49 CFR §193.2155

1. (a)The structural members of an impoundment system must be designed and constructed to prevent impairment of the system's performance reliability and structural integrity as a result of the following:
   1. (1)The imposed loading from—
      1. (i)Full hydrostatic head of impounded LNG;
      2. (ii)Hydrodynamic action, including the effect of any material injected into the system for spill control;
      3. (iii)The impingement of the trajectory of an LNG jet discharged at any predictable angle; and
      4. (iv)Anticipated hydraulic forces from a credible opening in the component or item served, assuming that the discharge pressure equals design pressure.
   2. (2)The erosive action from a spill, including jetting of spilling LNG, and any other anticipated erosive action including surface water runoff, ice formation, dislodgement of ice formation, and snow removal.
   3. (3)The effect of the temperature, any thermal gradient, and any other anticipated degradation resulting from sudden or localized contact with LNG.
   4. (4)Exposure to fire from impounded LNG or from sources other than impounded LNG.
   5. (5)If applicable, the potential impact and loading on the dike due to—
      1. (i)Collapse of the component or item served or adjacent components; and
      2. (ii)If the LNG facility adjoins the right-of-way of any highway or railroad, collision by or explosion of a train, tank car, or tank truck that could reasonably be expected to cause the most severe loading.
2. (b)An LNG storage tank must not be located within a horizontal distance of one mile (1.6 km) from the ends, or 1/4 mile (0.4 km) from the nearest point of a runway, whichever is longer. The height of LNG structures in the vicinity of an airport must also comply with Federal Aviation Administration requirements in 14 CFR Section 1.1.