Gross Alpha Radionuclides


What are Gross Alpha Radionuclides?
Gross Alpha Radionuclides are radiological contaminants specifically identified by measuring the concentration of radionuclides that emit alpha particles and this test procedure provides for targeted testing for radioactivity from Radium 224 and 226 using a NJDEP modified 48 hour Rapid Gross Alpha test method. Although radiological contaminants have numerous origins such as atomic energy, medical diagnosis and treatment, and mining of radioactive materials, the NJDEP has identified that certain locations in southern New Jersey have elevated levels of naturally occurring radioactivity in drinking water being drawn from the Kirkwood - Cohansey aquifer. Water of high radioactivity is unusual; nevertheless, it is known to exist in certain areas, from either natural or man-made sources.

How is Gross Alpha tested?
A properly collected and preserved sample must be obtained. The “holding time” (i.e., time which Gross Alpha must be analyzed after sample collection) is 36-48 Hours. The NJDEP certified test method is modified to require expedited initial counting to “capture” the radioactivity of the short half-life for Radium 224.

What is the current Standard?
If the calculated values from the initial gross alpha count is less than 5 pCi/L (picocurie per liter), that value shall be reported. However, if the gross alpha count exceeds 5 pCi/L, then the sample shall be recounted between 20 to 28 hours after the initial count, and this calculated value shall be reported as the final gross alpha result and shall not exceed the Maximum Contaminant Level (MCL) of 15 pCi/L.

What are the potential Health Effects with ingesting Radioactivity in water?
The potential health effects are cancer causing.

Should I continue to use my water if the Gross Alpha is not within the MCL?
You should alert the local health agency and follow their advice.

What steps can I take to reduce Gross Alpha levels in my water?
Short Term:
purchase bottled water.
Long Term: 1.)
Connect to public water 2.) Well replacement 3.) Water Treatment: Point of Entry Treatment System (POET) or Point of Use (POU) Treatment System with water softener, ion exchange, or reverse osmosis. Also, the water can be set aside for > 4 days to reduce the radioactivity from the Radium 224. 4.) Contact you local Health Agency and a Water Treatment Professional.

If you install a water treatment system, be sure to conduct another test after the water has been treated to verify that the system is working effectively.

Where can I go for more information?
Your best help may be your local Health Agency. Also, go to the Helpful Links section of this website.


This information is meant to serve as a basic overview of the material discussed. Always obtain professional advice prior to implementing a plan of action.