Contractors who build circular tanks can choose from a variety of forms - wood or steel, job-built or manufactured, ganged or handset, custom or off-the-shelf. Some forms are adjustable for a wide range of radius dimensions; others can be used for only a single radius. All the methods, properly applied, can produce structurally satisfactory concrete. Which method to use depends on its cost and ability to meet specification requirements - both of which will be influenced by local labor and site conditions.
Many liquid-retaining circular structures built today are for water treatment plants and wastewater treatment facilities. Other tanks are built to contain harmful or potentially dangerous liquids. Since leakage of these structures can become a public health concern, design and construction requirements may be more conservative than those for other reinforced concrete structures. ACI 350R, "Environmental Engineering Concrete Structures," makes recommendations for mortar-tightness of forms, form coatings and cold weather concerns, form ties, tie holes, and surface finish.