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Jerry Lile- DGA L&M OU Action Items Page " <br /> From: Karen DiBiasio <br /> To: Jerry Lile <br /> Date: 6/30/2005 2:17:31 PM <br /> Subject: DGA L&M OU Action Items <br /> Jerry, <br /> have investigated the two action items from our conference call yesterday for Delta Gateway Apartments, <br /> L & M OU to discuss my June 27, 2005 memorandum containing comments from my review of the June 7, <br /> 2005 "Soil Vapor Sampling Work Plan and Response to DTSC HHRA Comments Dated March 3, 2005, <br /> Delta View Apartments, Stockton Parcel 2A, Stockton, California" prepared by Earth Tech in San Jose, <br /> California and received by HERD on June 8, 2005. <br /> 1. HERD requested soil gas samples collected not only from 5 ft, but also at or just above the capillary <br /> fringe for locations now designated as SV-19, SV-23, and SV-24 (formerly designated as SV-2, SV-6, and <br /> SV-7, respectively). <br /> HERD continues to recommend collection of samples not only from 5 ft, but also at or just above the <br /> capillary fringe from the above locations based on the following. Data from a site in Lodi where the source <br /> was leaks from sewer lines, thus a relatively shallow source similar to the L& M OU, the capillary fringe <br /> zone soil gas better predicted the concentrations measured in indoor air than did the shallower(5 ft bgs) <br /> soil gas data. <br /> Currently, DTSC is recommending collection of data from at least these two depths,followed by <br /> conducting preliminary indoor air modeling evaluations to determine which depth data produces the most <br /> conservative prediction of risk, and finally modeling using the soil gas data from the depth that is most <br /> protective of human health for indoor air exposures. HERD is only requesting 3 samples collected from <br /> the capillary fringe zone, not at every soil gas sample location. <br /> 2. HERD requested inclusion of analyses for PAI-Is other than naphthalene using method TO-13 SIM. <br /> Ray Kaminski of EarthTech stated he spoke with a technical advisor from Air Toxics, Ltd and was <br /> informed method TO-13 is for entraining particulates from stack sampling, not collection and analysis of <br /> soil gas. <br /> HERD spoke with Heidi Hayes, Technical Director at Air Toxics Ltd. Method TO-13A, as opposed to <br /> TO-13, is for ambient air. A 300m3 sample is needed. They have done TO-13 modified using a low flow <br /> for sampling and analysis for PAHs. Another alternative she suggested was passive sampling for an <br /> extended duration, perhaps 1-2 weeks to achieve equilibration; then proceed with TO-13A SIM on active <br /> soil gas samples only if PAI-is detected during passive soil gas investigation. <br /> As always, please call me if you have any questions. <br /> Karen W. DiBiasio, Ph.D. <br /> Staff Toxicologist <br /> Human and Ecological Risk Division <br /> Department of Toxic Substances Control <br /> 8810 Cal Center Dr., 2nd Floor <br /> Sacramento, CA 95826-3268 <br /> (916)255-6633 FAX (916)255-6694 <br /> "The energy challenge facing California is real. Every Californian needs to take immediate action to <br />