Technologies and Costs for Removal of Arsenic From Drinking Water

2. The estimated cost of the anion exchange resin was $125/ft 3 for all system sizes.Basis. The November 1999 Technology and Cost Document (2) recommended this cost basedon costs at existing ion exchange facilities and conversations with suppliers. The case studycosts in the AwwaRF Document (4) use a range of $110/ft 3 at 1 mgd to $90/ft 3 at 30 mgd.3. The bed depth assumption ranged from 3 feet to 6 feet depending upon the design flow. Themaximum diameter per column was 12 feet. When the calculated media volume exceeded themaximum, the treatment media was divided into several beds to maintain a realistic beddiameter. Thus, larger designs include multiple anion exchange columns, each treating aportion of the total flow.Basis. The costs for the activated alumina used this approach (6).4. The vessel cost has been sized based on 50% bed expansion during backwash. The vesselvolume was calculated as (1.5)(media volume).Basis. The Water Model used 50% bed expansion to size the vessel (3).5. The vessel cost is based on the following equation:Cost = 63.288 * (Vessel Volume in gallons) ^ 0.679Basis. Quotes were obtained from two manufacturers for glass-lined carbon steel vessels withworking pressure rating between 75 and 150 psi and meeting American Society of MechanicalEngineers (ASME) Code Section VIII requirements. Sizes ranging from 140 gallons to 6764gallons were used to develop the equation. Vessel costs for sixteen different sizes wereregressed against their respective volumes to derive the equation.E-2