Radon and uranium in private well water are classic “silent” problems: you can’t see, taste, or smell them, but they can be present at levels that matter for your family’s long-term health. If your home relies on a private well, it’s up to you—not a public utility—to understand the risks, test properly, and choose the right treatment. This guide explains where radon and uranium come from, how often to test, and the best whole-house and point-of-use treatment methods, along with annual maintenance and how to handle spent media and resin safely.

Why Radon and Uranium Show Up in Well Water

Radon and uranium both occur naturally in certain rocks and soils. As uranium in bedrock breaks down over time, it creates a decay chain that includes radium and radon gas. Groundwater flowing through these formations can dissolve uranium and carry radon gas into private wells—especially in regions with crystalline bedrock (granite and certain metamorphic rocks) or uranium-rich sediments.

Uranium is a heavy metal that stays dissolved in water as negatively charged complexes, such as uranium carbonates.
Radon is a radioactive gas that can be present in well water and is also a major indoor air contaminant when it migrates through soil and foundation cracks.
Many private wells in the U.S. are not routinely tested for radionuclides, so homeowners often have no idea these contaminants are present.

Because geology varies so widely, the only way to know if your well has radon or uranium is through a certified laboratory test. Even wells on the same road can have very different results.

How Radon Gets into the Home and Drinking Water

Health Risks and Regulatory Benchmarks

Uranium in Drinking Water

Uranium in drinking water is regulated in public water systems under the Safe Drinking Water Act. The U.S. Environmental Protection Agency (EPA) has set a Maximum Contaminant Level (MCL) for uranium of 30 micrograms per liter (30 µg/L or 30 ppb) in community water supplies. For private wells, this standard is not enforceable—but it’s still an important health-based guideline.

Primary health concern: chemical toxicity to the kidneys (nephrotoxicity).
Secondary concern: radiation dose over long-term exposure.

Radon in Water and Indoor Air

Radon in water contributes to indoor air radon when it is released during showering, dishwashing, laundry, and other water uses. The primary health effect is an increased risk of lung cancer from inhaled radon and its decay products.

EPA does not have an enforceable federal MCL for radon in water, but has proposed levels of 300 pCi/L (if no air mitigation is present) and 4,000 pCi/L (if indoor air is mitigated).
For indoor air, EPA recommends mitigation at or above 4.0 pCi/L, and many professionals encourage action at lower levels for long-term exposure.

EPA - Natural Radionuclides in Private Wells

How Often to Test Well Water for Radon and Uranium

Private wells are not regulated like public water systems, so it is the homeowner’s responsibility to test for radon, uranium, and other contaminants. Different states offer specific guidance, but most recommendations fall into a consistent pattern.

Initial test: Test your well at least once for uranium, radon in water, and a general radionuclide screen (such as gross alpha).
Retesting interval (no treatment installed): Repeat testing every 3–5 years, or sooner if the well is deepened, damaged, flooded, or if you notice changes in water quality.
With treatment installed: Test both raw and treated water for the targeted radionuclides at least once per year to confirm that the system is still working properly.

Always use a certified laboratory familiar with radionuclide analysis, and follow your state’s specific guidance if it is more stringent.

Geologic Radon Potential Map of the United States

TapScore - Specialized Radon Water Test

Best Water Treatment Methods for Radon in Well Water

Radon is a gas, so water treatment focuses on stripping radon out of the water and venting it safely outdoors. This is done with specially designed aeration systems installed as a point-of-entry (whole-house) treatment.

Packed-Tower Aeration (PTA)

Packed-tower systems pass water downward through a tall, packed column while air is blown upward. The large air-to-water contact area strips radon gas from the water with very high efficiency.

Typical radon removal: up to 99–99.9%, depending on design and incoming levels.
Preferred option for wells with moderate to very high radon.
Requires a blower, vent piping to the outdoors, and enough vertical space for the tower.

Spray-Induction Aeration

Spray aeration systems use nozzles to spray radon-bearing water into a tank, where it contacts a large volume of air. A fan continuously sweeps radon-rich air out of the tank and vents it outdoors.

Typical radon removal: 90–99%.
Common residential design; smaller footprint than some packed-tower systems.
Nozzles must be cleaned periodically to prevent clogging from hardness or iron.

Spray Induction Whole House Radon Aeration System for Well Water

Bubble-Diffused and Hybrid Aeration Systems

Bubble-diffused aeration uses fine air bubbles released from diffusers at the bottom of a tank. Hybrid systems may combine spray, diffusion, and recirculation to boost efficiency in a compact footprint.

Typical radon removal: about 80–95% for simple diffused systems; 95%+ for well-designed hybrid systems.
Diffusers require cleaning or replacement when scaling or biofilm develops.

Granular Activated Carbon (GAC) for Radon

Whole-house GAC filters can also remove radon by adsorbing the gas onto the carbon surface. However, over time, the carbon and the vessel accumulate radioactive decay products and effectively become a small, low-level radioactive source.

GAC may be suitable for low to moderate radon levels when properly sized.
Spent carbon may require special handling or disposal in coordination with your state radiation control program.
Because of disposal issues, many radon programs prefer aeration over GAC for whole-house radon treatment.

Best Water Treatment Methods for Uranium in Well Water

Uranium behaves very differently from radon. It is a dissolved metal present as negatively charged complexes, so treatment focuses on technologies that remove or reject these ions from the water.

Anion-Exchange Uranium Removal Systems

Strong-base anion-exchange systems are the primary whole-house treatment for uranium. The resin exchanges harmless chloride ions for uranium complexes in the water. During regeneration, a concentrated salt (sodium chloride) brine flushes the uranium off the resin and sends it to drain.

Capable of reducing uranium below the 30 µg/L guideline when properly sized and maintained.
Often installed as a dedicated uranium removal unit before the household water softener.
Regeneration brine and spent resin can contain elevated uranium and must be handled according to local and state regulations.

Reverse Osmosis (RO) for Uranium

Reverse osmosis forces water through a semi-permeable membrane, rejecting uranium and a wide range of other dissolved ions. Most residential uranium applications use RO as a point-of-use system for drinking and cooking water, though whole-house RO is occasionally used in special cases.

Bluonics POU Reverse Osmosis

Highly effective at reducing uranium to very low levels at a single tap.
Requires prefiltration for sediment and chlorine, and adequate drain capacity for the reject stream.
Membranes typically last 2–5 years with good pretreatment and maintenance.

Adsorptive Media (ATOMUS® MD1, Iron-Oxide, GAC)

Several specialty adsorptive media can bind uranium from water, including activated alumina, iron-oxide-based media, and GAC. These are often used as point-of-use cartridges or small tank systems for low-to-moderate uranium levels or as polishing stages after other treatment.

Media life typically ranges from 6 to 24 months, depending on water chemistry and uranium levels.
Spent media may contain accumulated uranium and should be disposed of according to manufacturer guidance and local regulations.

Enpress One E3 Tank with ATOMUS® MD1 cartridge

Water Treatment Application Methods for Well Water

Designing a treatment system for radon and uranium starts with a full water analysis and a clear understanding of how the water is used in the home. Most residential setups use a combination of point-of-entry (whole-house) and point-of-use (drinking water) technologies.

Point-of-Entry (Whole-House) Treatment

Point-of-entry systems treat all the water entering the home and are used when radon or uranium levels are elevated enough that you want protection for every tap, shower, and appliance.

Whole-house radon aeration systems for stripping radon and safely venting it outdoors.
Whole-house anion-exchange uranium filtration for removing uranium before water is softened or conditioned.
Supporting equipment such as iron/manganese filters, sediment filters, and water softeners to protect the resin and downstream plumbing.

In wells with iron, manganese, or hydrogen sulfide, these contaminants should be removed ahead of the uranium anion resin to prevent fouling and loss of capacity. A typical order of equipment might be: sediment filter → iron/manganese/H₂S treatment → uranium anion filter → water softener → carbon or UV (optional).

Point-of-Use (Drinking Water) Treatment

Point-of-use devices are installed at individual taps (often the kitchen sink) and are ideal when radon or uranium levels are modest or when homeowners want an extra layer of protection for cooking and drinking water.

Under-sink RO systems with dedicated faucets for low-uranium drinking water.
Adsorptive media cartridges designed and certified for uranium reduction.

Point-of-use treatment is especially useful when a whole-house solution is not practical, but it does not address exposure to radon from showers or uranium from other household uses.

Whole-House Radon Removal Under the Basement Slab (Active Soil Depressurization)

While water treatment handles radon and uranium in well water, most radon risk in a home comes from soil gas migrating through the foundation. The gold-standard method for reducing radon that enters from the soil is a sub-slab radon mitigation system, also called active soil depressurization (ASD). This system uses a low-volume fan to continuously draw radon-bearing soil gas from beneath the basement slab and vent it outside, before it can enter the living space.

How a Sub-Slab Radon Mitigation System Works

A suction point is drilled through the concrete slab, and a small pit is created in the soil beneath to allow gas to move freely.
PVC piping is connected to the suction point and routed up through the basement, garage, or exterior wall.
A quiet, low-wattage radon fan runs continuously, creating negative pressure under the slab.
Radon-bearing soil gas is drawn into the piping and discharged safely above the roofline outdoors, where it disperses.

The fan does not need to move a large volume of air; it simply needs to maintain a small pressure difference so that soil gas flows into the piping instead of into the house. Properly installed ASD systems typically reduce indoor radon levels by 50–99% and often bring them below 2.0 pCi/L.

Components and Annual Checks

Suction point and piping: sealed penetrations through the slab with properly glued PVC pipe.
Radon fan: usually mounted in an attic, garage, or on the exterior of the home; designed for continuous operation.
U-tube manometer: a simple visual gauge that shows the fan is creating suction. Uneven liquid levels mean the fan is running; equal levels mean the fan has stopped and needs attention.
Discharge point: vent termination located outdoors, above the roofline, and away from windows or other openings.

Maintenance is minimal. Homeowners should check the U-tube manometer regularly and listen for changes in fan noise. Fans often last 7–12 years. Indoor radon should still be retested every 1–2 years to confirm ongoing performance and after any major changes to the home or foundation.

Because ASD systems involve penetrations in the foundation, fan sizing, and code requirements for vent discharge, installation is best handled by a certified radon mitigation professional. In homes on private wells, it is common to use both radon aeration for the water and sub-slab mitigation for the air to address all exposure pathways.

Annual Maintenance and Handling of Spent Filtration Media and Anion Resin

Any system that removes radionuclides will eventually concentrate them in media, resin, or waste streams. Maintenance and disposal should be part of the original design—not an afterthought.

Radon Aeration Systems

Inspect blowers, fans, and vent lines at least once per year.
Clean spray nozzles or diffusers to control scaling and biofilm.
Disinfect tanks as recommended by the manufacturer (often annually).
Test treated water annually for radon to confirm performance.

Anion-Exchange Uranium Systems

Check salt level in the brine tank monthly and keep it above the water line.
Have a professional inspect the control valve, injectors, and brine system yearly.
Test raw and treated water for uranium at least once per year.
Plan for resin replacement every 8–15 years, depending on usage and water chemistry.
Follow manufacturer and local/state guidance for handling spent resin and regeneration brine, because both may contain elevated uranium.

Reverse Osmosis and Adsorptive Media

Replace sediment and carbon prefilters every 6–12 months.
Sanitize RO storage tanks and lines annually.
Replace RO membranes every 2–5 years, based on performance and TDS readings.
Change adsorptive media cartridges on schedule, typically every 6–24 months.
Dispose of spent cartridges or media according to manufacturer instructions and local regulations.

Bringing It All Together: Testing, Treatment, and Long-Term Protection

For private well owners, radon and uranium are important but manageable risks. Start with a certified lab test for both contaminants, then design treatment around your actual numbers and how you use water in the home. Water-borne radon is best handled with dedicated whole-house aeration, while uranium is reliably removed with anion-exchange systems, reverse osmosis, and specialty adsorptive media. At the same time, an under-slab radon mitigation system can significantly reduce radon entering from soil gas.

The key is not just installing equipment, but committing to regular testing, annual maintenance, and safe handling of spent media and resin. Done correctly, you can protect your family’s water, air, and long-term health while getting the most from your well and your water treatment investment.

Radon and uranium in well water are issues that most homeowners never think about—until they learn their well has them. The good news is that both are highly manageable with the right approach. Certified testing gives you a clear starting point, and the treatment methods outlined in this guide offer reliable, proven solutions that protect your family’s water, indoor air, and long-term health.

Radon aeration, under-slab radon mitigation, anion-exchange uranium systems, reverse osmosis, and specialty adsorptive media each play an important role, depending on your water chemistry and how your household uses water. When these systems are sized correctly, maintained annually, and paired with regular follow-up testing, they provide decades of safe, clean drinking water and significantly reduce indoor radon exposure.

The most important thing is to approach radon and uranium like any other part of responsible well ownership: stay informed, test proactively, maintain your equipment, and make decisions based on accurate data—not assumptions. When you do that, you’re not just treating your water—you’re protecting your home, your health, and your family for years to come.

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Radon and Uranium in Well Water: Risks, Testing, and Treatment Options for Your Home