Below is some important information about radon testing in our schools and the steps we're taking to ensure the safety of our learning environments.
What is radon and why does this matter?
Radon is a naturally occurring gas that can be found in buildings everywhere. While it's invisible and odorless, monitoring radon levels is an important part of maintaining healthy indoor air quality. The good news is that when elevated levels are detected, there are proven, effective ways to address them.
Our testing process:
Maine law encourages, but does not require, all school buildings to be tested for radon every five years, following US Environmental Protection Agency guidelines. As a result, we contracted with a third party, Northeast Test Consultants, and conducted our initial testing last Fall. Northeast Test Consultants is an industrial hygiene consulting firm located in Westbrook, Maine, to which we have a long-term relationship with all aspects of testing and abating indoor air quality as it occurs.
Radon is measured in picocuries per liter of air (pCi/L). The EPA Action Level of 4.0 pCi/L indicates the need to investigate and retest to confirm initial results, followed by steps to reduce radon levels if needed. The initial testing results included a full 48 hours of testing, representing at least 50% unoccupied time.
What we found and what happens next:
The good news is that no spaces in any of our schools are at levels indicating immediate remediation or the displacement of students and staff.
This initial radon survey did, though, identify some areas of potential concern at Mabel I. Wilson and Greely High School. No areas of concern were found at Greely Middle School. Some areas in our buildings produced readings that require retesting to confirm the levels. This is a normal part of the process—retesting helps ensure accuracy before any action is needed. Follow up testing will include an hourly Continuous Radon Monitor to evaluate the effectiveness of the HVAC system in reducing radon levels during occupied hours.
Radon testing is best handled during cold weather conditions, and we have scheduled this follow up during the month of November 2026. The areas requiring retesting include spaces with initial results of 4.0 pCi/L or greater:
Mabel I. Wilson School
Rooms 2104, 2105, 2206, 2204, 2119, Gymnasium, Cafeteria/MPR, Kitchen Office 1, Kitchen Office 2, Nurse’s Old Office (Current Admin offices), Office Conference Room, Conference Room 2 (Current Nurse’s Office)
Greely Middle School
No retesting needed at this time.
Greely High School
Rooms 115, 133, 134, 135, 146, Beh Specialist, Wood Tech, Phys Ed Office 2
Our commitment to you:
The safety of our students and staff is our top priority. We are committed to:
- Completing retesting promptly in the identified areas (November 2026)
- If retesting continues to indicate concerns, implementing appropriate mitigation measures where needed, which may include reviewing HVAC systems, sealing foundation gaps, improving ventilation, or installing specialized systems
- Keeping you informed throughout this process with clear, timely updates
For more information:
Radon testing and mitigation are routine building maintenance practices used successfully in schools, homes, and businesses nationwide. Follow-up testing will help us more accurately identify any problem areas that may require further mitigation. For more information about radon, check out A Citizen's Guide to Radon (EPA). To review the district’s 2026 initial radon testing results, click on this link to the district's Facilities page: https://www.msad51.org/apps/pages/facilities. You can also find indoor air quality test results on this page.
Please don't hesitate to contact Don Gray, Director of Business Services ([email protected]), or myself ([email protected]) if you have questions. I will provide updates as our retesting and other necessary steps proceed.
Thank you for your partnership in maintaining safe, healthy learning environments for our students and staff.