Radon is a radioactive gas that forms from the natural breakdown of uranium in soil, rock and water. If your Prescott home runs on a private well, that water can carry dissolved radon into the house. It has no color, smell or taste, so you cannot tell by looking at a glass of water.
This page explains how well water radon works, how it is tested, and what treatment looks like. Prescott Radon connects callers with licensed and insured local radon testing and mitigation professionals who can look at your situation.
How radon gets from well water into your home
Groundwater picks up radon as it moves through rock. When that water is used inside the house, some of the dissolved radon can be released into the air you breathe. The water itself is not the only path, which is why air and water are looked at as two separate questions.
Homes on city water are not part of this question. It applies to homes that draw from their own well.
Why Prescott homes with wells get a second look
The Granite Dells, just north of Prescott, are made of granite about 1.4 billion years old. The Arizona Geological Survey reports that this granite has an unusually high uranium content, and uranium is where radon comes from. Homes built on or near it should be checked for radon.
The well story has a notable local example. The highest indoor radon level ever measured anywhere was in a home in the Granite Dells area. According to KNAU Arizona Public Radio, that home's problem was solved with sub-floor ventilation and by sealing gaps in the well casing. A gap in a well casing can be a radon pathway, so it is worth having a professional look at it.
This does not mean every well in Yavapai County has a problem. It means a private well is a good reason to test instead of guess.
Test the water and the air separately
Well water is tested separately from air. A water result tells you about radon dissolved in the water. It does not tell you what the indoor air reads, and an air result does not describe your water.
For the air side, the radon testing page covers how a home test works. Results are given in picocuries per liter (pCi/L). EPA recommends fixing a home at 4 pCi/L or higher and suggests considering a fix between 2 and 4 pCi/L. EPA recommends testing all homes below the third floor.
If you want to sort out both questions in one conversation, call (928) 582-8914. A local professional can explain how each test is done for your home.
Treatment options for radon in water
Two approaches are used when well water needs treatment:
- Aeration, which moves air through the water so the radon gas is released and vented away before the water is used in the home.
- Granular activated carbon, which filters the water so the radon is captured in the carbon.
Which option suits a home depends on the well, the test result and the layout of the house. A local professional can talk through the choices after seeing the setup. Cost depends on the home, and professionals give a quote after looking at it.
Air radon is usually the larger concern
For most homes, radon in the air is the larger concern, even when a home has a well. Radon from the ground can enter through cracks in floors and walls, gaps around pipes and wires, sump pits, crawl spaces and other foundation openings. This is true of new and old homes, with or without a basement.
The Arizona Geological Survey notes that radon from the granite is a concern for people who build weather-tight homes on this rock. Prescott sits at about 5,400 feet, and day-to-night temperature swings average nearly 30 degrees F. Houses that are kept closed up against the cold nights can hold radon in.
If an air test comes back high, the usual fix is an active soil depressurization system. The radon mitigation page describes how those systems work. EPA recommends retesting after a system is installed.
Buying, selling or renovating a home with a well
During a home sale, radon tests are often done in the inspection period. If the property has a private well, ask whether the water was tested too. A result from a previous owner may not reflect current conditions, especially after renovations.
This applies across Prescott, from the older homes near downtown and Miller Valley to newer subdivisions toward the Granite Dells, Prescott Lakes and Willow Creek Road. Help is also available in Prescott Valley, Chino Valley, Dewey-Humboldt and the rest of Yavapai County.
Choosing a professional
Arizona does not run a state radon certification program. EPA recommends hiring a nationally certified radon professional, certified through the National Radon Proficiency Program or the National Radon Safety Board. Call (928) 582-8914 to be connected with licensed and insured local professionals who can look at your well and your home.