On May 1, 2006 the Colorado Department of Public Health and Environment (CDPHE) released a draft policy on an interim evaluation and management approach for PCE. Because of the uncertainty over the toxicity of PCE, CDPHE developed this policy to be used in vapor intrusion evaluations until EPA completes it’s review of the toxicity of PCE. CDPHE has proposed using the California EPA inhalation cancer slope factor of 2 x 10-2 per mg/kg/day2 and applying an adjusted child correction factor. Under Colorado’s draft policy an indoor air concentration greater than 31.0 ug/m3 would trigger the need for action to mitigate human exposure. A concentration between 15.5 and 31.0 ug/m3 would trigger the need for further study. The draft policy is open for comment until June 30, 2006. The policy can be found at:

The Indiana Department of Environmental Management has announced its derivation of a draft slope factor for TCE. The new slope factor was used to calculate the Indiana indoor air chronic default closure levels for TCE of 1.2 ug/m3 for residential land use and 7.9 ug/m3 for industrial land use. The comment period on the draft slope factor expired on March 6, 2006. The slope factor document is found at:

In March 2006 the EPA Office of Research and Development published the results of its vapor intrusion sampling effort near the Raymark Superfund site in Stratford, CT. A sub slab probe installation and sampling method, which was developed as part of this project, is described in detail. Indoor air was sampled in 15 homes and one commercial building utilizing SilcoCan canisters. An attempt was made to evaluate the usefulness of radon as an indicator compound of vapor intrusion. Air permeability testing in sub-slab media was conducted to support sub-slab depressurization efforts. Three methods of evaluating indoor air infiltration into the sub-slab samples were utilized. The report can be found at:

On June 14 representatives from the New Jersey Department of Environmental Protection will present a vapor intrusion seminar at the Cook College campus in New Brunswick, NJ. The investigation and remedial approach for the vapor intrusion pathway included in the state’s guidance will be covered. There is a tuition fee and more information can be found at:

There is a vapor intrusion bill making its way through the California legislature. Bill 2092 was introduced by Assemblywoman Loni Hancock on February 17, 2005 to add a section to the California Health and Safety Code. The bill has passed the house is now in the senate for consideration. The bill requires that an initial list of sites with known or potential vapor intrusion for hazardous substances be compiled by January 1, 2008. The responsible parties would be required to sample to determine the extent of the problem. A uniform strategy would be developed for remediation, engineering and land use controls, and legal mechanisms to assure the long term maintenance of controls. For information on the bill go the attached link and enter “2092”:

The 2006 Midwestern Risk Assessment Symposium will be held in Indianapolis, IN, August 21-24. A soil gas sampling workshop will be held on August 21 and a field work session is included on August 22. Several vapor intrusion presentations are scheduled for August 24 as part of a dry cleaner focus session. Information on this meeting can be found at:

EPA is holding its National RCRA Corrective Action Conference in Providence, RI June 20-21. There will be a vapor intrusion session on June 21 from 10AM - 12noon coordinated by Henry Schuver of EPA. The meeting agenda is found at:

The Air and Waste Management Association will be holding a three day vapor intrusion specialty conference in Los Angeles on September 13-15, 2006. Look for information on this upcoming conference soon at:

The May 2006 edition of LUSTLine contained an article by Robin Davis on vapor attenuation from petroleum hydrocarbon sources. The article summarized data from up to 161 sites. The findings showed significant attenuation of both benzene and TPH vapors. The article concludes that the VI pathway is not likely complete for petroleum vapors if there are at least 5 feet of coarse grained soil or 2 feet of fine grained soil overlying a source. The complete article can be found on page 22 of the LUSTLine edition at: