---
kind: "section"
citation: "40 C.F.R. § 149.2"
title: "40"
number: "149.2"
heading: "Definitions."
url: "https://uscodex.org/cfr/40/149.2"
---

# §149.2. Definitions.

- (a) Aquifer means a geological formation, group of formations, or part of a formation that is capable of yielding a significant amount of water to a well or spring.
- (b) Recharge means a process, natural or artificial, by which water is added to the saturated zone of an aquifer.
- (c) Recharge Area means an area in which water reaches the zone of saturation (ground water) by surface infiltration; in addition, a major recharge area is an area where a major part of the recharge to an aquifer occurs.
- (d) **Sole or Principal Source Aquifer—**
  - (SSA) means an aquifer which is designated as an SSA under [section 1424(e)](/cfr/40/1424.md?p=e) of the SDWA.

## Notes

### Amendments

[54 FR 6843, Feb. 14, 1989]

### Source

Source: 52 FR 23986, June 26, 1987, unless otherwise noted.

### Authority

Authority: Sec. 1424(e), Safe Drinking Water Act (42 U.S.C. 300h-3(e); sec. 1427 of the Safe Drinking Water Act, (42 U.S.C. 300h-6).

### Amendments

[54 FR 6843, Feb. 14, 1989]