Characteristics of Pima County Aquifer Water Reaching Your Home
Water in Pima County primarily comes from the N100BSNRGB aquifer, with groundwater drawn through wells typically 300 to 800 feet deep. This aquifer supplies residential water systems before it passes through plumbing and fixtures to reach household taps.
Seasonal and Multi-Year Variation in Radon Measurements
Government sampling conducted in 2013 over a three-month span recorded radon-222 levels ranging from 175 to 1410 picocuries per liter (pCi/L) at six separate wells within this aquifer. The median value was 1100 pCi/L. This data set illustrates some natural variation over a relatively short period but does not capture longer-term trends or seasonal shifts beyond that timeframe.
Influence of Plumbing Materials and Age on Radon Levels
After groundwater leaves the aquifer, radon concentration at your tap can be influenced by the type and age of plumbing materials. Certain pipe materials or water heaters may reduce or allow decay of radon before use, but these effects vary widely and are separate from the source water's radon concentration. Determining radon exposure in household water thus requires individual testing rather than relying solely on aquifer data.
Interpreting Radon Concentrations Against Federal Benchmarks
The recorded radon levels in Pima County aquifer wells fall below established federal action thresholds designed to limit health risks, as noted by the U.S. Environmental Protection Agency and other agencies. However, detection means only the presence of radon at measured levels. It is not a violation of any safety standard nor an indication that water is unsafe to use. The federal benchmarks provide guidance on when treatment might be considered to reduce radon levels for household water use.
Comparing Pima County Radon Data with Nearby Areas
While nearby counties or aquifers may have different radon measurement ranges, it is important not to overinterpret these differences as directly applicable to your water. Variability between areas reflects distinct geological and hydrological factors rather than specific household water conditions. Use local data as context, but verify your own home's radon level through a certified laboratory test.
Sample Size and Representation of Pima County Radon Data
The government data for this aquifer is based on six samples from six separate wells, collected within a limited time frame. Though helpful for regional overview, this small sample size means the range and median should be viewed as indicative rather than definitive for any individual household. Radon levels can vary significantly between wells even within the same aquifer.
Determining Your Household Radon Level and Treatment Needs
To understand your home's specific radon concentration, a certified laboratory analysis of your water is essential. This test measures radon in your water supply directly and provides the basis for deciding on treatment.
If treatment is needed, the Pentair Radon in Water Filter system ships ready to configure and is designed to reduce radon levels effectively. It is a documented solution appropriate for households considering radon mitigation in water.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2013-09-04. 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 N100BSNRGB aquifer (Pima County): 6 results from 6 wells, median 1100.0 pCi/L, range 175.0-1410.0 pCi/L; none above any federal threshold