Section 34(1) in The Merchant Shipping (Prevention of Pollution by Oil from Ships) Rules, 2010
(1)Subject to the provisions of rule 4 and sub-rule (2) hereunder, any discharge into the sea, outside special areas, of oil or oily mixtures from the cargo area of an oil tanker shall be prohibited except when all the following conditions are satisfied, namely:-(a)the tanker is not within a special area;(b)the tanker is more than fifty nautical miles from the nearest land;(c)the tanker is-proceeding en route;(d)the instantaneous rate of discharge of oil content does not exceed 30 litres per nautical mile;(e)the total quantity of oil discharged into the sea does not exceed for tankers delivered on or before 31st December, 1979, as defined in sub-rule (46) of rule lA, 1/15,000 of the total quantity of the particular cargo of which the residue formed a part, and for tankers delivered after 31st December, 1979, as defined in sub-rule (45) of rule IA, 1/30,000 of the total quantity of the particular cargo of which the residue formed a part; and(f)the tanker has in-operation an oil discharge monitoring and control system and a slop tank arrangement as required by rule 31 and 29.
