The purpose of this standard is to provide guidance to facilitate the design, manufacture, and procurement of welded steel tanks for the storage of water. This standard does not cover all details of design and construction because of the large variety of sizes and shapes of tanks. Where details for any specific design are not given, it is intended that the constructor, subject to the approval of the purchaser, shall provide details that are designed and constructed to be adequate and as safe as those that would otherwise be provided under this standard. This standard does not cover concrete steel composite tank construction. Section 1 covers general topics such as scope, definitions, guarantee, drawings to be furnished, and references. Section 2 discusses material specifications. Section 3 details general design. Section 4 addresses the sizing and design of elevated tanks. Accessories for elevated tanks are discussed in Section 5. Section 6 covers sizing of ground supported standpipes and reservoirs. Accessories for ground supported standpipes and reservoirs are detailed in Section 7. Sections 8 through 15 include welding, shop fabrication, erection, inspection and testing, foundation design, seismic design of water storage tanks, alternative design basis for standpipes and reservoirs, and structurally supported aluminum dome roofs, respectively. The major revisions in this edition of ANSI/AWWA D100-96 include the following: Section 2 includes new data on the types and thicknesses of materials and their uses in tank construction. Section 3 has been extensively revised in the area of design load definitions, and the reference tables, figures and equations used in the design of welded steel tanks. Minimum plate thicknesses, roofs, anchor bolts, and flush-type cleanouts have been defined. The buckling requirements of conical and double-curved shells have been clarified. Section 4 clarifies the design of tension members carrying wind and seismic loads and steel risers. Updates of criteria for accessories including safety grills, overflows, and screening have been added to Sec. 5. Section 7 includes updates similar to those found in Sec. 5. Section 8, concerning the quality control of welders, welding operators, and welding inspectors, has been expanded to improve quality control during construction. Critical joint details, materials, and sizes of welds are also clarified. Section 10 has been revised to better define temperature limits for welding and limits of weld reinforcement.' Section 11 includes extensive changes concerning the inspection of welded joints. Tank shell, tubular support, columns, tension member bracing, and large diameter riser joints are discussed, and radiograph requirements have been revised. The penetrometer techniques and details have also been revised to conform to ASME criteria. Section 12 has minor changes, and Sec. 12.6 concerning foundations for flat bottom tanks has been revised. Section 13 covering seismic design has extensive revisions updating the methods to calculate forces and stresses. A new seismic map of the United States is included along with new and revised equations for calculating such things as hydrodynamic seismic hoop tensile stresses, and sloshing wave height to determine minimum freeboard. Appendix C of the previous edition has been incorporated into the standard as Sec. 14. Reference standards have been moved to Sec. 1. Electrode criteria and requirements for permanent and temporary attachment criteria have been revised. The type of inspection and number of weld joint inspections have also been updated for better quality control. A new Section 15, entitled Structurally Supported Aluminum Dome Roofs, has been added. It provides the purchaser with the flexibility to choose an alternative roof system. The entire standard was reviewed carefully, and minor changes were made in many of the section to improve understanding and readability. Tabulated values and equations throughout this standard have been revised to include English and SI units of measurement. In the event of a discrepancy between the values, the English values shall govern.