190 



1969 Amendments ' 



1. What enforcement difliculties does the Coast Guard foresee under the pro- 

 posed operational discharye amendments? In particular what enforcement culpa- 

 bility does the Coast Guard have beyond 50 miles, and what is necessary to prove 

 a violation of the rate of discharge requirement, or the mixture (ppm) require- 

 ment? 



There is no known means of determining the oil content of a discharge once 

 it has entered the sea, unless the oily mixture is in an enclosed body of water 

 of known or measurable quantity. Sample collection in any case is a practical 

 impossibility on the high seas. The "instantaneous rate of discharge of oil con- 

 tent" is even more impractical to determine than oil content of 100 ppm, since it 

 requires knowledge of both the rate of discharge of oil (not oily mixture) in liters 

 per hour and the speed of the vessel at the same instant. Both oil content stand- 

 ards and rate of discharge requirements are essentially unenforceable unless they 

 are grossly violated and the vessel is observed and photographed as the discharge 

 occurs. In the absence of such documentation of a gross violation, the establish- 

 ment of a case rests on the possibility that the oil record book was improperly 

 maintained. The Coast Guard maintains the enforcement ci)pal)ility to board 

 all vessels of Contracting States to the 1954 Convention while they are in United 

 States ports and inspect their oil record books. 



2. Can tankers achieve the 1/15,000 retiuircnients? 



There are two ways of looking at this question, first, is to look at each tanker 

 on an individual, theoretical basis and the second is to look at the worldwide 

 tanker fleet. 



a. For ships on an individual basis the answer is a qualified yes. 



If the sliip is properly designed and if we assume: (1) A ballast level of 45% 

 of full load displacement including some 14—20% in segregated ballast and 

 including .some 12-17% in the lightship weight; (2) a 0.4% clingage factor; 

 (3) that tankers clean only those tanks which are ballasted; and (4) that 

 sufficient voyage time and weather conditions are present to allow the LOT 

 procedure to operate at maximum effectiveness (voyage needs to be at least 

 3-4 days). 



Then tankers could achieve the 1/15,000 requirement if the LOT procedure used 

 is 8(>-92% effective. Several studies show tliat the average LOT procedure is 

 at present approximately 80% effective. Effectiveness of LOT is very dependent 

 on the personnel using the procedure. The answer to question #3. explains 

 some of the problems of LOT. 



b. For the worldwide tanker fleet we can see from Table XX, which is attached 

 with Question #4., that tlie oil discharged from ballasting and tank cleaning, 

 assuming a 90% LOT effectiveness, is approximately twice that allowed by the 



1/15,000 requirement, since the worldwide tanker fleet, on an average, has a 

 lesser amount of segregated ballast then the newer crude-oil ships examined in 

 part a. 



3. Would a load-on-top procedure bring all tankers into compliance with these 

 requirements, including short-haul tankers? 



Load-on-top is a procedure than cannot be used by all tankers. Approximately 

 80% of the world tanker fleet is presently employing some form of LOT. The 

 remaining 20% of the fleet does not use this procedure for a variety of reasons. 

 Some of the problems encountered in using LOT are : 



a. The LOT system cannot be applied to tankers in the nonpersistent oil 

 product trade since finished products cannot be mixed with one another and 

 cannot tolerate salt content in the same way as most crude oils. 



b. Ballast voyages can be so short as to preclude the time necessary for sat- 

 isfactory operation of the LOT systems. 



c. Depending on sea conditions, tlie necessary separation process may not be 

 completely effective. 



d. The ability to accurately determine the oil-water interface in the holding 

 tank is lacking and subsequently results in drawing off a portion of the lower 

 layer of oil along with the water. 



The non-IX)T tankers will need to have some other methods available to allow 

 them to meet the 1/15,000 requirement. 



J/. Assnminfi all tankers complied irith the 1969 discharge requirements, in 

 it possible that the total amount of oil pollution attributable to intentional 

 ves.9cl discharges will actually increase in the long run given the anticipated 

 increase in oil carrying tanker traffic in the next 20 years? 



