Vapor intrusion best management practices

Vapor Intrusion Best Management Practices

The MPCA has developed procedures for vapor intrusion mitigation and public communication work that will be used by MPCA and our contractors for doing these aspects of vapor intrusion work. The procedures and documents were developed working closely with the Minnesota Department of Health, environmental consultants under contract to MPCA and expert practitioners in radon mitigation.

Vapor intrusion guiding principles — Version 4.0

The vapor intrusion guiding principles are the basis for the more detailed direction and guidance outlined in the vapor intrusion BMP’s.

  • Underground chemical vapors can migrate from the source of contamination through the soil and  building foundations into indoor air creating a health concern.
  • The primary goal of vapor intrusion work is to identify and address potential human health risks.
  • Effective public communication is an essential aspect of vapor intrusion work. This includes public awareness of health risks from vapor intrusion, vapor intrusion areas of concern, areas where mitigation has been installed and areas where more testing is needed.
  • Building mitigation decisions are based on current and future possibilities of a health risk from vapor intrusion.
  • Multiple factors contribute to variations in soil vapor contaminant levels.
  • Seasonal sampling from multiple sampling points are needed to determine there is no vapor intrusion risk.
  • The effectiveness of a mitigation system needs to be verified with confirmation testing.
  • Expedited action is needed when the data indicates the potential for a short-term health risk.
  • A plan is needed to assure continued operation of mitigation systems until data shows continued operation is no longer needed.
  • Future property owners need to be notified of the presence and need for continued operation of mitigation systems or unresolved vapor intrusion risks. 
  • When there is a source creating vapor contamination, the best practice is to remediate the source if feasible.
  • The obligation for addressing the possibility of vapor intrusion into a building and the source of the contamination are different for Superfund responsible parties compared to non-responsible voluntary parties and property owners.
  • A clear and predictable process is important for timely facilitation of property transactions.

Investigation and building mitigation decision best management practices

Map templates

Building mitigation best management practices

PDF icon Diagnostic testing, installation and confirmation sampling for active vapor mitigation systems in single-family residential buildings

Public communication best management practices