# Impoundment capacity: LNG storage tanks.

**Citation:** 49 CFR 193.2181  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

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 cap

## Document text

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]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-193.2181>
- Source ID: `ecfr`
- SHA-256: `534a1c7ca7a403695720ca0a889ba6a34001066c39146901f38d2611c2c97a09`
- Retrieved: 2026-08-20T05:54:35.243Z
- Exported: 2026-08-23T11:18:40.583Z
- Document slug: `49-cfr-193-2181`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "193",
  "section": "193.2181",
  "subpart": "Subpart C—Design",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```