Technologies and Costs for Removal of Arsenic From Drinking Water

Adjustment in staffing or shifting of activities are not included in the incremental labor. Theincremental labor for the activated alumina process without regeneration is one hour per week.In addition, time is also included for media replacement (at 5 percent breakthrough) dependingon the volume of media being replaced. It was assumed that sixteen hours are required toreplace the media for design flows less than 1 mgd and thirty-two hours are required for largerdesign flows. Incremental labor for the pH adjustment processes also is included in the twooptions operated at optimal pH. The incremental labor is an additional two hours per week.5. The labor rate for small systems was $28/hour. The loaded labor rate for large systems was$52/hour.6. The third component in the O&M costs is the energy costs for both the building and theprocess. Housing electrical energy use is based on an annual usage of 19.5 kwh/sq ft/yr,which includes lighting, ventilation, and heating. Process electrical energy was assumed tobe 440 kwh/yr. Costs were based on a rate of $0.08/kwh.The capital and O&M cost curves for activated alumina are shown in figures 3-9 through 3-14.3-40