Radium (226 + 228) in well water
Radium is a naturally occurring radioactive metal in bedrock. It accumulates in bone and raises the risk of bone cancer. It occurs in the same granite areas as uranium and radon.
- EPA limit
- 5 pCi/L (EPA MCL combined radium-226 and radium-228 (40 CFR 141.66))
By individual samples
Counties with at least 30 individual samples in public monitoring data, against the EPA limit.
| County | Samples | Detected | Above EPA limit | Median |
|---|---|---|---|---|
| Grafton County, New Hampshire | 36 | 69% | 0% | 0 pCi/L |
How to test
Use a state-certified lab and a proper sampling bottle; hardware-store strips cannot measure radium (226 + 228) at the levels that matter. Collect from the kitchen tap before any treatment, and again after treatment if you install it.
How to treat
- Water softener (cation exchange)
- Point-of-use reverse osmosis