StacksVerified U.S. regulatory reference

49 CFR §193.2181

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Each impounding system serving an LNG storage tank must have a minimum volumetric liquid impoundment capacity of:
  1. (a)110 percent of the LNG tank's maximum liquid capacity for an impoundment serving a single tank;
  2. (b)100 percent of all tanks or 110 percent of the largest tank's maximum liquid capacity, whichever is greater, for the impoundment serving more than one tank; or
  3. (c)If the dike is designed to account for a surge in the event of catastrophic failure, then the impoundment capacity may be reduced to 100 percent in lieu of 110 percent.