Oregon School District Conducts Radon Testing

In 2015 Oregon state passed House Bill 2931, requiring all school districts to test for the presence of radon and send test results to the Oregon Health Authority (OHA). Radon testing is to be completed by the beginning of 2021. In light of HB 2931, an Oregon school district recently contracted with G2 Consultants to quantify radon concentrations in their schools and associated facilities to determine if additional testing or mitigation efforts were warranted.

The Need for Action

Radon is colorless and has no odor. It can be found in soil, igneous rock, and is sometimes present in well water. It cannot be detected by sight or smell, and occurs naturally in nature. It moves through soil and penetrates buildings through cracks and openings in foundations. This can occur in buildings or homes of any age and structural type (e.g., with or without basements).

Eventually, radon decays into radioactive particles (decay products) that can be trapped in the lungs when breathed in. As these particles decay further, they release small bursts of radiation. This radiation can damage lung tissue and lead to lung cancer over the course of a lifetime. The U.S. Environmental Protection Agency (EPA) sites Radon as the number one cause for lung cancer among non-smokers.

Protocol and Testing

For our client, we established the test protocols based on the OHA guidelines for Oregon Schools. We determined that the short term activated charcoal adsorption test was best to determine radon concentration levels during the first round of testing. To ensure representative sampling, test devices were placed on interior walls at least three feet from doorways, hallways, windows, exterior walls and heating or air conditioning vents. Test devices were placed at normal breathing zone heights (2-6 feet from the floor).

Once sampling was completed, the devices were collected and sent to an accredited lab to be properly analyzed. The results were delivered to G2 for final review.

Test Results

This first round of testing did identify areas throughout the district that exceeded the EPA action level of 4.0 pCi/L. These areas have been scheduled for retesting at the beginning of the next school year. After follow-up testing is complete, we will once again review the results. When a need to lower radon concentrations is confirmed, we provide clients with various mitigation options.

G2 Recommendations

Follow-up, long term radon sampling is scheduled to commence at the beginning of the next school year, in areas where radon concentrations above the EPA’s Action Level were identified. If the follow-up samples are still above the 4.0 pCi/L, the EPA recommends the radon concentrations be reduced to below 4.0 pCi/L. Radon can be controlled through:

  • HVAC systems. Adjustment to the heating, ventilation and air conditioning systems serving a room may reduce radon levels to below the EPA’s Action Level guideline of 4.0 pCi/L.
  • Soil depressurization. A suction fan is used to produce a low-pressure field in soil under the building slab. This low-pressure field prevents radon entry by ventilating the gas outside before it has a chance to get drawn into the building.
  • Building pressurization. Indoor/soil pressure relationships are controlled to prevent radon entry. More outdoor air is supplied than exhausted so that the building is slightly pressurized compared to both the exterior of the building and the sub-soil area.
  • Sealing entry routes. Seals are installed at major entry routes to minimize radon entry.
  • Zone-specific ventilation. A building’s crawlspaces, tunnels, conduits, vaults, etc. may be used to design a system that reduces its elevated radon.


While no level of radon is safe, there are proactive steps that can be taken to reduce its potential for harm. Measurement and reduction are the safest way to combat the harmful effects of radon gas. If you need help with radon testing or recommendations for corrective action, please feel free to contact us. We are happy to help.