SANITARY SEWAGE SYSTEM RECOVERY ASSESSMENT

File: 011696_129_15_055.txt
Page: 055
Total Pages: 71






                 possible, control of the odor causing compounds in the raw
                 sewage is the best, perhaps only, choice for consideration.


                 ODOR CONTROL-STRATEGY.

                      The strategy for   control is to substantially reduce or
                 eliminate odor compounds from the raw sewage being by-passed
                 prior to its entering the Gulf of Arabia. The strategy would
                 be implemented by chemical control up-:ttream from each outfall
                 site. The location for chemical application would be either
                 at the by-passing pump station or at manholes in the sewer
                 line between the source and the outfall.        Figure 12 will
                 assist in visualizing the strategy implementation. The choice
                 of chemicals will depend on the .' individual chemical
                 effectiveness, availability, and technical afid operational
                 aspects of application.-
                      The timing for implementing the 'strategy for odor.control
                 would depend on the schedule and rate of progress in restoring
                 full service capability in the pump stations currently by-
                 passing to the bay. - It is recommended that this document will
                 constitute a preliminary planning document determining
                 decision points during the next few months.


                 TECHNICAL AND OPERATIONAL ASPECTS OF IMPLEMENTATION:

                      The options for elimination of odors includes chemical
                 oxidation, precipitation, and masking of chemicals causing the
                 odor problem. The recommended approach is a chemical control
                 process utilizing oxidation and precipitation. The oxidant
                 can be air . (oxygen), chlorine, hydrogen peroxide, or
                 hypochlorites (swimming pool chlorine source);         and the.
 would be iron chloride (FeCI2 or Fecl3).
                 The choice of oxidant would depend on availability, cost and
                 operational requirements. The obvious first choice is using
                 air for oxidation in the pumping station wet wellv - this
                 would require an air compressor and piping/diffuser system
                 appropriate to the size, depths and configuration of the wet
                 well. It Is recommended that iron be'used as precipitant for
                 the sulphides (H2S) . be added at the same site as the air as
                 the air would afford mixing 'of the precipitant (Fe) with the
                 raw sewage.
                      The selection of application sites will depend on
                 distances (time of flow) to the shore. operational convenience
                 and control, and the speed of the reaction. This'aspect of
                 operation should be refined as the necessity of implementing
                 the contingency plan is determined through review of recovery.
                 schedules and plans.


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Box ID = BX000000
Unit = CONST ENG LABS  
Parent Organization = CORPS OF ENGS   
Folder Title = SANITARY SEWAGE SYSTEM RECOVERY ASSESSMENT                                                      
Subject = SANITARY SEWAGE SYSTEM RECOVERY ASSESSMENT
Document Number =        129
Image file name = 00000056.tif