law: Indian Ports Act, 1908
  21. Improperly discharging ballast 
  (1) No ballast or rubbish, and no other thing likely to form a
  
  bank or shoal or to be detrimental to navigation, shall, without lawful excuse,
  
  be cast or thrown into any such port or into or upon any place on shore from
  
  which the same is liable to be washed into any such port, either by ordinary or
  
  high tides, or by storms or. land-floods 28[and no oil or water
  
  mixed with oil shall be discharged in or into any such port, to which any rules
  
  made under clause (ee) of sub-section (1) of section 6 apply, otherwise than in
  
  accordance with such rules].
  (2) Any person who by himself or another so casts or throws any
  
  ballast or rubbish or any such other thing 28[or so discharges any
  
  oil or water mixed with oil], and the master of any vessel from which the same
  
  is so cast, 29[thrown or discharged], shall be punishable with fine
  
  which may extend to five hundred rupees, and shall pay any reasonable expenses
  
  which may be incurred in removing the same.
  (3) If after receiving notice from the conservator of the port
  
  to desist from so casting or throwing any ballast or rubbish or such other
  
  thing 28[or from so discharging any oil or water mixed with oil],
  
  any master continues so to cast, 30[throw or discharge the same], he
  
  shall also be liable to simple imprisonment for a term which may extend to two
  
  months.
  (4) Nothing in this section applies to any case in which the
  
  ballast or rubbish or such other thing is cast or thrown into 28[or
  
  the oil or water mixed with oil is discharged in or into] any such port with
  
  the consent in writing of the conservator, or within any limits within which
  
  such act may be authorized by the 2[Government].