
Radon Testing in Portland, Maine
Radon Is Invisible. Your Decision Shouldn't Be.
Maine-Registered, NRPP-Certified Radon Measurement for Buyers, Agents & Property Owners in Portland
Portland is Maine's largest city, and much of its housing stock was built before 1978 — old foundations, granite-rich soil, and basement living that make radon a real question here. About one in three Maine homes tests at or above the EPA's 4.0 pCi/L action level. You cannot see radon, smell it, or judge the level during a walk-through — you have to measure it.
In a recent HarborLight test in Portland's Deering Center neighborhood, one unit in a duplex measured 1.8 pCi/L while the garden-level unit measured 9.6 pCi/L — more than double the EPA's 4.0 action level. The lower unit was fully occupied. The tenant had no idea.
MAINE NUMBERS THAT MATTER
4.0 pCi/L or higher: the State of Maine advises action.
2.0–4.0 pCi/L: consider reducing the level.
A residence being tested for sale must be tested by a registered radon service provider.
VERIFIED PROFESSIONAL CREDENTIALS
Michael J. Marquis — Maine Small Residential Principal, PSM50530
HarborLight Property Inspections, LLC — Maine Small Residential Company, SMC507
NRPP Certified Radon Measurement Professional 116213-RMP
Radon in water is a separate test. HarborLight's service on this page is radon-in-air measurement only.
One professional. One continuous monitor. One clear report before closing.
THE $275 PORTLAND RADON DUE-DILIGENCE PACKAGE
$275 STANDARD RESIDENTIAL RADON TEST
• Professional placement and closed-building-condition guidance
• Continuous radon monitor deployment
• Approximately 48-hour minimum measurement period
• Monitor retrieval and professional data review
• Clear, transaction-ready final report
• Plain-English explanation of the result
• Direct access to Michael if questions come up
NO MAIL-IN KIT. NO GUESSWORK. CLEAR CONTEXT.
THE CLARITY PROMISE
You will not be handed a number and left to figure it out. If your report is not clear, Michael will personally walk you through the result and the practical next questions.
HOW IT WORKS
1. Book as soon as the property and inspection deadline are known.
2. HarborLight deploys the monitor and measures for approximately 48 hours.
3. We retrieve it, review the data, deliver the report, and explain the result.
Inspection periods move fast. Radon measurement needs time. Schedule early so the testing window does not become the decision bottleneck.
WHAT YOUR RESULT MEANS
Below 2.0 pCi/L: lower measured level; keep your report and follow recommended retesting.
2.0–4.0 pCi/L: Maine advises considering reduction.
4.0 pCi/L or higher: Maine advises action. A qualified mitigation professional can explain reduction options.
COMMON QUESTIONS
How long does it take? Approximately 48 hours under proper closed-building conditions.
Where is it placed? In the appropriate lowest livable area.
Can the seller test a home for a sale? Maine requires testing for a residence for sale to be performed by a registered radon service provider.
How often should a home be retested? Maine recommends every 3–5 years, after significant renovation or soil disturbance, and every 2 years for mitigated homes.
Does this include well-water testing? No. Radon in water is a separate test; HarborLight's advertised service here is radon-in-air measurement.
WHAT PORTLAND HOMEOWNERS SAY
Elijah (5 stars): "Great experience with HarborLight Property Inspections. Very quick and responsive, fit us in on a pretty tight timeline, and got the inspecion done with no problems. Will definitely use again."
Marten (5 stars): "Mike was fantastic to work with start to finish. He was responsive and thorough throughout the process. And very helpful and patient explaining the report to us afterwards! Highly recommend!"
Alex (5 stars): "Mike has been an incredible resource as worked with him through lead inspections and remediation planning for a new property. We got to know him has a very thoughtful, reliable and exceptionally knowledgeable specialist."
SERVING PORTLAND
HarborLight provides radon testing in Portland and nearby Cumberland County communities, including South Portland, Scarborough, Westbrook, Gorham, Falmouth, and Cape Elizabeth.
Serving the following Portland, ME zip codes: 04101, 04102, 04103, 04104, 04109, 04112, 04122, 04123, 04124.
Official guidance source: Maine CDC Radon Program.
Know Before You Close.™ Schedule your $275 radon test today: (207) 245-4688.
mike@harborlightinspections.com | 443 Western Avenue #1135, South Portland, ME 04106


HarborLight also offers lead inspection and asbestos inspection. Learn more about radon testing in Maine.

