1. Rule Out Simple Issues Before Testing
If you notice unusual water characteristics or suspect radon after your existing water treatment equipment has failed, start by checking the most accessible factors. Confirm that your water flow and pressure are normal. Sometimes, problems attributed to radon may relate to equipment malfunction or plumbing issues unrelated to water quality. Since radon is a radioactive gas dissolved in water and odorless, tasteless, and invisible, only specific testing will reveal its presence.
2. Understanding Area Radon Levels: Median and Range
In San Bernardino County’s aquifer N100CACSTL, groundwater sampling by the U.S. Geological Survey recorded radon-222 levels ranging from 151.0 to 16,300.0 picocuries per liter (pCi/L), with a median value of 1,960.0 pCi/L. These figures reflect measurements from 28 results across 25 wells sampled between April and August 2010. This data provides a context for what radon levels might look like in the area but does not specify your household's actual concentration.
3. Reading a Certified Laboratory Radon Test Report
To determine radon concentration in your own water, you need a certified lab test that details radon-222 levels in pCi/L. Such a report will indicate your test result, the reporting limit, and any relevant standards. While the U.S. Environmental Protection Agency recommends an action level for radon in water, no federal threshold was exceeded in the San Bernardino County area samples collected. This means detected radon levels, though measurable, have not surpassed regulated limits in those studies. Your home's individual reading may differ and requires laboratory analysis for an accurate assessment.
4. Sample Size and Its Implications
The radon data for this aquifer is based on 28 measurements from 25 distinct wells. While this is a reasonable dataset to understand regional groundwater radon variability, it remains a limited sample covering wells that varied in depth from 48 to 760 feet. Smaller samples like this provide a snapshot rather than a universal statement for all wells or households in the area. The data serves as a baseline but cannot replace direct testing of your water source.
5. What the Range Means Compared to Federal Standards
Although radon was detected in every sampled well in this aquifer, none of the results exceeded any federal thresholds for radon in water. This does not imply an absence of radon but shows compliance with regulatory limits designed to guide public health. The wide range of measurements from low to higher values indicates natural variability in radon presence in groundwater. Understanding that detection does not equal a violation or a health hazard is critical in interpreting these results.
6. Avoiding Common Misconceptions From Area Sampling Data
It is important not to infer that your specific household water shares the exact radon levels found in these samples. The government data describes a regional aquifer, not your individual source. Testing your own water is the only way to know your specific radon concentration. Also, detection of radon, even at relatively high levels, is not by itself a determination of unsafe water. If you seek to reduce radon in your water after equipment failure, products like the Fleck Radon in Water Filter are designed to address this concern. This system ships ready to configure for your household’s needs, offering a documented solution to radon presence in residential water.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2010-08-19. These figures describe groundwater sampled in this area. They are not a test of any individual private well - only a test of that well can establish its own water.
On record: U.S. Geological Survey sampling of Radon-222 in the N100CACSTL aquifer (San Bernardino County): 28 results from 25 wells, median 1960.0 pCi/L, range 151.0-16300.0 pCi/L; none above any federal threshold