The Merchant Shipping (Prevention of Oil Pollution) Regulations 1996

Pumping, piping and discharge arrangements of oil tankers

26.—(1) In every oil tanker, a discharge manifold for the discharge of dirty ballast water or oil contaminated water to reception facilities shall be located on the open deck on both sides of the ship.

(2) In every oil tanker, pipelines for any discharge to the sea of ballast or oil contaminated water from cargo tank areas which may be permitted under regulations 12, 13 or 16 shall be led to the open deck or to the ship’s side above the waterline in the deepest ballast condition, or, subject to the approval of the Marine Safety Agency, below the waterline—

(a) to enable such discharges below the waterline as are permitted by paragraph (6) to be made; and

(b) where the discharge outlet is located above the departure ballast waterline but not above the waterline in the deepest ballast condition, if so located before 1st January 1981.

(3) In new oil tankers, means shall be provided for stopping the discharge into the sea of ballast water or oil contaminated water from cargo tank areas, other than those discharges below the waterline permitted under paragraph (6), from a position on the upper deck or above, and so located that the manifold referred to in paragraph (1) and the discharge to the sea from the pipe lines referred to in paragraph (2) may be visually observed. The means for stopping the discharge may be situated elsewhere than at the observation position if an effective communication system, such as a telephone or radio system, is provided between the observation position and the discharge control position.

(4) Every new oil tanker required to be provided with segregated ballast tanks or fitted with a crude oil washing system shall comply with the following requirements—

(a) it shall be equipped with oil piping so designed and installed that oil retention in the lines is minimised;

(b) means shall be provided to drain all cargo pumps and all oil lines at the completion of cargo discharge where necessary by connection to a stripping device, so designed that the line and pump drainings shall be capable of being discharged both ashore and to a cargo tank or a slop tank. For discharge ashore a special small diameter line shall be provided and connected outboard of the deck manifold valves, both port and starboard.

(5) Every existing crude oil tanker required to be provided with segregated ballast tanks, or to be fitted with a crude oil washing system, or to operate with dedicated clean ballast tanks shall comply with the provisions of paragraph (4)(b).

(6) Ballast water or oil contaminated water from the cargo tank areas of any oil tanker shall be discharged only above the waterline, except that—

(a) segregated ballast and clean ballast may be discharged below the waterline—

(i) in ports or at offshore terminals; or

(ii) at sea by gravity,

provided that the surface of the ballast water has been examined immediately before the discharge to ensure that no contamination with oil has taken place;

(b) existing oil tankers which, without modification, are not capable of discharging segregated ballast above the waterline may discharge segregated ballast below the waterline at sea, provided that the surface of the ballast water has been examined immediately before the discharge to ensure that no contamination with oil has taken place.

(c) existing oil tankers operating with dedicated clean ballast tanks which without modification are not capable of discharging ballast water from the dedicated clean ballast tanks above the waterline, may discharge this ballast below the waterline provided that the discharge of the ballast water is supervised with the aid of an oil content meter as provided for in regulation 20(3).

(d) dirty ballast water or oil contaminated water from tanks in the cargo area of an oil tanker at sea, other than slop tanks, may be discharged by gravity below the waterline, provided that sufficient time has elapsed in order to allow oil/water separation to have taken place and the ballast water has been examined immediately before the discharge with an oil/water interface detector of the kind referred to in regulation 15(3)(e), in order to ensure that the height of the interface is such that the discharge does not involve any increased harm to the marine environment.

(e) dirty ballast water or oil contaminated water from cargo tank areas of an existing oil tanker may be discharged below the waterline, subsequent to or in lieu of discharge by the method referred to in subparagraph (d), provided that—

(i) a part of the flow of such water is led through permanent piping to a readily accessible location on the upper deck or above where it may be visually observed during the discharge operation; and

(ii) such part flow arrangements comply with the requirements set out in Schedule 3 in Merchant Shipping Notice No. 1643/MARPOL 1.