40 CFR § 147.103 - Existing Class I, II (except enhanced recovery and hydrocarbon storage) and III wells authorized by rule.

---
identifier: "/us/cfr/t40/s147.103"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 147.103 - Existing Class I, II (except enhanced recovery and hydrocarbon storage) and III wells authorized by rule."
title_number: 40
title_name: "Protection of Environment"
section_number: "147.103"
section_name: "Existing Class I, II (except enhanced recovery and hydrocarbon storage) and III wells authorized by rule."
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"
---


# 147.103 Existing Class I, II (except enhanced recovery and hydrocarbon storage) and III wells authorized by rule.

Maximum injection pressure. The owner or operator shall limit injection pressure to the lesser of:

(a) A value which will not exceed the operating requirements of § 144.28(f)(3) (i) or (ii) as applicable; or

(b) A value for well head pressure calculated by using the following formula:

Pm = (0.733-0.433 Sg)d

where:

Pm = injection pressure at the well head in pounds per square inch

Sg = specific gravity of inject fluid (unitless)

d = injection depth in feet.