The purpose of this standard is to provide minimum requirements for the design, construction, inspection, and testing of new welded carbon steel tanks for the storage of water at atmospheric pressure. This edition of the standard includes numerous corrections, updates, and new material to clarify some of the existing requirements, that include the following: Section 1 was revised to show the latest edition of references; Section 3 was revised to match the wind exposure definitions of ASCE 7-05; the requirement that dome roofs constructed of aluminum shall comply with ANSI/AWWA D108 was added; the stress evaluation procedure of ASME BPVC Sec. VIII, Div. 2 was added as an acceptable method for evaluating local shell or pedestal stress for anchor chair designs that are based on a detailed analysis; Section 10 was revised to include an erection tolerance multiplier for elements of ground-supported flat-bottom tanks that are designed in accordance with Sec. 3.4.4 and subject to small compressive stresses; Section 11 was revised to make leak testing of the bottom-to-shell joint mandatory for all ground-supported flat-bottom tanks; Section 13 was revised to not require a site response analysis for short-period structure located on liquefiable soils; the site-specific procedure of FEMA 450 was deleted, and the site-specific procedures of ASCE 7-05 were referenced; the scaling requirement for the alternate procedures was clarified; Section 14 was revised to clarify the DMT-thickness requirement for Category 1 and Category 2 materials when impacts are provided; and, Section 15, covering dome roofs constructed of aluminum, was deleted and replaced with a reference to ANSI/AWWA D108.