April 14, 2008                

Dear Licensed Site Professionals and Other Interested Parties:

The MassDEP Bureau of Waste Site Cleanup has recently developed a Standard Operating Procedure entitled "Standard Operating Procedure for Indoor Air Contamination" ("SOP," August, 2007).  This document was written as guidance to MassDEP BWSC staff conducting investigations and remedial activities at sites with known or potential vapor intrusion issues.  The SOP was created to promote a consistent, informed and practical approach for MassDEP staff to follow that achieves the performance standards required by the Massachusetts Contingency Plan ("MCP," 310 CMR 40.0000). 

This SOP is being made available to you as a technical reference that may be informative when conducting work at sites where vapor intrusion issues are of concern.  Please note that because the SOP was written for MassDEP staff, it contains procedural and administrative information that was developed solely for MassDEP staff use and is not applicable to the private sector.  Also note that SOP references to specific equipment for field investigations reflect equipment that MassDEP currently uses.  Such references do not represent endorsements of particular vendors.

This SOP is not a MassDEP policy, and it is not enforceable by any party.  Parties conducting investigations related to vapor intrusion concerns are subject to specific regulatory requirements in 310 CMR 40.0000 that are not described in this document.  The reader is referred to the regulatory requirements of the MCP and published guidance available on-line at http://Mass.Gov/dep.

The Department intends to develop a comprehensive guidance document for use by the regulated community to address the vapor intrusion pathway in the near future and looks forward to working with all interested stakeholders in that effort.