Gross alpha in California well water
In California, 6% of 382 tested private well samples exceeded the EPA limit for gross alpha (15 pCi/L).
Gross alpha is a screening test for radioactive elements in water, mainly radium and uranium from granite bedrock. A high result means one of those is present and the specific test should follow. Alpha emitters raise cancer risk when swallowed over years.
Check your gross alpha number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your California well for gross alpha
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Systems that remove gross alpha
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Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For gross alpha
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for gross alpha in California: certified labs, state programs and prices.
By county, from individual samples
Public monitoring samples against the EPA limit (15 pCi/L); counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| San Diego | 53 | 100% | 9.25 | 170 pCi/L | |
| Tehama | 223 | <1% | 0 | 95 pCi/L | |
| Monterey | 78 | 14% | 0 | 12.2 pCi/L |
- Red Bluff CCD, Tehama County<1% of 172
- East Tehama CCD, Tehama County0% of 48
Sources
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. gross alpha counts and shares are listed on each county and town page with their sources.