Gross Alpha Activity
EPA MCLG
0 pCi/L
EPA's health goal is zero — no known safe level of exposure. This is a goal, not an enforceable limit.
Health Effects
Increased risk of cancer
Source: EPA — National Primary Drinking Water Regulations (retrieved 2026-09-20)
Common Sources
- Erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation
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The EPA MCLG for Gross Alpha Activity is 0 pCi/L. Upload your water test (PDF or a photo) and we'll email a plain-English reading of where your result lands — and every other number — free. Educational only, no medical claims.
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Upload my testHow to Remove Gross Alpha Activity
How do I get rid of Gross Alpha Activity in drinking water?
For Gross Alpha Activity, the verified treatment is reverse osmosis. Reverse osmosis is a primary treatment. Gross alpha is a screening measure for alpha-emitting radionuclides, including radium-226 and excluding radon and uranium. Where a utility also reports radium separately, the radium answer applies too.
Source: EPA 40 CFR 141.66(g) BAT — gross alpha particle activity (MCL 15 pCi/L)
What filter certification covers Gross Alpha Activity?
Reverse osmosis is certified under NSF/ANSI 58. Check that the certification listing names Gross Alpha Activity or its group: a certification to a standard is not a certification for every contaminant in it.
Source: EPA 40 CFR 141.66(g) BAT — gross alpha particle activity (MCL 15 pCi/L)
Does a basic water filter pitcher remove Gross Alpha Activity?
No. For Gross Alpha Activity, the verified treatment is reverse osmosis — and a basic pitcher is an activated-carbon device, which is not on that list. No pitcher in our index carries a certification for Gross Alpha Activity, so the jug in the fridge is not the answer here.
Source: EPA 40 CFR 141.66(g) BAT — gross alpha particle activity (MCL 15 pCi/L)
Does boiling water remove Gross Alpha Activity?
No — boiling makes it worse. What Gross Alpha Activity measures is non-volatile and dissolved: the water leaves as steam and the radionuclides stay behind, so boiling concentrates them in what remains instead of removing them. For Gross Alpha Activity, the verified treatment is reverse osmosis; no thermal method appears in the corpus at all.
Source: EPA 40 CFR 141.66 BAT for radionuclides (reverse osmosis, ion exchange, anion exchange — no thermal method), plus the physical basis that these are non-volatile dissolved solids
We name no filter for Gross Alpha Activity. The certifiers' listings carry no reviewed claim under this name, so no product can be shown to have been tested against it — and a claim we cannot check is a claim we will not publish. Use the certification above and read the listing for Gross Alpha Activity itself.
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Is Gross Alpha Activity in your water?
Gross Alpha Activity has been recorded above its health guideline in 804 cities, serving 10.0M people. Each system below was judged against a goal of 0 pCi/L.
Most affected systems, by population served
- Newburgh Heights, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Bratenahl, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Cuyahoga Heights, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Linndale, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Cleveland, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Fairview Park, OH1,308,955 people served0.62 pCi/Lgoal 0 pCi/L
- Omaha, NE560,930 people served3.91 pCi/Lgoal 0 pCi/L
- Lakewood, NJ335,449 people served3.15 pCi/Lgoal 0 pCi/L
- Bradley Beach, NJ335,449 people served3.15 pCi/Lgoal 0 pCi/L
- Asbury Park, NJ335,449 people served3.15 pCi/Lgoal 0 pCi/L
and 794 more cities with a recorded result above the guideline
These are the largest systems that reported a result above the guideline — not the highest results. A city missing from this list has not been shown to be clean: it may have no Gross Alpha Activity result on file at all. We publish a level only where a system reported one.
Check your city or ZIP code for Gross Alpha Activity
Part of a group: radiological contaminants
This contaminant is rarely measured on its own. Radiological contaminants in drinking water covers the whole group — what they are, which limits are enforceable, and where they come from.
Others in this group
About the EPA MCLG
The EPA MCLG is the level of a contaminant in drinking water below which there is no known or expected risk to health. It is a non-enforceable public health goal, and is often stricter than the legal limit (MCL) water systems must meet.
Contaminant Type
Gross Alpha Activity is classified as a Radionuclides contaminant.
Related Radionuclides Contaminants
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