Radon in Water, testing for radon, glass of water, The Radon SpecialistRadon in Water

Radon gas can also enter homes through the water supply. Radon dissolves and builds up in water from underground sources, such as wells. The radon in your water can enter the air in your home when you use water for household activities such as showering, washing clothes and cooking. For every 10,000 picocuries per liter (pCi/L) of radon in your water, it is estimated that 1 pCi/L is added to your radon in the air. If your water comes from a lake, river, or reservoir (surface water), radon is not a concern. The radon is released into the air before it reaches your home. Some states like Connecticut, New Hampshire and Vermont recommend fixing radon in water if the levels are above 5000 pCi/L.

The North Carolina Radon Program recommends a radon-in-water advisory be set at two levels. At the moderate level, concentrations between 4,000 and 10,000 pCi/L in water, treatment is considered optional. At the elevated level, concentrations at or above 10,000 pCi/L in water, treatment should be considered in conjunction with the treatment of indoor air radon released from soil gas. In most cases, mitigation of soil gas radon will have the greatest impact on reducing overall radon exposure and will usually take precedence over treatment of radon in water.

Some radon stays in the water. Radon in the water you drink can also contribute to a very small increase in your risk of stomach cancer. However this risk is almost insignificant compared to your risk of lung cancer from radon.

It is suggested by the EPA that if you have elevated air radon levels and are on a private well, you should have your water radon tested.

Removal of Radon from Water

There are only two practical techniques for removing radon from water in a residential setting. One technique uses activated carbon. The carbon adsorbs the radon from the water. The radon then finishes decaying in the carbon. Activated carbon should only be used if the radon water levels are below 5000 pCi/L. This low level is recommended by the EPA because of the concern over the buildup of radioactivity.

Aeration systems are is used on very high levels of radon. The radon is released from the water by bubbling air through the water. The radon is then vented to the outdoors. There is no buildup of radioactive materials when this technique is used. The removal of well over 99% of the radon from the water can be achieved with these units. These units do require the repressurization of the water after it is treated and care must be taken to properly vent the gas. This venting should be done above the roof line just like an air radon system and there should always be an auxiliary fan outside of the living space to provide for the save removal of the gas. Water aeration is considered by the U.S. EPA to be the best available technology for removing radon from well water. Unlike other methods, such as granular activated carbon tanks, aeration does not pose the threat of waste buildup.

Schedule an appointment to have your water tested for Radon



Professional Testing

If you choose to hire someone to perform a radon test, hire only a qualified individual. A Certified Measurement Professional with either the National Environmental Health Association (NEHA-NRPP) or the National Radon Safety Board (NRSB) ensures that the individual has been properly trained to adhere to the strict testing procedures set forth by the Environmental Protection Agency (EPA).

The Radon Specialist uses Radelec's E-Perm Radon Testing Equipment. These Passive devices are among the highest quality most accurate short or long term devices availible for Professional Radon Technicians.

When choosing radon detectors the lowest price may not be your best choice. The level of service, accuracy of detectors, expertise and advice can vary considerably from different suppliers of radon detectors and measurement services. Testing your home for radon to ensure the air you breathe is safe for you and your family is important to us and we strive to provide the highest quality of service.

Rad Elec E-perms are recognized worldwide as the gold standard for accurate and reliable radon testing results. They are known as true integrators because they are constantly collecting and registering the ions generated by the radon decaying inside the chamber. Rad Elec electret ion chamber technology consistently outperformed all other radon testing methods in the USEPA Radon Measurement Proficiency Program. 

How E-PERMs® Work

The Radon Specialist uses E-PERM Radon Testing ProductsAn E-PERM®, also known as an Electret Ion Chamber (EIC), is a passive integrating ionization monitor consisting of a very stable electret mounted inside a small chamber made of electrically conducting plastic.

The electret, a charged Teflon® disk, serves as both the source for ion collection and as the integrating ion sensor. Negative ions produced inside the chamber are collected on the positively charged electret, causing a reduction of its surface charge. The measurement of the depleted charge during the exposure period is a measure of integrated ionization during the measurement period. The electret charge is read before and after the exposure using a specially built non-contact electret voltage reader referred to as the SPER-1 Electret Voltage Reader. Using this data as input to the appropriate formula, one can determine the radon activity present over the duration of the test.

The basic components of the E-PERM® System consist of the electret reader, chambers, and electrets. There are chambers of different sizes and electrets of different sensitivities to meet a wide range of monitoring situations. Typically, a more sensitive electret, referred to as an ST Electret, is used for short-term measurements, and an LT, or less sensitive electret, is used for longer term measurements. They are known as “true integrators” because they are constantly collecting and “registering” the ions generated by the radon decaying inside the chamber.


Test Wells for Radon, The Radon Specialist Greensboro, NC

Testing procedures that must be adhered to obtain accurate results

Radon Testing Unit, The Radon Specialist Greensboro, NCRadon Test Device Placement

EPA recommends that testing device(s) be placed in the lowest level of the home that could be used regularly, whether it is finished or unfinished. Conduct the test in any space that could be used by the buyer as a bedroom, play area, family room, den, exercise room, or workshop. Based on their client's intended use of the space, the qualified testing professional should identify the appropriate test location and inform their client (buyer). Do not test in a closet, stairway, hallway, crawl space or in an enclosed area of high humidity or high air velocity. An enclosed area may include a kitchen, bathroom, laundry room or furnace room.

Preventing or Detecting Test Interference

There is a potential for test interference in real estate transactions. There are several ways to prevent or detect test interference:

  • Use a test device that frequently records radon or decay product levels to detect unusual swings
  • Employ a motion detector to determine whether the test device has been moved or testing conditions have changed
  • Use a proximity detector to reveal the presence of people in the room which may correlate to possible changes in radon levels during the test
  • Record the barometric pressure to identify weather conditions which may have affected the test
  • Record the temperature record to help assess whether doors and windows have been opened
  • Apply tamper-proof seals to windows to ensure closed house conditions; and Have the seller/occupant sign a non-interference agreement

Home buyers and sellers should consult a qualified radon test provider about the use of these precautions.

There are two general ways to test your home for Radon:

Because radon levels vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level. However, if you need results quickly, a short-term test may be used to decide whether to fix the home.

Short-Term Testing

The quickest way to test is with short-term tests. Short-term tests remain in your home from two days to 90 days, depending on the device. There are two groups of devices which are more commonly used for short-term testing. The passive device group includes alpha track detectors, charcoal canisters, charcoal liquid scintillation detectors, and electret ion chambers. The active device group consists of different types of continuous monitors. Electret ion chambers or otherwise known in the industry as E-perms are recognized worldwide as the gold standard for accurate and reliable radon test results. READ MORE

Radon Testing Kit, The Radon Specialist, Greensboro, NCWhether you test for radon yourself or hire a state-certified tester or a privately certified tester, all radon tests should be taken for a minimum of 48 hours. A longer period of testing is required for some devices.

Long-Term Testing

Long-term tests remain in your home for more than 90 days. Alpha track, and electret ion chamber detectors are commonly used for this type of testing. A long-term test will give you a reading that is more likely to tell you your home's year-round average radon level than a short-term test. If time permits (more than 90 days) long-term tests can be used to confirm initial short-term results. When long-term test results are 4 pCi/L or higher, EPA recommends fixing the home.

Doing a Short-Term Test

If you are testing in a real estate transaction and you need results quickly, any of the following three options for short-term Tests are acceptable in determining whether the home should be fixed. Any real estate test for radon should include steps to prevent or detect device interference with the test device.

When Choosing a Short-Term Testing Option

There are trade-offs among the short-term testing options. Two tests taken at the same time (simultaneous) would improve the precision of this radon test. One test followed by another test (sequential) would most likely give a better representation of the seasonal average. Both active and passive devices may have features which help to prevent test interference. Your state radon office can help you decide which option is best. 


Short-Term Testing Options  What to do Next?


  • Take two short-term tests at the same time in the same location for at least 48 hours.


  • Take an initial short-term test for at least 48 hours. Immediately upon completing the first test, do a second test using an identical device in the same location as the first test.
  • Fix the home if the average of two tests is 4 pCi/L or more.

  • Fix the home if the average of the two tests is 4 pCi/L or more.


  • Test the home with a continuous monitor for at least 48 hours.
  • Fix the home if the average radon level is 4 pCi/L or more. 

Radon Mitigation Systems 

Home Foundation Types

Your home type will affect the kind of radon reduction system that will work best. Homes are generally categorized according to their foundation design. For example: basement, slab, concrete poured at ground level; or crawlspace, a shallow unfinished space under the first floor. Some homes have more than one foundation design feature. For instance, it is common to have a basement under part of the home and to have a slab-on-grade or crawlspace under the rest of the home. In these situations a combination of radon reduction techniques may be needed to reduce radon levels to below 4.0 pCi/L.

The Radon Specialist, Types of home foundations that can be treated for RadonRadon reduction systems can be grouped by home foundation design. Find your type of foundation design above and read about which radon reduction systems may be best for your home.

Basement and Slab Homes

In homes that have a basement or a slab foundation, radon is usually reduced by one of four types of soil suction: sub-slab or block-wall suction depressurization system.

Active Sub-slab suction — also called sub-slab depressurization — is the most common and usually the most reliable radon reduction method. One or more suction pipes are inserted through the floor slab into the crushed rock or soil underneath. They also may be inserted below the concrete slab from outside the home. The number and location of suction pipes that are needed depends on how easily air can move in the crushed rock or soil under the slab and on the strength of the radon source. Often, only a single suction point is needed.

We usually get our information from a visual inspection, from diagnostic testing, and/or from our experience. A radon vent fan connected to the suction pipes draws the radon gas from below the home and releases it into the outdoor air while simultaneously creating a negative pressure or vacuum beneath the slab. Common fan locations include unconditioned home and garage spaces, including attics, and the exterior of the home.

Some homes have drain tiles or perforated pipe to direct water away from the foundation of the home. Suction on these tiles or pipes is often effective in reducing radon levels.

One variation of sub-slab and drain tile suction is sump-hole suction. Often, when a home with a basement has a sump pump to remove unwanted water, the sump can be capped so that it can continue to drain water and serve as the location for a radon suction pipe.

Block-wall suction can be used in basement homes with hollow block foundation walls. This method removes radon and depressurizes the block wall, similar to sub-slab suction. This method is often used in combination with sub-slab suction.

The Radon Specialist, Greensboro, Radon Entry Diagram WorkplaceCrawlspace Houses

An effective method to reduce radon levels in crawlspace homes involves covering the earth floor with a high-density plastic sheet. A vent pipe and fan are used to draw the radon from under the sheet and vent it to the outdoors. This form of soil suction is called sub-membrane suction, and when properly applied is the most effective way to reduce radon levels in crawlspace homes.

Another less-favorable option is active crawlspace depressurization which involves drawing air directly from the crawlspace using a fan. This technique generally does not work as well as sub-membrane suction and requires special attention to combustion appliance back drafting and sealing the crawlspace from other portions of the home, and may also result in increased energy costs due to loss of conditioned air from the home.

In some cases, radon levels can be lowered by ventilating the crawlspace passively, or actively, with the use of a fan. Crawlspace ventilation may lower indoor radon levels both by reducing the home's suction on the soil and by diluting the radon beneath the home. Passive ventilation in a crawlspace is achieved by opening vents, or installing additional vents. Active ventilation uses a fan to blow air through the crawlspace instead of relying on natural air circulation. In colder climates, for either passive or active crawlspace ventilation, water pipes, sewer lines and appliances in the crawlspace may need to be insulated against the cold.

I have worked with The Radon Specialist group for 10 plus years. Abe is great to work with. He will meet with the clients, if needed, and explain how and where the system needs to be installed. He is quick to respond to my request also. I highly recommend his services to all of my clients.

Shelly Fogle

The Radon Specialist is a certified Radon Mitigation Contractor specializing in design and installation of high quality, effective radon reduction systems in North Carolina. We service the Winston Salem, Greensboro, Raleigh, Durham and Charlotte areas. We believe in quality and customer satisfaction, and these are our core values. With over 15 years experience in contract work, we have the knowledge and understanding of what works and what does not. If you have a radon problem call us first. We will help you safely solve the problem.

The Radon Specialist is listed with the National Environmental Health Association (NEHA-NRPP) and The National Radon Safety Board (NRSB). We have also helped teach the Radon Mitigation School hosted by Auburn University for new Radon Mitigation Contractors.

We guarantee to bring your radon results below EPA standards of 4.0 pCi/L. We also standby our work with a 12-month warranty on parts and labor. All of our mitigation exhaust fans have a 5-year warranty through the manufacturer.

We are approved by the National Environmental Health Association (NEHA-NRPP) to perform both short-term and long-term radon testing. All testing and radon mitigation systems are done in accordance with EPA Protocols.


  • Radon Mitigation Contractor
  • Radon Lab Analyst
  • General Contractor
  • National Environmental Health Association (NEHA)-Certified
  • National Radon Safety Board (NRSB)-Certified 


Abe has always been quick to respond, and will match or beat any competitor. He is a pleasure to work with.

Brenda Shoaf

Abe Mendez and his team do high quality work. He is extremely knowledgeable and provides a custom solution to effectively manage your home's radon issue. What's more, he treats your home as if it is his very own, assuring your radon system functions and looks great. For my family's safety, I wouldn't trust anyone else to do the job.

Adam B.

For a lot of my first time home buyers, radon is a scary subject. If you're looking for someone local, who will be able to not just mitigate, but speak with the clients and make them feel educated and comfortable, Abe is your guy.

Blake Ginther

Working with Abe makes our lives so much easier! Our success is very dependent upon good vendors to serve our customers well and Abe is certainly one of them. He is timely, dependable, works well with our clients and offers a fair price. When we ask Abe to get a job done, we consider it done and know it will be done well…every time!

Cathy Dupont Richardson
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  • National Radon Safety Board, Radon Specialist, Greensboro, NC

  • National Radon Proficiency Program, NEHA, Radon Specialist, Greensboro, NC

  • AARST member logo, Radon Specialist, Greensboro, NC