Section 13(f) in The Merchant Shipping (Control of Pollution by Noxious Liquid Substances in Bulk) Rules, 2010
(f)discharge of residues of Category X-(i)Subject to the provisions of clause (a), the following provisions shall apply, namely:-(A)a tank from Which a substance in Category X has been unloaded, shall be prewashed before the ship leaves the port of unloading and the resulting residues shall be discharged to a reception facility until the concentration of the substance in the effluent to such facility, as indicated by analyses of samples of the effluent taken by the surveyor, is at or below 0.1% by weight and when the required concentration level has been achieved, remaining tank washings shall continue to be discharged to the reception facility until the tank is empty:
