Smithfield, NC Radon Levels

Q: What EPA Radon Zone is Smithfield in?

Smithfield is in Johnston County, EPA Zone 3.

Q: Why are radon readings shown from areas near Smithfield?

No homeowner radon tests have been submitted for Smithfield yet, so readings from the closest cities and the Johnston County average are used as the best available indicator of local conditions. The EPA recommends testing every individual home.

Q: How much does radon mitigation cost in Smithfield?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Check local Smithfield radon levels and find certified testing and mitigation professionals to keep your home safe

Smithfield, NC Radon Facts

EPA Radon Zone Zone 3 — Low Risk < 2.0 pCi/L (Zone 3)

County Johnston County, NC

Zip Code 27577

Located in Johnston County within the Raleigh Metro area, Smithfield sits on Coastal Plain sediments and Triassic basin formations that generally produce lower radon potential across eastern North Carolina. The community has experienced significant growth with newer subdivisions complementing historic downtown areas, featuring a mix of slab-on-grade and crawl space construction. Although testing data is limited for zip code 27577, homeowners may still want to establish baseline radon levels through professional testing in this EPA Zone 3 area.

5.00

pCi/L area average

Above EPA Action Level

Johnston County average: 5.00 pCi/L, based on 1 user-submitted test across 1 city in the county. No homeowner readings have been submitted for Smithfield itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Smithfield, NC Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Radon Readings Near Smithfield, NC

No homeowner tests have been submitted for Smithfield yet. The closest cities with user-submitted radon data are shown below — explore them to gauge local conditions. Radon varies by home, so testing is the only way to know your level.

City	Distance	Avg User Level	Readings
Benson	13.0 mi	5.00 pCi/L	1
Wendell	20.3 mi	20.00 pCi/L	1
Zebulon	22.5 mi	9.00 pCi/L	1
Raleigh	28.0 mi	9.00 pCi/L	1
Apex	31.4 mi	3.50 pCi/L	2
Cary	31.8 mi	5.00 pCi/L	4
Lillington	34.5 mi	5.00 pCi/L	2
Wake Forest	34.5 mi	4.50 pCi/L	2

Johnston County Radon Profile

Johnston County is classified as EPA Radon Zone 3, the lowest predicted-risk tier, with modeled indoor screening averages below 2 pCi/L. Homeowner-submitted tests from 1 city in Johnston County average 5.00 pCi/L across 1 test — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in Johnston County.

Radon FAQ for Smithfield, NC

What EPA Radon Zone is Smithfield in?

Smithfield and the 27577 zip code are in Johnston County, which has an EPA assigned Radon Zone of 3. A zone of 3 predicts an average indoor radon screening level less than 2 pCi/L.

Why are radon readings shown from areas near Smithfield?

No homeowner radon tests have been submitted for Smithfield yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Johnston County average—are the best available indicator of local conditions until Smithfield homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.

How much does radon mitigation cost in Smithfield?

Radon mitigation in Smithfield typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in Smithfield?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.