How Does Radon Enter Groundwater in Fresno County?
Radon-222 is a naturally occurring radioactive gas formed from the decay of uranium in soil and rock. In Fresno County, it can dissolve into groundwater as it moves through the area's aquifer system. This means that wells drawing water from these geological layers may pick up radon that was present underground, independent of any contamination from surface sources.
How Many Wells and Samples Determine Fresno County's Radon Data?
The U.S. Geological Survey collected 41 radon measurements from 36 different wells in Fresno County's aquifer between December 2013 and April 2014. These wells ranged in depth from 100 to 400 feet. While this dataset offers a credible snapshot of radon presence within the regional aquifer, the relatively limited number of samples means individual wells may have different radon levels. Therefore, this regional data should not be taken as conclusive for any one household's water.
Does Plumbing Material or Age Affect Radon Levels in Water?
Radon is a gas that dissolves in water at the source and does not generally enter water through plumbing materials. The type or age of pipes and fixtures in a home’s plumbing system does not cause or increase radon in water. Thus, plumbing characteristics are separate from and do not influence the concentration of radon originally present in the groundwater supply.
What Sets Radon Apart from Other Water Concerns Like Iron or Hardness?
Unlike minerals such as iron or hardness-causing calcium, radon is a radioactive gas that can pose a unique health consideration. It does not cause staining or taste issues but may require specific treatment methods aimed at gas removal rather than mineral filtration. This fundamental difference means radon treatment addresses different risks and uses different technologies than those designed for common mineral problems.
Does Radon Concentration Fluctuate Seasonally or Over Multiple Years?
The USGS sampling spanned four months, from late 2013 to early 2014, showing radon levels in Fresno County’s aquifer ranging from 114 to 6,700 pCi/L, with a median of 640 pCi/L. This range indicates variability across wells but does not provide detailed seasonal or long-term trend data. Homeowners should recognize that radon levels might fluctuate over time, influenced by factors such as water table changes or well usage, so periodic testing is advisable.
How Do Household Size and Usage Patterns Influence Radon Treatment Needs?
Larger households or multi-residence properties may need treatment systems that handle higher daily water volumes. Seasonal homes or properties with intermittent use should consider how periods of non-use affect system performance and maintenance requirements. Tailoring treatment solutions to the volume and frequency of water use helps ensure effective radon reduction while balancing ongoing upkeep.
Summary: Fresno County groundwater sampling reveals radon presence across multiple wells but does not establish any household’s specific water quality. Understanding radon's natural origin, differentiating it from other water issues, and considering household water use patterns guide the decision on appropriate treatment class. The Autotrol Radon in Water Filter ships ready to configure and offers a documented technology for addressing radon in residential water.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2014-04-08. 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 aquifer (Fresno County): 41 results from 36 wells, median 640.0 pCi/L, range 114.0-6700.0 pCi/L; none above any federal threshold