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Ms. Vera Fischer Page 2 of 5 Groundwater Monitoring Well Installation An intermediate zone monitoring well will be installed at the approximate location shown on Figure 2. Well installation is dependent upon securing an access agreement from the offsite property owner. Prior to drilling, a drilling permit will be obtained from the San Joaquin County Environmental Health Department (EHD). The proposed drilling location will be marked and cleared for underground utilities by Underground Service Alert and a private utility location service. Monitoring Well Drilling, Construction and Soil Sampling A C-57 licensed contractor using hollow stem auger equipment will drill one 8-inch diameter boring to a depth of approximately 70 feet below ground surface (bgs). An experienced geologist will supervise the drilling. Beginning at a depth of 40 feet, the boring will be sampled at five-foot intervals in order to identify lithology and field-screen soils for hydrocarbons. Soil samples will be collected with a split spoon sampler lined with clean brass sleeves. Soil samples will be screened for the presence of hydrocarbons by the use of a photoionization detector (PID). Soil samples selected for laboratory analysis will be capped, labeled and placed in an ice chest pending transport to the laboratory. The boring will be completed as groundwater monitoring well MW-12. To complete the well, 2-inch diameter PVC casing and 0.020 slot screen will be set from the bottom of the boring to grade. To be consistent with the other intermediate zone monitoring wells at the site, it is anticipated that the screened interval will be from approximately 55 to 70 feet bgs. Actual screened interval will be dictated by lithology. Filter pack consisting of#3 sand will be emplaced from total depth to two feet above the top of the screened interval. The remaining annulus will be completed with 2 feet of hydrated bentonite overlain by neat cement grout to the surface. All annular materials will be emplaced with a tremmie system. At the surface the well will be fitted with a locking cap and water tight, traffic rated well box. Proposed construction details are shown on Figure 3. Selected soil samples will be submitted to a state-certified laboratory under chain of custody protocol for analysis. The suite of analyses will include Total Petroleum Hydrocarbons as Gasoline and Diesel (TPHg and TPHd) by EPA Method 8015, and benzene, toluene, ethylbenzene and xylenes (BTEX), fuel oxygenates and lead scavengers by EPA Method 8260. Soil samples may be selected for analysis due to field indications of contamination such as odors, discoloration or high PID readings as well as significant changes in lithology. Surveying, Well Development and Groundwater Sampling The casing collar of the new well will be professionally surveyed to a vertical accuracy of 0.01 feet and a horizontal accuracy of less than one meter. Stallworth Workplan Text