SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Former Fayette Manufacturing Page 3 of 3 7675 West Eleventh Street January 16, 2013 Tracy, California • Provide the location where the one indoor air sample is proposed to be collected and include the height of the Summa canister from the floor of the structure. • Notify the occupants of the building in advance of the pending collection of the indoor sample; and two weeks prior to the indoor sampling event, provide written instructions to the office occupants explaining the testing procedure and discouraging the use of consumer products that may bias the sampling results. • At the time of the indoor sampling event, each office occupant should be surveyed again to identify consumer products that may interfere with the test results. • Provide a floor diagram of the office area illustrating the floor layout and all pertinent information such as doorways, chemical storage areas, and utility conduits; on the day of sampling complete the Building Survey Form found in Appendix L of Vapor Intrusion Guidance. • Indoor sources of contamination, such as commercial and household products, should be inventoried and the office building should be screened using a portable field instrument that has a detection limit in parts per billion by volume range to identify indoor sources of contamination so that these items can be removed, if possible, from the premises prior to indoor sampling. • Products that contain volatile chemicals should be listed on the Building Screening Form found in Appendix M of Vapor Intrusion Guidance; • Although Vapor Intrusion Guidance recommends a minimum of three ambient air samples with each indoor air sampling event, provide the location for collecting the one ambient air sample proposed to be collected upwind, and include the approximate height of the Summa canister from the ground noting that ambient samples should be located away from automobiles, gasoline-powered engines, and fuel, oil and chemical storage areas. • Begin and continue ambient air sampling at least one hour and preferably two hours before indoor air sampling begins and continue until at least thirty minutes before indoor air sampling is complete based on the USEPA recommendation as stated in Vapor Intrusion Pathway:A Practical Guideline. • Please clarify whether the soil gas analytical data collected will be compared to the values listed in Table 2 of the Tier 1 Environmental Screening Levels (ESLs) published by the SFRWQCB since the EHD is unaware of any Table 2 ESLs. If you have any questions concerning this matter, please contact Vicki McCartney at (209) 468- 9852 or by email at vmccartney()-sicehd.com. Sincerely, L. McCartney, RENS Nuel C. Henderson, Jr., PG Vi Engineering Geologist Senior Registered Environmental Health Specialist En 9 9 g c: Ms. Jeanne Homsey, PE, ATC Associates Inc., 1117 Lone Palm Avenue, Suite 201, Modesto, California 95351 Mr. James L.L. Barton, PG, California Regional Water Quality Control Board Central Valley Region, 11020 Sun Center Drive, Suite 200, Rancho Cordova, California 95670