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Chevron Products Company 2 Chevron Service Station #9-8632, [. .racy Boulevard, Tracy, CA October 2, 2001 groundwater monitoring well to the north of CPT-8 and CPT-9, the installation of one shallow monitoring well in the northeast corner of the site, and the installation of one deep monitoring well in the center of the site between MW- 1 and MW-3 . The specific scope of work is discussed below: • Groundwater Monitoring Wells. Four soil borings will be advanced at the general locations shown on Figure 2 using 8-inch diameter hollow-stem augers to a depth of approximately 20 feet below ground surface (bgs) for the shallow monitoring wells, and to approximately 47 feet bgs for the deep monitoring wells. First groundwater is expected to be encountered at a depth of approximately 7 feet bgs, and a second water-bearing zone is expected to be encountered at approximately 42 to 47 feet bgs. As agreed upon in a telephone conversation on August 14, 2001 between yourself and Mr. Brasher, the total depth of the deep wells will not exceed 50 feet bgs, if a deeper water-bearing zone has not been encountered above that depth. Upon completion of drilling, a 2-inch diameter groundwater monitoring well will be installed in each of the borings. The wells will be screened from approximately 5 feet above to 10 feet below first encountered groundwater in the shallow wells, and approximately 5 feet of screen will be placed in the bottom of the deep wells. • Permitting. The applicable permits for groundwater monitoring well installation and encroachment will be obtained from San Joaquin County and the City of Tracy prior to drilling. • Soil Selection and Analysis. Soil samples will be collected at 5-foot intervals and will be sent under chain-of-custody procedures to a California State-certified laboratory for analysis of total petroleum hydrocarbons quantified as gasoline (TPHg), total petroleum hydrocarbons quantified as diesel (TPHd), and methanol using modified EPA Method 8015 , and benzene, toluene, ethylbenzene, xylenes (BTEX), methyl tertiary butyl ether (MtBE), tertiary butanol (TBA), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (EtBE), tertiary-amyl methyl ether (TAME), 1 ,2-dichloroethane ( 1 ,2-DCA), 1 ,2- dibromoethane (EDB), and ethanol by EPA Method 8260. Soil samples will not be collected form the shallow monitoring well in the northwest corner of the site due to its close proximity to the deep monitoring well. • Monitoring Well Development and Sampling. Following installation, the monitoring wells will be developed by rigorously surging the wells over the length of the screen interval and by purging approximately 10 casing volumes of water. After well development, groundwater samples will be collected and sent under standard chain-of-custody procedures to a California State-certified laboratory. The groundwater samples will be analyzed for TPHg, TPHd, and methanol using modified EPA Method 8015, and BTEX, MtBE, TBA, DIPE, EtBE, TAME, 1 ,2-DCA, EDB, and ethanol by EPA Method 8260. 19Chevmn\98632\Reports\98632 well install WP 2001 .doc