Williamsport, MD Radon Mitigation and Testing

Q: What is the average radon level in Williamsport, MD?

Based on 1 user-submitted tests, the average radon level is 12.00 pCi/L.

Q: What EPA Radon Zone is Williamsport in?

Williamsport is in Washington County, EPA Zone 1.

Q: How much does radon mitigation cost in Williamsport?

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

Avg: 12.00 pCi/L

Washington County

EPA Zone 1

1 user test

Williamsport is located in Washington County, Maryland. With 1 user-submitted readings averaging 12.00 pCi/L, the area exceeds the EPA's 4.0 pCi/L action threshold, and testing is strongly recommended for homeowners in the 21795 zip code.

12.00

pCi/L average

Above EPA Action Level

Based on 1 user-submitted radon test for homes in Williamsport, MD. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Williamsport, MD Radon Mitigation

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

Williamsport, MD Radon Testing

Finding qualified radon testing professionals is the first step toward protecting your home.

Williamsport, Maryland Radon Levels

User-submitted radon test readings from homes in the Williamsport area.

Radon Level	City	Home Age	Foundation	Submitted
12 pCi/L	Williamsport, MD	21-50 Years	—	Jan 2026

Have a radon test result for Williamsport? Submit your reading to help other homeowners.

Williamsport Radon Facts

Key details about the radon risk profile for Williamsport and the 21795 zip code area.

EPA Radon Zone

Zone 1 — High Risk

County

Washington County, MD

Zip Code

21795

Predicted Screening Level

> 4.0 pCi/L (Zone 1)

Avg. User Submitted Level

12.00 pCi/L

User Tests Submitted

Williamsport and the 21795 zip code are located in Washington County, which has an EPA assigned Radon Zone of 1. A radon zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Williamsport, MD

What is the average radon level in Williamsport, MD?

Based on 1 user-submitted test, the average radon level in Williamsport is 12.00 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.

What EPA Radon Zone is Williamsport in?

Williamsport and the 21795 zip code are in Washington County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.

How much does radon mitigation cost in Williamsport?

Radon mitigation in Williamsport 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 Williamsport?

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.

Most Active Radon Markets in Maryland

Cities with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
Frederick	8.29 pCi/L	7
Potomac	9.00 pCi/L	6
Hagerstown	8.67 pCi/L	6
Westminster	14.50 pCi/L	4
Baltimore	7.00 pCi/L	4
Annapolis	4.25 pCi/L	4
Upper Marlboro	15.00 pCi/L	3
Edgewater	12.67 pCi/L	3
Bowie	9.00 pCi/L	3
Clarksburg	8.00 pCi/L	3
Gambrills	6.00 pCi/L	3
Elkton	5.33 pCi/L	3
Silver Spring	4.33 pCi/L	3
Chesapeake Beach	14.00 pCi/L	2
Cumberland	9.00 pCi/L	2
Frostburg	9.00 pCi/L	2
Owings	5.50 pCi/L	2
Huntingtown	4.50 pCi/L	2
Mc Henry	20.00 pCi/L	1
Mount Airy	20.00 pCi/L	1