Radon in Harris County Water: Understanding Area Levels and Your Next Steps

Radon in residential water is a concern that requires careful interpretation of regional data and personalized testing. In Harris County, Texas, the U.S. Geological Survey has sampled groundwater within the local aquifer (121EVGL), providing insight into the radon levels typically found in the area. However, these measurements reflect the area as a whole, not your individual well or water source.

If you understand that secondary standards are about aesthetic, not health, concerns

Radon is a naturally occurring radioactive gas that can dissolve into groundwater. State and federal guidelines include secondary standards related to taste, staining, and corrosion potentials, which are distinct from health-based limits. The federal thresholds for radon in water exist to guide risk management, but the detected values in Harris County samples have not exceeded any enforceable health-based limits. Thus, while high radon can be undesirable, exceeding secondary aesthetic thresholds does not imply water is unsafe by federal health standards.

If you want to interpret detected radon values, medians, and ranges in Harris County’s aquifer data

The groundwater sampling in Harris County’s aquifer recorded radon-222 in 23 tests across 12 wells between mid-2013 and mid-2015. Radon was detected in every test, with a median concentration of 950.0 pCi/L and a range from 640.0 to 2510.0 pCi/L. These values show regional radon presence but do not predict your home's radon level. Detection means instruments found radon; it is not a violation or automatic cause for alarm. The median provides a middle point of the measured values, while the range indicates the variability across sampled wells.

If you compare public water system records with private well testing results

Public water systems in the region maintain records with regular monitoring for radon and other constituents, adhering to federal requirements. These records may differ from private well testing, which more accurately reflects your household’s specific water conditions. Public records represent broad system-wide data and are useful for understanding general trends but cannot substitute for a current and localized test of your own water. For households with private wells or older equipment, such as when existing radon-reduction devices have ceased functioning, a current laboratory test of your water sample is critical to determine the need for treatment.

If you have a large household, a second home, or a seasonal property

Homes with larger water use or seasonal occupancy may experience different radon concerns. A large household uses more water, potentially drawing from different well sections and possibly affecting radon concentrations. Seasonal or second homes might face fluctuations in groundwater chemistry or require different maintenance schedules for water treatment systems. Testing water quality at the tap is especially important after periods of inactivity or when water equipment has stopped functioning, to ensure radon levels remain managed within desired parameters.

If you consider ongoing maintenance for radon control equipment

The documented solution for radon in household water, the Autotrol Radon in Water Filter, ships ready to configure for your setup. It requires routine maintenance to continue reducing radon effectively. Maintenance schedules depend on your water usage, radon levels, and system design but typically involve monitoring filter media and replacing components at intervals recommended by product guidelines. Proper maintenance ensures that the system continues to reduce radon presence in your water, addressing concerns that arise when previous equipment has failed.

Regional sampling shows radon exists in Harris County groundwater without exceeding federal health limits, but only your own water test can determine your home's radon concentration. If your current radon treatment equipment is no longer functioning, consider water testing and a radon reduction system like the Autotrol Radon in Water Filter to restore control over radon levels in your household water supply.

Where this information comes from

Source: USGS groundwater sampling. Sampled 2015-07-20. 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 121EVGL aquifer (Harris County): 23 results from 12 wells, median 950.0 pCi/L, range 640.0-2510.0 pCi/L; none above any federal threshold