This publication provides technical guidance and the equation set to determine the maximum impoundment volume required for North American LNG facilities governed by CGA G-19.1, NFPA 59A, or CSA Z276. This publication applies to bulk cryogenic storage systems with LNG. The credible releases and potential spills come from piping. Accordingly, this publication is based on piping releases, up to and including 6 in (150 mm) NPS. The simplified approach presented in Section 6 is specific to pressure vessels. For pipeline facilities, see 49 CFR Part 193. This publication is intended for ASME vessels of 15 psi (103 kPa) maximum allowable working pressure or greater.