The composite elevated tank is well-established as extremely cost competitive, most notably in large capacities. This is due to its well balanced design, efficient use of construction materials, and productive construction practices.
The cost of maintenance is a very significant consideration. Repainting costs continue to escalate along with related environmental regulations, while infrastructure maintenance budgets continue to shrink. The composite elevated tank has the least amount of steel area, and therefore the least potential maintenance of any tank style available. Standard design features allow easy access to all surfaces during inspection and maintenance.
*Blue denotes coated surface
A clear illustration of the maintenance cost difference among elevated tank configurations is shown above in the highlighted comparison of recoating requirements--all areas shown in blue are painted surfaces. For instance, a sample composite elevated tank has interior and exterior tank coated surfaces totalling 53,600 square feet, and no requirements on the support pedestal, for a first recoat cost of $321,600, based on a $6.00 per square foot estimate.
In contrast, a fluted column of identical storage capacity requires coverage for 132, 840 square feet overall, with the tank interior/exterior and support wall exterior based on the same $6.00/square foot estimate, and the support wall interior at $2.00/square foot—for a total cost of $580,480, and a difference of $258,880—a more than 80 percent premium!
The significance of the composite maintenance advantage is best understood by comparing the future coating costs of different tank styles. The bid evaluation performed by the City of Portage, MI, provided in resources, is an example of this analysis. It demonstrates the magnitude and impact of future maintenance on total ownership cost, and the large cost advantage of the composite tank in comparison to all-steel tanks.
Also provided is a comparative life cycle cost analysis program that may be used to determine the net present value (NPV) of maintenance costs over a predetermined evaluation period. The results represent the investment required today (given certain assumptions of average interest and inflation rate, coatings cost, etc.) to cover the maintenance costs of the structure over the life cycle period.
The sample life cycle cost analyses excerpted above are available in complete form for all types of scenarios, along with an evaluation tool on the resources page. These and other tools provided will demonstrate the significant savings available with the composite elevated tank.