40 CFR § 147.3107 - Mechanical integrity.

---
identifier: "/us/cfr/t40/s147.3107"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 147.3107 - Mechanical integrity."
title_number: 40
title_name: "Protection of Environment"
section_number: "147.3107"
section_name: "Mechanical integrity."
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"
---


# 147.3107 Mechanical integrity.

(a) Monitoring of annulus pressure conducted pursuant to § 146.8(b)(1) shall be preceded by an initial pressure test. A positive gauge pressure on the casing/tubing annulus (filled with liquid) shall be maintained continuously. The pressure shall be monitored monthly.

(b) Pressure tests conducted pursuant to § 146.8(b)(2) of this chapter shall be performed with a pressure on the casing/tubing annulus of at least 200 p.s.i. unless otherwise specified by the Director. In addition, pressure tests conducted during well operation shall maintain an injection/annulus pressure differential of at least 100 p.s.i. throughout the tubing length.

(c) Monitoring of enhanced recovery wells conducted pursuant to § 146.8(b)(3), must be preceded by an initial pressure test that was conducted no more than 90 days prior to the commencement of monitoring.