Sulfide Generation Modeling as a Tool for Odor Control Master Planning

The Santa Margarita Water District (SMWD) currently operates 13 sewage lift stations; many of them are in series with one another; some have force mains approaching 6,100 m (20,000 ft) in length. Future development could add up to 6 more lift stations, many in series with the existing. SMWD evaluated the impact of these future lift stations on the existing system from an odor control and a cost standpoint. The Pomeroy equations were used to determine the increase in dissolved sulfide concentrations in the lift station wet wells and force mains. The results were calibrated to existing conditions and the equations were used to forecast future dissolved sulfide levels. These concentrations were then converted to sewer atmosphere concentrations and recommendations were made for odor control. These formed the basis for master planning and budgeting process. New development could be conditioned on the basis of the study.