RMS Post-Mitigation Testing 3 — Questions and Answers
Question 1: What is the primary purpose of performing a post-mitigation test rather than relying on system diagnostics alone?
- To comply with state licensing renewal requirements
- To verify that actual indoor air radon levels have been reduced to acceptable concentrations (Correct answer)
- To measure fan static pressure after installation
- To document sub-slab aggregate permeability
Correct answer: To verify that actual indoor air radon levels have been reduced to acceptable concentrations
System diagnostics confirm the fan and piping are functioning, but only an air quality test can verify that radon concentrations in breathing air have been reduced.
Question 2: When interpreting post-mitigation short-term test results, what factor can most significantly skew the reading higher than normal long-term averages?
- Continuous HVAC operation during the test
- Elevated wind speeds and low outdoor temperatures (Correct answer)
- Use of a charcoal canister instead of an E-PERM
- Testing during summer months
Correct answer: Elevated wind speeds and low outdoor temperatures
High wind and cold temperatures increase the stack effect in homes, which can draw more radon from the soil, producing higher-than-average short-term readings.
Question 3: A mitigator places a post-mitigation test device in a storage closet in the basement. Why is this placement improper?
- Closets are too small for accurate diffusion
- The device must be placed in a frequently occupied area of the lowest livable level (Correct answer)
- Storage areas have higher humidity that interferes with charcoal canisters
- Closets often have gaps that allow outside air infiltration
Correct answer: The device must be placed in a frequently occupied area of the lowest livable level
Test devices must be placed in frequently occupied spaces because the purpose is to assess actual human exposure, not radon levels in unoccupied storage areas.
Question 4: After a successful post-mitigation test, how long does EPA recommend before conducting a routine follow-up test?
- Every 6 months
- Every 2 years (Correct answer)
- Every 5 years
- No follow-up is required after a successful mitigation test
Correct answer: Every 2 years
EPA recommends retesting every two years after a successful mitigation to ensure the system continues to perform adequately over time.
Question 5: Which condition would invalidate a post-mitigation short-term radon test result?
- The HVAC system cycled on and off normally during the test
- A window was opened for 3 hours during the middle of the test period (Correct answer)
- The test was conducted during a rainstorm
- Occupants were present in the home during the test
Correct answer: A window was opened for 3 hours during the middle of the test period
Opening windows or doors during a short-term test violates closed-house conditions and introduces outdoor air that dilutes radon, making the result invalid.
Question 6: A post-mitigation test returns a result of 1.2 pCi/L. The client asks if they need to do anything further. What is the correct response?
- Recommend immediate system upgrade to achieve 0 pCi/L
- Inform them the level is well below the EPA action level and suggest retesting in 2 years (Correct answer)
- Advise that any level above 1.0 pCi/L requires corrective action
- Tell them no further radon-related actions are ever needed
Correct answer: Inform them the level is well below the EPA action level and suggest retesting in 2 years
A result of 1.2 pCi/L is well below the 4.0 pCi/L action level, and the EPA recommends periodic retesting every two years to ensure continued effectiveness.
Question 7: Which document should be provided to the client after post-mitigation testing is completed?
- Only the fan manufacturer's warranty
- A written report including test results, device information, testing conditions, and mitigation system details (Correct answer)
- An oral summary of findings during a follow-up phone call
- A contractor invoice with radon levels noted in the margin
Correct answer: A written report including test results, device information, testing conditions, and mitigation system details
Best practice and many state regulations require a written post-mitigation report documenting all test parameters, device data, and results for the client's records.
RMS Post-Mitigation Testing 3
What is the primary purpose of performing a post-mitigation test rather than relying on system diagnostics alone?