Term Identity
What the term means in an annual report
Combined radium is a specific paired-isotope measurement, not a catch-all radiation result.
Why it may appear
Systems report combined radium monitoring to summarize the two-isotope result for the named sample period.
How it may be printed
Reports may say Combined Radium or, in a reviewed row with matching context, Radium, and usually show pCi/L plus MCL and MCLG fields.
- Other names you may see
- Combined Radium; Radium
- Common report labels
- Combined Radium; Radium
Evidence
Official sources for this explainer
Use official federal, state, utility, or report sources before treating a page as final.
- Supports
- Combined-radium identity; Distinct radionuclide standards
- Retrieved
- 2026-07-11
- Reviewed
- 2026-07-11
Federal regulation
- Supports
- Combined radium-226 and radium-228 calculation; MCL context
- Retrieved
- 2026-07-11
- Reviewed
- 2026-07-11
- Supports
- Annual-report purpose and reporting context; Report-period interpretation and official next steps
- Retrieved
- 2026-07-11
- Reviewed
- 2026-07-11
Regulatory Context
How to read the applicable rule language
Use this Combined radium 226 and 228 context to read a report's printed fields; it does not replace the report or the current official rule.
Framework
The federal combined-radium calculation adds radium-226 and radium-228. This topic does not absorb gross alpha, beta/photon activity, uranium, or other radium concepts.
Limit or program terms
- MCL
- MCLG
- Combined isotope result
Units and source context
Combined radium is commonly reported as activity in pCi/L. Preserve the report's exact label, unit, period, and isotope context.
What this page does not duplicate
A shorter Radium label maps here only through an explicit reviewed row whose source criterion identifies the combined-radium concept.
No standalone numeric limit table is rendered here. Read the source report's printed criterion and the current official source together.
Interpretation Boundaries
What a listed result does not establish
These Combined radium 226 and 228 boundaries apply to every report row connected to this explainer.
Household-level boundary
A system annual-report activity result does not establish current conditions at a particular tap.
What to verify next
Continue Reading
Related explainers and report-reading guides
Read about topics related to Combined radium 226 and 228, or use a guide to understand the report as a whole.
Radionuclides
Gross alpha particle activity
Gross alpha is an activity measurement for alpha-emitting radioactivity. It does not identify one specific substance and is not equivalent to radium, beta/photon activity, or uranium.
Read the Gross alpha particle activity contaminant guideRadionuclides
Beta particle and photon radioactivity
Beta particle and photon radioactivity uses a dose-based federal standard. A 50 pCi/L gross-beta screening level is not the federal MCL.
Read the Beta particle and photon radioactivity contaminant guideRadionuclides
Uranium
Uranium is a regulated radionuclide reported as a mass concentration. It must remain separate from gross alpha activity, combined radium, and beta/photon dose context.
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