CMI CMI Remediation Protocols & Post-Remediation Verification 2 — Questions and Answers
Question 1: What are the two types of samples most commonly collected during post-remediation verification (PRV)?
- Air samples and surface samples from the remediated area and an unaffected reference area (Correct answer)
- Blood samples from occupants and surface swabs from visible mold
- Bulk material samples and HVAC duct tape lift samples only
- Only air samples; surface samples are not used in PRV
Correct answer: Air samples and surface samples from the remediated area and an unaffected reference area
PRV typically involves both air sampling (spore trap cassettes) and surface sampling (swab or tape lift) from remediated areas, compared against reference samples from unaffected areas.
Question 2: Before post-remediation air sampling is conducted, what condition must the work area meet?
- All visible mold must be removed, surfaces cleaned, containment barriers still in place, and air settled for a period (Correct answer)
- Post-remediation sampling must occur while active remediation work continues
- All containment must be removed and HVAC restored to normal operation before sampling
- Post-remediation sampling is only valid if done within 24 hours of remediation completion
Correct answer: All visible mold must be removed, surfaces cleaned, containment barriers still in place, and air settled for a period
PRV air sampling should occur after completion of remediation and cleaning, with containment still in place, and after sufficient time for disturbed particles to settle from the air.
Question 3: If post-remediation verification sampling shows mold levels higher than outdoor reference samples, what is the appropriate action?
- Perform additional remediation and cleaning, then re-test (Correct answer)
- Declare remediation complete since indoor air is always somewhat different from outdoor
- Increase the air changes in the HVAC system to dilute the reading
- Accept the results if no visible mold remains
Correct answer: Perform additional remediation and cleaning, then re-test
Elevated mold levels above outdoor reference after remediation indicate incomplete work; additional remediation and re-testing are required until clearance criteria are met.
Question 4: What is an 'aggressive sampling' technique in post-remediation verification and why is it used?
- Disturbing surfaces with a leaf blower or brush before air sampling to dislodge settled spores and stress-test the remediation (Correct answer)
- Using higher-volume air pumps to collect more spores per sample
- Collecting multiple samples simultaneously from different areas
- Aggressive sampling refers to testing within hours of remediation completion
Correct answer: Disturbing surfaces with a leaf blower or brush before air sampling to dislodge settled spores and stress-test the remediation
Aggressive sampling involves mechanical disturbance of remediated surfaces before air sampling to dislodge any residual spores, providing a more sensitive and reliable assessment of remediation completeness.
Question 5: Which document formalizes the results of post-remediation verification and is provided to the building owner?
- Clearance report or post-remediation evaluation report issued by a qualified third-party inspector (Correct answer)
- A verbal confirmation from the remediation contractor
- The original work order signed by the remediation crew
- A certificate from the local health department
Correct answer: Clearance report or post-remediation evaluation report issued by a qualified third-party inspector
A written clearance or post-remediation evaluation report from a qualified, independent inspector documents sampling results, methods, laboratory analysis, and clearance determination for the building owner.
Question 6: What is the primary reason a third party independent of the remediation contractor should conduct post-remediation verification?
- To avoid a conflict of interest where a contractor might certify their own substandard work as complete (Correct answer)
- Third-party testing is cheaper than contractor self-testing
- Only licensed engineers can conduct post-remediation verification
- It is required by EPA law in all US states
Correct answer: To avoid a conflict of interest where a contractor might certify their own substandard work as complete
Third-party verification eliminates the conflict of interest inherent in a contractor certifying their own work, providing objective assurance to the building owner that remediation was successful.
CMI CMI Remediation Protocols & Post-Remediation Verification 2
What are the two types of samples most commonly collected during post-remediation verification (PRV)?