# Classes of impounding systems.

**Citation:** 49 CFR 193.2153  
**Type / status:** regulation / historical  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 1999-10-01  
**Published:** Not stated

(a) For the purpose of this part, impounding systems are classified as follows:

Class 1. A system which surrounds the component served with the inner surface of the dike constructed against or within 24 inches (610 millimeters) of the component served. Class 2. A system which surrounds the componen

## Document text

(a) For the purpose of this part, impounding systems are classified as follows:

Class 1. A system which surrounds the component served with the inner surface of the dike constructed against or within 24 inches (610 millimeters) of the component served. Class 2. A system which surrounds the component or area served with the dike located a distance away from the component or at the periphery of the area. Class 3. A system which conducts a spill by dikes and floors to a remote impounding space which does not surround the component or area served.

(b) In the case of an impounding system consisting of a combination of classes, requirements of this part regarding a single class apply according to the percentage of impoundment provided by each class.

[45 FR 9203, Feb. 11, 1980, as amended by Amdt. 193-16, 63 FR 37505, July 13, 1998]

## Provenance

- Official: Yes
- Source: <https://www.govinfo.gov/app/details/CFR-1999-title49-vol3/CFR-1999-title49-vol3-sec193-2153>
- Source ID: `govinfo-cfr`
- SHA-256: `d70c1ffca6dea7233a6e805989a9c085be9d541f5a735e4758157abbb5f51d14`
- Retrieved: 2026-08-12T01:41:23.231Z
- Exported: 2026-08-22T23:15:04.928Z
- Document slug: `49-cfr-193-2153`

### Source metadata

```json
{
  "part": "193",
  "section": "193.2153",
  "subpart": "Subpart C—Design",
  "annualEdition": 1999,
  "revisedAsOf": "1999-10-01",
  "govInfoPackage": "CFR-1999-title49-vol3",
  "legalStatus": "official-annual-cfr-edition",
  "effectiveDateNote": null,
  "historicalAnchor": true,
  "historicalAnchorNote": "The section appears in an official annual CFR edition but is absent from the connected current eCFR corpus.",
  "jurisdiction": "US"
}
```