What does the EPA 4.0 pCi/L radon action level mean in Johnson City?

What 4.0 pCi/L is (and is not)

4.0 pCi/L is the EPA recommended action level for mitigation planning. It is not a magic line where risk appears from nowhere. Risk rises with long-term exposure and higher average concentrations. Think of 4.0 as the point where federal guidance says fix the house, based on a valid measurement.

It is also not a local Johnson City rule invented for Washington County. It is national guidance applied to your home's number. Your neighbor's result does not move your threshold.

The 2.0 to 4.0 "consider fixing" band

Between 2.0 and 4.0 pCi/L, EPA guidance says consider action. Many owners retest, improve sealing and ventilation habits where appropriate, or choose to mitigate based on risk comfort, time in the home, and how the house is used. We explain options without scare tactics. A 3.5 is not "fine forever" and it is not an emergency siren. It is a decision band.

Confirmed results at or above 4.0 are clearer: plan mitigation and verify afterward.

Short-term vs longer averages for decisions

Short-term tests answer "what is happening now under these conditions?" Longer tests (or averages of valid short-term runs) smooth day-to-day swings. Continuous monitors can show spikes that look alarming in the moment. For action decisions, lean on protocol averages, not a single midnight bump.

Closed-house conditions still matter for short-term screens. Follow device instructions so the number you act on is fair.

Result near 4.0 and unsure what to do? Call Johnson City Radon at (423) 455-9162.

Why Washington County Zone 1 potential still means test your house

Zone 1 means high potential across the area, not a guaranteed high reading in every home. Plenty of Johnson City houses test low. Plenty test high. The zone label is why testing is wise. It is not a substitute for your result, and it is not permission to skip measurement because "everyone around here already knows."

Test the lowest lived-in floor unless a professional directs a different placement for how you use the house.

Next steps after a result at or above 4.0

Confirm the test was valid. Then plan mitigation sized to your foundation type (slab, crawl, basement, or mixed). After install, retest. Keep records for your own peace of mind and for a future sale. If you are mid-transaction, talk timing with your agent so contingencies and retests line up.

The EPA recommends fixing a home when radon is 4.0 picocuries per liter (pCi/L) or higher. That action level is a practical threshold, not proof that anything under 4.0 is risk-free. EPA also says consider fixing between 2.0 and 4.0 pCi/L. For Johnson City homeowners, treat 4.0 as the clear plan-mitigation line after a valid test.

How we read continuous monitor spikes without overreacting

A continuous monitor can show short bumps when doors open, weather shifts, or HVAC cycles. Action decisions lean on the average that protocol calls for, not a single peak that scared you at midnight. If your report shows both an average and a max, ask which number the tester used for the recommendation.

Bring the full report when you call. We will walk the 4.0 line, the 2 to 4 band, and whether your Johnson City result is ready for mitigation planning or needs a cleaner confirmatory run first.