40 CFR § 141.55 - Maximum contaminant level goals for radionuclides.

---
identifier: "/us/cfr/t40/s141.55"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 141.55 - Maximum contaminant level goals for radionuclides."
title_number: 40
title_name: "Protection of Environment"
section_number: "141.55"
section_name: "Maximum contaminant level goals for radionuclides."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "D"
subchapter_name: "WATER PROGRAMS"
part_number: "141"
part_name: "NATIONAL PRIMARY DRINKING WATER REGULATIONS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11."
regulatory_source: "40 FR 59570, Dec. 24, 1975, unless otherwise noted."
cfr_part: "141"
---


# 141.55 Maximum contaminant level goals for radionuclides.

MCLGs for radionuclides are as indicated in the following table:

| Contaminant | MCLG |
| --- | --- |
| 1. Combined radium-226 and radium-228 | Zero. |
| 2. Gross alpha particle activity (excluding radon and uranium) | Zero. |
| 3. Beta particle and photon radioactivity | Zero. |
| 4. Uranium | Zero. |

[65 FR 76748, Dec. 7, 2000]