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Radionuclides

Gross Alpha in Connecticut Drinking Water

By Alexander Snyder, Founder & Water Quality Data Lead

The U.S. EPA sets the legal limit for Gross Alpha at 15 pCi/L. Health-based guidelines are frequently stricter than this federal legal limit, so a level that is legal is not always health-protective.

“The U.S. EPA has set the Maximum Contaminant Level Goal for Gross Alpha at zero, because there is no level of exposure below which there is no risk of adverse health effects.”— U.S. Environmental Protection Agency, Maximum Contaminant Level Goal (MCLG)

Gross Alpha has been detected in 128 Connecticut ZIP codes. Here is what you need to know about gross alpha in your drinking water and how it may affect your household.

What Is Gross Alpha?

Gross alpha activity is a screening measurement for alpha-emitting radioactive particles in water, including radium-226, radon, and uranium. It indicates the total level of alpha radiation rather than a single contaminant. The EPA maximum contaminant level is 15 picocuries per liter, excluding radon and uranium. Elevated gross alpha levels are associated with increased cancer risk, particularly bone and lung cancer.

Is Gross Alpha in Your Water?

Enter your Connecticut ZIP code to find out if gross alpha is in your local water — and see personalized health risks for your household.

Check Your ZIP Code

Health Effects of Gross Alpha

Increased cancer risk (bone, liver, lung, leukemia), bone damage, kidney damage, developmental effects

Safety Guidelines

Legal Limit (MCL)

15 pCi/L

EPA Maximum Contaminant Level

Gross Alpha's health-based safe level is set below the federal legal limit.

Legal limit versus health-based guideline for Gross Alpha in drinking water
StandardLevelSource
EPA Legal Limit (MCL)15 pCi/LEPA

Where Does Gross Alpha Come From?

Naturally occurring radioactive materials (NORM), uranium mining/processing, nuclear facilities, phosphate fertilizers, granite rock formations

How to Reduce Gross Alpha in Your Water

  1. 1Install a point-of-use reverse osmosis system certified to NSF/ANSI Standard 58 for radium and uranium reduction, as these are the most common contributors to elevated gross alpha readings.
  2. 2Use a cation exchange water softener to reduce radium, which is often the primary source of gross alpha activity in groundwater from sedimentary aquifers.
  3. 3If uranium is the primary contributor, an anion exchange resin system is more targeted, since dissolved uranium typically carries a negative charge in groundwater.
  4. 4Request a full radiological analysis from a certified laboratory to identify which specific radionuclides are contributing to the gross alpha reading.

Who Is Most Vulnerable to Gross Alpha?

The safe level of gross alpha varies significantly depending on who is drinking the water. CheckYourTap calculates adjusted safe levels for each member of your household:

Infants (under 1 year)
Toddlers (1-3 years)
Children (4-11 years)
Pregnant women
Elderly (65+)
Adults
Dogs
Cats

A contaminant level that is safe for an adult may exceed guidelines for an infant by 4-8x or more. Check your ZIP code to see personalized results.

Reading this inside ChatGPT or Claude?

This page can tell you the general science, but not what is actually in your water’s gross alpha level — that depends on your exact address. You can get your specific answer two ways:

  • Inside the chat: ask your assistant to “check my tap water with CheckYourTap”. Our connector returns your ZIP code’s measured contaminant levels — including the derived dog and cat safe levels — and, only if you ask it to, can email you the report or arrange a specialist callback.
  • On the web: open CheckYourTap.com and enter your ZIP code for a free 30-second report.

Concerned about Gross Alpha in your water?

Schedule to get your water tested for gross alpha and more — a Valiant water specialist will review your results and arrange testing for your home.

Frequently Asked Questions

Is Gross Alpha in my tap water?
Gross Alpha has been detected in 128 Connecticut ZIP codes. Whether it's in your specific water depends on your local water system. Enter your CT ZIP code at CheckYourTap.com for a free, instant report.
What level of Gross Alpha is safe?
The safe level depends on who is drinking the water. Health guidelines vary by source, but infants, pregnant women, and pets may need much lower levels. CheckYourTap calculates adjusted safe levels for 11 different household member types.
How do I remove Gross Alpha from my water?
Install a point-of-use reverse osmosis system certified to NSF/ANSI Standard 58 for radium and uranium reduction, as these are the most common contributors to elevated gross alpha readings. Use a cation exchange water softener to reduce radium, which is often the primary source of gross alpha activity in groundwater from sedimentary aquifers. For a personalized consultation, contact Valiant Energy Solutions at (475) 557-5107.

Related Contaminants

Check Water Quality by ZIP Code

View all contaminants in Connecticut water

Sources

The legal limits and health guidelines for Gross Alpha on this page come from the following public authorities:

About This Report

This water quality report is compiled from public records filed with the U.S. Environmental Protection Agency, state health departments, and the U.S. Geological Survey. Contaminant levels are evaluated against EPA federal standards and health-based guidelines from leading environmental and public health organizations. CheckYourTap is a service of Valiant Energy Solutions, a Connecticut water quality and energy services company established in 1930.

EPA SDWISUSGS NWISEWG Tap Water DatabaseCA OEHHA Public Health GoalsWHO Drinking Water Guidelines

This report is general information, not medical advice or a substitute for certified laboratory testing. Talk to your pediatrician or physician about specific health concerns.

Reviewed by the CheckYourTap editorial team. Last updated July 2026