Please note that this blog is no longer active.

The work to update MassDEP’s Indoor Air Guidance is complete.  MassDEP’s current information is available online at www.Mass.Gov/dep.

These pages are considered “archived” and are no longer updated or monitored.


April 30, 2015 – Vapor Intrusion Guidance Development Meeting

There was a meeting on the draft Vapor Intrusion Guidance on April 30, 2015, from 9:30 am to 11:00 at MassDEP, One Winter Street, Boston, 2nd floor conference rooms A and B.  Draft guidance document and public comments.

The recording of the VI workgroup meeting can be seen at

New USEPA Guidance on TCE

The new (August 27, 2014) document is titled: “Compilation of Information Relating to Early/Interim Actions at Superfund Sites and the TCE IRIS Assessment.”  USEPA describes the document as follows:  “The compilation was prepared in response to requests from U.S. EPA Regional Offices.   It provides information regarding existing EPA guidance on early or interim actions at Superfund sites.   It also provides current information about the toxicity of TCE.  The information referenced in this document may be used to support Superfund decision making at sites with actual or potential inhalation exposures to TCE.

download:  TCE compilation final.pdf (1 MB, PDF file)

Updated TCE Documents

MassDEP has recently made minor revisions to two TCE-related documents (last updated in March, 2014):

  1. TCE Toxicity Information:  Implications for Chronic and Shorter-Term Exposure – Fact Sheet (August 15, 2014)
  2. EPA Trichloroethylene Toxicity Values and ORS Recommendations Regarding Remediation Targets & Timeframes to Address Potential Developmental Risks (August 15, 2014)

New EPA Region IX TCE Guidance

Now available:

EPA Region 9 Response Action Levels and Recommendations to Address Near-Term Inhalation Exposures to TCE in Air from Subsurface Vapor Intrusion

download:  Region IX July 2014.pdf (6.3 MB PDF document)

EPA Comment Period Extended to 6/24

Draft Final Vapor Intrusion Guidance Documents Available for Public Input

EPA is affording the public with an opportunity to provide input on its draft final vapor intrusion guidance documents (see links below). The public may provide input by June 24, 2013 at (EPA-HQ-RCRA-2002-0033).



Revised TCE Status Update

MassDEP has recently revised the TCE Status Update (originally published in January, 2013):

TCE Status Update
TCE Status Update REVISED 4/18/2013 (PDF):   Revised TCE Fact Sheet – 04-18-2013
TCE Status Update REVISED 4/18/2013 (MS Word): Revised TCE Fact Sheet – 04-18-2013
This update provides a summary of the available toxicity information for TCE, the status of the MassDEP review of this information, and an appropriate approach to assessing disposal sites during this review period.



email from the U.S. EPA:

EPA is affording the public with an opportunity to provide input on its draft final vapor intrusion guidance documents. This afternoon [April 16, 2013], the Office of Solid Waste and Emergency Response released for public input two draft vapor intrusion guidance documents: a general guidance for all compounds; and one focused on petroleum hydrocarbons released from underground storage tanks. When final, these guidance documents will help ensure vapor intrusion exposure assessment and mitigation actions to protect human health are undertaken in a technically, scientifically and nationally consistent manner.

The documents can be accessed at:

Public input must be submitted by May 24, 2013, at:; docket number: EPA-HQ-RCRA-2002-0033-007.

Thanks for your interest in EPA’s vapor intrusion guidance.

Rich Kapuscinski

MCP Regulatory Reform Proposal

MassDEP is proposing significant amendments to the Massachusetts Contingency Plan (MCP), 310 CMR 40.0000, as part of the agency’s regulatory reform efforts. The MCP sets forth the procedures and standards for notification, assessment, and remediation of disposal sites resulting from the release of oil and/or hazardous materials to the environment.  These regulations govern the response to sudden oil and hazardous material spills, as well as the assessment and cleanup of Brownfields, properties contaminated by past use as industrial or commercial facilities, prior to their redevelopment and productive reuse. Consistent with regulatory reform goals, the proposed MCP amendments enhance regulatory efficiency in a manner that benefits both parties conducting response actions and MassDEP, while maintaining a high standard of environmental protection.

The proposal include several issues specific to vapor intrusion, including the closure of sites with an active sub-slab system and  consideration of future buildings (and possible vapor intrusion) on currently vacant land.

The MassDEP website ( and then scroll down to the MCP revisions) offers the proposed revisions as both a redline/strikeout document and a “clean” (just the new text) version. The spreadsheets documenting changes to the MCP numerical standards are also available to download, as is a 4-page summery of the proposals.

An extended (until May 17, 2013) Public Comment Period will allow reviewers time to develop comments on this substantial package. MassDEP also expects to hold discussion sessions over the next few months to address specific issues in the proposal.

Updates on TCE & Vapor Intrusion

MassDEP is following other state and federal agencies as they develop approaches to addressing exposure to trichloroethylene, particularly through the vapor intrusion pathway.  Please feel free to send along any additional links you are aware of through the Comments link below.