Vapor intrusion

Comprehensive Vapor Intrusion Training Scheduled For Sept. 8 and Sept. 22, 2026

Posted on by Coreen Fallat

The Interstate Technology Regulatory Council (ITRC) will offer online training on Understanding Vapor Intrusion – Introductory Concepts & Fundamentals on Sept. 8 and Sept. 22, 2026.  

The Understanding Vapor Intrusion training series introduces the concepts and fundamentals of vapor intrusion and presents information on the ITRC’s Vapor Intrusion Toolkit, published in January 2026. DNR staff participated in the development of both the technical resources and training. The toolkit is designed for state regulators but also helps environmental consultants and other industry professionals learn about vapor intrusion. 

The training presents the topics below over two, two-hour sessions. 

Session 1 Topics – Sept. 8, 2026 (noon to 2 p.m. CST) 

  • Vapor intrusion and basic science 
  • Common vapor intrusion scenarios 
  • Introduction to data and decisions 
  • Stakeholder communication 

Session 2 Topics – Sept. 22, 2026 (noon to 2 p.m. CST) 

  • Recap: How vapor intrusion is different 
  • How to assess vapor intrusion 
  • Managing vapor intrusion risk 
  • Closure and exit strategies 

Interested individuals are encouraged to register at the CLU-IN Training & Events webpage. The recorded training will also be available on-demand at the CLU-IN Training Archived Webinars webpage. 

Site-specific questions regarding vapor intrusion in Wisconsin should be directed to the assigned DNR Project Manager. General vapor intrusion questions can be directed to the “Vapor Intrusion Contacts” listed on the DNR’s RR Program Staff Contacts website. 

Reminder – Register To Attend Conduit Vapor Intrusion: Application Of RR-649 And RR-800 On Sept. 17, 2026

Posted on by Coreen Fallat

Register now to attend an upcoming training designed to share information on the role of conduits as a pathway for vapor intrusion. Presenters will go over updates to the publication Guidance: Investigation of Human-made Preferential Pathways Including Utility Corridors (RR-649) and highlight relevant sections for information available in the publication Vapor Intrusion Guidance (RR-800). This session will also offer an opportunity for you to ask questions specific to preferential pathways. 

The training is offered virtually and registration is required. Anyone involved in the investigation, remediation and mitigation of contaminated sites under Wisconsin Statute (Wis. Stat.) ch. 292 and Wisconsin Administrative (Wis. Admin.) Code chs. NR 700 – 799 is encouraged to attend.  

Conduit Vapor Intrusion: Application of RR-649 and RR-800 
Sept. 17, 2026, 11:30 a.m. to 1 p.m.
Register to attend by Zoom 

The training is hosted as part of the RR Program’s Issues & Trends series which provide updates and information from the RR Program on issues related to environmental contamination and cleanup. This session is the final session from the series of trainings hosted in 2026.  

Recordings Available
Recordings of previous presentations and trainings are available in the RR Program’s training library. 

Public Input Opportunity – Guidance: Investigation Of Human-Made Preferential Pathways Including Utility Corridors (RR-649)

Posted on by Coreen Fallat

The Remediation and Redevelopment (RR) Program is seeking input on the updated publication Guidance: Investigation of Human-made Preferential Pathways Including Utility Corridors (RR-649). The publication explains how human-made preferential pathways can influence contaminant migration of vapor and groundwater, soil or surface water and includes specific information on vapor migration in utility corridors. The guidance describes methods and options to assess and sample the pathways to meet the requirements of Wis. Admin. Code § NR 716.11(5)(a) and incorporates new information from studies and investigations published since 2021. 

The document can be found at the RR Program’s Public Notices & Guidance webpage under Current Notices. Comments may be submitted through Sept. 7, 2026, to DNRRRGuidance@wisconsin.gov.

Rescheduled: Deep Dive Into Vapor Intrusion – Application Of RR-800 Planned For Aug. 20, 2026

Posted on by Coreen Fallat

Register now to attend the rescheduled training designed to dive deeper into the steps to address a site with vapor intrusion or the potential for vapor intrusion. The session focuses on the publication Vapor Intrusion Guidance (RR-800). The presenters will share scenarios that explain how to investigate the vapor intrusion pathway and explore the considerations and actions needed after vapor intrusion is identified.

The training is offered virtually and registration is required. Anyone involved in the investigation, remediation and mitigation of contaminated sites under Wisconsin Statute (Wis. Stat.) ch. 292 and Wisconsin Administrative (Wis. Admin.) Code chs. NR 700 – 799 is encouraged to attend.

Session Details
Deep Dive into Vapor Intrusion: Application of RR-800
Aug. 20, 2026, 11:30 a.m. to 1 p.m.
Register to attend by Zoom
Note: If you had registered to attend July 16, you need to re-register to receive the new link.

The training is hosted as part of the RR Program’s Issues & Trends series which provide updates and information from the RR Program on issues related to environmental contamination and cleanup.

Additional Session Planned
Conduit Vapor Intrusion: Application of RR-649 and RR-800 
Sept. 17, 2026, 11:30 a.m. to 1 p.m.
Register to attend by Zoom

Recordings Available
Recordings of previous presentations and trainings are available in the RR Program’s training library.

Note From The RR Program: Sharing Demographic Information With The DNR

Posted on by Coreen Fallat

Understanding building occupancy is important for protecting public health when there is a known risk of indoor air contamination caused by vapor intrusion. Collecting information about the individuals present at a building is referred to as collecting “demographics.” The demographic information can identify if any sensitive populations spend a meaningful amount of time in the building. Sensitive populations may be at an increased risk of adverse short-term (i.e., acute) health effects and primarily include people who are:

  • Under age 15
  • Currently pregnant or may become pregnant
  • Elderly

Risk of indoor air contamination is identified by an exceedance of the indoor air vapor action level (VAL) and/or sub-slab vapor risk screening level (VRSL) for a specific contaminant. When a VAL or VRSL is exceeded, the DNR recommends that the responsible party or their environmental consultant quickly share if any sensitive populations are present in the building. When sharing information with the DNR, the information should be general in nature, indicating whether a sensitive population is present; it should not include personal information such as names, specific ages, personal addresses and individual occupancy habits (e.g., work hours).

When there is a known exceedance of the indoor air vapor action level (VAL) and/or sub-slab vapor risk screening level (VRSL), DNR collaborates with DHS and local health who provide health-based recommendations that consider building occupancy when advising on the health risk, a timeline for a response and the need for immediate or interim actions (Wis. Admin. Code §§ NR 708.05 and 708.11.)

For more information about the risk of contaminated vapor within a building, visit dnr.wi.gov and search “vapor intrusion.”

 

 

Reminder – Register To Attend Deep Dive Into Vapor Intrusion: Application Of RR-800 On July 16, 2026

Posted on by Coreen Fallat

Register now to attend an upcoming training designed to dive deeper into the steps to address a site with vapor intrusion or the potential for vapor intrusion. The session will focus on the publication Vapor Intrusion Guidance (RR-800). The presenters will share scenarios that explain how to investigate the vapor intrusion pathway and explore the considerations and actions needed after vapor intrusion is identified.    

The training is offered virtually and registration is required. Anyone involved in the investigation, remediation and mitigation of contaminated sites under Wisconsin Statute (Wis. Stat.) ch. 292 and Wisconsin Administrative (Wis. Admin.) Code chs. NR 700 – 799 is encouraged to attend.  

Session Details 

Deep Dive into Vapor Intrusion: Application of RR-800
July 16, 2026, 11:30 a.m. to 1 p.m.
Register to attend by Zoom 

The training is hosted as part of the RR Program’s Issues & Trends series which provide updates and information from the RR Program on issues related to environmental contamination and cleanup. This session is the third in a series of trainings scheduled for this year.  

Additional Session Planned 

Conduit Vapor Intrusion: Application of RR-649 and RR-800 
Sept. 17, 2026, 11:30 a.m. to 1 p.m.
Register to attend by Zoom 

Recordings Available 

Recordings of previous presentations and trainings are available in the RR Program’s training library.

Comprehensive Vapor Intrusion Training April 30 And May 12

Posted on by Coreen Fallat

The Interstate Technology Regulatory Council (ITRC) will offer online training on Understanding Vapor Intrusion – Introductory Concepts & Fundamentals over two sessions on April 30 and May 12, 2026.  

The Understanding Vapor Intrusion training series introduces the concepts and fundamentals of vapor intrusion and presents information on using the ITRC’s Vapor Intrusion Toolkit, published in January 2026. DNR staff participated in the development of both the technical resources and training. The toolkit is designed for state regulators but also helps environmental consultants and other industry professionals learn about vapor intrusion. 

The training covers the topics below presented over two, two-hour sessions. 

Session 1 – April 30, 2026 (noon to 2 p.m. CST)
Topics:

  • Vapor intrusion and basic science 
  • Common vapor intrusion scenarios 
  • Introduction to data and decisions 
  • Stakeholder communication 

Session 2 – May 12, 2026 (noon to 2 p.m. CST)
Topics: 

  • Recap: how vapor intrusion is different 
  • How to assess vapor intrusion 
  • Managing vapor intrusion risk 
  • Closure and exit strategies 

Interested individuals are encouraged to register at the CLU-IN Training & Events webpage. The recorded training will also be available on-demand at the CLU-IN Training Archived Webinars webpage. 

Site-specific questions regarding vapor intrusion in Wisconsin should be directed to the assigned DNR Project Manager. General vapor intrusion questions can be directed to the contacts listed on the DNR’s RR Program Staff Contacts website. 

Now Available: Vapor Quick Lookup Tables (RR-136)

Posted on by Coreen Fallat

The updated Guidance: Vapor Quick Lookup Tables (RR-0136) and companion publication History of Changes to Vapor Quick Lookup Tables (RR-0137) are now posted and available online.  

The Vapor Quick Lookup Tables (RR-0136) summarizes indoor air vapor action levels (VALs) and sub-slab, soil gas and groundwater vapor risk screening levels (VRSLs) for chemicals commonly found in Wisconsin based on the U.S. Environmental Protection Agency (U.S. EPA) Regional Screening Levels (RSLs). Changes include updated instructions when calculating the VALs and VRSLs for consistency with the Vapor Intrusion Guidance (RR-800). Additional changes to the publication and to the companion document improve the readability of information in the tables.   

Additional documents and guidance from the Remediation and Redevelopment Program may be found using the search tools available on the publications and forms webpage.    

Contact a DNR vapor intrusion specialist with any questions. 

Update: U.S. EPA Regional Screening Level and Vapor Intrusion Screening Level Calculators

Posted on by Coreen Fallat

The DNR recently learned that the U.S. Environmental Protection Agency (EPA) Regional Screening Level (RSL) Calculator and the Vapor Intrusion Screening Level (VISL) Calculator webpages are currently offline. The DNR uses these calculators to establish soil residual contaminant levels (RCLs) that may be used by responsible parties to meet cleanup standards in Wis. Admin. Code ch. NR 720 and to establish indoor air Vapor Action Levels (VALs) and Vapor Risk Screening Levels (VSRLs), consistent with relevant definitions set forth in Wis. Admin. Code ch. NR 700. We are hoping this is a short-term situation, as the webpages state that the U.S. EPA is working to get the calculators back online as soon as possible.

In the meantime, please continue to use the soil RCLs available in Guidance: Soil Residual Contaminant Level (RCL) Spreadsheet (RR-0151) and the VALs and sub-slab VRSLs available in Guidance: Wisconsin Vapor Quick Lookup Table (RR-0136).

If there is a need to calculate a site-specific RCL, the Risk Assessment Information System’s (RAIS) PRG Calculator may be used as a tool to develop site-specific RCLs, with DNR review and approval (Wis. Admin. Code §§ NR 720.10(2)(c) and 720.12(2)).

VALs not included in Guidance: Wisconsin Vapor Quick Lookup Table (RR-0136) can be calculated on the U.S. EPA’s Generic RSL Tables for “Resident Air” and “Composite Worker Air” using a Target Hazard Quotient of 1 and a Target Cancer Risk of 1×10-5. VRSLs can be calculated from the VALs by applying the appropriate attenuation factor.

Please contact Erin Endsley with any questions about soil RCLs or Jennifer Borski with any questions about vapor levels.

Now Available: Vapor Intrusion Building Evaluation Form

Posted on by Coreen Fallat

The Wisconsin Department of Natural Resources (DNR) developed a new web-based form to assist environmental professionals when completing vapor investigations and mitigation. The new Vapor Intrusion Building Evaluation (Form 4400-011) helps document building-specific information including:  

  • Ownership and occupancy
  • Construction type and use
  • Presence and number of elevators, stairwells and sumps 
  • Water supply source 
  • Wastewater disposal method 
  • Foundation details 
  • Potential vapor sources  
  • Heating, ventilation and air conditioning 

The Vapor Intrusion Building Evaluation form can be downloaded as a PDF and included as supporting information through the DNR’s RR Submittal Portal. 

New users must create a login to access the web-based form.   

Contact the DNR with questions regarding vapor intrusion. Go to the Remediation & Redevelopment Program staff contacts webpage. Click on “Vapor Intrusion Contacts.”