Slop tanks shall be so designed particularly in respect of the position of inlets, outlets, baffles or weirs where fitted, so as to avoid excessive turbulence and entrainment of oil or emulsion with the water. |
(3)
| (a) | An oil discharge monitoring and control system approved by the Administration shall be fitted. In considering the design of the oil content meter to be incorporated in the system, the Administration shall have regard to the specification recommended by the Organization.1 The system shall be fitted with a recording device to provide a continuous record of the discharge in litres per nautical mile and total quantity discharged, or the oil content and rate of discharge. This record shall be identifiable as to time and date and shall be kept for at least three years. The oil discharge monitor and control system shall come into operation when there is any discharge of effluent into the sea and shall be such as will ensure that any discharge of oily mixture is automatically stopped when the instantaneous rate of discharge of oil exceeds that permitted by Regulation 9(1)(a) of this Annex. Any failure of this monitoring and control system shall stop the discharge and be noted in the Oil Record Book. A manually operated alternative method shall be provided and may be used in the event of such failure, but the defective unit shall be made operable as soon as possible. The port state authority may allow the tanker with a defective unit to undertake one ballast voyage before proceeding to a repair port. The oil discharge monitoring and control system shall be designed and installed in compliance with the Revised Guidelines and Specifications for Oil Discharge Monitoring and Control Systems for Oil Tankers developed by the Organization.2 Administrations may accept such specific arrangements as detailed in the Guidelines and Specifications. |
| (b) | Effective oil/water interface detectors approved by the Administration shall be provided for a rapid and accurate determination of the oil/water interface in slop tanks and shall be available for use 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. |
| (c) | Instructions as to the operation of the system shall be in accordance with an operational manual approved by the Administration. They shall cover manual as well as automatic operations and shall be intended to ensure that at no time shall oil be discharged except in compliance with the conditions specified in Regulation 9 of this Annex.3 |
| (4) | The requirements of paragraphs (1), (2) and (3) of this Regulation shall not apply to oil tankers of less than 150 tons gross tonnage, for which the control of discharge of oil under Regulation 9 of this Annex shall be effected by the retention of oil on board with subsequent discharge of all contaminated washings to reception facilities. The total quantity of oil and water used for washing and returned to a storage 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 allowed to be discharged into the sea is effectively monitored to ensure that the provisions of Regulation 9 of this Annex are complied with. |
(5)
| (a) | The Administration may waive the requirements of paragraphs (1), (2) and (3) of this Regulation for any oil tanker which engages exclusively on voyages both of 72 hours or less in duration and within 50 miles from the nearest land, provided that the oil tanker is engaged exclusively in trades between ports or terminals within a State Party to the present Convention. Any such waiver shall be subject to the requirement that the oil tanker shall retain on board all oily mixtures for subsequent discharge to reception facilities and to the determination by the Administration that facilities available to receive such oily mixtures are adequate. |
| (b) | The Administration may waive the requirements of paragraph (3) of this Regulation for oil tankers other than those referred to in subparagraph (a) of this paragraph in cases where— |
| (i) | the tanker is an existing oil tanker of 40 000 tons deadweight or above, as referred to in Regulation 13C(1) of this Annex, engaged in specific trades, and the conditions specified in Regulation 13C(2) are complied with; or |
| (ii) | the tanker is engaged exclusively in one or more of the following categories of voyages: |
| (1) | voyages within special areas; or |
| (2) | voyages within 50 miles from the nearest land outside special areas where the tanker is engaged in: |
| (aa) | trades between ports or terminals of a State Party to the present Convention; or |
| (bb) | restricted voyages as determined by the Administration, and of 72 hours or less in duration: Provided that all of the following conditions are complied with: |
| (3) | all oily mixtures are retained on board for subsequent discharge to reception facilities; |
| (4) | for voyages specified in subparagraph (b)(ii)(2) of this paragraph, the Administration has determined that adequate reception facilities are available to receive such oily mixtures in those oil loading ports or terminals the tanker calls at; |
| (5) | the International Oil Pollution Prevention Certificate, when required 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)(1) and (b)(ii)(2)(bb) of this paragraph; and |
| (6) | the quantity, time and port of the discharge are recorded in the Oil Record Book. |
| (6) | Where in the view of the Organization equipment required by Regulation 9 (1)(a)(vi) of this Annex and specified in subparagraph (3)(a) of this Regulation is not obtainable for the monitoring of discharge of light refined products (white oils), the Administration may waive compliance with such requirement, provided that discharge shall be permitted only in compliance with procedures established by the Organization which shall satisfy the conditions of Regulation 9(1)(a) of this Annex except the obligation to have an oil discharge monitoring and control system in operation. The Organization shall review the availability of equipment at intervals not exceeding twelve months. |
| (7) | The requirements of paragraphs (1), (2) and (3) of this Regulation shall not apply to oil tankers carrying asphalt or other products subject to the provisions of this Annex, which through their physical properties inhibit elective product/water separation and monitoring, for which the control of discharge under Regulation 9 of this Annex shall be effected by the retention of residues on board with discharge of all contaminated washings to reception facilities. |
| 1 | Reference is made to the Recommendation on International Performance and Test Specifications for Oily Water Separating Equipment and Oil Content Meters adopted by the Organization by Resolution A.233 (VII). |
| 2 | Reference is made to the Revised Guidelines and Specifications for Oil Discharge Monitoring and Control Systems for Oil Tankers adopted by the Organization by resolution A.586(14). |
| 3 | Reference is made to "Clean Seas Guide for Oil Tankers", published by the International Chamber of Shipping and the Oil Companies International Marine Forum. |
