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MSpreckels Sugar Tracy, California JOB 96017 The test results indicate an unusual relative concentration of benzene relative to the remainder of the constituents, which are commonly associated with gasoline At this time, there is no apparent explanation for that anomaly. The test results exceed the drinking water standards for benzene MTBE does not have a drinking water standard at this time In order to achieve a determination that no further action is required, the following items will be evaluated. (1) There should be a monitoring well in the downgradaent direction an the shallow groundwater which shows no significant concentrations of hydrocarbon constituents The record shows that the tank was removed in 1985, which is 14 years ago. A downgradient monitoring well which showed no significant concentrations would therefore establish an upper bound to the rate of groundwater migration of fuel constituents . The location of the proposed monitoring well is shown on Figure 2 . The cross section of the proposed monitoring well is shown on Figure 3 . The permit to construct the monitoring well is attached. I have a valid C-57 well drilling contractor' s license . During the drilling of the well, undisturbed soil samples would be taken at 101 , 15 ' and 20 ' deep The soil samples would be examined with a PID an the field and • submitted to a certified laboratory for TPH(g) , BTEX and MTBE The well would become the proposed groundwater monitoring well only in the event that at was not in the zone of impacted soil . In the event that at was in the zone of impacted soil, we would move out 30 more feet and redrill . The well would be logged by a licensed geotechnical engineer (2) The monitoring well would be surveyed into the tops of the other monitoring wells at the site. At the time the monitoring well was sampled, the groundwater elevation at all the wells would be established. The groundwater contour map would be prepared. I am licensed to perform surveys in the State of California (3) The well would be purged of at least 5 well volumes before sampling. A teflon bailer would be used to sample. The person would be a Class A Title 22 sampler The samples would be placed in bottles provided by the testing laboratory The samples would be kept in an ice chest with blue ice for delivery to the certified laboratory an 24 hours . Chain of custody would be established. (4) APPL Laboratories of Fresno would be the certified laboratory performing the testing The groundwater samples would be tested for TPH(g) , BTEX, and oxygenates. 2 I