40 CFR § 147.3106 - Area of review.

---
identifier: "/us/cfr/t40/s147.3106"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 147.3106 - Area of review."
title_number: 40
title_name: "Protection of Environment"
section_number: "147.3106"
section_name: "Area of review."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "D"
subchapter_name: "WATER PROGRAMS"
part_number: "147"
part_name: "STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 300f  and 42 U.S.C. 6901"
regulatory_source: "49 FR 20197, May 11, 1984, unless otherwise noted."
cfr_part: "147"
---


# 147.3106 Area of review.

(a) When determining the area of review under § 146.6(b) of this chapter, the fixed radius shall be no less than one mile for Class I wells and one-half mile for Class II and III wells. In the case of an application for an area permit, determination of the area of review under § 146.6(b) shall be a fixed width of not less than one mile for the circumscribing area of Class I projects and one-half mile for the circumscribing area of Class II and III projects.

(b) However, in lieu of § 146.6(c) of this chapter, if the area of review is determined by a mathematical model pursuant to paragraph § 146.6(a) of this chapter, the permissible radius is the result of such calculation even if it is less than one mile for Class I wells and one-half for Class II and III wells.