Technologies and Costs for Removal of Arsenic From Drinking Water

For design flows greater than 1 mgd, the building cost varied based on flow from $100 to $90per square foot.Basis. The data from both the Very Small Systems Document and the Water Model wereexamined to develop housing costs for the activated alumina system. The housing rate listedin the Very Small Systems Document was $40/sq ft (10). This rate includes the following:basic storage building, foundation, electrical wiring, HVAC, and plumbing. The rate is fora pre-fabricated building installed on a concrete slab. The rate is based on data from prefabricatedbuilding manufacturers and the 1993 Means Building Construction Cost Data forstorage buildings multiplied by a conversion factor for small-sized buildings. The housingcosts in the Water Model vary based on size with rates ranging from $87/sq ft for the smallestconceptual design and $50/sq ft for a facility treating approximately 1 mgd (6). The onlydocumentation on the costs in the Water Model states that in lieu of segregating building costsinto several components, the housing category represents all material and labor costsassociated with the building, including heating, ventilating, lighting, and normal convenienceoutlets. However, the fabrication and building type are unknown and, most critically, thesources used to derive the building costs are unknown. The costs in the Water Model weredeveloped in 1983. The ENR Building Cost Index was used to update both sets of costs toSeptember 1998. The housing rate from the Very Small Systems Document was selectedbased on better documentation and the use of more recent data for design flows up to 0.65mgd. For design flows between 0.65 and 1 mgd, a linear regression of housing cost againstprocess area was used to derive the equation listed above. For design flows greater than1mgd, the building cost rate assumptions were the same as those used in the for AlbuquerqueReport (7) and for the case studies in the AwwaRF Report (4).D.2.1Capital Costs - pH Adjustment15. For two options, pH adjustment to the optimal pH 6 is utilized. The capital cost equation forthe pH adjustment module is:Capital cost = 40517 * Design Flow + 31889D-10