Hong Kong Regulations

MERCHANT SHIPPING (CONTROL OF POLLUTION BY NOXIOUS LIQUID SUBSTANCES IN BULK) REGULATIONS - REGULATION 4

Category A - tank washing in all areas

(1) A tank from which a Category A substance has been unloaded shall be washed
before the ship leaves the port of unloading.

(2) The resulting tank washings should be discharged into a reception facility
at that port and washing and discharge shall, subject to paragraph (5),
continue until the washings at the point of discharge into the
reception facility are at or below the level of concentration of-

   (a)  0.1% by weight, or 0.01% by weight in the case where the substance in
        question is phosphorus (yellow or white), if the ship is not in a
        Special Area; or

   (b)  0.05% by weight, or 0.005% by weight in the case where the substance
        in question is phosphorus (yellow or white), if the ship is in a
        Special Area. (L.N. 186 of 1995)

(3) After the tank washings at the point of discharge into the reception
facilities reach a level of concentration at or below the prescribed
concentration, discharge from the tank shall be continued until the tank is
empty.

(4) The level of concentration of the Category A substance in the washings at
the point of discharge shall be ascertained by analysis of samples taken at
that point and verified by a Marpol surveyor or, where there is no
Marpol surveyor at that port, by the master.

(5) Where a Marpol surveyor at the port of unloading, or where there is no
Marpol surveyor at that port, the master, is satisfied that it is not
practicable to measure such level of concentration without undue delay to the
ship at that port, the requirements of paragraph (2) shall be sufficiently
complied with if-

   (a)  the tank is pre-washed in accordance with the procedures specified for
        that tank and substance in the Procedures and Arrangements  Manual;
        and

   (b)  the Marpol surveyor at the port of unloading or, where there is no
        Marpol surveyor at that port, the master, records in the Cargo Record 
        Book that-

        (i)    the tank and its pumps and piping systems have been emptied;
               and

        (ii)   the pre-wash has been carried out in accordance with the
               pre-wash procedure approved for that tank and that substance in
               the ship's Procedures and Arrangements Manual; and

        (iii)  the tank washings resulting from such pre-wash have been
               discharged to a reception facility and the tank is empty.
               (Enacted 1987)