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Home/Radon Testing/Fairfax County/Great Falls, VA
Radon testing
A continuous monitor on the lowest level that could be used regularly, read every hour for at least 48 hours. The written result comes the day we collect it.
4.9 rating, over 4,000 reviews NRSB-certified technicians Serving Fairfax County
A radon test in Great Falls is $185, or $175 when it is added to a home inspection. That is the whole price: both visits, the monitor for the full 48 hours, and the written report with every hourly reading in it. The standard Great Falls service is scoped to one residence. A guesthouse, caretaker unit or separately occupied apartment should be listed before booking so each requested dwelling can be priced.
Day 1
Drop-off
A technician places it on the lowest level that could be used regularly, following EPA placement limits and the intended use of the space, inside a two-hour arrival window. With a home inspection, placement happens during the inspection visit.
48 hours
The house stays closed
For a short-term real-estate test, EPA guidance calls for closed-building conditions for at least 12 hours before the test and throughout the measurement. Windows stay closed, exterior doors open only for normal entry and exit, and the monitor logs hourly readings that help document the test conditions during the minimum 48-hour measurement.
Day 3
Pick-up and report
A technician picks the monitor up in another two-hour window and pulls the full record on the spot. The written report reaches you the same day.
NRSB-certified technicians. Our own team, certified by the National Radon Safety Board, not a subcontractor.
EPA testing guidance. Placement, closed-house conditions and the 48-hour minimum follow it, and your average is read against the EPA action level of 4.0 pCi/L.
Continuous monitors. Airthings Corentium Pro instruments, logging every hour for the whole test.
Appointment times are requests until our team confirms them. What the number means, how to prepare the property and the eight questions everyone asks are on the radon testing page; this page is about Great Falls.
Fairfax County is designated EPA radon Zone 1, but this county-scale map does not forecast the result at a Great Falls residence. EPA instructs people not to use zone maps as the deciding factor for testing an individual home. Walk the technician through the lowest level that could be used regularly, including finished rooms and plausible future-use space. A secure position away from direct airflow and routine disturbance is selected only after the specific layout and authorized scope are understood.
A Fairfax County parcel report checked on September 9, 2026, assigns a single-family detached land-use code to one parcel in Great Falls West. The evidence concerns that one parcel only; it is not a statistic for Great Falls West or the wider community and says nothing about indoor radon. Other owners should identify their own residence type. Even at the cited parcel, a database code would not establish the home’s lower-level arrangement, occupancy or appropriate measurement point.
Local background: Fairfax County parcel report for one Great Falls West parcel, checked September 9, 2026, Virginia Department of Health indoor radon map, EPA radon zone map limitations.
01
Provide driveway landmarks, gate operation and a phone number that works at the property. Test the entry arrangement before both visits, particularly if the house will be vacant.
02
List the main house, guesthouse and any occupied accessory unit individually. Confirm which residence the client wants measured and obtain permission from the person controlling that space.
03
Finish storage moves and service work before setup, then prevent pets or visitors from contacting the device. Maintain normal building operation through the stated collection time.
Where we test in Great Falls, and what to tell us
Falcon Ridge, Great Falls Estates
In Falcon Ridge or Great Falls Estates, tell the office whether a gate, long drive or alarm affects entry. The technician needs a workable plan for setup and return collection.
Locust Hill, The Reserve
For Locust Hill or The Reserve, distinguish the main residence from any guest or staff quarters. The order must say which dwelling is authorized rather than treating one parcel as one interior space.
Hidden Springs
Around Hidden Springs, identify a lower room that could receive regular use and keep the route clear. Storage, exercise equipment or household projects should not crowd the monitor.
We do not install radon systems, so we have nothing to gain from your number. If the result is at or above the EPA action level of 4.0 pCi/L, you choose who fixes it. Once the system is in, we can test again and tell you what it reads.
Virginia's residential disclosure statute directs the seller's disclosure statement to say that the owner makes no representation about whether the property is in an EPA Zone 1 or Zone 2 locality. It directs buyers to use due diligence, including reviewing EPA, Virginia Department of Health and NRSB information and ordering a radon inspection before settlement as the contract allows.
Va. Code section 55.1-703. Current as of September 2026. General information, not legal advice.
No. The cited county record assigns a land-use code to one Great Falls West parcel only. It cannot establish the building type, lower-level use or radon condition of nearby properties.
Identify it as a separate dwelling when requesting service and explain its occupancy and access. The main-residence appointment does not automatically include another habitable structure on the parcel.
Send gate credentials, alarm steps, driveway directions and two reliable contacts before placement. Confirm that authorization will still work when the monitor is due for collection.
State the contingency cutoff, any restricted access days and the final useful reporting time. The scheduler can assess whether placement, the 48-hour minimum, retrieval and review fit that window.
Book online or call (703) 450-6398.
Schedule a radon test Request a price
NextDay Inspect
46179 Westlake Dr, Ste 200, Sterling, VA 20165
(703) 450-6398
