1,643 spills of 13,309 barrels of oil, or 61% of the total 

 number of spills and 85% of the total volume of oil spilled 

 from offshore facilities in that year (Kash et al . , 1973: 291). 



Waste water disposal is another source of oil pollution in 

 the Gulf of Mexico. Waste water is the water from the oil 

 reservoir which is produced with the oil. It is separated from 

 the oil, treated again to remove entrained oil and then deposited 

 into the Gulf. The treatment facilities, however, are not 100% 

 efficient. Government regulations permit a maximum of only 

 50 parts per million of oil in water before disposal but the 

 waste water still accounted for 3,600 barrels of oil introduced 

 into the Gulf of Mexico in 1971. This is a rate of 9 barrels 

 spilled from waste water sources per million barrels of oil/ 

 condensate produced (Kash et al . , 1973: 291-292). 



Most platform fires are believed to be caused by combus- 

 tible hydrocarbon vapors or liquids making contact with arcing 

 electrical or overhead mechanical devices, however, some fires 

 are caused by accidental ignition of fuel, solvent, or heat 

 exchanger fluids and by lightning or static electricity. 

 From 1956 to 1976, there were 180 recorded platform explosions 

 or fires. However, only 9 of these resulted in spills amount- 

 ing to a total of 87,112 barrels (USDI, 1976d; III-8) . 



It should be noted that a survey following the 1970 

 Chevron oil spill did not establish detrimental environmental 

 effects, nor have other accidents resulted in clear documenta- 

 tion of substantial impact. Short-term effects of oil spills 

 include mortality and tissue damage to fishes and invertebrates, 



48 



