SITE INFORMATION AND CORRESPONDENCE FILE 1

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ENVIRONMENTAL HEALTAEPARTMENT SAN JOAQUIN COUNTY o Unit superrisors c ?� Donna K.Heran,R.E.H.S. Director 304 East Weber Avenue, Third Floor Carl Bor gman,R.E.H.S. Mike Huggins,R.E.H.S.,R.D.I. Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S • cqC Foae+c• Program Manager Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S Laurie A.Cotulla,R.E.H.S. Fax: (209) 464-0138 Robert M on,R.E.H.S. Program Manager Mark Barcellorcellos,R.E.H.S., GEORGE AND MEI TERANISHI JUN 2 8 2004 1600 DURHAM FERRY RD TRACY CA 95376 RE: GEORGES SERVICE Site Code: 1550 1600 DURHAM FERRY RD TRACY CA 95376 San Joaquin County Environmental Health Department (EHD) has reviewed Additional Site Characterization & 1" Quarter 2004 Groundwater Monitoring (ASC), dated 26 March 2004 and Feasibility Study (FS), dated 28 April 2004, both prepared by Geological Technics, Inc. The work reported in the ASC included installation of four additional groundwater monitor wells (MW-101, 106, 201 and 2X). The lithological information obtained from the borings for these wells fit well with the cross section included in the ASC. The cross section shows four depth zones of interest: • First water zone, monitored by MWA though MW8, with screens set between 5 and 22 feet below surface grade (bsg). Locally, the interval is composed primarily of sand with lesser quantities of silt and clay. • The second laterally extensive sand unit occurs generally between 42 and 50 feet bsg. The second zone is monitored by monitor wells MW-2X, 105, 106, and 101. • The third laterally extensive sand occurs between 55 and 60 feet bsg and it monitored by monitor wells MWA02, 201 and 107. • The fourth laterally continuous sand interval generally falls between 70 and 85 feet bsg and is monitored only by monitor well MW-202. EHD interprets the data from the first water zone to indicate that the plume of impacted groundwater has been delineated in all directions except toward the west and southwest. Impacted groundwater in the second sand unit appears to be extended in a north-south direction and is present in monitor wells MWA06 and MWA01, but is not present in MW- 105 (west), 102 (center to east). Ground water in the former dispenser area in the third sand interval is moderately to lightly impacted, while groundwater in the former underground storage tank (UST) area is not impacted. Ground water in the fourth sand interval, as monitored by MW 202 in the former UST area, does not appear to be impacted.