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<br /> Meeks RV (formerly Pacific Auto Center) Page 2
<br /> 25355 North Highway 99 October 8, 2009
<br /> Acampo, California 95220
<br /> The EHD approves the soil analyses for TPH-d, TPH-g, BTEX; 1;27DCA, EDB, and
<br /> physical properties listed above once clarification for analyzing soil samples for TPH-d and
<br /> collecting physical properties has been provided. Since historically soil and groundwater
<br /> concentrations of MTBE, ETBE, TAME, DIPE, and TBA have been non-detect, with few
<br /> exceptions, these compounds may be omitted from the analytical list.
<br /> The EHD approves the following an for soil gas samples collected in Summa TM
<br /> canisters: full-scan volatile organic 'compound that includes BTEX, 1,2-DCA, - EDB,
<br /> naphthalene, 1,1-diflouroethane (leak detector) by method TO-15; and MTBE, ETBE,
<br /> TAME, TBA, and DIPE if there is no additional fee for reporting these,analytes; TPH-g by
<br /> method TO-3 or TO-15; and oxygen, carbon dioxide, and methane by American Society of
<br /> Testing and Materials (ASTM) method 1946.
<br /> In the well installation work plan, ERI proposes to install three monitoring wells (MW-8,
<br /> MW-9, and MW-10) using,a mud-rotary drilling rig.at locations on-,and off-site, illustrated
<br /> on Plate'2 of the work plan. The purpose of the wells.is to define the vertical and lateral
<br /> extent of petroleum hydrocarbon contamination and assess groundwater flow direction
<br /> and hydraulic gradient.. ERI proposes to collect soil samples for lithological evaluation ata
<br /> minimum of ten-foot intervals between surface grade and approximately seventy-five feet
<br /> bsg and at five-foot intervals between approximately sixty-nine and ninety feet bsg, setting 4
<br /> the screens in wells MW-8 and MW-10 between approximately seventy and ninety feet
<br /> bsg. ERI proposes to install MW79, screened between approximately one-hundred-
<br /> twenty-eight and one-hundred-thirty-eight feet bsg while collecting soil samples at the
<br /> same depth intervals as the other two, proposed wells, and collecting soil samples at a
<br /> minimum of ten-foot intervals between approximately ninety and one-hundred-twenty feet
<br /> bsg, and five-foot intervals between approximately one-hundred-eighteen and one-
<br /> hundred-thirty-eight feet bsg. Although the EHD has concerns about collecting soil h
<br /> samples using a mud-rotary drilling rig, the EHD approves the work plan for the installation
<br /> of the three wells.
<br /> ERI proposes to analyze soil and groundwater samples collected quarterly from the newly
<br /> installed wells for TPH-g, BTEX, MTBE, DIPE, ETBE, TAME, TBA, and ethanol. Please 14
<br /> add 1,2-DCA and EDB to the analytical list and omit MTBE, DIPE, ETBE, TAME, and TBA S°
<br /> for the same reasons presented above. 9
<br /> LyI Iii) c�
<br /> Please respond to the comments presented in this letter by November 30, 2009, and
<br /> complete the fieldwork by January 13, 2010. If you have any questions, please contact G
<br /> Vicki McCartney by y telephone at (209) 468-9852 or by email at vmccartnev(U),sicehd.com.
<br /> Sincerely,
<br /> -U�,� � /���� �%i�� amu- /i'tJ •+-�
<br /> Victoria L. McCartney, REHS Nuel C. Henderson, Jr., PG -.
<br /> Senior Registered Environmental Health Specialist Engineering Geologist
<br /> c: Mr. James L.L. Barton, PG, California Regional Water Quality Control Board Central
<br /> Valley Region, 11020 Sun Center Drive, Suite 200, Rancho Cordova, California 95670
<br /> Ms. Tracy Loutsch, Environmental Resolutions, Inc. 601 North'McDowell Boulevard,
<br /> Petaluma, California 94954-2312
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