As most environmental professionals already know, for the past year ASTM International has been working to develop a standard to assess a property's potential exposure to vapor intrusion. Word is this standard will be published sometime in 2008. Now Congress may be chiming in on the issue.

Senator Clinton (and Dole, Boxer, Lautenberg and Kerry) recently introduced a bill titled the "Toxic Chemical Exposure Reduction Act of 2007" which seeks to amend the Safe Drinking Water Act. As it relates to vapor intrusion, the bill seems to do a few things, namely:

• require EPA to publish a health advisory for TCE that fully protects from vapor intrusion,
• require an integrated risk information system reference concentration of TCE vapor, and
• apply this established reference concentration to any potential vapor intrusion related investigations or actions carried out pursuant to CERCLA, the Safe Drinking Water Act or the Solid Waste Disposal Act.

Now, despite the general vagueness of the above, this does seem to be yet another indicator that the vapor intrusion train has left the station. The best proof of this can be found by simply conducting a Google search (news and blogs) for vapor intrusion and look at the results. There are literally new stories coming out weekly about residential and commercial properties being impacted by vapors.

For our part, we're headed to D.C. in three weeks to meet with the staffs of the above-mentioned Senators to learn more about where they'd like to take this bill and we'll report back on our findings.