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Mr. Samuel Savig August 22,2001 JI Page 2 of 3 Drilling,Well Construction and Soil Sampling I Three soil borings will be drilled to a depth of approximately 22 to 25 feet bgs at the site at the approximate locations shown on Figure 2. The borings will be drilled in order to collect soil samples and �. to install groundwater monitoring wells. A drilling contractor with a California C-57 license will advance borings using a rig equipped with 8" diameter hollow stem augers. The borings will be completed as groundwater monitoring wells and will be constructed of 2-inch diameter, Schedule 40 i PVC blank and slotted casing. The designated screened interval will consist of 0.010" machine-slotted casing. The wells will be screened from approximately 5 feet above to approximately 15 feet below the i first encountered groundwater. The filter pack will consist of No. 2/12 Monterey sand from the bottoms J of the wells to approximately 2 feet above the tops of the screens. The remaining annular space will be completed with 2 feet of hydrated bentonite overlain by neat cement grout and/or concrete. Each well will be fitted at the surface with a locking cap and water tight; traffic rated well box anchored with a Iconcrete apron. Drilling and well installation will be conducted under the supervision of California Registered Geologist, 3 E The borings will be sampled at 5-foot intervals for soil classification and possible analytical testing. All soil samples will be classified in accordance with ASTM Designation D2488-90, which is equivalent to the Unified Soil Classification System. Soil samples at 5-foot intervals will be subjectively evaluated for the presence of contamination using a photo-ionization detector (PID) or equivalent. Up to three soil samples per boring, dependent upon field evidence of contamination and/or changes in lithology, will be k submitted for laboratory analysis. Soil samples selected for analysis will be immediately capped, labeled y and placed in an ice chest for transport to the laboratory. Sail samples selected for analysis will be submitted to a State-cdrtified laboratory under chain of custody protocol. The samples will be analyzed for TPHg, total petroleum hydrocarbons as diesel (TPHd), and total petroleum hydrocarbons as kerosene (TPHk) using EPA Method 8015; benzene, toluene, ethylbenzene, and xylenes (BTEX) using EPA method 8020; and total lead using EPA method 3050/7420. In addition, one soil sample pre boring (the one with the greatest field evidence of contamination)will be analyzed oxygenated gasoline additives using EPA Method 8260. Drill cuttings will be placed on and covered with plastic sheeting or placed in DOT approved 55-gallon drums. Water generated from equipment decontamination will be contained in labeled DOT approved i drums. The soil and/or drums will be stored on site pending laboratory results and the development of disposal options. Well Development, Surveying and Groundwater Sampling I The elevation of the top of the casing in each well will be surveyed to an accuracy of 0.01 feet. After well completion, an experienced field technician will measure static depth to water and then develop the wells by pumping and surging until turbidity is minimized. A 'minimum of five casing volumes will be purged from each well during development. Groundwater samples will be collected after pH, temperature, and electrical conductivity have stabilized and the wells have recharged to minimum of 80% -of staticR levels. Groundwater samples will be G:1Dam1G ROUNDZEI'I'HORPEISo=u\WPMWS.doc y �� J