The probable effectiveness of the plan for process water waste treatment 

 for any OCS-related facility depends upon such a complex of factors that 

 it is not feasible to discuss them here. Each facility is a special case. 

 Nevertheless, the following description of refinery waste treatment provides 

 s6me idea of the systems used [133J: 



By segregating waste water streams within the refinery, 

 optimum treatment can be obtained by preventing massive dilution 

 of waters that require treatment. All waste water, including 

 rain water, leaving the refinery is divided into five separate 

 systems: 1) high solids, non-oily process waters (water treat- 

 ing plant and boiler blowdown); 2) low solids, non-oil water 

 (roads and general area storm waters); 3) oil waste and process 

 area storm water; 4) salt water waste; and 5) sanitary waste. 



Some of the process water (1 above) is run through an 

 in-plant water treatment plant before release to the disposal 

 system. Treatment consists of: (1) stripping of sour 

 water; (2) co-mingling and treating of spent caustics for 

 organic acid separation and neutralization of the salt water 

 phase, and (3) recycling of phenolic waters to the desalter for 

 phenol recovery. Water issuing from this plant that requires no 

 further treatment is called clear stream water and can be 

 returned directly to the river stream from which it came. 



Oily waste water flows with process area storm water 

 (3 above) through a separator at an average flow rate of 

 1,050 gallons per minute. As a safety measure to prevent any 

 oily material from escaping, each of the three bays in the 

 separator can handle a thousand gallons per minute (gpm) flow. 

 Two bays having a capacity of 2,000 gpm are in operation at all 

 times, with the third available as a spare. The oil is removed 

 by two adjustable-slot oil skimmers and one rotary drum oil 

 skimmer and returned to the refinery for processing. Trash and 

 most of the suspended solids are also removed here. 



The effluent from the separator will be co-mingled with 

 sanitary waste, adjusted for pH as required and pumped to the 

 air flotation unit for secondary treatment. Here the effluent 

 is coagulated to insure recovery of residual oil. Floating and 

 bottom sludge is pumped to the sludge pond for de-watering. 



The air flotation effluent goes to the reuse pond where it 

 may either be pumped as part of the makeup water to an induced 

 draft, cross-flow cooling tower or it will be passed on to the 

 oxidation pond from whence it is discharged. The oxidation pond 

 is equipped with a floating oil skimmer to remove any oil that 

 may have been accidently introduced to the effluent. 



165 



