49 CFR § 193.2181 - Impoundment capacity: LNG storage tanks.

---
identifier: "/us/cfr/t49/s193.2181"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 193.2181 - Impoundment capacity: LNG storage tanks."
title_number: 49
title_name: "Transportation"
section_number: "193.2181"
section_name: "Impoundment capacity: LNG storage tanks."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "D"
subchapter_name: "PIPELINE SAFETY"
part_number: "193"
part_name: "LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5103, 60102, 60103, 60104, 60108, 60109, 60110, 60113, 60118; and 49 CFR 1.53."
regulatory_source: "45 FR 9203, Feb. 11, 1980, unless otherwise noted."
cfr_part: "193"
---


# 193.2181 Impoundment capacity: LNG storage tanks.

Each impounding system serving an LNG storage tank must have a minimum volumetric liquid impoundment capacity of:

(a) 110 percent of the LNG tank's maximum liquid capacity for an impoundment serving a single tank;

(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

(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.

[Amdt. 193-17, 65 FR 10960, Mar. 1, 2000]