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VIRONMENTAL
<br />14EALTHJ,)EPARTMENT
<br />EN SAN JOAQUIN COUNTY
<br />nonny K. Reran, R.E.H.S. 304 East Weber Avenue, Third Floor
<br />D`rectorStockton, California 95202-2708
<br />Al Olsen, R.E.H.S.
<br />7 P,.ogran, Manager Telephone: (209) 468-3420
<br />"ciFSa`' Laurie A. Cotulta, R.E.H.S. Fax: (209) 464-0138
<br />Program Manager -
<br />Unit Supervisors
<br />Carl Borgon", R.E. H.S.
<br />Mike Huggins, R37 H.S., R.D.L.
<br />Douglas W. Wilson, R.E.H.S.
<br />Margaret Lagono, R.E.H.S.
<br />Robert McClellon, R.E.H.S.
<br />Mack Barcellos, R.E.H.S.
<br />APR 15 2004
<br />LAURA ANDREW
<br />SARA LEE BAKERY GROUP
<br />8400 MARYLAND AVENUE
<br />ST LOUIS MO 63105-3668
<br />RE: The Earthgrains Company Facility SITE CODE 19093
<br />2651 South Airport Way RO: 0431
<br />Stockton, California
<br />San Joaquin County Environmental Health Department (EHD) has reviewed Subsurface
<br />Investigation Work Plan, dated February 20, 2004, prepared by Kleinfelder on your behalf for the
<br />above -referenced site. In this report, Kleinfelder proposed the following:
<br />• Advancement of six soil borings, B-1 through B-6, to 35 feet below ground surface (bgs)
<br />to characterize the lithology and assess the vertical extent of impacted soil;
<br />• Collection of five soil samples at depths of 15, 20, 25, 30, and 35 feet bgs in borings
<br />B-1, B'-3, B-4, B-5, and B-6;
<br />• Collection of five soil samples at depths of 10, 15, 20, 30, and 35 feet bgs in boring B-2;
<br />• Analysis of at least two soil samples from each boring; analytical data will be used to
<br />estimate the mass of residual petroleum hydrocarbon impact in the vadose zone;
<br />• Collection of groundwater samples in boreholes B-1 and B-6, at depths of 60, 70, and 80
<br />feet bgs;
<br />• Collection of a groundwater sample from the irrigation well located on an adjacent parcel,
<br />once access is granted by the property owner;
<br />• Commencement of quarterly groundwater monitoring for monitoring wells MW -1, MW -2,
<br />MW -4, MW -5, MW -7, MW -8, MW -12, and MW -13; air-sparging wells SP -1; SP -2, and
<br />SP -4; and piezometers: PZ -1 and PZ -2.
<br />EHD recommends the following to better ensure assessment of the vertical extent of impacted soil
<br />and groundwater:
<br />• Advancement of one additional boring, B-7, to a depth of approximately 35 feet bgs located
<br />adjacent to the sump north of the former dispenser to characterize the lithology and assess
<br />the vertical extent of impacted soil;
<br />• Advancement of at least one cone penetrometer testing (CPT) soil boring to a depth of
<br />approximately 120 feet bgs, using the proposed boreholes located near the former
<br />underground storage tanks to characterize the hydrogeology and lithology, and model
<br />potential contaminant migration pathways;
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